Design of the Robust Unknown Input Fault Isolation Observer for Automotive Engines

Enhancement of unknown input fault detection observer (UIFDO) to obtain unknown input fault isolation observer (UIFIO) is presented in this paper by eigenstructure assignment approach. Not only the unknown inputs are concerned but also the effects due to unstructured uncertainties is adopted and suppressed with well-conditioned eigenstructure assignment. Experimental results of a Nissan commercial engine is illustrated to prove the validity of theoretical derivation.