Safe joint mechanism based on passive compliance for collision safety

Jung Jun Park, Jae Bok Song, Hong Seok Kim

Research output: Chapter in Book/Report/Conference proceedingConference contribution

23 Citations (Scopus)


A safe robot arm can be achieved by either a passive or active compliance system. A passive compliance system composed of purely mechanical elements often provide faster and more reliable responses for dynamic collision than an active one involving sensors and actuators. Since both positioning accuracy and collision safety are important, a robot arm should exhibit very low stiffness when subjected to a collision force greater than the one causing human injury, but maintain very high stiffness otherwise. To implement these requirements, a novel safe joint mechanism (SJM), which consists of linear springs and a slider-crank mechanism, is proposed in this research. The SJM has the advantages of variable stiffness which can be achieved only by passive mechanical elements. Various experiments of static and dynamic collisions showed the high stiffness of the SJM against an external force of less than the critical impact force, but an abrupt drop in the stiffness when the external force exceeds the critical force, thus guaranteeing collision safety. Furthermore, the critical impact force can be set to any value depending on the application.

Original languageEnglish
Title of host publicationRecent Progress in Robotics
Subtitle of host publicationViable Robotic Service to Human
EditorsSukhan Lee, Il Hong Suh, Kim Mun Sang
Number of pages13
Publication statusPublished - 2008

Publication series

NameLecture Notes in Control and Information Sciences
ISSN (Print)0170-8643

Bibliographical note

Funding Information:
Acknowledgements. This research was supported by the Personal Robot Development Project funded by the Ministry of Commerce, Industry and Energy of Korea. fdgdfgfdgfd

ASJC Scopus subject areas

  • Library and Information Sciences


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