A COMPLETE KINEMATIC ANALYSIS OF 4-REVOLUTE-AXIS ROBOT MANIPULATORS

The approach taken in this research is to study the kinematics of low-number-of-axes robots and apply new results to progressively more complex geometries. The kinematic analysis in this paper provides valuable insight in the inverse kinematic study of all-revolute-4-DOF robot arms and leads to special 4-DOF structures with more than one inverse kinematic solution set. These special structures can be of valuable assistance in the design of 4-DOF robot manipulators. This paper also provides an essential theoretical foundation for solving 5- and possibly 6-DOF manipulators. A companion paper builds on this foundation to prove important properties and provide an efficient inverse kinematic technique suitable for real-time control of fast 5-DOF robot manipulators.