A millimeter wave three-dimensional detection imaging radar

Abstract

The application provides a kind of millimeter wave three-dimensional detection imaging radar, including millimeter wave MIMO transceiving antenna, millimeter wave transceiving link, radar control processing module, external display control unit and power module;The antenna port area of mouth-shaped transceiving antenna array can be minimum under the condition that resolution requirement is relatively high, the antenna array carries out cutting angle processing, increases the transmitting and receiving spacing, reduces transmitting and receiving coupling, improves the action distance;wk imaging algorithm solves the problem that traditional three-dimensional FFT conversion imaging algorithm exists distance bending under large bandwidth, cannot realize focusing imaging and obtains material surface three-dimensional data.This application adopts millimeter wave technology, meets the surface of cement, ore and other material level in harsh environment to carry out three-dimensional imaging, detects silo inner wall sticky material, material virtual hitch, cavity;The application can also be applied to composite material flaw detection field, reconstructs three-dimensional image under surface layer by penetrating surface layer structure, realizes non-destructive flaw detection to composite material.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and specifically to a millimeter-wave three-dimensional detection and imaging radar. Background Technology

[0002] Active radar imaging uses electromagnetic waves emitted towards the target and the reflected echoes from the target to retrieve target information. It can operate in all weather and all time, meet the requirements of three-dimensional imaging in harsh environments, and has a certain penetrating power for composite materials and woven fabrics. It also has the capability of three-dimensional imaging below the surface and can be used in the field of composite material flaw detection.

[0003] Material silos are crucial facilities for storing materials, enabling transitional storage and providing a reasonable and stable supply to material handling equipment. To achieve automated control of material production and management, it is necessary to monitor silo levels, using real-time storage conditions as a basis for equipment production processes. This prevents equipment from operating under idle loads, ensures the rational scheduling and use of silo storage, and controls enterprise production costs.

[0004] The main methods for measuring the material level in silos include ultrasonic detection, laser detection, optical measurement, and radar detection. Among them: (1) Laser measurement and optical measurement are easily affected by dust and water vapor in the silo, resulting in significant interference and errors; (2) Traditional radar detection is usually a one-dimensional distance detection, which can only display the material level depth and cannot truly reflect the three-dimensional shape of the material surface in the silo.

[0005] Therefore, a testing system that can accurately reflect the three-dimensional morphology of the material surface in the silo is needed. Summary of the Invention

[0006] This invention addresses the problem of three-dimensional topography testing in silos by providing a millimeter-wave three-dimensional imaging radar. Employing millimeter-wave multiple-transmit, multiple-receive (MIMO) three-dimensional imaging technology, it enables three-dimensional imaging of the surface of cement, ore, and other materials in harsh environments with high dust, humidity, and water mist. This detects material adhesion, material misalignment, and voids on the inner walls of silos, preventing sudden material collapse and ensuring the safety of stored materials. Furthermore, due to the penetrating properties of millimeter waves, this invention can also be applied to composite material flaw detection. By penetrating the surface structure, it reconstructs a three-dimensional image of the underlying layer, achieving non-destructive flaw detection of composite materials.

[0007] This invention provides a millimeter-wave three-dimensional detection and imaging radar, comprising a millimeter-wave MIMO transceiver antenna, a millimeter-wave transceiver link, a radar control and processing module, an external display control unit, and a power module connected in sequence to the millimeter-wave MIMO transceiver antenna, the millimeter-wave transceiver link, and the radar control and processing module;

[0008] The millimeter-wave transceiver link receives the transmit control signal output from the radar control and processing module, generates a linear frequency modulated signal, amplifies the power, and outputs it to the millimeter-wave MIMO transceiver antenna. The millimeter-wave MIMO transceiver antenna transmits millimeter-wave signals to the material pile to be detected and receives the echo signals returned from the material pile. The millimeter-wave transceiver link receives the echo signals output from the millimeter-wave MIMO transceiver antenna, down-converts them to intermediate frequency signals, and outputs them to the radar control and processing module. The radar control and processing module performs radar signal control, intermediate frequency signal acquisition, data validity verification, three-dimensional imaging and fitting of the material surface, spatial volume calculation, and outputs the three-dimensional image of the material surface of the material pile to be detected to an external display and control unit in real time for display and monitoring. The power supply module supplies power to the millimeter-wave MIMO transceiver antenna, the millimeter-wave transceiver link, and the radar control and processing module.

