Research On Optimization Of Control Strategy Of Permanent Magnet Ac Position Servo System

Position servo control is now widely applied to precision machine tools,industrial robots,rail transit,aerospace and other fields.Fast,accurate and reliable position tracking is the development trend of position servo control in the future.Because the industrial automation in China is developing quickly and deeply,the control performance of servo system must be improved relatively,and the traditional position servo control method can not obtain satisfactory control effect because of its relatively backward performance.Be aimed at the problem of how to enhance the response capability and positioning precision of position servo control system,the control method applied to the loop of speed and position in the system are researched deeply and optimized in this paper.Firstly,according to the requirements of improving response capability and positioning precision of the system,the control structure and control mode of position servo are studied,and the full closed-loop position servo control scheme under the torque control mode is determined.At the same time,according to the background requirement and the increasingly complex working condition,this paper applies the active disturbance rejection control technique(ADRC)to the position servo system,and carries on the detailed theoretical research and analysis to the algorithm.Secondly,the mathematical model of permanent magnet synchronous motor is built,and the speed loop linear active disturbance rejection controller is established based on the model.The speed loop controller is improved from the following two aspects.Firstly,because the standard extended state observer has low utilization rate of speed observation error,a new extended state observer with observation error proportional feedback is proposed by improving its structure.Secondly,the model reference adaptive algorithm is studied and used in the system inertia identification to adjust the gain parameter b in the speed loop ADRC in real time,so as to solve the problem that the inertia error affects the dynamic performance of the system.The simulation results show that the improved extended state observer can improve the disturbance observation performance of the speed loop controller,and the controller can also show stable control effect in the application field of inertia change or unknown through inertia identification and compensation method.Then,a linear ADRC of position loop based on a improved extended state observer is designed,and a complete position servo control system is constructed.The system is simulated and analyzed in Matlab/Simulink environment.The results turn out that compared with the ordinary control strategy,the proposed control strategy can effectively make the system have higher performance in the aspects of positioning precision,response capability and stability.Finally,taking the linear sensor detection platform as the control object,the position servo control system is designed and established both in aspect of hardware and software.According to the hardware design scheme of the system,the key components and the related hardware circuit are selected and designed.The software design is to realize relevant function and design a interface to control platform conveniently and visually in Lab VIEW environment.The experiments to examine the control method studied in this paper is carried out on the platform,and results turn out that the proposed control strategy applied to AC position servo system is feasible and valid.