An Evaluation Method for Grid-based Airspace Complexity Based on Aircraft Interaction Relationships

Abstract

An airspace complexity grid evaluation method based on the interaction relationship of aircraft. It includes steps such as loading aircraft operation trajectory data, setting the time-domain and airspace parameters to be measured, performing grid processing on the airspace to be measured, performing fragmentation processing on the time-domain to be measured, screening the set of aircraft passing through a certain grid in a certain period, judging whether there is time overlap among the aircraft in the aircraft set, judging whether spatial interaction occurs among the aircraft, calculating the total interaction duration of the aircraft in the grid in this period, calculating the operation time of the aircraft in the grid in this period, calculating the grid interaction index of the grid in this period, calculating the airspace interaction index of this period, calculating the airspace complexity of the airspace to be measured in this period, calculating the average complexity of the time-domain and airspace to be measured, calculating the spatial balance degree of the airspace complexity, and calculating the time balance degree of the airspace complexity. The present invention is simple and easy to use, not affected by human factors, and can realize the rapid quantitative evaluation of air traffic complexity.

Description

Technical Field

[0001] The present invention belongs to the technical field of air traffic management, and particularly relates to a grid-based evaluation method for airspace complexity based on the interaction relationship of aircraft. Background Art

[0002] The evaluation of air traffic complexity is the basis for the evaluation of air traffic control workload, and is of great significance to the safety and efficiency of air traffic operation. The current air traffic complexity evaluation methods mainly include the evaluation based on traffic density and the evaluation based on dynamic density. Among them, the evaluation method based on traffic density cannot consider the different degrees of complexity caused by the differences in the operation states of aircraft. The evaluation method based on dynamic density requires artificial weighting for various complexity factors and is easily affected by human factors. Moreover, both methods are difficult to process large-scale historical data, which is not conducive to using large-range and long-time historical data as calculation samples to reflect the long-term operation state of a certain airspace and improve the accuracy and usability of the calculation results. Summary of the Invention

[0003] In order to solve the above problems, the purpose of the present invention is to provide a grid-based evaluation method for airspace complexity based on the interaction relationship of aircraft.

[0004] In order to achieve the above purpose, the grid-based evaluation method for airspace complexity based on the interaction relationship of aircraft provided by the present invention includes the following steps carried out in sequence:

[0005] Step 1) Load aircraft operation trajectory data: Load the actual operation data of aircraft from the air traffic management data storage system, extract the data including the departure airport, arrival airport, aircraft type, actual departure time, actual arrival time, and the time stamps, longitudes, latitudes, altitudes, speeds, headings, and climb rates of the actual flight paths of the aircraft, and then store them in the database;

[0006] Step 2) Set the time-domain and airspace parameters to be measured: Set the start and end times of the time-domain to be measured; set the longitude and latitude coordinates of each boundary point of the airspace to be measured and the altitude range allowed for aircraft operation within the airspace;

[0007] Step 3) Perform grid processing on the airspace to be measured: According to the longitude and latitude coordinates of each boundary point of the airspace to be measured and the altitude range allowed for aircraft operation within the airspace set in Step 2), use a plurality of densely paved cuboid-shaped grids with a length and width of L S and a height of H S to divide the above-mentioned airspace to be measured to obtain a plurality of grids, and determine the boundary coordinate data of each grid;

[0008] Step 4) Perform fragmentation processing on the time-domain to be measured: Divide the above-mentioned time-domain to be measured in units of a time period T S to obtain a plurality of time periods;

[0009] Step 5) Screening the set of aircraft passing through a certain grid during a certain period: Select a certain grid obtained by partitioning in Steps 3) and 4). According to the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in Step 1), screen out the aircraft passing through this grid during this period as the aircraft set; the time for the aircraft to enter and leave the grid is in minutes. Subtract the buffer time Δt1 from the moment when the aircraft enters the grid, and add the buffer time Δt2 to the moment when the aircraft leaves the grid.

[0010] Step 6) Judging whether there is time overlap among the aircraft in the aircraft set: Traverse the aircraft set obtained in Step 5), and select any two aircraft as an aircraft group one by one. Judge whether there is cross-overlap in the passing time of each aircraft group. If so, set the potential interaction relationship value of this aircraft group for this grid to 1, otherwise set it to 0.

[0011] Step 7) Judging whether there is spatial interaction among the aircraft: Traverse the aircraft groups with a potential interaction relationship value of 1 obtained in Step 6). According to the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in Step 1) and the boundary coordinate data of the grid determined in Step 3), judge whether there is horizontal interaction, vertical interaction, and speed interaction among the aircraft in each aircraft group minute by minute; if there is horizontal interaction, set the horizontal interaction value of this aircraft group at this moment to 1, otherwise set it to 0; if there is vertical interaction, set the vertical interaction value of this aircraft group at this moment to 1, otherwise set it to 0; if there is speed interaction, set the speed interaction value of this aircraft group at this moment to 1, otherwise set it to 0.

[0012] Step 8) Calculating the total interaction duration of the aircraft in this grid during this period: Traverse the horizontal interaction values, vertical interaction values, and speed interaction values of each aircraft group at each moment obtained in Step 7). After summing them respectively, the horizontal interaction duration, vertical interaction duration, and speed interaction duration of this grid during this period are obtained; then add the horizontal interaction duration, vertical interaction duration, and speed interaction duration to get the total interaction duration of the aircraft in this grid during this period.

[0013] Step 9) Calculating the operation time of the aircraft in this grid during this period: According to the aircraft set passing through this grid during this period obtained in Step 5), the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in Step 1), and the boundary coordinate data of the grid determined in Step 3), retrieve the moments when each aircraft in the aircraft set enters and leaves this grid, and calculate the duration of each aircraft running in this grid; add the durations of each aircraft running in the aircraft set to get the operation time of the aircraft in this grid during this period.

