A method for constructing and evaluating eVTOL landing site networks in urban environments

Abstract

The present invention discloses a method for constructing and evaluating an eVTOL landing and take-off site network in an urban environment. 1. Evaluate the technical feasibility of eVTOL landing and take-off site construction, and all landing and take-off sites that do not meet the technical constraints of eVTOL landing and take-off site construction should be screened out. 2. Evaluate the eVTOL riding demand density, and if the riding demand density does not meet the standard limit, it should be deleted. 3. Measure the feasibility of the landing and take-off site from the perspective of the convenience of transfer at the landing and take-off site, and any site with a walking time exceeding the standard from the surrounding transportation hub should be deleted. 4. Calculate the partial rank correlation coefficient, and all sites that do not meet the partial rank correlation coefficient standard will be deleted. 5. Construct an eVTOL landing and take-off site network. 6. Calculate the total degree value of the eVTOL landing and take-off site. Evaluate the landing and take-off sites that play a key role in the overall eVTOL landing and take-off site network based on the total degree value of the landing and take-off site. The present invention realizes the comprehensive processing of urban terrain and traffic conditions, and can be used to measure the feasibility of multiple factors restricting the location of the landing and take-off site.

Description

Technical Field

[0001] The present invention relates to a method for constructing and evaluating an eVTOL landing site network from the perspective of technology and demand, and in particular to a method for constructing and evaluating an eVTOL landing site network in an urban environment. Background Art

[0002] Since its inception, the concept of Urban Air Mobility (UAM) has garnered widespread attention worldwide. As a new mode of transportation, UAM offers advantages such as environmental friendliness, high speed, and low noise, and it has the potential to significantly alleviate ground traffic pressures. To fully leverage UAM's potential, evaluating takeoff and landing site locations based on both technical standards and passenger needs is a key step in UAM development.

[0003] In urban environments, the location of eVTOL (electric vertical take-off and landing) landing sites is constrained by multiple factors, including obstacles, airspace, infrastructure, and passenger demand. Obstacles and airspace directly impact the operational safety of eVTOL landing sites; surrounding infrastructure impacts daily operations; and passenger demand directly determines the service capabilities and profitability of UAM systems.

[0004] Existing assessment standards and regulations primarily constrain landing and takeoff site locations based on obstacles and airspace, neglecting infrastructure. However, eVTOLs inevitably require charging, maintenance, and repair at landing and takeoff sites, consuming significant amounts of electricity and placing significant demands on regional power grid capacity. Furthermore, existing standards fail to consider passenger needs. Ignoring passenger needs will undermine the system's service capabilities and, consequently, hinder the generation of revenue to support its daily operations. Summary of the Invention

[0005] To address the shortcomings of existing evaluation standards, the present invention provides a method for constructing and evaluating an eVTOL take-off and landing site network in an urban environment.

[0006] The technical solution adopted by the present invention is: a method for constructing and evaluating an eVTOL take-off and landing site network in an urban environment, comprising the following steps:

[0007] 1. Extraction of geographic data of the pre-construction area of ​​the take-off and landing field.

[0008] 2. Select the pre-construction area that meets the technical constraints for the construction of the take-off and landing field.

[0009] 3. Determine the passenger flow attraction factors in the pre-construction area.

[0010] 4. Calculation of Ride Demand

[0011] The demand for rides is calculated based on the traffic passenger flow in the pre-construction area, the number of business office population, the road congestion coefficient, the passenger flow in the scenic area and the passenger flow attraction factor of the take-off and landing area.

[0012] V. Ride Demand Density Assessment

[0013] Solve the riding demand density based on the riding demand volume. The riding demand density should meet the riding demand density assessment standard. .

[0014] VI. Analysis of Transfer Convenience at Take-off and Landing Airports

[0015] The walking time from the pre-construction area of ​​the landing field to the surrounding traffic is introduced, and the walking time does not exceed the maximum acceptable walking time of the survey.

[0016] 7. Build a take-off and landing field network

[0017] Calculate the simple correlation coefficient and partial rank correlation coefficient between any two pre-construction areas; establish take-off and landing fields and construct a take-off and landing field network in the pre-construction areas where the partial rank correlation coefficient is greater than or equal to the correlation coefficient test standard.

[0018] 8. Evaluating the Traffic Characteristics of the Landing and Take-off Network

[0019] The total degree value of each landing field is calculated based on the landing field network; the landing field with a larger total degree value has a greater impact on the overall eVTOL landing field network.

