Aircraft Taxi Routes Planning And 3D Simulation For A-SMGCS

With the rapid development of air transport industry, airport surface traffic flow is increasing, the scale and structure of airport become greater and more complex, the impact of rain, fog and other low visibility weather on airport surface operation also raises constantly. Airport surface operation accidents and low efficiency problems are gradually prominent. Therefore, airport has become a bottleneck of the further development of air transport industry. Traditional manual management mode that relying on ATC controllers for airport surface operation has been unable to meet requirements of large airport. To resolve the problem of safety and efficiency of the airport surface operation, ICAO(International Civil Aviation Organization) proposes the concept of A-SMGCS(Advanced Surface Movement Guidance and Control System), which utilizes multiple new surveillance technology and computer automatic control technique to provide automatic management of movements on airport surface. As one of the four basic A-SMGCS functions, taxi routes planning is an critical means for permitting a safe, orderly and efficient movement of any aircraft. Meanwhile, as a large and complex system which directly related to safety, A-SMGCS must accept a large number of three-dimensional simulation tests and certifications before practical operation. And rationality of route planning results can also be intuitively verified through three-dimensional simulation.This dissertation focuses on aircraft taxi routes planning and three-dimensional simulation(including three-dimensional trajectory simulation and three-dimensional surface movement simulation) for A-SMGCS. The main studies of this dissertation are as following.In this dissertation, the status quo, development trend and the latest research results of aircraft taxi routes planning and three-dimensional simulation of A-SMGCS are summarized comprehensively. The relevant research foundation, concept and development history, functional requirements, research status at home and abroad of A-SMGCS are dissertated systematically.The NP-hard problem of aircraft taxi routes planning is studied, and a taxi routes planning method based on free time window is proposed which is used to solve the contradiction between taxi routes planning optimization and computational complexity. Firstly, a taxi resource graph is established to model airport taxi area, which resolves the problem that directed graph model is too simple which cannot depict the operational procedure on airport surface adequately and Petri net model is too complex which increasing computational complexity. Then, any aircraft is appointed a priority according to flight schedule. Aircraft taxi route is planned sequentially according to the order of aircraft priority. Aircraft can only use free time windows of a taxiway to plan taxi route and previous planned taxi routes cannot be destroyed. The difficulty of solving aircraft taxi routes planning problem is reduced by only needed to find a single aircraft taxi route every time. Overall optimization of the taxi route planning is guaranteed because airport surface traffic is balanced through searching free time windows to get taxi routes. Free time window characteristics are analyzed, which point out conditions of reachability between free time windows and none simultaneous resource exchanges. Since it is a complex centralized solution process to establish, maintain and search a free time window graph, a Multi-Agent System(MAS) is designed which make it simplified through the route management Agent, aircraft Agent and resource node Agent collaborate to solve aircraft taxi route planning problem distributively. Finally, a MAS of aircraft taxi routes planning is developed by Anylogic. Simulation results show that the MAS can quickly find free time windows optimal solution. Aircraft average taxiing time decreased significantly compared to preselection fixed-path set algorithm. And the more aircrafts need to be planned, the more average taxi time can be saved.The problem of optimization and adjustment for real-time route plans of aircraft for A-SMGCS is studied. A taxiing route adjustment method based on priorities, is proposed, which is used to solve the contradiction between real-time and optimization. The process of aircrafts visiting an airport road section according to the planned time windows can be interpreted as the priority of aircrafts on a road section. Delayed aircrafts are punished by decreasing the priority to visit road section, which can avoid delay propagation and reduce impact on the optimization of taxi route plans. The strategy merely adjusts the priority of aircraft to visit taxiing road section, and avoids recalculating the time window; therefore it reduces computational complexity and ensures real-time taxi routes adjustment. Then, two kinds of conflicts: head-on conflicts and circular wait conflicts are analyzed. A colored taxiway-oriented Petri net model is proposed which is use to model movements on airport surface. Aircraft taxiing conflicts can be predicted by analyzing state behaviors of special structure such as circuits and cycle chains, when priority is changed. If there is no conflicts occur, the priority can be changed. Otherwise, the priority can not be changed and low-priority aircrafts must wait until delayed high-priority aircraft has passed taxiing road section. Finally, sufficient condition and priority change strategy of aircrafts conflict-free taxiing are proposed. The effectiveness of the adjustment strategy is validated through example simulations. Simulation results demonstrate that the proposed strategy can avoid conflicts in route plans adjustment, and the control rules are simple, effective and suitable for real-time control.Three-dimensional trajectory simulation is studied, and Google Earth is chosen for the simulation platform. Google Earth COM API is use to do embedded secondary development and three-dimensional trajectory is described by KML language. Three-dimensional trajectory is integrated displayed with free terrain data, satellite pictures and aerial pictures from Google Earth. The simulation system can simulate aircraft three-dimensional trajectory anywhere in the world. The development difficulty is simplified and the development cost is reduced because Google Earth is free. To overcome the problem of mouse and keyboard control couldn’t be achieved in the embedded three-dimensional map window because the open interface of COM API is limited, a Windows hook programming technology is proposed which can intercept and process keyboard and mouse messages. With the Windows hook technology, the operation of three-dimensional trajectory simulation system can be controlled by keyboard and mouse. Tests of the simulation system based on ADS-B data source show that the system can simulate three-dimensional aircraft trajectory intuitively and effectively.Three-dimensional surface movement simulation of aircrafts on airport is studied. The simulation system is drove by real-time track data of ADS-B and based on Linux operation system and FilightGear open-source flight simulator. An airport model is built according to Chendgu Shuangliu international airport prototype by modeling of aircrafts, airport layout, terminal, tower and terrain. Because ADS-B track data has no flight attitude data, an algorithm to extract flight attitude from a space vector, which was connected by two pre and post track points, was proposed. Six degrees of freedom(6-DOF) aircraft movement simulation was realized by importing position and attitude data into FlightGear through its multiplayer interface to drive aircraft models. Simulation results show that, the system can simulate surface movement exactly and realistically. The system provides a low cost solution of three-dimensional surface movement simulation for A-SMGCS because it based on free and open source software.