A Comparative Study of Generalized Coordinates for Solving the Inverse- Kinematics Problem of a 6R Robot Manipulator

Abstract

This paper studies two different approaches to the inverse- kinematics problem for a six-degree-of-freedom robot manip ulator having three revolute joint axes intersecting at the wrist. One method uses three rotational generalized coordi nates to describe the orientation of the body. The other method uses equivalent Euler parameters with one constraint equation. These two approaches have been incorporated into two different computer algorithms, and the results from each are compared on the basis of computational complexity, time simulation, singularity, etc. It was found that Euler parame ters were less efficient than three rotational angles for solving the inverse-kinematics problem of the robot considered, and that the physical singularities caused by the robot mecha nism could not be eliminated by using either of the two ap proaches.