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Payload capacity of balanced robotic manipulators

Published online by Cambridge University Press:  17 August 2017

T. G. Lim
Affiliation:
Department of Production Engineering, Korea Advanced Institute of Science and Technology, P.O. Box 150, Cheongryang, Seoul (South Korea)
H. S. Cho
Affiliation:
Department of Production Engineering, Korea Advanced Institute of Science and Technology, P.O. Box 150, Cheongryang, Seoul (South Korea)
W. K. Chung
Affiliation:
Department of Mechanical Engineering, Pohang Institute of Science and Technology, Pohang (South Korea)

Summary

The payload capacity of a conventional robot is usually limited as compared to the mass of the robot body. This is because a payload adds additional gravity loadings to the robot joints resulting in large input joint torques. To reduce the required input joint torques, the authors have proposed a mechanical balancing mechanism. Basically, the mechanism was designed to exactly balance the first three links of an articulated robot by adjusting the positions of counter-balancing masses so as to eliminate the gravity loading terms. Since the input joint torques are greatly reduced by adopting balancing mechanisms, a balanced robot is expected to carry heavier payload and move with higher speed and acceleration. This paper further investigates the possibilities of improving the payload capacity as well as speed and acceleration capabilities. These features were investigated under various operating conditions involving payload, maximum angular velocity, and acceleration period. Based upon the simulation results, the performances of the balanced robot are compared in detail with those of a unbalanced conventional robot.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1990

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