Discrete-time low-computation spacecraft attitude tracking control algorithm design considering actuation stiff constraints

In this paper, the attitude tracking control of spacecraft has been investigated by taking into account the input saturation constraint and an oscillatory dynamic model for the actuators. A dual-mode control scheme is presented, which has a low computational cost. The command signals are calculated by defining power reaching laws and reference filtering method. For this purpose, a new projection operator is used to determine the best possible references based on system and actuator dynamics and saturation constraints. The Lyapunov stability of the closed-loop system as well as the convergence of the filtered references to the desired references were analyzed. The dual-mode-based command signals have been determined based on minimizing the one-step predictive attitude error by combining the two controllers. The efficacy of the algorithm for tracking control has been demonstrated through numerical simulations.