1. The POI-based urban air traffic flight carrier take-off and landing point addressing method is characterized by comprising the following steps of:

step 1, establishing a POI information base of the area;

the information base is used for definitely analyzing the required data, determining the attribute type of the element, determining the boundary line of the subarea area and determining the coordinate point of the element point;

step 2, carrying out urban area function division based on POI data;

in the functional area identification, a city is generally divided into a single functional area and a mixed functional area, and is judged according to the fact that the density of each point type data point exceeds 50%, and the POI is visualized through an ArcGIS nuclear density method;

dividing the original block into equal blocks with almost the same area according to an equal principle; on the basis, grid networks are formed, each grid is used as a research area, and primary screening of site selection and qualification is carried out by combining the population quantity of the area and the income of each person;

if the population density tau of the location is larger than the population density a and the per-capita income theta of the location is larger than the per-capita income b, setting a take-off and landing point of the flight carrier in the alternative area;

the areas where the take-off and landing points are set should be business areas, residential areas, and mixed areas;

step 3, screening all the alternative points of the alternative area based on the suitability;

and 4, comprehensively checking by combining the number n of the optional sets, wherein the requirements are as follows: the distance between two adjacent lifting points cannot be too close and should be dispersed as much as possible, and the distance between two lifting points should exceed twice of the radiation range of a single lifting point;

S＝distance(a_i,a_j)≥2ri,j＝(1，2,3...n,i≠j) (1-5)

s represents the distance of the bright spot; a represents some optimal point; r represents the radiation range of a single take-off and landing point;

and 5, obtaining an optimal site selection point.

2. The POI-based urban air traffic flight vehicle take-off and landing point locating method according to claim 1, wherein in step 2, the POI is classified into six categories of residential land, commercial service facility land, green land and square land, industrial land, public management and public service facility land and road and traffic facility land:

at each functional area unit, a type proportion function is constructed to identify the functional unit as follows:

i represents a POI type;

E_ifrequency density of the type POI in the ith accounts for the total number of the type POI;

n_irepresenting the number of the ith type POI in the plot unit;

N_irepresenting the total number of the i-th POI;

T_iindicating that the proportion of the ith type POI accounts for the frequency of all POI types in the unit.

Calculating the frequency density and the type proportion of each unit according to a formula, and researching and determining that the type proportion value is 50% as a standard for judging the functional property of the unit; determining:

T_imore than or equal to 50 percent of a certain single functional area;

T_iless than or equal to 50%, a mixing function, and the type of mixing is dependent on the first three main types of POI;

E_i0, null.

3. The POI-based urban air traffic flight vehicle take-off and landing point addressing method according to claim 1, wherein in step 3, the available land is searched for as the alternative take-off and landing point in the alternative area, which is required to satisfy:

the area of the plane is larger than the area required by the construction of the lifting point;

the urban land type is met;

building height h exceeding the plane of the alternative points cannot exceed a limit value, and if the threshold level is epsilon, h is more than or equal to epsilon;

the total gradient of the lifting point construction site in any direction cannot exceed 3 percent, and the local gradient of any place cannot exceed 5 percent;

no obstacles and no irregularities that may adversely affect the takeoff or landing of the aircraft;

from the viewpoint of noise generated by the flying vehicle, the site is far away from public facilities;

from the safety perspective, the site selection needs to be far away from explosive facilities.

4. The POI-based urban air traffic flight vehicle take-off and landing point addressing method according to claim 3, wherein in step 3, all candidate points in the selected network grid area are screened, and influence factors thereof are quantified as follows, all the following levels are set to be 1, 2,3,4.. 10 according to actual conditions, and the following conditions are considered:

(1) close to the stations of other transportation modes, the grade is E₂＝α；

(2) Enough land and relatively low cost, and the cost grade of the land is E₃＝β；

(3) Combining flight safety and energy consumption, the density of surrounding buildings and the grade E₃＝δ；

(4) The environmental comprehensive factors affecting the flight, such as wind speed, geological environment, etc., are set to be E₄＝λ；

(5) Aircraft noise level, given as E₅＝μ；

(6) Local working density is rated as

Setting the weight coefficient sum of a certain alternative point in a certain grid network area:

therefore, the address points of the area are:

K＝min{K_i}i＝1,2…n (1-4)

and the alternative point i is a place needing to establish a take-off and landing point in the alternative area, and so on until all the selectable sets of the take-off and landing points in the research area are found.

Background

The rapid development of aeronautical technology now enables the creation of fast, lightweight, low-noise, more environmentally friendly personal aircraft. Therefore, the Urban Air Mobility (UAM) is a new transport mode, and the UAM promotes multi-mode intermodal and point-to-point transport in the metropolitan area by using the Urban Air traffic flight vehicle network as a central link of a task. Urban air transport can provide many benefits to consumers and cities, including diversified traffic options, expanding the traffic footprint of economic basins, and increasing the flexibility of urban traffic networks.

