Distance determination method and device for target object, radar liquid level meter, intelligent container

Abstract

The application discloses a distance determination method and device of a target object, a radar liquid level meter and an intelligent container, and comprises the following steps: acquiring initial planar array data collected by a millimeter wave radar; performing time-frequency conversion on the initial planar array data in the distance dimension to obtain first target planar array data, wherein the first target planar array data is the spectrum information of all planar array channels corresponding to the initial planar array data; determining a distance set corresponding to the first target planar array data according to the spectrum information; and determining the distance between the millimeter wave radar and the target object according to the angle between the antenna surface of the millimeter wave radar and the plane where the target object is located and the distance value in the distance set, so as to realize the technical effects of miniaturization of a radar measurement device and convenient and accurate measurement process.

Description

Technical Field

[0001] This application relates to the field of radar ranging, and more specifically, to a method and apparatus for determining the distance to a target object, a radar level gauge, and a smart container. Background Technology

[0002] Most existing millimeter-wave radar level gauges use horn antennas, which are large and space-consuming. On the other hand, existing flow velocity and level measurements are performed using separate radar modules, which require higher costs and larger sizes, resulting in larger radar measurement equipment and more complex measurement processes. Summary of the Invention

[0003] This application provides a method and apparatus for determining the distance to a target object, a radar level gauge, and a smart container, to at least solve the technical problems of large-scale radar measurement equipment and complex measurement processes.

[0004] According to one aspect of the embodiments of this application, a method for determining the distance to a target object is provided, comprising: acquiring initial array data collected by a millimeter-wave radar; performing time-frequency conversion on the initial array data in the distance dimension to obtain first target array data, wherein the first target array data is the spectrum information of all array channels corresponding to the initial array data; determining a distance set corresponding to the first target array data based on the spectrum information; and determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set.

[0005] Optionally, matrix data corresponding to multiple second target array channels can be selected from the first target array data corresponding to all array channels of the millimeter-wave radar, wherein the matrix data corresponding to the multiple second target array channels are arranged in a regular shape in the first target array.

[0006] Optionally, determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set, includes: determining a preset amplitude threshold; using the preset amplitude threshold to detect the spectrum corresponding to the spectrum information, and selecting effective distances from the distance set based on the detection results to obtain an effective distance set; and determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the effective distances in the effective distance set.

[0007] Optionally, determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the effective distances in the effective range set, includes: for each effective distance in the effective range set, performing Fourier transforms on the longitudinal and transverse directions of the first target array data to obtain an angle spectrum, wherein the transverse direction of the angle spectrum is the transverse angle, and the longitudinal direction of the angle spectrum is the longitudinal angle; selecting a target distance from the effective distances in the effective range set based on the angle spectrum, and determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the target distance.

[0008] Optionally, selecting a target distance from the effective distances in the effective distance set based on the angle spectrum includes: determining the effective distances in the angle spectrum where both the lateral angle and the longitudinal angle are preset values, and using the effective distances where both the lateral angle and the longitudinal angle are the preset values ​​as the target distance.

[0009] Optionally, the target object is a moving object located in the scanning area of ​​the millimeter-wave radar; the method further includes: performing a time-frequency transformation of the velocity dimension on the data corresponding to the spectral information to obtain velocity dimension spectral information; determining velocity information corresponding to the distance between the millimeter-wave radar and the target object based on the velocity dimension spectral information, wherein the velocity information includes the moving speed of the target object.

[0010] Optionally, before determining the effective distance corresponding to when both the lateral angle and the longitudinal angle in the angle spectrum are preset values ​​from the effective distance, the method further includes: performing phase compensation on the longitudinal angle based on the velocity information.

[0011] Optionally, determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the target distance, includes: statistically analyzing the target distances within a preset time period to obtain statistical results; performing median filtering on all target distances in the statistical results, and using the median-filtered distance value as the distance between the millimeter-wave radar and the target object.

[0012] Optionally, the preset amplitude threshold is determined based on the attenuation level of the millimeter-wave radar.

