Robust fault detection in descriptor linear systems via generalized unknown input observers

A new parametric approach for robust fault detection in descriptor linear multivariable systems with unknown disturbances is proposed. The residual is generated using a full-order generalized state observer. Based on a recently proposed parametric eigenstructure assignment approach, parameterizations of the observer gain and the eigenvectors of the observer system are presented. By combining the parameterizations of the observer eigenvectors and an established condition for disturbance decoupling in descriptor linear systems, the effect of the disturbance to the residual signal is decoupled. A simple algorithm is presented. An example shows the effect of the proposed approach.