Radar speed measurement method, radar, radar speed measurement equipment, server and storage medium

Abstract

The embodiment of the invention discloses a radar speed measurement method, a radar, radar speed measurement equipment, a server and a storage medium. The method comprises the following steps: acquiring a measurement parameter set between a radar and a to-be-measured target; determining position information of the to-be-measured target relative to the radar according to the measurement parameter set; the relative movement speed of the to-be-measured target in the beam sight direction of the radar is obtained through radar measurement; and according to the relative movement speed and the position information, determining the absolute movement speed of the to-be-detected target in the movement direction of the to-be-detected target. By calculating the relative position information of the to-be-measured target, the speed conversion problem under the three-dimensional model is solved, the speed of the target in the actual driving direction can be accurately measured at any height and any pitch angle in the three-dimensional space, and therefore law enforcement departments can judge and track violations more conveniently.

Description

[0001] The application number of the parent case of this invention is "202111266065.7", and the application date is October 28, 2021, which is a divisional application. Technical Field

[0002] The embodiments of the present invention relate to the technical field of radar speed measurement, and in particular to a radar speed measurement method, a radar, a radar speed measurement device, a server and a storage medium. Background Art

[0003] With the rapid development of global cities, the number of vehicles in cities has increased, the transportation network has become increasingly complex, and intercity trains, high-speed railways and other transportation tools have also developed rapidly. While the urban transportation network brings convenience to people's lives, the situation of too many vehicles and roads has also buried hidden dangers to traffic safety and left more problems for traffic control and management.

[0004] In order to judge traffic violations, radar is usually used to measure speed in order to obtain the correct vehicle speed. However, the existing traffic speed radars only support working modes at fixed heights and fixed pitch angles. Accordingly, the existing radar data acquisition models are basically built on two-dimensional planes. When working in three-dimensional space, the three-dimensional pitch angle will cause the existing data acquisition model to fail. At the same time, the existence of the pitch angle in the three-dimensional data acquisition plane will cause the data acquisition plane to rotate, resulting in large errors in the existing speed identification results. Summary of the invention

[0005] The embodiment of the present invention provides a radar speed measurement method, a radar, a radar speed measurement device, a server and a storage medium, so as to accurately measure the moving speed of a target at any height and pitch angle in a three-dimensional space.

[0006] In a first aspect, an embodiment of the present invention provides a radar speed measurement method, the method comprising:

[0007] Obtaining a measurement parameter set between the radar and the target to be measured;

[0008] Determine the position information of the target to be measured relative to the radar according to the measurement parameter set;

[0009] The relative moving speed of the target to be measured along the line of sight of the radar beam is obtained by measuring the radar;

[0010] The absolute moving speed of the target to be measured along its moving direction is determined according to the relative moving speed and the position information.

[0011] Optionally, the obtaining of a set of measurement parameters between the radar and the target to be measured at least includes: obtaining a target distance, a target height difference and a target horizontal angle between the radar and the target to be measured;

[0012] The step of determining the absolute moving speed of the target to be measured along its moving direction according to the relative moving speed and the position information at least comprises:

[0013] The absolute moving speed is determined according to the relative moving speed, the instantaneous azimuth angle and the instantaneous elevation angle of the target to be detected relative to the radar.

[0014] Optionally, obtaining the target distance between the radar and the target to be measured includes:

[0015] Transmitting a frequency modulated continuous wave signal through the radar and receiving a reflected echo signal of the target to be measured;

[0016] Performing digital down-conversion on the reflected echo signal and sorting it into a two-dimensional matrix, and then obtaining a two-dimensional range Doppler matrix corresponding to the target to be measured by a two-dimensional fast Fourier transform;

[0017] The target distance is determined by a constant false alarm detection algorithm according to the two-dimensional range Doppler matrix.

[0018] Optionally, the acquiring a target horizontal angle between the radar and the target to be measured includes:

[0019] Determine a corresponding azimuth guidance vector and a signal vector for estimating a direction of arrival according to the target distance and the target height difference;

[0020] The direction of arrival is estimated according to the azimuth steering vector and the signal vector to obtain the target horizontal angle.

[0021] Optionally, the radar is carried on a drone, and obtaining the target height difference between the radar and the target to be measured includes:

[0022] The target height difference is measured by the flight control system of the UAV.

[0023] Optionally, the radar is carried on a drone, and before determining the absolute moving speed according to the relative moving speed, the instantaneous azimuth angle and the instantaneous pitch angle of the target to be measured relative to the radar, the method further includes:

[0024] Obtaining the actual flight speed of the drone and the pitch angle information of the gimbal;

[0025] Projecting the actual flight speed onto the beam line of sight direction according to the pitch angle information to obtain a projected flight speed;

[0026] Correspondingly, determining the absolute moving speed according to the relative moving speed, the instantaneous azimuth angle and the instantaneous pitch angle of the target to be measured relative to the radar includes:

[0027] Determine the target absolute speed of the target to be measured along the beam line of sight direction according to the relative moving speed and the projected flight speed;

[0028] The absolute moving speed is determined according to the target absolute speed, the instantaneous azimuth angle, and the instantaneous pitch angle.

[0029] Optionally, the target distance, the target height difference, the target horizontal angle, the instantaneous azimuth angle, and the instantaneous pitch angle satisfy the following relationship:

[0030]

[0031] Wherein, γ represents the instantaneous azimuth, ψ represents the instantaneous pitch angle, H represents the target height difference, R represents the target distance, θ radar represents the target horizontal angle, and asin() represents the inverse sine function.

[0032] Optionally, the relative moving speed, the absolute moving speed, the instantaneous azimuth angle, and the instantaneous pitch angle satisfy the following relationship:

[0033]

[0034] Among them, v c represents the absolute moving speed, v r represents the relative moving speed, γ represents the instantaneous azimuth angle, and ψ represents the instantaneous pitch angle.

