Implementation of Robots in Spot Welding Process

Abstract

Within industry many repetitive operations, such as pick and place, spot welding, and spraypainting, have been successfully automated. While the operations themselves are diverse, a common thread within nearly all of them is that the robot performing the task. From a control perspective, this means that the robot need only be controlled to follow a desired task.Robots are well-established in the material processing industry. They are used for cutting, welding and marking of work pieces made from diverse materials. In these applications it is important to move the focal spot of the welding exactly along the desired machining contour on the work piece. Due to their mechanical inertia, robot arms can not perform abrupt changes of velocity (direction and magnitude) even though this is frequently required in machining operations. In this paper a automation technique is proposed, which is intended to partly overcome the limitations of doing the same work by using manpower. The paper describes control strategy ,which is based on plc automation and a real time interface to a standard robot controller. Simulation-based and experimental results are presented and the performance of the control strategy in various test scenarios is described