Urban air traffic aircraft spatial-temporal distribution evaluation system and method based on spatial density

Abstract

The invention discloses an urban air traffic aircraft spatial and temporal distribution evaluation system and method based on spatial density. The system comprises an airspace gridding module, an air route discretization module and a spatial distribution evaluation module. The airspace gridding module is used for carrying out discrete operation on a to-be-evaluated airspace to obtain a plurality of space units; the route discretization module is used for carrying out discretization operation on an aircraft route to obtain route discrete points of the route in the airspace to be evaluated; and the spatial distribution evaluation module performs spatial distribution evaluation based on the plurality of spatial units and the flight route discrete points to obtain flight spatial density. According to the method, quantitative evaluation of the space-time distribution rule of the aircraft in the UAM dense flight scene is realized in combination with a space density algorithm, and a foundation is laid for evaluation and optimization of operation safety of a whole operation system.

Description

Technical Field

[0001] The present invention belongs to the technical field of air traffic, and in particular relates to a system and method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density. Background Art

[0002] The rapid development of urban air mobility (UAM) is an irresistible trend, and electric vertical take-off and landing (eVTOL) is the mainstream solution for the future UAM market. UAM is a safe and efficient manned / unmanned air traffic system for passenger or freight transportation in cities. The system focuses on short-distance transportation (3-100km) within or between cities, and provides support for ultra-low altitude below 100 meters or low-altitude regional flight traffic of 100-1000 meters. According to authoritative predictions, low-altitude airspace will generate huge social demand in the future. Among them, eVTOL aircraft with autonomous driving capabilities use batteries as energy, have less noise during flight, safer and more reliable operating systems, do not rely on runways and are smaller in size, have greater freedom in flying and parking, and are more conducive to transportation operations within cities. They are the mainstream solution for the future UAM market.

[0003] However, unlike traditional aviation, low-altitude intensive flight operation scenarios will present traffic flow characteristics with large volume, high density, and diverse flight performance and control methods. This will lead to a surge in flight conflict events, and it will be impossible to rely on controllers to avoid collision events. The operational risks caused by flight conflicts cannot be ignored, and the temporal and spatial distribution of aircraft will become one of the important considerations for risk assessment of operational scenarios. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0005] An urban air traffic aircraft spatiotemporal distribution assessment system based on spatial density, comprising: an airspace gridding module, a route discretization module and a spatial distribution assessment module;

[0006] The airspace gridding module is used to discretize the airspace to be evaluated to obtain a number of space units;

[0007] The route discretization module is used to discretize the aircraft route to obtain route discrete points within the airspace to be evaluated;

[0008] The spatial distribution evaluation module performs spatial distribution evaluation based on a number of the spatial units and the route discrete points to obtain flight spatial density.

[0009] Preferably, the spatial gridding module includes: a spatial unit characterization submodule and a spatial unit volume calculation submodule;

[0010] The spatial unit characterization submodule is used to divide the airspace to be evaluated into a plurality of spatial units and characterize the spatial units:

[0011] Cell(i,j,k)=λ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+i ]

[0012] λ i =λ min +(i-1)×Δλ,i=1,2,...,Nλ

[0013] θ j =θ min +(j–1)×Δθ,j=1,2,...,N θ

[0014] H k =H min +(k-1)×ΔH,k=1,2,...,N H

[0015] Among them, Cell(i, j, k) represents the spatial unit, λ represents longitude, θ represents latitude, H represents height, λ represents the min represents the lower limit of the longitude of the airspace to be evaluated, θ min Indicates the lower latitude limit of the airspace to be evaluated, H min represents the lower limit of the airspace height to be evaluated, Δλ represents the discrete interval step size of longitude, Δθ represents the discrete interval step size of latitude, ΔH represents the discrete interval step size of height, and N λ A discrete number representing longitude, N θ A discrete number representing longitude, N H Represents the discrete number of longitude, i, j, k represent natural numbers;

[0016] The space unit volume calculation submodule calculates the volume of each of the unit spaces based on the representation:

[0017]

[0018] Among them, dV(i, j, k) represents the volume of the unit space, r represents the height integration factor, represents the geographic latitude integration factor, and γ represents the geographic longitude integration factor.

