WO2013013580A1

WO2013013580A1 - Reconfigurable numerical control system, and reconfiguration method

Info

Publication number: WO2013013580A1
Application number: PCT/CN2012/078564
Authority: WO
Inventors: 江俊逢
Original assignee: Jiang Junfeng
Priority date: 2011-07-22
Filing date: 2012-07-12
Publication date: 2013-01-31
Also published as: CN102402197B; CN102402197A

Abstract

Disclosed are a PC based, all-round open, and standardized reconfigurable numerical control system and a reconfiguration method thereof. Proposed is a procedure-oriented and open processing procedure model. The configuration method configures control resources according to the control flow, is independent of software and hardware platforms such as the number of digits and speed of the processor, operating system, etc. and independent of programming interfaces, so has good reconfigurability and high reliability. The present application transforms the real-time control of the cutter path curve into the real-time sending of the simplest linkage command, and is capable of simple and reliable high-speed high-precision multi-axle synchronization. For a reconfigurable production line consisting of a plurality of numerical control machine tools, digitized fixtures, and handling mechanical hands, etc., the present application has advantages such as integrated control, high reliability, simple structure, and low price, etc.

Description

Reconfigurable numerical control system and reconstruction method

技术领域 Technical field

The invention belongs to the field of advanced control and advanced manufacturing, and particularly relates to a PC-based, all-round open, standardized reconfigurable numerical control system and a reconstruction method thereof, so as to adapt to the requirements of the digital control system of the reconfigurable manufacturing system.

技术背景 technical background

The reconfigurable manufacturing system is the research frontier of advanced manufacturing and the development direction of future manufacturing systems. In 1998, the National Research Council published a study on 'The Challenges of Manufacturing in 2020', ranking reconfigurable manufacturing systems as the top 10 key technologies. Decisive for reconfigurable manufacturing systems is the reconfigurable machine tool RMT (Reconfigurable Machine Tools). For more than ten years, digital information technology has advanced by leaps and bounds, and reconfigurable machine tools have not progressed. The reason is that reconfigurable machine tools must be based on reconfigurable CNC systems. Without a reconfigurable CNC system, the reconfigurable machine tool is without a meter.

The reconfigurability of CNC systems has become a key technology to be solved in reconfigurable manufacturing systems.

The reconfigurable CNC system should be an open digital control system, which is the consensus in the field.

Since the development of the first electronic tube control system by MIT in 1952, after the transistor, integrated circuit, small computer, and microcomputer, the numerical control system has developed into a PC-based open CNC system in the 1980s, which has produced Three modes of open CNC system: PC embedded NC mode, NC embedded PC mode, soft open mode.

NC The so-called motion controller-based open CNC system embedded in PC mode has become the mainstream of the existing open CNC system. The motion controller has become a high-tech industry and is popular all over the world. The open motion controller is hailed as a new generation of industrial controllers in the United States and is considered to be the third industrial revolution in the future.

IEEE (Institute of Electrical and Electronics Engineers , Institute of Electrical and Electronics Engineers) The definition of an open CNC system is: 'A system that conforms to the system specification can run on different platforms of multiple vendors, can interoperate with other system applications, and has a consistent style of users. user-interface. '

Chinese national standard "GB/T 18759. 1-2002 • Mechanical and electrical equipment • Open CNC system • Part 1 The General Principles grasps the essence of the IEEE definition and follows the basic principles defined by the IEEE. In Section 3.1, the openness is defined as the 'plug and play' of the application software, and the open CNC system is defined as:

' The application software is built on a system platform that conforms to the system platform of openness, scalability, and compatibility, so that the application software has portability, interoperability, and consistency of human-machine interface. '

The open architecture is the key technology for high performance and intelligent digital control. However, in the past three decades, under the misguided definition of IEEE, as the literature "Review of the application of high-performance motion control in numerical control systems" (in "Information and Control", 2003, No. 3, China Automation Society and Chinese Academy of Sciences, Shenyang jointly organized by Institute of automation, author: Wang Junping, Wang, Jing Zhongliang, Quanshi) points out, 'open architecture has not yet unified, clear concept connotation, system implementation technology is still in contending era', 'open architecture The research is still in its infancy.'

From an information theory point of view, the numerical control system only decompresses the digital control information compressed in the tool path curve and the feed rate. In the existing open CNC system based on IEEE definition, the interpolation iterative control method is a decompression method of digital control information.

The basic technical solution of the interpolation iterative control method is for a given tool path (Tool Path) and the feed rate of the tool, under the control of the real-time operating system, with the interpolation period as the time-sharing period, the interpolation control algorithm is used to calculate the digital control information of the relevant coordinate axes in real time, and distribute it to the servo drive in real time. Execution to control deterministic motion relationships between mechanical systems. In each interpolation cycle, the digital control information generated by the interpolation is immediately distributed to the servo drive for immediate execution on the one hand, and iterated as the input of the next interpolation cycle to generate the next digital control. Information, which constitutes a real-time iteration of digital control information. Following the beat of the interpolation period, the digital control information is continuously generated, distributed, transmitted, and executed, and then repeated in a process iterative manner to constitute a real-time iteration of the control process.

The inventors found that there are four basic reasons why the existing open CNC system based on IEEE definition has no reconfigurability:

First, platform relevance

The so-called platform independence generally means that the application software can run on multiple different kinds of CPUs and on multiple operating systems. The former is hardware platform independence, and the latter is software platform independence.

Chinese national standard "GB/T 18759. 1-2002 • Mechanical and electrical equipment • Open CNC system • Part 1 General Principles The basic architecture of the open CNC system is divided into application software and system platform. The system platform consists of hardware platform and software platform. The so-called hardware platform is the basic component of the software platform and application software running, at the bottom of the basic architecture; the so-called software platform is the basic component of the application software operation, between the hardware platform and the application software of the basic architecture. The so-called NC core software is the basic software in the application software, that is, the application software module involving motion control, axis control and motion control management. For the simplicity of the description, the NC core software is simply referred to as the numerical control application software.

The software platform generally includes an operating system, a graphics system, and an application programming interface APT, wherein the core is a real-time operating system.

From the development history of computer and computer applications, it is an epoch-making progress to use a multi-tasking operating system that runs multiple user programs in a time-sharing manner. However, in essence, the multitasking operating system is only a management mechanism for internal and external resources and a response mechanism for responding to changes in internal and external environments to adapt to internal and external resource management and internal and external environmental changes.

In the existing open CNC system based on IEEE definition, the interpolation iterative control method transforms the management mechanism and strain mechanism of the real-time operating system into a universal control mechanism, and the real-time operating system becomes a real-time interpolation iteration to generate The real-time control center of digital control information, the existing CNC system forms a system architecture centered on the real-time operating system. The operation rules of the interpolation iterative control algorithm are closely coupled with the task scheduling rules of the real-time operating system to form a real-time digital control method, namely the interpolation iterative control method. The interpolation iterative control method runs through the entire history of digital control technology and numerical control system, and creates the 'interpolation era' of the numerical control system. .

In the existing open CNC system based on IEEE definition, the interpolation iterative control algorithm is a decompression method of digital control information, and the interpolation calculation must be performed in real time under the control of the real-time operating system. The real-time operating system has high-precision timing function, multi-level interrupt nesting processing mechanism and real-time scheduling mechanism, and its core is process scheduling and thread scheduling. Real-time complexity complicates process scheduling and thread scheduling. Parallel algorithms further complicate process scheduling and thread scheduling. The concurrency of thread concurrency is extremely complex compared to the concurrency of machine instruction-level pipelines and the concurrency of processor-level processes.

Processes and threads, coupled with parallel algorithms, result in a highly complex real-time operating system and a high degree of complexity in CNC applications. For high-speed, high-precision multi-axis systems, CNC applications are bound to become a large and complex interrupt system that uses parallel algorithms, multi-process/multi-threaded nested calls, and multiple real-time nested interrupts.

The problem is that once the motion speed increases, or the motion accuracy increases, or the linkage axis increases, or the linkage parameters increase, the interpolation cycle of the real-time operating system must increase exponentially, requiring more bits and higher speed CPUs, and more. More real-time real-time operating system, more optimized real-time scheduling capabilities, and more advanced interpolation iterative control algorithms.

The problem is that in order to develop such a large and complex interrupt system, it is necessary to be proficient in digital control technology, master the computer software and hardware architecture, and be proficient in parallel algorithms and multi-threaded programming. This means that CNC applications become so-called expert systems, ie only A system that can be developed by a compound expert who is proficient in the above technology, the user cannot perform secondary development, and thus completely loses its openness.

Therefore, the open-ended existing CNC system based on IEEE is completely 'computerized'. In terms of architecture, it becomes a general-purpose computer system that needs to configure a real-time operating system. The numerical control application software is only one dedicated application system, and its opening is open. Sex can only be defined as 'plug and play' for CNC applications.

It can be seen that, in essence, the existing open CNC system based on IEEE definition does not have platform independence, but on the contrary, has platform correlation. For high-speed and high-precision multi-axis systems, it is strongly related to the platform. Sex.

Since the existing open CNC system based on IEEE has a strong correlation with the platform, it essentially loses the foundation of reconstruction.

Second, the real-time control process is not reconfigurable

In the existing open CNC system based on IEEE definition, the real-time control process is not only an iterative process of digital control information but also an iterative process of real-time control process. It is inseparable from the interpolation iterative control algorithm, and the high-speed and high-precision interpolation iterative algorithm is natural. Become the core technology in the existing CNC technology. Therefore, Japan's OSEC program (Open The System Environment for Controller believes that open CNC systems without advanced control algorithms are only evolutionary, not ideal and revolutionary.

In terms of architecture, the existing open CNC system based on IEEE definition is divided into two parts: system platform and application software. The application software is further divided into human-machine control layer and motion control layer. The motion control layer is the core of the CNC system to complete the real-time control process, and is composed of some standard components. Obviously, this is an architecture for application configuration. This means that existing open CNC systems based on IEEE definitions are object oriented rather than process oriented.

The core issue of digital control systems is the real-time control of the toolpath curve. Corresponding to the reconstruction of the mechanical system, the real-time control process of the tool path curve necessarily needs to be reconstructed.

In the existing open CNC system based on IEEE definition, for different toolpath curves, such as straight lines, arcs, parabolas, involutes, NURBS curves, etc., the corresponding interpolation iterative algorithm must be developed and applied in the numerical control application software. Configure the corresponding real-time control module. Therefore, corresponding to the reconstruction of the mechanical system, the reconstruction of the real-time control process necessarily involves the modification of the real-time control module, or the replacement and addition of the real-time control module. Apart from this, there is no other technical means.

Obviously, this is far from the connotation of the reconfigurability of digital control systems.

The inventors have found that for digital control, the process is more essential than the object. Digital control in a digital control system is a process, not an object. However, existing open CNC systems based on IEEE definitions are object oriented rather than process oriented.

In the interpolation iterative control method, the real-time control process is the process of generating the coordinate value increment under the interpolation period control, the allocation process, the sending process, and the execution process. Thus, the real-time control process and the geometric characteristics of the tool path curve, the process characteristics of the machining process, the mechanical system Kinematics / The dynamic characteristics are inseparable, and are inseparable from the hardware platforms such as the number of bits of the CPU and the operation speed. They are inseparable from the software platforms such as the real-time operating system, and are inseparable from the interpolation iterative algorithm. This fundamentally limits the reconstruction of the real-time control process. In other words, in the existing open CNC system based on IEEE definition, the real-time control process of the tool path curve cannot be opened and has no reconfigurability.

Third, the communication cycle is the system parameter

Networking is an important technical feature of advanced manufacturing technology.

Chinese National Standard 'GB/T 18759.1-2002•Mechanical and Electrical Equipment•Open CNC System•Part 1: General • 5. 2. 4. 2' It is stipulated that external communication should comply with relevant national or international standards, and internal communication should conform to the ISO standard communication model.

External communication is used between the CNC system and the shop management network. The port can be called a network interface, such as an industrial Ethernet interface or other fieldbus (Field). Bus).

Then, for the internal communication interface, the Chinese national standard "GB/T 18759. 3-2009•Mechanical and electrical equipment•Open CNC system•Part 3 Bus interface and communication protocol》Based on the ISO/OSI open system interconnection reference model, a fieldbus is standardized, called 'open CNC system bus ', for connecting 'CNC devices, servo drives, spindle drives, sensor devices, I/O devices' to achieve these 'digital, two-way, multi-point communication between devices' and to meet system-to-cycle , real-time, synchronization, reliability, security, openness and other requirements. Another draft of the CNC fieldbus standard "NCUC-Bus Fieldbus Protocol Specification (Draft) for machine tool numerical control system" has been published and is based on the ISO/OSI open system interconnection reference model.

As is well known, the ISO/OSI Open Systems Interconnection Reference Model is aimed at communication models between computer networks. The fieldbus standard simplifies the bus architecture, and is mainly composed of a physical layer, a data link layer, and an application layer. The field bus causes the communication cycle to become another system parameter, and a series of problems such as real-time communication protocol and compatibility of data representation cause high complexity and high cost of internal communication.

Corresponding to the reconstruction of the mechanical system, the data format of the digital control information in the real-time control process, including the feed equivalent (nano or micron), the number of bytes of data, etc., will change. A user layer communication protocol must be established in the field bus to standardize data formats, timing relationships, and error correction methods in data exchange within the open CNC system. Thus, similar to the interpolation cycle in the real-time operating system, the communication cycle in the fieldbus becomes a factor that restricts the reconfigurability of the digital control system.

For reconfigurable CNC systems, a large amount of computing resources must be used to support various fieldbuses (eg CAN, Profibus, Sercos, etc.).

Fourth, the consistency of the programming interface and the human-machine interface

In the open-ended existing CNC system based on IEEE definition, the G code standard is adopted as the programming interface of the NC machining program. When the paper tape was used as the basic physical medium for input in the 1950s, the code standard for the paper tape perforation, that is, the G code standard, was established for the specification of characters on the paper tape.

G The code standard is the original product of the initial stage of information technology. Due to the limitation of the paper tape, there is inevitably a defect that the amount of information is too small. Therefore, each manufacturer has extended the basic semantics of the G code, resulting in the dependence of the G code program and the corresponding hardware. The CNC machining program is not interchangeable between different CNC systems, resulting in incompatibility between various CNC systems. . Therefore, as a programming interface, the G code standard does not have the consistency of the human-machine interface, which becomes one of the bottlenecks for the further development of the numerical control technology, and also restricts the openness and reconfigurability of the digital control system.

The above four problems lead to the existing open CNC system based on IEEE definition, there are only three technical solutions to solve the openness of the digital control system.

One is to develop more bits, higher speed CPUs and more real-time operating systems with more digits and real-time performance. For example, in 2009, China's national 'high-end CNC machine tools and basic manufacturing equipment' technology major project plans to include 64-bit CPU, 64-bit real-time operating system, and multi-axis linkage CNC system with an interpolation period of 0.125ms as a key technology.

The second is to develop more advanced interpolation iterative control algorithms. For example, Japan has developed a 64-bit ultra-fast chip and NURBS interpolation iterative control algorithm for motion controllers driven by the OSEC program.

The third is to develop a fully soft open CNC system based on ultra-high speed processor and real-time operating system. The so-called all-soft open CNC system, in the image, is to fully PC the digital control system with the support of real-time operating system.

Obviously, the above three technical solutions all rely on the real-time operating system, and the real-time control process of the tool path curve cannot be opened. A serious fact is that in the existing open CNC system based on the IEEE definition, corresponding to the reconstruction of the mechanical system, especially the reconstruction corresponding to the high-speed and high-precision multi-axis system, whether it is NC embedded PC mode or soft open The mode can not solve the above four problems, in particular, can not solve the reconfigurability of the real-time control process, can only re-develop that large and complex interrupt system.

Therefore, the Chinese national standard 'GB/T 18759. 1-2002•Mechanical and electrical equipment•Open CNC system•Part 1 General's no technical definition of the reconfigurability of the CNC system, nor any description of the reconfigurable CNC system, only in 4. 5. The two models of reconfigurability are listed as the highest level of open CNC systems to be realized. In other words, reconfigurability is only a wonderful idea for existing open CNC systems based on IEEE definitions.

The inventors found that the IEEE definition of an open CNC system is the root cause of the development of the reconfigurable CNC system. The primary factor is the control concept generated by the IEEE definition. In terms of concept, it is necessary to change the existing digital control technology and establish a control concept centered on the work machine. The numerical control system is for the working machine, and its task is only to manufacture digital control information, that is, multi-dimensional associated data flow, for the working machine, and the multi-dimensional associated data flow cannot entrain the interpolation cycle, communication cycle, contour step length and the like which are not required by the working machine. Other information.

