Research On High Performance Permanent Magnetic Linear Synchronous Motor Servo System

The high-performance servo system is an important part of high-end equipment such as lithography machines and CNC machine tools.Intelligent,networked,high-speed and high-precision control are its main development directions.In recent years,servo systems using permanent magnet linear synchronous motors as actuators have been widely used in linear motion applications.However,problems such as end effects,cogging effects,transmission delay,and uncertain disturbances make it difficult for such systems to meet high-performance control requirements.Therefore,the research of high-performance linear servo systems has attracted the attention of many scholars.For the speed servo system of permanent magnet linear synchronous motor,this paper proposed a speed-current closed-loop method with feedforward and feedback control.By introducing a pseudo-derivative feedforward-feedback regulator in the speed loop and using a second-order sliding mode algorithm in the current loop,a thrust disturbance observer is constructed to feedforward compensate the current loop.Speed control system with smaller dynamic drop and shorter recovery time is realized,so the speed control performance of permanent magnet linear synchronous motors is improved.Aiming at the problems of delayed response and easily lead to overshoot in the traditional three-loop position servo system,a position-current two-loop control system was designed.The composite position controller combining PD regulator with feedforward and differential negative feedback is studied,and the influence of the differential negative feedback gain parameter on the linear servo system is analyzed.A two-loop servo system with small overshoot and fast dynamic response is realized,which has great application value in point-to-point motion control occasions with low speed control requirements.Aiming at the networked control of the position servo system,a dual linear motor linkage control scheme based on EtherCAT communication was proposed.With the detailed analysis of the EtherCAT distributed clock compensation algorithm,three position control modes were designed.A dual-axis control system that has the merit of high real-time and good synchronous/alternative response performance is realized,which is suitable for applications that require high speed response and high control accuracy.The effectiveness of the proposed method was verified by the the relevant simulation and experimental results.