Adaptive Fuzzy Observer Design for a Class of Switched Nonlinear Systems With Actuator and Sensor Faults

In this paper, an adaptive fault estimation approach is proposed for a class of switched nonlinear systems. The considered system is assumed to possess unknown nonlinearities, unmeasured states, and simultaneous sensor and actuator faults. Fuzzy logic systems are applied to approximate the unknown nonlinear terms. Two new adaptive fuzzy observers are designed where the sensor and actuator faults can be estimated separately. On the basis of average dwell time approach and Lyapunov stability theory, the resulting error system is proven to be bounded stable with designed parameters. Finally, a simulation example is presented to illustrate the effectiveness of the designed observers.