Experimental Investigation of Trajectory Control for Regions of the Human Body Using a Parallel Wire-driven Mechanism and Iterative Learning Control

Abstract

We are investigating the performance of trajectory control when passive motion is given to a region of the human body. Such passive motion given by trajectory control using a robotics device has been applied to motion analysis of the human body. In this paper, we focus on a parallel wire-driven system that utilizes light flexible wires instead of heavy rigid links, which characteristically has many advantages such as safety, structural transparency, large motion area, ease of maintenance and expandability as compared with other systems. Reeling wires by actuators, this system can control the length of wires or tension. In regards to trajectory control, iterative learning control is one of the most useful methods for this case, because the scheme can easily achieve trajectory control with a high degree of accuracy even if system-dynamics is unknown and fluctuate. We deal with the passive motion of a human arm in a vertical plane using the parallel wire-driven mechanism and iterative learning control. The purpose of this study is to evaluate the performance of the trajectory control quantitatively by measuring EMGs and R—R intervals.