CN116477479A - A load attitude recognition method and system for lifting equipment - Google Patents

Abstract

The invention provides a lifting equipment load gesture recognition method and system, and belongs to the technical field of lifting equipment load gesture recognition. In the process of hoisting a load by hoisting equipment, in order to perform anti-swing control on the load, a load posture needs to be obtained. At present, the mechanical sensor is used for acquiring the load gesture, so that the problems of steel wire rope twisting, guide wheel clamping stagnation and the like exist, and the load gesture acquisition is influenced. In the hoisting process, the hoisting point is used as an origin to determine a hoisting point coordinate system, and the rotation angle of the load when the load rotates around the hoisting point coordinate system is obtained, so that the position of the load in the hoisting point coordinate system is determined. And then, the rotation transformation of the position between the two coordinate systems can be realized by utilizing the included angle between the coordinate axes corresponding to the control coordinate system and the lifting point coordinate system, so that the load position under the lifting point coordinate system is converted into the control coordinate system, and the load posture is obtained. According to the invention, no additional mechanical connection structure is required, the problems of mechanical structure clamping stagnation and the like are avoided, and the safety recognition of the load gesture can be realized.

Description

A load attitude recognition method and system for lifting equipment

technical field

The invention provides a hoisting equipment load attitude recognition method and system, belonging to the technical field of hoisting equipment load attitude recognition.

Background technique

In the process of offshore hoisting, due to the influence of uncertain factors such as sea waves and sea wind on the base of the lifting equipment, the hoisted object (that is, the hoisted object, also called the load) continues to sway irregularly, which seriously affects the safety of the hoisted object and the operator. In addition, the offshore environment is complex, and it is difficult to meet the daily work efficiency if the load is lifted when the waves and sea wind are relatively small. Therefore, a load attitude recognition method is needed to calculate the load attitude in real time, and then according to the load attitude, control the actuator action of the offshore lifting equipment through a control algorithm to perform anti-sway control, thereby solving the problem of load swing during the hoisting process and improving the safety and speed of offshore hoisting.

The IMU attitude sensor has a three-axis gyroscope, a three-axis accelerometer and a magnetometer, which can obtain the current three-axis velocity, acceleration, angle, rotation direction and other information of the measured object, which can be used to identify the attitude of the load. At present, in the field of lifting equipment market, the IMU attitude sensor is usually used to identify the swing parameters of the base of the lifting equipment, and then control the lifting point to be relatively stationary, so as to reduce the load swing and control the load attitude to be relatively stable. However, this anti-sway control strategy lacks the measurement and identification of the load attitude, and the anti-sway control effect is poor.

The attitude recognition of existing offshore hoisting mostly uses mechanical sensors, which transmit the swing of the suspension rope to the encoder through the guide wheel to obtain the swing angle of the suspension rope, thereby indirectly obtaining the load attitude. For this reason, it is necessary to set up multiple steel wire ropes to connect with the suspension ropes. However, in actual use, problems such as wire rope strangling and guide wheel sticking often occur, which not only affect the real-time performance and reliability of data acquisition, but also affect the safety of load lifting.

In summary, for offshore hoisting equipment, there is a lack of a safe and reliable load posture recognition method for anti-sway control, resulting in low safety in the offshore hoisting process.

Contents of the invention

The object of the present invention is to provide a method and system for recognizing the load posture of a lifting device, which is used to solve the problem that it is difficult to safely recognize the load posture of the offshore lifting device during the offshore hoisting process.

In order to achieve the above object, the technical solutions and beneficial effects of the lifting equipment load attitude recognition method of the present invention include:

The invention provides a load attitude recognition method for lifting equipment, comprising the following steps:

S1. During the hoisting process of the lifting equipment, the rotation angle of the load from the initial position to the current position is obtained, and according to the rotation angle, the current position of the load is calculated to the lifting point coordinate system to obtain the position of the load in the lifting point coordinate system; the rotation angle is the angle that the load has rotated around each coordinate axis of the lifting point coordinate system, and the origin of the lifting point coordinate system is the lifting point of the lifting device, and the xoy plane of the lifting point coordinate system is parallel to the ground plane;

S2. Obtain the included angle between the corresponding coordinate axes of the control coordinate system and the lifting point coordinate system, combine the positional relationship between the origin of the control coordinate system and the lifting point coordinate system based on the angle, calculate the position of the load in the lifting point coordinate system to the control coordinate system, obtain the position of the load in the control coordinate system, and then determine the load attitude; the origin of the control coordinate system is set on the slewing mechanism of the lifting device, and determine the origin of the control coordinate system and the origin of the lifting point coordinate system according to the positions of the slewing mechanism and the lifting point on the lifting device positional relationship between them.

