Evaluation And Optimazation Of Metroplex Operation

In the 20 th century, the phenomenon of urban agglomeration gradually appeared in the prosperous area. In these areas which are called the urban agglomeration, the transportation network is complex, and there is mutual constraint, mutual linkage between the elements. The highly development of urban agglomeration internal air transportation system causes the increase of density of airports, and a growing interdependence and conditionality between adjacent airports. Multiple airports highly shared airspace, segment and specific fixes become to be the bottleneck of airspace system. The total capacity improvement of the region has been limited. This phenomenon is referred to as metroplex phenomenon. With the metroplex phenomenon, the emergence of more scientific and reasonable planning and construction of the metroplex airspace have become the key of enhancing efficiency of flight traffic management and the airspace management. Therefore, the research presented in this paper focuses on comprehensively introducing the development course of metroplex, and further analyzing the study situation and development trend of national metroplex airports. As such, this paper displays the key method and technology to evaluate and optimize the operation of metroplex, the research contents and achievements mainly include:Firstly, typical metroplex models were built. A scientific comprehensive evaluation system was established to mine the universality rule of the metroplex. The common airspace model of metroplex were summarized in this paper, considering the airports configurations, relative bearing and distance between the airports, runways operation way,typical flow distribution, the sharing way of the point and the flight procedure, and other main factors affecting the operation of many metroplex. 16 kinds of typical metroplex models were established, which were the research objects of this paper.Secondly, the comprehensive evaluation index system of metroplex was established. The characteristics of sharing resources and the dependencies between each were studied, and an index system to evaluate the scheme of metroplex airspace was set up. Interaction indicators include 11 airspace structure coupling and traffic flow running indexes. And running efficiency indexes include 11 airspace utilization and airspace efficiency indexes. The calculation formula of each index and nondimensionalize, invert and(0, 1) interval processing of the index calculation results were also studied in the paper, forming a unified mathematical expression, which provides a data basis of comprehensive evaluation of metroplex scheme.Thirdly, the comprehensive evaluation model of metroplex was established. Adopting multilevel comprehensive evaluation model based on state classification, the assessment target layer, criterion layer and index layer were built, respectively by using analytic hierarchy process and the variation coefficient method to determine the weight of criterion layer and index layer, finally determine the evaluation index threshold, and then divided the interaction level and operational efficiency level into four grades. Assessment model was applied to the 16 typical kinds of airspace scheme of metroplex, to select the optimal scheme, and analyze combining with the airspace structure and the traffic flow operation. Simulation results show that the index set can objectively reflect the coupling of airspace structure and traffic running condition of the evaluation objects. The evaluation model scientifically quantifies the evaluation target level, and supports the construction planning and decision making of metroplex.Forthly, the global multi-objective optimization model of metroplex was established. Considering the configuration of runway, transfer points and overlapping airspace, the objective as to minimize the average delay and the conflict rate and the times of speed governing of flights were defined, and then a global multi-objective optimization model of metroplex based on variable path was established. Four kinds of airspace structure among 16 schemes were selected for simulation, and the global multi-objective optimization results were compared with random first come first service model results. Studies show that the global multi-objective optimization model of metroplex gives consideration to running efficiency, ATC workload, aircraft performance and other multiple constraints. The model reduces the average delay of flights to a certain extent, greatly decreases the workload caused by aircraft conflicts, and optimizes the sharing airspace resources management.Fifthly, a global robust optimization model of metroplex under uncertainty conditions was developed. Based on the objectives of minimize average delay, conflict rate and the times of speed governing of flights to generate the “optimal” decision, and design the absolute, deviation and relatively robust optimization objectives. A 32 transfer fixes airspace structure was selected as the object for simulation validation. The simulation results show that according to the different decision-making preferences, the robust optimization model can evade risk of flight delays as much as possible, simultaneously increase the operation efficiency of the metroplex and reduce the ATC workload.Finally, the innovation points and the main research results of this paper were summarized and the direction of future research was forecasted.