For digital control, the process is more essential than the object. Digital control in a CNC system is a process, not an object. The architecture of the existing CNC system under the IEEE definition is similar to the Ptolemy system in the history of astronomy, which is due to the mistake of concept.

The inventors further discovered that there are three principle errors in the IEEE definition.

IEEE The first principled error defined is that, in terms of control concepts, the IEEE defines the CNC system as a real-time command center that controls the working machine, without the concept of associated data streams.

IEEE The second principled error of the definition is that, in terms of architecture, the IEEE definition ignores the process essence of digital control, object-oriented rather than process-oriented, without the concept of control flow, defining the numerical control system as a real-time operating system that needs to be configured. General purpose computer system.

IEEE The third principle error defined is that in the control method, the IEEE definition ignores the interpolation iterative control algorithm is only a decompression method of digital control information, so that the management mechanism of the internal and external resources of the real-time operating system and the response to internal and external environmental changes The strain mechanism is regarded as a universal control mechanism, which closely couples the operation rules of the interpolation iterative control algorithm with the task scheduling rules of the real-time operating system to form a real-time control method.

Therefore, the IEEE definition necessarily leads to the following problems:

1) Everything is in the process, and it is necessary to traverse the stages of production, development, and extinction and evolve the hierarchical structure. The structures evolved by things at different levels of the process become objects. Everything is implemented in the process.

Objects are just a kind of artificial abstraction about things in a particular hierarchy, and processes are the dynamic behavior of things moving in different levels of structure. The IEEE definition completely ignores the process essence of digital control, and regards the digital control process as an object, which leads to iteration of digital control information and iteration of control flow. It is impossible to involve the openness of digital control information, the openness of digital control process and digital control. The openness of the interface between processes.

2), IEEE defines the digital control system For the center, the defined openness is the openness of the computer system itself. The architecture of the so-called open CNC system is transplanted from the computer system. It is an object-oriented architecture to realize the modularization of the control software. Reflects the technical characteristics of the CNC system throughout the control process.

3 The IEEE definition fails to examine the architecture of the open CNC system from the macroscopic view of the manufacturing system, and adopts the architecture of the general computer system, resulting in an open concept that is ambiguous and has not been unified. Descriptive vocabulary such as interoperability, portability, scalability, and interchangeability become open so-called technical specifications that hinder The standardization process of the digital control system.

4 IEEE defines object-oriented rather than process-oriented, ignoring the essence of computer numerical control, CNC system is 'computerized', and the development of digital control technology is led to the so-called 'advanced control algorithm' (Japan OSEC plan), plug-in Complementing the accuracy and speed of the iterative control algorithm, thus misleading the development direction of digital control technology.

5), digital control system The core issue is the openness and reconfigurability of real-time control processes. In the open CNC system defined by IEEE, the real-time control module cannot be opened due to object orientation, which fundamentally restricts the development of the digital control system.

6 The IEEE defines an architecture based on a general-purpose computer system, which is limited to the functional division of numerical control software and the operational interface between them. The process characteristics of digital control lack the definition of systematic theory. Therefore, the digital control system It is defined as a general-purpose computer system equipped with numerical control software, thereby essentially defining an open digital control system as a rigid integrated manufacturing system for manufacturing digital control information.

7), the IEEE definition is not based on the working machine, but on the digital control system. As a center, a large amount of redundant information such as interpolation period and contour step size is generated, which violates the principle of simplicity. This redundant information consumes a lot of computing resources and violates economic principles.

8 The openness of the process is completely different from the openness of the object. The openness of the process necessarily involves the control flow of the generation, distribution, transmission, and execution of digital control information. The IEEE defines no concept of controlling the process at all.

IEEE-defined open digital control system The architecture is not an architecture that configures control resources in accordance with the control flow of manufacturing digital control information.

9), the IEEE definition does not regard digital control information as a product, and does not involve the openness of digital control information.

10 ), G code standard is the programming interface used by existing CNC programs. The G code programming interface does not have the consistency of the human machine interface. The IEEE definition of the human-machine interface is too abstract, and the so-called 'consistency of human-machine interface' avoids the openness of the programming interface.

Therefore, the IEEE definition is not an open definition of a computer numerical control system. It merely attempts to standardize the 'plug and play' problem of application software. It does not solve the openness of the digital control system. Instead, it is numerically The control system is forced to be a special computer system under the general computer system architecture, so that the development of the digital control system is firmly nailed to the 'interpolation era'.

In summary, in the existing open CNC system under the umbrella of the IEEE defined misconception, the digital control information produced by the numerical control system, the method of manufacturing digital control information, and the process and process interface for manufacturing digital control information are It is closed, non-standard, and non-reconstructible. The digital control information produced becomes an internal item of the existing numerical control system. This is fundamentally negated The openness and reconfigurability of the digital control system artificially complicate the existing digital control technology with the existing open CNC system, which is a numerical control system. The reconstruction has set up insurmountable obstacles, which will inevitably lead to the failure of the existing open CNC system to evolve into the control machine that the third industrial revolution hopes.

The inventor abandoned the IEEE definition of an open CNC system and defined the open CNC system as:

' The so-called open CNC system is a computer numerical control system that configures the embedded subsystem according to the control flow. It has an open human-machine interface, open digital control information, an open digital control information manufacturing method, an open digital control information manufacturing process, and digital Control an open interface between the information manufacturing process and open application software. '

This definition also applies to the embedded subsystem and is therefore a combination of systematics and fractal geometry. In the defined open CNC system, there is no iteration of the digital control information and iteration of the control flow. The topology of the control information flow is a linear topology. The openness of application software is 'plug and play'.

The openness defined by the IEEE only covers the openness of the application software and the openness of the human-machine interface when operating the computer.

This definition of the inventor shows that the openness of the open CNC system has the following five aspects:

1 ), the openness of the human-machine interface, including the human-machine interface in all control process interfaces of the digital control information manufacturing process, especially the openness of the programming interface;

2) the openness of digital control information;

3) the openness of the manufacturing method of digital control information;

4) The openness of the manufacturing process of digital control information;

5) The openness of the interface between the digital control information manufacturing process.

The openness of the digital control information refers to the openness and transparency of the digital control information generated in the digital control information generating unit.

The openness of the so-called digital control information manufacturing method refers to a manufacturing method that allows a user (or developer) to construct or integrate his own digital control information, that is, the real-time control method is fully softwareized and the software is plug-and-play.

The so-called openness of the digital control information manufacturing process refers to the openness and transparency of each sub-process of digital control information.

The internal interface of the CNC system is used to exchange information between the internal functional components of the system.

The openness of the interface between the so-called digital control information manufacturing processes refers to the openness of the internal interface.

The so-called openness of the human-machine interface refers to the openness of the programming interface.

It can be seen that the definition of the above-mentioned open numerical control system of the inventor reflects the standardization problem proposed by the development environment of the modern manufacturing industry to the control machine, so as to adapt to the standardization process of the working machine, the power machine and other industries.

The inventor invented the data flow association control method (Data- in the invention patent "Data Flow Control Method and Architecture of Computer Digital Control System" (Chinese Patent No.: ZL200710124304.9, Authorization Announcement Date: August 19, 2009) Stream Related Control, DRC control), the existing CNC system has bid farewell to the era of interpolation, entered the era of data flow correlation control, and produced a new generation of control machine, namely the data flow correlation control machine (DRC control machine).

The inventor is inventing the patent "a standardized control machine" (application number: 200910110439.9 PCT International Application No.: PCT/CN2010/072914) discloses a standardized DRC control machine and a reconstruction method thereof, which configure control resources in accordance with a control flow for generation, distribution, and execution of digital control information, the standardized DRC control machine The digital control information generating unit, the digital control information distributing transmitting unit and the digital control information executing unit are constituted.

The inventor regards digital control information as a product, and the process of manufacturing digital control information by generating, distributing, transmitting, and executing digital control information is called a control flow.

According to the process flow, the corresponding production equipment is configured and professionalized and standardized production is the only way for the manufacturing industry to go through. Obviously, the process flow is the basis for division of labor, professionalization, and standardized production. Considering digital control information as a product, there must be a process flow for manufacturing digital control information.

Just as mechanical processing must be configured in accordance with the mechanical manufacturing process, the corresponding embedded subsystem must be configured in the information manufacturing process in accordance with the control flow for manufacturing digital control information.

The inventor divides the control flow into three sub-processes: a digital control information generation process, a digital control information distribution transmission process, and a digital control information execution process.

The inventor found that the process of digital control information generation, including the decompression process of digital control information, the optimization process of digital control information, and the compensation process of deterministic error, should be the 'strategy of tactics, winning thousands of miles away', is a non- Real-time process. The process of assigning and transmitting digital control information is like 'military order mountain', and the execution process of digital control information is more 'booming speed', all must be real-time.

According to the control flow for manufacturing digital control information, the architecture of the open CNC system can be decoupled into a digital control information generating component (digital information manufacturing system), a digital control information distribution transmitting component (data flow controller), and a digital control information executing component. Three functional components (servo drive and I/O device).

In the digital control technology, the discrete position information in the form of '1' '0' is generally referred to as a step type, and the discrete position information composed of increments of coordinate values is referred to as an incremental type.

Set the tool path (Tool The Path) curve is a function of eight variables such as X, y, Z, A, B, W, E, and H. Where X, y, Z, A, B are the coordinate axes of the linkage, W, E, and H are parameters that require real-time control (for example, W is the width of the laser pulse, E is the energy of the laser pulse, and H is the frequency of the laser pulse). For data flow association control, there is no essential difference between the process parameters and the coordinate values that need to be controlled in real time. The switch that controls the process parameters can be regarded as a virtual coordinate axis, and the parameter value is regarded as the coordinate value of the virtual coordinate axis. Therefore, the coordinate axis linkage and the real-time control of the process parameters are unified, which is called multi-axis multi-parameter linkage. In the present invention, the coordinate axis includes a virtual coordinate axis.

Table 1 is a schematic diagram of the 8-linked multi-dimensional associated data stream.

Table 1

△t₁ △t ₁	△t₂ △t ₂	… ...	△t_i △t _i	… ...	△t_n Δt _n
△X₁ △y₁ △Z₁ △A₁ △B₁ △W₁ △E₁ △H₁ △X ₁ △y ₁ △Z ₁ △A ₁ △B ₁ △W ₁ △E ₁ △H ₁	△X₂ △y₂ △Z₂ △A₂ △B₂ △W₂ △E₂ △H₂ △X ₂ △y ₂ △Z ₂ △A ₂ △B ₂ △W ₂ △E ₂ △H ₂	… … … … … … … …... ... ... ... ... ... ... ...	△X_i △y_i △Z_i △A_i △B_i △W_i △E_i △H_i △X _i △y _i △Z _i △A _i △B _i △W _i △E _i △H _i	… … … … … … … …... ... ... ... ... ... ... ...	△X_n △y_n △Z_n △A_n △B_n △W_n △E_n △H_n △X _n △y _n △Z _n △A _n △B _n △W _n △E _n △H _n

In Table 1, the time T is discretely divided into n intervals: Δ t _i , i = 1,..., n . Δ t _i (i = 1,..., n) is called the T-segment of the tool path curve. The coordinate increments of X, y, Z, A, B, W, E, H, etc. in Δ t _i are discretely Δ X _i , Δ y _i , Δ Z _i , Δ A _i , Δ B _i , △ W _i , △ E _i , △ H _i . The micro-line segments Δ L _i ( Δ X _i , Δ y _i , Δ Z _i , Δ A _i , Δ B _i ) are referred to as L-segments of the tool path curve.

In the real-time control process, X-axis to the first advanced △ X _1, △ t ₁ and then through the feed △ X _2, until _{△ X n, y, Z,} A, B, W, E, H isometric well. Therefore, Δt _n is redundant. In addition, in order to unify the control steps, Δt _{0 is added} . Δt ₀ is set independently of the tool path curve, and for example, Δt _{0 is} set to Δt _n . Adjust the subscripts 0, 1, ..., n-1 to 1, ..., n. For the convenience of the description, and different from the interpolation period, Δ t _i (i = 1,..., n) in the T segmentation is referred to as a control rhythm.

Table 1 indicates that for data flow correlation control, there is no essential difference between the process parameters and the coordinate values that need to be controlled in real time. The switch that controls the process parameters can be regarded as a virtual coordinate axis, and the parameter value is regarded as a virtual coordinate axis. Coordinate values, so that the coordinate axis linkage and the real-time control of the process parameters are unified, called multi-axis multi-parameter linkage. In the present invention, the coordinate axis includes a virtual coordinate axis.

It can be seen that the digital control information of the tool path curve includes two parts. The first part is the L segmentation, which describes the coordinate value increment when the related coordinate axes are linked and the required linkage, which is used to control the linkage of the relevant coordinate axes to produce the required composite displacement. The second part is a T-segment, describing the follow-up between the synthetic displacements, used to control the time interval between the synthetic displacements. The L segmentation also includes a quasi-deterministic error such as a deterministic error or a thermal deformation error such as a backlash, a pitch error, a non-perpendicularity, and a non-parallelism error between the drive chains.

The L segmentation of the toolpath curve forms an associated data stream under the control of the T segmentation. According to the '1' '0' form or the coordinate value increment form of the discrete position information, the associated data stream can be divided into a stepped associated data stream and an incremental associated data stream.

According to the given data format, the digital image generated by the L segmentation of the tool path curve in the storage space is called the linkage table of the tool path curve. According to the given data format, the digital image generated by the T-segment of the tool path curve in the storage space is called the follower table of the tool path curve.

Obviously, the core task of digital control technology is to generate the linkage table and the follower table of the tool path curve. The so-called real-time control is based on the control in the follow-up table. The rhythm assigns a coordinate value increment in the linkage table to the corresponding servo drive.

In the existing open CNC system based on IEEE definition, L segmentation is dynamically generated in the real-time control process. The control rhythm Δ t _i (i = 1,..., n) is called the interpolation period and is of equal length. Under the control of the real-time operating system, the interpolation iterative control algorithm generates Δ L _i ( Δ X _i , Δ y _i , Δ Z _i , △ A _i in the interpolation period Δ t _i (i = 1,..., n) , △ B _i ). The interpolation cycle thus becomes a system parameter.

In the data stream association control, the digital control information generating component does not need to configure the real-time operating system, there is no interpolation period, and the control rhythm Δ t _i is not equal in length.

It is clear from Table 1 that the basic problem of digital control is to make associated data streams. The basic problem with real-time control processes is the real-time control of the associated data streams.

For a given workpiece, the so-called digital control information generation process is a process in which the digital control information generation component manufactures the associated data stream, that is, the linkage table of the tool path curve and the generation process of the follower table.

The digital control information generating unit generates a DRC numerical control program in accordance with the order determined by the machining process.

DRC The NC program consists of motion commands for controlling the machining process of the workpiece. The motion instructions include a status command, a switch command, and a track command. The status command is used to operate the auxiliary function; the switch command is used to control the I/O device; the track command is used to control the servo drive device to complete the path of a tool path curve.

The digital control information generating component generates a linkage table of the tool path curve by discrete geometric programming, generates a follower table of the tool path curve through discrete motion planning, and generates a linkage table and a follower table of the standard file form according to the given data format.

Generally, the conventional PLC is used to control the tool magazine, or the soft PLC is used to generate the control flow of the combination logic to control the tool change process in the tool magazine. As a conventional technique, the present invention does not relate to a control flow for tool magazine control.

DRC The numerical control program is a fully digital, commercialized 'digital control information' product manufactured by digital control information generating components. The generation process of the DRC NC program is a programming process using motion instructions. Therefore, the digital control information generating component is not only an open platform for numerical control programming but also an open development platform for numerical control technology.

The so-called digital control information distribution process is that the digital control information distribution transmitting component allocates the coordinate value increments in the linkage table to the relevant servo driving device, for example, Δ X _i , Δ y _i , Δ Z _i , Δ A _i , △ B _{i is} assigned to servo drives of five coordinate axes such as X, y, Z, A, and B.

The so-called digital control information transmission process is the digital control information distribution and transmission component according to the control The rhythm controls the transmission of digital control information in real time.

The so-called digital control information is executed by the servo drive device to write coordinate values into the position loop and drive the coordinate axis feed.

In the DRC control machine based on data stream association control, the generation of digital control information is not real-time, and the distribution and execution of digital control information are real-time.

The inventor found that if the structure of the DRC NC program is improved, the digital control information distribution process is transformed into a non-real-time process, so that the digital control information distribution process can be separated from the digital control information transmission process, and the control flow can be divided into digital control information. Four sub-processes: generation process, digital control information distribution process, digital control information transmission process and digital control information execution process, decoupling the architecture of open CNC system into digital control information generation component, digital control information distribution component, digital control Four functional components, such as an information transmitting unit and a digital control information executing unit.