[0013] According to another aspect of the embodiments of this application, a target object distance determination device is also provided, comprising: an acquisition module for acquiring initial array data collected by a millimeter-wave radar; a conversion module for performing time-frequency conversion of the initial array data in the distance dimension to obtain first target array data, wherein the first target array data is the spectrum information of all array channels corresponding to the initial array data; a determination module for determining a distance set corresponding to the first target array data based on the spectrum information; and a calculation module for determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set.

[0014] According to another aspect of the embodiments of this application, a non-volatile storage medium is also provided, the non-volatile storage medium including a stored program, wherein, when the program is running, it controls the device where the non-volatile storage medium is located to execute the above-mentioned distance determination method for the target object.

[0015] According to another aspect of the embodiments of this application, a radar level gauge is also provided, including: a signal transceiver circuit for transmitting and receiving wireless signals; a memory for storing a program; and a processor for running the program stored in the memory, wherein the program executes the above-described target object distance determination method during runtime.

[0016] According to another aspect of the embodiments of this application, a smart container is also provided, including: a liquid container and a radar level gauge installed above the liquid surface stored in the liquid container; the radar level gauge is the radar level gauge described in the embodiments of this application.

[0017] According to another aspect of the embodiments of this application, an operating device is also provided, including: the smart container in the embodiments of this application.

[0018] In this embodiment, initial array data collected by millimeter-wave radar is acquired; time-frequency conversion of the initial array data in the range dimension is performed to obtain first target array data, wherein the first target array data is the spectrum information of all array channels corresponding to the initial array data; a range set corresponding to the first target array data is determined based on the spectrum information; and the distance between the millimeter-wave radar and the target object is determined based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the range set, so as to achieve the technical effect of miniaturization of radar measurement equipment and convenient and accurate measurement process. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a flowchart of a method for determining the distance to a target object according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of a radar antenna arrangement according to an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of radar antenna channel matrix data according to an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of a range spectrum detector according to an embodiment of this application;

[0024] Figure 5 This is a schematic diagram of the 2D FFT angular spectrum of a target object according to an embodiment of this application;

[0025] Figure 6 This is a schematic diagram of a millimeter-wave radar level gauge placed inside the pesticide tank of a plant protection aircraft, according to an embodiment of this application.

[0026] Figure 7 This is a schematic diagram of a distance determination device for a target object according to an embodiment of this application;

[0027] Figure 8 This is a schematic diagram of a target object distance determination device according to an embodiment of this application;

[0028] Figure 9 This is a schematic diagram of a radar level gauge device according to an embodiment of this application;

[0029] Among them, 1-millimeter-wave radar level gauge; 2-plant protection aircraft-mounted medicine box. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] Most millimeter-wave radar level gauges use horn antennas, which are bulky and space-consuming. Furthermore, existing flow velocity and level measurements are performed using separate radar modules, requiring higher costs and larger sizes. This application combines multiple applications of radar ranging and velocity measurement, utilizing spectrum conversion and sampling data to quickly determine the distance between the measurement point and the target object's plane. Simultaneously, it combines the angle between the antenna surface and the target object's plane to quickly and accurately determine the distance between the millimeter-wave radar and the target object. When the radar level gauge based on this measurement method is applied to different products, it can also achieve rapid and accurate measurement of the required distance for the product. In this application, in this embodiment, initial array data collected by millimeter-wave radar is acquired; the initial array data is converted to time-frequency data in the distance dimension to obtain first target array data, wherein the first target array data is the spectrum information of all array channels corresponding to the initial array data; a distance set corresponding to the first target array data is determined based on the spectrum information; the distance between the millimeter-wave radar and the target object is determined based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set. By performing time-frequency conversion on the acquired radar array data and combining it with the angle between the radar antenna surface and the target object, the distance between the radar measurement point and the target object is quickly determined, thereby achieving the technical effect of miniaturization of radar measurement equipment and convenient and accurate measurement process.

