Efficient Cable Path Optimization Based on Critical Robot Poses for Industrial Robot Arms

Abstract

Although industrial robotic arms are equipped with external cables to supply electricity, gases or other materials, cable path design is a difficult and demanding task. Herein, an efficient optimization method is proposed for automating cable path design under the assumption that the robot motion path is known. The contribution of this study was to reduce the considerable computation time required for the optimization, which was a concern in our previous work. The previous method represented candidates for cable paths as a set of parameter vectors (PVs) that included cable length and guide configurations, and then selected the optimal PV that satisfies stress constraints and provided the shortest cable path. The proposed method extracted critical poses, i.e., several static robot poses that are prone to applying stress to the cable, from the joint angle time series of the motion path, and then performed attachment and motion tests. The cable geometry for the static critical poses was simulated in the attachment test, while the geometry for dynamic robot motion was simulated in the motion test in an ascending order of the cable length among the PV candidates. Experimental results showed that the computation time for cable path optimization could be significantly reduced.