Improved Smith predictor control for fast steering mirror system

3rd International Conference on Advances in Energy, Environment and Chemical Engineering

能源学;生态环境科学;化学工业

Cao, Zheng^1,2,3 ; Chen, Jing^1,2,3 ; Deng, Chao^1,2,3 ; Mao, Yao^1,2 ; Li, Zhijun^1,2

Key Laboratory of Optical Engineering, Chinese Academy of Sciences, Chengdu

610209, China^1

Institute of Optics and Electronics, Chinese Academy of Science, Chengdu

610209, China^2

University of Chinese Academy of Sciences, Beijing

100039, China^3

关键词: Dual closed loops;    Fast steering mirror;    Fiber optic gyroscopes;    Mechanical resonance;    Regulating systems;    Smith predictor control;    Tracking control systems;    Tracking performance;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/69/1/012085/pdf
DOI  :  10.1088/1755-1315/69/1/012085

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

In this paper, a novel Smith predictor control strategy improved by a high bandwidth inner loop for fast steering mirror (FSM) tracking control system based on a charge-coupled device (CCD) and rate sensor is proposed. A high bandwidth velocity closed-loop constructed by a fiber-optic gyroscope is utilized to provide a robust controlled plant for the Smith predictor controller. Usually, due to the mechanical resonances and time delay induced by a low CCD sampling rate, the tracking performance of FSM system is insufficient when suffering uncertain input command. Therefore, the Smith predictor control, which is famous for its delay-free characteristic and suitable for regulating systems with an excessively long time delay, is recommended to compensate for the CCD time delay. However, the classical Smith predictor is sensitive to plant parameter variations, which could deteriorate the stability of the control system. Thus, in order to make a robust Smith predictor, a cascaded dual closed-loop including a high bandwidth velocity inner loop is introduced to reduce the influence of plant parameter variations. The low sensitivity to parameter variation of this method shows the significant improvement of the conventional Smith predictor control. Simultaneously, the analysis of tracking accuracy and the bandwidth of the FSM system is also presented. A series of comparative experimental results demonstrate that the tracking performance of the FSM control system can be effectively improved by the proposed approach.