H^∞ fault detection filter design for linear discrete-time systems with multiple time delays

Abstract

This paper deals with the design of H^∞ fault detection filters for discrete-time systems with multiple time delays, in which total decoupling of the fault effects from unknown inputs, including model uncertainties and external plant disturbances, is impossible. Through the appropriate choice of the filter gain, the filter is convergent if there is no fault in the system, and the effect of disturbances on the residual is minimized in the sense of H^∞ norm. The problem of achieving satisfactory sensitivity of the residual to faults is formulated and its solution given. The detection threshold associated with the filter is also discussed. Finally, a wind tunnel example illustrates the efficiency of the proposed method.