The Coupled Tendon-driven System for Musculoskeletal Elbow Joints

Abstract

In this paper, the control method for a musculoskeletal mechanism simulating a human forearm is discussed. The human muscular system which is basically the multi-feedback system, serves for skillful human motions. The joint's compliance is controllable to regulate the spinal reflex feedback gains of muscle's length and tension. Furthermore, the cooperation of biarticular and uniarticular muscles improve the manipulation ability and the efficiency of energy. Because the tendon-driven system is similar to the human muscular system, we can take these superior characteristics of the human muscular system into our manipulator. Our manipulator has a similar mechanism to the human forearm and has 2 D.O.F motions (flexion, extension and external, internal rotation) by three contending tendon-driven systems. The control method for this manipulator is designed by imitating the human muscular control system based on spinal reflexes. In the controlled system, each wire compliance is adjustable to change the feedback gains of wire length and tension, and the manipulator compliance under the position control can be controlled by the regulation of the wire compliance without measuring the outer force.