The path-planning in radioactive environment based on HIOSD-PRM method

Abstract

To ensure the safety of workers in the radioactive environment of nuclear facilities, it is necessary to develop an effective method to plan the walking path with a relatively small dose based on the information of the radiation field. In this paper, a stable and effective path planning method in the complex static radiation field is proposed based on the high-index optimization-based shrinking dimer (HIOSD) method and probabilistic roadmap (PRM) method. In a two-dimensional radiation field, local paths consist of plenty of dimers connecting saddle points to local minima can be dynamically built by the HIOSD method. With these local paths, the PRM algorithm combined with the A* algorithm is applied to optimize the whole walking path from the start point to the goal point based on the dose calculation model. To verify the effectiveness of our method, two application cases in hypothetical radiation fields are shown and we compared the results of the HIOSD-PRM method and the traditional PRM method. The results show that the average cumulative dose of the former in both cases is lower than those of the PRM method and it is worth mentioning that in case 2 with more sources, the HIOSD-PRM method shows very good stability. The built local paths which have much potential can be used multiple times and they can reduce the uncertainty of heuristic algorithms. Overall, this method is suitable for static energy fields with multiple radioactive sources and can reduce the radiation exposure to the workers in the radioactive environment of nuclear facilities.