[0033] According to an embodiment of the present invention, a method embodiment for determining the distance of a target object is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0034] Under the above operating environment, Figure 1 This is a flowchart of a method for determining the distance to a target object according to an embodiment of this application, as shown below. Figure 1 As shown, the method includes the following steps:

[0035] Step S102: Obtain the initial array data acquired by the millimeter-wave radar;

[0036] It should be noted that the radar used in this embodiment is a millimeter-wave radar. In one optional embodiment, the millimeter-wave radar antenna can adopt a 4-transmit 12-receive scheme, that is, 4 transmitting antennas and 12 receiving antennas, including but not limited to using a RF scheme of UMS (Unified Messaging Service). The antenna placement in this embodiment can be as follows: Figure 2 The method shown is not limited to this one; any radar capable of implementing a 4D array can apply the method proposed in this application.

[0037] In some embodiments of this application, acquiring the initial array data collected by the millimeter-wave radar includes: acquiring the initial radar signal matrix data through each array channel of the millimeter-wave radar. It should be noted that, for ease of description, the millimeter-wave radar used in the embodiments of this application can adopt the fmcw (Frequency Modulated Continuous Wave) modulation mechanism. To better explain the process of acquiring array data, an example is given: 4 transmitting antennas emit 19 chirp (sawtooth wave modulation signals), where the sawtooth wave modulation signal is a sine wave signal whose frequency changes linearly with time in a sawtooth pattern. The system consists of 16 chirs for transmission channel TX1, and one chirp each for transmission channels TX2, TX3, and TX4. Each time transmission channel TX transmits, receiving channels RX1-RX12 simultaneously receive ADC sampling, resulting in a 16-chirp sequence of 1TX*12RX*16 chirps and a 1-chirp channel matrix of 4TX*12RX. In this embodiment, the radar antenna's transmitting surface is set at an acute angle to the horizontal plane, allowing the angle sensor to measure the radar's angle relative to the horizontal plane. During signal transmission, there is no need to use a waveguide medium to guide the antenna signal; instead, the antenna's transmitting surface is directly pointed towards the target object. This method is simple, convenient, and easy to operate. Simultaneously, by transmitting as many sawtooth wave modulated signals as possible, more matrix data is received, resulting in more comprehensive array data and more fundamental computational data.

[0038] S104, Perform time-frequency conversion of the distance dimension on the initial array data to obtain the first target array data, wherein the first target array data is the spectral information of all array channels corresponding to the initial array data;

[0039] It should be noted that the initial array data is subjected to time-frequency transformation in the distance dimension to obtain the first target array data. This time-frequency transformation can be processed using Fourier transform to obtain spectral information.

[0040] S106, determine the distance set corresponding to the first target array data based on the spectrum information;

[0041] In some embodiments of this application, to further reduce data computation and improve recognition efficiency, before determining the distance set corresponding to the target array data based on the spectrum information, multiple matrix data corresponding to second target array channels can be selected from the first target array data corresponding to all array channels of the millimeter-wave radar. The matrix data corresponding to the multiple second target array channels are arranged in a regular graphic shape within the first target array, such as... Figure 3 As shown, the 4*9 channels within the dashed box in the middle of the 4TX*12RX channel matrix data of one chirp are taken as a surface array, which is the selection of regular graphics. Of course, all channels can be taken to improve the horizontal resolution. FFT (fast Fourier transform) is performed on each channel of the 4*9 channel surface array to obtain the 4*9 channel distance dimension FFT result, thus obtaining the distance spectrum.

[0042] In some embodiments of this application, the effective distance is determined by determining a preset amplitude threshold; the spectrum corresponding to the spectrum information is detected using the preset amplitude threshold, and an effective distance is selected from the distance set based on the detection result to obtain an effective distance set.

[0043] It should be noted that the process of detecting the spectrum may include: determining the distances in the spectrum information that are higher than a preset amplitude threshold as effective distance values, such as... Figure 4 As shown in the figure, the horizontal line can be considered the straight line containing the preset amplitude threshold. Based on this, values ​​in the distance spectrum waveform above the horizontal line can be taken as valid distance values. The preset amplitude threshold can be determined based on the attenuation level of the millimeter-wave radar, for example, through the CFA algorithm. By filtering the valid distances, the signal strength is ensured, thereby ensuring the accuracy of the acquired distance and making the data more accurate.

