A proposal idea for a non-active variable stiffness Spring-Clutch

This paper discusses a variable stiffness Spring-Clutch. A human and robot work together frequently, a lot of devices have been developed to guarantee the safety between human and robot. A safe joint device may possess a function of controlling stiffness of joint or disengaging an actuator unit from the joint of manipulator when large torque is exerted at the joint than predetermined threshold torque. In this paper, the Spring-Clutch (SC) and active variable stiffness Spring-Clutch (AVSC) are briefly introduced. Limitations of AVSC are discussed in the view points of practical implementation and dynamic responses. To satisfy the dynamic specifications an idea of non-active VSC is introduced.