WO2020134335A1 - 用于主动式微波毫米波安检设备的电磁成像装置 - Google Patents

用于主动式微波毫米波安检设备的电磁成像装置 Download PDF

Info

Publication number
WO2020134335A1
WO2020134335A1 PCT/CN2019/110381 CN2019110381W WO2020134335A1 WO 2020134335 A1 WO2020134335 A1 WO 2020134335A1 CN 2019110381 W CN2019110381 W CN 2019110381W WO 2020134335 A1 WO2020134335 A1 WO 2020134335A1
Authority
WO
WIPO (PCT)
Prior art keywords
antennas
transmission
array
sub
electromagnetic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2019/110381
Other languages
English (en)
French (fr)
Inventor
赵自然
游�燕
李元景
马旭明
武剑
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua University
Nuctech Co Ltd
Original Assignee
Tsinghua University
Nuctech Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsinghua University, Nuctech Co Ltd filed Critical Tsinghua University
Priority to US17/309,915 priority Critical patent/US12339352B2/en
Publication of WO2020134335A1 publication Critical patent/WO2020134335A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
    • G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
    • G01S13/9021—SAR image post-processing techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/03—Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/887—Radar or analogous systems specially adapted for specific applications for detection of concealed objects, e.g. contraband or weapons
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/04—Display arrangements
    • G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
    • G01S7/20—Stereoscopic displays; Three-dimensional [3D] displays; Pseudo-3D displays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/28—Details of pulse systems
    • G01S7/282—Transmitters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/12—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with electromagnetic waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V8/00—Prospecting or detecting by optical means
    • G01V8/005—Prospecting or detecting by optical means operating with millimetre waves, e.g. measuring the black losey radiation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S2013/0236—Special technical features
    • G01S2013/0245—Radar with phased array antenna

