Development of multi-axis gantry type welding robot system using a PC-based controller

In order to implement factory automation in ship building industry, we have developed a multi-axis gantry type welding robot system for automated fabrication of subassemblies of ship building and steel bridge lines. This automatic welding system consists of a 4-axis gantry-type robot with two welding robots over-hanged from it. A gantry robot is controlled by PC based controller(called PC-RC;PC-based Robot Controller) and two welding robots are controlled by their controllers(called RCs;Robot Controllers), respectively. Following the movemoments of gantry robot to the designated point of work-piece to be welded, the two welding robots perform welding on the both sides of work-piece simultaneously. Synchronizing signals between PC-RC and RCs for moving are performed by digital in-out signals. The job programs for both gantry and the robots are generated by OLP(Off-line Programming) system. Also the PC-RC receives the job programs of gantry and the welding robots from OLP systems via LAN(Local Area Network). The PC-RC also sends job programs of the welding robots to the RCs via serial communication lines. The resultant system was field-tested at the test shop and its performance was proved to be successful.