[0014] Step 10) Calculate the grid interaction index of this grid during this period: Divide the total interaction duration of the aircraft in this grid during this period obtained in Step 8) by the operation time of the aircraft in this grid during this period obtained in Step 9), and the grid interaction index of this grid during this period can be obtained;

[0015] Step 11) Calculate the airspace interaction index of this period: According to the calculation methods of the total interaction duration of the aircraft in a certain grid during a certain period obtained in Step 8) and the operation time of the aircraft obtained in Step 9), calculate the total interaction duration and operation time of the aircraft in each grid during this period, and sum up the total interaction duration and operation time of the aircraft in each grid to obtain the airspace interaction duration and the airspace operation time of this period; Then divide the above-mentioned airspace interaction duration of this period by the airspace operation time of this period, and the airspace interaction index of this period can be obtained;

[0016] Step 12) Calculate the airspace complexity of the airspace to be measured during this period: According to the calculation method of the grid interaction index of a certain grid during a certain period obtained in Step 10), calculate and sum up the grid interaction indexes of each grid during this period; Then multiply the summation result by the airspace interaction index of this period obtained in Step 11), and the airspace complexity of this period can be obtained;

[0017] Step 13) Calculate the average complexity of the time domain - airspace to be measured: According to the time period obtained in Step 4) and the calculation method of the airspace complexity described in Step 12), calculate the airspace complexity of each period respectively, and then find the average value, and the average complexity of the airspace to be measured can be obtained;

[0018] Step 14) Calculate the spatial balance degree of the airspace complexity: According to the calculation method of the grid interaction index of a certain grid during a certain period described in Step 10), and the start and end times of the time domain to be measured set in Step 2), calculate the grid interaction indexes of each grid in each period within the time domain to be measured, and calculate the variance of the grid interaction indexes of each grid within each period. Subsequently, take the maximum value of the variances of each period, which is the spatial balance degree of the airspace complexity within the time domain - airspace to be measured;

[0019] Step 15) Calculate the temporal balance degree of the airspace complexity: According to the calculation method of the airspace complexity of a certain period described in Step 12), calculate the airspace complexity of each period within the time domain to be measured respectively, and calculate the variance of the airspace complexity of each period, which is the temporal balance degree of the airspace complexity within the time domain - airspace to be measured.

[0020] In step 7), the method for determining whether there is horizontal interaction between aircraft is as follows: traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time periods of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight paths of the aircraft described in step 1), retrieve the horizontal headings of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their headings are represented by H t (a, k) and H t (b, k) respectively; let the heading angle threshold be H0. If the heading angle is greater than or equal to the heading angle threshold, that is, |H t (a, k) - H t (b, k)| ≥ H0, it is considered that there is horizontal interaction between the two aircraft at time t, that is, the horizontal interaction value corresponding to the aircraft group at time t is 1.

[0021] In step 7), the method for determining whether there is vertical interaction between aircraft is as follows: traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time periods of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight paths of the aircraft described in step 1), retrieve the climb rates of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their climb rates are represented by V t (a, k) and V t (b, k) respectively; the positive threshold of the climb rate of the aircraft is represented by V0, and the negative threshold is represented by -V0. If the climb rate of the aircraft is greater than or equal to the positive climb rate threshold V0, it is considered that the aircraft is in a climbing state; if the climb rate is less than or equal to the negative climb rate threshold -V0, it is considered that the aircraft is in a descending state; otherwise, it is considered that the aircraft is in a level flight state. Detect the vertical flight states of the two aircraft. If the vertical flight states are different, it is considered that there is vertical interaction between the two aircraft, that is, the vertical interaction value corresponding to the aircraft group at time t is 1.

[0022] In step 7), the method for determining whether there is speed interaction between aircraft is as follows: traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time periods of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight paths of the aircraft described in step 1), retrieve the speeds of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their speeds are represented by S t (a, k) and S t (b, k) respectively; the speed difference threshold between the two aircraft is represented by S0. If the speed difference between the two aircraft is greater than or equal to the speed difference threshold S0, that is, |S t (a, k) - S t (b, k)| ≥ S0, it is considered that there is speed interaction between the two aircraft at time t, that is, the speed interaction value corresponding to the aircraft group at time t is 1.

[0023] In step 10), the method for calculating the grid interaction index of a certain grid in a certain time period is as follows: Assume that in step 3), the time period is divided into m time periods, the airspace is divided into n grids, and the horizontal, vertical, and speed interaction durations of each aircraft group with the j-th grid at each moment within the i-th time period obtained in step 8) are summed respectively, which are the horizontal, vertical, and speed interaction times of the grid within this time period, and are respectively represented by ; The total interaction duration of aircraft within the grid is represented by ; it is the sum of the horizontal, vertical, and speed interaction times of the grid, that is The operation time of aircraft within the grid in this time period is represented by ; the grid interaction index is represented by and is calculated by dividing the interaction duration of aircraft within the grid by the operation time of aircraft within the grid, that is

[0024] In step 11), the method for calculating the airspace interaction index of a certain time period is as follows: Assume that in step 3), the time domain is divided into m time periods and the airspace is divided into n grids, then the aircraft interaction duration of the j-th grid within the i-th time period is The operation time of aircraft of the j-th grid within the i-th time period is The airspace interaction index AD of this time period i is the sum of the aircraft interaction durations of each grid in this time period divided by the sum of the operation times of aircraft within each grid, that is

[0025] In step 12), the method for calculating the airspace complexity of a certain time period is as follows: Assume that in step 3), the time domain is divided into m time periods and the airspace is divided into n grids, then the grid interaction index of the j-th grid within the i-th time period is The airspace interaction index of this time period is AD i ; The airspace complexity C of this time period i is the sum of the grid interaction indices of each grid in this time period multiplied by the airspace interaction index of this time period, that is

[0026] In step 13), the method for calculating the average complexity of the time domain-airspace to be measured is as follows: Assume that in step 3), the time domain is divided into m time periods and the airspace is divided into n grids, and the airspace complexity of the i-th time period is C i ; then the average complexity of this time domain-airspace is the average value of the airspace complexities of each time period, that is

[0027] In step 14), the method for calculating the spatial balance degree of the airspace complexity is as follows: Assume that in step 3), the time domain is divided into m time periods and the airspace is divided into n grids, and the grid interaction index of the j-th grid within the i-th time period is The average value of the interaction indices of each grid during this period The variance of the interaction indices of each grid They can be calculated separately. The spatial balance degree of the spatial complexity within the to-be-measured time domain - spatial domain is the maximum value of the variances of each period, that is, C A_S = max 1≤i≤m SI D i .

