TY - GEN
T1 - Nonlinear Spring system for collision safety
AU - Park, Jung Jun
AU - Kim, Hwi Su
AU - Song, Jae Bok
PY - 2009
Y1 - 2009
N2 - Collision safety between humans and robots has, drawn much attention since service robots are increasingly, being used in human environments. A safe robot arm based on, passive compliance can usually provide faster and more reliable, responses for dynamic collision than an active one involving, sensors and actuators. Since both positioning accuracy and, collision safety of the robot arm are equally important, a robot, arm should have very low stiffness when subjected to a collision, force greater than the injury tolerance, but should otherwise, maintain very high stiffness. To implement these requirements, ,a novel safe joint mechanism (SJM-II) which has much smaller, size and lighter weight than the previous model, is proposed in, this research. The SJM-II has the advantage of nonlinear spring, which is achieved using only passive mechanical elements such, as linear springs and a double-slider mechanism. Various, analyses and experiments on static and dynamic collisions show, that stiffness of the SJM-II is kept very high against an external, torque less than the predetermined threshold torque, but, abruptly drops when the input torque exceeds this threshold, ,thereby guaranteeing positioning accuracy and collision safety., Furthermore, a robot arm with two SJM-IIs is verified to, achieve collision safety in 2D space.
AB - Collision safety between humans and robots has, drawn much attention since service robots are increasingly, being used in human environments. A safe robot arm based on, passive compliance can usually provide faster and more reliable, responses for dynamic collision than an active one involving, sensors and actuators. Since both positioning accuracy and, collision safety of the robot arm are equally important, a robot, arm should have very low stiffness when subjected to a collision, force greater than the injury tolerance, but should otherwise, maintain very high stiffness. To implement these requirements, ,a novel safe joint mechanism (SJM-II) which has much smaller, size and lighter weight than the previous model, is proposed in, this research. The SJM-II has the advantage of nonlinear spring, which is achieved using only passive mechanical elements such, as linear springs and a double-slider mechanism. Various, analyses and experiments on static and dynamic collisions show, that stiffness of the SJM-II is kept very high against an external, torque less than the predetermined threshold torque, but, abruptly drops when the input torque exceeds this threshold, ,thereby guaranteeing positioning accuracy and collision safety., Furthermore, a robot arm with two SJM-IIs is verified to, achieve collision safety in 2D space.
UR - http://www.scopus.com/inward/record.url?scp=70350351101&partnerID=8YFLogxK
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U2 - 10.1109/ROBOT.2009.5152268
DO - 10.1109/ROBOT.2009.5152268
M3 - Conference contribution
AN - SCOPUS:70350351101
SN - 9781424427895
T3 - Proceedings - IEEE International Conference on Robotics and Automation
SP - 3371
EP - 3376
BT - 2009 IEEE International Conference on Robotics and Automation, ICRA '09
T2 - 2009 IEEE International Conference on Robotics and Automation, ICRA '09
Y2 - 12 May 2009 through 17 May 2009
ER -