| In recent years, China’s natural disasters, as well as various public safety accidents happen frequently. All kinds of accidents, disasters, public social security and other emergencies harass people from time to time, which have become a major constraint factor affecting our social harmony and stability and economic prosperity and development. Air rescue has the superiority of speed, efficiency and less restricted geography and space and has arised highly attention from the society. With the rapid development of China’s national economy and vigorously promotion of the low-altitude airspace reform, especially the release of low-altitude airspace management and using regulations, low-flying will usher in a new stage of development.How to take a safe, timely and efficient implementation of low-altitude emergency rescue in the low-flying intensive complex environment in the future has become an urgent important topic at the forefront. This paper aims to concentrate on studying rescue flight trajectory planning problem at complex low-altitude flight environment, facing complex low-altitude environment and dense trend. And the studies of the paper are as follows.(1) Studying the comprehensive evaluation problem of complex low-altitude rescue flight affecting factors and building complex low-altitude rescue flight comprehensive evaluation model based on fuzzy comprehensive evaluation method. The main objective of complex low-altitude rescue is the safety, efficiency and timeliness of rescue flight. However, in dense and mixed flight environment featured with the diversity and complexity of the flight number, flight mission, airspace occupied time, aircraft type and other aspects, how to evaluate affecting factors of complex low-altitude rescue flight, assess systematically internal and external environment of flight rescue and fully grasp the overall situation of the rescue flight have important guiding significance to improve flight efficiency and strengthen the rescue protection capability. Therefore, based on a comprehensive analysis of the complex low-altitude rescue flight, this paper analyses all kinds of factors affecting complex low-altitude rescue flight at the complex low-altitude environment when aircraft operations change and builds complex low-altitude rescue flight evaluation indicator system. Then, this paper adopts fuzzy comprehensive evaluation method to establish complex low-altitude rescue flight comprehensive evaluation model and measure the degree of various types of factors affecting complex low-altitude rescue flight, which provide a theoretical basis for complex low-altitude rescue flight trajectory planning.(2) Studying complex low-altitude rescue flight pre-planning problem and building complex low-altitude rescue flight trajectory pre-planning model based on dimensional and three-dimensional grid airspace track.In a complex and diverse mix dense low-altitude flight environment, how to balance security, timeliness, speed in the process of arriving at resue destination is the primary goal of rescue flight trajectory planning. Given the special nature of the complex emergency rescue flying at low altitude, the existing methods are difficult to apply to complex complete flight trajectory at low altitude emergency rescue plan, so this paper studies complex low-altitude rescue flight pre-planning methods based on the analysis of complex low-altitude rescue flight safety impact mechanism, taking multiple criteria such as the safety of the rescue flight, efficient implementation into consideration and compositing geographical environment, spatial characteristics, the security situation, rescue units, the accident site, rescue aircraft performance, flight plans and diverse constraints and other factors. ①This paper studies low-altitude rescue pre-planning research methods based on dimensional grid airspace track.This paper establishes a two-dimensional spatial grid low-altitude rescue track pre-planning model by taking the goal of shortest total rescue time, considering restricted airspace constraints, leg distance, turning points, safety interval. This paper uses ant colony optimization algorithm to unlock the model. ②This paper studies low-altitude rescue pre-planning research methods based on three-dimensional grid airspace track.This paper considers bad weather, complex terrain rescue aircraft performance, low-altitude flight rules and other constraints and establishes complex low-altitude rescue flight trajectory pre-planning model based on three-dimensional grid airspace track. The model adopts a modified A* algorithm to search a single aircraft’s optimal pre-planning flight trajectory and realizes more aircraft conflict-free pre-planning trajectory by rescue aircraft ground waiting strategy and based on rescue task priority avoidance.(3) Studying complex low-altitude rescue flight trajectory dynamic planning problem and building complex low-altitude rescue four-dimensional trajectory dynamic planning model based on Multi-Agent. Taking the feasibility, operability of the trajectory, aircraft performance,dynamic bad weather,this paper proposes real timeflight conflict exploring algorithm,adopts the strategy of adjusting course to resolute conflict, uses direction code to encode the the request trajectory heading. Using genetic algorithm to select, cross, variate and achieves multi-aircraft conflict-free dynamic trajectory planning in the two-dimensional multi-frame. Based on the above multi-criterion and multi-restrained complex low-altitude dynamic changing information, consides time dimensionality based on three-dimensional dynamic trajectory planning and establishes four-dimensional trajectory dynamic planning model based on Multi-Agent. The model uses and improves ant colony optimization algorithm to resolve, and verifies by simulation that in the complex and harsh weather, rescue aircraft can dynamically adjust the optimal trajectory in real time with a minimum of delay and flew crash point, and satisfy the timeliness of the low-altitude rescue requirements. |
PDF Full Text Request