直线电机精密定位平台轨迹跟踪控制器设计

为了实现直线电机精密定位平台的位置和速度的轨迹跟踪控制,本文基于内模控制（IMC）的基本原理,在直线电机精密定位平台参数辨识的基础上,设计了定位平台速度环的模型状态反馈（MSF）控制器和基于位置环PID和速度环MSF的级联控制器。将PID/MSF级联控制器与速度/加速度前馈控制（VFC/AFC）相结合,构成了PID/MSF+VFC/AFC的复合轨迹跟踪控制器。该复合轨迹跟踪控制器通过整定速度前馈的增益来改善位置环偏差控制的跟踪滞后现象和动态响应,增加控制系统的稳定性和伺服精度;通过整定加速度前馈的增益在不减小级联控制器位置环增益的前提下,减小速度前馈带来的超调量,提高轨迹跟踪精度。基于MATLAB/dSPACE实时仿真控制平台,实现了某直线电机平台的轨迹跟踪控制。仿真和实验结果表明,该轨迹跟踪控制器的轨迹跟踪精度为±0.028 mm,定位精度为±4 μm,满足直线电机精密定位平台轨迹跟踪控制的要求。

Design of trajectory tracking controller for precision positioning table driven by linear motor

In order to achieve the high precision trajectory tracking control of a positioning table driven by Permanent Magnetic Synchronous Linear Motor (PMSLM), This paper designs a hybrid trajectory tracking controller.The controller combines Model State Feedback (MSF) and Velocity/Acceleration Feedforward controls (VFC/AFC) to ensure the precision of a positioning table. Based on the principles of Internal Model Control (IMC) and the identified model of the positioning table, a MSF controller is proposed and the parameter calculation methods of the MSF controller are presented. Using the MSF model, a cascade PID/MSF controller is designed. The PID/MSF cascade controller is incorporated with the VFC/AFC control to construct a hybrid PID/MSF+VFC/AFC trajectory tracking controller. The VFC in the trajectory tracking controller is used to improve the velocity command response and the AFC is used to remove the overshoot induced by VFC without lowering the position loop gains. The hybrid trajectory tracking controller is implemented in the MATLAB/dSPACE real time control platform. Simulation and experimental results show that the controller can meet the requirements of precision tracking control and can achieve the tracking accuracy of ±0.028 mm and the positioning accuracy of ±4 μm for a precision positioning table driven by PMSLM.