Cross-coupled Iterative Learning Control Of Multi-axis Linear Servo System

The requirement of machining precision in industrial manufacturing is higher and higher with the improvement of production demand.In order to achieve higher precision,it is necessary to restrain the contour error of the system machining process better.For the multi-axis linear servo system,coupled iterative learning control is proposed.Through iterative learning control,the control accuracy of single axis can be improved.Cross-coupled control can realize the coordination of dynamic responses between different axes in the multi-axis linear servo system,so as to solve the problems of weak contour tracking control ability and insufficient machining accuracy in most practical production applications.Firstly,the structure of single axis linear servo system is analyzed and its model is built.According to the force of the system,the kinematic model of the linear motor is obtained,and the transfer function of the single-axis servo system is obtained through analysis.Then the factors of contour error are analyzed and various mathematical expressions of contour tracking are obtained based on different contour tracking mechanisms.The PID control is applied to the single axis to improve the control performance initially,and then the cross coupling structure is used to control the contour error of the system and then it is applied to the multi-axis,so as to solve the difference problem between the system axes.Secondly,the iterative learning control algorithm is used to make full use of the data generated by each repeated run.In order to avoid the deterioration of iterative learning effect,a filter is designed to suppress the non-repetitive disturbance in the actual system.Then the simulation results of PID control and iterative learning control are compared on the uniaxial to prove the advantages of iterative learning control.To improve the control performance of multi-axis linear servo system,the coupled iterative learning control is designed through the combination of iterative learning control and cross-coupling control,and the reliability of the coupled iterative learning control is verified by comparing the system control effect under different methods.Finally,the experimental platform of linear servo system is built,and the experimental comparison and verification are carried out on the platform.By comparing with the traditional control method,it is verified that the coupled iterative learning control can effectively suppress the error and improve the control precision of the system.The control effect has certain advantages over other traditional control methods.