[0035] In a second aspect, an embodiment of the present invention further provides a radar, the radar comprising:

[0036] one or more processors;

[0037] A memory for storing one or more programs;

[0038] When the one or more programs are executed by the one or more processors, the one or more processors implement the radar speed measurement method provided by any embodiment of the present invention.

[0039] In a third aspect, an embodiment of the present invention further provides a radar speed measuring device, which includes multiple radars provided by any embodiment of the present invention, and the multiple radars are used to measure the speed of the same target to be measured to obtain the absolute moving speed of the target to be measured along its own moving direction.

[0040] Optionally, measuring the speed of the same target to be measured to obtain the absolute moving speed of the target to be measured along its own moving direction includes:

[0041] The multiple radars measure the speed of the same target to be measured to obtain absolute moving speed samples measured by each radar;

[0042] Vector averaging is performed on each of the absolute moving speed samples to obtain the absolute moving speed.

[0043] Optionally, performing vector averaging on each of the absolute moving speed samples to obtain the absolute moving speed includes: performing vector averaging on each of the absolute moving speed samples to obtain a vector average speed;

[0044] determining an error of each of the absolute moving velocity samples relative to the vector average velocity;

[0045] If each of the errors does not exceed a preset error, the vector average speed is used as the absolute moving speed.

[0046] Optionally, performing vector averaging on each of the absolute moving speed samples to obtain the absolute moving speed includes:

[0047] Performing vector averaging on each of the absolute moving speed samples to obtain a first vector average speed;

[0048] determining an error of each of the absolute moving velocity samples relative to the first vector average velocity;

[0049] The absolute moving speed samples whose errors are greater than the preset errors are screened out, and then the remaining absolute moving speed samples are vector averaged to obtain a second vector average speed;

[0050] The second vector average speed is used as the absolute moving speed.

[0051] In a fourth aspect, an embodiment of the present invention further provides a radar speed measuring device, which includes multiple radars provided by any embodiment of the present invention, and the multiple radars are used to measure the speed of multiple targets to be measured to obtain the absolute moving speed of the multiple targets to be measured along their own moving direction.

[0052] Optionally, the moving directions of the multiple targets to be detected are different.

[0053] In a fifth aspect, an embodiment of the present invention further provides a server, which is used for:

[0054] Receiving the absolute moving speed of the target to be measured uploaded by the radar speed measuring device provided by any embodiment of the present invention;

[0055] Alternatively, receiving the absolute moving speeds of the multiple targets to be measured uploaded by the radar speed measuring device provided by any embodiment of the present invention;

[0056] The absolute moving speed of the target to be measured or the multiple targets to be measured is displayed on the display screen of the server, so that the user can determine whether the target to be measured or the multiple targets to be measured are speeding.

[0057] In a sixth aspect, an embodiment of the present invention further provides an unmanned aerial vehicle, comprising the radar speed measurement device provided by any embodiment of the present invention, wherein a plurality of the radars are installed on the nose of the unmanned aerial vehicle.

[0058] Optionally, the nose of the aircraft is provided with a gimbal, and the radar is installed on the gimbal.

[0059] In the seventh aspect, an embodiment of the present invention further provides an unmanned aerial vehicle, comprising the radar speed measurement device provided by any embodiment of the present invention, wherein a plurality of the radars are respectively installed on the nose, tail, left side and right side of the fuselage of the unmanned aerial vehicle.

[0060] In an eighth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the radar speed measurement method provided by any embodiment of the present invention.

[0061] The embodiment of the present invention provides a radar speed measurement method, which first obtains a measurement parameter set between the radar and the target to be measured, and then determines the position information of the target to be measured relative to the radar based on the measurement parameter set, and at the same time measures the relative moving speed of the target to be measured along the beam line of sight direction through the radar, so as to determine the absolute moving speed of the target to be measured along its own moving direction based on the relative moving speed and the position information. The radar speed measurement method provided by the embodiment of the present invention solves the speed conversion problem under the three-dimensional model by calculating the relative position information of the target to be measured, and realizes accurate measurement of the speed of the target in the actual driving direction at any height and any pitch angle in three-dimensional space, thereby making it easier for law enforcement departments to determine and track violations. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A flow chart of a radar speed measurement method provided in Embodiment 1 of the present invention;

[0063] Figure 2 A schematic diagram of the structure of a radar three-dimensional data acquisition model provided in the first embodiment of the present invention;

[0064] Figure 3 A schematic diagram of the structure of a radar speed measuring device provided in Embodiment 2 of the present invention;

[0065] Figure 4This is a schematic diagram of the structure of a radar provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0066] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0067] It should be mentioned before discussing the exemplary embodiments in more detail that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the steps as sequential processes, many of the steps therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of the steps can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0068] With the popularization and civilian use of drones, the cost of using drones is getting lower and lower. They have played an increasingly important role in the police, urban management, agriculture, geology, electricity, disaster relief, video shooting and other industries. Drones can also meet the needs of many application scenarios in the transportation industry. As the "third eye flying in the air", drones provide great convenience for safety supervision and emergency protection in the field of transportation. Due to the large traffic flow and severe congestion, drone law enforcement departments can ensure that when traffic police fail to arrive at the scene in time, drones can arrive at the scene as soon as possible, and conduct aerial photography, recording, evidence collection and traffic diversion to avoid more serious traffic congestion. At the same time, drones can also be used for intelligent tracking of illegal vehicles on highways or other relatively open scenes, and can also implement autonomous flight through the flight control system to achieve intelligent monitoring. The embodiment of the present invention takes the radar mounted on the drone as an example for explanation. Of course, the radar can also be mounted on other airborne equipment, and the embodiment of the present invention does not limit this.

