光学 精密工程, 2017, 25 (10): 2627, 网络出版: 2017-11-24
地基大口径望远镜伺服系统的抗扰动设计
Disturbance rejection control for large ground-based telescope
地基望远镜 扰动抑制 线性自抗扰控制 交流永磁同步电机 抗饱和 低速性能 ground-based telescope disturbance rejection linear active disturbance rejection control permanent magnet synchronous motor anti-windup low-speed performance
摘要
针对地基大口径望远镜伺服系统的抗扰动问题, 提出了一种抗扰动控制算法。该算法采用双闭环控制结构: 内环为高带宽的电流环, 采用PI控制器; 外环为速度环; 采用线性自抗扰控制器, 通过线性扩张状态观测器辨识出系统扰动, 然后将该扰动前馈到系统控制量中去, 构成复合校正系统。为解决大动态输入引起的控制器饱和问题, 状态观测器的输入控制量加入了抗饱和控制算法, 保证了系统的稳定性和良好的动态特性。仿真和实验结果表明: 与传统的PI控制器相比, 引入抗饱和功能的自抗扰控制器在高低速均可以获得良好的动态性能; 在低速平稳跟踪实验中, 速度波动误差(RMS)由0.000 68 (°)/s降低到0.000 32 (°)/s。实验结果证明提出的方法能够有效提高伺服系统抗扰动能力和速度跟踪的平稳性。
Abstract
An improved disturbance rejection control algorithm was proposed to overcome the velocity fluctuation caused by the disturbance torque in a large ground-based telescope. The algorithm consists of two closed-loop structures, an inner high-bandwidth current loop and an outer speed loop. The inner current loop is a PI controller. The outer loop is a speed controller adopting the linear active disturbance rejection controller. For the speed loop, an extended state observer is used to estimate the system disturbances, and the estimated disturbance is fed into the control system to form a composite correction system. To solve the problem of controller saturation caused by the large dynamic input, an anti-windup control algorithm was induced the input of the extended state observer to guarantee the stability and good dynamic characteristics of the system. The simulation and experimental results show that linear active disturbance rejection controller with anti-windup achieves fast response without overshoot at both high or low speeds as compared with the PI controller. In a low speed smoothing experiment, the algorithm improves the RMS value of speed error from 0.000 68(°)/s to 0.000 32(°)/s. Experimental results demonstrate that the proposed algorithm effectively reduces the velocity fluctuation of the servo system caused by the motor torque ripple and improves its speed smooth.
王帅, 邓永停, 朱娟. 地基大口径望远镜伺服系统的抗扰动设计[J]. 光学 精密工程, 2017, 25(10): 2627. WANG Shuai, DENG Yong-ting, ZHU Juan. Disturbance rejection control for large ground-based telescope[J]. Optics and Precision Engineering, 2017, 25(10): 2627.