Fault-tolerant Control for Flight Systems in the Presence of Severe Actuator Failures and Input Constraints

A novel fault-tolerant control scheme is proposed in this paper, in which model reference adaptive control (MRAC) strategy is incorporated with control allocation (CA) method to cope with severe actuator failures, under the assumption that actuator redundancy is no longer available in the fault system. The CA method can redistribute the control signal to the remaining actuators based on the fault information. Besides achieving CA, MRAC can guarantee the closed-loop stability of the system, reduce performance deterioration caused by the severe failure, and track the modified reference model well. The modified reference model is utilized to compensate for the input saturation error. Simulations of a satellite launch vehicle model are given to illustrate the effectiveness of the proposed scheme.