An electric vertical take-off and landing aircraft of a small-sized all-electric or hybrid electric vertical take-off and landing aircraft is a novel aircraft generated along with the development of urban traffic in recent years, and generally adopts an unconventional design to more closely combine aerodynamic and electric propulsion technologies, so that the aircraft can be used as an urban public transport vehicle and a private aircraft. The electric vertical takeoff and landing aircraft developed at present are mostly used for urban air traffic transportation. The main reason is that the energy cost of the power grid is only 30% of the aviation fuel cost due to the fact that the electric propulsion system is compared with the internal combustion engine propulsion system, and the efficiency of the electric propulsion system is 2-4 times that of the internal combustion engine.

To achieve on-demand vertical take-off and landing within a city, infrastructure and operational requirements must be tailored to the pattern of local demand. The extent of infrastructure that needs to be developed in any given metropolitan area depends not only on the demand and the mode of efficient operation, but also on the current infrastructure and whether the infrastructure needs to be repurposed. In many cases, the suitability of existing infrastructure and the scale of the associated infrastructure may be inadequate. Under such conditions, the establishment of suitable take-off and landing points for urban air traffic flight vehicles and the planning thereof are such that the most efficient flight routes become critical.

Therefore, the selection of the urban air traffic take-off and landing point becomes an important measure for developing the UAM system, has extremely important theoretical significance and practical value, and provides technical support for subsequent UAM route planning and management thereof.

The existing technology mainly expands the helicopter platform to select the site from a local angle, simultaneously considers the requirements of emergency rescue and personal trip, and expands the site selection of the helicopter from microscopic angles such as a safety angle, a flight angle and the like. Namely, the traditional site selection method needs to firstly carry out site survey by means of experienced experts and then carry out site selection analysis according to experience and intuition. The method for selecting the address has the disadvantages that the time is long, professional staff is needed to participate, and the complicated address selection elements and the mutual influence thereof are difficult to accurately and comprehensively consider so as to determine the address selection scheme. The prior art is only used for emergency use and personal requirements, and large-scale coverage is not available, so that the current facilities have considerable unevenness, the city cannot be effectively covered, and the mode which depends on the existing facilities cannot generate certain cross interference with other facilities, and the maximization of the flight efficiency cannot be realized. And the utilization of the existing facilities can limit the exertion of the use value of the air traffic, so that the air traffic mode cannot be really and widely popularized.

Disclosure of Invention

Aiming at the technical problems, the invention establishes a basic database through POI data, and further analyzes the characteristics of potential urban infrastructure, population conditions and the like. And then, carrying out regional function division on the given urban region to form an urban block. And a primary selection is carried out aiming at the site selection qualification by combining population and economic factors. On the basis, building points suitable for all the alternative take-off and landing points are found out in a grid area with site selection qualification based on suitable conditions, the optimal take-off and landing point site selection is obtained by fully considering the requirements of the take-off and landing points, the characteristics of the flight carrier and the surrounding environment of the alternative take-off and landing points, verification is carried out by combining the characteristics of the take-off and landing points, and the applicability of the site selection is confirmed.

POI (Point of interest): the data of landmark buildings and geographic entities closely related to the life of people, such as schools, hospitals, malls, parks, government institutions and the like. The POI data describes the spatial position and attribute information of the geographic entities, has large data sample amount and rich coverage information, and can reflect various activities of cities to a certain extent. The characteristics that POI data and urban spatial layout are closely related can be utilized, information statistics, geographical positioning and expression can be carried out on various public service facilities in the city, great convenience is provided for users, and the users are helped to feel the distribution of various geographical entities more intuitively, so that urban structures can be better understood.

The specific technical scheme is as follows:

a POI-based urban air traffic flight carrier take-off and landing point addressing method comprises the following steps:

and step 1, establishing a POI information base of the area. The information base is data required for explicit analysis, and is used for specifying the attribute type of an element, specifying the boundary line of a partition area, specifying the coordinate point of an element point, and the like.

Step 2, carrying out urban area function division based on POI data; in the functional area identification, a city is generally divided into a single functional area and a mixed functional area, and is judged according to the fact that the density of each point type data point exceeds 50%, and the POI can be visualized through an ArcGIS nuclear density method.

POI is divided into six categories of residential land, commercial service facility land, green land and square land, industrial land, public management and public service facility land and road and transportation facility land:

at each functional area unit, a type proportion function is constructed to identify the functional unit as follows:

i represents a POI type;

E_ifrequency density of the type POI in the ith accounts for the total number of the type POI;

n_irepresenting the number of the ith type POI in the plot unit;

N_irepresenting the total number of the i-th POI;

T_iindicating that the proportion of the ith type POI accounts for the frequency of all POI types in the unit.

