Research On Anti-interference Control Of Permanent Magnet Synchronous Linear Motor

With the development of high-performance permanent magnet materials and the increasingly sophisticated,high-speed,and intelligent requirements for high-end CNC machine tools,permanent magnet synchronous linear motors(PMLSM)have been widely used.Due to the complex structure of the motor itself and the susceptibility to load disturbances during operation,the theoretical difficulty of control design has greatly increased.Therefore,for the permanent magnet linear motor system,the study of applicable high-performance anti-jamming control algorithms has important theoretical and practical significance.This paper uses the interconnected state observer as a research tool.Aiming at the permanent magnet synchronous linear motor system with unmeasurable states and additional disturbances,the observer and controller are designed to realize the speed sensorless tracking control of the motor.The focus of the research is on the structure of the observer,the design of the controller and the robustness analysis.The main work and innovations are as follows.1.Aiming at the problem that some state variables in the PMLSM system cannot be measured,a backstepping control method based on the extended state interconnected observer is proposed.Regarding the time-varying and unmeasurable stator resistance and the total disturbance of the mechanical system as an expanded state,the system is transformed into the form of interconnected subsystems,and an expanded state interconnected observer based on the Kalman filter is designed for each subsystem.The unmeasured state of the system is estimated through the constructed observer,and then the controller is designed according to the backstepping recursion method.The motor speed tracking target is realized,and then the displacement tracking control problem is considered to further realize the motor displacement tracking target.2.Aiming at the problems of unmeasurable state variables and external disturbances in PMLSM system,a backstepping control method based on adaptive interconnected state observer is proposed.On the basis of the research in the third chapter,considering that the motor adopts the vector control mode where the shaft current is zero,an additional disturbance is introduced into the shaft voltage equation of the motor mathematical model,and the types of interference considered are more extensive.The construction of the observer chooses the stator resistance that changes with the environment as the expansion state of one subsystem,and the total disturbance of the mechanical subsystem as the expansion state of another subsystem.The external disturbance is estimated by adaptive rate,and an adaptive interconnected state observer based on Kalman filter is designed.The newly constructed observer can simultaneously estimate the unmeasurable state and the external disturbance of the system.Combined with the backstepping method,the speed tracking control under sensorless condition is realized.3.A theoretical analysis of the robustness of the observer and controller constructed in this paper is carried out.First,the existence of the observer is theoretically analyzed,and then according to the total dynamic error equation of the system,the Lyapunov function is selected to prove the convergence of the observer's observation error,and finally the backstepping method is used to design the controller.The existence analysis of the observer is the biggest difference between this article and the previous research work.By making full use of the structural information of the motor and the measurable information of some state variables,the extended state estimation part is specially constructed to ensure that the time-varying gain matrix of the extended state interconnected observer has a positive definite solution,and the existence of the observer is proved by the analysis.4.In order to verify the effectiveness of the anti-interference control algorithm of the closed-loop system,the simulation experiment of the permanent magnet synchronous linear motor control system is carried out on the matlab simulation platform,and the robustness of the two observer-controller methods is compared and analyzed.The Simulation results verify the effectiveness of the proposed observer and controller.