Localized Coverage Planning for a Heat Transfer Tube Inspection Robot

Abstract

The heat transfer tubes of the steam generator are critical components of the nuclear power system and require regular inspection to ensure safety. The SG-Climbot, a quadruped heat transfer tube inspection robot, is equipped with a guiding device capable of simultaneously aligning with and inspecting two heat transfer tubes. Furthermore, The guiding device must execute hundreds of pose configuration transformations to complete a localized coverage inspection, thereby presenting challenges to the robot's efficient autonomous planning. This letter presents a planning framework for the SG-Climbot's localized coverage inspection task. The framework consists of four planning levels: pair planning, position and orientation planning for the guiding device, inspection sequence planning, and time-optimal trajectory planning. A maximum matching algorithm suitable for robotic arms equipped with dual execution devices to perform tasks has been proposed, achieving the optimal pairing of heat transfer tubes and reducing inspection time by over 48 minutes (18.32% improvement). In addition, we analyze the impact of various Traveling Salesman Problem (TSP) solving algorithms on sequence planning issues that require reaching numerous nodes within short operation times, reducing the arm operating time by 33.20 s (6.99% improvement). Finally, the effectiveness of the proposed planning algorithm was validated through simulations and experiments.