A method and device for identifying clear-aircraft wake based on wind laser radar

Abstract

The present invention discloses a clear-aircraft wake identification method and device based on a wind-measuring laser radar, the method comprising: obtaining radial velocity data of a target area from a radar echo signal of the target area; obtaining a plurality of maximum value regions and minimum value regions of the radial velocity of the target area from the radial velocity data of the target area; combining a plurality of maximum value regions and minimum value regions in sequence, respectively calculating the straight-line distance from the center of the maximum value region and the center of the minimum value region in each combination to the radar, and comparing them with a set aircraft wake criterion, determining that a combination that meets the aircraft wake criterion forms an aircraft wake vortex. The present invention can accurately identify aircraft wakes in various background wind field environments, and precisely locate the center of the wake vortex and its influence range, thereby improving the accuracy and stability of aircraft wake identification, and greatly reducing the consumption of computing resources.

Description

Technical Field

[0001] The invention belongs to the technical field of radar detection, and in particular relates to a method and a device for recognizing a clear-air aircraft wake based on a wind-measuring laser radar. Background Art

[0002] The air pressure on the lower surface of the wing is higher than that on the upper surface, causing the air to flow from bottom to top and form a strong vortex, namely the aircraft wake. At present, under clear weather conditions, aircraft wake is mainly detected by lidar technology. Aircraft wake will bring a rolling moment to the aircraft flying behind, which may exceed the aircraft's control ability and cause the aircraft to lose control or be damaged, especially during takeoff and landing. Therefore, in order to ensure flight safety, it is necessary to maintain a certain wake separation distance between different types of aircraft. In view of this, the detection and parameter inversion of aircraft wake has become a key research topic in the field of aviation safety. The accuracy and reliability of existing wake identification algorithms in identifying key characteristic parameters of aircraft wake still need to be improved. Solving this problem is crucial to studying the impact of wake on aviation safety. Summary of the invention

[0003] In order to address the deficiencies in the prior art, the present invention provides a method and device for identifying clear-sky aircraft wake based on wind measuring laser radar, which can accurately identify aircraft wakes in various background wind environments and precisely locate the center of the wake vortex and its influence range, thereby improving the accuracy and stability of aircraft wake identification and significantly reducing the consumption of computing resources.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, a clear sky aircraft wake identification method based on wind measuring laser radar is provided, comprising: obtaining radial velocity data of a target area from a radar echo signal of the target area; obtaining a plurality of maximum value areas of the radial velocity of the target area from the radial velocity data of the target area; obtaining a plurality of minimum value areas of the radial velocity of the target area from the radial velocity data of the target area; combining the plurality of maximum value areas and minimum value areas in sequence, respectively calculating the straight-line distances from the center of the maximum value area and the center of the minimum value area in each combination to the radar, and comparing them with the set aircraft wake criterion, to determine that the combination that meets the aircraft wake criterion forms an aircraft wake vortex.

[0006] Furthermore, the radar echo signal of the target area is a radar echo signal obtained by performing RHI scanning on the target area by using a wind Doppler laser radar.

[0007] Furthermore, the method also includes preprocessing the radial velocity data of the target area, that is, interpolating the radial velocity data in polar coordinate form to grid points in a Cartesian coordinate system to obtain radial velocity data in a Cartesian coordinate system.

[0008] Further, obtaining a plurality of maximum value regions of the radial velocity of the target region includes: searching for the first maximum value point of the radial velocity in the radial velocity data of the target region. , the first maximum point of radial velocity is the center of the circle, The circular area with a radius of , is defined as the first maximum area of ​​radial velocity in the searched target area ;in, In order to make the average radial velocity of the positive radial velocity area in the circular region greater than The maximum radius of The first maximum point radial velocity; repeatedly searching several times in the radial velocity data of the target area to obtain several maximum value areas of the radial velocity of the target area, and the center of each maximum value area of ​​the radial velocity is not within the range of the maximum value area of ​​the radial velocity that has been searched.

[0009] Further, obtaining a plurality of minimum value regions of the radial velocity of the target region includes: searching for the first minimum value point of the radial velocity in the radial velocity data of the target region; , the first minimum point of radial velocity is the center of the circle, The circular area with a radius of is defined as the first minimum area of ​​radial velocity in the searched target area. ;in, In order to make the average radial velocity of the negative radial velocity area in the circular region less than The maximum radius of The first minimum point radial velocity; repeatedly searching several times in the radial velocity data of the target area to obtain several minimum value areas of the radial velocity of the target area, and the center of each minimum value area of ​​the radial velocity is not within the range of the minimum value area of ​​the radial velocity that has been searched.

