Adaptive non-singular fast terminal sliding mode based tolerant control for spacecraft

Finite-time convergence fault tolerant control strategies based on adaptive non-singular fast terminal sliding mode are proposed for spacecraft attitude tracking control subject to external disturbances, inertia uncertainties and actuator faults. A finite-time fault-tolerant attitude tracking controller meets the multi-constraints is developed by introducing a nonsingular fast terminal sliding mode, which can convergence in finite-time and avoid singularities. It is further shown that the controller is independent from a prior knowledge of spacecraft inertia or upper bound of external disturbances with parameter adaptations. The Lyapunov stability analysis shows that the controller designed in this paper can guarantee the fast convergence of the closed-loop system, and has a good fault tolerant performance for actuator faults under multiconstraints on external disturbances, inertia uncertainties and actuator faults. Numerical simulation has verified the good performance of the controller in the attitude tracking control.