Definitions

  • the present disclosure relates to an electromagnetic imaging device, and more particularly to an electromagnetic imaging device for an active microwave millimeter wave security inspection device and a movable security inspection device including the electromagnetic imaging device.
  • the accuracy of manual detection is high but the efficiency is low, and the inspected person is prone to generate resistance due to physical contact.
  • Hand-held metal detectors and metal detection doors can only respond to metals, and cannot detect non-metallic dangerous goods.
  • Explosives measurement detection and liquid detectors have the disadvantages of single function and limited application.
  • the X-ray machine can only be used to detect luggage items or special places such as prisons due to X-ray ionization, and its security is easily questioned by the public. At present, the X-ray machine has been officially banned by the national environmental protection department for human security.
  • the human body security inspection equipment mainly includes an X-ray backscattered human body imaging device and a millimeter wave human body imaging device.
  • the X-ray backscattered human body imaging device uses the X-ray incident on the surface of the human body to scatter the signal for imaging,
  • the passive terahertz human security system although harmless to the human body and capable of real-time imaging, has a low signal-to-noise ratio; poor penetration, and cannot detect hidden objects under the down jacket and leather coat; and has a large device and a large footprint.
  • the active millimeter-wave security door based on three-dimensional holographic technology is also a kind of safe human body security equipment, but because it requires a mechanical scanning device, and the subject needs to stand at a specified position, follow a specified posture to stand still with security, imaging rate Generally 2-3s/person. Real-time imaging cannot be achieved, and security inspection efficiency is low. And to detect the entire human body, this device covers a large area.
  • the security inspection equipment in the prior art is not suitable for conducting secret security inspections in public places.
  • an electromagnetic imaging device for an active microwave millimeter wave security inspection device including:
  • a two-dimensional multi-transmission and multi-reception transceiver array panel which includes at least one two-dimensional multi-transmission and multi-reception transceiver sub-array, wherein each two-dimensional multi-transmission and multi-reception transceiver sub-array in the at least one two-dimensional multi-transmission and multi-reception transceiver sub-array includes linearly arranged multiple Transmitting antennas and a plurality of linearly arranged receiving antennas intersecting the linearly arranged transmitting antennas and the linearly arranged receiving antennas, wherein the plurality of transmitting antennas are configured to emit electromagnetic waves having a specific frequency, And the plurality of receiving antennas are configured to receive electromagnetic waves reflected back from the object to be inspected;
  • a signal processing device configured to reconstruct the image of the subject based on the electromagnetic waves received by the plurality of receiving antennas
  • a display device for displaying an image of the object under inspection
  • a ranging radar which is arranged on the two-dimensional multi-transmission and multi-reception transceiver array panel and is used to accurately measure the distance between the detected object and the electromagnetic imaging device,
  • the midpoint of the connection line between each of the plurality of transmission antennas and a corresponding reception antenna of the plurality of reception antennas is regarded as the pair of transmission antennas-reception antennas
  • a virtual equivalent phase center, the multiple transmit antennas and the multiple receive antennas are set to produce an equivalent phase center network
  • the distance between adjacent transmitting antennas in a plurality of transmitting antennas or adjacent receiving antennas in a plurality of receiving antennas is the wavelength of electromagnetic waves having a specific frequency
  • the distance between adjacent equivalent phase centers is in the range of 30% to 70% of the wavelength of the electromagnetic wave with a specific frequency.
  • the specific frequency is any frequency in the range of 10-300 GHz
  • the electromagnetic wave having the specific frequency is a microwave millimeter wave having a frequency in the range of 10-300 GHz.
  • a plurality of transmitting antennas are linearly arranged in two columns parallel to each other, a plurality of receiving antennas are linearly arranged in two rows parallel to each other, two columns of transmitting antennas and two rows of receiving antennas Form a rectangular or square sub-array.
  • a plurality of transmission antennas are linearly arranged in a row
  • a plurality of reception antennas are linearly arranged in a row
  • a row of transmission antennas and a row of reception antennas cross each other at their midpoints.
  • the two-dimensional multi-transmission and multi-reception transceiver array panel includes N*N two-dimensional multi-transmission and multi-reception transceiver arrays or N*M two-dimensional multi-transmission and multi-reception transceiver arrays, where N and M are greater than A positive integer equal to 1, and N is not equal to M.
  • the plurality of transmitting antennas in each two-dimensional multi-transmitting and multi-receiving sub-array are configured to sequentially emit electromagnetic waves having a specific frequency, and are located in the same position as the plurality of transmitting antennas
  • the plurality of receiving antennas in the two-dimensional multi-transmission and multi-reception sub-array are configured to receive electromagnetic waves reflected back from the subject.
  • the signal processing device reconstructs the image of the subject based on the holographic reconstruction algorithm.
  • all the transmitting antennas in the two-dimensional multi-transmission and multi-transmission array panel are configured to sequentially emit electromagnetic waves having a specific frequency
  • all All the receiving antennas in the multi-transmitting and multi-receiving sub-array are configured to receive the electromagnetic waves reflected back from the subject when each transmitting antenna emits electromagnetic waves of a specific frequency.
  • the signal processing device reconstructs the image of the inspected object based on the backward projection algorithm or the holographic reconstruction algorithm.
  • a movable security inspection apparatus including: a movable carrier; and an electromagnetic imaging apparatus according to an aspect of the present disclosure, the electromagnetic imaging apparatus being installed at On the movable carrier, wherein the length and width of the two-dimensional multi-transmission and multi-reception array panel of the electromagnetic imaging device are in the range of 10 to 100 cm; wherein, the security inspection device inspects the inspection when approaching the inspection object The area of the object corresponding to the size of the two-dimensional multi-transmission-multi-transmission array panel is scanned.
  • the movable carrier is at least one of a self-propelled device, a hand-held portable device, and a rotatable decoration installed in a public place.
  • the electromagnetic imaging device is provided with a two-dimensional multi-transmitting, multi-receiving and receiving array panel.
  • the array panel performs electrical scanning completely without mechanical scanning, enabling fast scanning and improving imaging speed. There is no artifact superposition in the image generated by the electromagnetic imaging device, and the image processing speed can be faster. Due to the characteristics of rapid scanning and rapid image reconstruction of the electromagnetic imaging device, it is possible to quickly scan a moving human body or other objects without the object being inspected being stationary.
  • the electromagnetic imaging device according to the present disclosure can be installed on a movable object or a rotatable object, and does not need to be set at a significant fixed position, so the electromagnetic imaging device is suitable for being carried around or hidden.
  • FIG. 1 shows a schematic diagram of an electromagnetic imaging device according to an embodiment of the present disclosure
  • FIG. 2 shows a schematic diagram of the arrangement of the transmitting antenna and the receiving antenna of the two-dimensional multi-transmission and multi-reception transceiver array according to an embodiment of the present disclosure
  • FIG. 3 shows a schematic diagram of an equivalent phase center network generated by the transmitting antenna and the receiving antenna shown in FIG. 2;
  • 4A and 4B respectively show schematic diagrams of the arrangement of the transmitting antennas and receiving antennas of the two-dimensional multi-transmission and multi-reception sub-array according to another embodiment of the present disclosure and the resulting equivalent phase center network;
  • 5A and 5B respectively show schematic diagrams of the arrangement of the transmitting antennas and receiving antennas of the two-dimensional multi-transmission and multi-reception sub-array according to yet another embodiment of the present disclosure and the resulting equivalent phase center network;
  • FIG. 6 shows a schematic diagram of a sub-array layout of a two-dimensional multi-transmission and multi-reception array panel according to an embodiment of the present disclosure
  • FIG. 7 shows a schematic diagram of a sub-array layout of a two-dimensional multi-transmission and multi-reception array panel according to an embodiment of the present disclosure
  • FIG. 8 shows a schematic diagram of a sub-array layout of a two-dimensional multi-transmission and multi-reception array panel according to an embodiment of the present disclosure
  • FIG. 9 shows a schematic diagram of a sub-array layout of a two-dimensional multi-transmission and multi-reception array panel according to an embodiment of the present disclosure
  • FIG. 10 shows a schematic diagram of a sub-array of a two-dimensional multi-transmission and multi-transmission array panel according to an embodiment of the present disclosure, an equivalent phase center network generated by the array panel, and an imaging plane;
  • FIG. 11 shows an application scenario of an electromagnetic imaging device according to an embodiment of the present disclosure
  • FIG. 13 shows an application scenario of an electromagnetic imaging device according to yet another embodiment of the present disclosure.
  • FIG. 1 shows an electromagnetic imaging device according to an embodiment of the present disclosure.
  • the electromagnetic imaging device is used for active security inspection equipment based on microwave millimeter waves.
  • the electromagnetic imaging device includes a two-dimensional multi-transmission and multi-reception array panel (abbreviated as: 2D MIMO array panel) 1, a signal processing device 2, a display device 3, and a ranging radar 4.
  • the two-dimensional multi-transmission and multi-transmission and reception array panel 1 includes at least one two-dimensional multi-transmission and multi-transmission and reception sub-array 11 (as shown in FIG.
  • each two-dimensional multi-transmission and multi-transmission and reception sub-array 11 includes a plurality of transmitting antennas Tx arranged linearly And a plurality of linearly arranged receiving antennas Rx (as shown in FIG. 2), the linearly arranged plurality of transmitting antennas and the linearly arranged plurality of receiving antennas intersect.
  • the crossing angle can be any angle, but the preferred crossing angle is 90°, that is, the linearly arranged receiving antenna and the linearly arranged transmitting antenna are perpendicular to each other.
  • the plurality of transmitting antennas are configured to emit electromagnetic waves having a specific frequency, and the plurality of receiving antennas are configured to receive electromagnetic waves reflected from the subject.
  • the signal processing device 2 is configured to reconstruct the image of the subject based on the electromagnetic waves received by the plurality of receiving antennas.
  • the display device 3 is used to display the image of the object to be inspected and to give an alarm when a suspicious object is recognized.
  • the equivalent position of the transmitted and received signals can be represented by the phase center of the antenna, which is the physical center of two independent antennas or apertures.
  • the receiving antenna unit and the transmitting antenna unit are set not to be in the same position, such a system where the transmitting and receiving antennas are spatially separated can be simulated using a virtual system, in the virtual system, in each pair A virtual position is added between the transmitting antenna and the receiving antenna. This position is called the equivalent phase center.
  • the midpoint of the connection line of each of the plurality of transmitting antennas and the corresponding one of the plurality of receiving antennas is regarded as the virtual of this pair of transmitting antenna-receiving antennas Equivalent phase center, where the distance between adjacent transmitting antennas or adjacent receiving antennas is one wavelength of electromagnetic waves of a specific frequency, and the distance between adjacent equivalent phase centers is 30 of the wavelength of electromagnetic waves of a specific frequency % To 70%, but preferably the distance is half the wavelength of electromagnetic waves of a specific frequency.
  • the ranging radar 4 is provided on the two-dimensional multi-transmission and multi-reception array panel and is used to accurately measure the distance between the detected object and the electromagnetic imaging device.
  • the electromagnetic waves used are microwave millimeter waves with frequencies in the range of 10-300 GHz. Waves in this band have no ionization damage to the human body and can be used for human security.
  • a two-dimensional multi-transmission and multi-reception transceiving array panel 1 is provided, and the transmitting antenna Tx in the two-dimensional multi-transmission and multi-transmission transceiving array panel 1 emits electromagnetic waves, and the receiving antenna Rx receives the electromagnetic waves, so the array panel 1 performs completely Electronic scanning, without mechanical scanning, can achieve fast scanning and improve imaging speed.
  • An equivalent phase center can be generated by a pair of transmitting antennas and a corresponding receiving antenna in the two-dimensional multi-transmitting and multi-receiving array panel, and the echo data collected by the pair of transmitting and receiving antennas can be equivalent to The echo collected by the spontaneous self-receiving antenna at the position of the equivalent phase center.
