Development of a Multi-Robot Welding System for Sub-Assembly in Shipbuilding

Abstract

Several off-line teaching robot-welding systems for shipbuilding were developed in these ten years. These systems have been used mainly at sub-assembling stages in shipyards and utilize several robots and the geometrical design data in three-dimensional CAD. However, the systems usually have less efficiency in robot utilization due to the interference of robots, less adaptability to various types of ships, and less compliance with contingencies in daily operation such as robot malfunction and schedule change. Understanding these disadvantages of conventional robot welding systems, the authors have overcome these in developing a new off line teaching robot-welding system with four robots. High efficiency in robot utilization has been achieved by carefully designed locations of robots avoiding the interference of robots. Moreover, the robot can detect interference with another robot in advance and skip the welding line. It also can detect the malfunction of other robots next to it and carry out the welding that the troubled robots should have done. The robot welding can be applied to multi-layer welding with Hyper Arc Sensor for tracing the weld line and detecting the end of line. These development items have made the newly developed system efficient in robot utilization, adaptable to various types of ships, and compliant with robot malfunction and schedule change.