Fault-tolerant control of uncertain MIMO nonlinear systems: An adaptive fuzzy approach

This paper studies the problem of fault-tolerant control of uncertain multiple-input multiple-output (MIMO) nonlinear systems, and presents a fault-tolerant control scheme to deal with both lock-in-place and loss of effectiveness faults of actuators. A class of MIMO nonlinear systems with the block-triangular structure and unknown nonlinearities is considered. By combining the adaptive fuzzy approach with the backstepping technique, the controllers and the adaptive laws for the fault-tolerant scheme are derived. Though there are unknown and time-varying faults in the actuators, the derived controllers can guarantee the stability and desired output tracking of the closed-loop system without the help of fault detection and diagnosis. A simulation example is given to show the effectiveness of the control scheme.