  • the transmitting antenna and the receiving antenna are arranged so that the interval between them is a wavelength of electromagnetic waves.
  • multiple transmit antennas Tx and multiple receive antennas Rx can be set to produce an equivalent phase center as shown in FIG.
  • the interval between adjacent equivalent phase centers is preferably half a wavelength. Therefore, the entire equivalent phase center network is basically a full array, and the sampling interval (that is, the equivalent phase center interval) used by the applied imaging system is on the order of ⁇ /2, so there is no false in the generated image Shadows are superimposed and can form a clearer image, so that the image processing speed can be faster.
  • the electromagnetic imaging device according to the present disclosure can quickly scan a moving human body or other objects due to its characteristics of fast scanning and fast image reconstruction, and does not require the object to be inspected to be stationary.
  • the electromagnetic imaging device 100 according to the present disclosure can be installed on a movable object or a rotatable object, and does not need to be set at a significant fixed position, so the electromagnetic imaging device is suitable for being carried around or hidden.
  • the electromagnetic imaging apparatus 100 according to the present disclosure can be installed on a mobile robot 200 that can shuttle or hide among crowds in public places, thereby performing security checks in public places.
  • FIG. 11 the electromagnetic imaging apparatus 100 according to the present disclosure can be installed on a mobile robot 200 that can shuttle or hide among crowds in public places, thereby performing security checks in public places.
  • the electromagnetic imaging device 100 according to the present disclosure can be installed on a portable security inspection device 300 that can be carried by a worker and shuttle among crowds in a public place for safety in a public place an examination.
  • the electromagnetic imaging device 100 according to the present disclosure can be mounted on a rotating table 400, and other decorative objects can also be carved on the rotating table to be presented as a decoration in a public place.
  • the electromagnetic imaging device 100 is hidden in the decoration and is not easily found by people, so that it is possible to conduct a security check in secret. Therefore, the electromagnetic imaging apparatus according to the present disclosure can secretly inspect firearms, knives, and dangerous goods such as explosives, drugs, etc. carried by terrorists in stealth mode, thereby improving safety in public places.
  • the length and width of the two-dimensional multi-transmission and multi-transmission array panel of the electromagnetic imaging device are in the range of 10 to 100 cm.
  • the electromagnetic imaging device mainly scans a portion of the object to be inspected that is easy to hide dangerous goods, such as the waist of a human body or a handbag.
  • the signal processing device 2 includes an analog signal processor 21, a digital-to-analog converter (D/A converter) 22, and a digital signal processor 23.
  • the 2D MIMO array panel will receive The microwave millimeter wave from the detected object is converted into echo data at the equivalent phase center and sent to the analog signal processor 21; the analog signal processor 21 is used to receive the analog signal from the 2D MIMO array panel And send it to the digital-to-analog converter 22; the digital-to-analog converter 22 is used to receive the signal from the analog signal processor 21, perform digital-to-analog conversion on it, and then send it to the digital signal processor 23; the digital signal processor 23 It is used to receive the information converted by the converter and reconstruct the image.
  • the image reconstruction algorithm adopted by the digital signal processor 23 will be described in detail below.
  • each sub-array 11 a plurality of transmitting antennas Tx are linearly arranged in two columns parallel to each other, and a plurality of receiving antennas Rx are linearly arranged In two rows parallel to each other, two columns of transmit antennas Tx and two rows of receive antennas Rx form a rectangular or square sub-array 11.
  • the number of transmit antennas Tx per column and the number of receive antennas Rx per row are equal, thus forming a square sub-array 11, but in other embodiments, the transmit antennas of each column and The number of receiving antennas in each row may be different from each other to form a rectangular array.
  • the square sub-array 11 in FIG. 2 produces an equivalent phase center network 11pcw as shown in FIG. 3, and in this equivalent phase center network, except for the blank space in the middle of the cross, other positions are covered with a corresponding pair
  • the virtual equivalent phase center of the transmitting antenna and the receiving antenna, and the interval ( ⁇ /2) between adjacent equivalent phase centers is the interval between adjacent transmitting antennas or adjacent receiving antennas (the interval is a wavelength ⁇ )
  • the sampling interval (that is, the equivalent phase center interval) used by the applied imaging system is on the order of about ⁇ /2, so the resulting image There is no artifact overlay.
  • a plurality of transmitting antennas are linearly arranged in a row, and a plurality of receiving antennas are linearly arranged in a row.
  • a row of transmit antennas is parallel to the edge of the array panel (such as the upper or lower edge)
  • a row of receive antennas is parallel to the other edge of the array panel, such as the left or right edge
  • the row of transmit antennas and the row of receive antennas cross each other at their midpoints.
  • the row of transmitting antennas and the row of receiving antennas can be perpendicular to each other as shown in FIG. 4A. In this case, the resulting equivalent phase center network is shown in FIG. 4B.
  • the number of multiple transmit antennas and multiple receive antennas can be the same as each other.
  • a square array distribution as shown in FIG. 2 can be obtained by intercepting the corresponding 1/4 area respectively.
  • the row of transmitting antennas and the row of receiving antennas can cross each other at their midpoints as shown in FIG. 5A, but the row of transmitting antennas is not parallel to the edge of the array panel, and the row of receiving antennas is not parallel to the edge of the array panel The sides are parallel.
  • the angle of intersection between the transmitting antenna and the receiving antenna can be 90° or other angles.
  • the resulting equivalent phase center network is shown in Figure 5B.
  • an optional transceiver array module is a 76-81 GHz chip, which has a high degree of array integration and low cost.
  • the size of the 2D MIMO array panel 1 is selected to be 20cm*20cm, and one array 11 is used (as shown in FIG. 2), and the equivalent phase center generated by it is shown in FIG.
  • the number of transmitting antennas and receiving antennas of an array panel is 96, 96 respectively.
  • the numbers of receiving antennas, transmitting antennas, and equivalent phase centers shown in FIGS. 2 and 3 are all schematic.
  • the size of the 2D MIMO array panel 1 is selected to be 20 cm*20 cm, and four sub-arrays 11 are used, and the size of each sub-array 11 is 10 cm*10 cm, as shown in FIG. 6.
  • the number of transmitting antennas and receiving antennas using a 76-81GHz chip array panel are 141 and 141, respectively.
  • the size of the 2D MIMO array panel 1 is selected to be 24 cm*24 cm, and 3*3 sub-arrays 11 are used, and the size of each sub-array 11 is 8 cm*8 cm, as shown in FIG. 7.
  • the number of transmitting antennas and receiving antennas using 76-81GHz chip array panel is 224, 224 respectively.
  • the size of the 2D MIMO array panel is 20 cm*30 cm
  • 2*3 sub-arrays 11 are used, as shown in FIG. 8.
  • the number of transmitting antennas and receiving antennas using 76-81GHz chip array panel is 188, 213 respectively.
  • 2*4 sub-arrays 11 are used, as shown in FIG. 9.
  • the number of transmitting antennas and receiving antennas using 76-81GHz chip array panel is 285, 235 respectively.
  • the transceiver array module may also be a transceiver array of other frequencies in the range of 10-300 GHz.
  • Table 1 summarizes the number of transceiver antennas used in different transceiver array sizes and in different frequency bands.
  • the side length of the antenna area array can be selected to be 10-50cm, preferably 20-40cm.
  • Table 1 shows the number of transceiver antennas used in different subarray sizes and different frequency bands for a 30cm*30cm area array.
  • the plurality of transmitting antennas Tx are configured to sequentially emit electromagnetic waves having a specific frequency
  • the plurality of receiving antennas Rx located in the same sub-array 11 as the plurality of transmitting antennas are configured In order to receive electromagnetic waves reflected back from the subject when each transmitting antenna emits electromagnetic waves. After one transmitting antenna transmits an electromagnetic wave with a specific frequency, it switches to the next transmitting antenna, and multiple receiving antennas located in the same sub-array repeat the receiving process until the entire sub-array is scanned.
  • the holographic reconstruction algorithm described below can be used to perform real-time image reconstruction.
  • all the transmitting antennas Tx in the two-dimensional multi-transmitting multi-receiving array panel are configured to sequentially emit electromagnetic waves with a specific frequency
  • all The receiving antenna Rx is configured to simultaneously receive the electromagnetic waves reflected from the subject. That is to say, after one transmitting antenna emits electromagnetic waves with a specific frequency, it switches to the next transmitting antenna, and all receiving antennas in the array panel repeat the receiving process to obtain all scattering data at different viewing angles of the detected object.
  • the 2D MIMO array panel 1 includes only one sub-array 11, the holographic reconstruction algorithm described below can still be used for image reconstruction. In the case where the 2D MIMO array panel 1 includes multiple sub-arrays 11, it is necessary to use the backward projection algorithm to be described below for reconstruction.
  • Holographic re-algorithm can realize the real-time reconstruction of the object image.
  • the echo data collected by a pair of transceiver antennas can be equivalent to the echo collected by the spontaneous self-receiving antenna at the position of the equivalent phase center.
  • the signal processing device collects the echo data at the center of the equivalent phase. Assuming that the collected reflection data of the detected object is s(n x , n y ), the reflection data is corrected using the following formula to obtain the corrected reflection data matrix :
  • s(n x , n y ) is the uncorrected scattering data matrix
  • n x and n y are the indices of the rows and columns in the equivalent phase center network.
  • a reference point representing the center of the imaging area j represents an imaginary number
  • k represents a spatial constant
  • R u (n x , n y ) represents the calculated reflection set.
  • the following objects are sampled as shown in Figure 10. Point scatterer.
  • R o (n x , n y ) represents the calculated reflection set, where the calculated reflection set is obtained in the case of sampling the equivalent phase center network of the multi-reception and multi-transmission aperture (as shown in FIG. 10 ).
  • I(x, y) represents the scattering coefficient of the detected object
  • z 0 represents the distance between the 2D MIMO array panel and the detected object
  • j represents the imaginary number
  • k is the propagation constant
  • k x , k y are the spatial propagation Constant
  • FFT 2D is a two-dimensional Fourier transform
  • IFFT 2D is a two-dimensional inverse Fourier transform.
  • the collected echo data can be expressed as s(n x , n y ).
  • the synthetic aperture holographic algorithm based on fast Fourier change fast reconstruction can be achieved and imaging can be completed.
  • the purpose of the imaging algorithm is to invert the image of the detected object from the echo expression, that is, the scattering coefficient I(x, y) of the detected object.
  • the synthetic aperture holographic algorithm based on Fourier transform does not need to be like the subsequent projection algorithm The entire imaging area is reconstructed point by point, but the advantages of fast Fourier transform are used to reconstruct the correct imaging area at one time. Therefore, the algorithm can realize fast scanning and fast image reconstruction, thus real-time imaging.
  • the image reconstructed by the reconstruction algorithm is displayed on the display device, and the suspicious object alarm algorithm is combined to alarm the suspicious object.
  • the present disclosure can also employ a backward projection algorithm to perform image reconstruction on the inspected object.
  • Backward projection originated from computer tomography technology is an accurate imaging algorithm based on time-domain signal processing. The basic idea is that for each imaging point in the imaging area, by calculating the delay between the point and the receiving and transmitting antennas, the contributions of all echoes to it are coherently superimposed to obtain the corresponding pixel value of the point in the image. In this way, the entire imaging area is coherently superimposed point by point to obtain an image of the imaging area.
  • the biggest disadvantage of this algorithm is that it needs to reconstruct every point in the entire imaging interval, which is slow and takes a long time.
  • the backward projection algorithm is naturally easy to implement parallel computing, so it is suitable for the case where the receiving antennas in multiple sub-arrays simultaneously receive the reflected electromagnetic waves.
  • the reconstruction speed is slow and time-consuming, but if the hardware in the processing system uses GPU or FPGA technology, the reconstruction time can be greatly reduced, and even real-time reconstruction can be achieved.
  • z a is the imaging distance (the distance is measured by the ranging radar)
  • j is an imaginary unit
  • k is the propagation constant
  • the echo signal of the detected object is received
  • (x t , y t ) is the transmitting antenna coordinate
  • (x r , y r ) is the receiving antenna coordinate
  • z represents the 2D MIMO array panel
  • the distance to a certain fault of the inspected object (where the minimum value of this distance is the distance between the 2D MIMO array panel and the front surface of the inspected object, which is measured by the ranging radar); where s(x t , y t , x r , y r , k) is calculated by the following formula:
  • the image reconstructed by the reconstruction algorithm is displayed on the display device 3, and in combination with the suspicious object alarm algorithm, the suspicious object is alerted.

