Research On The Permanent Magnet Servo System Control Method For Rapid Response

Permanent magnet synchronous motor has good control characteristics,small size,high efficiency,high power density and high reliability.With the development of power electronics,computers,microelectronics and modern control technology,as well as the evolving of the design and manufacturing of permanent magnet synchronous motor,permanent magnet synchronous motor servo system has become the most widely used motors.Moreover,the permanent magnet synchronous motor servo system has become an important driving parts of CNC machine tools,LSI manufacturing equipment,aerospace,robotics and other fields,and it widely used in modern automotive industry.But while the existing permanent magnet servo products still can not meet the growing demands of industrial automation,especially for the quickly respond of permanent magnet servo system.Therefore,the thesis mainly research methods of permanent magnet servo control system to improve the dynamic response speed,and to achieve no overshoot control while improving dynamic performance,thus to solve the contradiction between the speed of response and overshoot.Firstly,the paper analyzes the research status of rapid response capability and the existing methods to improve the dynamic response speed of permanent magnet servo system;establishes the mathematical model of permanent magnet synchronous motor,and simply introduces the basic component of permanent magnet servo system;The mathematical model of current loop?speedloop and the position loop of permanent magnet servo system are established,derives the transfer function,then designs the parameter of current loop and speed loop from the transfer function.The analysis of permanent magnet servo system transfer function shows that the common position servo system has low dynamic response speed in order to ensure no overshoot or small overshoot.Secondly,aiming at the problem of the low rate of response of common permanent magnet servo system,this paper proposes feedforward control in servo system.Differential feedforward control can predict the given signal,so that it can improve the response speed by earlier response.The paper describes the basic principle of feedforward control and its application in position servo system,deduces feedforward control function of the position servo system.The thesis analyzes the common feedforward servo system can greatly improve the dynamic response performance to constant rate period given position command,but it has less effect to acceleration and deceleration position given.For this,the article further proposed the introduction feedforward control servo system with the current loop and speed loop Feedforward compensation.The article establishs its transfer function,derives the feedforward function and feedforward coefficient of model feedforward control system.Novel feed-forward control can effectively achieve fast dynamic tracking of the constant and acceleration and deceleration rate period by introducing the torque prediction compensation in the current loop.However,it shows that the feedforward control is less effect to discontinuities given position instruction through the analysis of feedforward function,and it can not restrain the overshoot of the system.Therefore,this paper establishes the differential feedback control system mathematical model and closed loop transfer function and does some qualitative analysis of its,demonstrate that the differential feedback control can effectively suppress the servo system overshoot,but also on the speed of response.Therefore,this article introduces the differential feedback control based on differential feedforward servo system.A feed-forward and feedback differential servo system mathematical model and transfer function is established,and feedforward and feedback functions of model system are derived,coefficient of determination.The analysis of the adaptive adjustment process between feedforward differential and feedback differential,shows that the newsystem can not only suppress overshoot by differential feedback in the big position signal error case,but also improve the response speed by feed-forward differential in small error condition,so as to realize the control without overshoot,solve the contradiction of response speed and overshoot.Finally,the simulation model of the design system is constructed in matlab2008a environment,and does the simulation experiments,and designs the hardware and software control platform of permanent magnet motor servo drive control system,then the proposed control strategy are verified by experiments.Simulation and experimental results verify the feasibility and validity of the analysis and design,shows that the control method has fast response speed,small overshoot,wide application range,and has great practical value.