Sensor fault tolerant controller for nonlinear systems using an uncoupled state multiobserver

In this paper an active sensor fault tolerant control for a nonlinear system modeled by an uncoupled multimodel is developed. For the considered uncoupled multimodel a switching control strategy is elaborated. This strategy needs basically the sensor fault estimation. According to an augmented uncoupled state multimodel, an unknown input multiobserver is synthesized to accomplish the fault estimation task. The fault tolerant control aim consists on maintaining performances nearby the nominal ones even in the presence of sensor fault. Once the sensor fault is accurately estimated the nominal control is actively modified and an additional control law is calculated to tolerate its effects. An illustrative example is given to test the efficiency of the proposed strategy.