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Electromagnetism (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geophysics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geology (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

一种用于主动式微波毫米波安检设备的电磁成像装置，包括：二维多发多收收发阵列面板(1)，其包括至少一个子阵列(11)，其中每个子阵列(11)包括线性排列的多个发射天线(Tx)和线性排列的多个接收天线(Rx)，线性排列的多个发射天线(Tx)和线性排列的多个接收天线(Rx)相交；信号处理装置(2)；显示装置(3)；以及测距雷达(4)。在每个子阵列(11)中，每个发射天线(Tx)和相应一个接收天线(Rx)的连线的中点被看作这对发射天线-接收天线的虚拟的等效相位中心，多个发射天线(Tx)和多个接收天线(Rx)被设置为产生等效相位中心网；相邻的发射天线(Tx)或相邻的接收天线(Rx)之间的距离为特定频率的电磁波的一个波长，在所产生的等效相位中心网中，相邻的等效相位中心之间的距离在特定频率的电磁波的波长的30％至70％的范围内。

Description

用于主动式微波毫米波安检设备的电磁成像装置
本申请要求于2018年12月29日递交中国专利局的、申请号为201811654199.4的中国专利申请的权益，这些申请的全部公开内容以引用方式并入本文。
技术领域
本公开涉及一种电磁成像装置，更具体地涉及一种用于主动式微波毫米波安检设备的电磁成像装置和一种包括该电磁成像装置的可移动式安检设备。
背景技术
目前，国际公共安全技术主要包括人工检查、手持金属探测器、金属探测器门、X光机、爆炸物衡量探测、液体检测仪等。
人工检测准确度高但是效率低，且被检人员由于身体接触容易产生抵触情绪。手持金属探测器和金属探测门只能对金属响应，无法对非金属危险品进行探测。爆炸物衡量探测和液体检测仪都存在功能单一、应用局限的缺点。X光机由于X射线具有致电离性，只能用来检测行李物品，或者监狱等特殊场所，其在安全性方面易受到公众质疑。目前，X光机已经正式被国家环保部门禁止用于人体安检。
人体安检设备主要包含X射线背散射人体成像装置和毫米波人体成像装置。X射线背散射人体成像装置利用X射线入射到人体表面散射回来的信号进行成像，
因此，传统的X光机、金属探测器或者搜身等检查模式无法实施、动态干涉潜在的危险，已经不能满足当前日益严峻和复杂的安检形式。被动式太赫兹人体安检系统，虽然对人体无害且能够实现实时成像，但是图像信噪比低；穿透性差，无法探测羽绒服和皮衣下面的隐匿物品；并且装置大，占地空间大。基于三维全息技术的主动式毫米波安检门，也是一种安全的人体安检设备，但是由于其需要机械扫描装置，且需要被检人在指定的位置，遵循指定的姿势静止站立配合安检，成像速率一般为2-3s/人。无法实现实时成像，安检效率低。并且要对整个人体进行检测，这个装置占地面积大。
因此，现有技术中的安检设备都不适于在公共场合进行隐秘式的安全检查。
发明内容
根据本公开的一方面，提供一种用于主动式微波毫米波安检设备的电磁成像装置，包括：
二维多发多收收发阵列面板，其包括至少一个二维多发多收收发子阵列，其中至少一个二维多发多收收发子阵列中的每个二维多发多收收发子阵列包括线性排列的多个发射天线和线性排列的多个接收天线，所述线性排列的多个发射天线和所述线性排列的多个接收天线相交，其中所述多个发射天线被构造为发射具有特定频率的电磁波，且所述多个接收天线被构造为接收从被检对象反射回的电磁波；
信号处理装置，其被构造为基于所述多个接收天线接收的电磁波重建被检对象的图像；
显示装置，其用于显示被检对象的图像；以及
测距雷达，其设置于所述二维多发多收收发阵列面板上且用于精确地测量被检对象和电磁成像装置之间的距离，
其中，在每个子阵列中，所述多个发射天线中的每个发射天线和所述多个接收天线中的一个相应接收天线的连线的中点被看作这一对发射天线-接收天线的虚拟的等效相位中心，所述多个发射天线和所述多个接收天线被设置为产生等效相位中心网；
多个发射天线中的相邻的发射天线或多个接收天线中的相邻的接收天线之间的距离为具有特定频率的电磁波的波长，
在所产生的等效相位中心网中，相邻的等效相位中心之间的距离在具有特定频率的电磁波的波长的30％至70％的范围内。
根据本公开的一个示例性实施例，所述特定频率为10-300GHz范围内的任一频率，具有特定频率的电磁波为频率在10-300GHz范围内的微波毫米波。
根据本公开的一个示例性实施例，每个子阵列中，多个发射天线线性排列成彼此平行的两列，多个接收天线线性排列成彼此平行的两行，两列发射天线和两行接收天线构成一个矩形或正方形子阵列。
根据本公开的一个示例性实施例，在每个子阵列中，多个发射天线线性排列成一行，多个接收天线线性排列成一行，一行发射天线和一行接收天线在其中点处相互交叉。
根据本公开的一个示例性实施例，二维多发多收收发阵列面板包括N*N个二维多发多收收发子阵列或N*M个二维多发多收收发子阵列，N、M为大于等于1的正整数，且N不等于M。
根据本公开的一个示例性实施例，每个二维多发多收收发子阵列中的所述多个发射天线被构造为依次发射具有特定频率的电磁波，且与所述多个发射天线位于同一个二维多发多收收发子阵列中的多个接收天线被构造为接收从被检对象反射回的电磁波。在该实施例中，所述信号处理装置基于全息重建算法重建被检对象的图像。
根据本公开的一个示例性实施例，二维多发多收收发阵列面板中的所有发射天线被构造为依次发射具有特定频率的电磁波，且位于所述二维多发多收收发阵列面板的所有二维多发多收收发子阵列中的所有接收天线被构造为在每个发射天线发射特定频率的电磁波时接收从被检对象反射回的电磁波。在该实施例中，所述信号处理装置基于后向投影算法或全息重建算法重建被检对象的图像。
根据本公开的另一方面，提供一种可移动式安检设备，所述可移动式安检设备包括：可移动载体；以及根据本公开的一方面的电磁成像装置，所述电磁成像装置安装在所述可移动载体上，其中，所述电磁成像设备的二维多发多收收发阵列面板的长度和宽度均在10至100cm的范围内；其中，所述安检设备在靠近被检对象时对被检对象的对应于所述二维多发多收收发阵列面板的尺寸的区域进行扫描。
根据本公开的一个示例性实施例，所述可移动载体是自走式装置、手提便携式装置和安装在公共场所的可旋转装饰物中的至少一个。
根据本公开的电磁成像装置设置有二维多发多收收发阵列面板，该阵列面板完全进行电扫描，无需进行机械扫描，能够实现快速扫描，提高成像速度。该电磁成像装置产生的图像中不存在伪影叠加，图像处理的速度能够更快。由于该电磁成像装置的快速扫描和快速图像重建的特征，能够对移动的人体或其他物体进行快速的扫描，不需要被检对象静止。根据本公开的电磁成像装置能够安装在可移动物体或可旋转物体上，无需被设置于显著的固定位置，因此该电磁成像装置适于被随身携带或隐藏地设置。
附图说明
图1示出了根据本公开的一个实施例的电磁成像装置的示意图；
图2示出了根据本公开的一个实施例的二维多发多收收发子阵列的发射天线和接收天线的排列方式的示意图；
图3示出了如图2所示的发射天线和接收天线产生的等效相位中心网的示意图；
图4A和4B分别示出了根据本公开的另一实施例的二维多发多收收发子阵列的发 射天线和接收天线的排列方式和产生的等效相位中心网的示意图；
图5A和5B分别示出了根据本公开的又一实施例的二维多发多收收发子阵列的发射天线和接收天线的排列方式和产生的等效相位中心网的示意图；
图6示出了根据本公开的一个实施例的二维多发多收收发阵列面板的子阵列布局示意图；
图7示出了根据本公开的一个实施例的二维多发多收收发阵列面板的子阵列布局示意图；
图8示出了根据本公开的一个实施例的二维多发多收收发阵列面板的子阵列布局示意图；