[0020] In step 2, the technical constraints for the construction of the take-off and landing field include: take-off and landing field terrain constraints, take-off and landing field airspace restriction range, take-off and landing field noise constraints, take-off and landing field power grid capacity constraints, and take-off and landing field communication, navigation and surveillance system signal strength constraints.

[0021] The landing field terrain constraint in the landing field construction technical constraint condition is based on the landing field construction standards issued by EASA and FAA. As i At least set L × L , L is the side length of the apron of the take-off and landing field.

[0022] At the same time, the obstacle height around the pre-construction area of ​​the take-off and landing field Oh i Cannot exceed the total height of the take-off and landing apron H + H 1 , H is the vertical take-off height of the eVTOL, H 1 is the height at which the eVTOL surpasses obstacles within 100 m during the climb phase after vertical takeoff; the expressions are:

[0023] As i ≥ L × L (1);

[0024] Oh i ≤ H + H 1 (2).

[0025] The airspace restriction range of the take-off and landing field in the technical constraints for the construction of the take-off and landing field does not overlap with the publicly released airspace restriction zone and restricted area location.

[0026] The landing field noise constraint in the landing field construction technical constraint conditions is: the actual perceived noise level in the landing field pre-construction area L 1 No higher than the noise emission standard St noise , the expression is:

[0027] L 1 ≤ St noise (3).

[0028] The grid capacity constraint of the landing field in the technical constraint conditions of the landing field construction is: the landing field pre-construction area i Available grid capacity P i ag Greater than or equal to the charging power of a single eVTOL P 1 , the expression is:

[0029] P i ag ≥ P 1 (4);

[0030] Where, the take-off and landing field pre-construction area i Available grid capacity P i ag The calculation formula is:

[0031] P i ag = (1- K ) × P L - P u (5);

[0032] P L = P G - P u (6);

[0033] Where, P L is the remaining grid capacity; P G is the total capacity of the power grid; P u is the used grid capacity; K It is the percentage of reserved grid capacity to remaining grid capacity.

[0034] The signal strength constraint of the communication, navigation and monitoring system of the take-off and landing field in the technical constraint conditions of the take-off and landing field construction is as follows: obtain the daily received signal strength at the pre-construction area of ​​the take-off and landing field Sr i Minimum value, and the receiving signal strength standard of the communication, navigation and monitoring system of the take-off and landing field St signal By comparison, the daily received signal strength at the take-off and landing field pre-construction area is greater than or equal to the received signal strength standard of the communication, navigation and surveillance system of the take-off and landing field. St signal , the expression is:

[0035] Sr i ≥ St signal (7).

[0036] In step 4, the commuting demand of the business office area in the pre-construction area that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i and the number of business office population W i , calculate the commuting demand of business office areas A i , and then calculate the total commuting demand of the business office area Cd i :

[0037] A i = W i × Atr i (8);

[0038] Cd i =∑ A i (9).

[0039] The tourism demand for scenic spots in the pre-construction area that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i and the flow of people in scenic spots VP i Calculate the tourism demand for scenic spots B i , and then calculate the total tourism demand of the scenic area Td i :

[0040] B i = VP i × Atr i (10);

[0041] Td i =∑ B i (11).

[0042] The travel demand in the pre-construction area that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i Traffic passenger flow F i , calculate the travel demand of traffic C i , and then calculate the total travel demand T i :

[0043] C i = F i × Atr i (12);

[0044] T i =∑ C i (13).

[0045] The traffic congestion situation of roads in the pre-construction area that meets the technical constraints of the take-off and landing field construction, and the average congestion coefficient is calculated using the congestion coefficient of each road section Aver i , the expression is as follows:

[0046] (14);

[0047] Where, Cg i For road sectionsi Road congestion coefficient; n is the total number of road sections in the pre-construction area; then the average congestion coefficient Aver i Compare to the smooth travel time obtained from the map software Ub i Multiply them to get the traffic congestion situation in the pre-construction area. At i :

[0048] At i = Aver i × Ub i (15).

[0049] The beneficial effects produced by the present invention are:

[0050] 1. This invention obtains grid-related data and calculates available grid capacity, thereby ensuring the daily operation of the eVTOL landing site. It also makes up for the shortcomings of the landing site selection assessment standards in terms of infrastructure considerations.

