• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2701-2706
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• 2003

This paper describes weld seam tracking and error compensation methods of automatic plasma arc welding system designed for the corrugation panel that consists of a linear section and a curved section with various curvatures. Realizing automatic welding system, we are faced with two problems. One is a precise seam tracking and the other is an arc length control. Due to the complexity of the panel shape, it is difficult to find a seam and operate a torch manually in the welding process. So, laser vision sensor for seam tracking is equipped for sensing the seam position and controlling the height of a torch automatically. To attain more precise measurement of an arc length, we measure the 3D shape of the panel and analyze error factors according to the various panel states and caused errors are predicted through the welding process. Using that result, compensation algorithm is added to that of arc length control and real time error compensation is achieved. The result shows that these two methods work effectively.

• 전력전자학회논문지
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• 제8권5호
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• pp.397-406
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• 2003

저항 스폿 용접은 자동 용접라인 등에서 널리 사용된다. 최근에는, 대량으로 생산하는 산업현장에서 좀 더 정교한 품질 제어가 필요하게 되었고 마이크로프로세서를 채용한 제어의 다양한 적용으로 높은 생산성과 더 나은 용접품질을 얻을 수 있게 되었다. 본 연구에서는 인버터 타입 파우어 소스와 용접 서보건을 개발하였다. 그 결과, 기존의 공압건에 비해 몇 가지 장점을 갖게 되었는데 그 중의 하나는 용접공정 중에 정밀한 가압력 제어가 가능하게 되었다. 또한, 작업시간도 줄고 경비도 절감되는 부가 효과를 얻을 수 있다고 판단된다.

• 한국해양공학회지
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• 제25권6호
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• pp.1-8
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• 2011

This paper describes a new method for a digital gas metal arc welding (GMAW) system. The GMAW system is an arc welding process that incorporates the GMAW power source (PS-GMAW) with a wire feed unit (WFU). The PS-GMAW requires an electric power of constant voltage. A constant magnitude is maintained for the arc current by controlling the wire-feed speed of the WFU. A mathematical model is derived, and a self-tuning fuzzy proportional-integral-derivative (PID) controller is designed and applied to control the welding current. The electrode wire feeding mechanism with this controller is driven by a DC motor, which can compensate for both the molten part of the electrode and undesirable fluctuations in the arc length during the welding process. By accurately maintaining the output welding current and welding voltage at constant values during the welding process, excellent welding results can be obtained. Simulation and experimental results are shown to prove the effectiveness of the proposed controller.

• 한국생산제조학회지
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• 제6권2호
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• pp.92-101
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• 1997

The purpose of this welding process of the exclusive welding-machine using welding torch-rotation type is to develop a mechanism which can solve the problem of twisting of welding wires and cables. The technique was developed by revising the torch position and smooth controlling of both the normal and reverse rotation. Some of the advantages of using the torch-rotation type apply to the work-rotation technique are the practical uses of increased work space and link work with the factory automation system. Do apply the welding process, I designed and made a special unit so called torch part in order to solve the problems of kinematical. And I made a control panel which can manipulate the progress of the entire process at the work shop. Even if it will be applied to another kind of axle casing's welding work, this process can be utilized if other sizes of the fixed pin and work part is produced and changed. The development of this exclusive welding-machine could reduce the manpower of skilled welding labor and increase productivity and better quality product in comparison to the handmade product.

• Journal of Welding and Joining
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• 제32권1호
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• pp.102-107
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• 2014

SCR(Thyristor) type $CO_2$ welders have widely used for the welding process of heavy industries such as shipbuilding and plant. Since the industrial fields of shipbuilding and plant are usually exposed to severe welding condition with lots of dust, extreme temperature, high humidity and vibration, it is not recommended to use inverter type welder despite its state-of-the-art technology. Many sophisticated functions in the inverter welder may not work due to malfunction of its sensitive components. Hence this study focused on digitalization of SCR $CO_2$ welder by making use of microprocessor for SCR phase control. By this application, fine control of output of the $CO_2$ welding systems is achieved. Also pulse output mode of operation is realized and its verification is carried out with aluminum sample welding. The experimental results showed sound weld bead. The front operation panel provide user with numerical parameter settings and monitors. It will help precise weld process monitoring and control with digital value.

• Journal of Welding and Joining
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• 제31권1호
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• pp.26-32
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• 2013

Recently, welding technology of nonferrous metals which were difficult to implement by arc welder has become available through digitalization of arc welding machine. Among them, the welding quality improvement of aluminum welding is very noticeable. These results increase the arc stability by controlling arc current and voltage waveform precisely, and control wire feed speed by synchronizing with arc current which the feed rate of filler wire is controlled by a precise motor control of servomotor and not by a simple constant speed feeding. Not only through the hardware digitalization of arc welding machine but also through advance of software of arc welding, it became possible to implement a certain level of welding quality by a simple operation. These led to CMT welding process implementation which requires low heat input than current arc welding and highly increased the applicability of the aluminum welding.

• Journal of Welding and Joining
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• 제16권6호
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• pp.7-16
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• 1998

• Journal of Welding and Joining
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• 제23권3호
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• pp.31-33
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• 2005

• Journal of Welding and Joining
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• 제17권6호
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• pp.21-24
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• 1999

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.426-430
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• 2008

Hot shear-welding is a process of bonding two plates together by using shearing stress in a controlled manner. This study dealt with the hot shear-welding process of two aluminum plates. These two plates were piles up in the shear-welding mold. Due to the shearing stress, these two plates were cut off longitudinally, and meantime they were welded together. During this process the control of the surplus material flow is very important, and it can be realized by designing the overlapping length and the shape of the cavity. The commercial software Deform-3D was employed to predict the effect of these two factors. The overlapping length and the shape of the cavity that presents the optimum design was then developed to get a good shear-welding process.