图9示出了根据本公开的一个实施例的二维多发多收收发阵列面板的子阵列布局示意图；
图10示出了根据本公开的一个实施例的二维多发多收收发阵列面板的一个子阵列、该阵列面板所产生的等效相位中心网和成像平面的示意图；
图11示出了根据本公开的一个实施例的电磁成像装置的一种应用场景；
图12示出了根据本公开的另一实施例的电磁成像装置的一种应用场景；以及
图13示出了根据本公开的又一实施例的电磁成像装置的一种应用场景。
具体实施方式
尽管本公开的容许各种修改和可替换的形式，但是它的具体的实施例通过例子的方式在附图中示出，并且将详细地在本文中描述。然而，应该理解，随附的附图和详细的描述不是为了将本公开的限制到公开的具体形式，而是相反，是为了覆盖落入由随附的权利要求限定的本公开的精神和范围中的所有的修改、等同形式和替换形式。附图是为了示意，因而不是按比例地绘制的。
在本说明书中使用了“上”、“下”、“左”、“右”等术语，并不是为了限定元件的绝对方位，而是为了描述元件在视图中的相对位置帮助理解；本说明书中“顶侧”和“底侧”是相对于一般情况下，物体正立的上侧和下侧的方位；“第一”、“第二”等也不是为了排序，而是为了区别不同部件。
下面参照附图描述根据本公开的多个实施例。
图1示出了根据本公开的一个实施例的电磁成像装置。该电磁成像装置用于基于微波毫米波的主动式安检设备。该电磁成像装置包括：二维多发多收收发阵列面板(简 称为：2D MIMO阵列面板)1，信号处理装置2，显示装置3以及测距雷达4。二维多发多收收发阵列面板1包括至少一个二维多发多收收发子阵列11(如图2所示)，其中每个二维多发多收收发子阵列11包括线性排列的多个发射天线Tx和线性排列的多个接收天线Rx(如图2所示)，所述线性排列的多个发射天线和所述线性排列的多个接收天线相交。该交叉角度能够是任意角度，但优选的交叉角度是90°，即线性排列的接收天线和线性排列的发射天线彼此垂直。所述多个发射天线被构造为发射具有特定频率的电磁波，且所述多个接收天线被构造为接收从被检对象反射回的电磁波。信号处理装置2被构造为基于所述多个接收天线接收的电磁波重建被检对象的图像。显示装置3用于显示被检对象的图像且在识别出可疑物体时进行报警。在每个子阵列中，发射和接收信号的等效位置可以由天线的相位中心来表示，该等效位置为两个独立天线或孔径的物理中心。在本公开的实施例中，接收天线单元和发射天线单元被设置为不处于同一位置，这种发射和接收天线空间分离的系统可以使用一个虚拟的系统模拟，在虚拟系统中，在每一对发射天线与接收天线之间添加一个虚拟位置，这个位置被称为等效相位中心(phase center)。在本公开中，所述多个发射天线中的每个发射天线和所述多个接收天线中的相应一个接收天线的连线的中点被看作这一对发射天线-接收天线的虚拟的等效相位中心，其中相邻的发射天线或相邻的接收天线之间的距离为特定频率的电磁波的一个波长，相邻的等效相位中心之间的距离在特定频率的电磁波的波长的30％至70％的范围内，但是优选地该距离为特定频率的电磁波的波长的一半。测距雷达4设置于所述二维多发多收收发阵列面板上且用于精确地测量被检对象和电磁成像装置之间的距离。
在本公开中，采用的电磁波是频率在10-300GHz范围内的微波毫米波。该波段的波对人体没有电离损伤，可用于人体安检。在本公开中，设置一个二维多发多收收发阵列面板1，该二维多发多收收发阵列面板1中的发射天线Tx发射电磁波，并且接收天线Rx接收该电磁波，因此该阵列面板1完全进行电扫描，无需进行机械扫描，能够实现快速扫描，提高成像速度。通过该二维多发多收收发阵列面板中的一对发射天线和一个相应的接收天线能够产生一个等效相位中心(phase center)，一对收发天线组合所采集的回波数据可以等效为其等效相位中心所在位置处的自发自收天线所采集的回波。发射天线和接收天线排列成使得它们之间的间隔是电磁波的一个波长。在二维多发多收收发阵列面板所包含的如图2所示的每个子阵列11中，多个发射天线Tx和多个接收天线Rx能够被设置为产生如图3所示的等效相位中心网11pcw，在该等效相位中心网中， 相邻的等效相位中心的间隔优选地为半波长。因此，整个等效相位中心网基本上为一满阵，且应用的成像系统采用的取样间隔(即等效相位中心的间隔)在λ/2左右的量级，因此产生的图像中不存在伪影叠加且能够形成较清晰的图像，从而图像处理的速度能够更快。
根据本公开的电磁成像装置由于其快速扫描和快速图像重建的特征，能够对移动的人体或其他物体进行快速的扫描，不需要被检对象静止。根据本公开的电磁成像装置100能够安装在可移动物体或可旋转物体上，无需被设置于显著的固定位置，因此该电磁成像装置适于被随身携带或隐藏地设置。如图11所示，根据本公开的电磁成像装置100能够安装在可移动机器人200上，该可移动机器人可以在公共场合的人群中穿梭或者隐藏起来，从而在公共场合进行安全检查。此外，如图12所示，根据本公开的电磁成像装置100能够安装在便携式安检装置300上，该便携式安检装置300可以由工作人员携带，在公共场合的人群中穿梭，从而在公共场合进行安全检查。此外，如图13所示，根据本公开的电磁成像装置100能够安装在旋转台400上，并且在该旋转台上还可以雕刻其他装饰物，从而作为公共场合的一个装饰而呈现出来。电磁成像装置100被隐藏在该装饰物中，不易被人发现，从而能够隐秘地进行安全检查。因此，根据本公开的电磁成像装置能够隐秘地对恐怖分子利用隐匿方式随身携带的枪支、刀具以及爆炸物、毒品等危险品进行检查，从而提高公共场合的安全性。
在上述的三种应用场景中，所述电磁成像设备的二维多发多收收发阵列面板的长度和宽度均在10至100cm的范围内。该电磁成像设备主要对被检对象的容易藏匿危险物品的部位进行扫描，例如人体的腰部或手提袋等进行扫描。
在本公开的一个示例性实施例中，所述信号处理装置2包括模拟信号处理器21，数模转换器(D/A转换器)22，数字信号处理器23。2D MIMO阵列面板将所接收的来自被检对象的微波毫米波转化为等效相位中心上的回波数据，并将其发送至模拟信号处理器21；模拟信号处理器21用于接收该2D MIMO阵列面板传来的模拟信号，并将其发送至数模转换器22；数模转换器22用于接收来自模拟信号处理器21的信号，并对其进行数模转换再发送至数字信号处理器23；数字信号处理器23用于接收经转换器转换后的信息，并对其进行图像重建，该数字信号处理器23所采用的图像重建算法在下文中将详细说明。
在根据本公开的电磁成像装置的一个示例性实施例中，如图2所示，在每个子阵列11中，多个发射天线Tx线性排列成彼此平行的两列，多个接收天线Rx线性排列成彼此 平行的两行，两列发射天线Tx和两行接收天线Rx构成一个矩形或正方形子阵列11。在如图2所示的示例性实施例中，每列发射天线Tx的数量和每行接收天线Rx的数量相等，因此构成一个正方形子阵列11，但是在其他实施例中，每列发射天线和每行接收天线的数量可以彼此不同，以构成矩形阵列。图2中的正方形子阵列11产生如图3所示的等效相位中心网11pcw，在该等效相位中心网，除了中间十字形的空白之处外，其他位置都布满了相应的一对发射天线和接收天线的虚拟等效相位中心，且相邻的等效相位中心的间隔(λ/2)为相邻的发射天线或相邻的接收天线之间的间隔(该间隔为一个波长λ)的大约一半，因此该等效相位中心网11pcw几乎为一满阵，应用的成像系统采用的取样间隔(即等效相位中心的间隔)在大约λ/2的量级，因此产生的图像中不存在伪影叠加。
在根据本公开的一个示例性实施例中，如图4A和图5A所示，在每个子阵列中，多个发射天线线性排列成一行，多个接收天线线性排列成一行。一行发射天线平行于阵列面板的边缘(例如上或下边缘)，一行接收天线平行于阵列面板的另一边缘，例如左或右边缘，且一行发射天线和一行接收天线在其中点处相互交叉。该一行发射天线和一行接收天线能够如图4A所示相互垂直，在此情况下，产生的等效相位中心网如图4B所示。
在一个实施例中，在如图4A的排列方式中，多个发射天线和多个接收天线数量能够彼此相同。在该实施例中，在相邻的四个如图4A所示的子阵列组成的阵列中，通过分别截取相应的1/4区域，可以得到如图2所示的正方形阵列分布。