Then, the inventor further found that the control flow of the digital control information is divided into the generation process, the distribution process, the transmission process, and the execution process, which leads to a significant improvement of the architecture of the DRC control machine, and becomes a PC-based, all-round open Standardized reconfigurable CNC system.

发明内容 Summary of the invention

Data-stream Related Control (DRC Control) The purpose is to propose a PC-based standardized control machine (referred to as DRC control machine) that controls information, control methods, control processes and architecture for the third industrial revolution to adapt to the third industrial revolution. Requirements for the CNC system.

Non-reality based on digital control information distribution process Timely, the present invention improves the DRC control machine, and proposes a PC-based, all-round open, standardized reconfigurable numerical control system. The invention also proposes a digital control method and a reconstruction method based on the digital control system.

The technical solution of the present invention is explained below.

A reconfigurable numerical control system, including a PC system, a data flow controller, a servo drive device, an I/O device, a serial interface, a distribution interface, a linkage interface, an I/O interface; the PC system is connected to the data flow controller through a serial interface; the data flow controller Connecting to the servo drive device through a distribution interface and a linkage interface, the data flow controller is connected to the I/O device through an I/O interface;

The PC system is configured to generate a DRC numerical control program for controlling a workpiece machining process, including a state instruction generation module, a switch instruction generation module, a track instruction generation module, and a DRC numerical control program generation module; and the state instruction generation module is configured to generate a control auxiliary process State instruction; the switch instruction generation module is configured to generate a control The switching instruction of the I/O device; the state instruction generating module is further configured to generate a reconstruction instruction, where the reconstruction instruction is used to modify the state instruction and the interpretation program of the switching instruction. The trajectory command generating module is configured to generate a trajectory command for controlling a servo drive device to complete a path curve pass process; the DRC NC program generating module is configured to link a state command, a switch command, and a trajectory command to a DRC numerical control according to a machining process a program; wherein the trajectory instruction generation module includes a discrete geometric planning module and a discrete motion planning module; the discrete geometric planning module is configured to generate a linkage table of L segments storing a tool path curve; and the L segmentation is used to control coordinates The shaft linkage generates a synthetic displacement; the linkage table is divided into an axis linkage table of each axis, and the axis linkage table is used for storing the L segmentation component of the relevant coordinate axis, and controlling the coordinate axis to generate the axis displacement; the discrete motion planning module is used a T-segment of the tool path curve and a follow-up table of the status word; the T-segment is used to control a time interval between the axis displacements; the status word is used to specify a coordinate axis of the linkage;

The data flow controller includes a microprocessor, an interpreter memory, a file memory, an axis linkage table allocation module, a DRC NC program execution module, a real-time control module, and an interrupt management module; the interpreter memory is configured to store the status instruction The switch instruction, an interpreter of the track instruction; the file memory is configured to receive and store the DRC numerical control program, the follow-up table, and the axis linkage table through the serial interface; a linkage table allocation module is configured to allocate the axis linkage table to the servo driving device through the distribution interface; the DRC numerical control program running module is configured to run the DRC numerical control program, execute the state instruction control auxiliary process, and execute The switching instruction controls the I/O device through the I/O interface, and executes the track instruction to control the machining process of the tool path by the servo interface through the linkage interface; the real-time control module is used to According to the control rhythm Δ t _i (i = 1, ..., n) in the follow-up table, the servo drive is mounted through the linkage interface Sending a linkage command; the linkage command is used to control synchronization between coordinate axes specified by the status word; the interrupt management module is configured to process real-time feedback information from the servo drive device;

The servo drive device is provided with an axis linkage table initialization module and an axis linkage table control module; the axis linkage table initialization The module is configured to set an execution flag, and write an address of the axis linkage table to the L pointer according to the sequence code of the track instruction; following the linkage command, the axis linkage table control module is from the axis according to the L pointer The coordinate value increment of the axis is read in the linkage table and written into the position loop, and the drive coordinate axis feed generates a composite displacement.

Further, in the reconfigurable numerical control system, the number of bytes of the status word is a user parameter.

The axis linkage table file further includes a feature table; the feature table is used to identify a logical attribute of the coordinate axis; the logical attribute includes a feed equivalent, a number of bytes of data, and an electronic gear ratio.

Each data bit of the linkage interface is respectively connected to a servo drive device.

The serial interface and the The distribution interfaces are fieldbus, RS232 interface, RS485 interface, USB interface or wireless interface.

The file storage in the data flow controller further includes a follower table file analysis module; the follower table file The analysis module is configured to read the DRC numerical control program, the follow-up table, and the axis linkage table.

Further, in the above reconfigurable numerical control system, the data flow controller The DRC program running module includes a motion instruction fetching module, a state instruction execution module, a switch instruction execution module, and a track instruction execution module; and the motion instruction fetching module is configured to write an address of the motion instruction in the DRC NC program into the motion instruction Pointer and read motion instructions, Writing a function byte of the motion instruction to the motion instruction register; if the motion instruction is a state instruction, according to the address table of the motion instruction, the state instruction execution module jumps to an entry address specified by the address table, Used for Executing an interpreter of the status instruction; if the motion instruction is a switch instruction, the switch instruction execution module jumps to an entry address specified by the address table according to an address table of the switch instruction, Executing an interpreter of the switching instruction; if the motion instruction is a trajectory instruction, the trajectory instruction execution module is configured to execute an interpreter of the trajectory instruction.

Further, in the reconfigurable numerical control system, the track instruction execution module sets an operation flag for starting the real-time control module; the real-time control module includes a linkage coordinate axis setting module, a linkage command setting module, and a rhythm control module. And an end point control module; the linkage coordinate axis setting module is configured to write the address of the follow-up table to the T pointer, read the status word from the follow-up table and write the status word register, and specify the coordinate axis of the linkage; The linkage command setting module is configured to read Δt _i (i = 1, . . . , n) in the following table and write to the T-split timer; the timing time in the T-segment timer is up, the rhythm control The module start pulse generator outputs a pulse and sends a linkage command to the servo drive device specified by the status word register through a linkage interface; the end point control module is configured to control an end point of the track instruction if the T pointer is equal to The last address of the follower table is closed, and the run flag is turned off; otherwise, the T pointer points to the next time increment Δ t _i .

The reconstruction method of a reconfigurable numerical control system proposed by the present invention comprises the following steps:

Step (1), reconstructing a discrete coordinate system: the digital control information generating component reconstructs a discrete coordinate system; the discrete coordinate system includes an orthogonal discrete coordinate system and a non-orthogonal discrete coordinate system;

Step (2): reconstructing a structure constant database: the digital control information generating component reconstructs a structure constant database; the structure constant database stores a fine structure constant of the coordinate axis and a coordinate system parameter; the fine structure constant of the coordinate axis includes a line displacement Error, angular displacement error, backlash; the coordinate system parameters include non-parallelism and non-perpendicularity between the coordinate axes;

Step (3), construction state Reconstruction of instruction Instruction: Digital control information generation component constructs the state instruction reconstruction instruction ;

Step (4), construction switch instruction reconstruction instruction: digital control information generation component constructs reconstruction instruction of the switch instruction ;

Step (5), running a reconfiguration instruction: the digital control information transmitting component runs the state instruction Reconfiguring the instruction, reconstructing the state instruction, executing a reconstruction instruction of the switch instruction, and reconstructing the switch instruction.

Further, the step (3) in the reconstruction method of the reconfigurable numerical control system includes the following steps:

Step (31), setting a target address parameter of the reconstruction instruction: setting an entry address in the address table of the state instruction as a target address parameter of the reconstruction instruction;

Step (32): setting a source address parameter of the refactoring instruction: setting a starting address of the rewritten interpreter as a source address parameter of the refactoring instruction;

Step (33), setting a byte number parameter of the refactoring instruction: setting a capacity of the rewritten interpreter to a byte number parameter;

Step (34): Constructing a reconstruction instruction: constructing a reconstruction instruction of the state instruction according to the target address parameter, the source address parameter, and the byte number parameter.

Further, the step (4) in the reconstruction method of the reconfigurable numerical control system includes the following steps:

Step (41), setting a target address parameter of the reconstruction instruction: placing the switch The entry address in the address table of the instruction is set as the target address parameter of the reconstruction instruction;

Step (42): setting a source address parameter of the refactoring instruction: setting a starting address of the rewritten interpreter as a source address parameter of the refactoring instruction;

Step (43), setting a byte number parameter of the refactoring instruction: setting a capacity of the rewritten interpreter to a byte number parameter;

Step (44): Constructing a reconstruction instruction: constructing a reconstruction instruction of the switch instruction according to the target address parameter, the source address parameter, and the byte number parameter.

Compared with the prior art, the original beneficial effects produced by the present invention are:

1. Process model based on control flow

Based on the IEEE-defined existing open CNC system object-oriented, the finite state machine processing data model is used to describe complex control tasks with different levels of real-time requirements. The finite state machine is a highly abstract modeling tool for reactive systems. For developers, the structure is complex and the reusability is poor. For the user, it is like a spider web maze, and there is no openness.

Data flow association control is not object-oriented, but process-oriented.

According to the process characteristics of digital control, the present invention proposes a processing data model for an open numerical control system.

Compared with the existing finite state machine model, this processing data model is open, which clearly describes the architecture of the open CNC system and reveals the technical solutions and key technologies for rationally configuring control resources in different control processes.

2. Major changes in digital control methods

In the existing open CNC system based on IEEE definition, the interpolation cycle of the real-time operating system and the communication cycle of the field bus are two system clocks. Following the cycle of the interpolation cycle and the communication cycle, the digital control information of the toolpath curve is continuously generated, distributed, transmitted, and executed, so that the real-time iteration of the digital control information and the real-time iteration of the control process are repeated. In this architecture, the real-time control process of the toolpath curve includes both real-time iteration of the digital control information and real-time iteration of the control process, as well as real-time communication processes, including the accuracy and speed of the interpolation iterative algorithm, and the geometry of the toolpath curve. Characteristics, process characteristics of the process, mechanical systems A series of complex factors such as kinematics/dynamics, processor bits and operating speeds, and other software platforms such as real-time operating systems.

The present invention configures control resources in accordance with a control flow for generating, distributing, transmitting, and executing digital control information. The invention realizes the process and the distribution process of the digital control information in a non-real time, and the real-time control process of the tool path curve is simplified to start the real-time control module according to the rhythm specified by Δ t _i (i = 1,..., n) in the follow-up table. The linkage command is sent to the servo drive device specified by the status word through the linkage interface in one direction; the servo drive device follows the linkage command, and the coordinate value increments in the axis linkage table are successively written into the position loop, and the corresponding coordinate axes are driven to generate the linkage. Synthetic displacement.

The invention replaces the interpolation period with the rhythm Δ t _i (i = 1,..., n) in the follow-up table, and cancels the control right of the real-time operating system to the real-time control process, with the simplest one-way transmission of the linkage command It replaces the extremely complicated real-time communication and eliminates the control of the real-time control process of the fieldbus, thus transforming the real-time control process of the toolpath curve into the real-time transmission of the simplest linkage command, completely eliminating the real-time operation of the operating system and the fieldbus. The control process constraints, the real-time control method and the openness of the real-time control process, leading to major changes in the digital control method.

3, high-precision multi-axis synchronization mechanism

Multi-axis synchronous drive technology is a key technology to be solved in the existing numerical control technology. The national 'high-end CNC machine tools and basic manufacturing equipment' 2009 Science and Technology Major Project '18 full-digital high-end numerical control device' listed the dual-axis synchronous drive technology as a key technology in the existing CNC technology.

In an open CNC system based on IEEE definition, multi-axis synchronization depends on the real-time synchronization mechanism of periodic communication in the fieldbus.

Simple is beautiful.

In the present invention, the multi-axis synchronization depends on the linkage command transmitted in real time through the linkage interface, and the linkage The axes are specified by the status word. The linkage command is a parallel synchronization pulse, the status word is a user parameter, and the linkage interface is similar to a parallel interface under the control of a status word. therefore, The invention solves the multi-axis synchronization mechanism problem with extremely simple technical means, and has the high-speed and high-precision synchronization capability, thereby converting the complex multi-axis synchronous drive technology into a simple conventional technology.

4, reconfigurability

The reconstruction of the mechanical system means the change of the motion relationship of the coordinate axes and the increase and decrease of the coordinate axes, especially the increase of the coordinate axes. Therefore, the reconfigurability of the real-time control process of the tool path curve becomes the core problem of the reconfigurable computer digital control system, which requires the real-time control method to be completely software-based, and the real-time control process is independent of the software platforms such as the operating system and the field bus. Independent of the programming interface.

The existing open CNC system based on IEEE defines object-oriented rather than process-oriented, and the real-time control process of the tool path curve cannot be opened and has no reconfigurability. For different curve types, special interpolation instructions must be defined and configured The real-time interpolation control module is defined, and therefore, the interpolation instructions under the G code standard are not reconfigurable. Corresponding to the movement of the coordinate axis The prior art based on the IEEE definition can only be to add a real-time interpolation control module or modify an existing real-time interpolation control module. Obviously, this is far from the connotation of reconfigurability. Corresponding to the increase of the coordinate axes, especially the reconstruction of mechanical systems corresponding to 5 axes and 5 axes or more, the prior art based on IEEE can only resort to 64 or more bits. High-speed CPU, 64-bit or more A more real-time real-time operating system, more optimized real-time scheduling capabilities, and more advanced interpolation iterative control algorithms, and the need to redevelop that large and complex interrupt system. Obviously, this is not a refactoring problem.

The trajectory command in the present invention has unity, regardless of the type of curve in the tool path curve. There is no refactoring problem.

In the present invention, the DRC numerical control program, the axis linkage table, the follower table and the like manufactured by the PC system include the control. All digital control information required by the servo drive and the I/O device, the digital control information is open, and the method of manufacturing the digital control information is open; in addition, the present invention also de-realizes the digital control information distribution process, and the number is The real-time transmission of control information translates into real-time transmission of extremely simple linkage commands, and the digital control information distribution process is also open.

Corresponding to the increase in the coordinate axis, only the number of bits and the number of bytes of the status word are involved in the present invention. As a user parameter, the number of bits and the number of bytes of the status word are not There is a refactoring problem.

In the present invention The real-time control process of the toolpath curve is simplified to start the real-time control module. The real-time control module is open, through the built-in solidified follower file analysis module, its operation is independent of the operating system of the PC, and there is no need to configure any embedded real-time operating system.

The invention has neither an interpolation cycle nor a communication cycle, and fully realizes the softwareization of the real-time control method, completely solving the reconstruction problem of the real-time control process of the toolpath curve.

Corresponding to the reconstruction of the mechanical system, it also involves the auxiliary function operation and the switching control in the I/O device. This relates to the status command and the switch command in the present invention.

State commands and switch commands are associated with the mechanical system The specific structure is inseparable and belongs to the personalization function. After the mechanical system is reconfigured, state commands and switching instructions often need to be reconstructed. The present invention sets a reconstruction instruction for rewriting an interpreter of a state instruction and a switch instruction. write The interpretation of the status and switch instructions is a simple conventional technique.

The reconstruction of the digital control system also involves the reconstruction of the internal interface, especially the reconstruction of the motion control level real-time interface. The invention divides the motion control interface into a non-real time serial interface and a real-time linkage interface.

The linkage interface of the present invention is not a communication interface, and the linkage command is only a synchronization pulse. At the transmitting end, the linkage interface similarly transmits the parallel interface of the status word unidirectionally according to the rhythm specified by Δt _i (i = 1,..., n); at the receiving end, one servo drive device and one data of the linkage interface respectively Bit connection, the linkage interface is similar to an interrupt control line. Therefore, the linkage interface proposed by the present invention does not have a reconstruction problem.

The non-real time interface of the present invention is a standard serial interface such as a standard USB interface or other standard serial interface supported by the UART. , is a conventional technology. The non-real time interface does not need to be reconstructed.

In the present invention, the PC system, the data flow controller, and the motion control interface are independent of the software platform such as the operating system, and are also independent of the hardware platform. Thus, the reconfigurable numerical control system proposed by the present invention has platform independence.

The reconstruction of the CNC system also involves a programming interface. In the existing open CNC system based on IEEE definition, the NC machining program in the form of G code must be carried out under the control of the real-time operating system, thus being related to the software and hardware platform. As a programming interface, the G code standard does not have the consistency of the human machine interface. In the present invention, the DRC numerical control program is adopted The standardized file system replaces the G code program, has the consistency of human-machine interface, and there is no reconstruction problem.

Therefore, in the present invention, the reconstruction of the numerical control system involves only the reconstruction of the discrete coordinate system and the structure constant database. Refactoring. Based on the architecture proposed by the present invention, the above problems basically belong to the conventional techniques in the existing IT technology.

