CN101834762B - A Network-Based On-line Monitoring Numerical Control System - Google Patents

Abstract

The invention discloses an online monitoring numerical control system based on a network architecture, which comprises a numerical control machine, an embedded online monitoring unit, a remote fault diagnosis center and a standard interface, wherein the embedded online monitoring unit is provided with an independent central processing unit which is independently arranged in the system and comprises a PC/104 bus, a signal conditioning module, a data acquisition card and an online monitoring module, so that data acquisition and online monitoring are realized, data transmission in weak coupling connection with the numerical control machine is constructed, and fault data transmission is carried out by connecting the standard interface with the remote fault diagnosis center; and the numerical control machine tool is connected with the remote fault diagnosis center through a standard interface to realize information interaction. The invention realizes the complete machine monitoring platform of the numerical control machine tool with seamless information interaction between the numerical control system and the embedded online monitoring unit, and integrally realizes the displayable state, the diagnosable fault, the predictable performance and the remote monitoring of the numerical control machine tool by using the complete machine monitoring platform as a node or a terminal of an equipment information network.

Description

A Network-Based On-line Monitoring Numerical Control System

technical field

The invention belongs to the technical field of numerical control systems in the manufacturing industry, and in particular relates to online monitoring, fault diagnosis, intelligent control and networked remote maintenance of the numerical control system.

Background technique

The improvement of manufacturing quality requirements in the field of advanced manufacturing technology has highlighted the importance of online monitoring, status identification and intelligent control technology as the basis of high-precision digital processing. Building an online monitoring software and hardware platform on the CNC system is the basis for early warning and control of various processing physical states, and then to realize the performance maintenance of the machine tool. At present, the existing online monitoring and diagnosis systems include Siemens ePS[1], which can realize the fault detection of machine tool electrical system and switch type, FANUC 18i series[2], and the cutting force monitoring of Swiss Kistler company[3], Germany ARTIS’s Tool monitoring [4] and other monitoring and diagnosis systems for single functional components. The main problems are that the traditional online monitoring equipment has the characteristics of installation complexity and external equipment due to volume constraints, while the customized special embedded monitoring module has defects such as long development cycle, poor openness and single monitoring function. , It is difficult to adapt to the development needs of the open architecture and reconfigurable functional modules of high-end CNC systems. In view of the above problems, the development of a functional modular embedded intelligent measurement and control system that has the early warning function of multi-physics information status of machine tool faults and has both reconfigurability and openness is an urgent problem to be solved in the field of fault diagnosis of CNC machine tools at home and abroad. One of the key technologies.

[1]. ePS Network Services, SIEMENS, www.automation.siemens.com/SIEMENS website.

[2] 16i/18i/2li remote and fault diagnosis system, www.bj-fanuc.com.cn/Fanuc website.

[3]. Kistler cutting tool monitoring, www.kistler.com/cn_cn-cn/441_CuttingToolMonitoring/Cutting-Tool-Monitoring.html/Kistler tool monitoring website.

[4]. SINUMERIK 810D powerline, www.automation.siemens.com/SIEMENS website.

Contents of the invention

Based on the above-mentioned defects in the prior art, the present invention proposes a network-based online monitoring numerical control system. By developing a general interface, the open numerical control system framework and the modular reconfigurable embedded monitoring unit seamlessly interact with each other. Based on the network, a CNC machine tool system with on-machine monitoring and intelligent maintenance functions is built, and the embedded status of high-end CNC machine tools can be displayed, faults can be diagnosed, performance can be predicted, and remote monitoring can be integrated. Monitoring diagnostic system.

In order to achieve the above object, the technical scheme adopted in the present invention is:

An online monitoring numerical control system based on a network architecture, including a numerical control machine tool, an embedded online monitoring unit, a remote fault diagnosis center and a standard interface, wherein the embedded online monitoring unit has a separate central processing unit and is independently set in the system , the unit includes PC/104 bus, signal conditioning module, data acquisition card and system online monitoring module:

The signal conditioning module is used to amplify and filter the sensor output voltage and current to meet the requirements of the noise reduction accuracy of the output analog signal and the A/D acquisition chip;

The data acquisition card is used to realize the A/D data conversion of multi-channel voltage and current;

The system online monitoring module is used for real-time display of the digital signal collected by the A/D and alarm and online monitoring under the corresponding fault diagnosis algorithm); and