[0051] 2. The present invention takes transfer convenience constraints into consideration, which helps to enhance multimodal transport and improve the convenience of passenger travel.

[0052] 3. The present invention systematically analyzes the demand for eVTOL rides in the pre-construction area of ​​the take-off and landing site, so that the take-off and landing site can fully serve passenger needs and alleviate ground traffic pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a flow chart of a method for constructing and evaluating an eVTOL take-off and landing site network in an urban environment according to the present invention;

[0054] Figure 2 A network diagram of an eVTOL take-off and landing site constructed for an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The present invention will be further described below with reference to the accompanying drawings and examples.

[0056] Reference Figure 1 :Step 1. Extract geographic data of the landing field pre-construction area

[0057] The geographic data of the pre-construction area of ​​the landing and take-off airport are extracted from various public data and geographic information service platforms; the geographic data of the pre-construction area of ​​the landing and take-off airport include: the location of buildings in the pre-construction area of ​​the landing and take-off airport, the height of buildings in the pre-construction area of ​​the landing and take-off airport, the scope of the airspace restricted area in the pre-construction area of ​​the landing and take-off airport, the infrastructure situation in the pre-construction area of ​​the landing and take-off airport, the traffic passenger flow in the pre-construction area of ​​the landing and take-off airport, the number of business office population in the pre-construction area of ​​the landing and take-off airport, the road congestion coefficient in the pre-construction area of ​​the landing and take-off airport, and the flow of people in scenic spots in the pre-construction area of ​​the landing and take-off airport.

[0058] In this embodiment, the passenger flow in the pre-construction area of ​​the landing and take-off field at 21 locations, the number of business office residents in the pre-construction area, the flow of people in the scenic area in the pre-construction area, and the road congestion coefficient in the pre-construction area of ​​the landing and take-off field are extracted, as shown in Table 1:

[0059] Table 1 Numerical table of various raw data

[0060] .

[0061] Step 2: Screen the pre-construction area that meets the technical constraints of the take-off and landing field construction

[0062] Based on the extracted geographic data of the pre-construction area of ​​the take-off and landing field, the technical feasibility of eVTOL take-off and landing field construction is analyzed, and the pre-construction area of ​​the take-off and landing field that meets the technical constraints of the take-off and landing field construction is screened; the technical constraints of the take-off and landing field construction include: take-off and landing field terrain constraints, take-off and landing field airspace restriction range, take-off and landing field noise constraints, take-off and landing field power grid capacity constraints, and take-off and landing field communication, navigation and surveillance system signal strength constraints.

[0063] The landing field terrain constraint in the landing field construction technical constraint is based on the landing field construction standards issued by EASA and FAA, which is to reduce the available area in the landing field pre-construction area to As i At least set L × L , L is the side length of the landing field apron; at the same time, the obstacle height around the landing field pre-construction area is Oh i Cannot exceed the total height of the take-off and landing apron H + H 1 , H is the vertical take-off height of the eVTOL, H 1 is the height at which the eVTOL surpasses obstacles within 100m during the climb phase after vertical takeoff; the expressions are:

[0064] As i ≥ L × L (1);

[0065] Oh i ≤ H + H 1 (2).

[0066] For example: This embodiment selects the side length of one of the take-off and landing fields L 30m; vertical take-off and landing height H 30.5m; after vertical takeoff, during the climb phase, the height of obstacles within 100m is exceeded H 1 Therefore, the available area of ​​the landing field pre-construction area is As i Should be at least 900m 2 , obstacle height around the take-off and landing field pre-construction area Oh i It cannot exceed 43m from the take-off and landing apron.

[0067] According to formula (1) and formula (2), the available area of ​​the pre-construction area of ​​the take-off and landing field will not be satisfied. As i and the height of obstacles around the pre-construction area of ​​the take-off and landing field Oh i Requested area exclusion.

[0068] The restricted airspace range of the take-off and landing field in the technical constraints for take-off and landing field construction does not overlap with the publicly released airspace restricted areas and restricted areas. This embodiment obtains the airspace restricted areas and restricted areas released by the Civil Aviation Administration of China and excludes the corresponding areas.

[0069] The landing field noise constraint in the landing field construction technical constraint conditions is: the actual perceived noise level in the landing field pre-construction area L 1 No higher than the noise emission standard St noise , the expression is:

[0070] L 1 ≤ St noise (3).