[0069] Embodiment 1

[0070] Figure 1 This is a flow chart of the radar speed measurement method provided in the first embodiment of the present invention. This embodiment is applicable to the case of monitoring the speed of various vehicles. The method can be executed by the radar provided in the embodiment of the present invention. The radar can be implemented by hardware or hardware plus software, and multiple radars constitute the radar speed measurement device. Figure 1 As shown, the specific steps include:

[0071] S11. Obtain a set of measurement parameters between the radar and the target to be measured.

[0072] Among them, the target to be measured can be a vehicle, ship or other means of transportation, and the radar used can be a millimeter-wave radar. The millimeter-wave radar has the characteristics of small size, light weight and high spatial resolution, and has a strong ability to penetrate fog, smoke and dust. It can be used all day and all night, and its anti-interference and anti-stealth capabilities are also better than others. It can also distinguish and identify very small targets, and can identify multiple targets at the same time. By using millimeter-wave radar, the accuracy of the final speed measurement result can be improved. Optionally, the acquisition of the measurement parameter set between the radar and the target to be measured at least includes: acquiring the target distance, target height difference and target horizontal angle between the radar and the target to be measured, that is, the measurement parameter set can at least include the target distance, target height difference and target horizontal angle, and can further include parameters such as the attitude of the airborne device on which the radar is mounted. For example, if the mounted device is a drone, the measurement parameter set can be parameters such as the attitude of the drone. Specifically, if Figure 2 As shown, first, the radar coordinate system CXYZ can be established with the position C of the millimeter-wave radar as the origin, the vertical radar antenna plane as the X-axis, the radar center direction as the Z-axis, and the Y-axis determined according to the right-hand rule. Then, the projection O of the millimeter-wave radar position on the ground is taken as the origin, the same direction as the X-axis as the Y1-axis, the vertical ground upward as the Z1-axis, and the direction perpendicular to the Y1-axis on the ground as the X1-axis to establish the driving coordinate system OX1Y1Z1, where the X1-axis can be parallel to the moving direction of the target to be measured, that is, it can be the road direction, where the Z-axis intersects the X1-axis at point B. Assume that there is a target to be measured at any point D in the scene, and the straight-line distance from the radar to point D is R. A straight line DG perpendicular to OB is made through point D, and a straight line GE perpendicular to CB is made through point G. From the three perpendicular line theorem, DE⊥BC is obtained, DQ⊥plane XCZ is made in the XCZ plane, and a straight line QJ perpendicular to CX is made through point D, and OD, CD, CG, CQ and EQ are connected respectively. Among them, the target distance between the millimeter-wave radar and the target to be measured is R, the target height difference is H, the target horizontal angle is the angle between the line connecting the millimeter-wave radar and the target to be measured and the vertical plane of the ground where the radar normal is located, that is, ∠DCG. In addition, Rs is the radar center slant distance, that is, BC, ∠γ is the instantaneous azimuth of the target to be measured relative to the millimeter-wave radar, ∠ψ is the instantaneous pitch angle of the target to be measured relative to the millimeter-wave radar, and ∠α is the radar center pitch angle, that is, the angle between the radar normal direction and the horizontal direction when the millimeter-wave radar is working.

[0073] Optionally, the acquisition of the target distance between the radar and the target to be measured includes: transmitting a frequency modulated continuous wave signal through the radar, and receiving the reflected echo signal of the target to be measured; performing digital down-conversion on the reflected echo signal, and sorting it into a two-dimensional matrix, and then obtaining a two-dimensional distance Doppler matrix corresponding to the target to be measured through a two-dimensional fast Fourier transform; and determining the target distance through a constant false alarm detection algorithm according to the two-dimensional distance Doppler matrix. Specifically, a frequency modulated continuous wave (FMCW) radar can be used to transmit a frequency modulated continuous wave signal, and the frequency of the frequency modulated continuous wave signal can change linearly within each frequency modulation cycle. When the reflected echo signal is received, the reflected echo signal can be firstly digitally down-converted, and then the sample values ​​are sorted into a two-dimensional matrix, and then the time domain echo signal is transformed into a frequency domain dimension through a two-dimensional (2-D) fast Fourier transform (FFT), so as to obtain a two-dimensional Doppler matrix (RDM) corresponding to the target to be measured, and the target distance R of the target to be measured can be obtained by combining the constant false alarm detection (CFAR) algorithm.

[0074] Optionally, the acquisition of the target horizontal angle between the radar and the target to be measured includes: determining the corresponding azimuth steering vector and the signal vector for estimating the wave direction according to the target distance and the target height difference; estimating the wave direction according to the azimuth steering vector and the signal vector to obtain the target horizontal angle. Wherein, the steering vector is the response of all array elements of the array antenna to a narrowband signal source with unit energy. Since the array response is different in different directions, the steering vector and the direction of the signal source are interrelated. The uniqueness of this correlation depends on the geometric structure of the array. For the same array element array, each element of the steering vector has a unit amplitude. Specifically, for the target to be measured, in order to generate an N-dimensional vector, a radar array consisting of N antennas is required. It is assumed that the antenna element spacing is d=λ / 2, where λ is the wavelength. Assuming that the angular position of a point target in space relative to the radar is (γ, ψ), where γ∈(-π / 2, π / 2) and ψ∈(0, π / 2) represent the instantaneous azimuth and instantaneous elevation angles corresponding to the arbitrary point target, the signal vector s used to estimate the direction of arrival (DOA) can be expressed as

[0075] s=A·a(γ,ψ)

[0076] Where A represents the scattering coefficient of any point target, and a(γ,ψ) represents the signal steering vector, which can be expressed as

[0077] a(γ,ψ)=[1,e -j2πdsinγcosψ / λ , …e -j2π(N-1)dsinγcosψ / λ ] H

[0078] For the traditional one-dimensional DOA estimation, the steering vector considering only the azimuth angle can be expressed as

[0079] b=[1,e -j2πdsinγ / λ , …e -j2π(N-1)dsinγ / λ ] H

[0080] Therefore, the estimated azimuth angle can be obtained by the following method

[0081]

[0082] To solve the three-dimensional angle measurement problem, in this embodiment, taking into account the height difference H between any point target and the radar, optionally, the radar is carried on a drone, and obtaining the target height difference between the radar and the target to be measured includes: measuring the target height difference through the flight control system of the drone, that is, the height difference can be accurately measured by the flight control system of the drone, so as to use it for two-dimensional DOA estimation of other point targets.