[0009] The MIMO transceiver antenna is a U-shaped transceiver antenna array.

[0010] The millimeter-wave three-dimensional detection and imaging radar of the present invention, as a preferred embodiment, also includes a metal sealing structure;

[0011] The millimeter-wave MIMO transceiver antenna uses a dielectric waveguide. The millimeter-wave MIMO transceiver antenna, millimeter-wave transceiver link, radar control and processing module, and power module are all integrated into a single PCB board and encapsulated in a metal-sealed structure. The millimeter-wave MIMO transceiver antenna is a flat panel antenna facing the material pile to be detected. The material on the side of the metal-sealed structure facing the material pile to be detected is a millimeter-wave transparent material.

[0012] The millimeter-wave MIMO transceiver antenna includes a transmitting antenna array and a receiving antenna array. Both the transmitting and receiving antenna arrays are located at the edge and are perpendicular to each other. Both the transmitting and receiving antenna arrays are arranged in two columns and are spaced apart in a square shape.

[0013] The millimeter-wave MIMO transceiver antenna forms an equivalent sampling position through equivalent aperture processing, and the shape of the equivalent sampling position is hexagonal; the four corners of the millimeter-wave MIMO transceiver antenna are the transmit and receive isolation positions.

[0014] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the millimeter-wave MIMO transceiver antenna obtains the equivalent phase center of the antenna at the middle position through equivalent aperture processing.

[0015] The azimuth angular resolution of the three-dimensional material level is:

[0016] ;

[0017] The pitch angle resolution of the three-dimensional material level is:

[0018] ;

[0019] Wherein, the equivalent array size is The operating signal frequency;

[0020] ;

[0021] in, , For the transmitting antenna array channel coordinates and coordinate, , For the receiving antenna array channel coordinates and Coordinates; the entire antenna aperture is ;

[0022] The antenna aperture of a millimeter-wave MIMO transceiver antenna is minimized when the following conditions are met:

[0023] .

[0024] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the transmitting antenna array and the receiving antenna array are chamfered, and the element spacing between the transmitting antenna array and the receiving antenna array is:

[0025] or ;

[0026] This represents the coordinate spacing;

[0027] ,in, This is the operating signal frequency.

[0028] The millimeter-wave three-dimensional detection and imaging radar described in this invention, as a preferred embodiment, uses a linear frequency modulated continuous wave signal for its millimeter-wave MIMO transceiver antenna, achieving high range resolution. for:

[0029] ;

[0030] in, At the speed of light, For signal bandwidth;

[0031] radar signal bandwidth Angular resolution ≤ 1.6°, scanning angle range ≥ 120°.

[0032] The millimeter-wave three-dimensional detection and imaging radar of the present invention, in a preferred embodiment, includes a millimeter-wave transceiver link comprising a frequency source generation module and a receiving down-conversion module that are both connected to the radar control and processing module and the millimeter-wave MIMO transceiver antenna.

[0033] The frequency source generation module receives the output signal from the radar control and processing module, generates data, and generates a linear frequency modulated signal. After being driven and amplified, the signal is transmitted to the transmitting antenna array of the millimeter-wave MIMO transceiver antenna and radiated onto the surface of the material pile to be detected. The receiving downconversion module receives the echo signal output from the receiving antenna array of the millimeter-wave MIMO transceiver antenna, amplifies it with low noise, and downconverts it with the transmitted local oscillator signal to an intermediate frequency signal, which is then output to the radar control and processing module for ADC sampling processing.

[0034] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the radar control and processing module generates radar control signals to control the frequency band, bandwidth, output power, and duty cycle of the transmitted signals, and monitors the status of the radar system.

[0035] The radar control and processing module performs data validity verification by discarding data where the distance between the transmitting and receiving antennas in the transmitting and receiving antenna arrays is ≤8*wavelength to obtain the equivalent sampling position.

[0036] The radar control and processing module includes a radar control module connected to the millimeter-wave transceiver link, a signal acquisition module, and a processing module connected to the millimeter-wave MIMO transceiver antenna.

[0037] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the radar control and processing module uses the WK three-dimensional imaging algorithm to obtain three-dimensional data of the material surface to be detected.

