Fault-tolerant control of discrete-time LPV systems using virtual actuators and sensors

This paper introduce a new fault-tolerant control (FTC) method for discrete-time linear parameter varying (LPV) systems. Fault-tolerance is achieved without redesigning the nominal controller by inserting a reconfiguration block between the plant and the nominal controller. The reconfiguration block is realized by a virtual actuator and a virtual sensor. The signals from the faulty system are transformed such that its behavior is similar to that of the nominal system from the viewpoint of the controller. It transforms the controller output for the faulty system preserving the stability and performance. Input-to-state stabilizing LPV gains of the virtual actuator and sensor are obtained by solving LMIs. The gains guarantees the input-to-state stability (ISS) of the closed-loop reconfigured system. Moreover, we obtain performances in terms of the ISS gains for the virtual actuator, the virtual sensor, and their interconnection. Minimizing these performances is formulated as convex optimization problems subject to LMI constraints. The effectiveness of the method is demonstrated via a numerical example and stator current control of an induction motor.