The embedded on-line monitoring unit and the numerically controlled machine tool construct weakly coupled connection data transmission through a standardized interface provided by the TDNC-Connect transmission protocol; the on-line monitoring unit is connected to a remote fault diagnosis center through a standard interface, using TDNC-Connect transmission protocol for fault data transmission; and the CNC machine tool and the remote fault diagnosis center are connected through a standard interface, and the TDNC-Connect transmission protocol is used to realize information interaction; the TDNC-Connect transmission protocol is based on a general network communication protocol. The lightweight communication protocol of the software, which divides the transmission content and format into fault diagnosis information data flow transmission protocol and machine tool processing state information data flow transmission protocol according to the information feedback on the processing status of the CNC system; the data flow of fault diagnosis information The transmission protocol adopts the state information description method of "factory-monitoring unit-measuring point-monitoring quantity", builds the monitoring information database in the embedded online monitoring unit, numerical control system and remote monitoring system software, and realizes the measuring point information of state information type data Precise positioning; the agreement mainly includes the following four parts: (1) Monitoring start data segment: identifies the start of monitoring data, including monitoring date and monitoring time; (2) Monitoring global data segment: provides status acquisition parameter setting information , including analysis frequency, number of sampling points, gain, total number of channels, and channel parameter settings; (3) Monitoring information data section: the monitored specific machine tool status signals and waveforms; (4) Data end identification section: identifying the monitoring data packet End; the machine tool processing status information data flow transmission protocol is a transmission protocol established for fault identification information in the process of machine tool status information feedback, and its transmission objects include waveform and spectrum display data information, including the following 4 parts: (1) equipment information data The section includes: machine tool number, name, workshop location, failure time and machine tool management personnel information; (2) monitoring data index data section: processing status monitoring position measurement point number, monitoring data maximum value and alarm threshold; (3) failure mechanism Analysis data segment: fault location, cause and probability of occurrence; (4) fault maintenance report data segment: fault maintenance specific plan, maintenance plan, maintenance report.

The standard interface adopts Ethernet numerical control system field bus, Internet network or USB, serial port mode.

The embedded on-line monitoring unit is suitable for embedding in a dual-CPU structure of a DSP main processing chip and an FPGA co-processor.

The system also includes a host computer, which assigns a large number of tasks of fault diagnosis and intelligent maintenance to the host computer to make up for the limitation of the online monitoring unit's operation and processing capacity.

Compared with the prior art, the embedded on-line monitoring unit used in the present invention has a central processor independent of the numerical control system, which can ensure that the state monitoring function module and the numerical control command function module operate independently in the actual processing process, which improves the numerical control, The information processing capability of the measurement and control system ensures the real-time performance of the implementation of numerical control instructions and the online monitoring function of measurement and control; at the same time, the TDNC-Connect information interaction universal call interface adopted in the present invention emphasizes the openness of the numerical control system and has excellent portability of numerical control units. The TDNC-Connect transmission protocol realizes the information interaction between the embedded online monitoring unit and the remote fault diagnosis center, transfers a large number of tasks of fault diagnosis and intelligent maintenance to the host computer, and makes up for the limitation of the online monitoring unit’s operation and processing capacity; The above elements quickly build a CNC machine tool monitoring platform with a common interface that can realize seamless interaction between the CNC system and the reconfigurable embedded monitoring unit information, and use it as a node or terminal of the equipment information network, integratedly Realize the status display, fault diagnosis, performance prediction and remote monitoring of high-end CNC machine tools.

Description of drawings

Fig. 1 is a kind of online monitoring numerical control system structural diagram based on network framework of the present invention;

Fig. 2 is a kind of embedded online monitoring unit hardware structural diagram of the online monitoring numerical control system based on network architecture;

3 is a schematic diagram of a remote network system architecture of an online monitoring numerical control system based on a network architecture;

In the figure: 1, backup server 2, expert system 3, internet/intranet 4, remote fault diagnosis center 5, main control unit 6, machine tool n 7, machine tool 28, machine tool 19, fault information 10, bus/network cable/USB 11, Embedded online monitoring unit 12, signal conditioning unit 13, data acquisition card 14, PC/104 bus 15, CF card, hard disk interface 16, display interface 17, serial port 18 embedded motherboard 19, USB interface 20, network interface 21 backup server 22. Firewall 23. WWW server 24. Remote fault diagnosis center 25. Experts 26. Enterprise ERP 27. Equipment management information network 28. Equipment status monitoring and diagnosis network 29. Embedded online monitoring unit 30. Numerical control system 31. HUB

Detailed ways

In order to further understand the technical solution of the present invention, combined with the National Science and Technology Major Project (2009ZX04014-101-05) - "Numerical Control Machine Tool Fault Early Warning and Diagnosis Technology and Reconfigurable Monitoring and Diagnosis System Based on Functional Components" sub-project "Machine Tool Based on Independent CNC System" The specific implementation of the "Complete Machine Monitoring and Diagnosis Experimental Platform" project, with the accompanying drawings to illustrate the specific implementation method:

In Fig. 1 to Fig. 3, the structure of the online monitoring numerical control system based on the network architecture of the present invention includes: an embedded online monitoring unit 11 and a main control unit 5 of a numerical control machine tool with an independent central processing unit. During the online monitoring process, the embedded monitoring unit 11 is externally connected with multi-physical quantity sensors such as vibration, force, and current through the data acquisition card 13 and signal conditioning 12 to realize real-time monitoring of the machine tool state, and then through the PC/104 bus 14, CF card, The hard disk interface 15 and the display interface 16 store and display the monitoring data. The embedded monitoring unit is connected to the main control unit 5 and HUB 31 through the serial port 17, USB interface 19, and network interface 20, and through the TDNC-Connect information exchange general calling protocol, to realize the numerical control system based on monitoring data and fault information - embedded online monitoring Unit - Three-way communication for remote network monitoring system.

The embedded online monitoring unit diagnostic system architecture with modular reconfigurable characteristics under the open CNC system: it has a central processor independent of the CNC system. In the online monitoring of the processing process, the status monitoring function module and the CNC command function module Independent operation to ensure the real-time performance of CNC command implementation and measurement and control online monitoring functions.

The connection between the embedded online monitoring unit and the numerical control system: the monitoring information general call interface based on various transmission technologies such as Ethernet numerical control system field bus, Internet network, USB and serial port is adopted to realize the real-time transmission and interaction of the online monitoring unit and the numerical control system information , constructing a high-speed information transmission framework under the condition of weak coupling and seamless connection. The application of this information interaction method emphasizes the real-time nature of data transmission, and has the characteristics of openness and excellent portability of the measurement and control unit.

The connection between the embedded online monitoring unit and the remote network monitoring system: use the Internet to carry out information interaction with low real-time requirements such as monitoring data upload and fault diagnosis code download of the embedded online monitoring unit and the condition monitoring and diagnosis system under the network framework. The status monitoring and diagnosis system for complex equipment management under the network architecture is built with a mixed architecture of C/S and B/S. The system provides a variety of commonly used network databases for selection (such as SqlServer, Oracle, etc.), and the entire system framework can be divided into It is a three-layer network, including equipment status monitoring and fault diagnosis network based on C/S mode, equipment management information network and enterprise network based on B/S mode, and is finally built in the enterprise's ERP system.

Data transmission protocol between the embedded online monitoring unit and the CNC system and remote monitoring system: the TDNC-Connect transmission protocol, which takes the CNC system, embedded monitoring unit, and remote monitoring system as the transmission protocol service object, is based on the general network communication protocol A lightweight software-based communication protocol. According to the information feedback on the processing state of the CNC system, the protocol divides the transmission content and format into a fault diagnosis information data flow transmission protocol and a machine tool processing state information data flow transmission protocol. The data flow transmission protocol of fault diagnosis information adopts the state information description method of "factory-monitoring unit-measuring point-monitoring quantity", and builds a monitoring information database in the embedded online monitoring unit, numerical control system and remote monitoring system software to realize the status information Accurate positioning of measuring point information for type data. The agreement mainly includes the following four parts: (1) Monitoring start data segment: identifies the start of monitoring data, including monitoring date and monitoring time. (2) Monitor the global data segment: provide status acquisition parameter setting information, such as analysis frequency, number of sampling points, gain, total number of channels, and channel parameter settings. (3) Monitoring information data segment: the monitored specific machine tool status signals and waveforms. (4) Data end identification segment: identifies the end of the monitoring data packet. Machine tool processing status information data stream transmission protocol is a transmission protocol established for fault identification information in the process of machine tool status information feedback. Its transmission objects are display data information with relatively low real-time requirements such as waveforms and spectrums. It mainly includes the following 4 parts : (1) Equipment information data section: machine tool number, name, workshop location, fault occurrence time and machine tool manager information, etc. (2) Monitoring data index data segment: processing status monitoring position measuring point number, monitoring data maximum value and alarm threshold, etc. (3) Fault mechanism analysis data segment: specific fault diagnosis conclusions such as fault location, cause and probability of occurrence, etc. (4) Fault maintenance report data segment: breakdown maintenance specific plan, maintenance plan, maintenance report, etc. The data exchange protocol has two connection modes: (1) Point-to-point connection is realized on the basis of the dedicated data interface transmitted by the Ethernet network cable, and the weakly coupled seamless connection between the numerical control system and the embedded monitoring unit is realized. (2) On the basis of common data exchange interfaces such as network, USB, and serial ports, realize one-to-many star connection, and build an embedded machining center online monitoring remote maintenance system based on a digital manufacturing environment.