In summary, the reconfigurable numerical control system proposed by the present invention has good reconfigurability.

5, standardized control machine

1), standardization of the architecture

The architecture of the reconfigurable numerical control system proposed by the present invention configures control resources based on a control flow of generation, distribution, transmission, and execution of digital control information. In particular, the present invention distributes information in digital control In the process, the axis linkage table is distributed to the servo drive device through the non-real-time serial interface, so that the digital control information distribution process is not real-time, which significantly simplifies the architecture of the reconfigurable numerical control system.

In the reconfigurable numerical control system proposed by the present invention, the digital control information generating unit is a standardized component based on the PC. DRC numerical control program, axis linkage table, follower table, etc. manufactured by digital control information generating unit Digital control information files are standard files and are independent of software platforms such as operating systems. The standardized file system becomes the carrier of digital control information and realizes the openness of digital control information.

The non-real-time implementation of the digital control information distribution process significantly simplifies the function and structure of the data flow controller. As an embedded system, the data flow controller is only used to run the DRC NC program and send the linkage command. It does not need to configure any embedded operating system. When running the DRC NC program, its core function is only to write Δ t _i into the T split timing. In the state word control, the linkage command is sent in real time through the linkage interface, and the function and structure are extremely simple and can be standardized.

2) Standardization of motion control interface

The standardization of CNC systems also involves the standardization of internal interfaces, especially the standardization of real-time interfaces at the motion control level.

In the existing open CNC system based on IEEE definition, in order to realize real-time allocation of coordinate value increments, fieldbus technology has become the mainstream technology of motion control interface between CNC system and servo drive device. The fieldbus technology is based on the ISO/OSI open system interconnection reference model, completely ignoring the process characteristics of digital control, completely ignoring the essential characteristics of the numerical control device different from the computer network. The communication cycle becomes the system clock, and the data link layer and the application layer and its protocol real-time, data representation compatibility and other issues consume a lot of computing resources.

There are as many as 12 international standards for fieldbus, and there are more enterprise standards for manufacturers. This situation leads to the Chinese national standard 'GB/T 18759.2-2006•Mechanical and electrical equipment • Open CNC systems • Part 2 Architecture' 5.6 models have been set up to support various fieldbuses (eg CAN, Profibus, Sercos, etc.).

Unfortunately, multiple standards mean no standards.

The invention divides the motion control interface into a non-real time serial interface and a real-time linkage interface. In the auxiliary process, each axis The axis linkage table is assigned to the corresponding servo drive via the serial interface. In the serial interface, the communication cycle is not a system parameter, and there is no synchronization mechanism, which avoids the real-time performance of the communication protocol and other complicated problems. Said The axis linkage table is a standard file, and there is no compatibility problem with the data representation. Thus, the serial interface can be any Standard serial interface, such as a standard USB interface or other standard serial interface supported by the UART.

The linkage command is just a sync pulse. At the transmitting end, the linkage interface similarly transmits the parallel interface of the status word in a one-way manner according to the rhythm of Δt _i (i = 1,..., n); at the receiving end, one servo drive device is respectively connected with one data bit of the linkage interface The linkage interface is similar to an interrupt control line. Obviously, the linkage interface can be standardized.

Therefore, the linkage interface and the non-serial interface are standardized, and the standardization problem of the motion control interface is solved.

3), standardization of programming interfaces

In the existing open CNC system based on IEEE definition, the G code standard is adopted as the programming interface of the numerical control machining program. When the paper tape was used as the basic physical medium for input in the 1950s, the code standard for the paper tape perforation, that is, the G code standard, was established for the specification of characters on the paper tape.

In the G code program, different interpolation commands are used to describe different curves in a tool path curve. For different curves, different interpolation iteration algorithms must be used to implement different interpolation instructions. The real-time processing of the curve is real-time by the interpolation iterative algorithm, which leads to the interpolation iterative algorithm becoming an object-oriented closed real-time control algorithm. The openness and reconfigurability of the digital control system are restricted from the real-time control process.

G The code standard is the original product of the initial stage of information technology. Due to the limitation of the paper tape, there is inevitably a defect that the amount of information is too small. Therefore, each manufacturer has extended the basic semantics of the G code, resulting in the dependence of the G code program and the corresponding hardware. The NC machining program is not interchangeable between different CNC systems, and does not have the consistency of the human-machine interface. The various CNC systems are incompatible with each other, hindering the exchange and sharing of control information, and restricting the openness and reconfigurability of the digital control system from the programming interface.

In the interpolation iteration algorithm, each axis must have the same logical attribute . Once the logical attributes of the coordinate axes are different, for example, the feed equivalents (nano, micro, etc.) are different, the number of bytes of data is different, etc., the functions and structures of the numerical control system must be changed accordingly, from real-time control process and real-time communication. The two aspects of the process restrict the openness and reconfigurability of the system.

In the reconfigurable numerical control system proposed by the present invention, according to the order determined by the processing process, the state command, the switch command, the track command are used to write DRC NC program.

The DRC NC program is oriented to the control process, and the path command is oriented to the machining process of the tool path curve. Track command axis linkage table and follower table All of the digital control information required to machine the toolpath curve is created non-real-time by the digital control information generation component, thus allowing each axis to have different logic properties.

The above DRC NC program, axis linkage table, and follower table are standardized The form of the file is transferred in the system and also transferred between different CNC systems in the form of files.

The above documents conform to the file specification and use file systems such as FAT16 and FAT32. Standardized documents become The carrier of digital control information has nothing to do with the hardware platform, and has nothing to do with the software platform such as the operating system. It has extensive platform independence and realizes the openness of digital control information. The above DRC numerical control program, axis linkage table and follower table are adopted. The standardized file system realizes the standardization of control information and becomes an easy-to-standardized programming interface.

In summary, the reconfigurable numerical control system proposed by the present invention realizes the openness of digital control information, the openness of the digital control method, the process of generating digital control information, the process of distribution, the process of sending, and the openness of the execution process. It has laid a solid foundation for the standardization of CNC systems.

6, universal and efficient open CNC language

Compared with the existing G code numerical control language, the state instruction, the switching instruction, the trajectory instruction and the DRC numerical control program proposed by the invention Work-oriented machine, simple logic structure, consistency of human-machine interface, PC-based and no need to compile, is an open, universal and efficient CNC technology The motion description language and the logic description language fully support the user's own application of CNC technology and always maintain the consistency of the human-machine interface.

7, high reliability

It is well known that in the existing open CNC system based on IEEE definition, the interpolation cycle and the communication cycle are two system parameters, which not only consume a large amount of computing resources, but also generate, distribute, transmit, and execute digital control information. The real-time control process leads to real-time operating system and fieldbus becoming two key links that restrict the reliability of the CNC system.

The operating system is an extremely complex system that may contain hundreds of thousands of potential vulnerabilities. These vulnerabilities often take years, ten years of maintenance time to fix, and are difficult to completely eliminate. Statistics show that the factors that affect the reliability of computer systems, hardware errors only account for a few percent, the vast majority of errors stem from system management. Obviously, system management errors are basically derived from the operating system. Therefore, for the reliability of computer numerical control systems, the real-time operating system is like the sword of Damocles.

The communication process is exposed to harsh industrial environments. In the existing open CNC system based on IEEE definition, the fieldbus causes the communication cycle to become a system parameter, and the communication protocol has real-time performance and data representation compatibility. Internal communication is highly complex and is another important reason for reliability.

In the present invention, the PC does not intervene in the real-time control process of the toolpath curve, and the operation of the data flow controller is independent of the operating system of the PC, and there is no need to configure any embedded real-time operating system.

The invention separates the digital control information distribution process from the real-time control process of digital control information The process of assigning digital control information is completed in one communication process, and the communication cycle is no longer a system parameter. In particular, in contrast to the real-time periodic communication process in the field bus, the linkage in the present invention The interface simply transmits the sync pulse in one direction, and the function and structure are highly simplified.

In summary, the present invention solves two key links that restrict the reliability of the numerical control system from the source, and has high reliability.

8, intelligent open platform and reconfigurable production line

Existing G code programming interface does not have the consistency of human-machine interface, CNC programming has to rely on the CNC system manufacturer to provide Programming instructions. Therefore, the user has to train a specific programmer for a specific CNC system. CNC programming can only be attached to the production workshop as a process, and cannot be transformed into a social industry across the enterprise.

Similarly, In the existing open CNC system based on IEEE definition, the real-time control process of the tool path curve cannot be opened. For different tool path curves, such as arc, parabola, involute, NURBS curve, etc., the corresponding interpolation iterative algorithm must be developed and the corresponding real-time control module should be configured in the numerical control application software. The real-time control process of the tool path curve is also related to the field bus. It needs to deal with a series of complicated problems such as communication cycle, real-time communication protocol and data representation compatibility. Therefore, the development of numerical control technology is also scattered among different CNC system manufacturers, and cannot be transformed into a social industry across enterprises.

In the present invention, the PC system generates a DRC numerical control program, It becomes an open platform for NC programming; the PC system generates the axis linkage table and the follower table of the tool path curve, and becomes an open development platform for numerical control technology. The present invention adopts a standard file system such as FAT16, FAT32, etc. The programming interface, the DRC NC program, thus becomes a fully digital, commercial 'digital control information' product manufactured by digital control information generation components. The PC system can receive this through the Internet. Commercialized 'digital control information' is transmitted to the data flow controller.

The invention integrates numerical control programming and numerical control technology development, transforms workshop production into social production, and thus evolves into A social industry, namely digital control information manufacturing, the PC system, ie digital control information generation component, becomes an intelligent open platform for manufacturing digital control information.

In the present invention, a PC is used as a manufacturing digital control information The intelligent open platform can serve multiple CNC equipment. Data flow controller as an embedded system, no need to configure any embedded The operating system, function and structure are extremely simple, highly reliable, can be independently configured in the CNC device, and completely independent of the PC system.

For a reconfigurable production line consisting of multiple CNC machine tools, digital fixtures, handling robots, etc., the reconfigurable numerical control system proposed by the present invention adopts a split architecture, which has high reliability, simple structure, low price, and easy integration. advantage.

9. The control machine that was expected in the third industrial revolution

In a general sense, the architecture of modern manufacturing equipment can be abstracted into three systems, namely, power, work and control. The power machine provides energy, and the control machine sends control information to the working machine and the power machine, and the working machine obtains energy from the power machine to complete the manufacture of the product.

The symbol of the first industrial revolution was the birth of a working machine, which replaced mechanical tools.

The symbol of the second industrial revolution was the birth of the power machine. The steam engine, internal combustion engine and electric motor replaced human and animal power.

The third industrial revolution will be based on automation, the birth of the control machine.

From the manufacturing point of view, the above division is logical.

In manufacturing, digital control systems act as control planes. However, existing digital controls The system has serious flaws in terms of openness, reconfigurability, standardization, and software control of digital control technology. It is not comparable to power machines and work machines, and it is difficult to become the control machine that the third industrial revolution expects.

Compared with the existing open CNC system based on IEEE definition, the reconfigurable numerical control system proposed by the invention has the openness of digital control information, the openness of the digital control method, the generation process of the digital control information, the distribution process, and the transmission process. The full openness of the execution process and the openness of the internal communication interface.

Compared with the existing open CNC system based on IEEE definition, the reconfigurable numerical control system proposed by the invention has a highly simplified real-time control process and digital control method, and the digital control technology is completely software-based, highly reliable, can be standardized, and the price Significant advantages such as low cost and easy to popularize. Therefore, as a PC-based, all-round open, reconfigurable, standardized open CNC system, the reconfigurable numerical control system proposed by the present invention is the control machine expected by the third industrial revolution.

附图说明 DRAWINGS

Figure 1 is a schematic diagram of the process model based on the control flow;

Figure 2 is a second diagram of the process model based on the control flow;

3 is a schematic structural diagram of a numerical control system in a specific implementation manner;

4 is a functional block diagram of the PC system of FIG. 1;

Figure 5 is a functional block diagram of the data flow controller of Figure 1;

Fig. 6 is a functional block diagram of the servo drive device of Fig. 1.

具体实施方式 detailed description

The invention provides a reconfigurable numerical control system, from the architecture of the digital control system, the control method of the real-time process and the non-real-time process, the structure and programming interface of the DRC numerical control program, the function and structure of the internal communication interface, and the servo drive device. The DRC control machine is further improved in terms of function and structure to meet the requirements of the third industrial revolution for the reconfigurable numerical control system.

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

In order to ensure that the machine structure and its layout can be quickly reorganized according to the changes of the processed products, the modular structure becomes the basic technical feature of the reconfigurable machine tool. Often, the concept of modularity and its implementation are limited to machine tool builders. However, in reconfigurable machine tools, the concept of modularity and its implementation must extend to the user, in other words, the user-oriented nature of reconfigurability.

In reconfigurable machine tools, the so-called reconfigurability refers to the ability of the user to quickly reorganize the structure, layout, and machining functions of the machine tool according to the changes in the processed product.

Reconfigurable CNC systems are also generally considered to be modular in relation to the modularity of reconfigurable machine tools.

The core function of the digital control system is to control the machining process of the toolpath curve in real time. This means that for reconfigurable CNC systems, the tool path curve The real-time control process must be open and user-oriented.

It has been explained in the background art that in the existing open CNC system based on IEEE definition, the real-time control process of the tool path cannot be opened. The reason is that, on the one hand, the numerical control application for the real-time control process The software system becomes a large and complex interrupt system using parallel algorithms, multi-process/multi-threaded nested calls, and multiple real-time nested interrupts under the control of the real-time operating system. On the other hand, the real-time control process of the tool path curve and the geometric characteristics of the tool path curve, the process characteristics of the machining process, and the mechanical system The kinematics/kinetics are inseparable, and are inseparable from the hardware platforms such as the number of bits of the CPU and the speed of operation. They are inseparable from software platforms such as real-time operating systems, and are inseparable from the interpolation iterative algorithm.

Therefore, in the existing open CNC system based on IEEE definition, the so-called real-time control modular structure is essentially an object-oriented modular structure, that is, different real-time control modules are configured for different toolpath curves. Unfortunately, this object-oriented modular structure is not user-oriented, but is aimed at CNC manufacturing companies, and runs counter to the essential features of reconfigurability. Thus, relying on this object-oriented modular structure to achieve reconfigurability of a digital control system is only an illusion.

Man and machine tools are the two service objects of the digital control system, and there must be information exchange between the three. It has been explained in the background art that in the existing open CNC system based on IEEE definition, the G code standard is used as the programming interface on the human-machine interface, and the field bus is adopted in the motion control level, thereby causing the programming interface and the field bus to be based on The existing open CNC system defined by IEEE has no important factors for reconfigurability.

Based on the above analysis, the inventor defined the reconfigurable numerical control system as:

The so-called reconfigurable numerical control system is a numerical control system that configures the embedded subsystem according to the control flow. It has software control of real-time control methods, real-time control process and the independence of hardware platforms such as processor digits and speed, and software platforms such as operating systems. Independence, and independence from the programming interface.

Data Flow Association Control Configure control resources according to the process of manufacturing digital control information. DRC NC program It is a fully digital and commercial 'digital control information' product manufactured by digital control information generating components. The digital control information generating component is both an open platform for numerical control programming and an open type for numerical control technology. Development platform, real-time control method is completely software.

In the architecture of the existing open CNC system, the servo drive device is regarded as a functional component of the CNC machine tool and does not belong to the category of the CNC system. according to The above definition of the reconfigurable numerical control system, the present invention further improves the DRC from the aspects of control flow, architecture, field bus, programming interface, etc. Control machine. These problems require the servo drive to be incorporated into the CNC system to re-examine the function and structure of the servo drive.

In the digital control of the machine tool, the servo drive includes a servo motor and its motion control system, which is mainly used to control the speed and rotation angle of the servo motor. . The so-called speed control is also called speed mode, which is the speed control, which is used to control the speed of the spindle. The so-called corner control is also called the position mode. That is, position control is used to control the displacement of the coordinate axes. In the present invention, the servo drive is in a position mode, the number of which is received and executed The control information is discrete position information of the coordinate axes, and the position feedback information is processed by the embedded system in the servo drive. As for the speed of the spindle, it is regarded as a process parameter, which is attributed to the switch quantity control with parameters.

It can be seen from the background art that in the data flow association control, the core task of the digital control technology is to generate a linkage table and a follower table of the tool path curve. The so-called real-time control process is based on the control rhythm in the follow-up table, the distribution process of the coordinate value increment, the sending process, and the execution process.