And calculating the frequency density and the type proportion of each unit according to a formula, and researching and determining that the type proportion value is 50% as a standard for judging the functional property of the unit. Can determine

T_iMore than or equal to 50 percent of a certain single functional area;

T_iless than or equal to 50%, a mixing function, and the type of mixing is dependent on the first three main types of POI;

E_i0, null.

On the basis of the original blocks, the original blocks are divided into equal blocks with almost the same area according to the equal principle. On the basis, grid networks are formed, each grid is used as a research area, and primary screening of site selection and qualification is carried out by combining the population quantity of the area and the income of all people.

If the population density tau at the location is larger than the population density a and the per-capita income theta at the location is larger than the per-capita income b, the alternative area can be provided with a flying carrier take-off and landing point. The areas where the take-off and landing points are set should be business areas, residential areas and mixed areas.

And 3, screening all the alternative points of the alternative areas based on the suitability, wherein the screening is mainly carried out by a comparative analysis method, and the comprehensive consideration is mainly focused on living, commercial sites, public facilities, transportation facilities and the like:

the need to meet the need in finding available land as an alternative take-off and landing point in an alternative area

(1) The area of the plane is larger than the area required by the construction of the lifting point;

(2) the urban land type is met;

(3) building height h exceeding the plane of the alternative points cannot exceed a limit value, and if the threshold level is epsilon, h is more than or equal to epsilon;

(4) the total gradient of the lifting point construction site in any direction cannot exceed 3 percent, and the local gradient of any place cannot exceed 5 percent;

(5) no obstacles and no irregularities that may adversely affect the takeoff or landing of the aircraft;

(6) from the viewpoint of noise generated by the flight vehicle, the flight vehicle is located far away from other public facilities such as schools, hospitals and the like.

(7) From the safety perspective, the site selection needs to be far away from explosive facilities such as oil stations and the like.

Screening all the alternative points of the selected network grid area, quantifying the influence factors of the alternative points, setting the following all grades to be 1, 2,3,4.. 10 according to the actual situation, and considering the following conditions:

(1) close to the stations of other transportation modes, the grade is E₂＝α；

(2) Enough land and relatively low cost, and the cost grade of the land is E₃＝β；

(3) Combining flight safety and energy consumption, the density of surrounding buildings and the grade E₃＝δ；

(4) The environmental comprehensive factors affecting the flight, such as wind speed, geological environment, etc., are set to be E₄＝λ；

(5) Aircraft noise level, given as E₅＝μ。

(6) Local working density is rated as

Setting the weight coefficient sum of a certain alternative point in a certain grid network area:

therefore, the address points of the area are:

K＝min{K_i} i＝1,2…n (1-4)

and the alternative point i is a place needing to establish a take-off and landing point in the alternative area, and so on until all the selectable sets of the take-off and landing points in the research area are found.

And 4, comprehensively checking by combining the number n of the optional sets, wherein the requirements are as follows: the adjacent take-off and landing points are not too close to each other and should be dispersed as much as possible, and the distance between two take-off and landing points should exceed twice the radiation range of a single take-off and landing point.

S＝distance(a_i,a_j)≥2r i,j＝(1，2,3...n,i≠j) (1-5)

S represents the distance of the bright spot; a represents some optimal point; r denotes the radiation range of a single take-off and landing point.

And 5, obtaining an optimal site selection point.

The technical scheme provided by the invention has the following technical effects:

1. the site selection process of the air city traffic is systematically explained, so that the site selection process is more comprehensive.

2. The technology fully considers the outline of the existing city and the existing traffic system.

3. An optimal set of site points for the study area may be presented.

Drawings

FIG. 1 is a flow chart of a method of the present invention;

FIG. 2a is before the city function partition of the embodiment;

FIG. 2b is after the city function division of the embodiment;

FIG. 3 illustrates an exemplary method for setting a threshold for a take-off and landing point.

Detailed Description

The specific technical scheme of the invention is described by combining the embodiment.

As shown in fig. 1, the origin and landing points of the urban air traffic flight vehicle are selected as follows:

step 1, establishing a POI database, determining data required by the patent research, further determining basic attributes of the POI, and classifying and identifying.

And 2, counting the total number of POIs in each grid cell and the number of POIs in each cell to obtain the overall distribution condition of the POIs in the research area, and dividing the grid cell into a single function area or a mixed area according to the number and proportion of various POIs in the grid cell and the formula (1-1) and the formula (1-2). The single functional area can be divided into six types, namely residential land, commercial service facility land, greenbelt and square land, industrial land and public management and public service facility, as shown in table 1.

