Sliding mode estimation schemes for unstable systems subject to incipient sensor faults

This paper proposes a new method for the analysis and design of sliding mode observers for fault reconstruction which is applicable for unstable systems. The proposed design addresses one of the restrictions in the existing literature (in which the open-loop system needs to be stable). Simulation results from an open-loop unstable system representing a fighter jet model show good fault estimation, even when simulated on the full nonlinear model.