[0038] The pile to be detected is discretized into a series of point sets. ,in and The spacing is the positional resolution. The spacing is the range resolution, obtained by solving the points. At different elevations echo signal amplitude ,by Location of the maximum value As The corresponding three-dimensional surface coordinates of the material pile to be detected ;

[0039] The method for the radar control processing module to perform surface fitting on the material surface is as follows: Perform 2D uniform interpolation fitting. Spatial coordinate points The height corresponding to the location The directional interpolation distances are respectively further reduce Planar distance yields refined 3D surface coordinate information.

[0040] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the radar control and processing module calculates the spatial volume as follows: the spatial volume V is:

[0041] .

[0042] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the radar control and processing module calculates a three-dimensional image of the material surface in the silo in real time and transmits the result to an external display and control unit in real time via a network interface.

[0043] In a preferred embodiment of the millimeter-wave three-dimensional detection and imaging radar described in this invention, the external display control unit includes a display terminal and an information control console.

[0044] The external display control unit is fixed outside the silo or inside the monitoring center and is connected to the radar control and processing module through a network communication interface. The external display control unit is used to centrally monitor the three-dimensional material level in each silo in real time. The monitoring center monitors the changes in the three-dimensional material level data and storage data of the silo in real time by issuing detection commands and receiving the returned three-dimensional material level surface information.

[0045] The millimeter-wave three-dimensional detection imaging radar of the present invention, as a preferred embodiment, includes the following steps in its imaging method:

[0046] S1. The external display control unit sends a three-dimensional imaging command to the radar control and processing module.

[0047] S2. The radar control and processing module receives commands and outputs transmission control signals to the millimeter-wave transceiver link.

[0048] S3, the millimeter-wave transceiver link generates a transmit signal and outputs it to the transmit antenna array of the millimeter-wave MIMO transceiver antenna;

[0049] S4. The transmitting antenna array transmits millimeter-wave signals to the material pile to be detected;

[0050] S5. The receiving antenna array of the millimeter-wave MIMO transceiver antenna receives the echo signal and outputs it to the millimeter-wave transceiver link. The millimeter-wave transceiver link performs down-conversion and outputs the intermediate frequency signal.

[0051] S6, the radar control and processing module performs intermediate frequency signal acquisition, processing, and three-dimensional imaging;

[0052] S7, the radar control and processing module uploads the three-dimensional imaging data to the external display and control unit, thus completing the imaging method of the millimeter-wave three-dimensional level detection imaging radar.

[0053] The present invention has the following advantages:

[0054] (1) The present invention uses a U-shaped transceiver antenna array, which minimizes the antenna aperture area when the resolution requirement is relatively high; the transceiver antenna array is chamfered to increase the distance between the transmitter and receiver, reduce the coupling between the transmitter and receiver, and improve the effective range.

[0055] (2) The present invention uses the wk imaging algorithm to solve the problem that the traditional three-dimensional FFT transformation imaging algorithm under large bandwidth has distance curvature and cannot achieve focused imaging to obtain three-dimensional data of the material surface.

[0056] (3) This invention employs millimeter-wave multiple-transmitter-multiple-receiver (MIMO) three-dimensional imaging technology to enable three-dimensional imaging of the surface of cement, ore, and other materials in harsh environments with high dust, high humidity, and abundant water mist. This allows for the detection of material adhesion, material misalignment, and voids on the inner wall of silos, preventing sudden material collapse and ensuring the safety of stored materials. Furthermore, due to the penetrating characteristics of millimeter waves, this invention can also be applied to the field of composite material flaw detection. By penetrating the surface structure, a three-dimensional image beneath the surface can be reconstructed, achieving non-destructive flaw detection of composite materials. Attached Figure Description

[0057] Figure 1 A block diagram of a millimeter-wave three-dimensional detection and imaging radar;

[0058] Figure 2 A flowchart of a millimeter-wave three-dimensional detection and imaging radar;

[0059] Figure 3 This is an internal schematic diagram of a millimeter-wave three-dimensional detection and imaging radar.

[0060] Figure 4 This is a schematic diagram of a millimeter-wave MIMO transceiver antenna for a millimeter-wave three-dimensional detection and imaging radar.

[0061] Figure 5 This is a schematic diagram of the scanning range of a millimeter-wave MIMO transceiver antenna for a millimeter-wave three-dimensional detection and imaging radar.