[0071] This example uses the Joby S4 electric vertical take-off and landing aircraft to carry out the landing field noise constraint assessment. d 2 =11.6m, the noise generated by the electric vertical take-off and landing aircraft is L max =54dB, the distance between noise-sensitive facilities and the pre-construction area of ​​the take-off and landing field isd 1 。 Will d 1 、L max 、d 2 Substitute into the formula L max - 20log 10 ( d 2 / d 1 ), solve the noise level at the noise-sensitive facilities. The noise level at the noise-sensitive facilities is compared with the ambient noise. L en Compare to get the actual perceived noise level L 1 : L 1 =max{ L max - 20log 10 ( d 2 / d 1 ), L en According to formula (3), if the actual perceived noise level L 1 Higher than noise emission standards St noise , then the take-off and landing field must be abandoned.

[0072] The grid capacity constraint of the take-off and landing field in the technical constraints of the take-off and landing field construction is: the take-off and landing field pre-construction area i Available grid capacity P i ag Greater than or equal to the charging power of a single eVTOL P 1 , the expression is:

[0073] P i ag ≥ P 1 (4);

[0074] Landing and take-off field pre-construction area i Available grid capacity P i ag The calculation formula is:

[0075] Pi ag = (1- K ) × P L - P u (5);

[0076] P L = P G - P u (6);

[0077] Where, P L is the remaining grid capacity; P G is the total capacity of the power grid; P u is the used grid capacity; K It is the percentage of reserved grid capacity to remaining grid capacity.

[0078] To ensure the safe load of the power grid, 5% of the remaining power grid capacity should be reserved. P L , then from formula (5) we get: P i ag =0.95 P L - P u .

[0079] The remaining available grid capacity in the pre-construction area of ​​the take-off and landing field should be sufficient for charging at least one eVTOL. The charging power of a single eVTOL is known. P 1 If the power is 300kW, then formula (4) gives: P i ag ≥300.

[0080] The signal strength constraint of the communication, navigation and surveillance system of the take-off and landing field in the technical constraints of the take-off and landing field construction is: obtain the daily received signal strength in the pre-construction area of ​​the take-off and landing field Sr i Minimum value, and the receiving signal strength standard of the communication, navigation and monitoring system of the take-off and landing field St signal By comparison, the daily received signal strength at the take-off and landing field pre-construction area is greater than or equal to the received signal strength standard of the communication, navigation and surveillance system of the take-off and landing field signal , the expression is:

[0081] Sr i ≥St signal (7).

[0082] This embodiment obtains the daily received signal strength at the pre-construction area of ​​the take-off and landing field Sr i Minimum value and received signal strength standard St signal Compare. According to existing standards, the received signal strength standard of the known communication navigation surveillance system is St signal =33dBm. If the daily received signal strength Sr i The minimum value is lower than the received signal strength standard St signal ,Right now Sr i If the noise level is less than 33 dBm, the landing field should be excluded according to formula (7).

[0083] Step 3: Determine the passenger flow attraction factor in the pre-construction area

[0084] Based on the distance from the high-traffic area to the pre-construction area that meets the technical constraints of the take-off and landing field construction St kc , determine the passenger flow attraction factor of the pre-construction area in high-traffic areas Ed i :

[0085] (16).

[0086] Step 4: Calculate ride demand

[0087] The riding demand is calculated based on the traffic passenger flow, business office population, road congestion, scenic area passenger flow and passenger attraction factor in the pre-construction area that meets the technical constraints of the take-off and landing field construction; the riding demand includes: the total commuting demand in the business office area, the total tourism demand in the scenic area, the total travel demand and road traffic congestion in the pre-construction area that meets the technical constraints of the take-off and landing field construction.

[0088] The total commuting demand of the business office area in the pre-construction area that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i and the number of business office population W i , calculate the commuting demand of business office areas A i , and then calculate the total commuting demand of the business office area Atr i :

[0089] A i = W i × Cd i (8);

[0090] Atr i =∑ A i (9).

[0091] The total tourism demand of scenic spots in the pre-construction area that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Cd i and the flow of people in scenic spots Atr i Calculate the tourism demand for scenic spots B i , and then calculate the total tourism demand of the scenic area VP i :

[0092] B i = Td i × i (10);

[0093] VP i =∑ B i (11).

[0094] The total travel demand in the pre-construction area that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i Traffic passenger flow F i , calculate the travel demand of traffic C i , and then calculate the total travel demand T i :

[0095] C i = F i × Td i (12);

[0096] T i =∑ C i (13).

