Research On Three-dimensional Path Planning Of UAV Based On Genetic Algorithm And Sparse A* Algorithm

With the development of automation technology,the level of modern aviation technology has been greatly improved.It also promotes the wide application of Unmanned aerial vehicle(UAV)in the field of military and civilian.The route planning technology of UAV as the key technology of mission planning,has always been a hot research topic.The UAV path planning is to find the optimal or sub optimal trajectory of the UAV from the starting point to the target point while meeting the constraints of the motion.In actual application,as the flying environment is quite complex,and many constraints may appear,the quality of path planning depends both on algorithms and strategies to solve the problems,so how to establish an accurate model of the environment and how to choose an efficient planning algorithm are the key problems of UAV path planning.In this paper,on the basis of genetic algorithm and sparse A* algorithm,the three-dimensional trajectory planning problem is studied.The main research content is as follows:Firstly,the mathematical model of UAV trajectory planning is established,which includes UAV model,constraints and equivalent digital map.This paper focuses on the establishment of three-dimensional mathematical model of UAV's flight environment information,combines the terrain,mountains and threats in the flight area,and establishes the 3D mathematical model including the integrated information of the flight area.Secondly,based on genetic algorithm,the 3D off-line route planning of UAV is studied.In the path planning,genetic algorithms need to be improved to satisfy the task of path planning due to the special gene coding.For this reason,this paper deals with the special operation of the mutation operator,and applies it to the track node to generate a better path.In addition,the fitness function of the algorithm is improved to construct a nonlinear fitness function which is dynamically adjusted according to the evolution iterations.Finally,based on the GA and SAS algorithm,the 3D online path planning of UAV is studied.The improved genetic algorithm combined with sparse A* algorithm is applied to UAV online path planning,the improved genetic algorithm for global path planning of UAV,and the sparse A* algorithm is applied to emergent threat avoidance.Three-dimensional online path planning method proposed in this paper makes full use of the global planning ability of GA and the local planning ability of SAS.The simulation results show that the algorithm is feasible and effective in two different scenarios.