Abstract:

A novel time-optimal feedback control algorithm for closed-loop control of an underactuated rigid spacecraft is presented. First, the constrained trajectory is generated by direct Legendre pseudospectral method, and the feasibility of the control solutions is validated. Then, regarding the errors between the actual trajectory and the reference trajectory as variables, an error equation is constructed which can be solved by indirect Legendre pseudospectral method. Finally, the closed-loop trajectory tracking control law is obtained by on-line replanning strategy. Simulation results demonstrate that the proposed control scheme can obtain a closed-loop state feedback control law in real-time and can lead to a high precision even in the presence of initial state perturbations.