Research on Three-Dimensional Full Coverage Path Planning Algorithm for Deep-Sea Mining Vehicles

There are many difficulties for deep-sea mining vehicles to accomplish mining tasks autonomously and efficiently, such as insufficient environmental information, low data processing capabilities of deep-sea mining vehicles, and difficult real-time environmental modeling. This paper proposes a three-dimensional full-coverage path planning algorithm for deep-sea mining vehicles. Firstly, the deep-sea environment information of the mining area is collected by an autonomous underwater robot to construct a three-dimensional static map model. According to the geological type data, a three-dimensional grid model is constructed and the passable and impassable areas are divided. Then, the three-dimensional grid map is divided into multiple flat regions based on the gradient information of the region using the flood fill algorithm, and the minimum transition distance between each flat region is calculated using the Floyd algorithm. Next, a heuristic function is established combining grid status, turning factor, and height information for grid transfer. Considering the problem that mining vehicles will enter dead zones inevitably, the virtual endpoint for leaving the dead zone is found by comprehensively utilizing the distance between grids and the plane minimum transition distance in which the grid is located. To guide the mining vehicle to leave the dead zone and ensure the smallest possible repetition rate, the A* algorithm is improved to find the final escape path. Finally, simulation experiments were designed and conducted using Matlab. The results show that the proposed algorithm can ensure a mining coverage rate of 100%, significantly reduce the vertical change of mining vehicles without a significant increase in repetition rate or turning times, reduce energy consumption. The proposed algorithm improves the work efficiency and economic benefits of deep-sea mining vehicles and provides a theoretical basis for underwater path planning of deep-sea mining vehicles.