Radar speed measurement calibration system and calibration method

Abstract

The embodiment of the invention discloses a radar speed measurement calibration system and calibration method. The calibration method comprises the following steps: carrying out two-dimensional scanning on the side surface of the rotating turntable by adopting a speed measuring radar, and transmitting and collecting a test signal in real time. The turntable rotates at a stable rotating speed. Reflected signals are processed, and test data nephograms of different positions of the side face of the turntable are generated. According to the diameter and the rotating speed of the turntable, the component velocity of each position on the side surface in the signal propagation direction is calculated, and the actual conversion coefficient between the test data and the velocity on the test data cloud picture is calibrated accordingly. According to the radar speed measurement calibration system and calibration method provided by the embodiment of the invention, the problem that a traditional speed calibration method needs multiple times of calibration is solved, and speed calibration is completed at one time by scanning the test data cloud picture, so that the calibration efficiency is remarkably improved, and the accuracy and stability of radar speed measurement are ensured.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of radar calibration technology, and in particular to a radar speed measurement calibration system and a calibration method. Background Art

[0002] Speed ​​calibration refers to the calibration of the radar system through a series of standard procedures and methods to ensure that it can accurately and reliably measure the speed of an object.

[0003] In the prior art, rotational calibration is to calibrate the speed of the rotating object surface by radar. Compared with translational speed calibration, rotational speed calibration requires less space. However, in the existing rotational calibration process, in order to obtain calibration points with different speeds, multiple calibrations are often required, and the calibration process is cumbersome. Summary of the invention

[0004] The present invention provides a radar speed measurement calibration system and calibration method, by scanning the test data cloud Figure 1 The speed calibration is completed in one go, which significantly improves the calibration efficiency and ensures the accuracy and stability of radar speed measurement.

[0005] In a first aspect, an embodiment of the present invention provides a radar speed measurement calibration system, including a speed measurement radar, a turntable, and a processor;

[0006] The turntable is used to rotate at a steady speed;

[0007] The speed measuring radar is used to transmit test signals to different positions on the side of the rotating turntable in a two-dimensional scanning manner, and collect the test signals reflected by different positions on the side of the turntable in real time; it is also used to process the reflected test signals and determine the test data cloud map at different positions on the side of the turntable;

[0008] The processor is used to calculate the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal based on the diameter and stable rotation speed of the turntable; it is also used to calibrate the actual conversion coefficient between the test data and the speed on the test data cloud map based on the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal.

[0009] Optionally, the radar speed measurement calibration system also includes a rotational speed measurement module, which is used to measure the stable rotational speed of the turntable.

[0010] Optionally, the processor is further configured to use the calibrated actual conversion system to correct the original conversion coefficient between the test data and the speed.

[0011] In a second aspect, an embodiment of the present invention further provides a radar speed measurement calibration method, which is applied to a radar speed measurement calibration system as described in any one of the first aspects, and the calibration method includes:

[0012] The speed measuring radar is used to transmit test signals to different positions on the side of the rotating turntable in a two-dimensional scanning manner, and the test signals reflected by different positions on the side of the turntable are collected in real time; the turntable rotates at a stable speed;

[0013] Perform data processing on the reflected test signal to determine the test data cloud diagram at different positions on the side of the turntable;

[0014] According to the diameter and stable rotation speed of the turntable, the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal are calculated;

[0015] According to the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal, the actual conversion coefficient between the test data and the velocity on the test data cloud diagram is calibrated.

[0016] Optionally, before calculating the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter and the stable rotation speed of the turntable, the method further includes:

[0017] Measure the steady speed of the rotating disk.

[0018] Optionally, data processing is performed on the reflected test signal to determine the test data cloud diagram at different positions on the side of the turntable, including:

[0019] According to the propagation direction of the test signal emitted by the speed measuring radar during the scanning process in space and the relative position to the turntable, the coordinates of different positions on the side of the turntable reflecting the test signal are determined;

[0020] The coordinates of different positions on the side of the turntable that reflect the test signal are used to draw a cloud diagram of the test data at different positions on the side of the turntable.

[0021] Optionally, data processing is performed on the reflected test signal to determine the test data cloud diagram at different positions on the side of the turntable, including:

[0022] Performing interference beat frequency on the reflected test signal and the local oscillator signal corresponding to the test signal to obtain a beat frequency signal;

[0023] Calculate the difference frequency data of the test signal reflected at different positions on the side of the turntable according to the beat frequency signal;

[0024] By using the different positions on the side of the turntable and their corresponding difference frequency data, a cloud diagram of the difference frequency data at different positions on the side of the turntable is drawn.

