Component failure estimation with Unknown Input Observer: A physical approach

In the literature Unknown Input Observers for sensor and actuator failure estimation are widely developed. None of them concerns component fault estimation. These analytical approaches are based on state equation description and complex numerical calculation. The present paper deals with physical component failure estimation based on bond graph approach as power full methodology for dynamic modeling of multi-physical systems. The additional energy due to the component failure (clearly displayed in the model) is considered as unknown input. Furthermore, properties of this observer are based on the finite and infinite structures and are synthesized directly from the graphical model, which can be pointed out from physical, structural and causal properties of used graphical representation. The developed methodology is validated in real experimental hydraulic process allowing valve and tank leakage failure estimation.