Adaptive robust actuator fault compensation for linear systems using a novel fault estimation mechanism

摘要

This paper investigates the problem of adaptive fault-tolerant control for a class of linear systems with time-varying actuator faults. The outage and loss-of-effectiveness fault cases are covered. An active fault compensation control law was designed in two steps. Firstly, the time-varying fault parameters were estimated based on a novel adaptive observer. Compared with the traditional adaptive observer, the actuator fault estimations are faster and the high-frequency oscillations can be attenuated effectively. Such oscillations are usually caused by increasing the gains of adaptive laws to deal with abrupt changes in system dynamics. Then, based on online estimations of the fault parameters, an adaptive fault-tolerant controller was constructed to compensate for the loss of actuator effectiveness and to eliminate the effect of fault estimation error. The asymptotic stability and an adaptive H performance of a closed-loop system can be guaranteed, even in the case of actuator faults and disturbances. Simulation results are given to verify the effectiveness and superiority of the proposed method. Copyright (c) 2015 John Wiley & Sons, Ltd.