Robot Collision Checking Method for Welding Automation in Ship Block Construction

The welding process is the most time and cost consuming operation, and weld quality is also a critical issue in the shipbuilding process. To address these challenges, welding automation has been widely implemented. The sub-assembly process involves welding stiffeners to the base plate. Since a large number of stiffeners must be attached to the plate, this process requires significant time and cost, making it a key target for welding automation. For automated welding, it is necessary to generate robot paths and to avoid collisions during operation. This study proposes an interference detection method for the automation of subcomponent welding in ships, based on CAD models. A lightweight CAD model, typically used for visualization purposes, is utilized, and surfaces where interference occurs are extracted to enable rapid collision checks. Furthermore, as most welding paths are linear and the robot maintains a fixed posture during welding, a swept shape that reflects this constant posture is generated for inspection. The proposed algorithm was validated through application to actual manufacturing processes.