• Journal of Welding and Joining
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• v.20 no.6
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• pp.776-782
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• 2002

The experimental model of arc sensor in $CO_2$ arc welding has been individually developed according to welding condition and welding procedure. Therefore, the development of new arc sensor having the features of all conventional arc sensor is important in point of its application to various welding environment. In this study, the arc sensor experimental models comprised of a regression model and noise term were formulated using conventional arc sensing algorithm such as current area difference, current integration difference and weaving end current difference method, and their features were observed. The new regression arc sensor model was suggested using multiple linear regression analysis using current variables as independent variables of regression analysis. The artificial neural network model was also suggested where current variables and offset distance was used input/out variables of input/output node.

• Proceedings of the KIEE Conference
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• summer
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• pp.602-603
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• 2004

전력용 변압기에 아크나 코로나가 발생하여 국부가열이 존재하면 절연유나 절연지가 분해하여 저분자의 탄화수소, 수소, 탄화가스, 일산화탄소 둥이 발생하여 절연유에 용해된다. 절연유에 용해된 가스를 실시간 분석하여 변압기의 이상을 조기에 발견하여 운전의 효율성을 높이고 고장을 사전에 예방하기 위한 기술이 전개되고 있다. 경제적인 측면에서 단일 수소가스 검출센서가 널리 보급되어 실용화되고 있는 실증이다. 이 논문에서는 전력용 변압기의 국부적 고온인 경우의 가열온도, 가열시간 및 방전에 대하여 수소가스 주도형 센서의 응답특성에 관하여 고찰하였다.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.797-800
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• 1992

Much experience and knowledge is needed in welding because there are many working parameters and quantitative description is difficult. Therefore, introduction of expert system based on such data base has been required. In this study, welding heat and shape of bead was controlled by fuzzy inference with the welding condition, position error and voltage and current error of robot. For this, torch trajectory of robot was generated by modeling the working data with CAD and then welding was carried out through down loading to robot. And working error was controlled by on-line communication.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.461-462
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• 2013

In this paper, a studied the SAW system being developed shipbuilding and plant industry with changing welding method to progress productivity. It studies a SAW system using one sensor instead previous one which is using two sensors. It suggests SAW system which has AC output with high current makes high speed welding and DC output with accurate arcing makes detailed control.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.492-494
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• 2011

전력설비 증가와 더불어 GIS 사용이 확대되고 있는 상황에서 GIS 내부고장 발생시 복구 지연으로 인한 사례가 지속 발생하고 있다. 이를 예방하기 위해 170kV GIS 고장구간 판정시스템용 압력센서를 개발하고 검증을 위해 실사용 GIS 2대를 이용하여 내아크 시험을 수행한 결과이다. 시험을 통해 고장시 GIS 탱크 내부의 압력, 온도, 압력파를 측정하였고 SF6 Gas 배관과 연결된 현장조작함(LCP)내 가스주입구에 설치한 압력센서의 동작유무을 검증하였다. 시험결과 유동해석(CFD) 등 시뮬레이션 예측보다 압력 및 온도 상승이 높게 측정되었고 제품에 대한 신뢰성과 확대적용 가능성을 확인할 수 있었다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.14-23
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• 2007

Welding fabrication invariantly involves three district sequential steps: preparation, actual process execution and post-weld inspection. One of the major problems in automating these steps and developing autonomous welding system is the lack of proper sensing strategies. Conventionally, machine vision is used in robotic arc welding only for the correction of pre-taught welding paths in single pass. However, in this paper, multipass tracking more than single pass tracking is performed by conventional seam tracking algorithm and developed one. And tracking performances of two algorithm are compared in multipass tracking. As the result, tracking performance in multi-pass welding shows superior conventional seam tracking algorithm to developed one.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.301-302
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• 2006

In this paper, the possibilities of the Infra-red sensor in sensing and control of the bead geometry in the automated welding process are presented. Infra-red sensor is a well-known method to deal with the problems with a high degree of fuzziness so that the sensor is employed to build the relationship between process variables and the quality characteristic the proposed above respectively. Based on several neural networks, the mathematical models are derived from extensive experiments with different welding parameters and complex geometrical features. The developed system enables to select the optimal welding parameters and control the desired weld dimensions during arc welding process.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.339-340
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• 2019

전력사용량이 산업 발전과 더불어 기하급수적으로 증가하고 있으며, 한정된 공간 내에서 대용량의 전력설비를 설치하기 위해 폐쇄형 배전반이 운영되고 있다. 통계에 의하면, 고압 이상 전기설비 검사 결과 절연내력이 불합격인 경우가 다수 발생하고 있다. 특히 수배전반의 경우 부하설비 또는 외부의 영향을 확인할 수 있는 장치 및 보호설비가 설치되어 있으나 자체 안전장치가 마련되어 있지 않아 자체 사고를 신속히 검출하고 판단할 수 있는 기술이 필요하다. 본 논문에서는 열 감지 센서에 고속 디지털 신호 처리를 2차원 보간법으로 해상도를 올려서 사용하는 기술을 이용하여 아크플래시에 의해 발생되는 열 특성을 검출할 수 있는 장치 개발을 위한 기초 특성 조사를 실시하였다.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.923-928
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• 2003

This paper presents the motion control of a mobile robot with arc sensor for lattice type welding. Its dynamic equation and motion control method for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven along a straight line or comer. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider controls. For the torch slider control, the proportional integral derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the comer with range of $90^{\circ}$ constrained to the welding speed. The proposed control methods are proved through simulation results and the results have proved that the mobile robot has enough ability to apply the lattice type welding line.

• Journal of Sensor Science and Technology
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• v.25 no.3
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• pp.208-212
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• 2016

In this work, a loop sensor for Arc-Flash detections has been developed in order to trip a circuit breaker within 2.5 ms after an Arc-Flash event. For an efficient capturing of the flash light, plastic optical fibers, where light attenuations are larger than those in silica-based ones, with different diameters and surface conditions were utilized. The performance was comparatively analyzed with those of a point sensor and a commercialized product. The point sensor module was designed for hemisphere-like capturings of Arc-Flashes larger than 3 kA at 2 meters from the sensor. On the other hand, the loop sensor allowed 360-degree-detections around the fiber axis and the measurement range was dependent on the length of the fiber connected to the sensor module. The trip-level-dependent brightness measurement results showed that the fabricated point sensor and loop sensor satisfied a brightness condition, 10~40 klux, and the responses of the system to Arc-Flashes were completed within 2.5 ms.