In the process of hoisting loads by hoisting equipment, in order to control the load against sway, it is necessary to obtain the attitude of the load. At present, when the load attitude is obtained through the mechanical sensor, there are problems such as the wire rope being strangled and the guide wheel stuck, which affect the acquisition of the load attitude. During the hoisting process, the invention takes the lifting point as the origin, determines the lifting point coordinate system, and obtains the rotation angle when the load rotates around the lifting point coordinate system, thereby determining the position of the load in the lifting point coordinate system. Then, using the included angle between the corresponding coordinate axes of the control coordinate system and the lifting point coordinate system, the rotational transformation of the position between the two coordinate systems can be realized, and the translation transformation of the position between the two coordinate systems can be realized by using the positional relationship between the origin of the control coordinate system and the origin of the lifting point coordinate system. The present invention does not need to set up an additional mechanical connection structure, avoids problems such as mechanical structure clamping, and can realize safe identification of the load attitude.

Further, in step S1, the projected position of the load on the xoy plane of the lifting point coordinate system is determined according to the rotation angle and the length of the suspension rope obtained in advance, and in step S2, the projected position is solved in the control coordinate system to obtain the position of the load in the control coordinate system.

The position of the load in the lifting point coordinate system is projected on the xoy plane of the lifting point coordinate system through the length of the lifting rope and the rotation angle, and then the projected position is calculated into the control coordinate system to obtain the load posture. The calculation process is simple and easy to implement.

Further, the projection position is determined by the following formula:

In the formula, (x _p , y _p ) represents the coordinates of the projection position p, L represents the length of the lifting rope, α represents the angle that the load has rotated around the x-axis of the lifting point coordinate system, β represents the angle that the load has rotated around the y-axis of the lifting point coordinate system, and θ _z represents the angle that the load has rotated relative to the z-axis of the lifting point coordinate system at the current position.

A set of specific formulas are provided to solve the coordinates of the projected position, which is convenient for calculation.

Further, a reference coordinate system is also set, the reference coordinate system coincides with the origin of the control coordinate system, and the reference coordinate system is parallel to the corresponding coordinate axes of the suspension point coordinate system; using the predetermined positional relationship between the origin of the suspension point coordinate system and the origin of the control coordinate system, the projected position is calculated into the reference coordinate system to obtain the position of the load in the reference coordinate system, and then the position of the load in the reference coordinate system is solved to obtain the position of the load in the control coordinate system by using the angle between the control coordinate system and the corresponding coordinate axes of the suspension point coordinate system .

Set a reference coordinate system whose origin coincides with the origin of the control coordinate system, and whose coordinate axis is correspondingly parallel to the coordinate axis of the lifting point coordinate system. According to the mechanical structure of the lifting equipment, the positional relationship between the lifting point coordinate system and the origin of the control coordinate system can be determined in advance, so that the relationship can be used to calculate the projected position to the reference coordinate system, which is equivalent to translation transformation, and then use the position of the load in the reference coordinate system to solve it in the control coordinate system. The calculation process is simple.

Further, use the following formula to calculate the position of the load in the reference coordinate system:

In the formula, Indicates the position of the load in the reference coordinate system, /> Indicates the projected position of the load in the lifting point coordinate system, /> Indicates the positional relationship between the origin o of the hanging point coordinate system and the origin O of the control coordinate system.

Provide a set of specific formulas to realize the calculation of the projection position between the hanging point coordinate system and the reference coordinate system, which is simple to calculate and easy to implement.

Further, project the position of the load under the control coordinate system on the XOY plane of the control coordinate system to obtain the load posture.

In order to realize the real-time recognition of the load attitude, it is necessary to obtain the real-time projected coordinates of the load centroid in the control coordinate system. Therefore, the position of the load in the control coordinate system is projected on the XOY plane of the control coordinate system to obtain the load attitude.

Further, the load attitude is calculated by the following formula:

where (x _pt , y _pt ) represents the attitude of the load, Indicates the position of the load in the reference coordinate system, and α _K , β _K and θ _K represent the included angles between the control coordinate system and the corresponding coordinate axes of the reference coordinate system, respectively.