[0044] It should be noted that the 1TX*12RX*16 chirps sequence data generated by the millimeter-wave radar transmitting sawtooth wave modulated signals is subjected to longitudinal and transverse FFT to obtain the distance and corresponding radial velocity of radiating targets above the radar field of view within the radar's field of view. Here, the Fast Fourier Transform is used, which greatly reduces the amount of computation required for the computer to perform the Fourier Transform. In particular, the more sampling points are transformed, the more significant the saving in computation of the Fast Fourier Transform algorithm becomes, which significantly reduces the computation time and improves the efficiency of data acquisition.

[0045] S108, determine the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance value in the distance set;

[0046] In some embodiments of this application, determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the effective distances in the effective distance set, includes: for each effective distance in the effective distance set, performing Fourier transforms on the longitudinal and transverse directions of the first target array data to obtain an angle spectrum, wherein the transverse direction of the angle spectrum is the horizontal angle and the longitudinal direction of the angle spectrum is the longitudinal angle; then selecting a target distance from the effective distances in the effective distance set based on the angle spectrum, and determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the target distance.

[0047] Specifically, the effective distances corresponding to when both the lateral and longitudinal angles in the angle spectrum are preset values ​​are determined from the effective distances, and these effective distances are used as the target distances. The accuracy of the extracted effective distances is further improved by using the effective distances corresponding to when both the lateral and longitudinal angles in the angle spectrum are preset values.

[0048] In some embodiments of this application, the target object is a moving object located in the scanning area of ​​the millimeter-wave radar; the method can also perform a time-frequency transformation of the velocity dimension on the data corresponding to the spectral information to obtain velocity dimension spectral information; based on the velocity dimension spectral information, determine the velocity information corresponding to the distance between the millimeter-wave radar and the target object, wherein the velocity information is the moving speed of the target object.

[0049] It should be noted that, through the above, when the preset values ​​of the horizontal and vertical angles of the center of the radar panel are 0 for a certain period of time, the measured distance range0 of the target directly below the center of the radar panel (the accuracy range can be set according to the requirements) can be obtained, and the velocity vel0 corresponding to the distance range0 can be obtained according to the above steps; when the preset value of the angle between the radar antenna surface and the horizontal line is not 0, but α, according to the geometric relationship, the height h of the liquid surface from the radar can be obtained as range0*cosα; the flow velocity v = vel0 / cos(π / 2-α).

[0050] It should be noted that by performing a Fast Fourier Transform on each effective distance value of the obtained distance spectrum result on the horizontal 9 channels and then on the vertical 4 channels, since there is a time interval between the signal transmissions of the four transmission channels, the calculation of the vertical angle uses a virtual channel composed of all four transmission channels, i.e., the vertical direction of the array.

[0051] In some embodiments of this application, if the target has velocity, changes in velocity will cause changes in the phase of the echo, which will introduce errors when calculating the longitudinal angle using the channel, leading to inaccurate measurement of the vertical angle. Therefore, before determining the effective distance corresponding to when both the lateral and longitudinal angles in the angle spectrum are preset values ​​from the effective distance, the method can perform phase compensation on the longitudinal angle based on the velocity information. The specific method of compensation includes: after obtaining the target distance and velocity of the target object, subtracting the phase difference introduced by the velocity when calculating the longitudinal angle to obtain the phase-compensated longitudinal angle. This allows for phase compensation of the longitudinal angle based on the velocity of the target object; the phase-compensated 2D FFT angle spectrum can be obtained as follows... Figure 5 As shown, the horizontal axis represents the horizontal angle, and the vertical axis represents the vertical angle. It should be noted that the horizontal angle is the same as the lateral angle mentioned above, and the vertical angle is the same as the longitudinal angle mentioned above. In the embodiment where the preset values ​​of the lateral and longitudinal angles are 0, only the target point corresponding to the distance value where both the lateral and longitudinal angles are 0 is considered to be the location of the target. This can be understood as the target to be detected being located directly below the center of the radar panel.

[0052] In some embodiments of this application, to further improve the target detection results of the millimeter-wave radar, the above-mentioned determination of the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the target distance, may further include: statistically analyzing the target distances within a preset time period to obtain statistical results; performing median filtering on all target distances in the statistical results, and using the median-filtered distance value as the distance between the millimeter-wave radar and the target object.

