Development of a hyper-redundant multijoint manipulator for maintenance of nuclear reactors

Abstract

A tendon-driven manipulator, the CT Arm, has a specific tendon traction transmission mechanism, in which a pair of tendons for driving a joint is pulled from base actuators via pulleys mounted on the based-side joints. The mechanism makes the most of the coupled drive function of the tendon tractions and thus enables the lightweight manipulator to exhibit enormous payload capability. By this tendon-driven mechanism, a multijoint manipulator with super-redundant degrees of freedom could be realized, which is suitable to the maintenance of nuclear reactors. In this article, we introduce the CT Arm and discuss the possibility of generating a multijoint maintenance manipulator for nuclear reactors, which must have super-redundant degrees of freedom. A position-coordination approach for a hyper-redundant manipulator to carry tools or inspection equipment passing through a hole to a work location in a nuclear reactor is also proposed. Computer simulation has been used to show the validity of the hyper-redundant manipulator and the position-coordination approach for the maintenance of nuclear reactors.