• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.293-297
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• 1992

For the computerized monitoring and diagnosis of the undesirable chip chatter which are major obstacles to FMS, a pattern recognition system based on multi-layer perception neural network is developed and the performance of the system is experimentally evaluated. Experimental results show that recognition of the two class state of normal or abnormal cutting gives satisfactory results with success rate of 81`91%. Therefore, the proposed system has possibility for use in monitoring and diagnosis of automatic manufacturing system

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.5-16
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• 1994

NC 공작기계가 생산현장에 도입된 이래 이를 Computer와 연결함으로써 CAD/CAM/CAE의 결합이 실현되어가고 있다. 최근에는 CAD/CAM/CAE와 더불어 생산공정에 있었서 여러 대의 NC공작기계, 로보트, 운송장치를 결합하고 공구관리나 생산관리까지도 Computer를 이용하고자 하는 소위 CIM(Computer Intergrated Manufacturing)시스템에 관한 연구가 활발히 진행되고 있으며 여기에 생산가공 시스템의 상태 변화량의 감지를 통하여 공정상태를 종합적으로 감시, 진단할 수 있는 시스템(M & D : Monitoring and Diagnosis)에 대한 필요성도 증대되고 있다. 이는 생산 공정에 있어서의 궁극적 과제인 생산 자동화 혹은 무인 자동화의 가능성을 한층 높여준다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.5
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• pp.81-86
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• 2004

A fundamental study for developing a system of fault diagnosis of a pump is performed by using neural network. The acoustic signals were obtained and converted to frequency domain for normal products and artificially deformed products. The signals were obtained in various driving frequencies in order to obtain many types of data from a limited number of pumps. The acoustic data in frequency domain were managed to multiples of real driving frequency with the aim of easy comparison. The neural network model used in this study was 3-layer type composed of input, hidden, and output layer. The normalized amplitudes at the multiples of real driving frequency were chosen as units of input layer. Various sets of teach signals made from original data by eliminating some random cases were used in the training. The average errors were approximately proportional to the number of untaught data. The results showed neural network trained by acoustic signals can be used as a simple method for a detection of machine malfuction or fault diagnosis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.647-650
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• 2000

For the failure diagnosis of industrial system like various manufacturing systems, power plants and etc, many failure diagnosis approaches are considered. Here we are focus on the DES approach for failure diagnosis. We treats of failure recovery problem that is euly not mentioned in DES approach. The procedure to design a recoverable diagnoser is presented. And the recoverability, necessary and sufficient condition fur recoverability are defined. Then we make the high-level diagnoser to reduce the state size of recoverable diagnsoer. Finally, a pump-valve system example is presented.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.57-62
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• 2000

Diagnosis or measurements using Infrared thermoimage hasn't been available. A quick diagnosis and thermal analysis can be possible when that kind of system is introduced to the investigation of each part. In this study, Infrared Camera, Thermovision 900 was used in order to investigate. Infrared Camera usually detects only Infrared wave from the light in order to illustrate the temperature distribution. Infrared diagnosis system can be applied to various field. Also, it is more effective to analyze temperature distribution on the welding parts during welding process. Especially, diagnosis using Infrared camera plays an important role on thermal analysis of Axle Casing Nut for Commercial Vehicles.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1489-1492
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• 1997

To increase reliability and performance of an IMS(Intelligent Manufacturing System), fault tolerant control based on an accurate fault diagnosis is needed. In this paper, robot FDI(fault detection and identification) is proposed for IMS where the robot is controlled with state estimates of a nonlinear filter using a mathematical robot model. The Chi-square distribution is applied fault detection and fault size is estimated by a proposed bias filter. Performance of the proposed algorithm is tested by simulation for studies.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.2
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• pp.38-45
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• 1995

The diagnosis and monitoring system of abnormal cutting condition is necessary to realize precision machining proces and factory automation, which are final goal of metal cutting in order to develop this system, theimage processing technique has been investigated in machining process. In theis paper, the measurement system of tool wear using computer vision is designed to detect the wear pattern by non-contact and direct method and get the realiable wear information about cutting tool. We measured the area of the side and front part of the diamond core dril which is used in 40kHz ultrasonic vibration machine.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.5
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• pp.666-673
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• 1998

To increase reliability and performance of an IMS(Intelligent Manufacturing System), fault tolerant control based on an accurate fault diagnosis is needed. In this paper, robot FDI(fault detection and identification) is proposed for IMS where the robot is controlled with state estimates of a nonlinear filter using a mathematical robot model. The Chi-square test and GLR(General likelihood ratio) test are applied for fault detection and fault size is estimated by a proposed bias filter. Performance of the proposed algorithm is tested by simulation for studies.

• The Korean Journal of Applied Statistics
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• v.4 no.1
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• pp.65-83
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• 1991

In order to know the situation of statistical Quality Control in Korea, we have surveyedabout 4, 500 manufacturing companies in Korea. Among the first 4, 500 manufacturing companies, 2, 586 companies have answered for the questionairs of the sample survey. In this research a statistical analysis is conducted for the 2, 586 companies and diagnosis of the situation of Statistical Quality Control is Korea in presented in terms of levels of development and degrees of implementation.

• Korean Journal of Computational Design and Engineering
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• v.15 no.2
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• pp.94-105
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• 2010

Todays, there is fast transition about the new manufacturing IT methodologies from the conceptual phase into the practical application phase for the strengthening of enterprise competitiveness in manufacturing industry. One of those new methodologies is PLM (Product Life-cycle Management). PLM methodology consists of 3D CAD for the product design, PDM (Product Data Management) for the data management based on the collaboration platform and lastly DM (Digital Manufacturing). DM has evoluted from the stand-alone computer simulation of early 1980s, and now it covers the overall production development and production. Unfortunately, there exist serious critical problems about the actual application of DM for the real work. This is owing to the transition of the point of view from stand-alone type application (such as flow simulation or robot simulation) to that of business process about product development and production management. In this paper, we propose an application framework for the successful project with the digital manufacturing methodology with the concept of Information Strategy Planning, which enables the systematic diagnosis and the quantitative evaluation. Also, we introduce the actual practice of the proposing framework with the ISP project for 'Analysis & Simulation Technique of manufacturing process project' that is being conducted by Chungnam Techno Park.