Extended state observer based output control for spacecraft rendezvous and docking with actuator saturation
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Published on: May 25, 2016
Qi Li1, Jianping Yuan1, Bo Zhang2
1National Key Laboratory of Aerospace Flight Dynamics, Xi'an, Shaanxi 710072, China; School of Astronautics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
Abstract:
This paper investigates the relative position tracking and attitude synchronization problem of a chaser spacecraft rendezvous and docking with an uncontrolled tumbling target in the presence of external disturbances and actuator saturation. By combining the extended state observer technique with backstepping control methodology, a robust output-feedback control strategy with no precise motion information of the tumbling target is proposed. Moreover, a particular Nussbaum-type function is introduced to compensate for the nonlinear terms arising for actuator saturation. Within the Lyapunov framework, it is then shown that the proposed control strategy can guarantee the relative position and attitude errors converge into small regions containing the origin. Finally, numerical simulations are carried out to verify the effectiveness of the designed control strategy.
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