[0083] After determining the target distance R and target height difference H, Figure 2 As shown, the instantaneous pitch angle between the radar and any point target can be expressed as

[0084]

[0085] Therefore, the azimuth steering vector corresponding to the pitch angle caused by the altitude can be expressed as

[0086]

[0087] Where d is the uniform array element spacing, N is the number of receiving antennas, [] H represents the transposed conjugate of the matrix. At this time, the target horizontal angle estimated by the direction of arrival is

[0088]

[0089] Combined with the above steering vector expression, when using a one-dimensional linear MIMO array for angle measurement, the angle between the radar and the target D to be measured is θ radar , combined with Figure 2 The geometric relationship in

[0090] sin∠θ radar =cos∠DCQ*sin∠QCE

[0091] According to the folding angle formula in solid geometry, we can get

[0092] cos∠DCE=cos∠QCE*cos∠DCQ

[0093] Thus we can get

[0094]

[0095] Combination Figure 2 The geometric relationship in can be further simplified as

[0096] QE=DG=Rsinθ radar

[0097] Since CG⊥DG, we have

[0098] ∠θ radar =∠DCG

[0099] It can be obtained that in the three-dimensional data acquisition model, when there is height and pitch angle, the angle of the DOA estimation output is ∠DCG. Furthermore, the coordinates of any point in the scene in the radar coordinate system can be determined, thereby solving the problem of building a three-dimensional radar data acquisition model, and by building this model, the problem of changes in the data acquisition plane when the height and pitch angle change is solved. The three-dimensional coordinates of any point D in the scene in the radar coordinate system are [DG, -GE, CE]. On this basis, further calculations can be obtained

[0100]

[0101] According to Figure 2 The geometric relationship in

[0102] CE=Hsinα+OGcosα

[0103] Using similar triangles, we can get

[0104]

[0105] in

[0106] BE=Rs-CE

[0107] The corresponding three-dimensional coordinates are In particular, the three-dimensional data acquisition model provided in this embodiment can be degenerated into a traditional two-dimensional data acquisition model if the height and pitch angle are set to zero at the same time, and the method provided in this embodiment can be applicable, that is, the method provided in this embodiment has good scalability.

[0108] S12. Determine the position information of the target to be measured relative to the radar according to the measurement parameter set.

[0109] Specifically, since the radar can only measure the moving speed of the target to be measured relative to the radar, the relative position information of the target to be measured can be determined based on the obtained measurement parameter set, so as to facilitate the subsequent conversion of the moving speed of the target to be measured based on different directions according to the position information, so as to obtain its actual moving speed in its own moving direction.

[0110] S13. Obtain, by using the radar, a relative moving speed of the target to be measured along the line of sight of the radar beam.

[0111] The relative moving speed is a three-dimensional vector. Specifically, the moving speed measured by the radar at a certain height is the relative moving speed of the target to be measured along the beam line of sight, that is, the projection of the real moving speed on the radar beam.

[0112] S14. Determine the absolute moving speed of the target to be measured along its moving direction according to the relative moving speed and the position information.

[0113] The absolute moving speed is also a three-dimensional vector. Optionally, the determining the absolute moving speed of the target to be measured along its own moving direction according to the relative moving speed and the position information at least includes: determining the absolute moving speed according to the relative moving speed, the instantaneous azimuth and instantaneous pitch angle of the target to be measured relative to the radar, that is, the position information at least includes the instantaneous azimuth and instantaneous pitch angle. Specifically, when the target to be measured is traveling on Figure 2 When the target is at point D, the measured target distance, target height difference, target horizontal angle and Figure 2 The geometric relationship in is used to determine the angle between the projection of the radar beam to the target on the ground and the projection of the radar normal on the ground (i.e., the instantaneous azimuth angle), and the angle between the radar beam to the target and the horizontal direction (i.e., the instantaneous pitch angle) is determined using the measured target distance and target height difference. Optionally, the target distance, the target height difference, the target horizontal angle, the instantaneous azimuth angle, and the instantaneous pitch angle satisfy the following relationship:

[0114]

[0115] Wherein, γ represents the instantaneous azimuth, ψ represents the instantaneous pitch angle, H represents the target height difference, R represents the target distance, θ radar represents the target horizontal angle, and asin() represents the inverse sine function.

[0116] Specifically, when the target approaches the radar, the actual measured speed will gradually decrease due to the increase in the pitch angle, and when the target moves away from the radar, the actual measured speed will gradually increase due to the decrease in the pitch angle. Therefore, if you measure the speed of a vehicle, in order to obtain the accurate driving speed of the vehicle for the judgment of traffic violations, you need to perform a three-dimensional speed conversion to convert the measured speed in the radar coordinate system to the driving coordinate system, that is, to obtain the actual driving speed of the vehicle. Figure 2 As shown, assuming that the target to be measured moves at a speed v cDriving in a direction parallel to the road, the speed along the beam line of sight measured by the radar at any time is v r , then the measured v can be converted into r Convert to v c , that is, to obtain the absolute moving speed of the target to be measured along its own moving direction.

