Fault Reconstruction for Continuous-Time Switched Nonlinear Systems Via Adaptive Fuzzy Observer Design

This paper investigates the fault reconstruction problem for a class of continuous-time switched systems subject to persistent dwell-time (PDT) switching. In order to relax the rank condition of the perturbations' coefficient matrices in fuzzy fault reconstruction results, a novel adaptive fuzzy design approach is developed by decomposing the perturbations into virtual faults and states. Then, the PDT switching is first considered in the adaptive fuzzy observer to overcome the restricted switching frequency problem, which can guarantee the stability of the estimation error systems with fast and slow switching characteristics simultaneously. Moreover, the unknown nonlinearities, actuator faults and disturbances can be reconstructed by the designed adaptive mechanism, where the switching problem of sliding surfaces in sliding mode observers can be avoided. Finally, a circuit system example is provided to demonstrate the effectiveness of the fault reconstruction scheme.