Fault-tolerant control of uncertain nonlinear systems with nonlinearly parameterized fuzzy systems

The design of fault tolerant control (FTC) for a class of uncertain nonlinear systems is studied in this paper. The considered system cannot be feedback linearized, and the nonlinear system functions are all unknown. Besides, some unknown actuator faults and external disturbances enter into the system during operation. A novel fault tolerant controller is proposed by incorporating adaptive fuzzy approximation, backstepping design and robust control into FTC technique. The fuzzy systems which are used to be approximators are nonlinearly parameterized because the fuzzy membership functions are uncertain to designer. Both approximation errors and external disturbances are attenuated by additional control. The designed controller guarantees the closed loop system stable and the output tracking to the reference signal. A simulation example is given to show the effectiveness of the proposed control approach.