精密运动平台宏微控制系统的设计

Dual-stage actuator control system design for precision motion platform

基于高动态精密伺服运动双台系统模型提出一种非线性宏微控制方法。该方法采用长行程直线电机宏动跟随音圈电机高精密微动的驱动方式,并引入扩张状态观测器。系统在定位误差较大时,采用近似时间最优控制律的轻阻尼宏动台,以允许的最大速度快速响应,在接近目标位置后,再用采用复合非线性反馈控制律的重阻尼微动台来补偿宏动台超调引起的位置偏差,最终实现系统快速高精度的定位。通过扩张状态观测器观测系统的动态变化,补偿系统中的各种扰动,减小系统的稳态跟踪误差。研究结果表明:该方法改善系统的动态性能和抗干扰能力,提高系统的定位精度。

A nonlinear macro and micro control method for high dynamic precision servo dual-stage actuator （DSA） system was presented. An nm-level positioning precision is required by using macro movement of long stroke linear motor and high-precision micro movement of voice coil motor, and the introduction of extended state observer. When the position error of the system is large, the primary actuator controller is used to yield a closed-loop system with a small damping ratio for a fast rise time and certain allowable overshoot by the frame work of proximate time optimal control （PTOC）. Then, a composite nonlinear feedback （CNF） control law was designed for the secondary actuator to reduce the overshoot caused by the primary actuator as the system output approaches the setpoint, and ultimately achieve the purpose of fast and high-precision positioning for the system. The extended state observer （ESO） was designed to estimate the unknown velocity and compensate the disturbance in servo systems, thus effectively removed the static error. The proposed control method was applied to an actual DSA positioning system. The experimental results demonstrate that our approach can improve the dynamic performance and the anti-jamming capability of the system, and enhance the control precision.