• Title/Summary/Keyword: Failure detection

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An Experimental Study onthe Detection of Tool Failure I Face Milling Processes (정면밀링가공시 공구 파손 검출에 관한 실험적 연구)

  • 김우순
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.5 no.3
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    • pp.73-79
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    • 1996
  • In this paper present a new technique (strain-telemetering)for detection of coated tool failure in face milling processes. In the cutter body the strain signals received fro the transmitter is transformed in to frequency modulation(FM) signals in face milling processes. A receiver which is place near by the Vertical milling machine receives the FM signals, then the signals will be sent to a computer which determines whether th tool is failure. And machined surface of workpiece is detected by the SEM. In this paper, A on-line monitoring of the tool failure detection system based on the strain -telemetering apparatus has bee represented.

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An Experimental Study on the Detection of Tool Failure Using Telemetering Technique (텔레미터링기법을 이용한 공구 파손 검출에 관한 실험적 연구)

  • Kim, W.S.;Lee, J.H.;Kim, D.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.11
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    • pp.100-105
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    • 1996
  • In this paper presents a new technique (stain-telemetering) for detection of coated tool failure in face milling processes. In the cutter body, the strain signals received from the transmitter are transformed into frequency modulation(FM) signals in face milling processes. The receive which is placed near by the Vertical milling machine receives the FM signals, then the signals are sent to a computer, which shows the tool failure. In this paper, A on-line monitoring of the tool failure detection system based on the strain-telemetering apparatus has been represented.

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Actuator and sensor failure detection using direct approach

  • Li, Zhiling;Nagarajaiah, Satish
    • Structural Monitoring and Maintenance
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    • v.1 no.2
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    • pp.213-230
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    • 2014
  • A novel real-time actuator failure detection algorithm is developed in this paper. Actuator fails when the input to the structure is different from the commanded one. Previous research has shown that one error function can be formulated for each actuator through interaction matrix method. For output without noise, non-zero values in the actuator functions indicate the instant failure of the actuator regardless the working status of other actuators. In this paper, it is further demonstrated that the actuator's error function coefficients will be directly calculated from the healthy input of the examined actuator and all outputs. Hence, the need for structural information is no longer needed. This approach is termed as direct method. Experimental results from a NASA eight bay truss show the successful application of the direct method for isolating and identifying the real-time actuator failure. Further, it is shown that the developed method can be used for real-time sensor failure detection.

A Study of FDIR S/W Design and Verification for Gyro Sensor of COMS Satellite (통신해양기상위성 자이로센서 FDIR 설계 및 검증에 관한 연구)

  • Lee, Hoon-Hee
    • Aerospace Engineering and Technology
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    • v.7 no.2
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    • pp.95-102
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    • 2008
  • COMS Satellite is automatically able to recover from any defined failure thanks to a full redundancy. This study assesses the effects of gyro failure on the COMS mission and analyzes the mechanism of Gyro Failure Detection, Isolation and Recovery about failure detection means, isolation and recovery actions and their consequences. At last, it checks the FDIR behavior from an injected failure on COMS simulator.

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An Experimental Study on the Tool Failure Detection in the Machining by Face Milling (정면밀링 가공시 발생하는 공구파손 검출에 관한 실험적 연구)

  • Seo, Jae-Hyung;Kim, Seong-Il;Kim, Tae-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.3
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    • pp.92-100
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    • 1995
  • This experimental study is mainly investigated on the mean cutting forces and AE(acoustic emission) parameters in order to detect and estimate the tool failure in the pachinig of SUS304 by face milling Mean cutting forces and AE parameters can detect the tool failure in face milling. Effective detection parameters are AE RMS, AE energy, AE count, AE duration, and z-direction mean cutting force. From the analysis of cutting tool failure detection, the tool failure of face milling is caused by sudden increasing of the cutting force.

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A study on the sensor failure detection and diagnosis in the stochastic system (잡음이 존재하는 선형 시스템에서의 센서 고장감지에 대한 연구)

  • 손성한;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.437-440
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    • 1989
  • In the paper a failure detection and diagnosis method of a stochastic system is proposed. It is based on the comparison of the moving averages generated from outputs of the real plant and a modeled normal plant. The proposed method allows us to locate the failed sensor and can be efficiently used for the failure detection and diagnosis of a plant with many sensors.

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A Risk Metric for Failure Cause in FMEA under Time-Dependent Failure Occurrence and Detection (FMEA에서 고장발생 및 탐지시간을 고려한 고장원인의 위험평가 척도)

  • Kwon, Hyuck Moo;Hong, Sung Hoon;Lee, Min Koo
    • Journal of Korean Society for Quality Management
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    • v.47 no.3
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    • pp.571-582
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    • 2019
  • Purpose: To develop a risk metric for failure cause that can help determine the action priority of each failure cause in FMEA considering time sequence of cause- failure- detection. Methods: Assuming a quadratic loss function the unfulfilled mission period, a risk metric is obtained by deriving the failure time distribution. Results: The proposed risk metric has some reasonable properties for evaluating risk accompanied with a failure cause. Conclusion: The study may be applied to determining action priorities among all the failure causes in the FMEA sheet, requiring further studies for general situation of failure process.

Reliability Analysis of Repairable Systems Considering Failure Detection Equipments (고장감지장치를 고려한 수리가능 시스템의 신뢰도 분석)

  • Na, Seong-Ryong
    • The Korean Journal of Applied Statistics
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    • v.24 no.3
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    • pp.515-521
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    • 2011
  • In this paper we consider failure detection equipment that which find failures in repairable systems and enable repair operations. In practical situations, failure detection equipment may come across troubles that can cause the omissions in detecting system failures and have a serious effect on system reliability. We analyze this effect through the appropriate modeling of Markov processes.

Sensor Failure Detection and Accommodation Based on Neural Networks (신경회로망을 이용한 센서 고장진단 및 극복)

  • 이균정;이봉기
    • Journal of the Korea Institute of Military Science and Technology
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    • v.1 no.1
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    • pp.82-91
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    • 1998
  • This paper presents a neural networks based approach for the problem of sensor failure detection and accommodation for ship without physical redundancy in the sensors. The designed model consists of two neural networks. The first neural network is responsible for the failure detection and the second neural network is responsible for the failure identification and accommodation. On the yaw rate sensor of ship, simulation results indicates that the proposed method can be useful as failure detector and sensor estimator.

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