[0028] In step 15), the calculation method of the time balance degree of the spatial complexity is as follows: Assume that in step 3), the time domain is divided into m periods, the spatial domain is divided into n grids, and the spatial complexity of the i-th period is C i ; the average complexity within this time domain - spatial domain is C; then the time balance degree value of the spatial complexity within the to-be-measured time domain - spatial domain is the variance of the spatial complexities of each period, that is

[0029] The beneficial effects of the present invention are as follows: The evaluation method is simple and easy to use, not affected by human factors, and can achieve rapid quantitative evaluation of air traffic complexity. After accessing the historical flight track data of aircraft and the to-be-measured time domain - spatial domain data, based on the flight interaction relationships of each aircraft within the to-be-measured airspace during a certain period, the air traffic complexity of the to-be-measured airspace is evaluated. Without manual intervention and with reliable performance, it is a method for accurately and rapidly quantifying and evaluating the complexity of traffic situations in the airspace through large-scale historical flight track data. It can make up for the deficiencies of current technologies and methods and provide a basis for the construction of a new generation of air traffic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flowchart of the grid-based evaluation method for airspace complexity based on aircraft interaction relationships provided by the present invention;

[0031] Figure 2 is a schematic diagram of the grid division of the to-be-measured airspace in an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of the vertical direction of the aircraft operation state in an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of the horizontal direction of the aircraft operation state in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be further described below with reference to the drawings and embodiments.

[0035] As Figure 1 shown, the grid-based evaluation method for airspace complexity based on aircraft interaction relationships provided by the present invention includes the following steps carried out in sequence:

[0036] Step 1) Load aircraft flight trajectory data: Load the actual flight data of the aircraft from the air traffic management data storage system, extract data including the departure airport, arrival airport, aircraft type, actual departure time, actual arrival time, and the timestamps, longitudes, latitudes, altitudes, speeds, headings, and climb rates of the actual flight path of the aircraft, and then store them in the database;

[0037] Step 2) Set the time-domain and airspace parameters to be measured: Set the start and end times of the time domain to be measured; Set the longitude and latitude coordinates of each boundary point of the airspace to be measured and the altitude range within which the aircraft is allowed to operate in the airspace;

[0038] Step 3) Perform rasterization processing on the airspace to be measured: According to the longitude and latitude coordinates of each boundary point of the airspace to be measured and the altitude range within which the aircraft is allowed to operate in the airspace set in Step 2), use multiple densely paved cuboid rasters with a length and width of L S and a height of H S to divide the above-mentioned airspace to be measured to obtain multiple rasters, and determine the boundary coordinate data of each raster;

[0039] Step 4) Perform fragmentation processing on the time domain to be measured: Divide the above-mentioned time domain to be measured in units of time period T S to obtain multiple time periods;

[0040] Step 5) Screen the set of aircraft passing through a certain raster in a certain time period: Select a certain raster in a certain time period obtained by dividing in Step 3) and Step 4), and screen out the aircraft passing through this raster within this time period as the aircraft set according to the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in Step 1); The time when the aircraft enters and leaves the raster is in minutes. Subtract the buffer time Δt1 from the moment when the aircraft enters the raster, and add the buffer time Δt2 to the moment when the aircraft leaves the raster;

[0041] The method for setting the buffer time when the aircraft enters and leaves the raster is as follows: Since in actual operation, the time when the aircraft enters or leaves a certain raster may not be an integer minute moment and may be a certain second within that minute, in order to facilitate the subsequent judgment in Step 6) as to whether there is a time overlap among the aircraft, the time when it enters and leaves the raster is rounded to the nearest minute. The time when it enters the raster is rounded up, and the time when it leaves the raster is rounded down; And since when the aircraft enters and leaves the raster, its operation information will be handed over between the two rasters, and the air traffic controller needs to adjust and process the existing aircraft in the airspace based on this information, within a short period of time before the aircraft enters a certain raster and after it leaves a certain raster, its influence on this raster still exists; For the above reasons, subtract the buffer time Δt1 from the moment when the aircraft enters the raster, and add the buffer time Δt2 to the moment when the aircraft leaves the raster, so as to facilitate measuring the total influence time of a certain aircraft on a certain raster.

[0042] Step 6) Determine whether there is time overlap among the aircraft in the aircraft set: Traverse the aircraft set obtained in step 5), select any two aircraft as an aircraft group one by one, and determine whether there is cross-overlap in the passing times of each aircraft group. If there is, set the potential interaction relationship value of this aircraft group for this grid to 1; otherwise, set it to 0.

[0043] Step 7) Determine whether there is spatial interaction among the aircraft: Traverse the aircraft groups with a potential interaction relationship value of 1 obtained in step 6), and based on the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in step 1) and the boundary coordinate data of the grid determined in step 3), determine whether there is horizontal interaction, vertical interaction, or speed interaction among the aircraft in each aircraft group minute by minute. If there is horizontal interaction, set the horizontal interaction value of this aircraft group at this moment to 1; otherwise, set it to 0. If there is vertical interaction, set the vertical interaction value of this aircraft group at this moment to 1; otherwise, set it to 0. If there is speed interaction, set the speed interaction value of this aircraft group at this moment to 1; otherwise, set it to 0.