[0019] Preferably, the route discretization module includes: a route length calculation submodule and a discrete point representation submodule;

[0020] The route length calculation submodule is used to obtain the starting longitude λ of flight ε up 、Starting point latitude θ up , the end point longitude λ down , end point latitude θ down and the average flight altitude H ε , and calculate the route length:

[0021] D ε =(Re+H ε )×arccos(sinθ up sinθ down +cosθ up cosθ down cos(λ up -λ down ))

[0022] Among them, D ε represents the length of the route, Re represents the radius of the earth;

[0023] The discrete point representation submodule is used to obtain the discrete time interval dt of the route, and obtain the representation of the discrete points of the route based on the route length:

[0024]

[0025] H ε_σ H ε

[0026] σ=1,2,...n ε

[0027]

[0028] Among them, λ ε_σ Represents the geographic longitude of discrete points on the route, θ ε_σ Indicates the geographical latitude of discrete points on the route, H ε_σ represents the altitude of the discrete point on the route, σ represents the sequence number of the discrete point on the route, and n ε represents the total number of discrete points of flight ε on the route, v ε Indicates the aircraft's operating speed;

[0029] For a discrete point σ, if:

[0030] λε_σ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,Hk+1 ]

[0031] Then the discrete point σ belongs to the spatial unit Cell(i, j, k). The total number of discrete points of route ε in the spatial unit Cell(i, j, k) is n(ε|Cell(i, j, k)).

[0032] Preferably, the spatial distribution assessment module includes: a single flight airspace density assessment submodule and a total airspace density assessment submodule;

[0033] The single flight airspace density assessment submodule is used to obtain the total number of discrete points n(ε|Cell(i, j, k)) in the spatial unit and calculate the airspace density of the flight ε:

[0034]

[0035] in, represents the airspace density of flight ε during the evaluation period, ΔT represents the evaluation period, and MC represents the number of flight ε during the evaluation period;

[0036] The total airspace density evaluation submodule calculates all N based on the airspace density of the flight ε. line The total flight space density of the flight during the evaluation period is:

[0037]

[0038] in, N line The total spatial density of said flights during the evaluation period.

[0039] The present invention also provides a method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density, the evaluation method being applied to any of the above-mentioned evaluation systems, comprising the following steps:

[0040] Discretize the airspace to be evaluated to obtain several spatial units;

[0041] Performing discretization operation on the aircraft route to obtain discrete route points of the route within the airspace to be evaluated;

[0042] A spatial distribution evaluation is performed based on the plurality of spatial units and the discrete points of the routes to obtain the flight spatial density.

[0043] Preferably, the method for obtaining the plurality of said spatial units comprises:

[0044] The airspace to be evaluated is divided into a plurality of space units, and the space units are characterized:

[0045] Cell(i,j,k)=λ∈[λi ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+1 ]

[0046] λ i =λ min +(i-1)×Δλ,i=1,2,...,N λ

[0047] θ j =θ min +(j-1)×Δθ,j=1,2,…,N θ

[0048] H k =H min +(k-1)×ΔH,k=1,2,...,N H

[0049] Among them, Cell(i, j, k) represents the spatial unit, λ represents longitude, θ represents latitude, H represents height, λ represents the min represents the lower limit of the longitude of the airspace to be evaluated, θ min Indicates the lower latitude limit of the airspace to be evaluated, H min represents the lower limit of the airspace height to be evaluated, Δλ represents the discrete interval step size of longitude, Δθ represents the discrete interval step size of latitude, ΔH represents the discrete interval step size of height, and N λ A discrete number representing longitude, N θ A discrete number representing longitude, N H Represents the discrete number of longitude, i, j, k represent natural numbers;

[0050] The volume of each of the unit spaces is calculated based on the representation:

[0051]

[0052] Among them, dV(i, j, k) represents the volume of the unit space, r represents the height integration factor, represents the geographic latitude integration factor, and γ represents the geographic longitude integration factor.

