Simultaneous Estimation of States and Sensor Faults Based on a Multiobserver Structure for Nonlinear Systems

The present paper proposes a multi-observer structure for nonlinear systems in the presence of sensor faults. These faults are considered as auxiliary state variables; thus, a descriptor system is constructed based on a decoupled multimodel. Thanks to this descriptor structure, the proposed multiobserver provides more degrees of freedom in the design procedure and simultaneous robust estimation of the states and the sensor faults without any assumption concerning the fault dynamics. The Lyapunov approach is exploited to establish the stability conditions that are expressed via Linear Matrix Inequalities (LMIs). The superiority of the proposed strategy is illustrated through simulation results and a comparative study.