[0025] Optionally, according to the diameter and the stable rotation speed of the turntable, the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal are calculated, including:

[0026] According to the diameter and stable rotation speed of the turntable, calculate the tangential velocity at any position on the side of the turntable;

[0027] According to the tangential velocity at any position on the side of the turntable and the propagation direction of the test signal corresponding to different positions on the side of the turntable that reflects the test signal, the component velocity of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal is calculated.

[0028] Optionally, according to the diameter and the stable rotation speed of the turntable, the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal are calculated, including:

[0029] According to the diameter and stable rotation speed of the turntable, calculate the tangential velocity at any position on the side of the turntable;

[0030] The propagation direction of the test signal is approximated as the first direction, and the component velocity of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal is calculated based on the tangential velocity at any position on the side of the turntable; wherein the first direction is the propagation direction of the test signal passing through the center of the turntable.

[0031] Optionally, after calibrating the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal, the method further includes:

[0032] The original conversion coefficient between the test data and the speed is corrected by using the calibrated actual conversion system.

[0033] The embodiment of the present invention provides a radar speed measurement calibration system and calibration method, which solves the problem that the traditional speed calibration method requires multiple calibrations. Figure 1 The speed calibration is completed in one go, which significantly improves the calibration efficiency and ensures the accuracy and stability of radar speed measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a radar speed measurement calibration system provided by an embodiment of the present invention;

[0035] Figure 2 is a flow chart of a radar speed measurement calibration method provided by an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of a test data cloud diagram of a radar speed measurement calibration system provided by an embodiment of the present invention;

[0037] Figure 4 is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention;

[0038] Figure 5 is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention;

[0039] Figure 6 is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention;

[0040] Figure 7 is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention;

[0041] Figure 8 This is another speed component calculation principle diagram provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is 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 are shown in the accompanying drawings, rather than all structures.

[0043] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. It should be noted that the "upper", "lower", "left" and "right" directional words described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first" and "second" are used for descriptive purposes only and do not indicate any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention are understood in specific circumstances.

[0044] The term “including” and its variations used in the present invention are open inclusions, that is, “including but not limited to.” The term “based on” means “based at least in part on.” The term “one embodiment” means “at least one embodiment.”

[0045] It should be noted that the concepts of “first” and “second” mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or interdependence.

[0046] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0047] Figure 1 FIG. 1 is a schematic diagram of a radar speed measurement calibration system provided by an embodiment of the present invention. Figure 1 As shown, the radar speed measurement calibration system includes a speed measurement radar 10, a turntable 11 and a processor 12.

[0048] The turntable 11 is used to rotate at a stable speed. The turntable 11 can be understood as a rotating target with a certain thickness and can rotate stably; the stable speed can be understood as a preset adjustable speed to be tested, and the stable speeds of the same test data point cloud are the same, but according to the measurement requirements, radar models, uses, etc., the stable speed can be adjusted and preset in the turntable.

[0049] The speed measuring radar 10 is used to transmit test signals to different positions on the side of the rotating turntable 11 in a two-dimensional scanning manner, and to collect test signals reflected by different positions on the side of the turntable 11 in real time; it is also used to process the reflected test signals to determine the test data cloud map at different positions on the side of the turntable 11. Among them, the speed measuring radar 10 can be understood as a Doppler radar, which includes a scanning system. Two-dimensional scanning can be understood as scanning of the radar in the horizontal and vertical directions in the test direction to obtain information such as the position and speed of the target object. The test signal can be understood as the original signal emitted by the Doppler radar, and the frequency f of the signal u It is generally defined as the upstream frequency or the transmit frequency. The reflected test signal can be understood as the frequency of the signal reflected from the moving target (such as the turntable 11) received by the radar. The frequency of the signal f d It is generally defined as the downstream frequency or received frequency. Due to the Doppler effect, the reflected frequency may be different from the original transmitted frequency due to the movement of the target.

