Research On Path Planning Of Water-jet Propelled Unmanned Surface Vessel Based On Optimal Energy Consumption

With the rapid development of the world economy,people's demand for energy is increasing day by day.With the depletion of land resources,people gradually shift their perspectives to the sea.The unmanned boat research caters to this need: on the one hand,unmanned surface vessel(USV)play an important role in the development of marine resources as an aquatic intelligent platform,on the other hand,unmanned boats also joined the maritime security and defense work in various countries.Path planning technology is an important part of the realization of unmanned intelligent,The purpose of this paper is to study the path planning of USV with the optimal energy consumption.The research contents of this paper are:1.In order to analyze the energy consumption of USV at sea,firstly,we need to establish a mathematical model of USV,it includes unmanned kinematics and dynamics models.In addition,there is a need to establish the marine environment model and a waterjet model that provides propulsion for USV.Based on the above models,the energy consumption calculation of USV is analyzed.2.First,the S57 standard electronic chart information is extracted and converted into the path planning data format.Establish the environment map model through the visible graph.Then it analyzes the energy consumption calculation form of USV under the interference of environmental forces such as wind and waves.Then,the local heuristic function of traditional ant colony algorithm is modified to reduce its possibility of falling into local optima.Based on this,the interference of wind and wave is added,and the pheromone function is optimized with the goal of optimal energy consumption.The global path planning which takes the best energy consumption as the goal and the global path with the shortest path are compared.3.In view of the dynamic obstacle,this study adopts an improved artificial potential field method for local path planning.First of all,aiming at the problem of local minimum in artificial potential field(APF)method,a method of rotating magnetic field is proposed to improve the gravitational function.Then,the repulsion function is improved to solve the unreachable target of APF.After improving the artificial potential field method,it is combined with the vector field environment to finally form the planning technology of energy saving under time-varying sea conditions.The effectiveness of this method is verified by simulation.4.Establish a two-layers path planning approach.Based on ant colony algorithm,the global path planning based on the best energy consumption is combined with the local path planning,which is based on the artificial potential field method to save energy under time-varying sea conditions,finally the coordinated switching between the two algorithms is realized.Finally,a large number of simulations prove the effectiveness of the proposed algorithm.In this paper,we study the path planning technology of USV with the best energy consumption,which includes the analysis and calculation of the energy consumption of jet propulsion unmanned boats,the global path planning based on ant colony optimization with the best energy consumption,the improvement APF in the time-varying local conditions of the local path planning,and finally the design of a two-layer path planning method to coordinate the global and local planning switch.