Development of a panel welding robot system for subassembly in shipbuilding utilizing a two-dimensional CAD system

The robots used in factory automation systems have to be taught to perform their operation in either of the following two ways in advance: on-line teaching and offline teaching. Because off-line teaching does not require stopping the production line, the use of off-line teaching has bean increasing. Off-line teaching, however, requires a certain amount of the operator’s workload. Neither of these two ways can be applied to production lines for non-repetitive products such as ships because the robots have to be taught a different operation every time a new workpiece comes into the line. To overcome these difŽ culties, Kawasaki Heavy Industries Ltd (KHI) has developed an automated off-line teaching system. In this system, a computer automatically generates robot numerical control (NC) data which describes the action of the robot, eliminating the operators involvement. This new system, named ‘KCONG’ (Kawasaki Common Off-line NC data Generator), was actually applied to several automatic welding systems. In order to generate and verify NC data automatically, three-dimensional (3D) structural information of the workpiece is required because the movement of the robot has to be simulated to validate no collisions between the robot and the workpiece. The use of 3D system is gradually increasing, but it has not yet been sufŽ ciently diffused.