[0010] Furthermore, the aircraft wake criterion is:

[0011] ;

[0012] and ;

[0013] in, represents the straight-line distance from the center of the i-th maximum area to the radar, represents the straight-line distance from the center of the jth minimum area to the radar, represents the radial velocity of the center of the ith maximum region, represents the radial velocity at the center of the jth minimum region.

[0014] Furthermore, the vortex center position of the aircraft wake vortex is: ,in, and are the center coordinates of the corresponding maximum regions, and are the center coordinates of the corresponding minimum regions respectively; the vortex core radius is: ,in, The corresponding maximum area The radius of The corresponding minimum area The radius of .

[0015] In a second aspect, a clear sky aircraft wake identification device based on a wind measuring laser radar is provided, comprising: a radial velocity acquisition module, used to obtain radial velocity data of a target area from a radar echo signal of the target area; a maximum area search module, used to obtain a plurality of maximum areas of the radial velocity of the target area from the radial velocity data of the target area; a minimum area search module, used to obtain a plurality of minimum areas of the radial velocity of the target area from the radial velocity data of the target area; a wake identification module, used to sequentially combine a plurality of maximum areas with minimum areas, respectively calculate the straight-line distances from the center of the maximum area and the center of the minimum area in each combination to the radar, and compare them with the set aircraft wake criterion to determine that the combination that meets the aircraft wake criterion forms an aircraft wake vortex.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention obtains radial velocity data of the target area from the radar echo signal of the target area; obtains a plurality of maximum value areas and minimum value areas of the radial velocity of the target area from the radial velocity data of the target area; combines the plurality of maximum value areas and minimum value areas in sequence, respectively calculates the straight-line distance from the center of the maximum value area and the center of the minimum value area in each combination to the radar, and compares them with the set aircraft wake criterion, determines that the combination that meets the aircraft wake criterion forms an aircraft wake vortex, can accurately identify the aircraft wake in various background wind field environments, and accurately locates the center of the wake vortex and its influence range, thereby improving the accuracy and stability of aircraft wake identification and greatly reducing the consumption of computing resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the radial velocity distribution diagram and identification result of the typical wake;

[0018] Figure 21 is a diagram showing the effect of wake vortex identification using a clear-aircraft wake vortex identification method based on a wind-measuring laser radar provided in an embodiment of the present invention, wherein (a) to (e) are the development process of an aircraft wake vortex from appearance to dissipation, the black circle and the center of the circle in the figure are the aircraft wake vortex and vortex center positions identified by using a clear-aircraft wake vortex identification method based on a wind-measuring laser radar provided in an embodiment of the present invention, and (f) is the background wind field after the aircraft wake vortex dissipates;

[0019] Figure 3 The main process of wake vortex identification using a clear sky aircraft wake vortex identification method based on wind laser radar provided by an embodiment of the present invention is schematically shown. Figure 1 ;

[0020] Figure 4 The main process of wake vortex identification using a clear sky aircraft wake vortex identification method based on wind laser radar provided by an embodiment of the present invention is schematically shown. Figure 2 ;

[0021] Figure 5 The main process of wake vortex identification using a clear sky aircraft wake vortex identification method based on wind laser radar provided by an embodiment of the present invention is schematically shown. Figure 3 ;

[0022] Figure 6 It is a schematic diagram of the main process of a clear-aircraft wake vortex identification method based on a wind-measuring laser radar provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0024] Embodiment 1

[0025] like Figure 3~Figure 6 As shown, a clear sky aircraft wake recognition method based on wind laser radar includes:

[0026] The radial velocity data of the target area is obtained from the radar echo signal of the target area; a plurality of maximum value areas of the radial velocity of the target area are obtained from the radial velocity data of the target area; a plurality of minimum value areas of the radial velocity of the target area are obtained from the radial velocity data of the target area; a plurality of maximum value areas and minimum value areas are sequentially combined, and the straight-line distances from the center of the maximum value area and the center of the minimum value area in each combination to the radar are calculated respectively, and compared with the set aircraft wake criterion, and it is determined that the combination that meets the aircraft wake criterion forms an aircraft wake vortex.

[0027] (a) Obtain radial velocity data of the target area from the radar echo signal of the target area.

[0028] Step 1: According to the range, height, distance and azimuth of the detected target, determine the scanning elevation angle, range and scanning frequency of the lidar (wind Doppler lidar), perform multiple continuous RHI scans (i.e. range height scans) on the target area, and obtain the radar echo signal of the target area.

[0029] Step 2: Each scan will obtain a radial distribution velocity corresponding to a time, that is, the radial velocity data of the target area. In order to facilitate data processing, the radial velocity data of the target area is preprocessed, that is, the radial velocity data in polar coordinate form is converted into Interpolate to the grid points in the Cartesian coordinate system to obtain the radial velocity distribution in the Cartesian coordinate system .like Figure 1 Shown are the radial velocity distribution diagram and identification results of a typical wake.

