Research On Lateral Minimal Separation Of Parallel Air Routes Based On Traffic Flow Simulation

The air traffic on Beijing-Shanghai,Beijing-Guangzhou and other major ATS routes is closed to or even over their designed capacity in some periods because of keeping rising of Chinese civil aviation traffic these years.Tactical measures,such as long-distance detour,mid and low altitude cruise and flow control,have been taken to avoid the congestion of these major routes.But these means actually only have limited effectiveness and bring economic problems such as high fuel consumption to airlines.The design of parallel routes is an effective method to alleviate the shortage of airspace resources and improve the capacity of air routes from the perspective of airspace planning.Besides,it can maximize the use of existing navigation infrastructures and reduce the distance of detouring,which is very economical.Center-line spacing,the lateral minimum distance of parallel routes,is the basic parameter that needs to be determined for parallel routes establishment.New air navigation technologies,especially PBN and other technologies,have enabled the situation of a smaller separation could meet required safety level.Therefore,the assessment of lateral minimum separation provides the lowest safety configuration reference for parallel routes planning.The assessment of lateral separation can not be cut from the collision risk model in the traditional flight separation theory system.At the same time,it is necessary to consider the influence of various random factors and the relationship between the adjacent aircraft during the parallel tracks operation.Therefore,this paper divides the assessment of lateral separation into two parts: static collision risk model and dynamic traffic flow simulation.In order to establish a static collision risk model that is more suitable for lateral separation assessment of parallel routes,the applicability analysis of Reich model,stochastic differential equation model and Event model in the classic collision risk model system is carried out.In doing so,the Event model is selected for model improvement with a heteromorphic collision box.Combined with ADS-B data for overlapping segment identification,the simplified ANP calculation method is proposed and used to obtain the lateral separation loss rate required for the assessment of the improved Event model.After selecting other required parameters,the static separation assessment is performed and obtained the result value of 7.5 km.Based on analysis of parallel routes operation characteristics during aircraft operation,such as piloting and navigation characteristics,human characteristics and environmental characteristics,a multi-random factors' layered model is established to generate the aircraft lateral positionerrors.After sampling test,the model is verified that it could effectively reflect the RNP1 route specification,the human factors between controllers and pilots,and the lateral error distribution law of the environmental factors such as crosswinds and gusts in the Beijing-Shanghai area route.Based on the cell transmission theory,a pseudo-two-dimensional cellular automaton model with simulation rules and separation maintaining procedure is proposed in this paper for parallel routes traffic flow simulation.After the model validity test,the static separation value is input as the initial value into the cellular automaton model for air traffic flow simulation.And finally,the 10 km lateral minimum separation value for RNP1 is obtained,which could provide a basis for close distance parallel routes designing to the airspace planning researchers.