Ship Path Planning For Restricted Areas Under The Influence Of Marine Meteorological Environment

In recent years,international trade has developed rapidly,and the shipping industry's transportation volume has become larger and larger.With the gradual attention of the public to the marine environment and the intensification of competition among shipping companies,the requirements for the safety and economics of sailing have become increasingly high.The restricted area is a high-risk area in the course of ship navigation.According to the impact on the navigation of the ship,there are mainly two kinds of areas in the restricted area.The first is the non-navigable area,and the ship cannot sail at the boundary or inside of such area.The second is the speed limit area.And the ship can sail in such area,however,it should be lower than the prescribed speed to ensure the safety of the ship.In the course of route planning,this paper takes the marine meteorological environment factors into consideration,and takes the ship's safety to avoid the non-navigable area as the premise,and takes the shortest sailing time as the goal,and builds a route planning model in the restricted area.When considering the marine meteorological environment,the effect of current on ship's speed is analyzed by a vector synthesis model,and the effect of wind and waves on ship's speed is analyzed by a fitted model.Then,according to the model,any the sailing distance of two points can be converted into sailing time.When solving the problem of route planning in the restricted area that does not include the speed limit area,based on the establishment of the environmental model,firstly use the MAKLINK diagram to construct a network connectivity map from the start point to the end point.Then use the established model to calculate sailing time of the path in the connectivity map.Dijkstra algorithm is used to solve the initial optimized route.Finally,the improved particle swarm algorithm is used to search near the inflection point of the initial optimized route,and finally the optimal route is obtained.Improved particle swarm optimization optimizes shorter sailing time and better smoothness.When solving the problem of route planning in a restricted area that includes speed limit area,firstly,the speed limit area is not considered,and it is solved according to the route planning algorithm of the restricted area without considering the speed limit area.If the planned route does not pass the speed limit area,the route is the optimal route.Otherwise,optimize the segment through the speed limit area to get the best route.Finally,the effectiveness of the algorithm in this paper is verified through an example.The results show that considering the impact of the marine meteorological environment than the planned route without considering the impact of the marine meteorological environment is more realistic,with shorter sailing time and better smoothness.The route planning algorithm with or without the speed limit area can improve safety and economy of the route for ships passing through the restricted area.