CN-121973195-A - Synchronous control method for cooperative robot and additional shaft

CN121973195ACN 121973195 ACN121973195 ACN 121973195ACN-121973195-A

Abstract

The invention discloses a synchronous control method of a collaborative robot and an additional shaft, which is characterized in that a smooth cam curve is generated by a method of sectioning multiple interpolations on the basis of an offline track of the collaborative robot, then an offline cam table with higher adaptation degree to the change of the track of the collaborative robot is generated after sampling design and data calculation according to the cam curve, finally, the additional shaft is subjected to synchronous control and multi-mode error compensation by feedback quantity of the collaborative robot and the additional shaft, the following performance of the additional shaft to the track of the collaborative robot is improved by a layering compensation mechanism, a dynamic error weight adjustment strategy, control quantity synthesis and anti-saturation treatment multi-aspect compensation or optimization method, synchronous control of the collaborative robot and the additional shaft is realized, synchronous control of a writing robot and the additional shaft under complex track movement can be supported, and the disturbance rejection capability and following performance in the additional shaft control process are effectively improved.

Inventors

HUANG JINGJIN
TANG ZIYUAN
HU ZHIYUAN
LUO LINGLING
LIANG JIE
LEI PEI
TU FUQUAN
WANG FEI
LIU FAMING
NIE HAIPING
LIU HUASEN
XU WENWEN
CHEN YAHUI

Assignees

成都飞机工业（集团）有限责任公司

Dates

Publication Date: 20260505
Application Date: 20260122

Claims (10)

1. A synchronous control method for a cooperative robot and an additional shaft is used for realizing synchronous control of the cooperative robot and the additional shaft and is characterized in that a smooth cam curve is generated by a method of sectioning multiple interpolations on the basis of an offline track of the cooperative robot, a cam table which is matched with track change of the cooperative robot is generated after sampling design and data calculation according to the cam curve, and the synchronous control and multi-mode error compensation method are adopted for the additional shaft by combining feedback quantity of the cooperative robot and the additional shaft and parameters in the cam table, so that the following property of the additional shaft to the track of the cooperative robot is improved from the aspects of a layering compensation mechanism, a dynamic error weight adjustment strategy, control quantity synthesis and anti-saturation treatment, and synchronous control of the cooperative robot and the additional shaft is realized.
2. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 1, comprising the steps of: Step 1, extracting a single-axis component at the tail end of an offline track of a cooperative robot to serve as a target track of an additional axis; step 2, dividing a target track into a plurality of continuous segments, and generating a smooth cam curve by adopting polynomial interpolation aiming at each continuous segment; step 3, dividing a cam curve into sub-segments according to the track characteristics of the cooperative robot, and discretizing each sub-segment into a time sequence; Step 4, calculating the motion parameters of the additional shaft at the current sampling time according to each sampling time in the time sequence, and storing the motion parameters as a cam table according to the time sequence; Step 5, calculating the motion association error of the additional shaft according to the parameters in the cam table and the real-time feedback quantity of the additional shaft, and adjusting the weight of the motion association error; Step 6, establishing a PID+MPC model to perform layered compensation on the motion association error, and then synthesizing and anti-saturation processing on the control quantity in the PID+MPC model to obtain a control strategy for the additional shaft; and 7, performing synchronous control test on the cooperative robot and the additional shaft based on a control strategy.
3. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 2, wherein the step 5 specifically comprises: step 5.1, calculating a motion association error of the additional shaft according to parameters in the cam table and real-time feedback quantity of the additional shaft; step 5.2, classifying the motion-related error into a position-related error and a speed-related error; And 5.3, when the position association error exceeds the threshold value, preferentially suppressing the position association error by increasing the position weight, and when the position association error is smaller than the threshold value, preferentially suppressing the acceleration association error by increasing the acceleration weight.
4. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 2, wherein the step 6 specifically includes: step 6.1, establishing a quick response layer PID, and carrying out dynamic weighted summation on the position association errors and the speed association errors in the motion association errors based on the quick response layer PID to obtain PID control quantity; step 6.2, establishing a prediction compensation layer MPC, and predicting the future state of the additional shaft based on the prediction compensation layer MPC to obtain MPC control quantity; and 6.3, accumulating the PID control quantity and the MPC control quantity to obtain a total control quantity, then performing anti-saturation treatment on the total control quantity, and generating a control strategy based on the total control quantity after the anti-saturation treatment.
5. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 4, wherein in the step 6.1, a weight fusion discretization model is introduced into the fast response layer PID to dynamically weight and sum the position association error and the speed association error in the motion association error, and the weight fusion discretization model is as follows: ; Wherein: Indicating the PID control amount; representing a control period; representing a proportional gain coefficient; representing an integral gain coefficient; representing the differential gain coefficient; representing a position error; Representing a speed error; represents the kth acceleration error; represents the kth-1 acceleration error; representing a position error gain factor; Representing a velocity error gain coefficient; representing the acceleration error gain coefficient.
6. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 4, wherein the step 6.2 specifically comprises: A1, inputting control quantity in a prediction compensation layer MPC, establishing a state prediction model of an additional shaft according to the control quantity, and predicting the future state of the additional shaft based on the state prediction model; a2, establishing a state objective function based on the future state of the additional shaft, and setting constraint conditions based on the control quantity amplitude and the control quantity increment for the state objective function to obtain an optimal objective function; And A3, performing quadratic programming solution on the optimal objective function, and taking the first control quantity corresponding to the solved objective function as the MPC control quantity.
7. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 4, wherein the step 6.3 specifically comprises: Step B1, accumulating PID control quantity and MPC control quantity to obtain total control quantity; Step B2, establishing an anti-saturation processing model based on the maximum output value of the additional shaft actuator, and performing anti-saturation processing on the total control quantity by adopting the anti-saturation processing model, wherein the anti-saturation processing model is as follows: ; Wherein: representing the total control amount; Representing the maximum output value of the additional shaft actuator.
8. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 2, wherein the step 7 specifically comprises: step 7.1, starting the cooperative robot, controlling the cooperative robot to move to an ith track according to a control strategy, and detecting the actual zero position posture of the cooperative robot at the moment; step 7.2, comparing the actual zero position posture with the target zero position posture when the cooperative robot moves to the ith track, if the actual zero position posture is matched with the target zero position posture, turning to 7.3, and if the actual zero position posture is not matched with the target zero position posture, re-executing the step 7.1 according to a new control strategy; step 7.3, controlling the cooperative robot and the additional shaft to start synchronously according to a control strategy, detecting the core motion state quantity of the cooperative robot and the additional shaft in real time in the motion process of the cooperative robot and the additional shaft, switching to step 7.4 if the core motion state quantity is normal, and stopping the cooperative robot and the additional shaft if the core motion state quantity is abnormal; And 7.4, synchronously moving the cooperative robot and the additional shaft until the cam table is executed, judging whether the current track where the cooperative robot and the additional shaft are positioned is the last track, ending the test if the current track is the last track, executing i+1 if the current track is not the last track, and returning to the step 7.1.
9. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 2, wherein the step 2 specifically comprises: Step 2.1, establishing a target track polynomial about the segmentation time, and establishing a dynamic boundary condition of a cam curve in a time segmentation interval; step 2.2, solving coefficients of a polynomial by combining a target track polynomial and a dynamic boundary condition; And 2.3, carrying the coefficients into a target track polynomial to obtain a cam curve.
10. The method for synchronously controlling the cooperative robot and the additional shaft according to claim 2, wherein the step 3 specifically comprises: Step 3.1, carrying out discrete division on the track of the cooperative robot based on a plurality of time periods to obtain a plurality of sub-segments; step 3.2, setting a sampling period and sampling points in each sub-segment; and 3.3, calculating a time sequence based on the sampling period and the sampling point.

