Research on Path Planning Method of Unmanned Ship Under Complex Sea Conditions

In this paper, we propose a path planning method for intelligent unmanned ships, which is one of the hotspots of ship research and development. The path planning of the unmanned ships sailing on the sea is complex and difficult to solve because of the maneuvering characteristics of large inertia and strong time delay as well as the great disturbance induced by the external environment. To navigate the unmanned ship safely in the real complex marine environment, a new path planning method is proposed in this paper. By making use of the electronic chart, we first construct the marine static grid environment model. We further establish the relationship between the marine disturbance and ship maneuverability by calculating the environmental disturbance force of the sea wind, waves and currents on the unmanned ship. The particle swarm optimization algorithm is then applied to plan a safe and feasible global path where the influence of wind, waves and currents are imposed to the path evaluation function. Based on the planned global path, the local path points are then generated with considering the constraints of the environmental interference on the maneuverability. To navigate the unmanned ship safely to the target points, the dynamic window method is further employed for the local search. The method is verified by the simulations that the sailing time and the cost under the complex environment is reduced, which is more in line with the real navigation situation.