title: Error-Based Observer of a Charge Couple Device Tracking Loop for Fast Steering Mirror.
abstract: The charge couple device (CCD) tracking loop of a fast steering mirror (FSM) is usually used to stabilize line of sight (LOS). High closed-loop bandwidth facilitates good performance. However, low-rate sample and time delay of the CCD greatly limit the high control bandwidth. This paper proposes an error-based observer (EBO) to improve the low-frequency performance of the CCD tracking system. The basic idea is by combining LOS error from the CCD and the controller output to produce the high-gain observer, forwarding into the originally closed-loop control system. This proposed EBO can improve the system both in target tracking and disturbance suppression due to LOS error from the CCD's sensing of the two signals. From a practical engineering view, the closed-loop stability and robustness of the EBO system are investigated on the condition of gain margin and phase margin of the open-loop transfer function. Two simulations of CCD experiments are provided to verify the benefits of the proposed algorithm.
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. prettang@gmail.com.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. prettang@gmail.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Tang
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. chaosir1991@gmail.com.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. chaosir1991@gmail.com.|University of Chinese Academy of Sciences, Beijing 100039, China. chaosir1991@gmail.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Deng
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. Yangtao@gmail.com.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. Yangtao@gmail.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. zqfirefly@126.com.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. zqfirefly@126.com.
authors.forename: Daijun
authors.initials: D
authors.lastname: Zhong
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. renge@ioe.ac.cn.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. renge@ioe.ac.cn.
authors.forename: Ge
authors.initials: G
authors.lastname: Ren
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. huangym@ioe.ac.cn.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. huangym@ioe.ac.cn.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Laboratory of Optical Engineering, Chinese Academy of Science, Chengdu 610209, China. cyfu@ioe.ac.cn.|Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China. cyfu@ioe.ac.cn.
authors.forename: Chengyu
authors.initials: C
authors.lastname: Fu
keywords: CCD error-based observer; fast steering mirror; image sensor; light of sight error; low-rate sample; time delay