Observer-Based Adaptive Decentralized Fault-Tolerant Control of Nonlinear Large-Scale Systems With Sensor and Actuator Faults

This paper investigates the problem of decentralized fault-tolerant tracking control for nonlinear large-scale systems with sensor and actuator faults. Due to the adverse coupling effects that unknown sensor faults and output interconnections coexist, the previous methods fail to achieve decentralized tracking controls. Focus of this paper is particularly on addressing this issue. First, a decentralized fault-tolerant observer is constructed to simultaneously estimate unmeasured state and compensate the actuator faults. Then, an adaptive signal compensation mechanism is presented to mitigate the effects of sensor faults and output interconnections. By applying the cubic absolute-value Lyapunov function analysis method, it is shown that all the signals are bounded and the tracking error of each subsystem converges to an adjustable neighborhood of zero. An example of a large-scale power system is adopted to illustrate the effectiveness of the obtained scheme.