[0044] The method for determining whether there is horizontal interaction among the aircraft is as follows: Traverse the aircraft groups with time overlap obtained in step 6). For the overlapping period of the two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft described in step 1), and retrieve the horizontal headings of each aircraft minute by minute. At time t, aircraft a and b are both in grid k, and their headings are represented by H t (a, k), H t (b, k); Let the heading angle threshold be H0. If the heading angle is greater than or equal to the heading angle threshold, that is, |H t (a, k) - H t (b, k)| ≥ H0, then it is considered that there is horizontal interaction between the two aircraft at time t, that is, the horizontal interaction value corresponding to this aircraft group at time t is 1.

[0045] The method for determining whether there is vertical interaction among the aircraft is as follows: Traverse the aircraft groups with time overlap obtained in step 6). For the overlapping period of the two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft described in step 1), and retrieve the climb rates of each aircraft minute by minute. At time t, aircraft a and b are both in grid k, and their climb rates are represented by V t (a, k), V t(b, k) indicates that the positive threshold of the climb rate of the aircraft is represented by V0, and the negative threshold is represented by -V0. If the climb rate of the aircraft is greater than or equal to the positive climb rate threshold V0, it is considered that the aircraft is in a climbing state; if the climb rate is less than or equal to the negative climb rate threshold -V0, it is considered that the aircraft is in a descending state; otherwise, it is considered that the aircraft is in a level flight state. Detect the vertical flight states of two aircraft. If the vertical flight states are different, it is considered that there is a vertical interaction between the two aircraft, that is, the vertical interaction value corresponding to the aircraft group at time t is 1.

[0046] The method for determining whether there is a speed interaction between aircraft is as follows: Traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time period of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft described in step 1), and retrieve the speeds of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their speeds are represented by S t (a, k) and S t (b, k) respectively; the speed difference threshold between the two aircraft is represented by S0. If the speed difference between the two aircraft is greater than or equal to the speed difference threshold S0, that is, |S t (a, k) - S t (b, k)| ≥ S0, it is considered that there is a speed interaction between the two aircraft at time t, that is, the speed interaction value corresponding to the aircraft group at time t is 1.

[0047] Step 8) Calculate the total interaction duration of the aircraft in this grid during this period: Traverse the horizontal interaction values, vertical interaction values, and speed interaction values of each aircraft group at each moment obtained in step 7), and after summing them respectively, the horizontal interaction duration, vertical interaction duration, and speed interaction duration of this grid during this period are obtained; then add the horizontal interaction duration, vertical interaction duration, and speed interaction duration to obtain the total interaction duration of the aircraft in this grid during this period;

[0048] Step 9) Calculate the operation time of the aircraft in this grid during this period: According to the aircraft set passing through this grid during this period obtained in step 5), the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in step 1), and the grid boundary coordinate data determined in step 3), retrieve the moments when each aircraft in the aircraft set enters and leaves this grid, and calculate the duration of each aircraft running in this grid; add the durations of each aircraft running in the aircraft set to obtain the operation time of the aircraft in this grid during this period;

[0049] Step 10) Calculate the grid interaction index of this grid during this period: Divide the total interaction duration of the aircraft in this grid during this period obtained in step 8) by the operation time of the aircraft in this grid during this period obtained in step 9), and the grid interaction index of this grid during this period is obtained;

[0050] The calculation method of the grid interaction index of a certain grid in a certain time period is as follows: Assume that in step 3), the time period is divided into m time sub-periods, the airspace is divided into n grids, and the horizontal, vertical, and speed interaction durations of each aircraft group with the j-th grid at each moment within the i-th time sub-period obtained in step 8) are summed respectively, which are the horizontal, vertical, and speed interaction times of the grid within this time period, and are represented by respectively; the total interaction duration of aircraft within the grid is represented by which is the sum of the horizontal, vertical, and speed interaction times of the grid, that is The operation time of aircraft within the grid in this time period is represented by respectively, and the grid interaction index is represented by It is calculated by dividing the interaction duration of aircraft within the grid by the operation time of aircraft within the grid, that is

[0051] Step 11) Calculate the airspace interaction index of this time period: According to the calculation methods of the total interaction duration of aircraft within a certain grid in a certain time period obtained in step 8) and the operation time of aircraft obtained in step 9), calculate the total interaction duration and operation time of aircraft for each grid within this time period, and sum the total interaction duration and operation time of aircraft for each grid to obtain the airspace interaction duration and the airspace operation time of this time period; then divide the above-mentioned airspace interaction duration of this time period by the airspace operation time of this time period to obtain the airspace interaction index of this time period;

[0052] The calculation method of the airspace interaction index of a certain time period is as follows: Assume that in step 3), the time domain is divided into m time sub-periods, and the airspace is divided into n grids, then the aircraft interaction duration of the j-th grid within the i-th time sub-period is The operation time of aircraft of the j-th grid within the i-th time sub-period is The airspace interaction index AD of this time period i is the sum of the aircraft interaction durations of each grid within this time period divided by the sum of the operation times of aircraft within each grid, that is

[0053] Step 12) Calculate the airspace complexity of the airspace to be measured in this time period: According to the calculation method of the grid interaction index of a certain grid in a certain time period obtained in step 10), calculate the grid interaction indices of each grid within this time period and sum them; then multiply the summation result by the airspace interaction index of this time period obtained in step 11) to obtain the airspace complexity of this time period;

