Robotic welding system with parallel degrees of freedom

This paper considers some problems concerning robotic welding of large structures. If spot welding is applied, then the task consists of fast motions between welding points, and at each point the end effector stops and maintains position for a short time. Similar examples can be found in arc welding applications. Since large structures and, accordingly, large robots are considered, a significant problem appears when extremely nonuniform motion is required. One way to solve this problem is to introduce parallel degrees of freedom. Two methods for this distribution of motion to parallel degrees of freedom are discussed. The theory resulted in the design of a large portal robot with high dynamic capabilities.