Design and qualification tests of a robotic joint module for tokamak in-vessel manipulator use

Abstract

Purpose This paper aims to present the design and a prototype experiment of a robotic joint module for tokamak in-vessel manipulator-related research; the results will promote the adaptation of current in-vessel inspection manipulator to achieve full tokamak in-vessel environment compatibility. Design/methodology/approach A flexible metallic bellow-enclosed working chamber is used to protect the main servo drive components, the active cooling method for high temperature protection and the servo control structure simplification for high radiation endurance. A joint module prototype is manufactured and tested under a similar in-vessel environmental condition for extreme condition protection validation and basic servo control ability evaluation. Findings The joint module prototype successfully survived the similar in-vessel environment tests and proved good mobility via closed-loop servo control. A conceptual design of a serial linkage manipulator with joint module structure is proposed for future in-vessel inspection manipulator development. Originality/value The proposed joint module uses common industrial servo components to achieve its full extreme in-vessel environment compatibility. Different from traditional metallic bellow application in a vacuum environment to produce a linear movement result, the proposed joint module aims to achieve rotating movement directly from the metallic bellow structure, thereby reducing the joint structure space requirement, simplifying the vacuum environment movement transmission structure and increasing the vacuum environment compatibility degree.

Design and experimental tests of an active cooling system for a kind of in-vessel inspection manipulator

“…An active circulating cooling system was implemented around a single servo motor and partial small arm structure to achieve working ability in high temperature environment (100°C) (Yuan et al , 2015; Chen et al , 2016). A standalone robotic joint module was developed to explore the full in-vessel environment (100°Chigh temperature, 1 × 10 −5 Pa high vacuum, 2,000 Gy/h high radiation) adaptability (Du et al , 2017; Du et al , 2018). Based on these preliminary works, the in-vessel extreme environment adaptation for the current manipulator prototype was planned to be carried out step by step, and the current stage of work will focus on the high temperature environment adaptability on the whole manipulator scale.…”