[0053] In some embodiments of this application, the present invention can be used to measure the liquid level of pesticide in the pesticide tank of an agricultural machinery, and also to measure the height of remaining particles in the feed tank. When used in the pesticide tank, it can also be used to measure speed and correct for the influence of fluctuations during aircraft flight on the liquid level.

[0054] Furthermore, since most existing plant protection drones use contact-type level gauges, such as Hall effect sensors or float level gauges, the liquids in the pesticide tanks of plant protection drones are often corrosive and viscous. This will cause the contact-type level gauges to be corroded or contaminated with pesticides, resulting in inaccurate measurements. On the other hand, most existing millimeter-wave radar level gauges use horn antennas, which are large and space-consuming, making them unusable in scenarios with smaller containers, such as the pesticide tanks of plant protection drones.

[0055] Therefore, based on the same inventive concept, this application also proposes a plant protection aircraft-borne pesticide tank with a built-in millimeter-wave radar level gauge 1. This level gauge is small in size, unaffected by pesticide adhesion or corrosion, and can obtain accurate measurement values ​​even when the plant protection aircraft is shaking. The radar level gauge 1 is located inside the plant protection aircraft-borne pesticide tank 2. Figure 6 As shown. Therefore, in the process of measuring liquid level using the millimeter-wave radar level gauge 1 through the aforementioned target object distance determination method, steps S102 to S108 can be executed cyclically within a preset time period to obtain the liquid surface distance directly below the radar within that preset time period and to obtain statistical results. Then, all target distances in the statistical results are subjected to median filtering, and the filtered distance value is used as the distance between the millimeter-wave radar and the liquid surface. The remaining liquid level in the medicine tank can then be calculated based on the height of the medicine tank and the filtered distance value. Thus, by filtering multiple distance values ​​within a preset time period, the influence of large-angle shaking of the operating equipment on the liquid level measurement value can be reduced. The operating equipment may include a plant protection machine or an unmanned vehicle.

[0056] In some embodiments of this application, a MIMO (multiple input multiple output) millimeter-wave radar with a microstrip antenna and frequency-modulated continuous wave (FMCW) modulation is used to achieve ranging, velocity, and angle measurement. The installation angle is automatically obtained through an angle sensor, and there are no requirements for the wave width, thus reducing the antenna area. For water flow velocity measurement scenarios, the liquid level height and flow velocity are obtained using geometric relationships. The installation angle of this liquid level and flow velocity radar is not strictly required, and the measurement of liquid level and flow velocity is achieved with the volume of a single module and a single board. For material height measurement scenarios in containers, it can realize low-cost, small-volume, corrosion-resistant, and non-stick non-contact measurement of the liquid level in the tank of an agricultural drone. Finally, median filtering is performed to eliminate the influence of large-angle aircraft swaying on liquid level fluctuations, ultimately obtaining a stable and reliable liquid level height value.

[0057] In some embodiments of this application, the distance determination method for the target object can also be applied to water flow velocity measurement scenarios in canals or rivers to detect water flow velocity or liquid level height, such as... Figure 7 As shown. In addition, in some embodiments, the measures described above for reducing the impact of fluctuations on the measurement results can also be used to reduce the impact of fluctuations caused by the flow of rivers or canals on the liquid level measurement results, thereby improving the accuracy of the liquid level measurement, which will not be elaborated here.

[0058] In some embodiments of this application, a distance determination device for a target object is also provided, such as... Figure 8 As shown, it includes: an acquisition module 10, used to acquire initial array data collected by millimeter-wave radar; a conversion module 12, used to perform time-frequency conversion of the initial array data in the range dimension to obtain first target array data, wherein the first target array data is the spectrum information of all array channels corresponding to the initial array data; a determination module 14, used to determine the distance set corresponding to the first target array data based on the spectrum information; and a calculation module 16, used to determine the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set.

[0059] The conversion module 12 includes a conversion submodule and a selection submodule. The conversion submodule is used to perform time-frequency conversion of the initial array data in the range dimension to obtain the first target array data. The selection submodule is used to select matrix data corresponding to multiple second target array channels from the first target array data corresponding to all array channels of the millimeter-wave radar. The matrix data corresponding to the multiple second target array channels are arranged in a regular shape in the first target array.