在另一实施例中，该一行发射天线和一行接收天线能够如图5A所示在其中点处相互交叉，但是一行发射天线不与阵列面板的边缘平行，一行接收天线也不与阵列面板的缘边平行。发射天线和接收天线之间的相交角度能够是90°或90°之外的其他角度。在此情况下，所产生的等效相位中心网如图5B所示。
在一个实施例中，一种可选的收发阵列模块是76-81GHz芯片，阵列集成程度高，成本低。2D MIMO阵列面板1尺寸选择为20cm*20cm，采用1块阵列11(如图2所示)，其所产生的等效相位中心如图3所示。采用76-81GHz芯片，1个阵列面板发射天线和接收天线数目分别为96，96。本领域的技术人员应当理解，如图2和图3中所示的接收天线、发射天线以及等效相位中心的数量都是示意性的。
在一个实施例中，2D MIMO阵列面板1尺寸选择为20cm*20cm，采用4块子阵列11，每个子阵11的大小为10cm*10cm，如图6所示。采用76-81GHz芯片阵列面板发射 天线和接收天线数目分别为141，141。
在一个实施例中，2D MIMO阵列面板1尺寸选择为24cm*24cm，采用3*3块子阵列11，每个子阵11的大小为8cm*8cm，如图7所示。采用76-81GHz芯片阵列面板发射天线和接收天线数目分别为224，224。
在一个实施例中，2D MIMO阵列面板尺寸为20cm*30cm时，采用2*3块子阵列11，如图8所示。采用76-81GHz芯片阵列面板发射天线和接收天线数目分别为188，213。
在一个实施例中，2D MIMO阵列面板尺寸为20cm*40cm时，采用2*4块子阵列11，如图9所示。采用76-81GHz芯片阵列面板发射天线和接收天线数目分别为285，235。
在本公开中，除了采用上述的76-81GHz收发阵列模块，收发阵列模块也可以是10-300GHz范围内的其他频率的收发阵列。表1总结了不同收发阵列尺寸下和不同频段下所使用的收发天线的数目。天线面阵边长可选择为10-50cm，优选20-40cm，表1示出了对于30cm*30cm的面阵，在不同子阵大小和不同频段下所采用的收发天线数目。
表1
Figure PCTCN2019110381-appb-000001
Figure PCTCN2019110381-appb-000002
*给出的是中心频率
在根据本公开的一个实施例中，所述多个发射天线Tx被构造为依次发射具有特定频率的电磁波，且与所述多个发射天线位于同一子阵列11中的多个接收天线Rx被构造为在每个发射天线发射电磁波时，接收从被检对象反射回的电磁波。在一个发射天线发射具有特定频率的电磁波之后，切换到下一个发射天线，位于同一子阵列中的多个接收天线重复该接收过程，直到完成整个子阵列的扫描。在一个子阵列11完成扫描之后，在可选的情况下，切换到下一个子阵列，直到完成整个阵列面板的所有子阵列的扫描，以获得被检对象不同视角的所有散射数据。在这种扫描模式下，可以采用下文将描述的全息重建算法来进行实时的图像重建。
在根据本公开的一个实施例中，二维多发多收收发阵列面板中的所有发射天线Tx被构造为依次发射具有特定频率的电磁波，且位于所述二维多发多收收发阵列面板中的所有接收天线Rx被构造为同时接收从被检对象反射回的电磁波。也就是说，在一个发射天线发射具有特定频率的电磁波之后，切换到下一个发射天线，阵列面板中的所有接收天线重复接收过程，以获得被检对象不同视角的所有散射数据。在此实施例中，若2D MIMO阵列面板1仅仅包括一个子阵列11，那么依旧可以采用下文将描述的全息重建算法来进行图像重建。在2D MIMO阵列面板1包括多个子阵列11的情况下，需要采用下文将要描述的后向投影算法进行重建。
全息重新算法可以实现对被检物图像的实时重建。一对收发天线组合所采集的回波数据可以等效为其等效相位中心所在位置处的自发自收天线所采集的回波。信号处理装置对等效相位中心处的回波数据进行采集，假设所采集的被检对象的反射数据为s(n x，n y)，利用如下公式校正反射数据，得到校正后的反射数据矩阵：
Figure PCTCN2019110381-appb-000003
其中s(n x，n y)为未校正的散射数据矩阵，n x和n y是等效相位中心网中的行和列的指数。
R u(n x，n y)与R o(n x，n y)计算公式如下，
Figure PCTCN2019110381-appb-000004
且
Figure PCTCN2019110381-appb-000005
其中，如图10所示，
Figure PCTCN2019110381-appb-000006
表示成像区域的中心的参考点，j表示虚数，k表示空间常数。
R u(n x，n y)表示计算的反射集，在此情况下，如图10所示对如下的被检对象进行采样，被检对象包含一个定位在
Figure PCTCN2019110381-appb-000007
处的点散射体。
R o(n x，n y)表示计算的反射集，其中在对多收多发孔径的等效相位中心网进行采样(如图10所示)的情况下，得到该计算的反射集。
然后利用二维傅里叶变换算法重建，获得被检对象的散射系数：
Figure PCTCN2019110381-appb-000008
其中，I(x，y)表示被检对象的散射系数，z 0表示2D MIMO阵列面板和被检对象之间的距离，j表示虚数，k为传播常数、k x、k y分别是空间传播常数；FFT 2D为二维傅里叶变换，IFFT 2D为二维傅里叶逆变换。
完成二维孔径扫描后，采集到的回波数据可以表示为s(n x，n y)。最后，结合基于快速傅里叶变化的合成孔径全息算法，可以实现快速重建，完成成像。成像算法的目的就是从回波表达式中反演出被检对象的像，即被检对象的散射系数I(x，y)，基于傅里叶变换的合成孔径全息算法，无需像后续投影算法一样对整个成像区域逐点重建，而是利用快速傅里叶变换的优势，一次对正确成像区域重建完成。因此，该算法能够实现快速扫描和快速图像重建，因此实现实时成像。重建算法重建所得图像显示在显示装置上，结合可疑物报警算法，对可疑物进行报警。
此外，本公开还可以采用后向投影算法对被检对象进行图像重建。后向投影起源于计算机断层扫描技术是一种基于时域信号处理的精确的成像算法。其基本思想是对成像区域内每一成像点，通过计算该点到收、发天线之间的延时，将所有回波对它的贡献相干叠加从而得到该点在图像中对应的像素值，这样对整个成像区域逐点地进行 相干叠加处理，即可获得成像区域的图像。这种算法最大的缺点是需要对整个成像区间每一个点重建，重建速度慢，耗时长。
但是后向投影算法天然的易于实现并行计算，因此，适用于多个子阵列中的接收天线同时接收反射的电磁波的情况。虽然需要对整个成像区间每一个点重建，重建速度慢，耗时长，但是如果处理系统中的硬件采用GPU或者FPGA技术的话，重建时间可以大大降低，甚至实现实时重建。
图像重建的公式为：
Figure PCTCN2019110381-appb-000009
其中，
Figure PCTCN2019110381-appb-000010
是被检对象的散射系数，z a是成像距离(该距离由测距雷达测得)，j为虚数单位，k为传播常数，s(x t，y t，x r，y r，k)为一对发射天线-接收天线组合接收到被检对象的回波信号，(x t，y t)为发射天线坐标，(x r，y r)为接收天线的坐标；z表示2D MIMO阵列面板和被检对象的某一断层之间的距离(其中，该距离的最小值为2D MIMO阵列面板与被检物前表面的距离，该距离由测距雷达测得)；其中s(x t，y t，x r，y r，k)通过如下的公式计算：
Figure PCTCN2019110381-appb-000011
通过重建算法而重建的图像显示在显示装置3上，结合可疑物报警算法，对可疑物进行报警。
虽然本总体专利构思的一些实施例已被显示和说明，本领域普通技术人员将理解，在不背离本总体专利构思的原则和精神的情况下，可对这些实施例做出改变，本公开的范围以权利要求和它们的等同物限定。