[0054] The calculation method of the airspace complexity of a certain time period is as follows: Assume that in step 3), the time domain is divided into m time sub-periods, and the airspace is divided into n grids, then the grid interaction index of the j-th grid within the i-th time sub-period is The airspace interaction index of this time period is AD i ; the airspace complexity C of this time periodi The sum of the grid interaction indices of each grid during this period is multiplied by the airspace interaction index of this period, that is

[0055] Step 13) Calculate the average complexity of the time domain - airspace to be measured: According to the periods obtained in Step 4) and the airspace complexity calculation method described in Step 12), calculate the airspace complexity of each period respectively, and then calculate the average value, that is, the average complexity of the airspace to be measured is obtained;

[0056] The calculation method of the average complexity of the time domain - airspace to be measured is: Assume that in Step 3), the time domain is divided into m periods, the airspace is divided into n grids, and the airspace complexity of the i - th period is C i ; then the average complexity of this time domain - airspace is the average value of the airspace complexities of each period, that is

[0057] Step 14) Calculate the spatial equilibrium degree of airspace complexity: According to the calculation method of the grid interaction index of a certain grid in a certain period described in Step 10), and the start and end times of the time domain to be measured set in Step 2), calculate the grid interaction indices of each grid in each period within the time domain to be measured, and calculate the variance of the grid interaction indices of each grid within each period. Subsequently, take the maximum value of the variances of each period, which is the spatial equilibrium degree of airspace complexity within the time domain - airspace to be measured; the higher this value, the greater the difference in the grid interaction indices of each grid within the time domain - airspace to be measured, and the weaker the spatial equilibrium degree;

[0058] The calculation method of the spatial equilibrium degree of airspace complexity is: Assume that in Step 3), the time domain is divided into m periods, the airspace is divided into n grids, and the grid interaction index of the j - th grid within the i - th period is Then the average value of the grid interaction indices of each grid in this period The variance of the grid interaction indices of each grid can be calculated respectively, and the spatial equilibrium degree of airspace complexity within the time domain - airspace to be measured is the maximum value of the variances of each period, that is C A_s =max 1≤i≤m SI D i .

[0059] Step 15) Calculate the temporal equilibrium degree of airspace complexity: According to the calculation method of the airspace complexity of a certain period described in Step 12), calculate the airspace complexities of each period within the time domain to be measured respectively, and calculate the variance of the airspace complexities of each period, which is the temporal equilibrium degree of airspace complexity within the time domain - airspace to be measured; the higher this value, the greater the difference in the airspace complexities of each period within the time domain - airspace to be measured, and the weaker the temporal equilibrium degree.

[0060] The calculation method of the time balance degree of the airspace complexity is as follows: Assume that in step 3), the time domain is divided into m time periods, the airspace is divided into n grids, and the airspace complexity of the i-th time period is C i ; the average complexity in this time domain-airspace is C; then the time balance degree value of the airspace complexity in the to-be-tested time domain-airspace is the variance of the airspace complexity of each time period, that is

[0061] Example:

[0062] The grid-based evaluation method for airspace complexity based on aircraft interaction relationships provided in this example includes the following steps carried out in sequence:

[0063] Step 1) Load aircraft operation trajectory data: The actual operation data of the aircraft loaded from the air traffic management data storage system is shown in Table 1. In this example, there are 18 aircraft in total, and the actual operation data of the aircraft includes the longitude, latitude, altitude, speed, heading, and climb rate of each aircraft at the current moment.

[0064] Step 2) Set the to-be-tested time domain-airspace parameters: The start and end times of the to-be-tested time domain are 00:00:00 - 00:06:00, and the to-be-tested airspace data is shown in Table 2. The to-be-tested airspace information includes the airspace longitude and latitude coordinates and the altitude range.

[0065] Step 3) Perform grid processing on the to-be-tested airspace: In this example, the length and width L of the grid S are both set to 20 nautical miles, and the height H S is set to 1000 meters; the to-be-tested airspace is divided into 4 grids, that is, n = 4, numbered I, II, III, and IV respectively, as Figure 2 shown.

[0066] Step 4) Perform fragmentation processing on the to-be-tested time domain: In this example, the time period T S is set to 3 minutes, and the to-be-tested time domain is divided into 2 time periods, that is, m = 2;

[0067] Step 5) Screen the set of aircraft passing through a certain grid in a certain time period: In this example, the buffer time Δt1 is set to 1 minute, and the buffer time Δt2 is set to 1 minute; after screening, there are 16 aircraft located in the to-be-tested time domain-airspace, numbered F01 - F16 respectively; the aircraft operation data is shown in Table 3, and the aircraft operation situation is as Figure 3 、 Figure 4 shown.

[0068] Step 6) Determine whether there is time overlap between two aircraft in the aircraft set: After judgment, aircraft F01 - F04 are in the same grid and there is time overlap; aircraft F05 - F08 are in the same grid and there is time overlap; aircraft F09 - F12 are in the same grid and there is time overlap; aircraft F13 - F16 are in the same grid and there is time overlap. The aircraft time overlap relationships for each time and each grid are shown in Tables 4 - 1 to 4 - 6.

[0069] Step 7) Determine whether interaction occurs between aircraft with time overlap: The aircraft interaction relationship types for each time and each grid are shown in Tables 5 - 1 to 5 - 6. Among them, horizontal interaction is represented by H, vertical interaction is represented by V, and speed interaction is represented by S; the speed difference threshold S0 is set to 35 km / h, the horizontal course angle threshold H0 is set to 20 degrees, and the positive climb rate threshold V0 is set to 20 m / s.

[0070] Step 8) Calculate the aircraft interaction duration within this time period and this grid: The number of pairwise interaction relationships between aircraft within each time and each grid is shown in Tables 6 - 1 to 6 - 6; after statistically analyzing the data of each aircraft for each time, the aircraft interaction durations for each time period and each grid shown in this embodiment are as shown in Table 7.