[0050] The processor 12 is used to calculate the component speed of different positions on the side of the turntable 11 that reflects the test signal in the propagation direction of the test signal according to the diameter and stable rotation speed of the turntable 11; it is also used to calibrate the actual conversion coefficient between the test data and the speed on the test data cloud map according to the component speed of different positions on the side of the turntable 11 that reflects the test signal in the propagation direction of the test signal. Among them, the component speed refers to the speed component of an object in a specific direction. In this embodiment, the component speed refers to the speed component of different positions on the side of the turntable 11 in the propagation direction of the test signal. The actual conversion coefficient can be understood as the coefficient required to convert the test data into the actual speed value.

[0051] Specifically, the radar to be calibrated sends a test signal to the target position to be calibrated in sequence through its own scanning system, and calculates the theoretical speed of the target position to be calibrated based on the received reflected signal and the frequency shift of the test signal. The processor 12 calculates the actual speed of the target position to be calibrated based on the diameter d of the turntable 11, the stable rotation speed, the distance L between the turntable 11 and the radar, the speed measurement signal, and the angle α between the center of the radar and the turntable 11. The actual conversion coefficient is determined by the corresponding relationship between the actual speed and the theoretical speed.

[0052] The technical solution of this embodiment is as follows: first, the turntable 11 rotates at a stable speed, and different positions on the side of the turntable 11 have different speed components compared to the direction of the test signal, thereby providing multiple test points with different speeds for radar speed measurement; then, the speed measuring radar 10 transmits test signals to different positions on the side of the turntable 11 in a two-dimensional scanning manner, and collects reflected signals in real time to form a test data cloud map; finally, the processor 12 calculates the component speeds of different positions on the side of the turntable 11 in the direction of propagation of the test signal based on the diameter of the turntable 11, the stable speed, and the geometric relationship between the radar and the turntable 11, and calibrates the actual conversion coefficient between the test data and the speed on the test data cloud map accordingly. Through this method, only the test data cloud map needs to be scanned. Figure 1 Speed ​​calibration can be completed in one step, which significantly improves the calibration efficiency and ensures the accuracy and stability of radar speed measurement.

[0053] Optionally, the radar speed measurement calibration system further includes a rotation speed measurement module, which is used to measure the stable rotation speed of the turntable 11.

[0054] The speed measuring module can be understood as an instrument for measuring the speed of a rotating object (such as a turntable 11). In this system, the speed measuring module is used to measure the stable speed of the turntable 11 and provide necessary input data for the processor 12. The speed measuring module can be any speed sensor or a structure with a speed measurement function, which is not limited in the embodiment of the present invention.

[0055] Specifically, the angular velocity of the turntable 11 is obtained through the rotation speed measurement module, and the linear velocity of the turntable 11 , that is, the stable rotation speed, is obtained through the angular velocity and the diameter d of the turntable 11 .

[0056] Optionally, the processor 12 is further configured to use the calibrated actual conversion system to correct the original conversion coefficient between the test data and the speed.

[0057] The calibrated actual conversion system can be understood as a radar system that has been speed calibrated.

[0058] Specifically, for a radar system that has been speed calibrated, a test signal is sent to the turntable through the scanning system, and the calibrated speed of the target position to be calibrated is calculated based on the received reflected signal, the frequency shift of the test signal and the calibrated original conversion coefficient. The correction coefficient is generated through the correspondence between the actual speed and the calibrated speed, and the original conversion coefficient is adjusted.

[0059] Figure 2 is a flow chart of a radar speed measurement calibration method provided by an embodiment of the present invention. Figure 3 1 is a schematic diagram of a test data cloud diagram of a radar speed measurement calibration system provided by an embodiment of the present invention. Figure 2 As shown, the radar speed measurement calibration method can be applied to the radar speed measurement calibration system of any one of the first aspects, and the calibration method includes:

[0060] S110, the turntable rotates at a stable speed.

[0061] Specifically, the turntable rotates at a preset stable speed, which can be preset and built into the turntable according to measurement requirements, radar models, uses, etc. Different positions on the side of the turntable have different speed components, thus providing multiple test points with different speeds for radar speed measurement.

[0062] S120. Use a speed measuring radar to transmit test signals to different positions on the side of the rotating turntable in a two-dimensional scanning manner, and collect test signals reflected by different positions on the side of the turntable in real time.

[0063] Specifically, the speed radar transmits test signals to the scanning area on the side of the turntable in a two-dimensional scanning manner, in the order of rows or columns, and collects reflected signals in real time. If the speed radar itself does not have a scanning function, two-dimensional scanning can be performed by an external scanning device.

