A Geometric Approach for Determining Exact Point Accessibility of Robotic Manipulations

Abstract

This paper presents a method of determining the exact point accessibility for an articulated manipulator with joint limits in both the regional and wrist structures. The method is based on the derivation of constraint equations, which define boundary curves on the service sphere separating accessible and non-accessible regions. These constraint equations are defined individually in each specially selected coordinate frame, called the “neutral coordinate frame.” The boundary curves on the service sphere may arise from both regional structure joint limits and wrist joint limits. The resulting constraint equations are solved numerically, and the accessibility regions of any given point can be plotted on its service sphere automatically. The method is demonstrated on a simple articulated manipulator with an Euler angle wrist. [S1050-0472(00)00103-3]