Design of a robust fault detection based observer for linear switched systems with external disturbances

This paper concerns the design of a robust hybrid observer for switched linear systems with unknown inputs and modeling error. It extends some previous results to a more general class of switched-state jump linear hybrid systems. The observer herein proposed is synthesized for the task of robust fault detection without the knowledge of the active mode. Moreover, the robust fault detection problem has been considered as a standard H∞H∞ model matching. Then, a suitable trade-off between the robustness of the unknown inputs and the sensitivity to faults has been obtained thanks to a H∞H∞ performance index. The latter is finally optimized using an iterative LMI solution procedure.