[0064] S130, performing data processing on the reflected test signal to determine the test data cloud diagrams at different positions on the side of the turntable.

[0065] Specifically, the radar receives the test signal reflected from different positions on the side of the turntable and pre-processes it (such as filtering, denoising, etc.) to improve the signal quality. Then, according to the frequency f of the transmitted signal u and the frequency f of the reflected signal d , calculate the difference frequency Δf = f u -f d The projection of the turntable side position (x, y, z) on the two-dimensional scanning plane is recorded in the form of cloud coordinates (x, z), and the test data related to the cloud coordinates (such as λ·Δf / 2) is calculated.

[0066] For example, Figure 3As shown, the wavelength of the test signal is λ and the frequency of the test signal is f u , the frequency of the reflected test signal is f d , the conversion coefficient is k, the fixed frequency deviation caused by the system is b, and the theoretical speed of the test signal is v = b + k * λ * (f u -f d ) / 2, each point in the test data cloud map includes the cloud map coordinates (x, z) and the processed test data λ*(f u -f d ) / 2, all points on the test data cloud map together constitute the test data cloud map.

[0067] S140, calculating the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter and the stable rotation speed of the turntable.

[0068] Specifically, the geometric relationship between the turntable and the radar is confirmed according to the preset calibration settings, the linear velocity of the turntable is calculated, the radar scanning direction vector is determined, and the velocity component of the turntable linear velocity in the direction of the radar test signal is calculated.

[0069] For example, Figure 1 As shown, it is assumed that the radar and the position of the reflected test signal on the turntable are on the same horizontal plane, the radar coordinates are (0, 0) opposite the center of the circle (0, L+r), the radius of the circle is r=d / 2, the distance from the radar to the center of the circle is L+r, the line connecting the radar to the center of the circle passes through the point (0, L) on the circle, the angular velocity of the turntable is ω, and the radar scans the turntable in scanning mode. When the radar scans any point (x, y) on the turntable, the linear velocity of any point P(x, y) on the turntable is It can be expressed as: in is the position vector from the center of the circle O(0, L+r) to point P: Radar scan direction vector: The cosine of the angle required for the velocity component Velocity components:

[0070] S150, calibrating the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds at different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal.

[0071] Among them, the actual conversion coefficient can be understood as the mathematical proportional factor or coefficient used to convert the reflected signal received by the test equipment (such as the frequency change in Doppler speed measurement) into the actual speed of the object under test (such as the side of a turntable) in the direction of propagation of the test signal under specific test conditions.

[0072] Specifically, the cloud coordinates (x, z) of each test point and the corresponding test data, such as λ·Δf / 2, are extracted from the test data cloud map. u and the frequency f of the reflected signal d , difference frequency Δf=f u -f d . Calculate the velocity component v based on the turntable side coordinates (x, y, z) obtained by radar scanning scan , according to v scan = k*λ*(f u -f d ) / 2, and then the actual conversion coefficient k1-kn corresponding to each turntable side coordinate is obtained, and the optimal value of the actual conversion coefficient k is solved by the least square method or other optimization algorithms.

[0073] Embodiments of the present invention The embodiments of the present invention first provide a plurality of test points with different speeds for the speed measuring radar by setting a turntable rotating at a preset stable speed. Secondly, the speed measuring radar obtains the speed information of each position on the side of the turntable in a two-dimensional scanning manner. Finally, the component speeds of different positions on the side of the turntable in the propagation direction of the test signal are calculated, and the actual conversion coefficient between the test data and the speed on the test data cloud map is calibrated, thereby achieving accurate conversion between the test data and the speed, improving the problems of inaccurate speed measurement and complex calibration that may exist in the traditional radar speed measurement method, and improving the accuracy and reliability of the speed measurement.

[0074] Optionally, the refinement process of the above embodiment can be further limited. In the above embodiment, after S150, according to the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal, the actual conversion coefficient between the test data and the speed on the test data cloud map is calibrated, it also includes: using the calibrated actual conversion system to correct the original conversion coefficient between the test data and the speed.

[0075] Specifically, it can be:

[0076] S160. Using the calibrated actual conversion system, correct the original conversion coefficient between the test data and the speed.