[0097] The traffic congestion situation of roads in the pre-construction area of ​​the take-off and landing field that meets the technical constraints of the take-off and landing field construction, and the average congestion coefficient is calculated using the congestion coefficient of each road section Atr i , the expression is as follows:

[0098] (14);

[0099] Where, Atr i For road sections i Road congestion coefficient; n is the total number of road sections in the pre-construction area; then the average congestion coefficient Aver i Compare to the smooth travel time obtained from the map software Cg i Multiply them to get the traffic congestion situation in the pre-construction area. Aver i :

[0100] Ub i = At i × At i (15).

[0101] The eVTOL ride demand obtained by calculating the raw data in Table 1 is shown in Table 2:

[0102] Table 2 Demand for eVTOL rides of various types

[0103] .

[0104] Step 5: Ride Demand Density Assessment

[0105] Based on the passenger demand, the passenger demand density is solved to evaluate whether the pre-construction area that meets the technical constraints of the take-off and landing field construction meets the demand density constraint; the hierarchical analysis method is used to obtain the weight of each passenger demand Aver ; Then, establish the riding demand density D i Calculation formula:

[0106] (17);

[0107] Where, Ub i is the total tourism demand of the scenic area; T i is the total travel demand for transportation; γ i is the total commuting demand for business office areas;Td i For road traffic congestion; Cd Td is the weight of the total tourism demand of the scenic spot to the total ride demand; At T is the weight of the total travel demand to the total ride demand; γ Cd The weight of the total commuting demand in the business office area to the total riding demand; γ At is the weight of road traffic congestion in the total ride demand; S The area of ​​the pre-construction area that meets the technical constraints of the take-off and landing field construction.

[0108] eVTOL ride demand density D i Should meet the riding demand density assessment standards γ demand , the expression is:

[0109] D i ≥ γ demand (18).

[0110] Evaluation criteria for known ridership demand density St demand = 1000, In this embodiment, according to formula (18), the riding demand density is obtained D i Greater than or equal to 1000.

[0111] The passenger demand density of the pre-construction areas of the 21 eVTOL take-off and landing sites in this embodiment is shown in Table 3.

[0112] Table 3 Passenger demand density in the pre-construction area of ​​the take-off and landing area

[0113] .

[0114] Step 6: Analysis of Transfer Convenience at Take-off and Landing Airports

[0115] The pre-construction area that meets the technical constraints of the take-off and landing field construction should meet the convenience of transfer at the take-off and landing field; the walking time from the pre-construction area of ​​the take-off and landing field to the surrounding traffic is introduced as St i , the walking time does not exceed the maximum acceptable walking time obtained from the survey St time , the expression is:

[0116] Wt i ≤ Sttime (19).

[0117] The time it takes to walk from the pre-construction area of ​​the take-off and landing field to the surrounding traffic in this embodiment Wt i Do not exceed the maximum acceptable walking time obtained from the survey St time 10 minutes, the walking time from the pre-construction area of ​​the take-off and landing field to the surrounding traffic Wt See Table 4. The pre-construction areas of the take-off and landing fields except P1, P4, P8, P18, and P19 all meet formula (19).

[0118] Table 4 Walking time from each eVTOL landing site pre-construction area to other transportation

[0119] .

[0120] Step 7: Build a take-off and landing network

[0121] Assess the risk value of all pre-construction areas that meet the transfer convenience of the take-off and landing area, the technical constraints of the take-off and landing area construction, and the density constraints of eVTOL passenger demand X , the pre-construction area i and pre-construction areas j Value at Risk X i and X j Substitute the following formula to calculate the simple correlation coefficient of any two landing field pre-construction areas: r ij :

[0122] (20);

[0123] Where, St ( X i , X j ) is the pre-construction area i and pre-construction areas j The covariance of the pre-construction area i and pre-construction areas j Value at Risk X i and X j Standard deviation of pre-construction area i and pre-construction areas j The partial rank correlation coefficient r ij,h for:

[0124] (twenty one);

[0125] Where, r ij,h Indicates pre-construction area i and pre-construction areas j In the control pre-construction area h The partial rank correlation coefficient after r ij Indicates pre-construction area i and pre-construction areas j The simple correlation coefficient of r ih and r jh Represents the pre-construction area i and pre-construction areas h , pre-construction area j and pre-construction areas h The simple correlation coefficient of .

