| With the continuous development of the manufacturing industry,especially the high-end manufacturing industry,the speed and precision of the control system are increasingly demanding.Permanent magnet synchronous linear motor(PMLSM)is a driving device that can directly output linear motion.It has the significant advantages of fast response speed,high precision and high reliability.It has replaced the traditional rotating motor in many linear motion occasions requiring small displacement,high speed and high precision,such as high-grade CNC machine tools.However,the simplification of the motor structure will lead to the external disturbance directly acting on the motor itself.At the same time,many nonlinear factors exist in the operation of the motor,such as parameter change,friction force,ripple thrust,etc.,will directly affect its control performance.Although the traditional PID control can realize the positioning control of PMLSM,its performance in tracking accuracy and antiinterference is not good enough to meet the requirements of high precision,strong robustness and fast response.Therefore,it is very important to design a controller with good performance to ensure the tracking performance of permanent magnet synchronous linear motor.Aiming at the problem of position tracking control of PMLSM,this paper adopts the research method of "theoretical analysis + simulation modeling" and based on terminal sliding mode control theory,aiming at improving response speed and tracking accuracy.Specific work is as follows:(1)Establish the mathematical model of PMLSM.Considering that permanent magnet synchronous linear motor is a complex nonlinear system,many factors can not be accurately modeled,after making reasonable assumptions,using the method of coordinate transformation to establish the ideal situation of permanent magnet synchronous linear motor mathematical model.(2)The overall control scheme is designed as a three-closed-loop position control system based on vector control.Aiming at the requirements of high response and high precision,the selected vector control scheme is integrated,and the seven-stage SVPWM technology is combined to build the inner loop control system based on PI control.The inner loop control performance is optimized through multiple parameter setting.(3)A fast nonsingular terminal sliding mode position control method is proposed.Aiming at the problem of position control in PMLSM system,a position controller is designed based on terminal sliding mode control theory.Considering the slow response of traditional nonsingular sliding mode control,an arrival control law with implicit exponential property is designed,and a fast nonsingular terminal sliding mode controller(FNTSMC)is established.A complete proof procedure for the stability of the controller is given.The simulation experiments of two reference signals verify the effectiveness of FNTSMC,especially the fast convergence after sudden loading.(4)An adaptive fuzzy sliding mode control method(AFFNTSMC)is proposed.In order to solve the chattering problem in FNTSMC method,a fuzzy controller is designed to play the role of the symbolic function in the soft arrival control law.In order to solve the problem that the gain of the symbolic function in the arrival control law is difficult to be determined in practical application,an adaptive law of online tuning of control parameters is derived based on Lyapunov stability theory.Rigorous theoretical analysis proves the stability of AFFNTSMC.Simulation analysis shows that the proposed AFFTSMC system effectively attenuates chattering and has robust control performance and accurate tracking response to the PMLSM drive system under parameter changes and external interference... |
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