[0117] Optional, according to Figure 2 The geometric relationship in the relative moving speed, the absolute moving speed, the instantaneous azimuth angle and the instantaneous pitch angle satisfy the following relationship:

[0118]

[0119] Among them, v c represents the absolute moving speed, v r represents the relative moving speed, γ represents the instantaneous azimuth, and ψ represents the instantaneous pitch angle. Therefore, the speed along the beam line of sight can be reversely projected to the actual driving direction, that is, converted to the driving coordinate system, and the speed in the actual driving direction is obtained, which provides an effective basis for the accurate judgment of subsequent violations.

[0120] On the basis of the above technical solution, optionally, the radar is carried on a drone, and before the absolute moving speed is determined according to the relative moving speed, the instantaneous azimuth and instantaneous pitch angle of the target to be measured relative to the radar, it also includes: obtaining the actual flight speed of the drone and the pitch angle information of the gimbal; projecting the actual flight speed to the beam line of sight direction according to the pitch angle information to obtain the projected flight speed; correspondingly, the absolute moving speed is determined according to the relative moving speed, the instantaneous azimuth and instantaneous pitch angle of the target to be measured relative to the radar, including: determining the target absolute speed of the target to be measured along the beam line of sight direction according to the relative moving speed and the projected flight speed; determining the absolute moving speed according to the target absolute speed, the instantaneous azimuth and the instantaneous pitch angle. Specifically, the method provided in this embodiment is based on the working state of arbitrary height and pitch angle, wherein the radar can be carried on a drone or on other airborne equipment mounted with the radar, and being carried on a drone can easily realize traffic supervision. When it is carried on a drone, since the drone itself can fly and move, the measurement during the flight process can be achieved by considering the speed of the drone, that is, the radar speed measurement method provided in this embodiment is suitable for dynamic models. Specifically, the actual flight speed of the drone can be synthesized first, and then the pitch angle information of the gimbal can be used to project it to the beam line of sight direction, and then the absolute speed of the target to be measured along the beam line of sight direction can be obtained by subtraction, so that the above conversion method (such as replacing v in the formula) can be used.r In addition, when the UAV is in a hovering state, the radar speed measurement method provided in this embodiment can also measure the speed of the target to be measured. At this time, the actual flight speed of the UAV is zero. Therefore, there is no need to use the pitch angle information of the gimbal to project the UAV speed to the beam line of sight direction. The target absolute speed of the target to be measured along the beam line of sight direction is directly converted according to the above conversion method (such as replacing c in the formula r Replace it with the target absolute speed) to convert it, and then get the corresponding absolute moving speed. Therefore, this method is also applicable to static models.

[0121] The technical solution provided by the embodiment of the present invention first obtains the measurement parameter set between the radar and the target to be measured, and then determines the position information of the target to be measured relative to the radar based on the measurement parameter set, and at the same time measures the relative moving speed of the target to be measured along the beam line of sight direction through the radar, thereby determining the absolute moving speed of the target to be measured along its own moving direction based on the relative moving speed and position information. By calculating the relative position information of the target to be measured, the speed conversion problem under the three-dimensional model is solved, and the speed of the target in the actual driving direction is accurately measured at any height and any pitch angle in the three-dimensional space, which makes it easier for law enforcement departments to determine and track violations.

[0122] Embodiment 2

[0123] Figure 3 This is a schematic diagram of the structure of a radar speed measurement device provided in the second embodiment of the present invention. The device can be implemented by hardware and / or software, and can generally be integrated into a radar to execute the radar speed measurement method provided in any embodiment of the present invention. Figure 3 As shown, the device comprises:

[0124] The parameter acquisition module 21 is used to obtain a set of measurement parameters between the radar and the target to be measured;

[0125] A position determination module 22, configured to determine the position information of the target to be measured relative to the radar according to the measurement parameter set;

[0126] A relative speed measurement module 23 is used to obtain the relative moving speed of the target to be measured along the beam line of sight of the radar through the radar measurement;

[0127] The absolute speed determination module 24 is used to determine the absolute moving speed of the target to be measured along its moving direction according to the relative moving speed and the position information.

[0128] The technical solution provided by the embodiment of the present invention first obtains the measurement parameter set between the radar and the target to be measured, and then determines the position information of the target to be measured relative to the radar based on the measurement parameter set, and at the same time measures the relative moving speed of the target to be measured along the beam line of sight direction through the radar, thereby determining the absolute moving speed of the target to be measured along its own moving direction based on the relative moving speed and position information. By calculating the relative position information of the target to be measured, the speed conversion problem under the three-dimensional model is solved, and the speed of the target in the actual driving direction is accurately measured at any height and any pitch angle in the three-dimensional space, which makes it easier for law enforcement departments to determine and track violations.

[0129] On the basis of the above technical solution, optionally, the parameter acquisition module 21 is specifically used for:

[0130] Obtaining a target distance, a target height difference, and a target horizontal angle between the radar and the target to be measured;

[0131] The absolute speed determination module 24 is specifically used for:

[0132] The absolute moving speed is determined according to the relative moving speed, the instantaneous azimuth angle and the instantaneous elevation angle of the target to be detected relative to the radar.

[0133] On the basis of the above technical solution, optionally, the parameter acquisition module 21 includes:

[0134] A signal transceiver unit, used to transmit a frequency modulated continuous wave signal through the radar and receive a reflected echo signal of the target to be measured;

[0135] A signal processing unit, used for performing digital down-conversion on the reflected echo signal, and arranging it into a two-dimensional matrix, and then obtaining a two-dimensional range Doppler matrix corresponding to the target to be measured by a two-dimensional fast Fourier transform;

[0136] The target distance determination unit is used to determine the target distance through a constant false alarm detection algorithm according to the two-dimensional range Doppler matrix.

[0137] On the basis of the above technical solution, optionally, the parameter acquisition module 21 includes:

[0138] A steering vector determination unit, used to determine a corresponding azimuth steering vector and a signal vector for estimating a direction of arrival according to the target distance and the target height difference;

[0139] The target horizontal angle determination unit is used to estimate the direction of arrival according to the azimuth steering vector and the signal vector to obtain the target horizontal angle.

