H_-/L_∞ fault detection observer design for linear parameter-varying systems

We propose an H_-/L_∞ fault detection observer for linear parameter varying systems with unknown disturbance and actuator fault. The fault detection observer is designed to enhance the fault sensitivity of residual and attenuate the effect of disturbance on residual such that timely and robust fault detection is achieved. The observer design method is carried out in the finite frequency domain and the design conditions are expressed as a set of linear matrix inequalities. By using L_∞ performance index to measure the effect of disturbance on residual, the fault detection observer exhibits a peak-to-peak disturbance attenuation performance, which can provide a dynamic threshold for residual evaluation in fault detection. Numerical simulations are conducted to verify the effectiveness of the proposed method.