[0062] Figure 6 This is a schematic diagram of the operation of a millimeter-wave three-dimensional material level detection radar, which is a type of millimeter-wave three-dimensional detection and imaging radar.

[0063] Figure label:

[0064] 1. Millimeter-wave MIMO transceiver antenna; 11. Transmit antenna array; 12. Receive antenna array; 2. Millimeter-wave transceiver link; 21. Frequency source generation module; 22. Receiver down-conversion module; 3. Radar control and processing module; 31. Radar control module; 32. Signal acquisition module; 33. Processing module; 4. External display control unit; 5. Power supply module; 6. Metal-sealed structure. Detailed Implementation

[0065] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0066] like Figures 1-6 As shown, a millimeter-wave three-dimensional detection and imaging radar is used as an example, with an azimuth and elevation resolution of 1.6° and a range resolution of 0.1m.

[0067] like Figure 1 The diagram shown is a block diagram of a millimeter-wave three-dimensional material level detection radar, which mainly consists of five parts: millimeter-wave MIMO transceiver antenna 1, millimeter-wave transceiver link 2, radar control and processing module 3, external display control unit 4, and power supply module 5.

[0068] like Figure 2 The diagram shows the workflow of a millimeter-wave three-dimensional level detection radar.

[0069] like Figure 3 The diagram shows the internal installation of a millimeter-wave three-dimensional level detection radar. The millimeter-wave MIMO transceiver antenna 1, millimeter-wave transceiver link 2, radar control and processing module 3, and power module 5 are all housed within a high-strength, sealed metal casing 6 to withstand high humidity and dusty working environments. To improve radar integration, the power module, millimeter-wave MIMO transceiver antenna 1, transceiver link 2, and radar control and processing module 3 are designed on the same PCB board.

[0070] like Figure 4 The diagram shows a millimeter-wave MIMO transceiver antenna. The transmitting antenna 11 and the receiving antenna 12 are distributed at the edge and are vertically distributed. By processing the equivalent aperture, the equivalent phase center of the antenna at the middle position can be obtained.

[0071] like Figure 5 The diagram shows the scanning range of a millimeter-wave MIMO transceiver antenna, indicating that the scanning range of this MIMO transceiver antenna is 120 degrees.

[0072] Figure 6This is a schematic diagram of the operation of a millimeter-wave three-dimensional material level detection radar. It acquires three-dimensional data of the material silo surface through beam scanning and displays it in the external display control unit 4.

[0073] The functions of each module will be described in detail below.

[0074] Millimeter-wave MIMO transceiver antenna 1: The transceiver antenna 1 is designed as the core part of this invention. This invention adopts the following... Figure 4 The millimeter-wave MIMO flat panel antenna design shown includes the design of the following parts.

[0075] (1) Radar signal form: The present invention uses linear frequency modulated continuous wave signal.

[0076] (2) Range resolution: The range resolution of the system is determined by the bandwidth of the transmitted signal.

[0077] ;

[0078] in, For range resolution, At the speed of light, Assuming a ranging accuracy of 0.1m, the radar signal bandwidth should be calculated as follows: .

[0079] (3) Azimuth and Pitch Angular Resolution: The azimuth and pitch resolutions designed in this invention are angular resolutions, and the angular resolution should be ≤1.6°, that is, the position resolution at a position of 50m is... The position resolution at a location of 10m is ;

[0080] (4) MIMO antenna design

[0081] Assumption A set of equivalent units. The location of the equivalent unit. Number the equivalent unit. This represents the number of equivalent cells. The equivalent array size is... This mainly depends on the azimuth and pitch angle resolutions of the three-dimensional material level, respectively:

[0082] ,in This is the operating signal frequency.

[0083] Given that the equivalent array size is satisfied, the positions of the MIMO transmit antenna elements and receive antenna elements should satisfy the following conditions:

[0084] ;

[0085] in , For the launch of the first channel and coordinate, , To receive the first channel and Coordinates, the entire antenna aperture is ,

[0086] Therefore, the antenna aperture is minimized when the following conditions are met:

[0087] ;

[0088] In practical applications, if the transmitting unit and the receiving unit cannot overlap, such as Figure 4 The U-shaped transceiver antenna array shown can achieve the smallest antenna aperture area when high resolution is required.