For example, in order to realize 5-axis linkage of five coordinate axes of X, y, Z, A, B, etc., first read Δ X ₁ , Δ y ₁ , Δ Z ₁ , Δ A ₁ , Δ B ₁ from the linkage table and It is sent to X, y, Z, A, B and other servo drive devices through the motion control interface; X, y, Z, A, B and other servo drive devices receive △ X ₁ , △ y ₁ , △ Z ₁ , △ A ₁ After △ B ₁ , write its position loop and drive the 5-axis linkage of X, y, Z, A, B, etc. to realize the combined displacement Δ L ₁ ; after Δ t ₁ , read △ X ₂ from the linkage table. △ y ₂ , △ Z ₂ , △ A ₂ , △ B ₂ are respectively sent to the servo drive devices such as X, y, Z, A, B through the motion control interface; servo drives such as X, y, Z, A, B, etc. After receiving △ X ₂ , Δ y ₂ , △ Z ₂ , △ A ₂ , △ B ₂ , the device writes its position loop and drives 5-axis linkage of X, y, Z, A, B, etc. to realize the combined displacement Δ L ₂ This cycle is repeated to produce the resultant displacement required by the tool path curve according to the control rhythm until the end of the tool path curve.

The linkage table and the follower table are referred to as associated data streams of the toolpath curve and are generated by the digital control information generating component.

L segmentation in the linkage table

Δ L _i ( Δ X _i , Δ y _i , Δ Z _i , Δ A _i , Δ B _i ), i = 1,..., n,

It is possible to separate into five sub-tables by Δ X _i , Δ y _i , Δ Z _i , Δ A _i , and Δ B _i , which are referred to as an axis linkage table of the tool path curve. If the 5-axis axis linkage table of X, y, Z, A, B, etc. is assigned to the servo drive units such as X, y, Z, A, B in the auxiliary process, the digital control information distribution transmission process can be separated into digital control information. The distribution process and the digital control information transmission process, so that the digital control information distribution process is not real-time, and is separated from the real-time control process of the digital control information.

In this way, for the 5-axis linkage of the X, y, Z, A, B and so on, the real-time control process is that the servo drive devices such as X, y, Z, A, B, etc. follow the control rhythm in the follower table. Δ t _i (i = 1,..., n), from Δ X _i (i = 1,..., n), Δ y _i (i = 1,..., n), Δ Z _i (i = 1,..., n), Δ A _i (i = 1,..., n), △ B _i (i = 1,..., n), etc. The coordinate value increments are read synchronously in real time in five axis linkage tables and executed.

The non-real-time implementation of the digital control information distribution process leads to important improvements in the following four areas.

1), process model and architecture

Document "open CNC technology and its development in our country" ( "Aeronautical Manufacturing Technology" 2010 three authors: Acer-rich Liang Quan pointed out that the openness of CNC systems can be divided into three categories: the openness of CNC system software, the openness of the processing data model and the openness of the hardware implementation platform.

The machining data model of the CNC system is the basis for planning the architecture and developing the CNC technology.

Based on the IEEE-defined existing open CNC system object-oriented, the processing data model is used to describe the function, behavior, starting process, and the relationship between each object in the numerical control system, especially for complex, Multiple control tasks required by different levels of real-time requirements are clearly described. Thus, using a finite state machine (Finite The machining data model of State Machine, FSM) plays an important role in the development of open CNC systems. For example, the Chinese national standard "GB/T 18759. 1-2002 • Mechanical and electrical equipment • Open CNC system • Part 1 General, GB/T 18759.2-2006 • Mechanical electrical equipment • Open CNC system • 2nd Part: Architecture" clearly defines the finite state machine model. The finite state machine is a highly abstract modeling tool for reactive systems. For developers, the structure is complex and the reusability is poor. For the user, it is like a spider web maze, and there is no openness.

Data flow association control is not object-oriented, but process-oriented. It is necessary to propose an open processing model for open CNC systems based on the process characteristics of digital control.

The invention divides the control flow into four parts: a digital control information generation process, a digital control information distribution process, a digital control information transmission process, and a digital control information execution process. The process, in turn, separates the digital control information distribution process from the real-time control process of digital control information into a non-real-time process.

After the digital control information distribution process is separated from the real-time control process of the digital control information, the architecture of the digital control system is decoupled into a digital The control information generating unit, the digital control information distributing unit, the digital control information transmitting unit, and the digital control information executing unit have four functional components. The digital control information execution unit includes a servo drive device and an I/O device.

The control process can be divided into a real-time process and a non-real-time process. From the perspective of reconfigurability, the functions and structures of the four functional components should Re-examination, the real-time process and the control method of the non-real-time process should be re-examined.

2), file structure

The digital control information distribution process is separated from the real-time control process of the digital control information, and is used as the structure of the DRC NC program for numerical control machining. It should be revisited from the perspective of reconfigurability to support the real-time control process and the non-real-time allocation process.

3), programming interface

The program interface refers to a programming interface between machining programs when different machining systems are exchanged between different numerical control systems.

Between different CNC systems, the DRC NC program becomes the programming interface. Digital control information distribution process from digital control information After separation in the real-time control process, the file becomes the carrier of digital control information in the control flow. Therefore, the DRC NC program file Not related to the operating system platform. However, from the perspective of reconfigurability, the DRC NC program should be independent of the fieldbus as a programming interface.

4), internal interface

The digital control information distribution process is separated from the real-time control process of the digital control information, and the axis linkage table Non-real-time allocation to the servo drive, the real-time control process is highly simplified, the real-time communication process of the internal interface is highly simplified, and the function and structure of the internal interface should be Re-examine to support the reconfigurability of the real-time communication process.

The invention provides a reconfigurable numerical control system, from an open architecture of a numerical control system, a control method of a real-time process and a non-real-time process, a structure and a programming interface of a DRC numerical control program, a function and structure of an internal interface, and a servo drive device. The DRC control machine is further improved in terms of function and structure to meet the requirements of the third industrial revolution for the reconfigurable numerical control system.

The machining process of the workpiece can generally be divided into auxiliary process, tool change process and tool pass process.

The auxiliary process involves auxiliary functions and status settings controlled by the I/O device.

The tool change process involves tool magazine control. For the tool change process, the conventional PLC is used to control the tool magazine, or the soft PLC is used to generate the control flow of the combination logic to control the tool change process. The control methods of the existing PLC and I/O devices are not discussed or changed in this embodiment.

The pass process involves real-time control of the tool path curve.

Therefore, in the machining process of the workpiece, the numerical control system has only three working states: auxiliary function operation, switch quantity control, and real-time control of the tool path curve. Data Flow Association The control uses the three types of motion commands: state command, switch command, and track command to describe these three operating states.

First, the motion instruction

1), status command and auxiliary function operation

Status instructions are used to describe auxiliary functions.

Status instructions can be divided into system initialization status instructions and system operation status instructions.

The system initialization status command is used to set/modify some parameters, such as setting the initialization parameters of the servo drive, initialization parameters of the tool magazine, and so on. The system running status command is used to set the running status of the system. For example, set the running status of automatic, manual, specified block, start, end, pause, etc., realize the functions of detection, parameter adjustment, fault diagnosis, etc., and modify the switch command and status command. Interpreter and so on.

Status instructions include function bytes, auxiliary bytes.

(1), function byte

The function byte is 2 bytes and is used to describe the basic functions of the status instruction, including the identification code and the instruction code.

The first function byte is the identification of the status instruction.

B ₇ : identification of a status command or a switch command, for example, B ₇ = 1;

B ₆ : identification code of the status instruction, for example, B ₆ = 0;

B ₅ : parameter status of the identification status command with or without parameters;

B ₄ ~ B ₀ : 5-digit signature, the number of identification parameters can carry up to 32 parameters.

The second function byte is the function code of the status instruction, which has a total of 256 status instructions.

(2), auxiliary byte

The auxiliary byte is a number of bytes that identify multiple parameter values for the status instruction, each parameter occupying 2 bytes.

The status command also includes a diagnostic command for assigning a series of specificities to the servo drive. Data to diagnose faults in the linkage table assignment process.

2), real-time control of switching commands and switches

The switch command is used to describe the parameters of the switch and its control.

The present invention is considered to be a virtual coordinate axis if the switch carries process parameters that require real-time control.

The switch is a conventional PLC control if it does not carry process parameters that require real-time control. The spindle speed control can be regarded as a switch carrying parameters (speed).

The tool change command is a regular PLC control. The present invention treats the tool change command as a switch command. As a conventional technique, the present invention does not relate to a tool change command The specific control process.

The switching instructions include function bytes and auxiliary bytes.

(1), function byte

The function byte is 2 bytes and is used to describe the basic functions of the switch instruction, including the identification code and the instruction code.

The first function byte is the identification of the switch instruction.

B ₇ : identification of a status command or a switch command, for example, B ₇ = 0;

B ₆ : identification code of the switching instruction, for example, B ₆ = 1;

B ₅ : parameter status of the identification switch command with or without parameters;

The second function byte is the function code of the switch command, a total of 256 switch commands.

(2), auxiliary byte

The auxiliary byte is a plurality of bytes, and identifies a plurality of parameter values of the switch instruction, each parameter occupying 2 bytes.

For state commands and switch commands, the present invention configures an address table for storing the entry address of the interpreter of the state command and the switch command. The user (or developer) can define its own auxiliary bytes and define their functions by rewriting the interpreter. Therefore, the instruction format of the status instruction and the instruction format of the switch instruction are both open, supporting the secondary development of the user (or developer).

The state command and the switch command are inseparable from the specific structure of the working machine and belong to the personalization function. This state instruction that rewrites the interpreter is called a refactoring instruction.

3), real-time control of track command and tool path curve

In the DRC control, for a tool path curve, a trajectory command is used to control the servo drive device to achieve coordinate axis linkage.

In the DRC control, the process parameters that need to be controlled in real time are carried by the switch. The switch is called a virtual coordinate axis, and the process parameter is called the coordinate value of the virtual coordinate axis. Therefore, in the present invention, the coordinate axis includes a virtual coordinate axis.

The track instruction is a single-byte instruction whose instruction code is:

B ₇ : identification of the track command, for example, B ₇ = 0;

B ₆ to B ₀ : 7-bit sequential code for numbering the track command.

The address code of the interpreter of the track instruction is the system parameter, which is automatically imported by the system at runtime.

The sequence code establishes a one-to-one correspondence between the trajectory command of the tool path curve and the linkage table and the follower table carried by the sequence code; Used to control the linkage of the relevant coordinate axes to produce the required composite displacement; the follower table is used to control the time interval between the synthetic displacements.

In the present invention, the track command has only one format, regardless of the type of curve in the tool path curve.

Second, DRC NC program

In the course of a pass, the path of the tool center is called the Tool Path.

According to the given data format, the data of the L segmentation ΔX _i , Δ y _i , Δ Z _i , Δ A _i , Δ B _i , Δ W _i , Δ E _i , Δ H _{i of} a tool path curve in the storage space The file is called the L-segment linkage table. According to the given data format, the data segment of the T-segment Δ t _i (i = 1,..., n) of the tool path curve in the storage space is called the T-segment follower table. L-segmentation and T-segmentation are called associated data streams of the toolpath curve.

In the T segmentation, Δ t _i is an unsigned 2-byte binary integer.

In the L segmentation, the coordinate value increments (Δ X _i , Δ y _{i ,} etc.) are signed binary integers represented by the original code, and the highest bit is the sign bit (+/-), which corresponds to the forward/reverse rotation of the coordinate axis. In particular, the feed equivalent (nano or micron) of the coordinate value increments (Δ X _i , Δ y _{i ,} etc.) and the number of bytes occupied by the data may be different.

In the machining process of the workpiece, the numerical control equipment only has the auxiliary function operation and the logic of the I/O device. Three working states, such as control and real-time control of the tool path curve. Therefore, the machining process of the workpiece can be generally divided into an auxiliary process, a tool change process and a pass process. The auxiliary process involves auxiliary function operation, the tool change process involves tool magazine control, and the pass process involves real-time control of the tool path curve.

Corresponding to these three working states, CNC system There are three types of motion commands: state commands, switch commands, and track commands. According to the order determined by the machining process, the user uses the status command, the switch command, and the track command to describe the entire machining process of the workpiece.

The set of motion instructions that are determined by the machining process is the NC machining program of the workpiece machining process, which is referred to as DRC. CNC program.

DRC The numerical control program is a digital product manufactured by a digital control information manufacturing system, thereby completely digitizing the conventional form of control information, such as a paper, a G code program, and the like.

The DRC NC program consists of motion instructions for controlling the machining process of the workpiece; motion commands include status commands, switch commands Trajectory instruction;

Status Command Used to operate the auxiliary function.

The switch command is used to control the I/O device.

The path command is used to control the servo drive to complete the path of a tool path curve.

Third, the structure of the DRC NC program

As a digital product of digital control information, the structure of the DRC NC program is also the digital structure of the product. The structure of the DRC NC program determines the function and structure of the DRC controller. Conversely, the function and structure of the DRC controller affect the structure of the DRC NC program.

The machining of the workpiece generally involves multiple passes. Each pass process completes the machining of a tool path curve.

A tool path curve usually consists of several segments of curves. The geometry of each segment may or may not be the same. The axes of each curve may be the same or different.

The invention does not segment according to the geometry of the curve, but is segmented according to the coordinate axes of the linkage. The coordinate axes of the linkages in each segment are the same and are described by a track command. Therefore, the processing of a tool path often uses multiple track commands.

The sequence code in the track command is used to number the track commands in the order in which they are processed.

In the present invention, the linkage table is divided into an axis linkage table according to the coordinate axes of the linkage. For example, an X-axis linkage table for Δ X _i (i = 1, ..., n), a y-axis linkage table for Δ y _i (i = 1, ..., n), and the like.

The trajectory command corresponds to the axis linkage table and the follower table of the tool path curve.

Set the status word in the follow-up table to identify the segment The coordinate axis of the linkage in the curve. The status word is one byte, and the number of bytes can be 32, 16, or 8. For example, an 8-bit status word can specify 8 The coordinate axes of the linkage. From low to high, each bit of the status word controls the enable state and data channel of a servo drive. For example, the status word '11100000' specifies a servo drive device such as an X, y, or Z axis, and a status drive word '00011000' to designate a servo drive such as A or B.

The number of digits and the number of status words are user parameters. The user can set the number of bits and the number of bytes of the status word through the status command.

Set a feature table in each axis linkage table file to identify the segment The logical properties of the axes in the curve; the logical properties of the axes include the feed equivalent (nano, micro, etc.), the number of bytes occupied by the data, and the servo parameters such as the electronic gear ratio. . Therefore, in one machining process, each coordinate axis is allowed to have different feed equivalents, different data bytes, and different electronic gear ratios to meet the needs of high-speed and high-precision machining.

In order to access files by name, the file directory includes a large amount of information such as file name, physical address, file structure, and access control.

DRC CNC program, axis linkage table, The follower table adopts the standard file format, and the rich information and the large amount of information of the programming interface are difficult to implement by the G code program programming interface.

DRC The NC program is an executable file; the axis linkage table and the follower table are data files. The DRC NC program, the axis linkage table, and the follower table all use standard file systems such as FAT16 and FAT32.

A file system is a method of organizing files on disk. FAT (File Allocation Table) is a widely used standardized file system. In order to realize the massive data storage of the single-chip system and support the single-chip computer system and the computer using the operating system to exchange data through the file system, some file management has been developed. Chips, such as CH376, SL811, PB375A, etc. File Manager has built-in FAT16, FAT32 file system file analysis firmware, used to read the FAT table, FDT table, BPB table and other related sector addresses and data area addresses, without having to configure the operating system, thus independently complete all functions of file management: open, new Or delete files, enumerate and search files, support long file names, and more.

Fourth, the control process

The data flow association control is process oriented, and the control resources are configured in accordance with a control flow for manufacturing digital control information.

The non-real-timeization of the axis linkage table allocation process leads to the separation of the digital control information distribution process from the real-time control process of digital control information. The control process is divided into four sub-processes: digital control information generation process, digital control information distribution process, digital control information transmission process and digital control information execution process. The architecture of the digital control system is decoupled into digital The control information generating unit, the digital control information distributing unit, the digital control information transmitting unit, and the digital control information executing unit have four functional components.

From a real-time perspective, control processes can be divided into real-time processes and non-real-time processes. The digital control information generation process and the digital control information distribution process are non-real-time processes, and the digital control information transmission process and the digital control information execution process are real-time processes.

1), digital control information generation process

The digital control information generation process is the process of manufacturing the associated data flow, that is, the linkage table of the tool path curve and the generation process of the follower table. The digital control information generation process also includes a process of generating a DRC numerical control program, that is, a programming process of the machining process.

The digital control information generation process is a non-real time process.

