Residual function design for linear multivariable systems

Classical model–based fault detection schemes for linear multivariable systems require the definition of suitable residual functions. This paper shows the possibility of identifying residual generators even when the system model is unknown, by following a black–boxapproac h. The result is obtained by using canonical input–output polynomial forms which lead to characterise in a straightforward fashion the basis of the subspace described by all possible residual generators. The performance of the proposed identification method is tested by means of a Monte Carlo simulation.