[0089] (5) MIMO antenna decoupling design

[0090] The three-dimensional level detection imaging radar operates in continuous wave mode, requiring simultaneous transmission and reception. However, if the transmitting and receiving channels are too close, the transmitted signal will directly enter the receiving channel, resulting in a strong direct wave that hinders the reception of weak signals over long distances. Therefore, this invention employs a chamfering process to increase the distance between the transmitter and receiver, reducing transmission and reception coupling and improving the effective range. The spacing between the units in the transmitter-receiver assembly is limited to meet the following conditions:

[0091] or ;

[0092] in , For the launch of the first channel and coordinate, , To receive the first channel and coordinate, The coordinate spacing is typically taken as... This ensures both the isolation between the transceiver arrays and the continuity and maximum size of the equivalent array, thus guaranteeing angular resolution.

[0093] According to the above design scheme, the transceiver antenna designed in this embodiment is as follows: Figure 4The array shown is shaped like a square, with transmitting antenna arrays 11 at the top and bottom, and receiving antenna arrays 12 on the left and right (the positions of the transmitting and receiving antennas can be changed). The array size is 64×64, the antenna element spacing is 6.25mm, the scanning angle range is ≥120°, and the center is the equivalent antenna position. To ensure isolation between transmitting and receiving antennas 11 and 12, the four corners of the U-shaped array are designed as transmitting and receiving isolation positions, and the spacing between the transmitting and receiving antennas is greater than 80mm. The antennas are in the form of dielectric waveguides and are integrated with the printed circuit board.

[0094] Transceiver Link 2: This link performs functions such as generating linear frequency modulated signals, power amplification, and receiving down-conversion. It mainly includes a frequency source generation module 21 and a receiving down-conversion module 22, etc. Figure 6 This is a schematic diagram of the transmit / receive link. The frequency source generation module 21 generates data by receiving signals from the radar control and processing module 3, producing a linear frequency modulated (LFM) signal. This LFM signal is amplified and transmitted to the transmitting antenna 11, radiating onto the surface of the material level in the silo. Simultaneously, the receiving antenna 12 receives the echo signal reflected from the surface of the material level in the silo. This echo signal is then amplified with low noise by the receiving down-conversion module 22 and down-converted to an intermediate frequency (IF) signal with the transmitted local oscillator signal. The IF signal is then output to the radar control and processing module 3 for ADC sampling processing.

[0095] Radar control processing module 3: Radar control processing module 3 adopts a miniaturized and integrated design. The entire processor is integrated into a single board, consisting of radar control module 31, signal acquisition module 32 and processing module 33, which performs three-dimensional imaging of the material level surface of the silo. It mainly realizes the following functions: (1) Radar signal control: generates radar control signals, controls the frequency band, bandwidth, output power and duty cycle of the transmitted signal and other signal characteristics, and monitors the status of the radar system;

[0096] (2) Intermediate frequency signal acquisition: Receive the intermediate frequency signal after downconversion from the transceiver link 2, perform analog-to-digital conversion (ADC) to obtain a digital signal;

[0097] (3) Three-dimensional imaging of the material surface: The WK imaging algorithm is adopted to solve the problem that the traditional three-dimensional FFT transformation imaging algorithm under large bandwidth has distance curvature and cannot achieve focused imaging to obtain three-dimensional data of the material surface. The material silo to be tested is discretized into a series of point sets. ,in and The spacing is the positional resolution. The spacing is the range resolution, obtained by solving the points. At different elevations echo signal amplitude ,by Location of the maximum value As Corresponding three-dimensional surface coordinate position .

[0098] (4) Material surface fitting: By using a 2D uniform interpolation fitting method The directional interpolation distances are respectively Further reduce Planar distances provide more detailed 3D surface coordinate information, remove interference from anomalies on the 3D surface, and further improve surface accuracy.

[0099] (5) Calculation of spatial volume: The formula for calculating spatial volume is:

[0100] ;

[0101] in, The new ones after uniform interpolation directional distance interval, Spatial coordinate points The altitude corresponding to the location.

[0102] (6) Calculate the three-dimensional image of the material surface in the silo in real time and transmit the results to the display terminal 4 and the information control console in real time through the network interface;

[0103] External display control unit 4: The external display control unit 4 is installed outside the silo or inside the monitoring center. It is used for centralized real-time monitoring of the three-dimensional material level in each silo and is connected to the radar signal processor via a network communication interface. The monitoring center sends out detection commands and receives the returned three-dimensional material level information to monitor the changes in the three-dimensional material level data and storage data of the silo in real time.

