A switched LPV observer for actuator fault estimation

In this paper, an actuator fault estimation problem is tackled, based on the LPV approach. First, the actuator fault is modeled in the form of a multiplicative fault by using a constant coefficient representing the loss of efficiency of the actuator’s power α. Therefore, the estimation of a time varying faulty actuator can be transformed into the estimation of a constant coefficient α. Then, the faulty system is rewritten in the form of a switched LPV system. The coefficient α and the system states are estimated using an extended switched observer. The stability and performance of the observer is ensured considering a switched time-dependent Lyapunov function. The observer gains are derived based on LMI solutions for polytopic switched systems. Some simulation results are presented that show the effectiveness of this approach.