Development and Evaluation of Mechanical Regulator of Dynamical Interference in Human-Robot Cooperative Task System

Abstract

This paper presents development and evaluation of a mechanical regulator and a robot motion control scheme for a human-robot cooperative task system. There are contact stability problems that a control system becomes unstable when the robot using impedance control comes into contact with a stiff environment in human-robot interactions. The proposed robot motion control system enables stable contact with the stiff environment by the proposed regulator. The proposed regulator is developed to adjust the dynamical interference between object inherent dynamics and robot dynamics, and it provides dynamics transparency to a human operator in human-robot dynamics cooperation. The regulator is composed of mechanical load adjuster to transmit the human force to the robot and motion measuring system that detects relative positional deviation data between the human arm tip and a tip of the robot. To confirm the stability of the proposed control system, stability analysis simulations and verification experiments using an arm robot are performed. A human-robot cooperative experiment shows that effectiveness of the proposed system for increasing the stability and the dynamics transparency in human-robot physical interactions.