[0104] Power module 5: Provides external power to the millimeter-wave MIMO transceiver antenna 1, RF transceiver link 2 and radar control and processing module 3 to drive them to work normally. The power supply type is DC.

[0105] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A millimeter-wave three-dimensional detection and imaging radar, characterized in that: It includes a millimeter-wave MIMO transceiver antenna (1), a millimeter-wave transceiver link (2), a radar control and processing module (3), an external display control unit (4) connected in sequence, a power supply module (5) connected to the millimeter-wave MIMO transceiver antenna (1), the millimeter-wave transceiver link (2), and the radar control and processing module (3), and a metal sealing structure (6). The millimeter-wave transceiver link (2) receives the transmission control signal output by the radar control and processing module (3) and generates a linear frequency modulation signal, then amplifies the power and outputs it to the millimeter-wave MIMO transceiver antenna (1). The millimeter-wave MIMO transceiver antenna (1) transmits millimeter-wave signals to the material pile to be detected and receives the echo signals returned by the material pile to be detected. The millimeter-wave transceiver link (2) receives the echo signals output by the millimeter-wave MIMO transceiver antenna (1) and performs down-conversion to an intermediate frequency signal, which is then output to the radar control and processing module (3). The radar control and processing module (3) performs radar signal control, intermediate frequency signal acquisition, data validity confirmation, three-dimensional imaging and fitting of the material surface, spatial volume calculation, and outputs the three-dimensional image of the material surface of the material pile to be detected to the external display control unit (4) for display and monitoring in real time. The power supply module (5) supplies power to the millimeter-wave MIMO transceiver antenna (1), the millimeter-wave transceiver link (2), and the radar control and processing module (3). The MIMO transceiver antenna (1) is a U-shaped transceiver antenna array; The millimeter-wave MIMO transceiver antenna (1) uses a dielectric waveguide. The millimeter-wave MIMO transceiver antenna (1), the millimeter-wave transceiver link (2), the radar control and processing module (3), and the power supply module (5) are all integrated into a PCB board and encapsulated in the metal sealing structure (6). The millimeter-wave MIMO transceiver antenna (1) is a flat panel antenna facing the material pile to be detected. The material on the side of the metal sealing structure (6) facing the material pile to be detected is a millimeter-wave transparent material. The millimeter-wave MIMO transceiver antenna (1) includes a transmitting antenna array (11) and a receiving antenna array (12). The transmitting antenna array (11) and the receiving antenna array (12) are both distributed at the edge and perpendicular to each other. The transmitting antenna array (11) and the receiving antenna array (12) are both arranged in two columns and spaced apart in a square shape. The millimeter-wave MIMO transceiver antenna (1) forms an equivalent sampling position through equivalent aperture processing, and the shape of the equivalent sampling position is hexagonal; the four corners of the millimeter-wave MIMO transceiver antenna (1) are the transceiver isolation positions; The radar control and processing module (3) uses the ωk three-dimensional imaging algorithm to obtain the three-dimensional data of the material surface to be detected: The pile to be detected is discretized into a series of point sets. ,in and The spacing is the positional resolution. The spacing is the range resolution, obtained by solving the points. At different elevations echo signal amplitude ,by Location of the maximum value As The corresponding three-dimensional surface coordinates of the material pile to be detected ; The method for the radar control processing module (3) to fit the material surface is as follows: Perform 2D uniform interpolation fitting. Spatial coordinate points The height corresponding to the location The directional interpolation distances are respectively further reduce Planar distance yields refined 3D surface coordinate information; The method for calculating the spatial volume by the radar control processing module (3) is as follows: The spatial volume V is: ； The radar control processing module (3) calculates the three-dimensional image of the material surface in the silo in real time and transmits the result to the external display control unit (4) in real time through the network interface.