[0126] The partial rank correlation coefficient r ij,h Greater than or equal to Pearson correlation coefficient test standard Wti p In the landing field pre-construction area, a landing field is established and a landing field network is constructed. The expression is:

[0127] r ij,h ≥ Cov p (twenty two) .

[0128] Known Pearson correlation coefficient test standard St p is 0.05. In this embodiment, the partial rank correlation coefficient of all landing field pre-construction areas in the landing field network is r ij,h All satisfy formula (22).

[0129] In this embodiment, the partial rank correlation coefficients of all pre-construction areas are compared with the Pearson correlation coefficient test standard, and finally eVTOL landing sites are established at P2, P5, P9, P13, P14, and P17 in the pre-construction areas. The longitude and latitude coordinates of the eVTOL landing sites are shown in Table 5. The locations of the eVTOL landing sites and the landing site network they constitute are shown in Table 5. St .

[0130] Table 5 Latitude and longitude coordinates of eVTOL take-off and landing sites

[0131]

[0132] Step 8: Evaluate the traffic characteristics of the take-off and landing network

[0133] Calculate the total degree value of each eVTOL landing site based on the landing site network St The total degree value refers to the total number of edges connected to the take-off and landing field, of which the number of edges pointing to the eVTOL take-off and landing field is the in-degree Figure 2 , the number of edges sent out from the eVTOL take-off and landing site is the out-degree deg , the total degree value is equal to the in-degree indeg and outdegree outdeg The sum of is expressed as follows:

[0134] indeg = outdeg + deg indeg outdeg (twenty three).

[0135] According to the total degree value of each eVTOL take-off and landing site, the take-off and landing site with a larger total degree value has a greater impact on the overall eVTOL take-off and landing site network.

[0136] The total degree values ​​of each eVTOL take-off and landing field in this embodiment are shown in Table 6.

[0137] Table 6 Total value of eVTOL take-off and landing field

[0138] .

[0139] Based on the total degree value of each eVTOL landing site, we evaluate the eVTOL landing sites that play a key role in the overall eVTOL landing site network. The larger the total degree value, the greater the impact of the landing site on the overall eVTOL landing site network. Table 6 shows that eVTOL landing site P13 plays the most critical role in the overall landing site network; eVTOL landing site P17 has a less significant impact on the overall landing site network.

[0140] When constructing and evaluating a landing site network, the priority should be to select landing sites that meet both the technical constraints for landing site construction and the passenger demand density standard. 1. Assess the technical feasibility of landing site construction. Any landing sites that do not meet the technical constraints should be eliminated. 2. Evaluate passenger demand density from the perspective of passenger demand. If the calculated passenger demand density does not meet the passenger demand density standard, the landing site should be eliminated. 3. Evaluate landing site feasibility from the perspective of transfer convenience. Any landing site whose walking time from surrounding transportation hubs exceeds the maximum acceptable walking time should be eliminated. 4. Calculate the partial rank correlation coefficient for landing sites that meet the technical constraints for landing site construction and the passenger demand standard. Eliminate any landing sites that do not meet the partial rank correlation coefficient standard. 5. Construct a landing site network using landing sites that simultaneously meet the technical constraints for landing site construction, passenger demand density, and partial rank correlation coefficient standards. 6. Based on the constructed landing site network, calculate the total degree of each landing site in the network. The total degree value of each landing field is used to evaluate the landing field that plays a key role in the overall landing field network. The landing field with a larger total degree value has a greater impact on the overall landing field network.

Claims

1. A method for constructing and evaluating an eVTOL take-off and landing site network in an urban environment, characterized in that: Here are the steps:

1. Extraction of geographic data of the pre-construction area of ​​the take-off and landing field; 2. Screening pre-construction areas that meet the technical constraints for landing and take-off site construction; 3. Determine the passenger flow attraction factors in the pre-construction area; 4. Calculation of Ride Demand Calculate the demand for rides based on the passenger flow in the pre-construction area, the number of business office residents, the road congestion coefficient, the flow of people in scenic spots, and the passenger attraction factor in the pre-construction area; V. Ride Demand Density Assessment Solve the riding demand density based on the riding demand volume, and the riding demand density should meet the riding demand density assessment standard; VI. Analysis of Transfer Convenience at Take-off and Landing Airports Introduce walking time from the pre-construction area of ​​the landing field to surrounding traffic, and the walking time shall not exceed the maximum acceptable walking time surveyed; 7. Build a take-off and landing field network Calculate the simple correlation coefficient and partial rank correlation coefficient between any two pre-construction areas; establish landing pads and build a landing pad network in the pre-construction areas where the partial rank correlation coefficient is greater than or equal to the correlation coefficient test standard; 8. Evaluating the Traffic Characteristics of the Landing and Take-off Network The total degree value of each landing field is calculated based on the landing field network; the landing field with a larger total degree value has a greater impact on the overall eVTOL landing field network.

