Velocity Obstacle-based Algorithm Of Collision Avoidance Of River Ferry

Inland river shipping is an important part of China’s transportation system,which attracts more and more people’s attention because of its low pollution,large capacity and low freight.However,with the development of inland waterway shipping,the number of ships began to increase,and the environment of inland waterway is complex.and changeable,resulting in the frequent occurrence of ship collision accidents.Inland river ferries are related to the life and property safety of the people,and they are an important link to meet the living needs and material exchanges of the people on both sides of the river.At present,a total of more than nine thousand ferry across the country,in a watery,is rich in water resource in the province,the ferry is still an important transportation local people on both sides of the back and forth,but our country is still occur every year a cross the zone collision accident,the main reason is the difference in the crew don’t follow the rules and regulations,shipping status,insufficiency of dangerous degree judgment,avoid unreasonable,navigation infl uence factors such as density,due to the ferry passenger and cargo,so caused great casualties and property losses.To sum up,it is of great significance to study the navigation safety of ferries to ensure the life safety of passengers and the navigation safety of ferries.The thesis is mainly as follows:(1)Based on AIS big data,the ferryboat ship field extraction.By meshing the waters around the ferryboat,the grid occupied by other boats at the same time is calculated by interpolation method,and the grid distribution of other boats at each time is superimposed to obtain the grid density map of the ferryboat.In the vicinity of ferries of similar size,the grid density map of such ferries is obtained by the AIS big data,the boundary scatter map of the ship domain is determined by the mean density method,and the ship domain of such ferries is fitted by ellipse based on the least square method.The ship field is consistent with the influence of inland river flow on safe navigation waters(2)Improved speed obstacle method for collision avoidance of inland river vessels.When ships take collision avoidance measures in the ocean,two ships are relatively far away from each other.For inland waterway relatively narrow,ship collision avoidance measures are close characteristics,this paper proposes a thinking of own ship and target ship at the same time the improvement in the field of ship speed method,and gives the two objects will meet at the time of the collision avoidance measures to avoid the traditional speed barrier method to simplify the two ship question of error caused by particle,at the same time this method is suitable for the relative movement between any two objects,has better universality.(3)At the ferries of Nantong section of the Yangtze river,taking "Jiangsu lu du 3007"as ferries and "Guodian 11" as navigable ships,the ship simulation is carried out,and the whole collision avoidance process is analyzed in detail.