Systematic design of snake arm maintainer in nuclear industry

Abstract

This paper develops a remote handling system with a Snake Arm Maintainer (SAM) as the end effector, which aims to meet the maintenance needs of various narrow working spaces of the Chinese Fusion Engineering Test Reactor (CFETR). The multi-joint snake-arm is designed with the principle of layered drive to realie the angle synchronisation of adjacent joints, which reduces the complexity of the drive control system, and reduces the volume and weight while ensuring a high spatial curvature. The drive box is connected to the Multi-Purpose Overload Robot (CMOR) through a quick-change connector. The worm gear mechanism realies the reverse folding of the SAM and close to the CMOR, enabling access to the narrow vacuum chamber. Two working methods of SAM are designed based on trajectory planning and trajectory tracking. Finally, based on the actual environment of the CFETR vacuum chamber, simulation experiments were carried out on the rationality of the structural design of the SAM and the correctness of the working methods, which verified the feasibility of working in a narrow vacuum chamber.