Design progress of an articulated robotic arm for low-payload maintenance tasks in KSTAR

Maintenance of fusion experimental devices like KSTAR is challenging due to harsh conditions such as high vacuum and temperatures. Typically, long downtime is required to cool and reduce radiation levels before possible human access. To address this, we designed an articulated robotic arm to perform low-payload maintenance tasks inside the KSTAR device. This paper presents the design progress of an articulated robotic arm, including system configuration, hardware design, and structural analysis, as part of a stage-wise approach to developing the arm. The arm is connected to the shuttle device and stored in a cask, totaling 11 m and 13 DoF. We conduct a finite element method (FEM) analysis to ensure design reliability and safety under target load conditions. We use the proposed robot system to perform essential maintenance operations for KSTAR, including visual inspection, debris removal, and other simple tasks. Our robot arm system has the potential to reduce maintenance preparation time, minimize radiation exposure to personnel, and contribute to improving the fusion experiment's operational uptime and efficiency.