Development of an EAST γ-radiation inspection system based on a quadruped robot

BackgroundThe Experimental Advanced Superconducting Tokamak (EAST) fusion device generates radiation including hard X-rays, γ rays, and 2.45 MeV fusion neutrons during deuterium-deuterium plasma operations, and induced γ rays during shutdown periods.PurposeThis study aims to enhance the radiation monitoring system at EAST by adding a quadruped-robot mobile inspection system, increasing the coverage and flexibility.MethodsA Unitree Go2 quadruped robot equipped with a 3D LiDAR and a γ dosimeter servesas the mobile inspection platform. Based on ROS 2, a Cartographer-based SLAM module and a Navigation2-based autonomous navigation module were developed to realize 2D grid mapping, real-time localization, global path planning and local obstacle avoidance. Meanwhile, a data acquisition program and a local wireless network were deployed to maintain wireless communication between the robot and the host computer, ensuring the returned γ dose-rate data and robot status information.ResultsField tests show reliable hardware–software operation: the mapping error of 0.996%, the average localization error of 4.7 cm, a full inspection loop of the EAST hall of 6 min and 28 s. The linear and angular velocities of the quadruped-robot mobile inspection system is capped at 1.0 m⋅s ⁻¹ and 1.0 rad⋅s ⁻¹, respectively.ConclusionsThis study demonstrates the feasibility of the quadruped robot-based inspection solution for monitoring tasks in the complex radiation environment of fusion devices, providing a novel technical approach and practical reference for future dynamic radiation field monitoring.