Interference-Drive of a 3DOF Joint Based on the Cable-Controlled Mechanism

Abstract

This paper discusses a new mechanism for a 3DOF joint which is constructed by a cable-controlled mechanism and an interference drive system. This is equivalent to a parallel mechanism having flexible links. However, it is difficult to drive the mechanism by an ordinary procedure because it has a redundancy of drive-cables given the DOF of the joint. Therefore, in this paper, a transform equation is formulated between the drive system and the joint system, and an effective algorithm is proposed for computation on the tensions of cables based on vector analysis. An experiment for dynamical tracking control of the mechanism as an imaginary walking leg is tried using a computed torque technique. As the result, it is concluded that the cable-controlled mechanism is effective for a 3DOF joint.