[0060] The calculation module 16 includes a first calculation submodule, a second calculation submodule, a third calculation submodule, a fourth calculation submodule, and a filtering submodule. The first calculation submodule is used to determine a preset amplitude threshold; to detect the spectrum corresponding to the spectrum information using the preset amplitude threshold, and to select effective distances from the distance set based on the detection results, thus obtaining an effective distance set; and to determine the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, as well as the effective distances in the effective distance set. The second calculation submodule is used to perform Fourier transforms on the longitudinal and transverse directions of the first target array data for each effective distance in the effective distance set, respectively, to obtain an angle spectrum, wherein the transverse direction of the angle spectrum represents the transverse angle, and the longitudinal direction of the angle spectrum represents the longitudinal angle; to select the target distance from the effective distances in the effective distance set based on the angle spectrum, and based on the millimeter-wave radar... The distance between the millimeter-wave radar and the target object is determined by the angle between the antenna surface and the plane where the target object is located, and the target distance. The third calculation submodule is used to determine the effective distance corresponding to the preset values ​​of the lateral angle and the longitudinal angle in the angle spectrum from the effective distance, and the effective distance corresponding to the preset values ​​of the lateral angle and the longitudinal angle is used as the target distance. The fourth calculation submodule is used to perform a time-frequency transformation of the velocity dimension on the data corresponding to the spectrum information to obtain the velocity dimension spectrum information. Based on the velocity dimension spectrum information, the velocity information corresponding to the distance between the millimeter-wave radar and the target object is determined, wherein the velocity information includes the moving speed of the target object. The filtering submodule is used to statistically analyze the target distance within a preset time period to obtain the statistical result. Median filtering is performed on all target distances in the statistical result, and the distance value obtained after median filtering is used as the distance between the millimeter-wave radar and the target object.

[0061] In some embodiments of this application, a radar level gauge 30 is also provided, such as... Figure 9 As shown, it includes: a signal transceiver circuit 301 for transmitting and receiving wireless signals; a memory 303 for storing programs; and a processor 302 for running the program stored in the memory 303, wherein the program executes a method for determining the distance of a target object during runtime.

[0062] In some embodiments of this application, a smart container is also provided, including: a liquid container and a radar level gauge installed above the liquid surface of the liquid stored in the liquid container; the radar level gauge is the radar level gauge described in the embodiments of this application. Based on the manufacturing principle of this smart container, it is possible to manufacture containers that can measure the liquid level height inside the container in real time, including but not limited to the plant protection airborne medicine box with a built-in millimeter-wave radar level gauge 1 proposed in this application.

[0063] In some embodiments of this application, an operating device is also provided, including: the smart container in the embodiments of this application.

[0064] Specifically, the operating equipment can be an aircraft equipped with a pesticide sprayer, a car, train, or airplane equipped with a water tank for real-time measurement of liquid level.

[0065] In some embodiments of this application, a non-volatile storage medium is also provided, which includes a stored program, wherein, when the program is running, it controls the device where the non-volatile storage medium is located to execute a distance determination method for a target object.

[0066] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0067] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0068] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0069] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0070] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0071] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0072] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for determining the distance to a target object, characterized in that, include: Acquire the initial array data collected by the millimeter-wave radar; The initial array data is converted to time-frequency data in the distance dimension to obtain the first target array data, which is the spectral information of all array channels corresponding to the initial array data. Based on the spectrum information, determine the distance set corresponding to the first target array data; The distance between the millimeter-wave radar and the target object is determined based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set. The target object is a moving object located within the scanning area of ​​the millimeter-wave radar. A time-frequency transformation in the velocity dimension is performed on the data corresponding to the spectral information to obtain velocity-dimensional spectral information. Based on the velocity-dimensional spectral information, velocity information corresponding to the distance between the millimeter-wave radar and the target object is determined. The velocity information includes the moving speed of the target object. The angle is determined by an angle sensor. In the case where the target object is liquid medicine in a medicine tank, the influence of fluctuations generated during aircraft flight on the liquid level is corrected based on the moving speed. The height of the liquid medicine in the medicine tank is determined based on the distance.

