Research On Route Diversion Based On Conflict Avoidance Under Bad Weather

Thunderstorms are the most dangerous weather.Thunderstorm coverage area will bring great harm to flight safety.In order to prevent aircraft from crossing the area of thunderstorms and ensure a flight security,ground waiting is a common method of avoiding thunderstorms.However,that will cause a large number of aircraft to be unable to departure or arrival and cause huge economic losses to the airlines and the society.The implementation of route diversion is an effective way to deal with this problem.This paper studies designing the diversion route method for a single aircraft that fly around a thunderstorm and the diversion route planning for multiple aircraft collision avoidance.The paper takes the Graham algorithm and the ant colony algorithm improved by Artificial Potential Field as the theory to solve the above problems from the following aspects.(1)Based on the analysis of the causes and processes of thunderstorms,the paper describes the hazards associated with flying such as ice accretion,turbulence,and wind shear that occur with thunderstorms.According to the distribution of thunderstorms in the airspace,thunderstorms are divided into blocks,bands,and scattered spots.Through the above analysis,the static danger zone is demarcated by the Graham algorithm,and several methods of dynamic risk zone developed based on the static danger zone are analyzed.In this paper,spatial information coding is used to construct an airspace information matrix once to describe the thunderstorm danger zone.(2)Describes the related definitions of route rerouting and the constraints of designing route.Building a collision-free rerouting model based on flight planning routes for single aircraft and multiple collision-free aircraft.A comprehensive analysis of ant colony algorithm and artificial potential field method,by combining the advantages of the two algorithms in the path planning,using artificial potential field method to improve the information heuristic factors of ant colony algorithm.The improved ant colony algorithm is used to research new route to deviate the different types of dangerous areas.The results show that the algorithm can achieve the purpose of diversion.(3)Introduce the definition and method of conflict detection and use the velocity model and the geometric deterministic algorithm to determine whether there is conflict between the two aircraft at the same altitude and in the same track.The evasive conflict diversion model based on flight planning route was proposed for aircraft diversion between the front and rear collisions.Then the ant colony algorithm with improved artificial potential field and the diversion model for avoiding collisions were used to search for the path of avoidance conflict.Through the simulation and verification of different types of danger zones,it is proved that this algorithm can realize the rerouting path planning around the flying thunderstorm danger zone.