2. The method for constructing and evaluating an eVTOL take-off and landing site network in an urban environment according to claim 1, characterized in that: In step 2, the technical constraints for the construction of the landing pad include: landing pad terrain constraints, landing pad airspace restrictions, landing pad noise constraints, landing pad power grid capacity constraints, and landing pad communication, navigation, and surveillance system signal strength constraints. The landing field terrain constraint in the landing field construction technical constraint condition is based on the landing field construction standards issued by EASA and FAA. As i At least set L × L , L is the side length of the apron of the take-off and landing field; At the same time, the obstacle height around the pre-construction area of ​​the take-off and landing field Oh i Cannot exceed the total height of the take-off and landing apron H + H 1 , H is the vertical take-off height of the eVTOL, H 1 is the height at which the eVTOL surpasses obstacles within 100m during the climb phase after vertical takeoff; the expressions are: The restricted airspace range of the take-off and landing field in the technical constraints of the take-off and landing field construction does not overlap with the publicly released airspace restricted areas and restricted areas; The landing field noise constraint in the landing field construction technical constraint conditions is: the actual perceived noise level in the landing field pre-construction area L 1 No higher than the noise emission standard St noise , the expression is: The grid capacity constraint of the landing field in the technical constraint conditions of the landing field construction is: the landing field pre-construction area i Available grid capacity P i ag Greater than or equal to the charging power of a single eVTOL P 1 , the expression is: Where, the take-off and landing field pre-construction area i Available grid capacity P i ag The calculation formula is: Where, P L is the remaining grid capacity; P G is the total capacity of the power grid; P u is the used grid capacity; K The percentage of reserved grid capacity to remaining grid capacity; The signal strength constraint of the communication, navigation and monitoring system of the take-off and landing field in the technical constraint conditions of the take-off and landing field construction is as follows: obtain the daily received signal strength at the pre-construction area of ​​the take-off and landing field Sr i Minimum value, and the receiving signal strength standard of the communication, navigation and monitoring system of the take-off and landing field St signal By comparison, the daily received signal strength at the take-off and landing field pre-construction area is greater than or equal to the received signal strength standard of the communication, navigation and surveillance system of the take-off and landing field. St signal , the expression is:

3. The method for constructing and evaluating an eVTOL take-off and landing site network in an urban environment according to claim 1, characterized in that: The commuting demand of the business office area in the pre-construction area of ​​the take-off and landing field that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i and the number of business office population W i , calculate the commuting demand of business office areas A i , and then calculate the total commuting demand of the business office area in the pre-construction area that meets the technical constraints of the take-off and landing field construction Cd i : The tourism demand for scenic spots in the pre-construction area of ​​the take-off and landing field that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the pre-construction area. Atr i and the flow of people in scenic spots VP i Calculate the tourism demand for scenic spots B i , and then calculate the total tourism demand of scenic spots in the pre-construction area that meets the technical constraints of the take-off and landing field construction Td i : The travel demand in the pre-construction area of ​​the take-off and landing field that meets the technical constraints of the take-off and landing field construction is calculated based on the passenger flow attraction factor of the take-off and landing field. Atr i Traffic passenger flow F i , calculate the travel demand of traffic C i , and then calculate the total travel demand of the traffic in the pre-construction area that meets the technical constraints of the take-off and landing field construction T i : The traffic congestion situation of roads in the pre-construction area that meets the technical constraints of the take-off and landing field construction, and the average congestion coefficient is calculated using the congestion coefficient of each road section Aver i , the expression is as follows: （14）； Where, Cg i For road sections i Road congestion coefficient; n is the total number of road sections in the pre-construction area; Then the average congestion coefficient Aver i Compare to the smooth travel time obtained from the map software Ub i Multiply them to get the traffic congestion situation in the pre-construction area. At i ：

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