[0077] Specifically, for a calibrated speed radar, a test signal is sent to different positions on the side of the turntable, and the reflected signal is received. The calibrated speed at each position on the side of the turntable is calculated based on the frequency shift of the reflected signal and the calibrated original conversion coefficient. Based on the corresponding relationship between the actual speed and the calibrated speed, a correction coefficient is generated, which is used to adjust the original conversion coefficient to more accurately reflect the actual relationship between the test data and the speed.

[0078] Optionally, the refinement process of the above embodiment can be further limited. In the above embodiment, before calculating the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal in S140 according to the diameter and stable rotation speed of the turntable, it also includes: measuring the stable rotation speed of the turntable in the rotating state. Specifically, it can be:

[0079] S139, measuring the stable rotation speed of the turntable in the rotating state.

[0080] Specifically, the stable speed of the turntable in a rotating state can be obtained by using a speed measuring device such as a Hall sensor to avoid a difference between a preset speed and an actual speed, thereby preventing inaccurate calibration.

[0081] Figure 4 : is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention. The embodiment of the present invention refines or optimizes the above embodiment. Specifically, in S130 of the above embodiment, data processing is performed on the reflected test signal to determine the test data cloud map at different positions on the side of the turntable, which can be specifically refined as follows:

[0082] According to the propagation direction of the test signal emitted by the speed measuring radar during the scanning process in space and the relative position to the turntable, the coordinates of different positions on the side of the turntable reflecting the test signal are determined;

[0083] The coordinates of different positions on the side of the turntable that reflect the test signal are used to draw a cloud diagram of the test data at different positions on the side of the turntable.

[0084] like Figure 4 As shown, the method may specifically include the following steps:

[0085] S210, the turntable rotates at a stable speed.

[0086] S220, using a speed measuring radar, transmitting test signals to different positions on the side of the rotating turntable in a two-dimensional scanning manner, and collecting the test signals reflected by different positions on the side of the turntable in real time.

[0087] S230. Determine the coordinates of different positions on the side of the turntable that reflect the test signal according to the propagation direction of the test signal emitted by the speed measuring radar during the scanning process in space and the relative position to the turntable.

[0088] Specifically, during the radar scanning process, the scanning system scans the surface of the object to be measured (i.e., the turntable) at a fixed angle. Whenever a position on the side of the turntable is scanned, the radar calculates the distance between the radar and the object to be measured based on the frequency difference between the reflected test signal and the test signal. Based on the rotation angle of the radar and the distance between the radar and the target object, the coordinates (x, y, z) of different positions on the side of the turntable in three-dimensional space can be obtained, with the line from the radar to the center of the disk as the y-axis, the direction perpendicular to the y-axis in the horizontal direction as the x-axis, and the direction of the horizontal plane perpendicular to the x-axis and y-axis as the z-axis.

[0089] S240 , using the coordinates of different positions on the side of the turntable that reflect the test signal, draw a cloud diagram of test data obtained at different positions on the side of the turntable.

[0090] Specifically, the projection coordinates on the two-dimensional plane (x, z) are calculated through the coordinates (x, y, z) of different positions on the side of the turntable in three-dimensional space, the projection coordinates, the test signal and its corresponding reflected test signal are recorded accordingly, and a test data cloud diagram of different positions on the side of the turntable is drawn.

[0091] S250, calculating the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter and the stable rotation speed of the turntable.

[0092] S260, calibrating the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds at different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal.

[0093] In the embodiment of the present invention, the propagation direction of the test signal emitted by the radar during the scanning process in space and the corresponding frequency difference data are converted into direction and distance, thereby obtaining the three-dimensional coordinates of different positions on the side of the turntable. Then, by projecting the three-dimensional coordinates onto a two-dimensional plane and drawing a cloud map, the test signal, the reflected signal and the side position of the turntable are displayed in an intuitive manner, and a data basis is provided for subsequent speed calibration.

[0094] Figure 5 It is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention. The embodiment of the present invention refines or optimizes the above embodiment. Specifically, S130 in the above embodiment, data processing is performed on the reflected test signal to determine the test data cloud map at different positions on the side of the turntable. It can be specifically refined as follows: the reflected test signal is interfered with the local oscillator signal corresponding to the test signal to obtain a beat frequency signal; based on the beat frequency signal, the difference frequency data of the test signal reflected at different positions on the side of the turntable are calculated; and the difference frequency data corresponding to the different positions on the side of the turntable and the corresponding difference frequency data are used to draw a cloud map of the difference frequency data at different positions on the side of the turntable.

