Adaptive fault tolerant control for actuator bias of nonlinear systems

Abstract

This paper deals with active fault tolerant controller design against time-varying actuator fault, aiming to improve the robustness, sensitivity of fault detection and the rapidity of whole diagnosis and compensation procedure. A high-gain observer technique is developed to design a residual signal with the estimation error of system states and the derivatives of system output. Then a reconfiguration controller is directly constructed based on the fault information from diagnosis procedure. A qualitative relation is derived to connect the robustness, rapidity and sensitivity of the proposed fault diagnosis scheme with the observe parameters. By prescribing the observer/controller parameters, the set of detectable faults, the time of detection and compensation and the bound of the closed-system signals are quantified. Finally, the theoretical results are illustrated by a simulation example of surfacemounted permanent magnet synchronous motors (PMSM).

Adaptive fuzzy logic system–based fault tolerant control for a class of discrete-time switched nonlinear systems

“…Remark 5. Compared with the existing results, the following aspects should be emphasized: Unlike the methods in previous works 4,7 and Kang et al, 10 in which the adaptive FTC problem for nonswitched systems were considered, this article concentrates on the case for switched system. Due to the complicity of the switched systems, it brings a great obstacle in the design of controller.…”

“…[1][2][3][4][5][6][7] Two classes of actuator faults are always considered: the actuator loss of effectiveness (LOE) 8,9 and the actuator bias fault. 10 When the parameters of the actuator fault are known, it is much easy to design the fault tolerant controller, and if the parameters of the actuator fault are unknown, it will bring great obstacle for the fault tolerant controller design. In Benosman and Lum, 11 the actuator LOE fault was considered, and a passive fault tolerant controller was proposed.…”