High-speed And High-precision Controller Research Of Permanent Magnet Synchronous Linear Motor

Permanent magnet synchronous linear motor is the core component of automation equipment,and its control performance determines the efficiency and accuracy of automation equipment.How to realize the high-speed and high-precision control of permanent magnet synchronous linear motor has become a hot research topic at present.At present,the control strategies of permanent magnet synchronous linear motors mainly include PID control,sliding mode control,adaptive control,fuzzy control,robust control,neural network control and so on.Permanent magnet synchronous linear motor system is a nonlinear,multi-variable,and strongly coupled complex system,which is easily affected by various uncertain factors such as system parameter changes,friction disturbances,load disturbances,and end effects.The sliding mode control is essentially a special nonlinear control.Its control method is to constantly change according to the current state variables,forcing the response curve to track the planning curve well,and it has the advantages of fast response speed,insensitive to parameter changes and external disturbances,and easy to implement.According to the characteristics of permanent magnet synchronous linear motor,combined with the advantages of sliding mode control,this thesis makes theoretical research and experimental analysis on motion planning and servo system of permanent magnet synchronous linear motor.The main research contents of this thesis are as follows:（1）The development and application status of linear motors at home and abroad are studied and analyzed,and the common control strategies are summarized.This thesis introduces the structural characteristics and working principle of permanent magnet synchronous linear motor,the core component of automation equipment,and establishes the mathematical model of permanent magnet synchronous linear motor in the dq synchronous rotating coordinate system.After comprehensively analyzing the characteristics of common vector control strategies,select i_d=0 control method.（2）Aiming at the impact and residual vibration problems of high-speed point-to-point motion of automation equipment,typical motion planning is analyzed and studied to obtain motion planning suitable for high-speed and high-precision motion.Through the analysis and comparison of several typical motion planning curves and the calculation amount of their expressions,considering the calculation amount and the characteristics of the control card,the fourth-order S-shaped motion planning is selected,and the characteristics and the position,velocity,acceleration and jerk expressions of the fourth-order S-shaped motion planning are analyzed.（3）By analyzing and studying the characteristics of common sliding mode surfaces and reaching laws,and according to their shortcomings,a global fast non-singular terminal sliding mode controller is designed.In the simulink environment of MATLAB,the servo system of PMLSM is built.Through simulation analysis,compared with the traditional sliding mode controller,it is verified that the global fast non-singular terminal sliding mode controller has fast response speed,good tracking performance and strong robustness.At the same time,the method of suppressing chattering phenomenon of sliding mode control is analyzed and studied.In this thesis,the sigmoid function is used to replace the sign function.Through simulation and analysis,it is verified that the sigmoid function can well suppress the inherent chattering phenomenon of sliding mode control.At the same time,the parameter a of the sigmoid function is compared with different values,so as to obtain the optimal value of the parameter a.（4）The global fast non-singular terminal sliding mode controller has good control effect only when the external disturbance is determined.The control effect needs to be improved because of internal uncertain factors and time-varying external disturbance.An adaptive backstepping sliding mode controller is designed.Through simulation analysis,compared with the global fast non-singular terminal sliding mode controller,it is verified that the adaptive backstepping sliding mode controller has fast response speed and strong robustness,and is well suited for high-speed and high-precision applications.（5）Motion platform is built a to verify the designed controller.The motion planning algorithm and control algorithm are written in C language under the software Cross Core Embedded Studio environment,and the compiled dlm file is loaded into the DSP of the control card to realize motor control.At the same time,the platform debugging software is written based on the MFC of the Visual Studio 2019 development environment.Through the analysis of experimental results,it is verified that the response performance and positioning time of the adaptive backstepping sliding mode controller are better than those of the global fast non-singular terminal sliding mode control,the adaptive non-singular terminal sliding mode control;the response performance and positioning time of the adaptive backstepping sliding mode controller for long-distance motion and short-distance motion are both better than those of three closed-loop PID control commonly used in industry.