Grid-based RRT∗ for minimum dose walking path-planning in complex radioactive environments

This paper develops an approach to provide path navigation with minimum dose for occupational workers in nuclear facilities to increase personnel safety. An algorithm called GB-RRT∗ is proposed by combining the principle of the rapidly exploring random tree star (RRT∗) with the grid searching strategy. The proposed hybridized algorithm compensates for the weaknesses of RRT∗ with the strengths of the grid search strategy, and is applicable in complex environments with obstacles and narrow areas without relying on pre-designed road networks. Simulation results of the proposed algorithm under three radioactive environments with sparse obstacles, area cluttered with obstacles, and narrow areas are compared with those derived from RRT∗. The results show that the GB-RRT∗ performs better than RRT∗ in both convergence and reliability toward achieving the minimum dose path. Hence, we present a more reliable and efficient for providing the minimum dose path for occupational workers especially in complex radioactive environments with clutter obstacles and narrow areas.