Discrete Active Disturbance Rejection And Backstepping Control Strategy For Permanent Magnet Synchronous Motor Servo System

Servo system is one of the core components of advanced NC machine tools and industrial robots.With the rapid development of modern control technology,digital signal processing and power electronics technology,AC servo system is slowly replacing the position of DC servo system in many control fields.Permanent magnet synchronous motor(PMSM)has many advantages,such as high-power efficiency,small heat generation and small size,so it is widely used in servo system.However,PMSM is also a non-linear,strongly coupled multi-variable system,which requires high control algorithm.Therefore,the application of advanced control strategy in permanent magnet synchronous motor AC servo system is the development direction of current high-performance servo system.This paper mainly studies a control strategy of permanent magnet synchronous motor servo system based on Active Disturbance Rejection Control(ADRC).In order to improve the accuracy and anti-jamming ability of servo system,a new control strategy is adopted instead of the traditional control method.Aiming at the speed and current control system of double closed-loop and position control system of three closed-loop,combined with the mathematical model of PMSM,the ADRC controller and its algorithm of current inner loop and speed loop in double closed-loop are designed.In the three closed-loop position control system,ADRC controller and adaptive backstepping method are adopted.Firstly,based on the coordinate transformation of PMSM,the mathematical model in synchronous rotating coordinate d-q system is selected as the follow-up application.Through the analysis of three mathematical models,the mathematical model in synchronous rotating d-q coordinate system is selected as the follow-up application,and 0di = is used as the control mode of torque current and excitation current.Taking the double closed-loop of speed and current as an example,the PMSM vector control structure is established.Through the analysis of classical PID control algorithm and its advantages and disadvantages,the ADRC is introduced.The function,structure and general algorithm of ADRC are introduced.The discrete algorithm is introduced and analyzed.Based on the speed and current double closed-loop vector control and ADRC algorithm,a speed and current double closed-loop PMSM speed control system based on discrete ADRC controller is designed.Starting from the algorithm,the current loop ADRC controller,the first-order speed loop discrete ADRC and the second-order speed loop discrete ADRC are designed respectively,which lay the foundation for computer simulation.Then,ADRC and traditional PID control are applied to PMSM speed control system respectively,and the simulation results verify the advantages of ADRC.Finally,the three-loop position control system is adopted,and the PMSM position loop ADRC control strategy is designed.For the three-loop system,ADRC combined with adaptive backstepping control strategy is adopted.The position outer loop uses ADRC of the first-order system to get the desired speed signal.The adaptive backstepping method is used to realize the asymptotic tracking of the speed and obtain the desired axial current.Then the step-by-step design is carried out.The actual control of the system is estimated by the adaptive method.Changes in load.The simulation results show that the system has fast dynamic response,high steady-state accuracy,no overshoot,smooth speed and strong robustness of position control system.