Robot Arm Constructed with Bi-Articular Muscles : Stiffness Properties of Bi-Articular Muscles and Its Effect

Abstract

In order to develop a robot arm possessing functional characteristics of bi-articular muscles, we performed theoretical simulation analyses of EMG patterns of human movements. In the present studies, the relationship between the force and the displacement and that between the stiffness ellipse at the end point and the stiffnesses of the six main muscles are described. Results obtained in these studies strongly suggest that the existence of the bi-articular muscles could contribute to improvement of compliant properties of the multi-articular extremity, and to independent control of position, force and stiffness at the end point of the extremity, promising smooth, tine and precise movement of the extremity.