Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-22T02:57:03.875Z Has data issue: false hasContentIssue false

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Osyczka, A., Zajac, J. and Zamorsky, J., “Optimum design of a relief mechanism of industrial robots15th ISIR, Tokyo, Japan 439444 (1985).Google Scholar
2. Imam, I. and Levy, S., “Application of advanced computer-aided engineering tools for kinematic and dynamic analysis of robot systemsAUTOFACT 4, No. 3, 2851 (12, 1982).Google Scholar
3. Arai, T., Nakano, E., Yano, T., Hashimoto, R. and Takeyama, I., “Development of Direct-Drive human-like manipulator15th ISIR, Tokyo, Japan 447454 (1985).Google Scholar
4. Mahalingam, S. and Sharan, A.M., “The optimal balancing of the robotic manipulatorsIEEE Conf. on Robotics and Automation 828835 (04, 1986).Google Scholar
5. Chung, W.K., Cho, H.S., Lee, C.W. and Warnecke, H.J., “Performance of robotic manipulators with an automatic balancing mechanismASME Winter Annual Meeting, New Orleans 111121 (1984).Google Scholar
6. Chung, W.K., Cho, H.S., Chung, M.J. and Kang, Y.K., “On the dynamic characteristics of balanced robotic man ipulatorsJapan-U.S.A. Symposium on Flexible Automation, Osaka, Japan 119126 (07 1986).Google Scholar
7. Chung, W.K. and Cho, H.S., “On the dynamics and control of robotic manipulators with an automatic balancing mechanismProcs. Institution of Mechanical Engineers 201, No. B1, 2534 (1987).Google Scholar
8. Chung, W.K. and Cho, H.S., “Sensitivity analysis of balanced robotic manipulatorsRobotica 6, 5362 (1988).Google Scholar
9. Chung, W.K. and Cho, H.S., “On the dynamic characteris tics of a balanced PUMA-760 robotIEEE Trans. on Industrial Electronics IE 35, No. 2, 222230 (05, 1988).Google Scholar
10. Chung, W.K., On the Dynamic Characteristics and Control of Balanced Robotic Manipulators, Ph.D. Dissertation (Department of Production Engineering, KAIST, Korea, 1987).Google Scholar
11. Lim, T.G., Cho, H.S. and Chung, W.K., “A parameter identification method for robot dynamic models using a balancing mechanism” Robotica (to appear).Google Scholar
12. Moon, J.I., A Study on Dynamic Parameter Identification of a PUMA-760 Robot, M.S. Thesis (Department of Production Engineering, KAIST, Korea, 1986).Google Scholar
13. Wang, L.T. and Ravani, B., “Dynamic load carrying capacity of mechanical manipulators-Part I: Problem formulationTrans. ASME J. of Dyn. Sys., Meas., and Cont. 110, 4652 (03, 1988).Google Scholar
14. Lim, T.G., On Dynamic Parameter Identification of a PUMA-760 Robot using a Balancing Mechanism, M.S. Thesis (Department of Production Engineering, KAIST, Korea, 1987).Google Scholar