[0053] Preferably, the method for obtaining the discrete points of the route includes:

[0054] Get the starting longitude λ of flight ε up 、Starting point latitude θ up , the end point longitude λ down , end point latitude θ down and the average flight altitude H ε , and calculate the route length:

[0055] D ε =(Re+H ε )×arccos(sinθ up sinθ down +cosθ up cosθ down cos(λ up -λ down ))

[0056] Among them, D ε represents the length of the route, Re represents the radius of the earth;

[0057] Obtain the discrete time interval dt of the route, and obtain the representation of the discrete points of the route based on the length of the route:

[0058]

[0059] H ε_σ =H ε

[0060] σ=1,2,...n ε

[0061]

[0062] Among them, λ ε_σ Represents the geographic longitude of discrete points on the route, θ ε_σ Indicates the geographical latitude of discrete points on the route, H ε_σ represents the altitude of the discrete point on the route, σ represents the sequence number of the discrete point on the route, and n ε represents the total number of discrete points of flight ε on the route, v ε Indicates the aircraft's operating speed;

[0063] For a discrete point σ, if:

[0064] λ ε_σ ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+1 ]

[0065] Then the discrete point σ belongs to the spatial unit Cell(i, j, k). The total number of discrete points of route ε in the spatial unit Cell(i, j, k) is n(ε|Cell(i, j, k)).

[0066] Preferably, the method for obtaining the flight space density includes:

[0067] Get the total number of discrete points n(ε|Cell(i, j, k)) in the spatial cell, and calculate the airspace density of the flight ε:

[0068]

[0069] in, represents the airspace density of flight ε during the evaluation period, ΔT represents the evaluation period, and MC represents the number of flight ε during the evaluation period;

[0070] Calculate all N based on the airspace density of the flight ε line The total flight space density of the flight during the evaluation period is:

[0071]

[0072] in, N line The total spatial density of said flights during the evaluation period.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] The present invention combines the spatial density algorithm to realize the quantitative evaluation of the spatiotemporal distribution law of aircraft in UAM dense flight scenarios, laying the foundation for the evaluation and optimization of the operational safety of the overall operation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0076] Figure 1 Schematic diagram of the system structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0077] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0078] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0079] Embodiment 1

[0080] This example uses the concept of spatial density in the field of spacecraft risk assessment to quantitatively describe the spatial distribution of aircraft in low-altitude dense scenes. The spatial density is defined as: the statistical estimate of the number of aircraft contained in a unit volume at a certain spatial location during the assessment period, with the unit of 1 / km 3 .

[0081] In this embodiment, if Figure 1 As shown, a spatial density-based urban air traffic aircraft spatiotemporal distribution assessment system includes: an airspace gridding module, a route discretization module and a spatial distribution assessment module.

[0082] The airspace gridding module is used to discretize the airspace to be evaluated to obtain several spatial units.

[0083] The airspace gridding module includes: a space unit characterization submodule and a space unit volume calculation submodule. The space unit characterization submodule is used to divide the airspace to be evaluated into several space units and characterize the space units:

[0084] Cell(i,j,k)=λ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+1 ]

[0085] λ i =λ min +(i-1)×Δλ,i=1,2,...,N λ

[0086] θ j =θ min +(j-1)×Δθ,j=1,2,…,N θ

[0087] H k =H min +(k-1)×ΔH,k=1,2,...,N H

[0088] Among them, Cell(i, j, k) represents the spatial unit, λ represents longitude, θ represents latitude, H represents height, λ represents the min represents the lower limit of the longitude of the airspace to be evaluated, θ min Indicates the lower latitude limit of the airspace to be evaluated, H min represents the lower limit of the airspace height to be evaluated, Δλ represents the discrete interval step size of longitude, Δθ represents the discrete interval step size of latitude, ΔH represents the discrete interval step size of height, and N λ A discrete number representing longitude, Nθ A discrete number representing longitude, N H Represents a discrete number of longitudes, i, j, k represent natural numbers; the space unit volume calculation submodule calculates the volume of each unit space based on the representation:

