repetitive learning control based on terminal sliding mode of space manipulator system with elastic base and two flexible joints
- Paper number
IAC-19,D1,IP,7,x51947
- Author
Mr. Xiaodong Fu, China, Fuzhou University
- Coauthor
Prof. Li Chen, China, Fuzhou University
- Year
2019
- Abstract
With the development of space technology, space manipulators installed in spacecraft orbit need to perform complex tasks, including repetitive tasks, such as on-orbit assembling, on-orbit capturing, cleaning up pollutions and so on. If the controller can enable the system to learn periodic reference signals independently, track or suppress periodic external excitation signals actively, and suppress the elastic vibration of the carrier and joints, the space manipulator with elastic base and two flexible joints will meet people's application needs. As an effective control strategy for high-precision motion, the research of repetitive learning control has achieved a lot of results. However, the research on repetitive learning control based on terminal sliding mode of space manipulator under the influence of base and joints elasticity has rarely been reported. In this paper, based on the system linear momentum conversation and the Lagrange equation of second kind, the dynamic equation of the space manipulator system with elastic base and two flexible joints is established. According to the singular perturbation theory, the model is decomposed into a rigid subsystem and a flexible subsystem. A repetitive learning control based on terminal sliding mode is proposed for the rigid subsystem to tracking periodic reference signals in limited time. The repetitive learning control is the feed-forward compensation section, which is designed to track the periodic reference signal. Terminal sliding mode control is a feedback part, which is designed to suppress periodic or non-periodic interference. The combination of the two control methods allows the closed-loop system to achieve better trajectory tracking accuracy. Compared with traditional controllers, this method deals with highly uncertain controlled systems with less prior knowledge. The implementation of this scheme does not require dynamic model information of the system, can track periodic signals accurately and suppress periodic or aperiodic disturbances. For the elastic vibration of the flexible subsystem, a linear quadratic optimal control scheme is adopted to suppress the vibration. Finally, Lyapunov theory is used to prove the global asymptotic stability of the closed-loop system. Through the simulation calculation, the validity of repetitive learning control based on terminal sliding mode is verified.
- Abstract document
- Manuscript document
IAC-19,D1,IP,7,x51947.pdf (🔒 authorized access only).
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