Claims (11)

  1. 一种用于主动式微波毫米波安检设备的电磁成像装置，包括：
    二维多发多收收发阵列面板，其包括至少一个二维多发多收收发子阵列，其中至少一个二维多发多收收发子阵列中的每个二维多发多收收发子阵列包括线性排列的多个发射天线和线性排列的多个接收天线，所述线性排列的多个发射天线和所述线性排列的多个接收天线相交，其中所述多个发射天线被构造为发射具有特定频率的电磁波，且所述多个接收天线被构造为接收从被检对象反射回的电磁波；
    信号处理装置，其被构造为基于所述多个接收天线接收的电磁波重建被检对象的图像；
    显示装置，其用于显示被检对象的图像；以及
    测距雷达，其设置于所述二维多发多收收发阵列面板上且用于精确地测量被检对象和电磁成像装置之间的距离，
    其中，在每个子阵列中，所述多个发射天线中的每个发射天线和所述多个接收天线中的一个相应的接收天线的连线的中点被看作这一对发射天线-接收天线的虚拟的等效相位中心，所述多个发射天线和所述多个接收天线被设置为产生等效相位中心网；
    多个发射天线中的相邻的发射天线或多个接收天线中的相邻的接收天线之间的距离为具有特定频率的电磁波的波长，在所产生的等效相位中心网中，相邻的等效相位中心之间的距离在具有特定频率的电磁波的波长的30％至70％的范围内。
  2. 根据权利要求1所述的电磁成像装置，其特征在于，所述特定频率为10-300GHz范围内的任一频率，具有特定频率的电磁波为频率在10-300GHz范围内的微波毫米波。
  3. 根据权利要求1至2中任一项所述的电磁成像装置，其特征在于，每个子阵列中，多个发射天线线性排列成彼此平行的两列，多个接收天线线性排列成彼此平行的两行，两列发射天线和两行接收天线构成一个矩形或正方形子阵列。
  4. 根据权利要求1至2中任一项所述的电磁成像装置，其特征在于，在每个子阵列中，多个发射天线线性排列成一行，多个接收天线线性排列成一行，一行发射天线和一行接收天线在其中点处相互交叉。
  5. 根据权利要求1至4中任一项所述的电磁成像装置，其特征在于，二维多发多收收发阵列面板包括N*N个二维多发多收收发子阵列或N*M个二维多发多收收发子阵列，N、M为大于等于1的正整数，且N不等于M。
  6. 根据权利要求1至5中任一项所述的电磁成像装置，其特征在于，每个二维多发多收收发子阵列中的多个发射天线被构造为依次发射具有特定频率的电磁波，且
    与所述多个发射天线位于同一个二维多发多收收发子阵列中的多个接收天线被构造为接收从被检对象反射回的电磁波。
  7. 根据权利要求1至5中任一项所述的电磁成像装置，其特征在于，二维多发多收收发阵列面板中的所有发射天线被构造为依次发射具有特定频率的电磁波，且
    位于所述二维多发多收收发阵列面板的所有二维多发多收收发子阵列中的所有接收天线被构造为在每个发射天线发射特定频率的电磁波时接收从被检对象反射回的电磁波。
  8. 根据权利要求6所述的电磁成像装置，其特征在于，所述信号处理装置基于全息重建算法重建被检对象的图像。
  9. 根据权利要求7所述的电磁成像装置，其特征在于，所述信号处理装置基于后向投影算法或全息重建算法重建被检对象的图像。
  10. 一种可移动式安检设备，包括：
    可移动载体；以及
    根据权利要求1所述的电磁成像装置，所述电磁成像装置安装在所述可移动载体上，
    其中，所述电磁成像设备的二维多发多收收发阵列面板的长度和宽度均在10至100cm的范围内；
    其中，所述安检设备在靠近被检对象时对被检对象的对应于所述二维多发多收收发阵列面板的尺寸的区域进行扫描。
  11. 根据权利要求10所述的安检设备，其中，所述可移动载体是自走式装置、手提便携式装置和安装在公共场所的可旋转装饰物中的至少一个。
PCT/CN2019/110381 2018-12-29 2019-10-10 用于主动式微波毫米波安检设备的电磁成像装置 Ceased WO2020134335A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/309,915 US12339352B2 (en) 2018-12-29 2019-10-10 Electromagnetic imaging device for active microwave and millimeter wave security inspection apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201811654199.4A CN109828241B (zh) 2018-12-29 2018-12-29 用于主动式微波毫米波安检设备的电磁成像装置
CN201811654199.4 2018-12-29

Publications (1)

Publication Number Publication Date
WO2020134335A1 true WO2020134335A1 (zh) 2020-07-02

Family

ID=66860716

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/110381 Ceased WO2020134335A1 (zh) 2018-12-29 2019-10-10 用于主动式微波毫米波安检设备的电磁成像装置

Country Status (3)

Country Link
US (1) US12339352B2 (zh)
CN (1) CN109828241B (zh)
WO (1) WO2020134335A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113156433A (zh) * 2021-05-07 2021-07-23 南京邮电大学 一种微波成像装置

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9667290B2 (en) * 2015-04-17 2017-05-30 Apple Inc. Electronic device with millimeter wave antennas
CN109799538B (zh) 2018-12-29 2024-10-18 清华大学 安检设备及其控制方法
CN109828241B (zh) 2018-12-29 2024-01-26 清华大学 用于主动式微波毫米波安检设备的电磁成像装置
CN110609330B (zh) * 2019-09-06 2021-03-26 北京理工大学 一种稀疏阵列实波束电扫描快速成像系统
US12613330B2 (en) 2020-06-25 2026-04-28 Lassen Peak, Inc. Systems and methods for using a conducted energy weapon in conjunction with a noninvasive detection of impermissible objects
US12405367B2 (en) 2020-06-25 2025-09-02 Lassen Peak, Inc. Systems and methods for noninvasive detection of impermissible objects
US12529781B2 (en) 2020-06-25 2026-01-20 Lassen Peak, Inc. Systems and methods for noninvasive detection of impermissible objects using decoupled analog and digital components
CN112130167A (zh) * 2020-07-03 2020-12-25 北京中电科卫星导航系统有限公司 一种移动式毫米波人体安检系统
CN111660301A (zh) * 2020-07-06 2020-09-15 上海亨临光电科技有限公司 一种集成式安防巡检机器人
CN112099101B (zh) * 2020-08-13 2022-02-22 西安电子科技大学 一种用于毫米波安检成像的稀疏天线阵列布局设计
CN112201032A (zh) * 2020-08-28 2021-01-08 武汉理工大学 一种道路车流监测方法、存储介质及系统
CN119355829A (zh) * 2020-10-28 2025-01-24 清华大学 毫米波人体安检系统和方法
US12099360B2 (en) 2020-12-16 2024-09-24 Lassen Peak, Inc. Systems and methods for noninvasive aerial detection of impermissible objects
US12000924B2 (en) 2021-01-06 2024-06-04 Lassen Peak, Inc. Systems and methods for noninvasive detection of impermissible objects
US11982734B2 (en) 2021-01-06 2024-05-14 Lassen Peak, Inc. Systems and methods for multi-unit collaboration for noninvasive detection of concealed impermissible objects
CN112859072A (zh) * 2021-01-20 2021-05-28 北京环境特性研究所 一种基于平面mimo阵列的雷达系统及三维成像方法
CN116500605A (zh) * 2021-12-31 2023-07-28 北京神目科技有限公司 用于毫米波收发的阵列面板、安检设备及其控制方法
CN116125469B (zh) * 2023-02-24 2025-12-19 深圳市奥谱毫芯技术合伙企业(有限合伙) 一种3d微波近场成像方法、装置、系统及其介质