[0089]

[0090] Among them, dV(i, j, k) represents the volume of the unit space, r represents the height integration factor, represents the geographic latitude integration factor, and γ represents the geographic longitude integration factor.

[0091] The route discretization module is used to discretize the aircraft route and obtain the route discrete points in the airspace to be evaluated.

[0092] The route discretization module includes: route length calculation submodule and discrete point representation submodule. The route length calculation submodule is used to obtain the starting longitude λ of flight ε up 、Starting point latitude θ up , the end point longitude λ down , end point latitude θ down and the average flight altitude H ε , and calculate the route length:

[0093] D ε =(Re+H ε )×arccos(sinθ up sinθ down +cosθ up cosθ down cos(λ up -λ down ))

[0094] Among them, D ε represents the route length, Re represents the radius of the earth; the total operating time period of flight ε is:

[0095]

[0096] Among them, t ε represents the departure time of flight ε; the discrete point representation submodule is used to obtain the discrete time interval dt of the route. Since the aircraft altitude is much smaller than the radius of the earth, the influence of the earth's curvature on the ground plane of the flight area can be approximately ignored. Therefore, the total number of discrete points corresponding to the route ε is:

[0097]

[0098] Among them, n ε represents the number of discrete points of flight ε on the route, and ceil is the upward rounding function; the representation of the discrete points of the route is obtained based on the route length:

[0099]

[0100] H ε_σ =H ε

[0101] σ=1,2,...n ε

[0102]

[0103] Among them, λ ε_σ Represents the geographic longitude of discrete points on the route, θ ε_σ Indicates the geographical latitude of discrete points on the route, H ε_σ represents the altitude of the discrete point on the route, σ represents the sequence number of the discrete point on the route, and n ε represents the total number of discrete points of flight ε on the route, v ε Indicates the aircraft's operating speed;

[0104] For a discrete point σ, if:

[0105] λ ε_σ ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+1 ]

[0106] Then the discrete point σ belongs to the spatial unit Cell(i, j, k). The total number of discrete points of route ε in the spatial unit Cell(i, j, k) is n(ε|Cell(i, j, k)).

[0107] The spatial distribution evaluation module performs spatial distribution evaluation based on several spatial units and route discrete points to obtain the flight spatial density.

[0108] In this embodiment, the concept of spatial density in the aerospace field is: the average value of the number of aircraft per unit space volume at different spatial locations within a certain evaluation period. Therefore, the spatial density in this field can also be called the "time average" of the spatial distribution of aircraft.

[0109] The spatial distribution assessment module includes: a single flight airspace density assessment submodule and a total airspace density assessment submodule. The single flight airspace density assessment submodule is used to obtain the total number of discrete points n(ε|Cell(i, j, k)) in the spatial cell during the assessment period and calculate the airspace density of a single flight ε:

[0110]

[0111] Where ΔT represents the evaluation period; the number of flight ε during the evaluation period is MC, and the airspace density of flight ε during the evaluation period is calculated as:

[0112]

[0113] Where MC represents the number of flights ε in the evaluation period; the total airspace density evaluation submodule calculates all N based on the airspace density of flight ε. line The total flight space density of flights during the evaluation period is:

[0114]

[0115] in, N line The total flight spatial density of flights during the evaluation period.

[0116] Embodiment 2

[0117] In this embodiment, a method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density includes the following steps:

[0118] S1. Discretize the airspace to be evaluated to obtain several spatial units.