[0140] On the basis of the above technical solution, optionally, the radar is carried on a UAV, and the parameter acquisition module 21 includes:

[0141] The target height difference measuring unit is used to measure the target height difference through the flight control system of the UAV.

[0142] On the basis of the above technical solution, optionally, the radar is carried on a UAV, and the radar speed measuring device further includes:

[0143] A flight parameter acquisition module, used for acquiring the actual flight speed of the UAV and the pitch angle information of the gimbal before determining the absolute moving speed according to the relative moving speed, the instantaneous azimuth and the instantaneous pitch angle of the target to be measured relative to the radar;

[0144] A projected flight speed determination module, used to project the actual flight speed onto the beam line of sight direction according to the pitch angle information to obtain a projected flight speed;

[0145] Accordingly, the absolute speed determination module 24 includes:

[0146] A target absolute speed determination unit, used to determine the target absolute speed of the target to be measured along the beam line of sight direction according to the relative moving speed and the projected flight speed;

[0147] The absolute speed determination unit is used to determine the absolute moving speed according to the target absolute speed, the instantaneous azimuth angle and the instantaneous pitch angle.

[0148] The radar speed measurement device provided in the embodiment of the present invention can execute the radar speed measurement method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0149] It is worth noting that in the above-mentioned embodiment of the radar speed measuring device, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0150] Embodiment 3

[0151] Figure 4 The schematic diagram of the structure of the radar provided in the third embodiment of the present invention shows a block diagram of an exemplary radar suitable for implementing the embodiments of the present invention. Figure 4 The radar shown is only an example and should not limit the functions and scope of use of the embodiments of the present invention. Figure 4As shown, the radar includes a processor 31, a memory 32, an input device 33 and an output device 34; the number of processors 31 in the radar can be one or more. Figure 4 Taking a processor 31 as an example, the processor 31, memory 32, input device 33 and output device 34 in the radar can be connected through a bus or other means. Figure 4 The example of connecting through bus is taken in the following.

[0152] The memory 32 is a computer-readable storage medium that can be used to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the radar speed measurement method in the embodiment of the present invention (for example, the parameter acquisition module 21, the position determination module 22, the relative speed measurement module 23 and the absolute speed determination module 24 in the radar speed measurement device). The processor 31 executes various functional applications and data processing of the radar by running the software programs, instructions and modules stored in the memory 32, that is, realizes the above-mentioned radar speed measurement method.

[0153] The memory 32 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and at least one application required for a function; the data storage area may store data created according to the use of the radar, etc. In addition, the memory 32 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 32 may further include a memory remotely arranged relative to the processor 31, and these remote memories may be connected to the radar via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0154] The input device 33 can be used to measure the relative moving speed of the target along the radar beam line of sight, and generate key signal input related to the user setting and function control of the radar, etc. The output device 34 can be used to feed back the measured speed data to the user, etc.

[0155] Embodiment 4

[0156] Embodiment 4 of the present invention further provides a radar speed measuring device, which includes multiple radars provided by any embodiment of the present invention, and the multiple radars are used to measure the speed of the same target to be measured to obtain the absolute moving speed of the target to be measured along its own moving direction. Specifically, multiple radars can be used to respectively apply the radar speed measuring method provided by any embodiment of the present invention to measure the speed of the same target to be measured, thereby further improving the accuracy of the measurement results. Among them, each of the multiple radars has an independent chip, and the chip model of each radar can be consistent.

[0157] Optionally, the speed measurement of the same target to be measured to obtain the absolute moving speed of the target to be measured along its own moving direction includes: multiple radars measure the speed of the same target to be measured to obtain absolute moving speed samples measured by each radar; and vector average each absolute moving speed sample to obtain the absolute moving speed. Further optionally, vector average each absolute moving speed sample to obtain the absolute moving speed includes: vector average each absolute moving speed sample to obtain a vector average speed; determine the error of each absolute moving speed sample relative to the vector average speed; if each error does not exceed a preset error, the vector average speed is used as the absolute moving speed. Alternatively, vector averaging is performed on each of the absolute moving speed samples to obtain the absolute moving speed, including: vector averaging is performed on each of the absolute moving speed samples to obtain a first vector average speed; determining the error of each of the absolute moving speed samples relative to the first vector average speed; screening out the absolute moving speed samples whose errors are greater than a preset error, and then vector averaging the remaining absolute moving speed samples to obtain a second vector average speed; and using the second vector average speed as the absolute moving speed. Specifically, when using multiple radars to measure the speed of the same target to be measured, an absolute moving speed sample of the target to be measured can be obtained by each radar, and then all the absolute moving speed samples can be vector averaged to obtain a vector average speed as the final absolute moving speed measurement result. Of course, the absolute moving speed samples with larger errors can also be first screened out, and then the remaining absolute moving speed samples can be vector averaged to obtain a vector average speed, thereby correcting the measurement result. After determining the vector average speed, the errors of each absolute moving speed sample relative to the vector average speed can also be first determined, and only when each error does not exceed the preset error, the vector average speed can be used as the final measurement result.

[0158] Embodiment 5

[0159] Embodiment 5 of the present invention further provides a radar speed measuring device, which includes multiple radars provided by any embodiment of the present invention, and the multiple radars are used to measure the speed of multiple targets to be measured to obtain the absolute moving speed of the multiple targets to be measured along their own moving directions. Specifically, multiple radars can also be used to respectively apply the radar speed measuring method provided by any embodiment of the present invention to measure the speed of multiple targets to be measured, thereby improving the speed measurement efficiency. Among them, each of the multiple radars has an independent chip, and the chip model of each radar can be consistent.

