Refined Antidisturbance Attitude Control for Microsatellite With Actuator Dynamics Under Matched and Mismatched Disturbances

Multiple disturbances including reaction wheel back electromotive force and solar panels vibration seriously restrict the improvement of microsatellite attitude control accuracy. Notably, these disturbances are physically multisource, mathematically heterogenous, affecting the system dynamics via isomeric channels. In response, a refined antidisturbance attitude control scheme is proposed. First, the microsatellite attitude deep coupling dynamics model is constructed by considering reaction wheel dynamics and multiple disturbances. Second, a linear disturbance observer (DO) is developed for back EMF, and an unknown frequency DO is designed for solar panels vibration to achieve accurate estimation. Based on the refined disturbances estimation, a nonsingular fast terminal sliding mode controller is proposed to obtain high precision and rapid convergence of microsatellite attitude control system. Finally, both numerical simulations and hardware-in-loop experiments are conducted to demonstrate the effectiveness of the proposed strategy.