[0119] S1 includes: dividing the airspace to be evaluated into several spatial units and characterizing the spatial units:

[0120] Cell(i,j,k)=λ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+1 ]

[0121] λ i =λ min +(i-1)×Δλ,i=1,2,...,N λ

[0122] θ j =θ min +(j-1)×Δθ,j=1,2,…,N θ

[0123] H k =H min +(k-1)×ΔH,k=1,2,...,N H

[0124] Among them, Cell(i, j, k) represents the spatial unit, λ represents longitude, θ represents latitude, H represents height, λ represents the min represents the lower limit of the longitude of the airspace to be evaluated, θmin Indicates the lower latitude limit of the airspace to be evaluated, H min represents the lower limit of the airspace height to be evaluated, Δλ represents the discrete interval step size of longitude, Δθ represents the discrete interval step size of latitude, ΔH represents the discrete interval step size of height, and N λ A discrete number representing longitude, N θ A discrete number representing longitude, N H Represents a discrete number of longitude, i, j, k represent natural numbers; the volume of each unit space is calculated based on the representation:

[0125]

[0126] Among them, dV(i, j, k) represents the volume of the unit space, r represents the height integration factor, represents the geographic latitude integration factor, and γ represents the geographic longitude integration factor.

[0127] S2. Discrete the aircraft route to obtain discrete route points within the airspace to be evaluated.

[0128] S2 includes: obtaining the starting longitude λ of flight ε up 、Starting point latitude θ up , the end point longitude λ down , end point latitude θ down and the average flight altitude H ε , and calculate the route length:

[0129] D ε =(Re+H ε )×arccos(sinθ up sinθ down +cosθ up cosθ down cos(λ up -λ down ))

[0130] Among them, D ε represents the route length, Re represents the radius of the earth; the total operating time period of flight ε is:

[0131]

[0132] Among them, t ε represents the departure time of flight ε; obtain the discrete time interval dt of the route. Since the aircraft altitude is much smaller than the radius of the earth, the influence of the earth's curvature on the ground plane of the flight area can be approximately ignored. Therefore, the total number of discrete points corresponding to the route ε is:

[0133]

[0134] Among them, nε represents the number of discrete points of flight ε on the route, and ceil is the upward rounding function; the representation of the discrete points of the route is obtained based on the route length:

[0135]

[0136] H ε_σ =H ε

[0137] σ=1,2,...n ε

[0138]

[0139] Among them, λ ε_σ Represents the geographic longitude of discrete points on the route, θ ε_σ Indicates the geographical latitude of discrete points on the route, H ε_σ represents the altitude of the discrete point on the route, σ represents the sequence number of the discrete point on the route, and n ε represents the total number of discrete points of flight ε on the route, v ε Indicates the aircraft's operating speed;

[0140] For a discrete point σ, if:

[0141] λ ε_σ ∈[λ i ,λ i+1 ]∩θ∈[θ j ,θ j+1 ]∩H∈[H k ,H k+1 ]

[0142] Then the discrete point σ belongs to the spatial unit Cell(i, j, k). The total number of discrete points of route ε in the spatial unit Cell(i, j, k) is n(ε|Cell(i, j, k)).

[0143] S3. Perform spatial distribution evaluation based on the plurality of spatial units and the discrete points of the routes to obtain flight spatial density.

[0144] S3 includes: obtaining the number of discrete points n(ε|Cell(i, j, k)) in the spatial cell during the evaluation period, and calculating the airspace density of a single flight ε:

[0145]

[0146] Where ΔT represents the evaluation period; the number of flight ε during the evaluation period is MC, and the airspace density of flight ε during the evaluation period is calculated as:

[0147]

[0148] Where MC represents the number of flights ε in the evaluation period; the total airspace density evaluation submodule calculates all N based on the airspace density of flight ε. line The total flight space density of flights during the evaluation period is:

[0149]

[0150] in, N line The total flight spatial density of flights during the evaluation period.