[0095] like Figure 5 As shown, the method may specifically include the following steps:

[0096] S310, the turntable rotates at a stable speed.

[0097] S320, using a speed measuring radar, in a two-dimensional scanning manner, to transmit test signals to different positions on the side of the rotating turntable, and to collect test signals reflected by different positions on the side of the turntable in real time.

[0098] S330 , perform interference beat frequency on the reflected test signal and the local oscillator signal corresponding to the test signal to obtain a beat frequency signal.

[0099] Specifically, the test signal is transmitted on the local oscillator signal. In order to accurately obtain the frequency difference between the reflected test signal and the test signal, the reflected test signal can be obtained by interfering with the local oscillator signal corresponding to the test signal. For example, if the local oscillator signal frequency is f 本振 , the frequency of the transmitted signal is f 发射 , the reflected test signal frequency is f 反射 , the frequency of the beat signal is f 拍频 , assuming that the above signals have a simple linear relationship. At this time, the frequency f of the transmitted signal is known 发射 , the frequency f of the array signal 本振 According to the principle of interference beat frequency, f 拍频 =f 反射 -f 本振 .

[0100] S340. Calculate the difference frequency data of the test signal reflected at different positions on the side of the turntable according to the beat frequency signal.

[0101] Specifically, according to the frequency of the transmitted signal and the frequency of the beat frequency signal, the difference frequency data corresponding to the test signal reflected at different positions on the side of the turntable is calculated, which provides a data basis for the subsequent calculation of the theoretical speed at different positions on the side of the turntable based on the difference frequency data, which helps to improve the accuracy and reliability of the entire radar speed measurement calibration system and ensure that the measurement results can truly reflect the actual motion state of the turntable. For example, if the local oscillator signal frequency is f 本振 , the frequency of the transmitted signal is f 发射 , the reflected test signal frequency is f 反射 , the frequency of the beat signal is f 拍频 , assuming that the above signals have a simple linear relationship. In this case, f 反射 =f 本振 +f 拍频 , difference frequency Δf=f 反射 -f 发射 .

[0102] S350, using different positions on the side of the turntable and their corresponding difference frequency data, draw a cloud diagram of the difference frequency data at different positions on the side of the turntable.

[0103] Specifically, the different positions on the side of the turntable and their corresponding difference frequency data are recorded, and a cloud diagram of the difference frequency data at different positions on the side of the turntable is drawn. Figure 3 As shown in the figure, in the difference frequency data cloud map, each data point represents a specific position on the side of the turntable, and the properties of the data point (such as color, grayscale, etc.) are determined by the difference frequency data value at that position. For example, the position with a larger difference frequency data may be represented by a darker color in the cloud map, and the position with a smaller difference frequency data may be represented by a lighter color.

[0104] S360. Calculate the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal according to the diameter and the stable rotation speed of the turntable.

[0105] S370, calibrating the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds at different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal.

[0106] In the embodiment of the present invention, the reflected test signal is firstly interfered with the local oscillator signal to obtain a beat frequency signal, thereby effectively separating and extracting information related to the reflected test signal. Then, the difference frequency is calculated by the beat frequency signal to reduce the influence of the measurement error on the result. Finally, the difference frequency and its corresponding position are recorded on the difference frequency data cloud map, providing a data basis for subsequent speed calibration.

[0107] Figure 6 It is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention. The embodiment of the present invention refines or optimizes the above embodiment. Specifically, S140 in the above embodiment, calculating the component speed of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal according to the diameter and the stable rotation speed of the turntable, can be specifically refined as follows: calculating the tangential speed at any position on the side of the turntable according to the diameter and the stable rotation speed of the turntable; calculating the component speed of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal according to the tangential speed at any position on the side of the turntable and the propagation direction of the test signal corresponding to different positions on the side of the turntable that reflects the test signal.

[0108] like Figure 6 As shown, the method may specifically include the following steps:

[0109] S410, the turntable rotates at a stable speed.

[0110] S420, using a speed measuring radar, in a two-dimensional scanning manner, to transmit test signals to different positions on the side of the rotating turntable, and to collect test signals reflected by different positions on the side of the turntable in real time.

[0111] S430, performing data processing on the reflected test signal to determine the test data cloud diagrams at different positions on the side of the turntable.