[0071] Step 9) Calculate the aircraft operation time within this time period and this grid: The aircraft operation durations for each time period and each grid are shown in Table 8.

[0072] Step 10) Calculate the grid interaction index for this time period and this grid; The grid interaction index statistical tables for each time period and each grid are shown in Table 9.

[0073] Step 11) Calculate the airspace interaction index for this time period: The airspace interaction indices for each time period are shown in Table 10.

[0074] Step 12) Calculate the airspace complexity of the airspace to be measured during this time period:

[0075] The airspace complexity of the I - th time period

[0076] The airspace complexity of the II - th time period

[0077] Step 13) Calculate the average complexity of the time - airspace to be measured:

[0078] Step 14) Calculate the spatial balance degree of the airspace complexity: C A_S = max 1≤i≤2 SI D i = 0.248.

[0079] Step 15) Calculate the time balance degree of the airspace complexity:

[0080] Table 1 Aircraft operation data table

[0081] Aircraft number longitude latitude Height(m) Speed ​​(km / h) Heading (degrees) Climb rate (m / s) 01 120°02′00″E 40°18′00″N 4800 800 090 0 02 120°08′00″E 40°13′00″N 4800 750 090 0 03 120°08′00″E 40°11′00″N 4500 725 270 0 04 120°05′00″E 40°15′00″N 4100 740 045 20 05 120°15′00″E 40°16′00″N 4500 780 270 0 06 120°17′00″E 40°08′00″N 4800 820 090 0 07 120°19′00″E 40°11′00″N 4600 725 225 -20 08 120°15′00″E 40°12′00″N 4100 740 045 20 09 120°02′00″E 40°07′00″N 3600 800 090 0 10 120°09′00″E 40°09′00″N 3900 775 270 0 11 120°05′00″E 40°02′00″N 3200 750 045 20 12 120°09′00″E 40°04′00″N 3200 800 135 -10 13 120°00′00″E 40°06′00″N 3800 700 135 -10 14 120°17′00″E 40°09′00″N 3900 750 270 0 15 120°13′00″E 40°02′00″N 3400 725 045 20 16 120°16′00″E 40°03′00″N 3600 800 090 0 17 120°03′00″E 40°22′00″N 3300 750 135 -10 18 120°23′00″E 40°04′00″N 3800 700 90 0

[0082] Table 2 Information of airspace to be tested

[0083] Longitude range 120°00′00″E-120°20′00″E Latitude range 40°00′00″N-40°20′00″N Height range 3000m-5000m

[0084] Table 3 Aircraft operation data in the airspace to be tested

[0085]

[0086] Table 4-1 Aircraft potential interaction statistics - Minutes 0-1 of Period I

[0087]

[0088] Table 4-2 Aircraft potential interaction statistics - 1st to 2nd minute of period I

[0089]

[0090] Table 4-3 Aircraft potential interaction statistics - 2nd to 3rd minute of period I

[0091]

[0092] Table 4-4 Aircraft potential interaction statistics - 3rd to 4th minutes of period II

[0093]

[0094] Table 4-5 Aircraft potential interaction statistics - 4th to 5th minutes of period II

[0095]

[0096] Table 4-6 Aircraft potential interaction statistics - Minutes 5-6 of Period II

[0097]

[0098] Table 5-1 Aircraft interaction type statistics table - Time period I, minutes 0-1

[0099]

[0100] Table 5-2 Aircraft interaction type statistics - 1st to 2nd minute of period I

[0101]

[0102] Table 5-3 Aircraft Interaction Type Statistics Table - Minutes 2-3 of Period I

[0103]

[0104] Table 5-4 Aircraft Interaction Type Statistics Table - Minutes 3-4 of Period II

[0105]

[0106] Table 5-5 Aircraft Interaction Type Statistics Table - Minutes 4-5 of Period II

[0107]

[0108] Table 5-6 Aircraft Interaction Type Statistics Table - Minutes 5-6 of Period II

[0109]

[0110] Table 6-1 Aircraft Interaction Quantity Statistics Table - Minutes 0-1 of Period I

[0111]

[0112] Table 6-2 Aircraft Interaction Quantity Statistics Table - Minutes 1-2 of Period I

[0113]

[0114] Table 6-3 Aircraft Interaction Quantity Statistics Table - Minutes 2-3 of Period I

[0115]

[0116] Table 6-4 Aircraft Interaction Quantity Statistics Table - Minutes 3-4 of Period II

[0117]

[0118] Table 6-5 Aircraft Interaction Quantity Statistics Table - Minutes 4-5 of Period II

[0119]

[0120] Table 6-6 Aircraft Interaction Quantity Statistics Table - Minutes 5-6 of Period II

[0121]

[0122] Table 7 Aircraft Interaction Duration Statistics Table within Each Grid

[0123] Grid No. Ⅰ Grid No. II Grid No. III Grid No. IV Minutes 0-1 2 0 0 0 Minutes 1-2 2 2 0 2 Minutes 2-3 11 16 11 13 Total for Period I 15 18 11 15 Grid No. Ⅰ Grid No. II Grid No. III Grid No. IV Minutes 3-4 7 16 11 13 Minutes 4-5 2 0 6 2 Minutes 5-6 0 0 0 0 Total for period II 9 16 19 15 Grid No. Ⅰ Grid No. II Grid No. III Grid No. IV Total time domain to be tested 24 34 28 30

[0124] Statistical Table of Aircraft Operation Duration in Each Grid

[0125] Grid No. Ⅰ Grid No. II Grid No. III Grid No. IV Total for Period I 8 7 6 6 Total for period II 5 5 8 6 Total time domain to be tested 13 12 14 12

[0126] Statistical Table of Interaction Index in Each Grid

[0127]