A set of specific formulas are provided to determine the load posture, which is simple to calculate and easy to implement.

Further, the rotation angle described in step S1 is obtained through an attitude sensor arranged on the load, and the included angle described in step S2 is obtained through an attitude sensor arranged on the slewing mechanism.

Further, the attitude sensor is an IMU attitude sensor.

The present invention also provides a load attitude recognition system for lifting equipment, including a controller, and at least one attitude sensor arranged on the load and at least one attitude sensor arranged on the slewing mechanism of the lifting equipment, the controller is connected with the attitude sensor to obtain data collected by the attitude sensor, and the controller executes instructions to realize the above-mentioned method for recognizing the load attitude of the lifting equipment.

Description of drawings

Fig. 1 is the structural representation of hoisting equipment among the present invention;

Fig. 2 is a block flow diagram of a method for recognizing a load posture of a lifting device in the present invention;

Fig. 3 is a schematic diagram of the motion state of the load center of mass in the present invention;

Fig. 4 is a schematic diagram of coordinate system rotation in the present invention;

Fig. 5 is a schematic diagram of load posture transformation in the present invention.

In the figure: 1 is a base, 2 is a slewing mechanism, 3 is a pitching mechanism, and 4 is a boom.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Embodiment of the load attitude recognition method for lifting equipment:

As shown in Figure 1, the offshore lifting equipment includes a control system, a base 1 and an actuator. The actuator includes a slewing mechanism 2, a pitching mechanism 3, and a boom 4, etc. The offshore lifting equipment controls the actuator through the control system to complete the steps of slewing, walking, pitching, compensation and hoisting to realize load hoisting.

In order to realize the real-time identification of the load posture, it is necessary to obtain the real-time projected coordinates of the center of mass of the load under the control coordinate system. The control coordinate system has a relatively fixed relationship with the actuator of the lifting equipment. The next action of the actuator can be calculated through the projection coordinates, and the actuator is driven to compensate, thereby reducing the swing of the load during the hoisting task.

Before implementing the lifting equipment load attitude recognition method of the present invention, two IMU attitude sensors need to be arranged on the offshore lifting equipment, wherein one IMU attitude sensor is installed on the load, called the load attitude sensor, and the load attitude sensor is installed horizontally near the center of mass of the load. The load coordinate system is determined by the load attitude sensor, and the x-axis, y-axis and z-axis of the load attitude sensor are the x-axis, y-axis and z-axis of the load coordinate system. Another IMU attitude sensor is installed in the control coordinate system that needs to be established, called the control coordinate system sensor. The control coordinate system sensor is installed horizontally at the center of the slewing mechanism and rotates with the slewing mechanism. The x-axis, y-axis and z-axis of the control coordinate system sensor are the x-axis, y-axis and z-axis of the control coordinate system.

The IMU attitude sensor can realize the recognition of the attitude of a single measured object, and can obtain the angle, velocity and acceleration of the measured object in the three directions of x-axis, y-axis and z-axis. According to the working principle of the IMU attitude sensor, the zero position of the z-axis rotation of the sensor (that is, the zero-degree direction of the z-axis) is determined by the geomagnetic field, and the zero-degree direction of the z-axis is the direction in which the geomagnetic field of the current location points to true north. After the load attitude sensor and the control coordinate system sensor are installed and calibrated according to the geomagnetic field, within the working range of the lifting equipment, when the z-axis rotation angles of multiple IMU attitude sensors are consistent, the x-axis and y-axis directions of each IMU attitude sensor are consistent. Therefore, when the load attitude sensor changes position following the load, the z-axis rotation angle of the load coordinate system can be determined through the geomagnetic field. According to the complexity of the equipment, sometimes three or more IMU attitude sensors are needed to recognize the load and the attitude of the equipment itself. The principle is the same as the system composed of two IMU attitude sensors in the scheme, except that multiple coordinate transformations are required in the middle process. The transformation is based on the data of the IMU attitude sensors and their installation positions on the equipment.

