• Journal of Institute of Control, Robotics and Systems
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• v.4 no.6
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• pp.695-702
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• 1998

In this paper, we propose a novel fault isolation filter design method using the left eigenstructure assignment scheme proposed by Choi et. al., The proposed filter shows good fault isolation performance with exact eigenstructure assignment. An eigenstructure assignment methodology which satisfies the required fault isolation conditions is also proposed. The proposed method guarantees that the corrupted m simultaneous faults can be isolated when the number of available output measurements are (m+1).

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.5
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• pp.384-392
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• 2001

In this paper, we propose a novel robust fault isolation filter design method using the left eigenstructure assignment scheme proposed by the authors. The proposed method guarantees that the ${\gamma}$ simultaneous faults can be isolated when the number of available outpur measurements is ${\gamma}$. Moreover, if there exist redundant output measurements, the eigenvaluses of te filter system can be assigned to the desired position or the filter can be designed robustly to, the system parameter variation. Liu & Si developed a filter design method which has the same purpose, fault isolation. However their method cannot use the redundant freedom of the output matrix C. The proposed filter can use the redundant freedom of the matrix C effectively. Beside this in this paper, an eigenstructure assignment methodology that satisfies the required fault isolation conditions is also proposed. The proposed fault isolation filter was applied for isolating the simultaneous faults to a VTOL aircraft in order to verify the fault isolation performance.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.85-85
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• 2000

In this paper, we propose a novel robust fault isolation filter design method using the left eigenstructure assignment scheme proposed b\ulcorner author. An eigenstructure assignment methodology that satisfies the required fault isolation conditions is also proposed. The proposed method guarantees that the corrupted ${\gamma}$ simultaneous faults can be isolated when the numbers of available output measurements are ${\gamma}$.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1117-1124
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• 2011

An integrated fault detection and isolation method is proposed in this paper. The main objective of this paper is development fault detection, isolation and diagnosis algorithm based on the DKF (Decentralized Kalman Filter) and the bank of IMM (Interacting Multiple Model) filters using penalty scalar for both partial and total faults and the outlier detection algorithm for preventing false alarm also included. The proposed FDI (Fault Detection and Isolation) scheme is developed in four phases. In the first phase, the outlier detection filter is designed to prevent false alarm as a pre-filter. In the second phases, two local filters and master filter are designed to detect sensor faults. In the third phases, the proposed FDI scheme checks sensor residual to isolate sensor faults and 11 EKFs actuator fault models are designed to detect wherever actuator faults occur. In the last phases, four filters are designed to identify the fault type which is either the total fault or partial fault. The developed scheme can deal with not only sensor and actuator faults, but also preventing false alarm. An important feature of the proposed FDI scheme can decreases fault isolation time and figure out not only fault detection and isolation but also fault type identification. To verify the proposed FDI algorithm performance, the Simulator is also developed under the Matlab/Simulink environment.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.583-589
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• 2000

This paper presents a novel fault isolation filter design method using left eigenstructure assignment scheme proposed by the first author et al. The proposed method shows good performance of fault isolation with an exact eigenstructure assignment and guarantees that the corrupted ${\gamma}$ faults can be isolated simultaneously when the number of available output measurements are equal to or larger than (${\gamma}+1$). A numerical example for the fault isolation filter is also included.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1225-1231
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• 2009

One reaction wheel cluster of satellite usually has four reaction wheels. Each wheel is not arranged parallel to the attitude axis of satellite. Therefore, if one reaction wheel is broken, it is very hard to isolate the fault except using the sensors of wheel itself. In this paper, the isolator of satellite reaction wheel cluster is designed. Using a dual filter, FDP(Fault Detection Parameter) is made to detect fault, and using a multi-hypothesis extended Kalman filter, fault isolation of wheel cluster is done. We verify the improvement of isolation performance of wheel cluster by simulation with 4-reaction wheel cluster.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.1
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• pp.73-83
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• 2006

In this paper, a redundancy management system for aircraft is studied, and fault detection and isolation algorithms of inertial sensor system are proposed. Contrary to the conventional aircraft systems, UAV system cannot allow triple or quadruple hardware redundancy due to the limitations on space and weight. In the UAV system with dual sensors, it is very difficult to identify the faulty sensor. Also, conventional fault detection and isolation (FDI) method cannot isolate multiple faults in a triple redundancy system. In this paper, two FDI techniques are proposed. First, hardware based FDI technique is proposed, which combines a parity equation approach with a wavelet based technique. Second, analytic FDI technique based on the Kalman filter is proposed, which is a model-based FDI method utilizing the threshold value and the confirmation time. To provide the reference value for detecting the fault, residuals are calculated using the extended Kalman filter. To verify the effectiveness of the proposed FDI methods, numerical simulations are performed.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1401-1410
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• 2014

This paper presents a modified adaptive fading EKF (AFEKF) for sensor fault detection and isolation in the satellite. Also, the fault detection and isolation (FDI) scheme is developed in three phases. In the first phase, the AFEKF is modified to increase sensor fault detection performance. The sensor fault detection and sensor selection method are proposed. In the second phase, the IMM filer with scalar penalty is designed to detect wherever actuator faults occur. In the third phase of the FDI scheme, the sub-IMM filter is designed to identify the fault type which is either the total or partial fault. An important feature of the proposed FDI scheme can decrease the number of filters for detecting sensor fault. Also, the proposed scheme can classify fault detection and isolation as well as fault type identification.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.6
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• pp.430-436
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• 1987

A Detection filter that can be used for the Detection and Isolation of process faults is proposed by the use of fault vector modelling, and is applied to DC Motor fault detection. The proposed detection filter is a new one in a view point that its outputs are the estimates of fault variables(or linear combination of them) while all the existing filters estimate the state of process. By this properties, the process fault detection systems with this filter can be constructed in very simple structure. Besides the simplicity of structure and design procedure, the filter has an useful feature that various types of fault can be estimated via the filter by choosing appropriate fault models.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.797-806
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• 2012

Fault detection and isolation (FDI) algorithms provide fault monitoring methods in GPS measurement to isolate abnormal signals from the GPS satellites or the acquired signal in receiver. In order to monitor the occurred faults, FDI generates test statistics and decides the case that is beyond a designed threshold as a fault. For such problem of fault detection and isolation, this paper presents and evaluates position domain integrity monitoring methods by formulating various pseudorange prediction methods and investigating the resulting test statistics. In particular, precise measurements like carrier phase and Doppler rate are employed under the assumption of fault free carrier signal. The presented position domain algorithm contains the following process; first a common pseudorange prediction formula is defined with the proposed variations in pseudorange differential update. Next, a threshold computation is proposed with the test statistics distribution considering the elevation angle. Then, by examining the test statistics, fault detection and isolation is done for each satellite channel. To verify the performance, simulations using the presented fault detection methods are done for an ideal and real fault case, respectively.