Novel method for welding gantry robot scheduling at shipyards

ABSTRACT

Welding is the most critical operation in the shipbuilding process and has a significant influence on the production cost and quality of ships. Therefore, the welding operation must be optimised. This paper presents a real-world welding gantry robot scheduling problem at shipyards, in which three gantry robots function in parallel. Welding gantry robots cannot cross each other and should operate over a certain distance to avoid collisions. To minimise the makespan, the welding tasks given by line segments should be evenly distributed among the three gantry robots. The welding tasks assigned to each robot should be optimally sequenced to minimise the completion time, including the waiting time required to prevent collisions with neighbouring robots. In addition, long welding edges are split, and the split small length edges are assigned to the gantry robots. This paper proposes a mixed-integer linear programming model, three-stage solution approach, and variable neighbourhood search algorithm to solve this problem. Experimental tests conducted on 20 real problem instances revealed that the proposed approach can reduce the makespan by 14% on average when compared with the conventional method.

KEYWORDS:

• Welding gantry robot
• scheduling
• shipbuilding
• heuristics
• mixed-integer linear programming

Data availability statement

The data that support the findings of this study are available from the corresponding author, B.-I. Kim, upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [grant numbers 2022R1A2C2006665 and 2022R1A4A1019071].

Notes on contributors

Jongsung Lee

Jongsung Lee is an Assistant Professor in the Department of Industrial and Management Engineering at Korea National University of Transportation (KNUT), Korea. He received his B.S and Ph.D. (Integrated Master & Ph.D.) degrees in Industrial and Management Engineering from Pohang University of Science and Technology (POSTECH), Korea, in 2005 and 2015, respectively. He was a senior researcher and engineer in the Division of Device Solutions (Semiconductor) at Samsung Electronics, Korea. He is a member of KIIE and KORMS. His research interest includes bin packing problems, vehicle routing problems, and OHT (Overhead Hoist transport) routings.

Byung-In Kim

Byung-In Kim is a Professor and the Head of the Department of Industrial and Management Engineering at POSTECH, Korea. He received his B.S. and M.S. degrees in Industrial Engineering from POSTECH, Korea, and Ph.D. degree in Decision Sciences and Engineering Systems from Rensselaer Polytechnic Institute, Troy, New York, in 1991, 1994, and 2002, respectively. He was an Assistant Professor of Industrial and Systems Engineering at the University of Memphis and the Director of Research and Development at Institute of Information Technology, Inc., The Woodlands, Texas. His research interests include vehicle routing problems, industrial optimization problems, traffic signal optimization, and logistics. He received the 2004 Franz Edelman Finalist Award from INFORMS, 2013 Hyun-Woo Management Science Award from the Korean Operations Research and Management Science Society, and 2018 POSCO Smart Innovation Award from POSCO. He is an associate member of the National Academy of Engineering of Korea, fellow of Asia Pacific Industrial Engineering and Management Society, and vice president of the Korean Institute of Industrial Engineers. He has more than 65 papers published in international journals such as International Journal of Production Research, European Journal of Operational Research, and IISE Transactions.

Mihee Nam

Mihee Nam is a senior engineer at Samsung Heavy Industries, Korea. She received her B.S. degree in Mechanical Design Engineering from Chungnam National University, Korea, in 2001 and M.S. degree in Mechanical Engineering from Yonsei University, Korea, in 2003. She received her Ph.D. in the Robotics Related Interdisciplinary Course from Pusan National University, Korea, in 2017. She received the Engineer of Korea Award from the Ministry of Science and ICT, Korea, in 2018. Her research interests include robotic control and automatic system control.