2. The millimeter-wave three-dimensional detection and imaging radar according to claim 1, characterized in that: The millimeter-wave MIMO transceiver antenna (1) obtains the equivalent phase center of the antenna at the middle position through equivalent aperture processing; The azimuth angular resolution of the three-dimensional material level is: ； The pitch angle resolution of the three-dimensional material level is: ； Wherein, the equivalent array size is The operating signal frequency; ； in, , For the transmitting antenna array (11) channel coordinates and coordinate, , For the receiving antenna array (12) channel coordinates and coordinate; The entire antenna aperture is ; A set of equivalent units. The location of the equivalent unit; The aperture of the millimeter-wave MIMO transceiver antenna (1) is minimized when the following conditions are met: 。 3. The millimeter-wave three-dimensional detection and imaging radar according to claim 2, characterized in that: The transmitting antenna array (11) and the receiving antenna array (12) are chamfered, and the unit spacing between the transmitting antenna array (11) and the receiving antenna array (12) is: ； or ; This represents the coordinate spacing; ,in, This is the operating signal frequency.

4. The millimeter-wave three-dimensional detection and imaging radar according to claim 1, characterized in that: The millimeter-wave MIMO transceiver antenna (1) uses a linear frequency modulated continuous wave signal, with a range resolution of [missing information]. for: ； in, At the speed of light, For signal bandwidth; radar signal bandwidth Angular resolution ≤ 1.6°, scanning angle range ≥ 120°.

5. A millimeter-wave three-dimensional detection and imaging radar according to claim 1, characterized in that: The millimeter-wave transceiver link (2) includes a frequency source generation module (21) and a receiving down-conversion module (22) that are connected to the radar control and processing module (3) and the millimeter-wave MIMO transceiver antenna (1). The frequency source generation module (21) receives the output signal from the radar control and processing module (3), generates data, generates a linear frequency modulated signal, and then transmits it to the transmitting antenna array (11) of the millimeter-wave MIMO transceiver antenna (1) after driving amplification, and radiates it to the surface of the material pile to be detected; the receiving downconversion module (22) receives the echo signal output from the receiving antenna array (12) of the millimeter-wave MIMO transceiver antenna (1), performs low-noise amplification, and downconverts it with the transmitted local oscillator signal to an intermediate frequency signal, which is then output to the radar control and processing module (3) for ADC sampling processing.

6. A millimeter-wave three-dimensional detection and imaging radar according to claim 1, characterized in that: The radar control processing module (3) generates radar control signals to control the frequency band, bandwidth, output power and duty cycle of the transmitted signals, and monitors the status of the radar system. The radar control processing module (3) performs data validity verification by discarding data in the transmitting antenna array (11) and the receiving antenna array (12) where the distance between the transmitting antenna and the receiving antenna is ≤8*wavelength to obtain the equivalent sampling position; The radar control and processing module (3) includes a radar control module (31), a signal acquisition module (32), and a processing module (33) connected to the millimeter-wave transceiver link (2).

7. A millimeter-wave three-dimensional detection and imaging radar according to claim 1, characterized in that: The external display control unit (4) includes a display terminal and an information control console; The external display control unit (4) is fixed outside the silo or inside the monitoring center and connected to the radar control processing module (3) through a network communication interface. The external display control unit (4) is used to centrally monitor the three-dimensional material level in each silo in real time. The monitoring center monitors the changes in the three-dimensional material level data and storage data of the silo in real time by issuing detection commands and receiving the returned three-dimensional material level information.

8. A millimeter-wave three-dimensional detection and imaging radar according to any one of claims 1 to 7, characterized in that: The imaging method of the millimeter-wave three-dimensional detection imaging radar includes the following steps: S1. The external display control unit (4) sends a three-dimensional imaging command to the radar control processing module (3); S2, The radar control processing module (3) receives the instruction and outputs the transmission control signal to the millimeter wave transceiver link (2); S3. The millimeter-wave transceiver link (2) generates a transmission signal and outputs it to the transmission antenna array (11) of the millimeter-wave MIMO transceiver antenna (1). S4. The transmitting antenna array (11) transmits millimeter-wave signals to the material pile to be detected; S5. The receiving antenna array (12) of the millimeter-wave MIMO transceiver antenna (1) receives the echo signal and outputs it to the millimeter-wave transceiver link (2). The millimeter-wave transceiver link (2) performs down-conversion and outputs the intermediate frequency signal. S6. The radar control and processing module (3) performs intermediate frequency signal acquisition, processing and three-dimensional imaging; S7. The radar control and processing module (3) uploads the three-dimensional imaging data to the external display control unit (4), and the imaging method of the millimeter-wave three-dimensional material level detection imaging radar is completed.

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