Robust fault tolerant attitude control for spacecraft under partial loss of actuator effectiveness

A method of robust fault tolerant attitude control, based on adaptive sliding mode control is proposed for an on-orbiting spacecraft in the presence of partial loss of actuator effectiveness and external disturbance. In this approach, adaptive technique is employed to estimate the minimum value of actuator fault, and a sliding mode attitude controller is then designed to achieve fault tolerant control and external disturbance rejection. For the designers, the real minimum value of the fault is not required to be known in advance exactly, and the great robustness to fault is guaranteed. The simulation results of an application to spacecraft attitude adjustment maneuver show that great fault tolerant capability can be achieved even under partial loss of actuator effectiveness.