An Inspection Planning Method for Steam Generators with Triangular-Distributed Tubes

With the widespread use of nuclear power, steam generators have been widely used, and their periodic inspection is necessary to ensure reliable operation of steam generators. The planning of the steam generator heat transfer tube inspection robot, i.e., the autonomous operation planning of the robot so that it can inspect the heat transfer tube autonomously and without collision with the environment is a difficult research point for nuclear power plant maintenance robots. Based on the triangular distribution of tube plates, an inspection planning method is proposed in this paper, which includes two parts: task planning and path planning. Based on the distribution of the tube plate and the robot motion, the robot inspection methods are classified into three categories and an evaluation index is proposed for selecting the best planning scheme. Based on the planned robot base inspection positions, an improved A* algorithm is proposed in this paper for robot path planning. To verify the reliability of the proposed algorithm, five sets of experiments are conducted in this paper within a steam generator simulation. The experimental results show that the robot can complete the movement and inspection operations on the tube plate according to the planning results, ensuring full coverage inspection for a given heat transfer tube task. Moreover, after comparing the actual running time of the three planning methods, the robot corresponding to the algorithm proposed in this paper has the shortest running time and the highest working efficiency.