Simulation of Power-Assisted Upper-Arm Reaching Movements based on PD Control with Gravity Compensation

Abstract

We examined a two-link upper-arm reaching movement of humans based on power-assist system in computer simulation. The power-assist motors were attached at the shoulder and the elbow joints, and the motor torques based on PD control and gravity compensation were added to the joint torques of the musculoskeletal system. We assumed an optimality principle to compute the adapted movement of humans for a power assist system and compared the performances of the power-assisted movements. The results show that the computer simulation can reproduce the reduction of the electrical activities of the muscles.