Development of Mechanical Regulator of Physical Human-Robot Interaction to Stabilize the Impedance Control in a Constraint State

Abstract

The purpose of this paper is to develop a mechanical regulator and a robot motion control scheme for a human-robot cooperative task in stiff environment. The proposed mechanical regulator realizes the stable motion of the robot in the stiff environment by regulating dynamical interference between human dynamics and robot dynamics. The proposed mechanical regulator is composed of following components: (i) the motion-detecting system that detects relative positional deflection data between the human motion and the robot motion; (ii) the mechanical load regulating device that regulates an operational load of the robot motion for the human; (iii) the mechanical gravity canceller that reduces a dead load with the mechanical regulator when an operator manipulates the mechanical regulator. In addition, a switching control scheme of impedance parameters is proposed to realize the human-robot cooperative task in the stiff environment. To confirm the effectiveness of the proposed mechanical regulator and the proposed switching control scheme, experiments of the human-robot cooperative task in the constraint state are carried out. The experimental results show that the proposed mechanical regulator and the proposed switching control scheme are effective for the human-robot cooperation in the constraint state.