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007054685A2 (en) * 2005-11-09 2007-05-18 Qinetiq Limited Passive detection apparatus
CN103616667A (zh) * 2013-11-20 2014-03-05 中国电子科技集团公司第四十一研究所 一种用于散射成像的二维天线阵列布置方法
CN104808201A (zh) * 2015-04-23 2015-07-29 中国电子科技集团公司第四十一研究所 一种二维mimo阵列实现方法
CN106093898A (zh) * 2016-08-23 2016-11-09 中国电子科技集团公司第四十研究所 一种分区域式的mimo阵列校准方法
CN206209131U (zh) * 2016-07-26 2017-05-31 华讯方舟科技有限公司 基于毫米波成像的便携式安检设备
CN108761452A (zh) * 2018-07-19 2018-11-06 山东省科学院自动化研究所 距离补偿的多输入多输出阵列毫米波三维成像装置及方法
CN109358372A (zh) * 2018-03-09 2019-02-19 同方威视技术股份有限公司 毫米波收发天线阵列、毫米波扫描成像系统及其成像方法
CN109444968A (zh) * 2018-12-29 2019-03-08 清华大学 安检设备及其控制方法
CN109799538A (zh) * 2018-12-29 2019-05-24 清华大学 安检设备及其控制方法
CN109828241A (zh) * 2018-12-29 2019-05-31 清华大学 用于主动式微波毫米波安检设备的电磁成像装置
CN209342935U (zh) * 2018-12-29 2019-09-03 清华大学 安检设备

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990007130A1 (en) * 1988-12-19 1990-06-28 Millitech Corporation Millimiter-wave imaging system, particularly for contraband detection
US5557283A (en) * 1991-08-30 1996-09-17 Sheen; David M. Real-time wideband holographic surveillance system
US6965340B1 (en) * 2004-11-24 2005-11-15 Agilent Technologies, Inc. System and method for security inspection using microwave imaging
US7548185B2 (en) * 2005-09-30 2009-06-16 Battelle Memorial Institute Interlaced linear array sampling technique for electromagnetic wave imaging
US7844081B2 (en) * 2006-05-15 2010-11-30 Battelle Memorial Institute Imaging systems and methods for obtaining and using biometric information
US9615765B2 (en) * 2012-09-04 2017-04-11 Vayyar Imaging Ltd. Wideband radar with heterogeneous antenna arrays
US9715012B2 (en) * 2013-04-25 2017-07-25 Battelle Memorial Institute Footwear scanning systems and methods
CN104375144A (zh) * 2013-08-15 2015-02-25 同方威视技术股份有限公司 毫米波三维全息扫描成像设备及人体或物品检查方法
CN105607056A (zh) * 2015-12-28 2016-05-25 深圳市太赫兹科技创新研究院 人体安检系统和方法
CN105759315B (zh) * 2016-04-26 2018-10-23 华讯方舟科技有限公司 扫描机构及具有该扫描机构的安检仪
CN106054181B (zh) * 2016-05-18 2018-07-20 中国电子科技集团公司第四十一研究所 一种用于太赫兹实时成像的一维稀疏阵列布置方法
CN206209132U (zh) * 2016-08-25 2017-05-31 同方威视技术股份有限公司 面向非合作人体安检的主动式毫米波成像系统
CN106546981A (zh) * 2016-10-24 2017-03-29 复旦大学 运动人体安检成像系统和方法
CN106556873B (zh) * 2016-10-31 2018-08-31 华讯方舟科技有限公司 一种基于人体微波成像的安检方法及系统
CN107102325B (zh) * 2017-05-05 2019-11-15 中国人民解放军国防科学技术大学 一种太赫兹频段旋转阵列扫描成像系统
CN207937600U (zh) * 2018-01-23 2018-10-02 成都菲斯洛克电子技术有限公司 一种主动毫米波成像安全检测系统
CN209821372U (zh) * 2018-12-29 2019-12-20 清华大学 用于主动式微波毫米波安检设备的电磁成像装置和安检设备

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007054685A2 (en) * 2005-11-09 2007-05-18 Qinetiq Limited Passive detection apparatus
CN103616667A (zh) * 2013-11-20 2014-03-05 中国电子科技集团公司第四十一研究所 一种用于散射成像的二维天线阵列布置方法
CN104808201A (zh) * 2015-04-23 2015-07-29 中国电子科技集团公司第四十一研究所 一种二维mimo阵列实现方法
CN206209131U (zh) * 2016-07-26 2017-05-31 华讯方舟科技有限公司 基于毫米波成像的便携式安检设备
CN106093898A (zh) * 2016-08-23 2016-11-09 中国电子科技集团公司第四十研究所 一种分区域式的mimo阵列校准方法
CN109358372A (zh) * 2018-03-09 2019-02-19 同方威视技术股份有限公司 毫米波收发天线阵列、毫米波扫描成像系统及其成像方法
CN108761452A (zh) * 2018-07-19 2018-11-06 山东省科学院自动化研究所 距离补偿的多输入多输出阵列毫米波三维成像装置及方法
CN109444968A (zh) * 2018-12-29 2019-03-08 清华大学 安检设备及其控制方法
CN109799538A (zh) * 2018-12-29 2019-05-24 清华大学 安检设备及其控制方法
CN109828241A (zh) * 2018-12-29 2019-05-31 清华大学 用于主动式微波毫米波安检设备的电磁成像装置
CN209342935U (zh) * 2018-12-29 2019-09-03 清华大学 安检设备

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113156433A (zh) * 2021-05-07 2021-07-23 南京邮电大学 一种微波成像装置
CN113156433B (zh) * 2021-05-07 2023-08-15 南京邮电大学 一种微波成像装置

Also Published As

Publication number Publication date
CN109828241A (zh) 2019-05-31
US12339352B2 (en) 2025-06-24
US20220221576A1 (en) 2022-07-14
CN109828241B (zh) 2024-01-26

Similar Documents

Publication Publication Date Title
CN109828241B (zh) 用于主动式微波毫米波安检设备的电磁成像装置
US11280898B2 (en) Radar-based baggage and parcel inspection systems
US12007523B2 (en) Security inspection apparatus and method of controlling the same
US12164023B2 (en) Security inspection apparatus and method of controlling the same
Moulder et al. Development of a high-throughput microwave imaging system for concealed weapons detection
Sakamoto et al. Ultra-wideband radar imaging using a hybrid of Kirchhoff migration and Stolt FK migration with an inverse boundary scattering transform
WO2017107284A1 (zh) 基于毫米波全息三维成像的人体安检系统及方法
CN209821372U (zh) 用于主动式微波毫米波安检设备的电磁成像装置和安检设备
WO2017107283A1 (zh) 基于线性调频的多人人体安检设备及方法
CN113126175B (zh) 用于主动式毫米波安检成像的多发多收天线阵列布置、人体安检设备和方法
CN209342935U (zh) 安检设备
CN105866771A (zh) 一种隐藏物检测系统及其检测方法
WO2020023603A1 (en) Radar-based baggage and parcel inspection systems
Gonzalez-Valdes et al. On-the-move active millimeter wave interrogation system using a hallway of multiple transmitters and receivers
CN210534345U (zh) 安检设备
CN116224328B (zh) 用于目标多角度扫描的毫米波边缘成像系统及其成像方法
CN109799537A (zh) 安检设备及其控制方法
Sheen et al. Efficient image reconstruction method for a millimeter-wave shoe scanner
Moll et al. Time-difference-of-arrival imaging for ultra-wideband microwave mammography
Prechtel et al. Short-range MIMO radar system considerations
CN112505639A (zh) 一种毫米波收发装置、安检系统
CN114460659B (zh) 安检设备
Li et al. MIMO Radar Near-Field 3-D Imaging Algorithm in Frequency Domain
CN211123307U (zh) 安检设备
CN116500605A (zh) 用于毫米波收发的阵列面板、安检设备及其控制方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19902358

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19902358

Country of ref document: EP

Kind code of ref document: A1

WWG Wipo information: grant in national office

Ref document number: 17309915

Country of ref document: US