Research On Real-time Path Planning And Formation Control Of Unmanned Surface Vehicle Formation

Unmanned Surface Vehicle(USV),as a water platform with autonomous navigation and operation,has the characteristics of small size,high speed and strong maneuverability,and it also undertakes more and more important tasks in the military and civilian fields.Path planning is one of the important research contents on unmanned surface vehicle,and it is also the key technology for unmanned surface vehicle to realize intelligent navigation.Compared with a single unmanned surface vehicle,the use of multiple USV to form a team to cooperate can expand its mission area,improve the robustness of the entire system,and ensure that the scheduled tasks can be successfully completed.In this context,this paper studies related technologies,and designs USV formation path planning and autonomous obstacle avoidance algorithms suitable for dynamic environments.The main work of the paper is as follows:(1)Design a global path planning algorithm based on IRRT*,which has low sampling efficiency and no tendency towards the goal of the RRT* algorithm.An improved IRRT*algorithm is designed.Based on the original RRT* algorithm,the improved IRRT* algorithm can quickly generate feasible paths,while effectively reducing the sampling area and promoting the growth of the search tree toward the target.The search efficiency of the algorithm.Then,the B-spline function is applied to the path smoothing process to improve the problem that the original path turns too large,make it more in line with the kinematic characteristics of the surface USV,and improve the efficiency and performance of the global path planning algorithm of the USV.(2)Based on the traditional dynamic window method,a local obstacle avoidance algorithm influenced by wind and waves is proposed.Combined with the actual operating environment of the unmanned surface vehicle,the influence of the flow field is embodied as an evaluation function to participate in the update of the dynamic window method,so as to realize the path planning of USV in the presence of a flow field,and verify its flow in the flow field through simulation.Effectiveness of path planning under field influence.(3)In order to realize the dynamic obstacle avoidance of USV in complex environments,a hybrid path planning algorithm based on IRRT* and improved DWA is proposed.The algorithm is simulated and compared with the DWA algorithm to verify the effectiveness of the hybrid algorithm..Data collection is carried out by USV equipped with a radar and an integrated navigation system,and a semi-physical simulation experiment is carried out.It has been verified that this algorithm can better avoid dynamic and static obstacles,and at the same time navigate along the reference path as much as possible,and successfully plan a complete path.(4)For the path planning problem of USV formations,a behavior-based method combined with virtual leader is proposed,and the center of mass of the unmanned surface vehicle formation is used as the virtual leader,so as to avoid the failure of the real navigator and the loss of control of the formation.Condition.By setting the basic behavior of USV in the formation,they can have autonomous obstacle avoidance ability on the basis of maintaining the formation.The path planning and obstacle avoidance ability of the USV formation is verified by simulation experiments,and it is proved that the method can maintain a certain formation and has a good obstacle avoidance ability when the number of formation members is large.