Fault-tolerant control of non-linear systems based on adaptive virtual actuator

Abstract

A new adaptive fault-tolerant control architecture for Lipschitz non-linear systems is developed. Specifically, the proposed approach involves a novel adaptive virtual actuator which is inserted between the faulty plant and the nominal controller to hide faults and disturbances from the nominal controller. The envisaged adaptive virtual actuator does not require any information about the nominal controller nor does it require a separate fault detection, isolation and identification unit. Moreover, it can tackle loss of effectiveness and time-varying additive actuator faults as well as an external disturbance, and in addition to the stability of the closed-loop system, it also guarantees that the difference between the states of the nominal and the faulty systems tend to zero. Simulation results corresponding to the lateral directional dynamics of an aircraft demonstrate and illustrate the effectiveness of the proposed adaptive virtual actuator.