[0112] S440: Calculate the tangential velocity at any position on the side of the turntable according to the diameter and the stable rotation speed of the turntable.

[0113] Specifically, according to the diameter and stable speed of the turntable, the linear velocity of any point P(x,y) on the turntable is It can be expressed as: in, It is the position vector from the center O to any position on the side of the turntable.

[0114] S450. Calculate the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal based on the tangential velocity at any position on the side of the turntable and the propagation direction of the test signal corresponding to different positions on the side of the turntable that reflects the test signal.

[0115] Specifically, when the radar scans any point (x, y, z) on the turntable, the radar scanning direction vector is: The cosine of the angle required for the velocity component Velocity components:

[0116] S460, calibrating the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds at different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal.

[0117] In the embodiment of the present invention, the tangential velocity at any position on the side of the turntable is calculated by the diameter and stable rotation speed of the turntable. Then, the cosine value of the angle between the radar scanning direction vector and the tangential vector at the corresponding position on the turntable is calculated, and finally the component velocity of the turntable rotation speed in the propagation direction of the test signal, that is, the actual velocity, is calculated.

[0118] Figure 7 is a flow chart of another radar speed measurement calibration method provided by an embodiment of the present invention. Figure 8It is another speed component calculation principle diagram provided by an embodiment of the present invention. The embodiment of the present invention refines or optimizes the above embodiment. Specifically, the above embodiment S140, which calculates the speed component of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal according to the diameter and stable rotation speed of the turntable, can be specifically refined as follows: according to the diameter and stable rotation speed of the turntable, calculate the tangential speed at any position on the side of the turntable; the propagation direction of the test signal is approximated to the first direction, and according to the tangential speed at any position on the side of the turntable, calculate the speed component of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal; wherein the first direction is the propagation direction of the test signal passing through the center of the turntable.

[0119] like Figure 7 As shown, the method may specifically include the following steps:

[0120] S510, the turntable rotates at a stable speed.

[0121] S520, using a speed measuring radar, in a two-dimensional scanning manner, to transmit test signals to different positions on the side of the rotating turntable, and to collect test signals reflected by different positions on the side of the turntable in real time.

[0122] S530: Process the reflected test signal to determine the test data cloud diagrams at different positions on the side of the turntable.

[0123] S540: Calculate the tangential velocity at any position on the side of the turntable according to the diameter and the stable rotation speed of the turntable.

[0124] Specifically, according to the diameter and stable speed of the turntable, the linear velocity of any point P(x,y) on the turntable is It can be expressed as: in, It is the position vector from the center O to any position on the side of the turntable.

[0125] S550. Approximate the propagation direction of the test signal to the first direction, and calculate the component velocity of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal based on the tangential velocity at any position on the side of the turntable; wherein the first direction is the propagation direction of the test signal passing through the center of the turntable.

[0126] Specifically, the propagation direction of the test signal passing through the center of the turntable is taken as the first direction. Since the distance L between the turntable and the speed measuring radar is much larger than the turntable radius d / 2, the included angle between the propagation direction of the test signal and the first direction is cosβ≈1. Therefore, in order to simplify the calculation, the propagation direction of the test signal can be approximated as the first direction. For example, Figure 8As shown, it is assumed that the speed radar and the position of the reflected test signal on the turntable are on the same horizontal plane, the speed radar is located at the coordinates (0, 0) facing the center of the turntable (0, L+r), the radius of the circle is r=d / 2, the distance from the speed radar to the center of the turntable is L+r, the first direction is the direction from the speed radar to the center of the turntable, the test signal along the first direction is reflected at the point (0, L) on the disk, the angular velocity of the turntable is ω, the radar scans the turntable in scanning mode, when the speed radar scans to any point (x, y) on the turntable, the linear velocity of any point P(x, y) on the turntable It can be expressed as: in, is the position vector from the center of the turntable O(L+r,0) to point P: The scanning direction of the speed radar is approximately the first direction cosα=(r-y+L) / r, and the velocity component is:

[0127] S560, calibrate the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds at different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal.

[0128] In the embodiment of the present invention, the tangential velocity at any position on the side of the turntable is calculated according to the diameter and the stable rotation speed of the turntable, which provides key intermediate data for the subsequent calculation of the component velocity of the reflected test signal in the propagation direction. Then, by approximating the propagation direction of the test signal to the first direction for the component velocity calculation, the complexity of the calculation is greatly simplified, and the amount of calculation and the error that may be introduced are reduced under the premise of ensuring a certain accuracy, so that the system can process the reflected signal data more efficiently.

