Drive train configuration arrangement for gear coupled manipulators

This paper describes a methodology for the drive train configuration arrangement of gear coupled manipulators. The approach is based on the idea that the kinematic structure of a gear coupled manipulator can be described by an equivalent open-loop chain (EOLC) and mechanical power transmission lines that drive the EOLC. Conditions to select proper drive train configuration such that manipulators can possess kinematic isotropic property will be presented. Procedures to select gear ratio based on optimum dynamic performance will also be extended from two-degree of freedom (DOF) systems to three-DOF systems. From the determined drive train configuration and gear ratios, location of actuators and details of the mechanical power transmission lines can be decided accordingly. A two-DOF manipulator and a three-DOF wrist are used as illustrative examples.  1997 John Wiley & Sons, Inc.