The utilization of a positioner for robot welding process planning

Presented in this paper is the utilization of a positioner in a robot arc welding system to increase the quality and the productivity of the system. It is well known that downhand or flat position welding is essential for fine quality of arc welding. A positioner having more than two degress of fredom can perform the downhand welding by making normal vectors of weldline be parallel with the direction of gravity. First, inverse kinematics of the positoner to make the downhand welding system is derived and graphically simulated. Secondly, interrelation- ship between each pair of torch orientation, weld quality, and weld productivity is mathematically modeled and examined using a stable area and a stability function. Finally, process planning procedures for multi-weldine/multi-layer weldings are proposed to demonstrate the usefulness of aforementioned methods.