The digital control information generating component generates a DRC numerical control program, which includes the following contents:

(1) Establish an orthogonal discrete coordinate system/non-orthogonal discrete coordinate system according to the kinematics of the mechanical system;

(2), according to the mechanical system a mechanical property, a structural constant database is created for storing the mechanical property; the mechanical property includes a linear structure error such as a linear displacement error of the coordinate axis, an angular displacement error, a backlash, and a non-parallelism between the coordinate axes, Coordinate system parameters such as non-perpendicularity;

(3) According to the processing technology, plan the tool path curve, complete the tool compensation and tool path planning, and generate the tool path curve file;

(4) Perform discrete geometric programming and discrete motion planning for each tool path curve in the tool path curve file, generate the axis linkage table and the follower table of the tool path curve, and generate corresponding track command and its axis linkage table and Follow-up table;

(5) generating a corresponding status instruction according to the user program;

(6) According to the user program, complete the switch quantity control in the I/O device, and generate a corresponding switch command;

(7) According to the processing technology, link state command, switch command, track command, generate DRC NC program; the last motion command is the 'stop' state command for ending the machining.

2), digital control information distribution process

The digital control information distribution process is to assign an axis linkage table to the servo drive. The assignment control information is in the catalog of the axis linkage table.

By assigning the axis linkage table to the corresponding servo drive in advance, the assignment process of the linkage table is de-realized.

3), digital control information transmission process

The digital control information transmission process and the digital control information execution process involve the operation of the DRC NC program.

DRC The NC program running process is also the execution process of the motion instruction, including reading the motion instruction from the DRC NC program and the interpretation program for executing the motion instruction.

In the fetching process, the function byte of the motion instruction is written into the motion instruction register, and the address of the next motion instruction is written to the motion instruction pointer, and the analysis processing Other bytes; during execution, the instruction of the motion instruction is executed according to the instruction code and the address code, and the function specified by the motion instruction is completed.

If the decoding is determined to be a status instruction, according to the address table of the motion instruction, jump to the entry address specified by the address table, and execute an interpreter of the status instruction;

If the decoding is determined to be a switch instruction, according to the address table of the switch instruction, jump to the entry address specified by the address table, and execute an interpretation program of the switch instruction;

If the decoding is determined to be a track instruction, the interpretation of the track instruction is executed.

The state instruction and the execution of the switch instruction are auxiliary processes, and the requirements for real-time performance are not high, which is a conventional technique.

The execution process of the trajectory command is the pass process, which is a real-time control process of the tool path curve, which is the core function of the CNC system.

The machining of the workpiece generally involves multiple passes. Each pass process completes the machining of a tool path curve. Use a track instruction to describe one The path of the tool path curve, each track command corresponds to an axis linkage table and a follower table. In the DRC NC program, there are generally m track commands, so there are m axis linkage tables and m Follow the table.

A tool path curve usually consists of several segments of curves, and the geometry of each segment may be different. Invented In the middle, the curve segments with different geometrical structures are regarded as different tool path curves.

After the digital control information distribution process is not real-time, the axis linkage table of the m track commands is stored in the file memory of the servo drive device, and the follow-up table of the m track commands stores the file memory of the digital control information transmitting unit. Therefore, it is necessary to establish a connection with the following table for the separated axis linkage table.

Each track command carries a sequence code that identifies the position of the track command in the DRC NC program. The axis linkage table includes each track command The axis linkage table is used as a subfile, and its directory includes a sequence code; the follower table includes a follower table of each track instruction as a subfile, and the directory also includes a sequence code. Thus, for all trace instructions, the order The code is a correspondence between each track command and its axis linkage table and follower table.

Thus, After the digital control information distribution process is not real-time, in the real-time control process of the tool path curve, the control related coordinate axes are linked, and only the coordinate axis specified by the status word is required to be related to the servo drive device. Send a sync pulse. For the sake of simplicity of the description, the set of synchronization pulses under the control of the status word is referred to as a linkage command.

Therefore, after the digital control information distribution process is not real-time, the digital control information transmission process is simplified to one-way transmission to the servo drive specified by the status word of the track command according to the control rhythm Δ t _i (i = 1, ..., n). Linkage order.

4), digital control information execution process

The digital control information execution process is a process in which the servo drive device follows the linkage command to control the coordinate axis feed to generate a composite displacement.

After receiving the linkage command, the servo drive device reads the coordinate value increment from the axis linkage table according to the L pointer, writes the position loop, and drives the coordinate axis feed to generate a composite displacement; the L pointer is incremented by 1 until the L pointer is equal to the axis linkage table. Last address.

Fifth, the interface

The interface of the numerical control system can be generally divided into an internal interface and an external interface.

1), external interface

The external interface refers to the network interface.

The network interface is used for exchanging information between different digital control systems in the workshop management network, generally adopting an industrial Ethernet interface, etc. , is a conventional technology.

2), linkage interface

The internal interface of the digital control system is used for digital Information is exchanged between four functional components such as a control information generating unit, a digital control information distributing unit, a digital control information transmitting unit, and a digital control information executing unit. The invention divides the internal interface into a real-time interface Interface with non-real time.

The real-time interface includes a linkage interface and an I/O interface. The I/O interface is used to send to the switch in the I/O device Switching instructions are a common technique.

The present invention refers to a real-time interface as a linkage interface for transmitting a linkage command to a servo drive.

In the G code program, the real-time interface is extremely complex, has no reconfigurability, and can only allocate a large amount of computing resources to configure different fieldbuses. This situation led to the Chinese national standard 'GB/T 18759. 2-2006•Mechanical and electrical equipment • Open CNC system • Part 2 Architecture' 5.6 models have been set up to support various fieldbuses (eg CAN, Profibus, Sercos, etc.).

In fact, there are 12 international standards for fieldbus, and manufacturers have more enterprise standards. Unfortunately, multiple standards mean no standards.

In the existing open CNC system based on IEEE definition, the field bus adopts the periodic communication mode to the servo drive in real time. The coordinate value increment generated by the synchronous transmission interpolation, the communication cycle becomes the system parameter, and the real-time synchronization mechanism and the compatibility of the data representation become the key to the transmission.

In the present invention, the digital control information distribution process is separated from the real-time control process of the digital control information, and the axis linkage table Distributed to the servo drive device in real time, the real-time communication process is degenerated to control the rhythm according to the control rhythm, and the servo drive device specified by the status word transmits the linkage command in real time. The real-time control process is highly simplified, and the linkage interface is highly simplified. It is highly simplified.

At the transmitting end, the linkage interface similarly transmits the parallel interface of the status word in a one-way manner according to the rhythm of Δt _i (i = 1,..., n); at the receiving end, one servo drive device is respectively connected with one data bit of the linkage interface , similar to an interrupt control line.

For the servo drive, the linkage command is only a synchronization pulse, and the linkage interface is not a communication interface. Therefore, in the present invention, there is no In the real-time communication process.

3), non-real time interface

The non-real-time interface is used to distribute the axis linkage table to the servo drive in a non-real time in the auxiliary process.

Importantly, the assignment process for the axis linkage table is non-real time. There is no real-time problem and thus there is no need for real-time synchronization mechanism, there is no periodic communication and thus the communication cycle is no longer a system parameter. The axis linkage table is a standard file, and there is no problem of separately developing a communication protocol.

Therefore, the non-real time interface can be any Standard serial interface, including fieldbus, RS232 and RS485 interfaces, USB interface, mobile memory, wireless interface, etc.

Six, programming interface

The so-called programming interface refers to the program interface between the machining programs when exchanging machining programs between different CNC systems.

In the open-ended existing CNC system based on IEEE definition, the G code standard is adopted as the programming interface of the NC machining program.

Unlike the NC machining program of the existing G code, the DRC NC program is characterized by:

1), G code program object-oriented, DRC NC program oriented control flow

G The code program is object oriented. In the G code program, different interpolation commands are used to describe different curves in a tool path curve. For different curves, different interpolation iteration algorithms must be used to implement different interpolation instructions. The real-time processing of the curve is real-time by the interpolation iterative algorithm, which results in the interpolation iterative algorithm becoming an object-oriented closed real-time control algorithm.

In the DRC NC program, the path command is oriented to the machining process of the tool path curve. The DRC NC program is oriented to the control process.

2), standardization of control information

G The code standard is the original product of the initial stage of information technology. Due to the limitation of the paper tape, there is inevitably a defect that the amount of information is too small. Therefore, each manufacturer has extended the basic semantics of the G code, resulting in the dependence of the G code program and the corresponding hardware. The CNC machining program is not interchangeable between different CNC systems, resulting in incompatibility between various CNC systems. It hinders the exchange and sharing of control information, does not have the consistency of human-machine interface, and restricts the openness and reconfigurability of digital control system from the aspect of programming interface.

The axis linkage table and the follower table of the path command carry all the tools needed to process the tool path curve. The digital control information is manufactured non-real-time by the digital control information generating component, allowing each coordinate axis to have different logical attributes.

DRC The NC program, the axis linkage table, the follower table, etc. are transmitted in the system in the form of standardized files, and are also transferred between different CNC systems in the form of files. These files conform to the file specification and use standard file systems such as FAT16 and FAT32. The standardized file becomes the carrier of digital control information, has nothing to do with the hardware platform, has nothing to do with the software platform such as the operating system, has extensive platform independence, and realizes the openness of digital control information. The standardized file replaces the G code program and becomes an easy-to-standardized programming interface that facilitates the standardization of control information.

7. Real-time control of the tool path curve

The execution of the trajectory instruction involves digital control information transmitting components and Servo drive unit. For the sake of simplicity, the digital control information transmitting component is simply referred to as a real-time control module, including a linkage axis setting module, a linkage command setting module, a rhythm control module, and an endpoint control module.

1. The real-time control module sends a linkage command.

T pointer: Used to read Δ t _i (i = 1,..., n) in the follower table.

L pointer: Used to read the coordinate value component in the axis linkage table.

When the trajectory instruction is executed, the trajectory instruction execution module sets the operation flag to start the real-time control module.

Real-time control module The control rhythm dominates the execution of the trajectory command, and the real-time control process of the coordinate axis linkage is transformed into the following process:

Step 1, linkage axis setting Step: According to the sequence code of the track command, the linkage axis setting The module writes the first address of the follower table to the T pointer, reads the status word from the follower table and writes it to the status word register, specifying the coordinate axis of the linkage;

Step 2: linkage command setting step: according to the T pointer, the linkage command setting module reads Δ t _i (i = 1,..., n) in the follow-up table and writes to the T-split timer;

Step 3. Rhythm control step: the timing time in the T split timer is up, the rhythm control module starts The pulse generator outputs a pulse, and sends a linkage command to the servo drive device specified by the status word register through the linkage interface;

Step 4: End point control step: the end point control module controls the end point of the track command. If the T pointer is equal to the last address of the follower table, that is, the end point of the track command is reached, the running flag is turned off; otherwise, the T pointer points to the next Δ t _i , repeating Step 2 to step 4;

Trajectory instruction execution module query real-time control module The run flag, if the end of the track command is reached, the next motion command is executed.

2, servo drive control axis feed

After the servo drive device receives the axis linkage table, the execution flag is set to '1'; according to the sequence code of the axis linkage table of the track command, the first address of the axis linkage table is written into the L pointer; according to the feature table in the axis linkage table file, Set the logical properties of the axes.

After receiving the linkage command, the servo drive device follows the linkage command, and the axis linkage table control module reads the coordinate value increment from the axis linkage table according to the L pointer, writes the position loop, and drives the coordinate axis feed to generate a synthetic displacement; the L pointer adds 1 Until the L pointer is equal to the end address of the axis linkage table, set the execution flag to '0' to prepare the axis linkage table for the next track command.

In this way, the real-time control process of the so-called tool path is to control the specified by the status word according to the control rhythm. The process by which the servo drive reads the coordinate value increment from the axis linkage table and writes it to its position loop. Real-time control module A linkage command is generated; following the linkage command, the servo drive continuously drives the coordinate axis feed to generate a composite displacement. This is repeated until the T pointer reaches the end address of the slave table, that is, the end of the track command is reached.

For example, for 5-axis linkage of X, y, Z, A, B, etc., the status word is '11111000', and its real-time control process is that the real-time control module continuously controls the control rhythm Δ t _i (i = 1) in the follow-up table. ,..., n) Write the T-split timer, generate a linkage command and send a linkage command to the servo drive devices such as X, y, Z, A, B through the linkage interface; servo drives such as X, y, Z, A, B, etc. Then, following the linkage command, the respective axis linkage table control modules continuously read Δ X _i , Δ y _i , Δ Z _i , Δ A _i , Δ B _i from the respective axis linkage tables and write them into the position loop. The drive axis feed produces a resultant displacement. This is repeated until the end of the path curve.

Eight, the system implementation of the technical solution

In the existing open CNC system based on IEEE definition, the interpolation cycle of the real-time operating system and the communication cycle of the field bus are two system clocks. Following the cycle of the interpolation cycle and the communication cycle, the number of the toolpath curve Control information is continuously generated, distributed, transmitted, and executed, so that the real-time iteration of the digital control information and the real-time iteration of the control process are repeated. In this architecture, the real-time control of the toolpath curve includes both The real-time iteration of the digital control information and the real-time iteration of the control process, including the real-time communication process, involving the accuracy and speed of the interpolation iterative algorithm, the geometric features of the tool path curve, the process characteristics of the machining process, A series of complex factors such as kinematics/kinetics of mechanical systems, hardware platforms such as processor bits and computing speed, and software platforms such as real-time operating systems.

The technical solution configures control resources according to a control flow of generating, distributing, transmitting, and executing digital control information, wherein the generating process and the assigning process are non-real-time processes, and the sending process and the executing process are real-time processes.

The technical solution simplifies the real-time control process of the tool path curve into a one-way transmission linkage command to the servo drive device designated by the state word through the linkage interface according to the control rhythm Δ t _i (i = 1,..., n) in the follow-up table. The servo drive device follows the linkage command, and sequentially writes the coordinate value increments in the axis linkage table to the position loop, and drives the corresponding coordinate axes to generate a combined displacement. Thus, the digital control information execution process is decoupled into a linked information execution process and a location information execution process.

The technical solution replaces the interpolation period with the control rhythm Δ t _i (i = 1,..., n) in the follow-up table, and cancels the control right of the real-time operating system to the real-time control process. The technical solution replaces the extremely complicated real-time communication with the simplest one-way transmission of the linkage command, and cancels the control right of the current bus to the real-time control process. Therefore, the above technical solution completely eliminates the constraints of the operating system and the current bus on the real-time control process, and points out the direction for the system implementation technology of the reconfigurable digital control system.

Figure 1 shows A process model diagram based on a control flow, where the solid line represents the real-time process and the dashed line represents the non-real-time process. For the sake of clarity, the execution of the feedback information in the servo drive can be added to Figure 1, as shown in Figure 2.

Compared with the processing data model of the existing open CNC system based on IEEE definition, the above process model clearly describes the architecture of the open CNC system and reveals the technical solutions for rationally configuring control resources in different control processes. Key technology.

In order to more clearly illustrate the technical solution and compare it with the system implementation technology of the existing open CNC system defined by IEEE, a visual example is given.

A band plays a symphony, a symphony is equivalent to a knife curve, a variety of instruments are equivalent to the axis, the actor is equivalent to a servo drive, real-time The operating system is equivalent to the band conductor.

In the existing open CNC system based on IEEE definition, in the performance of the symphony (The machining process of the tool path curve), the actors (servo drive units) do not know in advance what tune of the tune music (knife curve), the band conductor (real-time operating system) must be harmonized at the performance site. The music is divided into several segments according to the equal-length time slice (interpolation cycle) (real-time interpolation calculates the coordinate value increment), and each piece is told each time in a real-time manner. The actor (real-time communication with the servo drive via the current bus), each actor records each piece of music in real time for performance. The extreme complexity of this model is obvious.

In this technical solution, through rehearsal (discrete geometric programming and discrete motion planning), the symphony is divided into several segments according to its inner melody (the unequal rhythm Δ t _i in the follower table), and for each actor A score (the distribution axis linkage table) marked in the order of the segments is assigned in advance, and the band command (real-time control module) only needs to follow the control rhythm Δ t _i (i = 1,..., n ) in the follow-up table. Each actor is told by a baton (a linkage command via a linkage interface), and each actor follows the command from the baton to flip through his score (axis linkage table) for performance. The high degree of simplicity of this model is also obvious.

1, a number of definitions

1), digital control information generating part

Digital control information generation component based on PC, including State command generation module, switch command generation module, track command generation module, DRC NC program generation module.

2), CNC application system

The numerical control application system includes a DRC numerical control program file memory, an interpreter memory, and a DRC numerical control program running module.

DRC The NC program running module includes a motion instruction fetching module, a state instruction execution module, a switch instruction execution module, and a track instruction execution module.

