Analytical Inverse Kinematic Solutions for End-Effector Positioning and Pointing Applied to Revolute Manipulators with Spherical Wrists

摘要

This paper describes an analytical inverse kinematic solution for the functionally redundant task of both positioning and pointing the end-effector of a manipulator comprised of a three degree-of-freedom revolute arm possessing a three degree-of-freedom spherical wrist. This analytical solution is built upon an existing solution that is used for both positioning and orienting the end-effector of this type of manipulator. However, pointing is very different from orienting from a kinematic perspective. Therefore, the paper describes the kinematics of pointing and parameterizes the infinite number of pointing solutions to this problem in terms of a single free-parameter. The paper shows how these kinematic results are incorporated into the inverse kinematics problem for both positioning and orienting which leads to an analytical technique for both positioning and pointing. This general solution technique is then applied to an actual manipulator and inputs and outputs to the analytical solution method are tabulated and graphically presented.