Development of a digital twin system for snake endoscope manipulator in fusion reactors

Abstract

Tokamak fusion is one of the solutions to the energy crisis. The environment of the vacuum chamber as a reaction site is extreme, so it needs to be observed during the operation period. This paper has developed a digital twin system for the snake endoscope manipulator (SEM) system, designed to observe of the fusion reactor vacuum chamber. The system includes a five-dimensional model of the SEM digital twin and a three-category architecture encompassing perception, data, and interaction. Additionally, a visualization and interaction system based on ROS-Unity has been developed to depict the working conditions of the SEM accurately. A terminal traction-based trajectory tracking control algorithm has been designed, enabling the SEM to maneuver flexibly within the confined space of the vacuum chamber to avoid collisions and prevent additional damage to the vacuum chamber. The system has integrated a Python-ROS-Unity-based algorithm for joint simulation channel development, which has been used for the virtual simulation experiments of SEM to validate the algorithms and collect data. Furthermore, a prototype has been constructed for virtual-to-real mapping experiments. Experiments show the digital twin system is feasible, with low latency, high sync, and stable operation, which verifies the feasibility of the system.