• Title/Summary/Keyword: Condition Monitoring

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Implementation of an Integrated Machine Condition Monitoring Algorithm Based on an Expert System (전문가시스템을 기반으로 한 통합기계상태진단 알고리즘의 구현(I))

  • 장래혁;윤의성;공호성;최동훈
    • Tribology and Lubricants
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    • v.18 no.2
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    • pp.117-126
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    • 2002
  • Abstract - An integrated condition monitoring algorithm based on an expert system was implemented in this work in order to monitor effectively the machine conditions. The knowledge base was consisted of numeric data which meant the posterior probability of each measurement parameter for the representative machine failures. Also the inference engine was constructed as a series of statistical process, where the probable machine fault was inferred by a mapping technology of pattern recognition. The proposed algorithm was, through the user interface, applied for an air compressor system where the temperature, vibration and wear properties were measured simultaneously. The result of the case study was found fairly satisfactory in the diagnosis of the machine condition since the predicted result was well correlated to the machine fault occurred.

Establishment of Criteria to Machine Trouble based on Condition Monitoring (상태감시를 기반으로 설비 트러블 발생에 대한 판정기준의 설정)

  • Kang In-Seon;Park Dong-Joon;Choi Jung-Sang
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.27 no.4
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    • pp.157-164
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    • 2004
  • Trouble prevention of facilities in operation process plays an important role for improving facilities productivity as production systemization is installed with development of facilities automatization. Condition monitoring predicts machine's internal changes by periodically recording vibration occurred in the machine. This article considers a method of establishing statistical criteria for facilities troubles by utilizing machine condition evaluation and operation limit standards of ISO 10816-3.

Tool Wear and Fracture Monitoring through the Sound Pressure in Turning Process (음압을 이용한 선삭작업에서의 마모, 파손 감시)

  • 이성일
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.04a
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    • pp.82-87
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    • 1997
  • In order to make unmanned machining systems with satisfactory performances, it is necessary to incorporate appropriate condition monitoring systems in the machining workstation to provide the required intelligence of the expert. This paper deals with condition monitoring for tool wear and fracture during turning operation. Developing economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique are proposed. The validity of the proposed system is confirmed through the large number of cutting tests.

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Direct Calculation For Large Deformation

  • Wang, Xin-Zhou;Lei, Qiu
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.97-100
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    • 2006
  • The paper proposes a condition that should be satisfied when using the combination with different carrier phase observations to get the high precision deformation value. If the condition is satisfied, on the basis of DC algorithm, when the deformation is relatively large (0.7m),high precision deformation value can be obtained.

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Strain-based structural condition assessment of an instrumented arch bridge using FBG monitoring data

  • Ye, X.W.;Yi, Ting-Hua;Su, Y.H.;Liu, T.;Chen, B.
    • Smart Structures and Systems
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    • v.20 no.2
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    • pp.139-150
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    • 2017
  • The structural strain plays a significant role in structural condition assessment of in-service bridges in terms of structural bearing capacity, structural reliability level and entire safety redundancy. Therefore, it has been one of the most important parameters concerned by researchers and engineers engaged in structural health monitoring (SHM) practices. In this paper, an SHM system instrumented on the Jiubao Bridge located in Hangzhou, China is firstly introduced. This system involves nine subsystems and has been continuously operated for five years since 2012. As part of the SHM system, a total of 166 fiber Bragg grating (FBG) strain sensors are installed on the bridge to measure the dynamic strain responses of key structural components. Based on the strain monitoring data acquired in recent two years, the strain-based structural condition assessment of the Jiubao Bridge is carried out. The wavelet multi-resolution algorithm is applied to separate the temperature effect from the raw strain data. The obtained strain data under the normal traffic and wind condition and under the typhoon condition are examined for structural safety evaluation. The structural condition rating of the bridge in accordance with the AASHTO specification for condition evaluation and load and resistance factor rating of highway bridges is performed by use of the processed strain data in combination with finite element analysis. The analysis framework presented in this study can be used as a reference for facilitating the assessment, inspection and maintenance activities of in-service bridges instrumented with long-term SHM system.

A Study on Discrete Hidden Markov Model for Vibration Monitoring and Diagnosis of Turbo Machinery (터보회전기기의 진동모니터링 및 진단을 위한 이산 은닉 마르코프 모델에 관한 연구)

  • Lee, Jong-Min;Hwang, Yo-ha;Song, Chang-Seop
    • The KSFM Journal of Fluid Machinery
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    • v.7 no.2 s.23
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    • pp.41-49
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    • 2004
  • Condition monitoring is very important in turbo machinery because single failure could cause critical damages to its plant. So, automatic fault recognition has been one of the main research topics in condition monitoring area. We have used a relatively new fault recognition method, Hidden Markov Model(HMM), for mechanical system. It has been widely used in speech recognition, however, its application to fault recognition of mechanical signal has been very limited despite its good potential. In this paper, discrete HMM(DHMM) was used to recognize the faults of rotor system to study its fault recognition ability. We set up a rotor kit under unbalance and oil whirl conditions and sampled vibration signals of two failure conditions. DHMMS of each failure condition were trained using sampled signals. Next, we changed the setup and the rotating speed of the rotor kit. We sampled vibration signals and each DHMM was applied to these sampled data. It was found that DHMMs trained by data of one rotating speed have shown good fault recognition ability in spite of lack of training data, but DHMMs trained by data of four different rotating speeds have shown better robustness.