• Journal of Welding and Joining
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• v.27 no.2
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• pp.57-62
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• 2009

This research was carried out to improve the productivity in the subassembly process of shipbuilding through optimal work planning for the shortest work time. The work time consist of welding time, moving time of gantry, teaching time of robot and robot motion time. The shortest work time is accomplished by even distribution of work and the shortest welding sequence. Even distribution of work was done by appling the simple algorithm. The shortest work sequence was determined by using GA. The optimal work planning decreased the total work time of the subassembly process by 4.1%. The result showed the effectiveness of the suggested simple algorithm for even distribution of work and GA for the shortest welding sequence.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.18-20
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• 2004

This study is to find the optimal work plan of robot welding in the subassembly process of shipbuilding and to verify the found solution through 3-D simulation. The optimal work plan was established by evenly distributing the work amount to each stage and finding the shortest work sequence. The shortest work sequence was found by using the genetic algorithm. The result was compared with the practically adopted case and verified through the 3-D simulation.

• Journal of Welding and Joining
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• v.28 no.5
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• pp.75-79
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• 2010

The Remote welding system(RWS) using $CO_2$ laser equipment has focusable distance of laser beam longer than 800 mm from workpiece and can deflect the laser beam by the scanner mirrors very rapidly. In the case of normal welding system based on robot, there is a limit to move the shortest path in short time and this causes interference between robot and workpiece. On the other hand, RWS is the optimized equipment to get big merits with advanced sequence of welding and short cycle time. However, there is still a pending task such as the control of plasma in the welding process of thick sheets therefore, it requires high power laser beam because of the absence of assist gas equipment in itself. In this study, high-tensile steel plates were overlap welded with $CO_2$ RWS for the production of car body and the influence of penetration depth according to the existence of assist gas was analyzed. Excellent tensile strength with enough width of molten zone independent to penetration depth was observed under welding condition with 3.6 kW laser power and 2.8 m/min welding speed without assist gas. Finally, the proto-type automotive parts were produced by applying the deduced optimal welding condition.