[0160] Optionally, the moving directions of the multiple targets to be measured are different from each other, that is, multiple radars can be used simultaneously to measure the speed of multiple targets to be measured with different moving directions. For example, the speed of vehicles passing by can be measured at a traffic intersection.

[0161] Embodiment 6

[0162] Embodiment 6 of the present invention further provides a server, which is used to receive the absolute moving speed of the target to be measured uploaded by the radar speed measuring device provided by any embodiment of the present invention; or, receive the absolute moving speeds of multiple targets to be measured uploaded by the radar speed measuring device provided by any embodiment of the present invention; display the absolute moving speed of the target to be measured or the multiple targets to be measured on the display screen of the server, so that the user can determine whether the target to be measured or the multiple targets to be measured are speeding.

[0163] Specifically, the server provided in this embodiment can receive the measurement results of the absolute moving speed uploaded by the radar speed measuring device provided in any embodiment of the present invention, that is, it can receive the measurement results of the radar speed measuring device for the same target to be measured, and can also receive the measurement results of the radar speed measuring device for different targets to be measured. After receiving the measurement results, the measurement results can be displayed on a display screen connected to the server so that the traffic police can view them, thereby performing statistical analysis on the measurement results, etc.

[0164] Embodiment 7

[0165] Embodiment 7 of the present invention further provides an unmanned aerial vehicle, which includes the radar speed measuring device provided by Embodiment 4 of the present invention, wherein a plurality of said radars are installed on the nose of said unmanned aerial vehicle. Specifically, when the radar speed measuring device measures the speed of the same target to be measured, only the same direction needs to be measured at the same time. At this time, the radar can be installed on the nose of the unmanned aerial vehicle to facilitate speed measurement during flight. It should be noted that when the radar is installed on the nose, the radar can be fixedly set on the nose. At this time, the unmanned aerial vehicle adjusts the flight attitude (for example, flight altitude and flight speed, etc.) according to the motion state of the target to be measured, so as to perform close tracking and speed measurement of the target to be measured, or the unmanned aerial vehicle can also directly measure the speed of the target to be measured at a distance. More preferably, the nose is provided with a gimbal, and the radar can be installed on the gimbal of the nose. At this time, the radar of the unmanned aerial vehicle can adjust the measurement range (for example, measurement angle and measurement height, etc.) as the gimbal rotates, so as to perform close or long-distance speed measurement on the target to be measured.

[0166] Embodiment 8

[0167] Embodiment 8 of the present invention further provides an unmanned aerial vehicle, which includes the radar speed measuring device provided by Embodiment 5 of the present invention, wherein a plurality of said radars are respectively installed on the nose, tail, left side and right side of the fuselage of the said unmanned aerial vehicle. Specifically, when the radar speed measuring device measures the speed of different targets to be measured, different directions may need to be measured at the same time. At this time, the radars can be respectively installed on the nose, tail, left side and right side of the fuselage of the unmanned aerial vehicle, so as to simultaneously perform coordinated speed measurement on targets to be measured in multiple directions, wherein the nose is the optimal position for setting the radar. When the radar is installed on the tail, left side and right side of the fuselage, its implementation method and principle are similar to those installed on the nose. It can be fixedly installed or rotated with a gimbal or similar product to measure the speed of the target to be measured. In order to avoid repetition of content, it will not be repeated here.

[0168] Embodiment 9

[0169] Embodiment 9 of the present invention further provides a storage medium containing computer executable instructions, and when the computer executable instructions are executed by a computer processor, they are used to execute a radar speed measurement method, the method comprising:

[0170] Obtaining a measurement parameter set between the radar and the target to be measured;

[0171] Determine the position information of the target to be measured relative to the radar according to the measurement parameter set;

[0172] The relative moving speed of the target to be measured along the line of sight of the radar beam is obtained by measuring the radar;

[0173] The absolute moving speed of the target to be measured along its moving direction is determined according to the relative moving speed and the position information.

[0174] The storage medium may be any of various types of memory devices or storage devices. The term "storage medium" is intended to include: installation media, such as CD-ROM, floppy disk or tape device; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (such as hard disk or optical storage); registers or other similar types of memory elements, etc. The storage medium may also include other types of memory or combinations thereof. In addition, the storage medium may be located in the computer system in which the program is executed, or may be located in a different second computer system, which is connected to the computer system via a network (such as the Internet). The second computer system may provide program instructions to the computer for execution. The term "storage medium" may include two or more storage media that may reside in different locations (e.g., in different computer systems connected via a network). The storage medium may store program instructions (e.g., embodied as a computer program) that may be executed by one or more processors.

[0175] Of course, the computer executable instructions of a storage medium including computer executable instructions provided in an embodiment of the present invention are not limited to the operations of the method described above, but can also execute related operations in the radar speed measurement method provided in any embodiment of the present invention.

[0176] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0177] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0178] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for an electronic device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0179] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A radar speed measurement method, It is characterized in that include: Acquire a measurement parameter set between the radar and the target to be measured, wherein the measurement parameter set at least includes three-dimensional data between the radar and the target to be measured; Determine the position information of the target to be measured relative to the radar according to the measurement parameter set; The relative moving speed of the target to be measured along the line of sight of the radar beam is obtained by measuring the radar, wherein the relative moving speed is a three-dimensional vector; The absolute moving speed of the target to be measured along its moving direction is determined according to the relative moving speed and the position information, and the absolute moving speed is a three-dimensional vector.

2. The radar speed measurement method according to claim 1, It is characterized in that The three-dimensional data includes: obtaining a target distance, a target height difference and a target horizontal angle between the radar and the target to be measured; The step of determining the absolute moving speed of the target to be measured along its moving direction according to the relative moving speed and the position information at least comprises: The absolute moving speed is determined according to the relative moving speed, the instantaneous azimuth angle and the instantaneous elevation angle of the target to be detected relative to the radar.

