An adaptive actuator failure compensation scheme for spacecraft

An adaptive actuator failure compensation scheme is developed using a direct adaptive control method, for attitude tracking control of a spacecraft with redundant actuators subject to uncertain failures whose patterns, values and time instants are unknown. The design method is to estimate the failure parameters first and uses the parameter estimates to construct the feedback control law. The control law calculation is done simultaneously with parameter estimation without explicit failure detection. Illustrative simulation results of an application to a spacecraft model show that the desired system performance are achieved in the presence of the actuator failure uncertainties.