Construction of embedded online monitoring unit: including embedded industrial control motherboard with independent PC104 PLUS bus architecture, self-developed signal conditioning module, data acquisition card, embedded operating system XPE and online monitoring software installed on CF card, as equipment The on-site application platform of CNC machine tools for operation status monitoring, advanced signal processing, fault diagnosis, intelligent maintenance functions and remote monitoring has realized its hardware function design (data acquisition module, interface with CNC system, interface with remote fault diagnosis center, etc.) and Integration of software functions (data acquisition software, online monitoring software, communication protocol with the CNC system, communication protocol with the remote fault diagnosis center, etc.), the measurement and control unit is aimed at the force, vibration, noise, temperature comprehensive monitoring information acquisition platform built on the CNC machine tool , integrating a variety of signal processing and fault diagnosis methods, realizes diagnosis and intelligent maintenance under multi-sensor information, and ensures the high-precision and efficient operation of CNC machine tools. At the same time, through the network interface of the measurement and control unit or the CNC system and the TDNC-Connect transmission protocol, the CNC system becomes an intelligent node or terminal in the factory automation network, and the information exchange and network connection between multiple open CNC systems and the fault diagnosis network are realized. Realization of data management, expert system and remote diagnosis functions.

Claims (4)

1. An online monitoring numerical control system based on a network architecture, comprising a numerically controlled machine tool, an embedded online monitoring unit, a remote fault diagnosis center and a standard interface, wherein the embedded online monitoring unit has a separate central processing unit independently arranged on the In the system, the unit includes PC/104 bus, signal conditioning module, data acquisition card and system online monitoring module: The signal conditioning module is used to amplify and filter the sensor output voltage and current to meet the requirements of the noise reduction accuracy of the output analog signal and the A/D acquisition chip; The data acquisition card is used to realize the A/D data conversion of multi-channel voltage and current; The online monitoring module of the system is used for real-time display of the digital signal collected by the A/D and alarm and online monitoring under the corresponding fault diagnosis algorithm; and The embedded on-line monitoring unit and the numerically controlled machine tool construct weakly coupled connection data transmission through a standardized interface provided by the TDNC-Connect transmission protocol; the on-line monitoring unit is connected to a remote fault diagnosis center through a standard interface, using TDNC-Connect transmission protocol for fault data transmission; and the CNC machine tool and the remote fault diagnosis center are connected through a standard interface, and the TDNC-Connect transmission protocol is used to realize information interaction; the TDNC-Connect transmission protocol is based on a general network communication protocol. The lightweight communication protocol of the software, which divides the transmission content and format into fault diagnosis information data flow transmission protocol and machine tool processing state information data flow transmission protocol according to the information feedback on the processing status of the CNC system; the data flow of fault diagnosis information The transmission protocol adopts the state information description method of "factory-monitoring unit-measuring point-monitoring quantity", builds the monitoring information database in the embedded online monitoring unit, numerical control system and remote monitoring system software, and realizes the measuring point information of state information type data Precise positioning; the agreement mainly includes the following four parts: (1) Monitoring start data segment: identifies the start of monitoring data, including monitoring date and monitoring time; (2) Monitoring global data segment: provides status acquisition parameter setting information , including analysis frequency, number of sampling points, gain, total number of channels, and channel parameter settings; (3) Monitoring information data section: the monitored specific machine tool status signals and waveforms; (4) Data end identification section: identifying the monitoring data packet End; the machine tool processing status information data flow transmission protocol is a transmission protocol established for fault identification information in the process of machine tool status information feedback, and its transmission objects include waveform and spectrum display data information, including the following 4 parts: (1) equipment information data The section includes: machine tool number, name, workshop location, failure time and machine tool management personnel information; (2) monitoring data index data section: processing status monitoring position measurement point number, monitoring data maximum value and alarm threshold; (3) failure mechanism Analysis data segment: fault location, cause and probability of occurrence; (4) fault maintenance report data segment: fault maintenance specific plan, maintenance plan, maintenance report. 2. The online monitoring numerical control system based on network architecture as claimed in claim 1, wherein said standard interface adopts Ethernet numerical control system field bus, Internet network or USB, serial port mode. 3. the online monitoring numerical control system based on network architecture as claimed in claim 1, is characterized in that, described embedded online monitoring unit is applicable to the double CPU structure embedded monitoring unit of DSP main processing chip and FPGA coprocessor simultaneously. 4. The online monitoring numerical control system based on network architecture as claimed in claim 1, characterized in that, the system also includes a host computer, and a large number of tasks of fault diagnosis and intelligent maintenance are handed over to the host computer to make up for the operation and processing of the online monitoring unit. Capacity limitations.

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