Sensor Fault Detection for a class of Uncertain Nonlinear Systems Using ‎Sliding Mode Observers

This paper deals with the issues of sensor fault detection for a class of Lipschitz uncertain nonlinear system. By definition coordinate transformation matrix for system states and output system, at first the original system divided into two subsystems. the first subsystem includes uncertainties but without any sensor faults and the second subsystem has sensor faults but is free of uncertainties. Then sensor faults in second subsystem are formed as actuator faults. For the aim of fault detection (FD) two sliding mode observer is designed for two subsystems. The necessary matrices and parameters to design observers are obtained by solving linear matrix inequality (LMI) problem.  Stability condition of observer’s dynamics are reviewed based on Lyapunov approach. Finally simulation example is given to illustrate the effectiveness proposed approach.