On event‐triggered nonsmooth attitude tracking controller for a rigid spacecraft.

This article focuses on the problem of finite‐time attitude tracking control for a rigid spacecraft with event‐triggered inputs. The existing event‐based attitude control methods are developed from the smooth control law and can only provide at best Lipschitzian exponentially convergent. Because the nonsmooth control law shows a faster convergent rate and better control performance, a new event‐triggered nonsmooth attitude tracking controller is proposed through the emulation method of a continuous‐time finite‐time attitude controller. With the aid of Lyapunov theory and finite‐time stability lemma, the stability analysis of the closed‐loop system is given and the event‐triggered control system is Zeno‐free. Like the case of a continuous‐time nonsmooth attitude controller, it is proved that the event‐triggered nonsmooth attitude controller maintains a better disturbance rejection ability. Finally, some simulation results are given to verify the theoretical results. [ABSTRACT FROM AUTHOR]