3. The radar speed measurement method according to claim 2, It is characterized in that The obtaining of the target distance between the radar and the target to be measured includes: Transmitting a frequency modulated continuous wave signal through the radar and receiving a reflected echo signal of the target to be measured; Performing digital down-conversion on the reflected echo signal and sorting it into a two-dimensional matrix, and then obtaining a two-dimensional range Doppler matrix corresponding to the target to be measured by a two-dimensional fast Fourier transform; The target distance is determined by a constant false alarm detection algorithm according to the two-dimensional range Doppler matrix.

4. The radar speed measurement method according to claim 2, It is characterized in that The step of obtaining a target horizontal angle between the radar and the target to be measured comprises: Determine a corresponding azimuth guidance vector and a signal vector for estimating a direction of arrival according to the target distance and the target height difference; The direction of arrival is estimated according to the azimuth steering vector and the signal vector to obtain the target horizontal angle.

5. The radar speed measurement method according to claim 2, It is characterized in that The radar is carried on a drone, and obtaining the target height difference between the radar and the target to be measured includes: The target height difference is measured by the flight control system of the UAV.

6. The radar speed measurement method according to any one of claims 2 to 5, It is characterized in that The radar is carried on a drone, and before determining the absolute moving speed according to the relative moving speed, the instantaneous azimuth angle and the instantaneous pitch angle of the target to be measured relative to the radar, the method further includes: Obtaining the actual flight speed of the drone and the pitch angle information of the gimbal; Projecting the actual flight speed onto the beam line of sight direction according to the pitch angle information to obtain a projected flight speed; Correspondingly, determining the absolute moving speed according to the relative moving speed, the instantaneous azimuth angle and the instantaneous pitch angle of the target to be measured relative to the radar includes: Determine the target absolute speed of the target to be measured along the beam line of sight direction according to the relative moving speed and the projected flight speed; The absolute moving speed is determined according to the target absolute speed, the instantaneous azimuth angle, and the instantaneous pitch angle.

7. The radar speed measurement method according to claim 6, It is characterized in that The target distance, the target height difference, the target horizontal angle, the instantaneous azimuth angle, and the instantaneous pitch angle satisfy the following relationship: Wherein, γ represents the instantaneous azimuth, ψ represents the instantaneous pitch angle, H represents the target height difference, R represents the target distance, θ radar represents the target horizontal angle, and asin() represents the inverse sine function.

8. The radar speed measurement method according to claim 6, It is characterized in that The relative moving speed, the absolute moving speed, the instantaneous azimuth angle, and the instantaneous pitch angle satisfy the following relationship: Among them, v c represents the absolute moving speed, v r represents the relative moving speed, γ represents the instantaneous azimuth angle, and ψ represents the instantaneous pitch angle.

9. A radar, It is characterized in that include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the radar speed measurement method as described in any one of claims 1-8.

10. A radar speed measuring device, It is characterized in that It comprises a plurality of radars as claimed in claim 9, wherein the plurality of radars are used to measure the speed of the same target to be measured, so as to obtain the absolute moving speed of the target to be measured along its own moving direction.

11. The radar speed measuring device according to claim 10, It is characterized in that The method of measuring the speed of the same target to be measured to obtain the absolute moving speed of the target to be measured along its moving direction includes: The multiple radars measure the speed of the same target to be measured to obtain absolute moving speed samples measured by each radar; Vector averaging is performed on each of the absolute moving speed samples to obtain the absolute moving speed.

12. The radar speed measuring device according to claim 11, It is characterized in that Performing vector averaging on each of the absolute moving speed samples to obtain the absolute moving speed comprises: Performing vector averaging on each of the absolute moving speed samples to obtain a vector average speed; determining an error of each of the absolute moving velocity samples relative to the vector average velocity; If each of the errors does not exceed a preset error, the vector average speed is used as the absolute moving speed.

13. The radar speed measuring device according to claim 11, It is characterized in that Performing vector averaging on each of the absolute moving speed samples to obtain the absolute moving speed comprises: Performing vector averaging on each of the absolute moving speed samples to obtain a first vector average speed; determining an error of each of the absolute moving speed samples relative to the first vector average speed; The absolute moving speed samples whose errors are greater than a preset error are screened out, and then the remaining absolute moving speed samples are vector averaged to obtain a second vector average speed; The second vector average speed is used as the absolute moving speed.

14. A radar speed measuring device, It is characterized in that It comprises a plurality of radars as claimed in claim 9, wherein the plurality of radars are used to measure the speed of a plurality of targets to be measured, so as to obtain the absolute moving speed of the plurality of targets to be measured along their own moving directions.

15. The radar speed measuring device according to claim 14, It is characterized in that The moving directions of the multiple targets to be detected are different from each other.

16. A server, It is characterized in that The server is used to: Receiving the absolute moving speed of the target to be measured uploaded by the radar speed measuring device according to any one of claims 10 to 13; Or, receiving the absolute moving speeds of the multiple targets to be measured uploaded by the radar speed measuring device according to any one of claims 14 to 15; The absolute moving speed of the target to be measured or the multiple targets to be measured is displayed on the display screen of the server, so that the user can determine whether the target to be measured or the multiple targets to be measured are speeding.

17. A drone, It is characterized in that It comprises the radar speed measuring device as described in any one of claims 10 to 13, wherein a plurality of the radars are installed on the nose of the drone.

18. The drone according to claim 17, It is characterized in that The nose of the aircraft is provided with a pan-tilt platform, and the radar is installed on the pan-tilt platform.

19. A drone, It is characterized in that It comprises the radar speed measuring device as described in any one of claims 14 to 15, wherein a plurality of said radars are respectively installed on the nose, tail, left side and right side of the fuselage of the unmanned aerial vehicle.

20. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the program is executed by a processor, the radar speed measurement method as described in any one of claims 1 to 8 is implemented.

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