2. The method according to claim 1, characterized in that, Before determining the distance set corresponding to the target array data based on the spectral information, the method further includes: From the first target array data corresponding to all array channels of the millimeter-wave radar, select matrix data corresponding to multiple second target array channels, wherein the matrix data corresponding to the multiple second target array channels are arranged in a regular shape in the first target array.

3. The method according to claim 1, characterized in that, Determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the range set, includes: Determine the preset amplitude threshold; The spectrum corresponding to the spectrum information is detected using the preset amplitude threshold, and an effective distance is selected from the distance set based on the detection result to obtain an effective distance set; The distance between the millimeter-wave radar and the target object is determined based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, as well as the effective distance in the effective distance set.

4. The method according to claim 3, characterized in that, Determining the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the effective distances in the effective range set, includes: For each effective distance in the effective distance set, Fourier transforms are performed on the longitudinal and transverse directions of the first target array data to obtain an angle spectrum, wherein the transverse direction of the angle spectrum is the transverse angle and the longitudinal direction of the angle spectrum is the longitudinal angle. The target distance is selected from the effective distances in the effective distance set based on the angle spectrum, and the distance between the millimeter-wave radar and the target object is determined based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, as well as the target distance.

5. The method according to claim 4, characterized in that, Selecting a target distance from the effective distance set based on the angle spectrum includes: The effective distances are determined from the effective distances when both the lateral and longitudinal angles in the angle spectrum are preset values, and the effective distances when both the lateral and longitudinal angles are the preset values ​​are taken as the target distances.

6. The method according to claim 4, characterized in that, Before determining the effective distance from the effective distance where both the lateral and longitudinal angles in the angle spectrum are preset values, the method further includes: Phase compensation is performed on the longitudinal angle based on the velocity information.

7. The method according to claim 4, characterized in that, The determination of the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the target distance, includes: The target distance within a preset time period is statistically analyzed to obtain the statistical results; Median filtering is applied to all target distances in the statistical results, and the filtered distance value is used as the distance between the millimeter-wave radar and the target object.

8. The method according to claim 3, characterized in that, The preset amplitude threshold is determined based on the attenuation level of the millimeter-wave radar.

9. A distance determination device for a target object, comprising: The acquisition module is used to acquire the initial array data collected by the millimeter-wave radar; The conversion module is used to perform time-frequency conversion of the initial array data in the distance dimension to obtain the first target array data, wherein the first target array data is the spectral information of all array channels corresponding to the initial array data; The determination module is used to determine the distance set corresponding to the first target array data based on the spectrum information; The calculation module is used to determine the distance between the millimeter-wave radar and the target object based on the angle between the antenna surface of the millimeter-wave radar and the plane where the target object is located, and the distance values ​​in the distance set. The target object is a moving object located within the scanning area of ​​the millimeter-wave radar. The module performs a time-frequency transformation on the data corresponding to the spectral information in the velocity dimension to obtain spectral information in the velocity dimension. Based on the spectral information in the velocity dimension, it determines velocity information corresponding to the distance between the millimeter-wave radar and the target object. The velocity information includes the moving speed of the target object. The angle is determined by an angle sensor. In the case where the target object is liquid medicine in a medicine tank, the module corrects for the influence of fluctuations generated during aircraft flight on the liquid level based on the moving speed, and determines the height of the liquid medicine in the medicine tank based on the distance.

10. A non-volatile storage medium comprising a stored program, wherein, During program execution, the device containing the non-volatile storage medium is controlled to execute the distance determination method for the target object as described in any one of claims 1 to 8.

11. A radar level gauge, characterized in that, include: Signal transceiver circuit, used to transmit and receive wireless signals; Memory, used to store programs; A processor for running a program stored in the memory, which, when running, executes the distance determination method for a target object as described in any one of claims 1 to 8.

12. A smart container, characterized in that, include: A liquid container and a radar level gauge installed above the surface of the liquid stored in the liquid container; the radar level gauge is the radar level gauge as described in claim 11.

13. A working device, characterized in that, include: The smart container as described in claim 12.

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