Research On Unmanned Surface Vehicle Obstacle Avoidance System Based On 3D Lidar

With the rise of intelligent driving,Unmanned Surface Vehicle(USV),as an important marine equipment,is being widely researched and applied in practice.As an important branch in the research of USVs,autonomous obstacle avoidance has always attracted people’s attention.An USV that can realize route planning and obstacle avoidance can effectively solve various problems encountered by USVs on the water,and ensure the successful completion of USV route tasks.In this paper,the obstacle detection method and obstacle avoidance method of USV obstacle avoidance system are studied based on 3D lidar.The main research contents are as follows:Firstly,this paper reviews the research status of obstacle detection methods and obstacle avoidance methods for USVs at home and abroad,and analyzes their advantages and disadvantages.According to the characteristics of the lidar and the motion characteristics of the USV,this paper establishes the lidar plane simulation model and the USV motion mathematical model.Secondly,the method based on grid map is used to analyze the obstacle information detected by lidar.The clustering of obstacles is clustered using density-based and adaptive threshold clustering method of neighbor grid.The method of combining the least convex hull method and the least square method is used to process the clustered data and extract the outline of the obstacle.And the two frames of lidar data are related to determine the status information of the obstacle.Then,an obstacle avoidance path planning method for USV is designed.The operational constraints of the USV in practice is analyzed.The maximum turning angle of the USV is used to analyze the global obstacle avoidance algorithm,and the A~* algorithm is improved.By judging the area where the obstacle is located,and calculating the relative speed of the USV and the obstacle,and according to the maritime rules and constraints,a method of locally avoiding dynamic obstacles is designed to avoid dynamic and static obstacles at close range.The local obstacle avoidance algorithm is combined with the improved A~* algorithm.Finally,an obstacle avoidance system for USV is built,and the route planning and obstacle avoidance experiment of the USV on the water surface are verified in the outdoor environment.