Analytical Solutions for Two-Contact Whole-Arm Manipulation Inverse Kinematics for Manipulators with Link Offsets

Pascal Hinrichs, Minh Tam Vu, Max Pfingsthorn, Christian Kowalski, Andreas Hein

Abstract: Whole-arm manipulation (WAM) is an ideal way to manipulate large and heavy loads. Whole-arm configuration generation algorithms are always constructed for a specific manipulator type. However, through increased transferability between types, advances in whole-arm manipulation could be applied more easily and developed to other manipulators. We therefore present two algorithms for transferring a whole-arm configuration from a manipulator without link offsets to one with link offsets in the elbow and wrist in this work. Both are analytical, where one can be solved algebraically, the other one only numerically. We show the advantages and disadvantages of these two variants and compare them with a memetic evolution algorithm as a baseline. It is shown that our algorithms require only about one thousandth of the computational time and achieve a significantly smaller variance in the joint position solutions.