• Title, Summary, Keyword: Fault detection and isolation

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Two-Faults Detection and Isolation Using Extended Parity Space Approach

  • Lee, Won-Hee;Kim, Kwang-Hoon;Park, Chan-Gook;Lee, Jang-Gyu
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.411-419
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    • 2012
  • This paper proposes a new FDI(Fault Detection and Isolation) method, which is called EPSA(Extended Parity Space Approach). This method is particularly suitable for fault detection and isolation of the system with one faulty sensor or two faulty sensors. In the system with two faulty sensors, the fault detection and isolation probability may be decreased when two faults are occurred between the sensors related to the large fault direction angle. Nonetheless, the previously suggested FDI methods to treat the two-faults problem do not consider the effect of the large fault direction angle. In order to solve this problem, this paper analyzes the effect of the large fault direction angle and proposes how to increase the fault detection and isolation probability. For the increase the detection probability, this paper additionally considers the fault type that is not detected because of the cancellation of the fault biases by the large fault direction angle. Also for the increase the isolation probability, this paper suggests the additional isolation procedure in case of two-faults. EPSA helps that the user can know the exact fault situation. The proposed FDI method is verified through Monte Carlo simulation.

Satellite Fault Detection and Isolation Scheme with Modified Adaptive Fading EKF

  • Lim, Jun Kyu;Park, Chan Gook
    • 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.

Frequency analysis based fault detection and isolation of induction motors (주파수 해석을 이용한 유도전동기의 고장 검출 및 분류)

  • 신필재;이인수;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • pp.702-705
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    • 1996
  • Recently, induction motors are used more widely because of their low cost and simple structure. Therefore, the importance of fault detection and isolation of induction motors significantly increases. In most case the line current is used for fault detection and isolation. But in case that an induction motor has an inverter for control, it distorts the information of faulty state included in the line current. This paper proposes a new method for fault detection and isolation of induction motors that is speed controlled by the inverter using frequency analysis of the reference current instead of the line current for fault detection and isolation.

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Hybrid fault detection and isolation for uncertainty system (불확실성을 고려한 시스템에서의 복합형 이상검출 및 격리)

  • 유호준;김대우;권오규
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1432-1435
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    • 1997
  • This paper proposes a fault detection and isolation metho by combining the parameter estimation method[4] with the observer method[2] to use merits of both methods. To verify the performance of the method proposed some simulations applied to remotely piloted vehicle are performed.

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An Integrated Fault Detection and Isolation Method for Sensors and Actuators of LEO Satellite (저궤도 인공위성의 센서 및 구동기 통합 고장검출 및 분리 기법)

  • Lim, Jun-Kyu;Lee, Jun-Han;Park, Chan-Gook
    • 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.

Fault Detection and Isolation using navigation performance-based Threshold for Redundant Inertial Sensors

  • Yang, Cheol-Kwan;Shim, Duk-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • pp.2576-2581
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    • 2003
  • We consider fault detection and isolation (FDI) problem for inertial navigation systems (INS) which use redundant inertial sensors and propose an FDI method using average of multiple parity vectors which reduce false alarm and wrong isolation, and improve correct isolation. We suggest optimal isolation threshold based on navigation performance, and suggest optimal sample number to obtain short detection time and to enhance detectability of faults little larger than threshold.

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Fault Detection And Isolation Of Two DC-DC Converters Parallel Operation By ZCT Method (ZCT방식을 이용한 두 개의 컨버터 병렬 운전 시고장 검출 및 분리)

  • 박상은
    • Proceedings of the KIPE Conference
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    • pp.172-176
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    • 2000
  • The paper presents the fault detection and isolation of two DC-DC converters parallel operation by ZCT method. Two experimental prototype converters were designed and implemented for evaluation of fault tolerant system. The experimental results show that fault detection and isolation circuit works very well.

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A Study on Actuator Fault Detection and Isolation in Airplanes using Fuzzy Logic (퍼지로직을 이용한 항공기 고장 검출 및 분리)

  • Lee Jang-Ho;Kim You-Dan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.3
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    • pp.140-148
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    • 2004
  • Fault detection and isolation(FDI) and reconfigurable flight control system provide better survivability even though actuator faults occur. In this study, a new fault detection and isolation algorithm is proposed using fuzzy logic. When the FDI system detects the actuator fault, the fuzzy logic investigates the state variables to find which actuator has fault. Proposed fuzzy detection algorithm detect not only a single fault but also multiple faults. After detecting the fault, the reconfigurable flight control system begins operating for compensating the effects of the fault. A numerical simulation using six degree-of-freedom nonlinear aircraft model is performed to verity the performance of the proposed fault detection and isolation scheme.

Performance Comparison of GPS Fault Detection and Isolation via Pseudorange Prediction Model based Test Statistics

  • Yoo, Jang-Sik;Ahn, Jong-Sun;Lee, Young-Jae;Sung, Sang-Kyung
    • 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.

Fault Detection and Isolation of Parallel Operation of Two Converters Using Zero Current Transformer Method (영상변류기 동작 방식을 이용한 2개의 컨버터 병렬 운전시 고장 탐지 및 분리)

  • 손승찬;성세진
    • The Transactions of the Korean Institute of Power Electronics
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    • v.5 no.4
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    • pp.409-416
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    • 2000
  • In case of operating two converters in parallel with ZCT operation method using one current sensor for fault tolerance by system characteristics, identifying fault detection and isolation is difficult of which converter is fault since the ZCT output is a difference of two converters' supply current when a converter has fault. This thesis suggest a fault detection and isolation method of converter in case of operating two converters in parallel for fault tolerant system and verified this suggested method through an experiment.

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