[0129] 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, combinations 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, but also includes more effective 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 calibration system, characterized in that: Includes speed radar, turntable and processor; The turntable is used to rotate at a stable speed; The speed measuring radar is used to transmit test signals to different positions of the side of the rotating turntable in a two-dimensional scanning manner, and collect the test signals reflected by different positions of the side of the turntable in real time; and is also used to perform data processing on the reflected test signals to determine the test data cloud diagrams of different positions of the side of the turntable; The processor is used to calculate the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal based on the diameter of the turntable and the stable rotation speed; and is also used to calibrate the actual conversion coefficient between the test data and the speed on the test data cloud chart based on the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal.

2. The radar speed measurement calibration system according to claim 1, characterized in that: It also includes a rotation speed measurement module, which is used to measure the stable rotation speed of the turntable.

3. The radar speed measurement calibration system according to claim 1, characterized in that: The processor is also used to modify the original conversion coefficient between the test data and the speed using the calibrated actual conversion system.

4. A radar speed measurement calibration method, characterized in that: Applied to the radar speed measurement calibration system as claimed in any one of claims 1 to 3, the calibration method comprises: A speed measuring radar is used to transmit test signals to different positions on the side of a rotating turntable in a two-dimensional scanning manner, and the test signals reflected by different positions on the side of the turntable are collected in real time; the turntable rotates at a stable speed; Performing data processing on the reflected test signal to determine the test data cloud diagrams at different positions on the side of the turntable; Calculating the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter of the turntable and the stable rotation speed; According to the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal, the actual conversion coefficient between the test data and the speed on the test data cloud diagram is calibrated.

5. The radar speed measurement calibration method according to claim 4, before calculating the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter of the turntable and the stable rotation speed, further comprising: The stable rotation speed of the rotating disk is measured.

6. The radar speed measurement calibration method according to claim 4, characterized in that: Performing data processing on the reflected test signal to determine the test data cloud diagrams at different positions on the side of the turntable includes: Determine the coordinates of different positions on the side of the turntable that reflect the test signal according to the propagation direction of the test signal emitted by the speed measuring radar during the scanning process in space and the relative position to the turntable; The coordinates of different positions on the side of the turntable that reflect the test signal are used to draw a cloud diagram of test data at different positions on the side of the turntable.

7. The radar speed measurement calibration method according to claim 4, characterized in that: Performing data processing on the reflected test signal to determine the test data cloud diagrams at different positions on the side of the turntable includes: Performing interference beat frequency on the reflected test signal and the local oscillator signal corresponding to the test signal to obtain a beat frequency signal; Calculating the difference frequency data of the test signal reflected at different positions on the side of the turntable according to the beat frequency signal; Different positions on the side of the turntable and the corresponding difference frequency data are used to draw a difference frequency data cloud diagram at different positions on the side of the turntable.

8. The radar speed measurement calibration method according to claim 4, characterized in that: Calculating the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter of the turntable and the stable rotation speed, including: Calculating the tangential velocity at any position on the side of the turntable according to the diameter of the turntable and the stable rotation speed; Based on the tangential velocity at any position on the side of the turntable and the propagation direction of the test signal corresponding to different positions on the side of the turntable that reflect the test signal, the component velocity of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal is calculated.

9. The radar speed measurement calibration method according to claim 4, characterized in that: Calculating the component velocities of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal according to the diameter of the turntable and the stable rotation speed, including: Calculating the tangential velocity at any position on the side of the turntable according to the diameter of the turntable and the stable rotation speed; The propagation direction of the test signal is approximated as a first direction, and the component velocities of different positions on the side of the turntable that reflects the test signal in the propagation direction of the test signal are calculated based on the tangential velocity at any position on the side of the turntable; wherein the first direction is the propagation direction of the test signal passing through the center of the turntable.

10. The radar speed measurement calibration method according to claim 4, characterized in that: After calibrating the actual conversion coefficient between the test data and the speed on the test data cloud diagram according to the component speeds of different positions on the side of the turntable reflecting the test signal in the propagation direction of the test signal, the method further includes: The calibrated actual conversion system is used to correct the original conversion coefficient between the test data and the speed.

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