Description

Synchronous control method for cooperative robot and additional shaft Technical Field The invention belongs to the technical field of industrial automation control, and particularly relates to a synchronous control method for a cooperative robot and an additional shaft. Background For flexible automatic processing tasks of large-size and complex curved surfaces, an external additional shaft is usually introduced at the action end of a traditional cooperative robot, and the processing working range is expanded through the joint movement of the cooperative robot and the additional shaft, so that the whole robot processing system can realize more complex and wider processing operation. In the moving process of the cooperative robot and the additional shaft, the cooperative robot and the additional shaft need to be synchronously controlled in order to ensure the borrowing precision and the reliability of the whole robot. For example, in the patent application with the application number of CN115922704a, the linkage control of the robot and the external shaft is only suitable for unified control of multiple types of external shafts such as a guide rail, a positioner, etc., but the mapping relationship depends on high-precision calibration, and is easy to fail in a vibration environment, and the real-time interpolation conversion increases the computational load of the controller. For example, in the patent application with the application number of CN119238481B, the control of the cooperative robot and the additional axis is based on the additional axis speed control of the motion interval duration, which improves a certain teaching efficiency and precision, but is not applicable to an application scenario of complex trajectories. Therefore, the invention discloses a synchronous control method of a cooperative robot and an additional shaft, aiming at the problems in the synchronous control process of the cooperative robot and the additional shaft in the prior art. Disclosure of Invention The invention discloses a synchronous control method for a collaborative robot and an additional shaft, which can support synchronous control of a writing robot and the additional shaft under complex track movement and effectively improve disturbance rejection capability and following performance in the control process of the additional shaft. The invention is realized by the following technical scheme: A synchronous control method for a cooperative robot and an additional shaft is used for realizing synchronous control of the cooperative robot and the additional shaft, generating a smooth cam curve by a method of sectioning multiple interpolations on the basis of an offline track of the cooperative robot, generating a cam table adapted to track change of the cooperative robot according to the cam curve after sampling design and data calculation, adopting a synchronous control and multi-mode error compensation method for the additional shaft by combining feedback quantity of the cooperative robot and the additional shaft and parameters in the cam table, and improving the following property of the additional shaft to the track of the cooperative robot from the aspects of a layering compensation mechanism, a dynamic error weight adjustment strategy, control quantity synthesis and anti-saturation treatment, thereby realizing synchronous control of the cooperative robot and the additional shaft. In order to better realize the invention, the method further comprises the following steps: Step 1, extracting a single-axis component at the tail end of an offline track of a cooperative robot to serve as a target track of an additional axis; step 2, dividing a target track into a plurality of continuous segments, and generating a smooth cam curve by adopting polynomial interpolation aiming at each continuous segment; step 3, dividing a cam curve into sub-segments according to the track characteristics of the cooperative robot, and discretizing each sub-segment into a time sequence; Step 4, calculating the motion parameters of the additional shaft at the current sampling time according to each sampling time in the time sequence, and storing the motion parameters as a cam table according to the time sequence; Step 5, calculating the motion association error of the additional shaft according to the parameters in the cam table and the real-time feedback quantity of the additional shaft, and adjusting the weight of the motion association error; Step 6, establishing a PID+MPC model to perform layered compensation on the motion association error, and then synthesizing and anti-saturation processing on the control quantity in the PID+MPC model to obtain a control strategy for the additional shaft; and 7, performing synchronous control test on the cooperative robot and the additional shaft based on a control strategy. In order to better implement the present invention, further, the step 5 specifically includes: step 5.1, calculating a motion associ