Solution and Application of Two Inverse Kinematics Subproblems

This paper presents two new inverse kinematics subproblems. Subproblem 1: rotating about two parallel axes to a given point and subproblem 2: rotating sequentially about two parallel axes to a point at the same distance to two given points. Subproblem 2 can be regarded as the extension of subproblem 1. The solutions to that kind of subproblem are derived. The inverse kinematics problem of some kinds of mechanic chains with two parallel rotate axes can be converted to solve those two subproblems and others known. Based on the RRSR chain, steps of inverse kinematics solution of this kind of chain are listed, and the problems of the multi-solution are analyzed and the geometric meanings of inverse kinematics are explained. Through an instance with exact parameters, the feasibility of the method is also testified