Analysis for Cooperation of Actuators in Pneumatic Musculoskeletal Leg Model with Asymmetric Antagonistic Structure

Abstract

Many researchers have developed musculoskeletal robots with McKibben pneumatic actuator to elucidate the movement mechanism of animals by a constructive approach in previous studies. These robots can realize various dynamic motions by simple control, such as adjustment of the pressure input patterns. However, the pressure input patterns are often determined by trial and error, and it has not been clarified what kind of mechanism an autonomous coordination pattern like animals is generated. In this study, we propose a new control law based on some force feedback to achieve autonomous coordination of antagonistic muscles. The control law is applied to a leg model with asymmetric antagonistic structure, and the capability was analyzed through numerical simulations and experiments with an actual robot. From these results, it is confirmed that the proposed control law can generate cooperations of the antagonistic muscles and realize periodic motion of the leg.