Extraction and implementation of muscle synergies in hand-force control

Abstract

The need of solving the problem of multi-degrees of-freedom in motor control is increasing as human-like robots become more popular these days. Muscle synergies hypothesis is a prominent suggestion for this problem. In this paper, we investigated the muscle synergies extracted from human subjects in a producing-force task to explore the mechanism of the human's skillful hand-movement at producing force while manipulating objects. We observed a high correlation estimation of the muscle synergies with the hand force, and derived a role division of muscle synergies in generating the hand force as well. These results give an optimal but simple way to control robots so as to make the robots' movement as skillful as human's. To verify this idea, we proposed "synergy based control" method using the characteristics of human's muscle synergies observed, and tested it on a pneumatic-driven arm robot whose structure assumes the human arm's. The program is in its first stage to control the robot.