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Showing papers by "Ron J. Patton published in 1992"


Journal ArticleDOI
TL;DR: The paper presents a complete description of a robust fault detection approach based on eigenstructure assignment, both in continuous and discrete-time domains, and shows that the scheme can detect soft or incipient faults efficiently.
Abstract: This paper examines a robust fault detection scheme that can be used to detect faulty sensors of jet engines. The fault detection scheme has to be insensitive to disturbances while being highly sensitive to sensor faults (robust). The paper presents a complete description of a robust fault detection approach based on eigenstructure assignment, both in continuousand discrete-time domains. By assigning the left (or right) eigenvectors of the observer orthogonal (or parallel) to the disturbance directions, the robust (disturbance decoupling) fault detection is achieved. The approach has been applied to a realistic jet engine simulation system. The system is a 17th-order system, and a reduced-order model is used to approximate the system. Modeling errors are considered as disturbances acting on the fault detection scheme. A particularly novel feature of the work is the development and use of a new method (new in this context) for estimating disturbance direction. The robust fault detection scheme design uses this estimated direction as that of the direction of unknown inputs (disturbances). Simulation results show that the scheme can detect soft or incipient faults efficiently.

192 citations


Book ChapterDOI
01 Jan 1992
TL;DR: In this article, a review of the state of the art in fault detection and isolation for dynamic systems based on the parity space concept is provided and tutorial examples are given to illustrate the theory.
Abstract: This paper reviews the state of the art in fault detection and isolation for dynamic systems, based on the parity space concept. Some important definitions are provided and tutorial examples are given to illustrate the theory. The main aim has been to draw together the important links between parity space approaches; in particular the important links between open-loop and closed-loop strategies. The parity space is used as a new re-statement to unify residual generation methods. The robustness and isolation problems in fault diagnosis is mainly addressed in the paper. Moreover, an important definition for robustness is made and the recent works on robust fault diagnosis methods are described. Some new design methods are given to illustrate the potential of robust residual generation using closed-loop parity space ideas.

85 citations


Proceedings ArticleDOI
16 Dec 1992
TL;DR: In this paper, the authors focus on the derivation of suitable mathematical models of a jet engine, to enable robust fault diagnosis designs to be achieved, which can be described as an additional term in the dynamic structure.
Abstract: Modeling uncertainty is an inevitable consequence of the complexity of jet engine systems, and accurate dynamic models can never be fully obtained. The authors concentrate on the derivation of suitable mathematical models of a jet engine, to enable robust fault diagnosis designs to be achieved. The modeling uncertainty can be described as an additional term in the dynamic structure. Based on this structure, a robust fault diagnosis scheme can be designed. New methods are presented for determining the structure of modeling uncertainty. The work uses a 17th order nonlinear jet engine simulation model to illustrate the methods proposed. The simulation results show the power of the method in modeling jet engine systems for robust fault diagnosis purposes. >

52 citations


Ron J. Patton1, Jie Chen1
26 Feb 1992
TL;DR: In this article, the state observer with disturbance de-coupling design is recommended as a good solution for robustness in fault diagnosis and further research topics in robust fault diagnosis are outlined.
Abstract: Quantitative model-based fault diagnosis has become a popular issue in safety-critical systems, e.g., aircraft, spacecraft, chemical processes and nuclear plants. The use of dynamical system model information has been widely recognized as an important approach to fault detection and isolation for the case when there are no repeated hardware units. A prerequisite for feasibility of quantitative model-based fault diagnosis is satisfactory robust performance with respect to uncertainties. The paper discusses the different problems in robustness and surveys the state of the art in robust solutions for quantitative model-based fault diagnosis. The state observer with disturbance de-coupling design is recommended as a good solution for robustness in fault diagnosis. Further research topics in robust fault diagnosis are outlined.

42 citations


Proceedings ArticleDOI
16 Dec 1992
TL;DR: In this article, the authors present new methods for determining the structure of modeling uncertainties based on deconvolution of unknown inputs, and several theoretical conditions are discussed, and a jet engine system is used to illustrate the method.
Abstract: Modeling uncertainty can be described as an additional term in the dynamic equation of a system that has a certain structure. Based on this structure, a robust fault diagnosis scheme can be designed. The authors present new methods for determining the structure of modeling uncertainties based on deconvolution of unknown inputs. Several theoretical conditions are discussed, and a jet engine system is used to illustrate the method. Simulation results show the power of this method for modeling uncertainties for the purpose of robust fault diagnosis. >

29 citations


Book ChapterDOI
01 Jan 1992
TL;DR: In this paper, a method of computing the unknown input distribution matrix is proposed as a powerful alternative method to either reidentification of plant parameters arising from different operating points or to the use of non-linear residual generation.
Abstract: Uncertainties in dynamic systems are an inevitable consequence of non-linearity and complexity, and they obscure the performance of fault diagnosis (detection, isolation and identification). In order to achieve robust and reliable fault diagnosis, the unknown input (disturbance) de-coupling principle has been employed in recent research. In this paper, a method of computing the unknown input distribution matrix is proposed as a powerful alternative method to either re-identification of plant parameters arising from different operating points or to the use of non-linear residual generation. The determination of a suitable unknown input distribution matrix to achieve disturbance de-coupling is described as an optimization problem which is solved here via a Singular Value Decomposition approach. An example of robust fault detection applied to a jet engine system is included as an illustration.

23 citations



Journal ArticleDOI
TL;DR: In this paper, a robust fault detection approach based on eigenstructure assignment technique is proposed for an 11th order model of a nuclear reactor system, which is designed to be insensitive to disturbances, whilst being highly sensitive to faults.

2 citations


Proceedings ArticleDOI
13 Sep 1992
TL;DR: An optimized eigenstructure assignment method is developed to provide for the trade-off between the minimization of control effort and the assignment of a prescribed modal structure in a multirate feedback structure.
Abstract: The design of feedback controllers for multirate digital systems is considered. The two main problems associated with such a scheme are the adverse effects of intersample cross-coupling and the large, switched control signals that normally result from a multirate feedback structure. The two problems present conflicting design objectives. Thus, a solution must seek to achieve an acceptable compromise between the minimization of control effort and the assignment of a prescribed modal structure. An optimized eigenstructure assignment method is developed to provide for this trade-off. The achievement of each design objective is governed by weighting factors in the optimization cost function. The design of a stability augmentation system for the lateral motion of an aircraft illustrates the application of this method. >