Research On Path Planning And Following Control Of Underactuated Unmanned Surface Vehicle

Benefiting from the progress of artificial intelligence and communication technology,modern ships are developing towards the intellectualization and unmanned direction.Unmanned surface vehicles(USVs)will be widely used in military and civil fields.The path planning and following control technology is the premise and basis for the USVs to complete all tasks,and is the focus of current research,which is also the main content of this paper.First of all,in terms of global path planning,considering that the path planned by the traditional A* algorithm is close to the edge of the obstacle,the influence of the obstacles around the node is considered when selecting the node.in terms of local path planning,aiming at the problem that the path planned by the traditional DWA algorithm will bypass the periphery of the obstacle dense area,which makes the path length longer,and is close to the dynamic obstacle,and the dynamic obstacle avoidance effect is not good,the obstacle search angle is proposed,which classifies the static obstacles according to the navigation direction of the USV,so that the USV can pass through the obstacle dense area without collision,and improve search efficiency.The velocity obstacle method is used to select the navigation speed of the USV,and the sub-functions of relative speed and phase difference angle are proposed to enable the USV to avoid dynamic obstacles at a faster speed.A* and DWA algorithms are integrated,and the operation and improvement of the fusion are introduced in detail,and a multi-dynamic obstacle avoidance algorithm is proposed.Thirdly,regarding path following,considering the parameter tuning problem of traditional PID course controller,an improved genetic algorithm is proposed.Finally,in order to achieve more accurate path following control effect,an adaptive PID controller based on real-time tracking error is proposed to deal with time-varying environmental interference,and a speed and course tracking controller is designed.In navigation,considering the influence of drift angle on course tracking,two predictors are used to compensate it.At the same time,on the basis of the traditional LOS algorithm,the adaptive looking forward distance is selected.The looking forward distance can be adjusted adaptively according to the longitudinal path error,so that the USV can quickly approach the desired path while ensuring the smoothness of the actual track.Considering the problem of course tracking in the initial navigation stage,the course angle is preprocessed to avoid the continuous limit output of the yaw moment caused by the instantaneous tracking of a large course angle,which is not conducive to the actual navigation.The effectiveness of the proposed path tracking algorithm is verified by simulation and comparison experiments.