Direct-drive Master-Manipulator: Design Principles and Characteristics

Abstract

This paper proposes the following design principles for direct-drive master manipulator: 1) All joints are directly driven by torque motors. 2) All links are self-balanced, and minimization of inertia around the first axis is considered. 3) The fourth, fifth and sixth axes are intersecting in one point.
A master-manipulator realized based on these principles has shown the following characteristics: 1) No backlash can be observed. Positional measurement errors are within 1 mm in the meaning of standard deviation. 2) Stationary friction torques are 0.17 N, 0.039 N and 0.059 N in x, y and z direction respectively. 3) Linearity of generated force is satisfactory and deviation is about 0.03 N.