[0030] (ii) Obtaining several maximum value regions of radial velocity of the target area from the radial velocity data of the target area.

[0031] Step 3: Search for the first maximum point of radial velocity within the radar detection area , the first maximum point of radial velocity is the center of the circle, The circular area with a radius of , is defined as the first maximum area of ​​radial velocity in the searched target area ,in, In order to make the average radial velocity of the positive radial velocity area in the circular region greater than The maximum radius of The first maximum point The radial velocity.

[0032] Step 4: Repeat step 3 four times to search for the second to fifth maximum value areas of radial velocity , , , , ensuring that the center of each maximum area is not within the range of the maximum area of ​​the radial velocity that has been found.

[0033] (iii) Obtaining several minimum value regions of radial velocity of the target area from the radial velocity data of the target area.

[0034] Step 5: Search for the first minimum point of radial velocity in the radar detection area , the first minimum point of radial velocity is the center of the circle, The circular area with a radius of is defined as the first minimum area of ​​radial velocity in the searched target area. ;in, In order to make the average radial velocity of the negative radial velocity area in the circular area less than The maximum radius of The first minimum point The radial velocity.

[0035] Step 6: Repeat step 5 four times to search for the second to fifth minimum areas of radial velocity. , , , , ensuring that the center of each minimum region is not within the range of the minimum region of radial velocity that has been found.

[0036] (iv) Combine several maximum value areas and minimum value areas in sequence, calculate the straight-line distance from the center of the maximum value area and the center of the minimum value area in each combination to the radar, and compare them with the set aircraft wake turbulence criterion to determine whether the combination that meets the aircraft wake turbulence criterion forms an aircraft wake vortex.

[0037] Step 7: Search for the maximum radial velocity area and the minimum region Combine them in sequence, calculate the straight-line distance from the center of the two extreme value areas to the radar, and compare them with the set aircraft wake criterion to determine that the combination that meets the aircraft wake criterion forms an aircraft wake vortex; among which, the aircraft wake criterion is:

[0038] ;

[0039] and ;

[0040] in, represents the straight-line distance from the center of the i-th maximum area to the radar, represents the straight-line distance from the center of the jth minimum area to the radar, represents the radial velocity of the center of the i-th maximum region, represents the radial velocity at the center of the jth minimum region.

[0041] That is, the straight-line distance from the center of the two extreme regions to the radar, if the condition is met ,and and If the difference is greater than 3m / s, it is considered that this combination forms an aircraft wake vortex. The vortex center position is and Midpoint of the line connecting the centers of the circles ,in, and are the center coordinates of the corresponding maximum regions, and are the center coordinates of the corresponding minimum regions; the vortex core radius is and One third of the radius and ,in, The corresponding maximum area The radius of The corresponding minimum area The radius of Figure 2 The figure shows the effect diagram obtained by using a clear-aircraft wake identification method based on a wind-measuring laser radar provided by the present invention to identify wake vortices, wherein (a) to (e) are the development process of an aircraft wake from appearance to dissipation, the black circle and the center of the circle in the figure are the aircraft wake vortex and vortex center positions identified by using a clear-aircraft wake identification method based on a wind-measuring laser radar provided by an embodiment of the present invention, and (f) is the background wind field after the aircraft wake dissipates.

[0042] The present invention can be used to process the echo radial velocity data of the wind Doppler laser radar, and can accurately identify the aircraft wake in various background wind field environments, and precisely locate the center of the wake vortex and its influence range. It not only shows a high degree of accuracy and stability in wake identification, but also has significant advantages in computing resource consumption. Its time complexity is O(a×n), where n represents the total amount of radial velocity data in the radar detection area after interpolation conversion to the Cartesian coordinate system, and a is the number of iterations for searching the extreme value area. In addition, the present invention has extremely low requirements for computing memory. When running in a 64-bit CPP compiler, the memory occupancy is only about 1MB, which is a huge advantage for systems with limited memory resources.

[0043] Embodiment 2

[0044] Based on the clear-aircraft wake vortex identification method based on wind laser radar described in Embodiment 1, this embodiment provides a clear-aircraft wake vortex identification device based on wind laser radar, including:

[0045] A radial velocity acquisition module is used to acquire radial velocity data of a target area from a radar echo signal of the target area;

[0046] A maximum value region search module is used to obtain a number of maximum value regions of the radial velocity of the target area from the radial velocity data of the target area;

[0047] A minimum value region search module is used to obtain a number of minimum value regions of the radial velocity of the target region from the radial velocity data of the target region;

[0048] The wake identification module is used to combine several maximum value areas and minimum value areas in sequence, calculate the straight-line distance from the center of the maximum value area and the center of the minimum value area in each combination to the radar, and compare them with the set aircraft wake turbulence criterion to determine whether the combination that meets the aircraft wake turbulence criterion forms an aircraft wake vortex.