The motion instruction fetch module is used to write the first address of the DRC NC program to the motion instruction pointer and read the motion instruction. The function byte of the motion instruction is written into the motion instruction register, and the address of the next motion instruction is written into the motion instruction pointer; the motion instruction pointer is used to specify the address of the next motion instruction;

If the motion instruction is a status instruction, the status instruction execution module executes an interpretation program of the status instruction; if the motion instruction is a switch instruction, the switch instruction execution module executes an interpretation program of the switch instruction; if the motion instruction is a track instruction, the track instruction execution module executes The interpreter for this trace instruction.

3), digital control information distribution unit

The digital control information distribution process is to assign the coordinate value increments in the linkage table to the relevant servo drive device, for example, assign Δ X _i , Δ y _i , Δ Z _i , Δ A _i , Δ B _i to X, y, Servo drive devices with five axes, Z, A, B, etc.

The digital control information distribution unit includes an axis linkage table file memory, an axis linkage table allocation module, and a serial interface.

4), digital control information transmission unit

Digital control information transmitting unit for using the control law to the status word The specified servo drive sends the linkage command in real time. For the sake of simplicity, the digital control information transmitting unit is referred to as a real-time control module.

The real-time control module involves reading the control rhythm Δ t _i (i = 1,..., n) and the status word from the file memory from the file memory. The follower table is a standard file that is written to the file memory by the operating system of the PC, such as the FAT16, FAT32 file system specification. In the present invention, the file memory is configured with a solidified follower file analysis module for reading the associated sector address and data area address of the FAT table, FDT table, BPB table, etc., so as not to be related to the operating system.

5), digital control information execution unit

The digital control information execution unit includes a servo drive device and an I/O device. As a conventional technique, the present invention does not relate to a control flow for controlling an I/O device.

The digital control information execution process is that the servo drive device writes the coordinate value increment to the position loop and drives the coordinate axis feed.

6), motion control interface

The motion control interface includes a non-real-time interface and a linkage interface;

The non-real time interface is a variety of standard serial interfaces, such as Fieldbus, RS232 interface, RS485 interface, USB interface, mobile memory, wireless interface, etc.

The linkage interface, at the transmitting end, continuously unidirectionally transmits a parallel interface of the status word in a unidirectional manner according to the rhythm of Δt _i (i = 1, ..., n), including a status word register, a T pointer, a T-split timer, and a pulse Generator; at the receiving end, a servo drive is connected to a data bit of the linkage interface, similar to an interrupt control line.

2, the architecture

Figure 3 is A schematic diagram of an architecture of a reconfigurable numerical control system, and FIG. 4 to FIG. 6 are functional block diagrams of various components. Including PC system 1, data stream controller 2, servo drive unit 3, I/O device 4, serial interface 6 , distribution interface 7, linkage interface 8, I / O interface 9; PC system 1 through the serial interface 6 and data flow controller 2; data flow controller 2 through the distribution interface 7, linkage interface 8 It is connected to the servo drive unit 3, and is connected to the I/O device 4 via the I/O interface 9.

The invention provides a digital control information distribution component and a real-time control module The CNC application system is integrated into a separate component called a data flow controller.

The PC system 1 is a digital control information generating unit that is connected to the data stream controller 2 via the serial interface 6. Data stream controller 2 As an embedded system, including microprocessor 21, digital control information distribution unit (file memory 23 , axis linkage table allocation module 24), numerical control application system (interpreter program memory 22, DRC numerical control program operation module 25), digital control information transmitting component (real-time control module 26) and interrupt management module 27, through the distribution interface 7 and linkage The interface 8 is connected to the servo drive unit 3, and is mounted on the I/O interface 9 and I/O. Set 4 connections to form a split architecture.

PC system 1 The DRC NC program, the axis linkage table, the follower table, etc. of the workpiece can be transmitted to the serial interface 8 through a network interface, a field bus, an RS232 and RS485 interface, a mobile memory or a wireless interface. Data stream controller 2.

Generate a DRC NC program in the PC system, It becomes an open platform for NC programming; the PC system generates the axis linkage table and the follower table of the tool path curve, and becomes an open development platform for numerical control technology. The PC system can also transfer DRC NC programs and axes for machining workpieces via the Internet. Linked tables, follow-up tables, and other documents.

The data stream controller 2 acts as an embedded system and is only used to run the DRC NC program and send linkage commands without configuring any embedded The operating system, function and structure are extremely simple and highly reliable.

Data Flow Controller 2 can be independently configured in a CNC device and with a PC system Completely independent. A PC can serve multiple CNC equipment, especially for integrated control. Reconfigurable production line consisting of multiple CNC machine tools, digital fixtures, handling robots, etc.

PC The system 1 is used to generate a DRC numerical control program for controlling the workpiece machining process, including a state instruction generation module 11, a switch instruction generation module 12, a track instruction generation module 13, a DRC numerical control program generation module 14, and a state instruction generation module 11 for generating control assistance. State instruction of the process; switch instruction generation module 12 is used to generate control a switch instruction of the I/O device; the state instruction generation module 11 is further configured to generate a reconstruction instruction, where the reconstruction instruction is used to modify the state instruction and the interpretation program of the switch instruction; The trajectory command generating module 13 is configured to generate a trajectory command for controlling the servo drive device to complete the path curve pass process; the DRC NC program generating module 14 is configured to link the state command, the switch command, and the trajectory command to the DRC numerical control program according to the machining process.

The trajectory instruction generation module 13 includes a discrete geometry planning module 131 and a discrete motion planning module 132. The discrete geometric planning module 131 is configured to generate an L-segment linkage table storing a tool path curve; the L segmentation is used to control the coordinate axis linkage to generate a composite displacement; the linkage table is divided into an axis linkage table of each axis, and the axis is divided into The linkage table is used to store the L-segment component of the relevant coordinate axis, and the axis is controlled to generate the axis displacement. The discrete motion planning module 132 is configured to store a T-segment of the tool path curve and a follow-up table of the status word; the T-segment is used to control a time interval between the axis displacements; the status word is used to specify the coordinate of the linkage axis.

The data stream controller 2 includes a microprocessor 21, an interpreter memory 22, a file memory 23, an axis linkage table allocation module 24, and a DRC. The NC program runs module 25, real-time control module 26 and interrupt management module 27.

The interpreter memory 22 is used to store an interpreter of the above-described status command, switch command, and track command.

The file memory 23 is used to receive and store the DRC NC program, the follower table, and the axis linkage table through the serial interface 6.

The axis linkage table assignment module 24 is for distributing the axis linkage table to the servo drive unit 3 via the distribution interface 7.

DRC NC program operation Module 25 is used to run the DRC NC program, execute the status command, control the auxiliary process The execution switch command controls the I/O device 4 through the I/O interface 9 and executes the trajectory command to control the servo drive device 3 to complete the machining process of the tool path curve through the linkage interface 8. The motion instruction fetch module 251, the state command execution module 252, the switch instruction execution module 253, and the track instruction execution module 254 are used; the motion instruction fetch module 251 is configured to write the address of the motion instruction in the DRC NC program to the motion instruction pointer and read Take the motion instruction, Writing a function byte of the motion instruction to the motion instruction register; if the motion instruction is a state instruction, according to the address table of the motion instruction, the state instruction execution module 252 jumps to the entry address specified by the address table, Executing an interpreter of the status instruction; if the motion instruction is a switch instruction, the switch instruction execution module 253 jumps to an entry address specified by the address table according to an address table of the switch instruction, The interpreter of the switch instruction is executed; if the motion instruction is a track instruction, the track instruction execution module 254 is configured to execute an interpreter of the track instruction.

The real-time control module 26 is configured to transmit a linkage command to the servo drive device 3 via the linkage interface 8 in accordance with the control rhythm Δ t _i (i = 1, . . . , n) in the follow-up table. The linkage coordinate axis setting module 261, the linkage command setting module 262, the rhythm control module 263, and the endpoint control module 264 are included. The linkage coordinate axis setting module 261 is configured to write the address of the follow-up table to the T pointer, read the status word from the 1 follow-up table and write the status word register, and specify the coordinate axis of the linkage; 1 linkage command setting module 262 is used for Reading Δ t _i (i = 1,..., n) in the follow-up table and writing to the T-split timer; the timing time in the T-segment timer is up, the rhythm control module 263 starts the pulse generator to output a pulse And transmitting a linkage command to the servo drive device specified by the status word register through the linkage interface 8; the end point control module 264 is configured to control the end point of the track instruction, and if the T pointer is equal to the last address of the follow-up table, the operation flag is turned off Otherwise, the T pointer points to the next control rhythm Δ t _i .

The interrupt management module 27 is for processing real-time feedback information from the servo drive unit 3.

The servo drive unit 3 is provided with an axis linkage table initialization module 31 and an axis linkage table control module 32. Axis linkage table initialization The module is configured to set an execution flag, and write the first address of the axis linkage table to the L pointer according to the sequence code of the track instruction; following the linkage command, the axis linkage table control module reads the axis from the axis linkage table according to the L pointer. The coordinate value increment is written to the position loop, and the drive coordinate axis feed generates a composite displacement until the L pointer is equal to the last address of the axis linkage table, and the execution flag is turned off.

The axis linkage table file further includes a feature table; the feature table is used to identify a logical attribute of the coordinate axis; the logic attribute includes a feed equivalent, a number of bytes of data, and an electronic gear ratio. In the existing open CNC system based on IEEE definition, the interpolation iterative algorithm requires that the linked axes must have the same logic. Attributes . Once the logical attributes of the coordinate axes are different, for example, the feed equivalents (nano, micro, etc.) are different, the number of bytes of data is different, etc., the functions and structures of the numerical control system must be changed accordingly, from real-time control process and real-time communication. The two aspects of the process restrict the openness and reconfigurability of the system. Thus, this technical feature overcomes the above drawbacks.

The distribution interface 7 is also a serial interface and is only used for transmission to the servo drive 3 in a non-real time process. The axis linkage table, therefore, its specific structure is not limited by any means, field bus, RS232 interface, RS485 interface, USB interface or wireless interface can be used. This means that there is no need to assign interface 7 The standard is set, in other words, the distribution interface 7 has been standardized.

In summary, in the technical solution, the system implementation technical solution of the reconfigurable numerical control system has the following technical features:

The control flow is divided into four sub-processes: digital control information generation process, digital control information distribution process, digital control information transmission process and digital control information execution process, and corresponding control resources are configured;

The digital control information generation process and the digital control information distribution process are not real-time;

The DRC numerical control program written by the state command, the switch command, and the track command is used as a programming interface;

The track command has only one format, regardless of the type of curve in the tool path curve.

Track command and linkage table Separating the follower table; the axis linkage table of each coordinate axis in the linkage table is used as an independent subfile, and is allocated to the servo drive device through the non-real time serial interface in the auxiliary process and stored in its axis linkage table memory; Moving table Set the status word to specify the coordinate axis of the linkage. The number of bytes of the status word is the user parameter. The axis linkage table file sets the characteristic table, which is used to set the logic attribute of the coordinate axis, so that the coordinate axis logic The processing of the attribute is moved forward to the servo drive;

The file conforms to the file specification and uses standard file systems such as FAT16, FAT32. Standardized files become the carrier of digital control information, independent of the hardware platform, and independent of software platforms such as operating systems.

The technical solution divides the digital control information distribution component and the real-time control module The CNC application system is integrated into a separate component called a data flow controller.

In terms of architecture, the PC system is a digital control information generating component that is connected to the data flow controller through a serial interface. Data flow controller as an embedded system, including The digital control information distribution unit, the numerical control application system, and the digital control information transmitting unit are connected to the I/O device through the distribution interface and the linkage interface and the servo drive device to form a split type. The architecture.

The PC system transfers control of the real-time control process of the toolpath curve to the data flow controller. The real-time control module in the data flow controller sends a linkage command to the servo drive specified by the status word through the linkage interface according to the control rhythm Δ t _i (i = 1,..., n) in the follow-up table; the servo drive device follows The linkage command sequentially writes the coordinate value increments in the axis linkage table to the position loop successively, and drives the corresponding coordinate axes to generate a combined displacement.

The above technical features greatly simplify the real-time control method of the tool path curve, resulting in the architecture of the reconfigurable computer digital control system and A major change in real-time control methods and the refactoring of reconfigurable computer digital control systems with extremely simple technical means.

The digital control method based on the above reconfigurable numerical control system includes the following steps:

Step 1. DRC NC program generation steps: For PC system 1 to generate DRC NC program, including the following Steps:

Step 101: Track instruction generation Step: The trajectory command generation module generates a trajectory command for controlling the servo drive device to complete the path curve pass process, including discrete geometric planning steps and discrete motion planning steps; discrete geometric planning steps The discrete geometric planning module generates an L-segment linkage table storing a tool path curve; the L segmentation is used to control the coordinate axis linkage to generate a synthetic displacement; the linkage table is divided into an axis linkage table of each axis, and is used for storing each The L-segment component of the coordinate axis controls the axis to generate the axis displacement; discrete motion planning The step is for the discrete motion planning module to generate a follow-up table of the T-segment and the status word storing the tool path curve; the T-segment is used to control the time interval between the axis displacements; the status word is used to specify the linkage Axis.

Step 102: State Instruction Generation Step: The state instruction generation module generates a state instruction that controls the auxiliary process.

Step 103: Switch instruction generation Step: The switch instruction generation module generates a switch instruction for controlling the I/O device.

Step 104, DRC NC program generation Step: DRC The numerical control program generating module links the state command, the switch command, and the track command to a DRC numerical control program according to a machining process.

Step 2, Axis linkage table assignment Step: Axis linkage table assignment in data flow controller 2 The module assigns the axis linkage table to the servo drive unit 3 via the distribution interface 7.

Step 3. DRC NC program operation Step: DRC NC program running in data flow controller 2 Module operation The DRC NC program includes the following steps:

Motion instruction fetching step: the motion instruction fetching module writes the first address of the DRC NC program to the motion instruction pointer and reads the motion instruction, The function byte of the motion instruction is written into the motion instruction register, and the address of the next motion instruction is written into the motion instruction pointer; the motion instruction pointer is used to specify the address of the next motion instruction;

State instruction execution step: if the motion instruction in the motion instruction fetching step is a state instruction, the state instruction execution module jumps to the entry address specified by the address table according to the address table of the state instruction, and executes the state instruction Interpreter

The switch instruction execution step: if the motion instruction in the motion instruction fetching step is a switch instruction, the switch instruction execution module jumps to an entry address specified by the address table according to an address table specified by the address code of the switch instruction, Execute the interpreter of the switch instruction;

The trajectory instruction execution step: if the motion instruction in the motion instruction fetching step is a trajectory instruction, the trajectory instruction execution module executes an interpreter of the trajectory instruction.

The PC system 1 transmits the DRC NC program, the axis linkage table, the follower table, etc. of the workpiece to the workpiece through the serial interface. Data stream controller 2. The data flow controller first assigns an axis linkage table to the servo drive unit 3 and then runs the DRC NC program. When the trajectory command is run, the trajectory instruction execution module The running flag is set, and the real-time control module 26 is activated to transfer the control of the real-time control process of the tool path to the real-time control module.

The real-time control module 26 sends a linkage command to the servo drive device 3 through the linkage interface 8 according to the control rhythm Δ t _i (i = 1,..., n) in the follow-up table; each servo drive device 3 follows the linkage command, and each of them The coordinate value increments in the axis linkage table are successively written into the position loop, driving the respective coordinate axes to feed, and the resultant displacement is generated. So repeatedly, until the T pointer is equal to the last address of the slave table, that is, the end of the track command is reached, the running flag is turned off, and the DRC NC program running module executes the next motion command.

After the trajectory instruction execution module 254 hands over the control to the real-time control module 26, it is in the query state, and the real-time control module 26 is queried. Operating status . If the run flag is off, the next motion command is executed until the stop command is executed, ending the machining of the workpiece.

Specifically, the real-time control process of the tool path includes the following steps:

Step a, linkage coordinate axis setting Step: According to the sequence code of the track instruction, the linkage axis setting The module 261 writes the first address of the follower table to the T pointer, reads the status word from the follower table and writes the status word register, and specifies the coordinate axis of the linkage;

Step b, linkage command setting step: according to the T pointer, the linkage command setting module 262 reads Δ t _i (i = 1, ..., n) in the follow-up table and writes to the T-split timer;

Step c, rhythm control step: the timing time in the T split timer is up, the rhythm control module 263 starts The pulse generator outputs a pulse, and sends a linkage command to the servo drive device 3 specified by the status word register through the linkage interface 8;

Step d, linkage table control step: following the linkage command, the axis linkage table control module 31 of the servo drive device 3 reads the coordinate value increment from the axis linkage table according to the L pointer, writes the position loop, and drives the coordinate axis into Give a synthetic displacement;

Step e: End point control step: the end point control module 264 controls the end point of the trajectory command. If the T pointer is equal to the last address of the follower table, that is, the end point of the trajectory command is reached, the running flag is turned off; otherwise, the T pointer points to the next Δt _i , repeat steps b through e.