TABLE 1 City function-division Table

Type of function	Case(s)
		Residential land	Residential area, community center, etc
Public facilities	Schools, fire-fighting, public security, government offices and the like
		Traffic facilities	Subway station, bus station, toll station, service area, etc
Fields for industry	Factories, companies, industrial parks, etc
		Green space squares	Urban squares, parks, zoos, or the like
Business service facility	Restaurants, supermarkets, hotels, business companies and the like

Schematic diagrams of the urban land types before and after division are shown in fig. 2a and 2 b.

And by combining the characteristics of the novel traffic mode, data of the population and per capita income of a certain grid area are collected, and the primary screening of site selection and qualification is performed by combining the data of the population and the per capita income of the certain grid area. The two factors are selected in consideration of the fact that a large population is guaranteed by the novel transportation mode and is a basic premise that long-term operation can be carried out in the future. Meanwhile, an important objective factor influencing travel demands is enough income which can be controlled at will, and the important objective factor determines whether a user can go out and the consumption capacity when the user goes out. In view of both, the areas where urban air traffic is located are mainly concentrated on business districts and residential and mixed areas.

As shown in FIG. 3, if τ ≧ a and θ ≧ b are satisfied, the alternative area can be set with the takeoff and landing point of the flying vehicle. The areas where the take-off and landing points are set should be business areas, residential areas and mixed areas.

From the flow chart, if τ ≧ a and θ ≧ b (which can be set as appropriate, e.g., a and b can be set as a median) are satisfied, the alternative area can be set as the flying vehicle takeoff and landing point. Thus, the region where the take-off and landing point is set is mainly concentrated on the business district, the residential district, the public facilities, the transportation facilities and the like.

And 3, performing secondary primary screening on all the alternative areas in a targeted manner based on the conditions required to be met by the site selection points, wherein the conditions in the process of searching available land in the alternative areas as alternative take-off and landing points need to be met intensively. The conditions that need to be satisfied are as follows:

(1) the area of the plane is larger than the area required by the construction of the lifting point;

(2) the urban land type is met;

(3) building height h exceeding the plane of the alternative points cannot exceed a limit value, and if the threshold level is epsilon, h is more than or equal to epsilon;

(4) the total gradient of the lifting point construction site in any direction cannot exceed 3 percent, and the local gradient of any place cannot exceed 5 percent;

(5) no obstacles and no irregularities that may adversely affect the takeoff or landing of the aircraft;

(6) from the viewpoint of noise generated by the flight vehicle, the flight vehicle is located far away from other public facilities such as schools, hospitals and the like.

(7) From the safety perspective, the site selection needs to be far away from explosive facilities such as oil stations and the like.

Secondary screening requires field investigation and accurate data acquisition. After the secondary initial screening, the points that do not meet the constraint are moved out of the alternate point set.

Secondly, screening all the alternative points of the selected network grid area, quantifying the influence factors of the alternative points, setting the following all levels to be 1, 2,3,4.. 10 according to the actual situation (the setting levels can refer to the sequential arrangement of all sample data sets to further obtain the levels), and considering the following conditions:

(1) close to the stations of other transportation modes, the grade is E₂＝α；

(2) Enough land and relatively low cost, and the cost grade of the land is E₃＝β；

(3) Combining flight safety and energy consumption, the density of surrounding buildings and the grade E₃＝δ；

(4) The environmental comprehensive factors affecting the flight, such as wind speed, geological environment, etc., are set to be E₄＝λ；

(5) Aircraft noise level, given as E₅＝μ。

(6) Local working density is rated as

Setting the weight coefficient sum of a certain alternative point in a certain grid network area:

and selecting the C point with the minimum condition grade as an alternative site selection point according to the condition grade sum of each grid area and the number C of the origin and landing points of the research area.

K＝min{K_i} i＝1,2…n (1-4)

The alternative points i are the places in the alternative area where the rising and falling points need to be established, until C alternative points are found, the C alternative points form an optional set, and the points per se meet the site selection requirement.

And 4, referring to a site selection mode of the ground public transport station, the radiation range of the station needs to be considered in site selection, so that the distance between any two lifting points needs to be fully considered when the selectable set of the lifting points is verified, the verification can be performed by a formula (1-5), and if the selectable set of the lifting points does not accord with the radiation range constraint between the two lifting points, the selectable set of the lifting points needs to be adjusted until the whole selectable set of the lifting points accords with the requirement.

S＝distance(a_i,a_j)≥2r i,j＝(1，2,3...n,i≠j) (1-5)

S represents the distance of the bright spot; a represents some optimal point; r denotes the radiation range of a single take-off and landing point.

And 5, the verified optional set obtained in the first four steps is used as a starting and landing point addressing scheme of the research area, and the basic goal is achieved.