Observer‐based active fault‐tolerant control for a class of pure‐feedback switched nonlinear systems

Abstract

An active fault-tolerant control (FTC) strategy for a class of switched nonlinear systems in pure-feedback form by using average dwell time method is investigated in this article. The unknown functions in the system are approximated directly by fuzzy logic systems. A fuzzy state observer is designed to estimate the unavailable states, based on which, a fault detection project is designed. In fault-free case, all the signals in the closed-loop system are proved to be bounded under the control of the designed input. The fault estimation and FTC projects will be activated after a fault has been detected. In addition, the active FTC is constructed in the framework of backstepping design technique. The proposed controller guarantee that all the closed-loop signals remain bounded under a class of switching signals with average dwell time. The simulation results show the effectiveness of the proposed method.

Observer-Based Control for High-Order Fully Actuated Systems

“…Compared to results of the state observer design for nonlinear systems, results of observer-based control are much fewer, and they are often more demanding in terms of system structure and assumptions. For example, some references require the system to be single-input ( [13], [14]) or to have some kind of "triangular structure", typically a strict feedback structure ( [13]- [17]), a semi-strict feedback structure ( [18]), a pure feedback structure ( [19]- [21]), a special nonstrict-feedback structure ( [22]- [24], [26], [27]), a feedforward structure ( [28]- [30]), and some other triangular structures ( [31], [32]), etc. There are also lots of representative references that require systems to have some "linear dominant" structure (see e.g.…”

Intermediate variable‐based adaptive fault estimation for a class of Lipschitz nonlinear systems

“…In the field of fault diagnosis (FD), the fault detection and isolation (FDI) technology is key to increasing system safety and reliability standards (see other relevant works 1‐4 ). It is vital to point out that in practice, with the augment of equipment operating time and the occurrence of various unknown situations, all kinds of system failures may inevitably happen, such as time delay, model uncertainty, interference and noise (such as References 5‐10). It is tough to precisely grasp the sizes and shapes of faults only through the FDI scheme.…”

“…It is tough to precisely grasp the sizes and shapes of faults only through the FDI scheme. Fortunately, the fault estimation can characterize the details of fault information online and automatically execute the required fault detection 8,11,12 . Under this trend, the observer‐based fault estimation methods have aroused extensive attention of many scholars (such as References 13‐18).…”

“…Fortunately, the fault estimation can characterize the details of fault information online and automatically execute the required fault detection. 8,11,12 Under this trend, the observer-based fault estimation methods have aroused extensive attention of many scholars (such as . Consequently, the improvement and optimization of observers have become a research hotspot in the area of fault estimation.…”

Dynamic observer‐based fault estimation and fault‐tolerant control for switched stochastic systems with multiple faults

“…In [30,31], FE and FTC problems were studied for nonlinear switched systems. In [32,33], a new FD scheme was proposed; based on fault detection, the FE and FTC scheme will be started immediately after the fault is detected. For switched nonlinear systems with various kinds of faults, the fuzzy modeling techniques have been applied, and the FE and FTC issues have been carried out.…”