[0128] Calculation of Airspace Interaction Index

[0129] Aircraft interaction time Aircraft operating time Airspace Interaction Index Period I 15+18+11+15＝57 8+7+6+6＝27 57 / 27＝2.111 Period II 9+16+19+15＝59 5+5+8+6＝24 59 / 24＝2.458 Total time domain to be tested 24+34+28+30＝116 13+12+14+12＝51 116 / 51＝2.275

Claims

1. An airspace complexity grid evaluation method based on the interaction relationship of aircraft, characterized in that: The grid evaluation method for airspace complexity based on aircraft interaction relationships includes the following steps carried out in sequence: Step 1) Load aircraft operation trajectory data: Load the actual operation data of aircraft from the air traffic management data storage system, extract the data including the departure airport, arrival airport, aircraft type, actual departure time, actual arrival time, and the time stamps, longitudes, latitudes, altitudes, speeds, headings, and climb rates of the actual flight paths of the aircraft, and then store them in the database; Step 2) Set the time-domain and airspace parameters to be measured: Set the start and end times of the time domain to be measured; Set the longitude and latitude coordinates of each boundary point of the airspace to be measured and the altitude range allowed for aircraft operation within the airspace; Step 3) Perform rasterization processing on the airspace to be measured: According to the longitude and latitude coordinates of each boundary point of the airspace to be measured set in Step 2) and the height range within which aircraft are allowed to operate in the airspace, use multiple densely paved cuboid grids with a length and width of L s and a height of H S to divide the above-mentioned airspace to be measured to obtain multiple grids, and determine the boundary coordinate data of each grid; Step 4) Fragment the time domain to be measured: Divide the above-mentioned time domain to be measured into multiple time periods with a time period T S as the unit; Step 5) Screen the set of aircraft passing through a certain grid in a certain period: Select a certain grid divided in Steps 3) and 4), and according to the time stamps, longitudes, latitudes, and altitude data of the actual flight paths of the aircraft loaded in Step 1), screen out the aircraft passing through this grid during this period as the set of aircraft; The time for the aircraft to enter and leave the grid is in minutes. Subtract the buffer time Δt1 from the moment when the aircraft enters the grid, and add the buffer time Δt2 to the moment when the aircraft leaves the grid; Step 6) Judge whether there is time overlap among the aircraft in the set of aircraft: Traverse the set of aircraft obtained in Step 5), select any two aircraft as an aircraft group one by one, and judge whether there is cross-overlap in the passing times of each aircraft group. If so, set the potential interaction relationship value of this aircraft group for this grid to 1, otherwise set it to 0; Step 7) Judge whether spatial interaction occurs among the aircraft: Traverse the aircraft groups with a potential interaction relationship value of 1 obtained in Step 6), and according to the time stamps, longitudes, latitudes, and altitude data of the actual flight paths of the aircraft loaded in Step 1) and the boundary coordinate data of the grid determined in Step 3), judge minute by minute whether there are horizontal interaction, vertical interaction, and speed interaction situations among the aircraft within each aircraft group; If there is a horizontal interaction situation, set the horizontal interaction value of this aircraft group at this moment to 1, otherwise set it to 0; If there is a vertical interaction situation, set the vertical interaction value of this aircraft group at this moment to 1, otherwise set it to 0; If there is a speed interaction situation, set the speed interaction value of this aircraft group at this moment to 1, otherwise set it to 0; Step 8) Calculate the total interaction duration of the aircraft within this grid during this period: Traverse the horizontal interaction values, vertical interaction values, and speed interaction values of each aircraft group at each moment obtained in Step 7), and after summing them respectively, obtain the horizontal interaction duration, vertical interaction duration, and speed interaction duration of this grid during this period; Then add the horizontal interaction duration, vertical interaction duration, and speed interaction duration to obtain the total interaction duration of the aircraft within this grid during this period; Step 9) Calculate the aircraft operation time within the grid during this period: According to the aircraft set passing through this grid during this period obtained in Step 5), the timestamp, longitude, latitude, and altitude data of the actual flight path of the aircraft loaded in Step 1), and the grid boundary coordinate data determined in Step 3), retrieve the moments when each aircraft in the aircraft set enters and leaves this grid, and calculate the duration of each aircraft operating within this grid; sum up the durations of each aircraft operating within the aircraft set to obtain the aircraft operation time within this grid during this period; Step 10) Calculate the grid interaction index of this grid during this period: Divide the total interaction duration of aircraft in this grid during this period obtained in Step 8) by the aircraft operation time within this grid during this period obtained in Step 9), and the grid interaction index of this grid during this period is obtained; Step 11) Calculate the airspace interaction index of this period: According to the calculation method of the total interaction duration of aircraft in a certain grid during a certain period obtained in Step 8) and the aircraft operation time obtained in Step 9), calculate the total interaction duration and operation time of aircraft in each grid during this period, and sum up the total interaction duration and operation time of aircraft in each grid to obtain the airspace interaction duration and airspace operation time of this period; Then divide the above-mentioned airspace interaction duration of this period by the airspace operation time of this period, and the airspace interaction index of this period is obtained; Step 12) Calculate the airspace complexity of the airspace to be measured during this period: According to the calculation method of the grid interaction index of a certain grid during a certain period obtained in Step 10), calculate and sum up the grid interaction indexes of each grid during this period; then multiply the summation result by the airspace interaction index of this period obtained in Step 11), and the airspace complexity of this period is obtained; Step 13) Calculate the average complexity of the time-domain - airspace to be measured: According to the period obtained in Step 4) and the calculation method of the airspace complexity described in Step 12), calculate the airspace complexity of each period respectively, and then take the average value to obtain the average complexity of the airspace to be measured; Step 14) Calculate the spatial balance degree of airspace complexity: According to the calculation method of the grid interaction index of a certain grid during a certain period described in Step 10), and the start and end times of the time-domain to be measured set in Step 2), calculate the grid interaction indexes of each grid in each period within the time-domain to be measured, and calculate the variance of the grid interaction indexes of each grid within each period. Subsequently, take the maximum value of the variances of each period as the spatial balance degree of airspace complexity within the time-domain - airspace to be measured; Step 15) Calculate the temporal balance degree of airspace complexity: According to the calculation method of the airspace complexity of a certain period described in Step 12), calculate the airspace complexity of each period within this time-domain to be measured respectively, and calculate the variance of the airspace complexity of each period, which is the temporal balance degree of airspace complexity within the time-domain - airspace to be measured.

2. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, wherein: In step 7), the method for determining whether there is horizontal interaction between aircraft is as follows: traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time periods of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight paths of the aircraft described in step 1), and retrieve the horizontal headings of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their headings are represented by H t (a,k) and H t (b,k) respectively; let the heading angle threshold be H0. If the heading angle is greater than or equal to the heading angle threshold, that is, |H t (a,k) - H t (b,k)| ≥ H0, it is considered that there is horizontal interaction between the two aircraft at time t, that is, the horizontal interaction value corresponding to the aircraft group at time t is 1.

3. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, characterized in that: In step 7), the method for determining whether there is a vertical interaction between aircraft is as follows: traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time periods of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight paths of the aircraft described in step 1), and retrieve the climb rates of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their climb rates are represented by V t (a, k) and V t (b, k) respectively; the positive threshold of the climb rate of the aircraft is represented by V0, and the negative threshold is represented by -V0. If the climb rate of the aircraft is greater than or equal to the positive climb rate threshold V0, it is considered that the aircraft is in a climbing state; if the climb rate is less than or equal to the negative climb rate threshold -V0, it is considered that the aircraft is in a descending state; otherwise, it is considered that the aircraft is in a level flight state; detect the vertical flight states of the two aircraft. If the vertical flight states are different, it is considered that there is a vertical interaction between the two aircraft, that is, the vertical interaction value corresponding to this aircraft group at time t is 1.

4. The method for grid evaluation of airspace complexity based on aircraft interaction relationships according to claim 1, wherein: In step 7), the method for determining whether there is speed interaction between aircraft is as follows: traverse the aircraft groups with overlapping existence times obtained in step 6). For the overlapping time periods of two aircraft, query the timestamp, longitude, latitude, and altitude data of the actual flight paths of the aircraft described in step 1), and retrieve the speeds of each aircraft minute by minute. At time t, both aircraft a and b are in grid k, and their speeds are represented by S t (a, k) and S t (b, k); the speed difference threshold between the two aircraft is represented by S0. If the speed difference between the two aircraft is greater than or equal to the speed difference threshold S0, that is, |S t (a, k) - S t (b, k)| ≥ S0, it is considered that there is speed interaction between the two aircraft at time t, that is, the speed interaction value corresponding to the aircraft group at time t is 1.

5. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, wherein: In step 10), the method for calculating the grid interaction index of a certain grid in a certain period is as follows: Assume that in step 3), the time period is divided into m sub-periods, the airspace is divided into n grids, and the horizontal, vertical, and speed interaction durations of each aircraft group with respect to the j-th grid at each moment within the i-th period obtained in step 8) are summed respectively, which are the horizontal, vertical, and speed interaction times of the grid within this period, and are represented by respectively; the total interaction duration of aircraft within the grid is represented by which is the sum of the horizontal, vertical, and speed interaction times of the grid, that is The operation time of aircraft within the grid in this period is represented by respectively, and the grid interaction index is represented by It is calculated by dividing the interaction duration of aircraft within the grid by the operation time of aircraft within the grid, that is 6. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, wherein: In step 11), the calculation method of the airspace interaction index for a certain period is as follows: Assume that in step 3), the time domain is divided into m periods and the airspace is divided into n grids. Then the aircraft interaction duration of the j-th grid in the i-th period is The aircraft operation time of the j-th grid in the i-th period is The airspace interaction index AD for this period i Is the sum of the aircraft interaction durations of each grid in this period divided by the sum of the aircraft operation times in each grid, that is 7. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, wherein: In step 12), the method for calculating the airspace complexity during a certain period is as follows: Assume that in step 3), the time domain is divided into m periods and the airspace is divided into n grids. Then the grid interaction index of the j-th grid in the i-th period is The airspace interaction index of this period is AD i ; The airspace complexity C of this period i is the sum of the grid interaction indices of each grid in this period multiplied by the airspace interaction index of this period, that is 8. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, characterized in that: In step 13), the method for calculating the average complexity of the time domain - space domain to be measured is as follows: Assume that in step 3), the time domain is divided into m time periods, the space domain is divided into n grids, and the space complexity of the i-th time period is C i ; then the average complexity of this time domain - space domain is the average value of the space complexities of each time period, that is 9. The method for grid evaluation of airspace complexity based on aircraft interaction relationship according to claim 1, wherein: In step 14), the calculation method of the spatial balance degree of the airspace complexity is as follows: Assume that in step 3), the time domain is divided into m time periods, and the airspace is divided into n grids. The grid interaction index of the j-th grid in the i-th time period is Then the average value of the grid interaction indices of each grid in this time period The variance of the grid interaction indices of each grid Can be calculated separately. The spatial balance degree of the airspace complexity in the time domain-airspace to be measured is the maximum value of the variances of each time period, that is, C A_S = max 1≤i≤m SI D i .

10. The grid evaluation method for airspace complexity based on aircraft interaction relationships according to claim 1, wherein: In step 15), the time balance degree calculation method of the airspace complexity is as follows: Assume that in step 3), the time domain is divided into m time periods, the airspace is divided into n grids, and the airspace complexity of the i-th time period is C i ; The average complexity within this time domain - space domain is C; then the time balance value of the space complexity within the to - be - measured time domain - space domain is the variance of the space complexities of each time period, that is

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