[0151] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A spatial density-based urban air traffic aircraft spatiotemporal distribution assessment system, characterized in that: include: Airspace gridding module, route discretization module and spatial distribution assessment module; The airspace gridding module is used to discretize the airspace to be evaluated to obtain a number of space units; The route discretization module is used to discretize the aircraft route to obtain route discrete points within the airspace to be evaluated; The spatial distribution evaluation module performs spatial distribution evaluation based on a number of the spatial units and the route discrete points to obtain flight spatial density.

2. The urban air traffic aircraft spatiotemporal distribution evaluation system based on spatial density according to claim 1, characterized in that: The spatial gridding module includes: a spatial unit characterization submodule and a spatial unit volume calculation submodule; The spatial unit characterization submodule is used to divide the airspace to be evaluated into a plurality of spatial units and characterize the spatial units: Cell(i,j,k)=λ∈[λ i ,l i+1 ]∩θ∈[θ j ,the j+1 ]∩H∈[H k ,H k+1 ] l i =λ min +(i-1)×Δλ,i=1,2,...,N λ i j =θ min +(j–1)×Δθ,j=1,2,...,N θ H k =H min +(k-1)×ΔH,k=1,2,...,N H Among them, Cell(i, j, k) represents the spatial unit, λ represents longitude, θ represents latitude, H represents height, λ represents the min represents the lower limit of the longitude of the airspace to be evaluated, θ min Indicates the lower latitude limit of the airspace to be evaluated, H min represents the lower limit of the airspace height to be evaluated, Δλ represents the discrete interval step size of longitude, Δθ represents the discrete interval step size of latitude, ΔH represents the discrete interval step size of height, and N λ A discrete number representing longitude, N θ A discrete number representing longitude, N H Represents the discrete number of longitude, i, j, k represent natural numbers; The space unit volume calculation submodule calculates the volume of each of the unit spaces based on the representation: Among them, dV(i, j, k) represents the volume of the unit space, r represents the height integration factor, θ represents the geographic latitude integration factor, and γ represents the geographic longitude integration factor.

3. The urban air traffic aircraft spatiotemporal distribution evaluation system based on spatial density according to claim 2, characterized in that: The route discretization module includes: a route length calculation submodule and a discrete point representation submodule; The route length calculation submodule is used to obtain the starting longitude λ of flight ε up 、Starting point latitude θ up , the end point longitude λ down , end point latitude θ down and the average flight altitude H ε , and calculate the route length: D ε =(Re+H ε )×arccos(sinθ up sinth down +cosθ up cosθ down cos(λ up -l down )) Among them, D ε represents the length of the route, Re represents the radius of the earth; The discrete point representation submodule is used to obtain the discrete time interval dt of the route, and obtain the representation of the discrete points of the route based on the route length: H ε_σ =H ε σ=1,2,...n ε Among them, λ ε_σ Represents the geographic longitude of discrete points on the route, θ ε_σ Indicates the geographical latitude of discrete points on the route, H ε_σ represents the altitude of the discrete point on the route, σ represents the sequence number of the discrete point on the route, and n ε represents the total number of discrete points of flight ε on the route, v ε Indicates the aircraft's operating speed; For a discrete point σ, if: l ε_σ ∈[λ i ,l i+1 ]∩θ∈[θ j ,the j+1 ]∩H∈[H k ,H k+1 ] Then the discrete point σ belongs to the spatial unit Cell(i, j, k); the total number of discrete points of the route ε in the spatial unit Cell(i, j, k) is n(ε|Cell(i, j, k)).

4. The urban air traffic aircraft spatiotemporal distribution evaluation system based on spatial density according to claim 3, characterized in that: The spatial distribution assessment module includes: a single flight airspace density assessment submodule and a total airspace density assessment submodule; The single flight airspace density assessment submodule is used to obtain the total number of discrete points n(ε|Cell(i, j, k)) in the spatial unit and calculate the airspace density of the flight ε: in, represents the airspace density of flight ε during the evaluation period, ΔT represents the evaluation period, and MC represents the number of flight ε during the evaluation period; The total airspace density evaluation submodule calculates all N based on the airspace density of the flight ε. line The total flight space density of the flight during the evaluation period is: in, N line The total spatial density of said flights during the evaluation period.