As shown in Figure 2, the hoisting equipment load attitude recognition method of the present invention includes the following steps:

1. As shown in Figure 3, take the hoisting point o of the lifting equipment as the origin, establish the hoisting point coordinate system: o-xyz coordinate system, and its xoy plane is parallel to the ground plane. p ₀ is the position of the center of mass of the load at time t ₀ , that is, the initial position, and p ₁ is the position of the center of mass at time t ₁ , that is, the current position. o ₀ -x ₀ y ₀ z ₀ is the coordinate system of the load at time t ₀ , o ₁ -x ₁ y ₁ z ₁ is the coordinate system of the load itself at time t ₁ , and the load has rotated a certain angle from time t ₀ to time t ₁ . Therefore, during the load hoisting process, the x-axis rotation angle α, y-axis rotation angle β, and z-axis rotation angle γ can be obtained in real time through the load attitude sensor when the load rotates.

At the same time, the rotation angle of the control coordinate system can also be obtained from the control coordinate system sensor, so the Z-axis rotation angle of the control coordinate system can be obtained. The control coordinate system is not parallel to the horizontal plane, and it swings synchronously with the equipment.

Combining the z-axis rotation angle γ of the load attitude sensor and the Z-axis rotation angle of the control coordinate system, the difference between the two is calculated as the relative rotation angle θ _z of the load from time t ₀ to time t ₁ .

As shown in Figure 4, the corresponding rotation matrix after the θz angle is rotated counterclockwise by the o ₀ -x ₀ y ₀ z ₀ coordinate system is:

Combined with the mechanical structure of the lifting device and the length L of the suspension rope, the coordinates (x _p , y _p ) of the projection point p of the load centroid p ₁ on the xoy plane of the o-xyz coordinate system at the current moment t ₁ can be obtained through the following relational formula.

2. Referring to Figure 5, the OX _C Y _C Z _C coordinate system is a reference coordinate system, its coordinate axes are parallel to the coordinate axes of the coordinate system o-xyz, and the origin of the OX _C Y _C Z _C coordinate system coincides with the origin of the control coordinate system. p is the projection of the current load centroid on the xoy plane of the hanging point coordinate system o-xyz.

Through the principle of space vector superposition, we can get:

The origin O of the control coordinate system is the center of the slewing mechanism, and o is the current lifting point position, so the vector can be calculated according to the geometric structure of the lifting equipment Coordinates in the reference frame OX _C Y _C Z _C. At the same time, the coordinates (x _p , y _p ) of the projection point p can be used as the vector in Figure 5 /> coordinate of.

3. p _t is the projection of p on the X _K OY _K plane of the control coordinate system, which can be used as the attitude of the load. According to the x, y, z inclination angles α _K , β _K and θ _K output by the sensor of the control coordinate system, project p onto the X _K OY _K plane of the control coordinate system to obtain the coordinates of p _t (x _pt , y _pt ), the calculation formula is:

(x _pt , y _pt ) represents the attitude of the load, Indicates the position of the load in the reference coordinate system, α _K , β _K and θ _K respectively represent the angles between the control coordinate system and the corresponding coordinate axes of the reference coordinate system.

4. During the load hoisting process, repeat the above steps 1-3 to obtain the real-time load attitude and realize the real-time identification of the load attitude in the control coordinate system.

The invention realizes the real-time identification of the load posture of the offshore lifting equipment, determines the real-time coordinates of the load in the system control coordinate system, and provides input parameters for the control system of the lifting equipment to control the motion of the actuator. After the load posture is obtained by using the present invention, the next action of the executive mechanism can be calculated by an algorithm, so as to provide reliable data support for the anti-sway control of offshore hoisting. At the same time, compared with the method in the prior art that uses a mechanical sensor to indirectly determine the load attitude, the present invention does not need to add a complicated mechanical connection structure, avoids the occurrence of problems such as wire rope strangulation, guide wheel sticking, etc., and improves the reliability and safety of load hoisting. In addition, the calculation process in the present invention is simple, the amount of calculation is small, the attitude of the load can be quickly obtained, and the real-time performance is good.

Embodiment of the load attitude recognition system for lifting equipment:

The hoisting equipment load attitude recognition system of the present invention adopts the method of setting an IMU attitude sensor on the hoisting equipment in the embodiment of the hoisting equipment load attitude recognition method, and communicates with each IMU attitude sensor through a controller to obtain the data collected by the IMU attitude sensor. The controller implements the load attitude recognition method of the lifting equipment load attitude recognition method in the embodiment of the lifting equipment load attitude recognition method by executing instructions, so as to obtain the load attitude, so as to facilitate the anti-swing control of the load. The realization of this method has been clearly introduced in the embodiment of the lifting equipment load attitude recognition method, and will not be repeated here.

