Observer-based Fault Detection Systems Research Articles

An integrated trade-off design of observer based fault detection systems

In this paper, problems related to the integrated design of observer based fault detection systems are addressed. In the context of norm based residual evaluation, a trade-off between false alarm rate (FAR) and fault detection rate (FDR) is first formulated. Aiming at minimizing FAR under given FDR, an approach is then presented for the design of observer based fault detection systems. For this purpose, the well-established factorization technique is applied. Finally, study is devoted to the comparison between the existing methods and the proposed one.

Networked Fault Detection Systems with Noisy Data Transmission (Vernetzte Fehlerdetektionssysteme mit verrauschter Datenübertragung)

In this paper, a networked observer-based fault detection (FD) system is presented. First, the influence of noisy data transmission on the FD performance is analyzed and modeled. Based on it, a design scheme is developed for the construction of observer and residual evaluation unit. The core of this scheme is the integrated design of the coding strategy and FD system. The resulting FD system ensures high fault detectability and low false alarm rate.

A model-free approach to fault detection of continuous-time systems based on time domain data

In this paper, a model-free approach is presented to design an observer-based fault detection system of linear continuous-time systems based on input and output data in the time domain. The core of the approach is to directly identify parameters of the observer-based residual generator based on a numerically reliable data equation obtained by filtering and sampling the input and output signals.

A MODEL-FREE FAULT DETECTION APPROACH OF CONTINUOUS-TIME SYSTEMS FROM TIME DOMAIN DATA

In this paper, a model-free approach is presented to design an observer-based fault detection system of linear continuous-time systems based on input and output data in the time domain. The core of the approach is to directly identify parameters of the observer-based residual generator based on a numerically reliable data equation obtained by filtering and sampling the input and output signals.

Design of parametric fault detection systems: An H-infinity optimization approach

Problems related to the design of observer-based parametric fault detection (PFD) systems are studied. The core of our study is to first describe the faults occurring in system actuators, sensors and components in the form of additive parameter deviations,then to transform the PFD problems into a similar additive fault setup, based on which an optimal observer-based optimization fault detection approach is proposed. A constructive solution optimal in the sense of minimizing a certain performance index is developed. The main results consist of defining parametric fault detectability, formulating a PFD optimization problem and its solution. A numerical example to demonstrate the effectiveness of the proposed approach is provided.

APPLICATION OF ROBUST OBSERVER-BASED FDI SYSTEMS TO FAULT TOLERANT CONTROL

In this paper, an active fault tolerant control (FTC) strategy is presented for linear dynamic systems. The robust observer-based fault detection and isolation (FDI) systems are applied to guide the reconfiguration of controller parameters to achieve the optimal control performance during different operating conditions of the system: fault-free, fault detected and fault isolated. The selection of design parameters is achieved using the linear matrix inequality (LMI) optimization technique.

A unified approach to the optimization of fault detection systems

In this paper, problems of optimizing observer-based fault detection (FD) systems in the sense of increasing the robustness to the unknown inputs and simultaneously enhancing the sensitivity to the faults are studied. The core of the study is the development of an approach that simultaneously solves four optimization problems. Different algorithms are derived for the application of this approach to the optimal selection of post-filters as well as optimization of fault detection filters, and to the systems with and without structure constraints. The achieved results also reveal some interesting relationships among the optimization problems considered. Copyright © 2000 John Wiley & Sons, Ltd.

An approach to time domain optimization of observer-based fault detection systems

This contribution deals with the problems related to robust fault detection. An approach to time domain optimization of observer-based fault detection systems is proposed. The core of this approach is the integration of robust residual generation and evaluation which provides a time domain optimal solution for the robustness problem of fault detection. The discussion on the optimal solution reveals some potential possibilities and ideas for improving the performance of fault detection systems.

Survey of robust residual generation and evaluation methods in observer-based fault detection systems

The paper outlines recent advances of the theory of observer-based fault diagnosis in dynamic systems towards the design of robust techniques of residual generation and residual evaluation. Emphasis will be placed upon the latest contributions using frequency domain techniques including H∞ theory, nonlinear unknown input observer theory, adaptive observer theory, artificial intelligence including fuzzy logic, knowledge-based techniques and the natural intelligence of the human operator. Two representative examples illustrate the efficiency of the observer-based approach.

Reliable Decision Unit Utilizing Fuzzy Logic for Observer Based Fault Detection Systems

Reliability of the diagnostic part of the fault detection system which is in charge of isolation of a fault, is as important as the robustness of the residual generator because the isolation logic unit provides the information about the kind of fault, failed components and the severity of the fault. This paper deals with the rule base design problem for the observer based fault detection systems and main emphasis is placed on the method of rule modification using the excess redundancy that is inherent in the observer based FDS and employing fuzzy logic inference. It is shown that the combined use of compensatory operator and non-compensatory one provides an useful means of enhancing the reliability of the diagnostic decision process even in the cases that some residuals are perturbed by external disturbances and some other type of uncertainties.

Optimization of Observer-Based Fault Detection Systems

Problems related to observer-based fault detection of uncertain dynamic systems are studied. The core of this study is the optimization of fault detection systems aiming at simultaneously increasing the robustness against uncertainties and the sensitivity to faults. The basic idea is integrating together the residual generation and residual evaluation. Two approaches to robust fault detection with emphasis on an integration of residual generation and evaluation are proposed.