Adaptive fault compensation for global performance tracking control of sensor faulty MIMO nonlinear systems with unmeasured states

Abstract

In this article, the problem of global prescribed performance tracking control for multi-input multi-output (MIMO) nonlinear systems with sensor faults and unmeasured states is investigated. By constructing a state observer that incorporates an adaptive sensor fault compensation mechanism, the impact of the loss of sensor effectiveness is alleviated through the cubic absolute-value Lyapunov function analysis method. Based on several transformation functions and a time-varying scaling function, the tracking errors are restricted within the global prescribed performance without the constrained initial conditions. Considering the abrupt change in tracking errors due to the existence of sensor faults, a monitoring function to supervise the excessive loss of sensor effectiveness is designed. Furthermore, a novel reconfigurable controller can be constructed with the detected fault time instant and the global prescribed performance. The analysis demonstrates that all signals remain bounded and the tracking errors are maintained within the designed global prescribed performance regardless of sensor faults. Finally, the efficacy of the presented control scheme is demonstrated by the simulation results.