Claims (10)

1. A hoisting equipment load posture recognition method, is characterized in that, comprises the steps: S1. During the hoisting process of the lifting equipment, the rotation angle of the load from the initial position to the current position is obtained, and according to the rotation angle, the current position of the load is calculated to the lifting point coordinate system to obtain the position of the load in the lifting point coordinate system; the rotation angle is the angle that the load has rotated around each coordinate axis of the lifting point coordinate system, and the origin of the lifting point coordinate system is the lifting point of the lifting device, and the xoy plane of the lifting point coordinate system is parallel to the ground plane; S2. Obtain the included angle between the corresponding coordinate axes of the control coordinate system and the lifting point coordinate system, combine the positional relationship between the origin of the control coordinate system and the lifting point coordinate system based on the angle, calculate the position of the load in the lifting point coordinate system to the control coordinate system, obtain the position of the load in the control coordinate system, and then determine the load attitude; the origin of the control coordinate system is set on the slewing mechanism of the lifting device, and determine the origin of the control coordinate system and the origin of the lifting point coordinate system according to the positions of the slewing mechanism and the lifting point on the lifting device positional relationship between them. 2. The load attitude recognition method of lifting equipment according to claim 1, wherein in step S1, according to the angle of rotation and the length of the suspension rope obtained in advance, the projected position of the load on the xoy plane of the suspension point coordinate system is determined, and in step S2, the projected position is solved under the control coordinate system to obtain the position of the load in the control coordinate system. 3. The load posture recognition method of lifting equipment according to claim 2, wherein the projection position is determined by the following formula: In the formula, (x _p , y _p ) represents the coordinates of the projection position p, L represents the length of the lifting rope, α represents the angle that the load has rotated around the x-axis of the lifting point coordinate system, β represents the angle that the load has rotated around the y-axis of the lifting point coordinate system, and θ _z represents the angle that the load has rotated relative to the z-axis of the lifting point coordinate system at the current position. 4. The load posture recognition method for lifting equipment according to claim 2, wherein a reference coordinate system is also set, the reference coordinate system coincides with the origin of the control coordinate system, and the reference coordinate system is parallel to the corresponding coordinate axes of the suspension point coordinate system; using the predetermined positional relationship between the origin of the suspension point coordinate system and the origin of the control coordinate system, the projected position is solved under the reference coordinate system to obtain the position of the load in the reference coordinate system, and then the angle between the control coordinate system and the corresponding coordinate axes of the suspension point coordinate system is used to calculate the position of the load in the reference coordinate system The position is calculated to the control coordinate system to obtain the position of the load in the control coordinate system. 5. The hoisting equipment load posture recognition method according to claim 4, wherein the position of the load in the reference coordinate system is calculated using the following formula: In the formula, Indicates the position of the load in the reference coordinate system, /> Indicates the projected position of the load in the lifting point coordinate system, Indicates the positional relationship between the origin o of the hanging point coordinate system and the origin O of the control coordinate system. 6. The load posture recognition method of lifting equipment according to claim 4, wherein the load posture is obtained by projecting the position of the load under the control coordinate system on the XOY plane of the control coordinate system. 7. The load attitude recognition method of lifting equipment according to claim 6, wherein the load attitude is calculated by the following formula: where (x _pt , y _pt ) represents the attitude of the load, Indicates the position of the load in the reference coordinate system, and α _K , β _K and θ _K represent the included angles between the control coordinate system and the corresponding coordinate axes of the reference coordinate system, respectively. 8. The load posture recognition method of lifting equipment according to claim 1, wherein the rotation angle described in step S1 is acquired by an attitude sensor arranged on the load, and the included angle described in step S2 is obtained by an attitude sensor arranged on the slewing mechanism. 9. The load attitude recognition method of lifting equipment according to claim 8, wherein the attitude sensor is an IMU attitude sensor. 10. A lifting equipment load attitude recognition system, characterized in that it comprises a controller, and also includes at least one attitude sensor arranged on the load and at least one attitude sensor arranged on the slewing mechanism of the lifting equipment, the controller is connected with the attitude sensor to obtain the data collected by the attitude sensor, and the controller executes instructions to realize the lifting equipment load attitude recognition method according to any one of claims 1-9.