[0049] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0050] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0051] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0052] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

Claims

1. A clear-air aircraft wake identification method based on wind laser radar, characterized in that: include: Acquire radial velocity data of the target area from the radar echo signal of the target area; Acquire several maximum value regions of radial velocity of the target area from radial velocity data of the target area; Acquire several minimum value regions of radial velocity of the target area from radial velocity data of the target area; Combine several maximum value areas and minimum value areas in sequence, calculate the straight-line distances from the center of the maximum value area and the center of the minimum value area in each combination to the radar, and compare them with the set aircraft wake criterion to determine that the combination that meets the aircraft wake criterion forms an aircraft wake vortex; Wherein, the aircraft wake criterion is: ； and ; in, represents the straight-line distance from the center of the i-th maximum area to the radar, represents the straight-line distance from the center of the jth minimum area to the radar, represents the radial velocity of the center of the i-th maximum region, represents the radial velocity at the center of the jth minimum region.

2. The clear sky aircraft wake identification method based on wind laser radar according to claim 1 is characterized in that: The radar echo signal of the target area is a radar echo signal obtained by performing RHI scanning on the target area by using a wind Doppler laser radar.

3. The clear sky aircraft wake identification method based on wind laser radar according to claim 1 is characterized in that: The method also includes preprocessing the radial velocity data of the target area, that is, interpolating the radial velocity data in polar coordinate form to grid points in a Cartesian coordinate system to obtain radial velocity data in a Cartesian coordinate system.

4. The clear sky aircraft wake identification method based on wind laser radar according to claim 1 is characterized in that: Get several maximum value areas of radial velocity in the target area, including: Search for the first maximum point of radial velocity in the radial velocity data of the target area , the first maximum point of radial velocity is the center of the circle, The circular area with a radius of , is defined as the first maximum area of ​​radial velocity in the searched target area ;in, In order to make the average radial velocity of the positive radial velocity area in the circular region greater than The maximum radius of The first maximum point The radial velocity of The radial velocity data of the target area is searched repeatedly for several times to obtain several maximum value areas of the radial velocity of the target area, and the center of each maximum value area of ​​the radial velocity is not within the range of the maximum value area of ​​the radial velocity that has been searched.

5. The clear sky aircraft wake identification method based on wind laser radar according to claim 1 is characterized in that: Get several minimum value areas of radial velocity in the target area, including: Search for the first minimum point of radial velocity in the radial velocity data of the target area , the first minimum point of radial velocity is the center of the circle, The circular area with a radius of is defined as the first minimum area of ​​radial velocity in the searched target area. ;in, In order to make the average radial velocity of the negative radial velocity area in the circular area less than The maximum radius of The first minimum point The radial velocity of The radial velocity data of the target area is searched repeatedly for several times to obtain several minimum value areas of the radial velocity of the target area, and the center of each minimum value area of ​​the radial velocity is not within the range of the minimum value area of ​​the radial velocity that has been searched.

6. The clear sky aircraft wake identification method based on wind laser radar according to claim 1 is characterized in that: The vortex center position of the aircraft wake vortex is: ,in, and are the center coordinates of the corresponding maximum regions, and are the center coordinates of the corresponding minimum regions respectively; the vortex core radius is: ,in, The corresponding maximum area The radius of The corresponding minimum area The radius of .

7. A clear-aircraft wake identification device based on wind laser radar, characterized in that: include: A radial velocity acquisition module is used to acquire radial velocity data of a target area from a radar echo signal of the target area; A maximum value region search module is used to obtain a number of maximum value regions of the radial velocity of the target area from the radial velocity data of the target area; A minimum value region search module is used to obtain a number of minimum value regions of the radial velocity of the target region from the radial velocity data of the target region; The wake identification module is used to sequentially combine a plurality of maximum value areas and minimum value areas, respectively calculate the straight-line distance from the center of the maximum value area and the center of the minimum value area in each combination to the radar, and compare them with the set aircraft wake criterion to determine that the combination that meets the aircraft wake criterion forms an aircraft wake vortex; Wherein, the aircraft wake criterion is: ； and ; in, represents the straight-line distance from the center of the i-th maximum area to the radar, represents the straight-line distance from the center of the jth minimum area to the radar, represents the radial velocity of the center of the i-th maximum region, represents the radial velocity at the center of the jth minimum region.

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