Design and characterization of a novel mechanism of multiple joint stiffness(MMJS)

This article presents the design, implementation and test of a joint mechanical device created to improve the safety and performance of robots interacting physically with human beings. The mechanism consists of a series of linear springs, preloaded and arranged in such a way to take advantage of the benefits of series elastic actuators and to limit the maximum applicable torque. This is a passive mechanism because it does not have a second actuator system on the same joint. However, it involves a joint system of variable stiffness given the three distinct performance phases it has, each one having a different stiffness value, elastic torque-dependent occurring in the joint.