Zhihao Zhu*, Zhi Gao, and Yu Guo
International Journal of Control, Automation, and Systems, vol. 20, no. 2, pp.411-420, 2022

Abstract : The distributed global velocity-free attitude coordination control problem for multiple formation spacecraft without unwinding phenomenon and with disturbance is investigated in this paper. Initially, a fixed-time observer is constructed to estimate the states of the virtual leader in fixed time. For the formation spacecraft with attitude-only measurements, a filter system is developed. To estimate the disturbance, a fixed-time extended state observer is proposed. With the application of the fixed-time observers and the filter system, a distributed global velocity-free attitude coordination controller is designed to grantee that the leader with time-varying trajectory can be tracked coordinately by the formation spacecraft, where the unwinding problem of the spacecraft can be avoided. In addition, a distributed velocity-free attitude coordination controller on the basis of the fixed-time extended state observer is designed to compensate the effect of the lump disturbance. Finally, the effectiveness of the proposed controller is demonstrated by numerical simulation.

Keyword : Distributed global control, filter system, fixed-time observer, unwinding phenomenon, velocity-free attitude coordination.