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A Passive Gravity-Compensation System for Articulated Robots

수직다관절 로봇의 중력보상장치 개발 및 성능 분석

  • Published : 2000.02.01

Abstract

This paper presents a new passive gravity -compensating system for articulated robot manipulators. The system, which consists of linear zero- free -length springs, achieves exact counterbalancing o f the gravitational loads throughout the entire range of the manipulator workspace, A basic concept is to design springs such that the total potential energy of the system including the manipulator and the springs should be maintained constant. A prototype has been developed for a direct-drive five-bar manipulator and its performances have been investigated. Results show that the gravity-induced motor torques have been reduced to less than 5% of those of uncompensated robots. Also, the gravity-compensating system simplifies the position control algorithm while maintaining the trajectory-tracking errors in a satisfactory level. In conclusion, the proposed system efficiently improves the manipulator performances by reducing the driving motor size and the energy consumption as well as by simplifying the control systems.

Keywords

Articulated Robot;Gravity Compensation;Spring Balance;Zero-Free-Length Spring;Motor Torque;Energy Consumption

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