A Wall-Mounted Robot Arm Equipped with a 4-DOF Yaw-Pitch-Yaw-Pitch Counterbalance Mechanism

Jae Kyung Min, Do Won Kim, Jae Bok Song

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Because industrial robots are relatively heavy, most of motor torque are used to support the weight of a robot. Consequently, high-capacity motors and speed reducers are needed, resulting in a low energy efficiency and an increase in the manufacturing cost. To deal with this problem, a variety of spring-based counterbalance mechanisms (CBM) have been developed to mechanically compensate for the gravitational torque caused by the robot weight and payload. However, conventional CBMs are limited to pitch joints whose axis of rotation is horizontal to the ground and it is difficult to apply them to robot arms with different joint configurations, such as humanoid robot arms. In this study, we propose a CBM with a passive yaw-pitch structure consisting of a spring and wire. Through geometrical analysis and experiments, we demonstrate that the proposed CBM can effectively compensate for the gravitational torque due to robot weight and payload.

Original languageEnglish
Article number9006847
Pages (from-to)3773-3779
Number of pages7
JournalIEEE Robotics and Automation Letters
Issue number3
Publication statusPublished - 2020 Jul

Bibliographical note

Funding Information:
Manuscript received September 10, 2019; accepted January 19, 2020. Date of publication February 21, 2020; date of current version April 6, 2020. This letter was recommended for publication by Associate Editor S. Briot and Editor P. Rocco upon evaluation of the reviewers’ comments. This work was supported by MOTIE under the Industrial Foundation Technology Development Program supervised by KEIT (20005032). (Corresponding author: Jae-Bok Song.) The authors are with the School of Mechanical Eng., Korea University, Seoul 02841, Korea (e-mail: mjk90123@korea.ac.kr; ehdnjs119@korea.ac.kr; jbsong@korea.ac.kr). Digital Object Identifier 10.1109/LRA.2020.2975731

Publisher Copyright:
© 2016 IEEE.


  • Manipulators
  • Springs

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Biomedical Engineering
  • Human-Computer Interaction
  • Mechanical Engineering
  • Computer Vision and Pattern Recognition
  • Computer Science Applications
  • Control and Optimization
  • Artificial Intelligence


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