Abstract

The main objective of this paper is to develop a redundancy-resolution algorithm to optimize the joint motion of a redundant robotic welding system. At first, the Joint Limit Avoidance (JLA) and Singularity Avoidance (SGA) optimizations are employed. Due to complicated geometry of the welding path, despite using JLA & SGA optimizations, some constraints like joint angles violate their allowable limits. Hence, functional redundancy (FNR) is employed as the best solution because it has no effect on the welding electrode direction. In this paper, the functional redundancy is used as an augmented task, which changes the desired path without effecting the electrode direction. To select the best functional redundancy angle, two indexes, i.e. the minimum joint angles movement and the singularity indexes, are introduced. Simulation results show that the planned path using FNR not only satisfies all constraints, but it also is smooth.