5. A method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density, the method being applied to the evaluation system according to any one of claims 1 to 4, characterized in that: The following steps are involved: Discretize the airspace to be evaluated to obtain several spatial units; Performing discretization operation on the aircraft route to obtain discrete route points of the route within the airspace to be evaluated; A spatial distribution evaluation is performed based on the plurality of spatial units and the discrete points of the routes to obtain the flight spatial density.

6. The method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density according to claim 5, characterized in that: The method of obtaining the plurality of said spatial units comprises: The airspace to be evaluated is divided into a plurality of space units, and the space units are characterized: Cell(i,j,k)=λ∈[λ i ,l i+1 ]∩θ∈[θ j ,the j+1 ]∩H∈[H k ,H k+1 ] l i =λ min +(i-1)×Δλ,i=1,2,...,N λ H k =H min +(k-1)×ΔH,k=1,2,...,N H Among them, Cell(i, j, k) represents the spatial unit, λ represents longitude, θ represents latitude, H represents height, λ represents the min represents the lower limit of the longitude of the airspace to be evaluated, θ min Indicates the lower latitude limit of the airspace to be evaluated, H min represents the lower limit of the airspace height to be evaluated, Δλ represents the discrete interval step size of longitude, Δθ represents the discrete interval step size of latitude, ΔH represents the discrete interval step size of height, and N λ A discrete number representing longitude, N θ A discrete number representing longitude, N H Represents the discrete number of longitude, i, j, k represent natural numbers; The volume of each of the unit spaces is calculated based on the representation: Among them, dV(i, j, k) represents the volume of the unit space, r represents the height integration factor, θ represents the geographic latitude integration factor, and γ represents the geographic longitude integration factor.

7. The method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density according to claim 6, characterized in that: The method for obtaining the discrete points of the route includes: Get the starting longitude λ of flight ε up 、Starting point latitude θ up , the end point longitude λ down , end point latitude θ down and the average flight altitude H ε , and calculate the route length: D ε =(Re+H ε )×arccos(sinθ up sinth down +cosθ up cosθ down cos(λ up -l down )) Among them, D ε represents the length of the route, Re represents the radius of the earth; Obtain the discrete time interval dt of the route, and obtain the representation of the discrete points of the route based on the length of the route: H ε_σ =H ε σ=1,2,...n ε Among them, λ ε_σ Represents the geographic longitude of discrete points on the route, θ ε_σ Indicates the geographical latitude of discrete points on the route, H ε_σ represents the altitude of the discrete point on the route, σ represents the sequence number of the discrete point on the route, and n ε represents the total number of discrete points of flight ε on the route, v ε Indicates the aircraft's operating speed; For a discrete point σ, if: l ε_σ ∈[λ i ,l i+1 ]∩θ∈[θ j ,the j+1 ]∩H∈[H k ,H k+1 ] Then the discrete point σ belongs to the spatial unit Cell(i, j, k); the total number of discrete points of the route ε in the spatial unit Cell(i, j, k) is n(ε|Cell(i, j, k)).

8. The method for evaluating the spatiotemporal distribution of urban air traffic aircraft based on spatial density according to claim 7, characterized in that: The method for obtaining the flight space density includes: Get the total number of discrete points n(ε|Cell(i, j, k)) in the spatial cell, and calculate the airspace density of the flight ε: in, represents the airspace density of flight ε during the evaluation period, ΔT represents the evaluation period, and MC represents the number of flight ε during the evaluation period; Calculate all N based on the airspace density of the flight ε line The total flight space density of the flight during the evaluation period is: in, N line The total spatial density of said flights during the evaluation period.

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