• 한국레이저가공학회지
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• 제8권3호
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• pp.27-30
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• 2005

Nowadays, most automotives companies are making use of laser welding in car body assembly shop. But even though laser welding is better than resistance spot welding in many points, its application has been limited to special technology for manufacturing. The paper introduces in the field of remote welding system (RWS) to improve the process efficiency of laser welding. Positioning time of RWS between welding stitches is dramatically reduced to zero. It is a kind of solutions to generalize laser welding in mass production. This RWS consists of fiber laser, industrial robot and 3-axis scanner.

• 제어로봇시스템학회논문지
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• 제5권3호
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• pp.344-352
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• 1999

There has been requested to automate the welding process in shipyard due to its dependence on skilled operators and the inferior working environments. According to these demands, multiple robot welding system for sub-assembly welding line has been developed, realized and installed at Keoje shipyard. In order to realize automatic welding system, robots have to be equipped with a sensing system to recognize the position of the welding panels. In this research, a camera vision system(CVS) is developed to detect the position of base panels for sub-assembly line in shipbuilding. Two camera vision systems are used in two different stages (fitting and welding) to automate the recognition and positioning of welding lines. For automatic recognition of panel position, various image processing algorithms are proposed in this paper.

• 대한산업공학회지
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• 제25권1호
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• pp.21-34
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• 1999

We consider a scheduling problem arising in a shipyard subassembly welding process. There are four welding robots of gantry type, which perform the welding process for the subassemblies. Because the robots perform the welding operations at the same time, there is a possibility of collision between adjacent robots depending on the welding schedule. In this paper, we propose a heuristic method to find a welding schedule which does minimize the welding completion time while avoiding collision among the robots. The method consists of two phases: assignment and scheduling. In the assignment phase, we assign each welding line to a proper robot. In the scheduling phase, we determine the welding schedules for the robots so that collision is avoided. Computational experiences with the data which reflect the real situation are reported.

• 한국기계가공학회지
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• 제15권5호
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• pp.31-38
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• 2016

This study proposes an optimal design for a robotic welding system for a high-strength steel armor plate. In order to identify the welding defect parameters, we analyzed the 4M (man, machine, materials, method) characteristics diagram, as well as a cause and effect matrix, to improve the productivity and quality of welding defects. From these analyses, we designed optimal welding conditions and carried out welding tests -- such as mechanical testing and macro structure tests - with positive results. We determined that it was possible to obtain a quality similar to manual welding with our robotic welding system. In the future, we expect that the system will be used as inspiration for future welding system designs.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.643-648
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• 2005

Generally, ships have marks of various shapes on outside of the hull. Among them, so called "Draft Mark" indicates the distance from the bottom of the keel to the waterline. Draft marks are used to determine the displacement and other properties of the ship for stability and control purposes. These marks are made up of welding bead or sticking the steel plate on outside of the hull. To improve the confidence level of the ship owner, quality and accuracy of the draft mark is very important. So the automatic mark welding robot is used to enable a high quality and accurate manufacturing line. To improve the system portability, the system is divided into two distinct parts, namely mechanical part and control part. Mechanical part is robust, a lightweight, and easy to dismantle. The control part consists of an in-house developed controller, which is based on embedded Linux. Also, the control part consists of power line communication module to ensure the applicability of the controller in manufacturing line. In this paper, the methodologies of control and configuration of the robot are discussed.

• 한국정밀공학회지
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• 제13권1호
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• pp.131-142
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• 1996

Most industrial robots cannot be off-line programmed to carry out a task accurately, unless their kinematic model is suitably corrected through a calibration procedure. However, normal calibration is an expensive and time-consumming precedure due to the highly accurate measurement equipment required and due to the significant amount of data that must be collected. This paper presents a simple and economic procedure to improve the efficiency of robot calibration especially for arc welding application. To simplify the measurement process, an automotic data measurement algorithm as well as a simple measurement device are developed. Also, a calibration algorithm which can automatically identify the independent model parameters to be estimated is presented. To demonstrated the simplicity and the effectiveness of the procedure, experimental studies and computer simulations are performed and their results are discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2497-2499
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• 2002

This raper proposes a simple robust nonlinear controller design method based on Lyapunov stability for tracking reference welding trajectory and velocity of a three wheel welding mobile robot (WMR). Control law is obtained from Lyapunov control function to ensure asymptotical stability of the system. The effectiveness of the proposed controller is shown through simulation results.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2005년도 추계학술대회 및 정기총회
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• pp.113-121
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• 2005

Virtual Manufacturing is a powerful methodology for developing a new product, new equipment and new production system. It enables us to check the errors in design before production. This paper deals with a case study of virtual manufacturing in an excavator factory. Boom and rotating table of upper body are selected for application. 3D models of parts and fixtures are developed with CATIA and 3D simulation models are developed with IGRIP. These models are used for the design of fixture to verify the motion of the equipment. As a result, the manual welding systems are replaced by automatic systems and many design errors are corrected in the design phase, which enables us to reduce the developing cost and time.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1201-1206
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• 2007

Robot simulation technique is essential not only for robot developers to design robotic systems but also for robot operators to predict robot motion, configure system layout, and increase robot ability. However, commercial robot simulation software such as ROBCAD, IGRIP, and so on are expensive and sometimes they are difficult to customize into industrial purpose programming for users. Therefore, user-based simulation programming is required to magnify the efficiency of robot system. In this paper, we show the methodology of developing user-based robot simulation programming using PC(personal computer), Open-Inventor, and Windows Programming. The developed programming has been successfully applied to welding robot systems of a shipbuilding industry. Also, the methodology presented here can be easily extended to simulate manipulators of other typed mechanism on user's PC.

• 동력기계공학회지
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• 제18권4호
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• pp.97-103
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• 2014

In this paper, the authors consider a robot motion control to cope with painting, welding jobs and etc. Especially, a method for easy recognition and regeneration of the robot motions made by the operator is proposed. The method is based on the process of accurate modelling, controller design and experimental evaluation. In this study, the model and controller for all motions are obtained individually, where the control system is designed on the robust control framework. And the experiment result with good control performance is presented.