Appointed‐time nonsingular sliding mode control of spacecraft attitude stabilization

This paper investigates the appointed-time attitude stabilization problem of a rigid spacecraft under disturbance and parametric uncertainty. A continuous sliding mode observer is presented to observe synthetical term. To circumvent singularity in terminal control, new nonsingular surface designed by employing concept switching control. Based on observation information deriving from proposed observer, an observer-based control scheme developed stabilize system within appointed time which given user. And also, undesired chattering phenomenon can be attenuated. The stability controlled proved Lyapunov criteria. simulation results show that valid.