For the reconstruction of mechanical systems, motion planning must first be performed on the mechanical system.

CAD/CAM/CAE The wide application of technology, especially the CAE technology computer-aided solution to the multi-dimensional motion relationship, stiffness, stability, dynamic response, thermal deformation and other problems of complex mechanical systems, and the optimization of structural performance, has become the movement of mechanical systems. A numerical calculation tool essential for planning and structural optimization. Thus, in In this embodiment, the motion planning of the mechanical system is considered a conventional CAE technique.

The reconstruction of the reconfigurable numerical control system of the present embodiment involves the following problems.

1), reconstruction problem of discrete coordinate system

After the mechanical system is reconstructed, CAE performs motion planning and structural optimization on the mechanical system to obtain the motion relationship of the mechanical system. For the reconstructed mechanical system, the discrete coordinate system must be reconstructed.

2), the reconstruction problem of the structure constant database

After the mechanical system is reconfigured, the mechanical properties change. Reconstruction based on mechanical properties reconstructed from the mechanical system The structure constant database; the mechanical attributes include the linear structure error of the coordinate axis, the angular displacement error, the backlash and other fine structure constants, and the coordinate system parameters such as non-parallelism and non-perpendicularity between the coordinate axes.

3), state command and switch instruction reconstruction problem

The reconstruction instructions are used for reconstruction of state instructions and switch instructions.

In this embodiment, the state command and the switch command have the same format. In this embodiment In the explanation program of the status instruction and the switch instruction, an address table for storing the entry address of the interpreter of the status instruction and the switch instruction is specifically set. The address table is open to the user.

The status command involves an auxiliary function operation, and the switch instruction relates to the switch quantity control in the I/O device, both of which are related to the mechanical system. The specific structure is inseparable and belongs to the personalization function. After the mechanical system is reconfigured, state commands and switching instructions often need to be reconstructed. The user can define the parameter values in their auxiliary bytes and define their functions by rewriting the interpreter.

To this end, in this embodiment In the middle, the status command to rewrite the interpreter is set. This state instruction that rewrites the interpreter is called a refactoring instruction.

For the refactoring instruction, the address of the interpreter includes the source address and the destination address, and the address space is also different, or 16 bits, 32 bits, 64 bits, and the like. For different address spaces, the reconstruction instructions carry different parameters of different nature. For example, for a 32-bit address space, the reconstruction instruction carries five parameters of three different properties: 2 source address parameters, 2 target address parameters, 1 byte number parameter.

The user reads the entry address of the interpreter from the address table as a target address parameter, and uses the start address of the interpreter itself as the source address parameter, and the capacity of the interpreter itself written as the byte number parameter. The reconstruction instruction is used to reconstruct the state instruction and the switch instruction.

Writing an interpreter for state and switch instructions is a simple, conventional technique.

4), real-time control process reconstruction problem

The reconstruction of the real-time control process involves the reconstruction of the trajectory instructions and the reconstruction of the linkage interface.

Existing open CNC systems based on IEEE definitions are object oriented rather than process oriented. In the interpolation iterative control method, the real-time control process is both an iterative process of digital control information and an iterative process of real-time control process. Thus, the real-time control process and the geometric characteristics of the tool path curve, the process characteristics of the machining process, the mechanical system Kinematics / The dynamic characteristics are inseparable, and are inseparable from the hardware platforms such as the number of bits of the CPU and the operation speed. They are inseparable from the software platforms such as the real-time operating system, and are inseparable from the interpolation iterative algorithm. The real-time control process of the tool path curve cannot be opened and is not reconfigurable. For different curve types, special interpolation instructions must be defined and configured The interpolation module is fixed, so the interpolation instructions under the G code standard are not reconfigurable.

The trajectory command in the present invention is only related to the number of linked coordinate axes, regardless of the type of curve in the tool path curve. There is no refactoring problem.

The prior art regards 5-axis linkage as the most advanced technology. In the technical solution, the coordinate axes of the linkage are in the following table. The status word specifies that the number of bits and the number of bytes of the status word are user parameters. An 8-bit status word can control 8 coordinate axes, and a 16-bit status word can control 16 coordinate axes. Thus, for the vast majority of users, there is no refactoring problem. If the number of axes of the mechanical system exceeds the number of bits of one status word, in the present invention, it is only necessary to set the user parameter of the status word to two or more bytes, and to configure two or more linkage interfaces. Therefore, there is no need Refactoring. The format of the trajectory command proposed by the technical solution is applicable to any mechanical system and has wide versatility.

In the technical solution, the real-time control process of the tool path curve is simplified to the one-way transmission linkage of the servo drive device specified by the state word through the linkage interface Δ t _i (i = 1,..., n) in the follow-up table. The command simplifies the real-time control of the toolpath curve to start the real-time control module. The operation of the real-time control module is independent of the operating system by a built-in solidified follower file analysis module.

The follower table is a data file using a standard file system such as FAT16, FAT32, etc., the follower table The file memory has a built-in firmware follow-up table file analysis module for reading digital information in the follow-up table. Therefore, the real-time control process of the tool path curve has nothing to do with the software platform such as the operating system.

The linkage interface of the technical solution is not a communication interface, and the linkage command is only a synchronization pulse. At the transmitting end, the linkage interface similarly transmits the parallel interface of the status word in a one-way manner according to the rhythm specified by Δt _i (i = 1,..., n); at the receiving end, one servo driver and one data bit of the linkage interface respectively Connection, the linkage interface is similar to an interrupt control line. Therefore, the linkage interface proposed by the technical solution does not have a reconstruction problem.

5), non-real-time interface reconstruction problem

The non-real-time interface is a standard serial interface such as a standard USB interface or other standard serial interface supported by the UART. , is a conventional technology. For the reconstruction of the mechanical system, the non-real time interface does not need to be reconstructed.

Specifically, the method for reconstructing the reconfigurable numerical control system of the technical solution includes the following steps:

Step 1. Reconstruct the discrete coordinate system: the digital control information generating component reconstructs the discrete coordinate system; the discrete coordinate system includes an orthogonal discrete coordinate system and a non-orthogonal discrete coordinate system.

Step 2: reconstructing a structure constant database: the digital control information generating component reconstructs a structure constant database; the structure constant database stores a fine structure constant of the coordinate axis and a coordinate system parameter; the fine structure constant of the coordinate axis includes a line displacement error, Angular displacement error, backlash; the coordinate system parameters include non-parallelism and non-perpendicularity between the coordinate axes.

Step 3. Construction state Reconstruction of the instruction: The digital control information generation component constructs the state instruction reconstruction instruction The method includes the following steps: Step 31: setting a target address parameter of the reconfiguration instruction: setting an entry address in an address table of the status instruction as a target address parameter of the reconfiguration instruction; Step 32: Setting a source address parameter of the refactoring instruction: setting a starting address of the rewritten interpreter as a source address parameter of the refactoring instruction; and step 33, setting a byte number parameter of the refactoring instruction: an explanation to be rewritten The capacity of the program is set to the number of bytes parameter. Step 34: Construct a reconstruction instruction: construct a reconstruction instruction of the state instruction according to the target address parameter, the source address parameter, and the number of bytes parameter.

Step 4: Constructing a switch Restructuring of an instruction: A digital control information generating component constructs a reconstruction instruction of the switch instruction , comprising the following steps: Step 41: setting a target address parameter of the reconstruction instruction: the switch The entry address in the address table of the instruction is set as the target address parameter of the reconstructed instruction; Step 42: setting the source address parameter of the reconstructed instruction: setting the start address of the rewritten interpreter as the source address parameter of the reconstructed instruction; Step 43, setting a byte number parameter of the refactoring instruction: setting a capacity of the rewritten interpreter to a byte number parameter; and step 44, constructing a reconfiguration instruction: according to the target address parameter, the source address parameter, The byte number parameter is configured to construct a reconstruction instruction of the switch instruction.

Step 5: Running a reconfiguration instruction: the digital control information sending component runs the state instruction Reconfiguring the instruction, reconstructing the state instruction, executing a reconstruction instruction of the switch instruction, and reconstructing the switch instruction.

The above is a further detailed description of the reconfigurable numerical control system in conjunction with the specific preferred embodiments, and the specific implementation of the present invention is not limited to these descriptions. It will be apparent to those skilled in the art that the present invention may be made without departing from the spirit and scope of the invention.

Claims

A reconfigurable numerical control system, comprising: a PC system, a data flow controller, a servo drive device, an I/O device, Serial interface, distribution interface, linkage interface, I/O interface

The PC system is connected to the data flow controller through a serial interface;

The data flow controller is connected to the servo driving device through a distribution interface and a linkage interface, and the data flow controller Connecting to the I/O device through an I/O interface;

The PC system is configured to generate a DRC numerical control program for controlling a workpiece machining process, including a state instruction generation module, a switch instruction generation module, a track instruction generation module, and a DRC numerical control program generation module;

The state instruction generating module is configured to generate a state instruction that controls the auxiliary process;

The switch instruction generation module is configured to generate a switch instruction for controlling an I/O device;

The state instruction generation module is further configured to generate a reconstruction instruction, where the reconstruction instruction is used to modify the state instruction and the interpretation program of the switch instruction.

The trajectory command generating module is configured to generate a trajectory command for controlling a servo drive device to complete a path curve pass process;

The DRC numerical control program generating module is configured to link a state instruction, a switch instruction, and a track instruction to a DRC numerical control program according to a machining process;

The track instruction generation module includes a discrete geometric planning module and a discrete motion planning module;

The discrete geometric planning module is configured to generate an L-segment linkage table storing a tool path curve; the L segmentation is used to control coordinate axis linkage to generate a composite displacement; the linkage table is divided into an axis linkage table of each axis, The axis linkage table is used for storing the L segmentation component of the relevant coordinate axis, and controlling the coordinate axis to generate the axis displacement;

The discrete motion planning module is configured to store a T-segment of the tool path curve and a follow-up table of the status word; the T-segment is used to control a time interval between the axis displacements; the status word is used to specify linkage Axis;

The data flow controller includes a microprocessor, an interpreter memory, a file memory, an axis linkage table allocation module, and a DRC NC program running Module, real-time control module and interrupt management module;

The interpreter memory is configured to store the state instruction, the switch instruction, an interpreter of the trace instruction;

The file storage is configured to receive and store the DRC numerical control program, the follow-up table, and the The shaft linkage table;

The axis linkage table distribution module is configured to allocate the axis linkage table to the servo drive device through the distribution interface;

The DRC NC program running module is configured to run the DRC numerical control program, execute the status instruction, control an auxiliary process, and execute the And a switch command controls the I/O device through the I/O interface, and executes the track command to control the machining process of the tool path by the servo drive device through the linkage interface;

The real-time control module is configured to send a linkage command to the servo driving device through the linkage interface according to a control rhythm Δ t i (i=1, . . . , n) in the follow-up table; Controlling synchronization between coordinate axes specified by the status word;

The interrupt management module is configured to process real-time feedback information from the servo drive device;

The servo drive device is provided with an axis linkage table initialization module and an axis linkage table control module;

The axis linkage table initialization The module is configured to set an execution flag, and write an address of the axis linkage table to the L pointer according to the sequence code of the track instruction;

Following the linkage command, the axis linkage table control module reads the coordinate value increment of the axis from the axis linkage table according to the L pointer and writes the position loop, and drives the coordinate axis feed to generate a composite displacement.
The reconfigurable numerical control system of claim 1 further characterized in that the number of bytes of said status word is a user parameter.
The reconfigurable numerical control system of claim 1 further characterized in that said axis linkage table file further comprises a feature table; said feature table is for identifying a logical attribute of the coordinate axis; and said logical attribute comprises a feed Equivalent, number of bytes of data, electronic gear ratio.
A reconfigurable numerical control system according to claim 1 further characterized by Each data bit of the linkage interface is connected to a servo drive.
The reconfigurable numerical control system of claim 1 further characterized by: said serial interface and said The distribution interfaces are fieldbus, RS232 interface, RS485 interface, USB interface or wireless interface.
A reconfigurable computer numerical control system according to claim 1 further characterized in that said file memory in said data stream controller comprises a follower table file. The analysis module; the follower table file sector analysis module is configured to read the DRC numerical control program, the follow-up table, and the axis linkage table.
The reconfigurable numerical control system according to any one of claims 1 to 6, further characterized in that said data flow controller The DRC program running module includes a motion instruction fetching module, a state instruction execution module, a switch instruction execution module, and a track instruction execution module;

The motion instruction fetching module is configured to write the address of the motion instruction in the DRC NC program into the motion instruction pointer and read the motion instruction, and The function byte of the motion instruction is written to the motion instruction register;

If the motion instruction is a status instruction, the status instruction execution module jumps to an entry address specified by the address table according to an address table of the status instruction, Execute an interpreter of the status instruction;

If the motion instruction is a switch instruction, the switch instruction execution module jumps to an entry address specified by the address table according to an address table of the switch instruction, Execute the interpreter of the switch instruction;

If the motion instruction is a trajectory instruction, the trajectory instruction execution module is configured to execute an interpreter of the trajectory instruction.
A reconfigurable numerical control system according to claim 7, wherein said trajectory instruction execution module sets a running flag for activating said real-time control module ;

The real-time control module includes a linkage coordinate axis setting module, a linkage command setting module, a rhythm control module, and an end point control module;

The linkage axis setting The module is configured to write the address of the follow-up table to the T pointer, read the status word from the follow-up table and write the status word register, and specify the coordinate axis of the linkage;

The linkage command setting module is configured to read Δt i (i=1, . . . , n) in the following table and write a T-split timer;

The timing time in the T split timer is up, the rhythm control module starts the pulse generator to output a pulse, and assigns to the status word register through the linkage interface. The servo drive device sends a linkage command;

The endpoint control module is configured to control an end point of the trajectory instruction, and if the T pointer is equal to the last address of the follower table, the running flag is turned off; otherwise, the T pointer points to the next time increment Δt i .
A reconstruction method of a reconfigurable numerical control system, comprising the steps of:

Step (1), reconstructing a discrete coordinate system: the digital control information generating component reconstructs a discrete coordinate system; the discrete coordinate system includes an orthogonal discrete coordinate system and a non-orthogonal discrete coordinate system;

Step (2): reconstructing a structure constant database: the digital control information generating component reconstructs a structure constant database; the structure constant database stores a fine structure constant of the coordinate axis and a coordinate system parameter; the fine structure constant of the coordinate axis includes a line displacement Error, angular displacement error, backlash; the coordinate system parameters include non-parallelism and non-perpendicularity between the coordinate axes;

Step (3), construction state Reconstruction of instruction Instruction: Digital control information generation component constructs the state instruction reconstruction instruction ;

Step (4), construction switch instruction reconstruction instruction: digital control information generation component constructs reconstruction instruction of the switch instruction ;

Step (5), running a reconfiguration instruction: the digital control information transmitting component runs a reconfiguration instruction of the state instruction, reconstructs the state instruction, and performs reconfiguration of the switch instruction An instruction to reconstruct the switch instruction.
The method of reconstructing a reconfigurable numerical control system according to claim 9, wherein said step (3) comprises the steps of:

Step (31), setting a target address parameter of the reconstruction instruction: setting an entry address in the address table of the state instruction as a target address parameter of the reconstruction instruction;

Step (32): setting a source address parameter of the refactoring instruction: setting a starting address of the rewritten interpreter as a source address parameter of the refactoring instruction;

Step (33), setting a byte number parameter of the refactoring instruction: setting a capacity of the rewritten interpreter to a byte number parameter;

Step (34): Constructing a reconstruction instruction: constructing a reconstruction instruction of the state instruction according to the target address parameter, the source address parameter, and the byte number parameter.
A method of reconstructing a reconfigurable numerical control system according to claim 9, wherein said step (4) comprises the steps of:

Step (41), setting a target address parameter of the reconstruction instruction: placing the switch The entry address in the address table of the instruction is set as the target address parameter of the reconstruction instruction;

Step (42): setting a source address parameter of the refactoring instruction: setting a starting address of the rewritten interpreter as a source address parameter of the refactoring instruction;

Step (43), setting a byte number parameter of the refactoring instruction: setting a capacity of the rewritten interpreter to a byte number parameter;

Step (44): Constructing a reconstruction instruction: constructing a reconstruction instruction of the switch instruction according to the target address parameter, the source address parameter, and the byte number parameter.