Velocity-Level Kinematics of a Continuously Variable Transmission System for Phri

Abstract

New generation robots pave the way for physical human-robot interaction (pHRI) through improvements in control and design techniques. While the former is achieved with the help of a number of sensory information, variable stiffness actuators (VSA) are exploited for the design of these robots to achieve inherent compliance. Recently, continuously variable transmission-based VSA has been developed to be used for pHRI, specifically for haptics. The fundamental characteristic of this new CVT mechanism is that it regulates output position and torque independently via the sphere transmission element. In this study, velocity-level kinematics of this new CVT system is carried out to demonstrate its step-less speed variation feature. Moreover, simulations are conducted in ADAMS and Solidworks software packages at 8 transmission points selected unequally. Results show that the average value of overall ADAMS and Solidworks errors computed with respect to the computed velocity are reported as 1.09%, and 0.53%, respectively.