Research On Time-shortest Path Planning Of Multi-waypoint Mission For Unmanned Surface Vehicle

Unmanned Surface Vehicle(USV)path planning technology is the basis to guarantee its execution of searching and mapping,transport inspection and other marine development tasks.The development of this technology is of great significance to improve efficiency and reduce costs.Therefore,the path planning problem involved in the common tasks of USV has been intensively studied in this paper.The proposed fusion algorithm model has achieved the optimal total sailing time of the planned path by reasonably exploiting the environmental perturbations and giving full play to the performance advantages of the USV.The main studies are as follows:(1)In order to effectively simulate the actual working situation of USV,the multi-waypoint traversal path planning problem is fitted to a mathematical model of the Traveling Salesman Problem(TSP)according to its task characteristics,and a mathematical representation of the realistic path planning task is realized.An environmental space was constructed to facilitate simulation operations,and the environmental perturbation and kinematic models in the space were determined,which laying the foundation for the next step of multi-waypoint path planning in tasks such as USV transportation inspection.(2)Considering the influence of environmental disturbances on the speed of USV,and taking the shortest total sailing time as the goal,an ant colony algorithm-based multi-waypoint time-shortest path planning model is established,and the time-optimal waypoint selection problem is studied in the case of environmental disturbances affecting sailing speed.The constructed model is based on the ant colony algorithm and combines the actual situation and task characteristics of the voyage,using dynamic adjustment of parameters,transfer strategy optimization,and pheromone law update to improve the model searching performance.(3)Considering that the USV does not need to stay at the waypoint when performing sweeping and other tasks,it only needs to rely on the on-board equipment to complete the sweeping while traveling,thus the USV is characterized by a continuous steering process.To this end,a virtual steering channel is constructed for the waypoint steering process.Based on the dynamic window method model,the optimal steering trajectory in the channel is determined and the steering time is estimated within the performance of the USV and the on-board equipment.In addition,to make the trajectory planning more reasonable,the transverse swing compensation mechanism is designed and the model is optimized to provide data support for the fusion algorithm to plan the shortest path of steering continuous multi-waypoint time.(4)In view of the fact that the total sailing time of the USV sweep-searching mission contains two parts: steering time and straight sailing time between waypoint,a solution algorithm model based on the fusion of improved ant colony and compensated dynamic window method is designed.Using the compensated dynamic window method to generate the steering elapsed time for each angle and applying an improved ant colony model nested with it,a new time-shortest dynamic planning fusion algorithm model is proposed.With the fusion algorithm calculation,the USV multi-waypoint traversal time shortest path with continuous steering process is obtained.The feasibility and effectiveness of the algorithm are verified in the simulation experiments.It is verified that the proposed fusion algorithm based on improved ant colony and compensated dynamic window can plan a high quality path with the shortest total sailing time traversing multi-waypoint in the environmental model according to the kinematic characteristics of USV.Therefore,the proposed method has practical significance and good application prospects in USV path planning.