Human body security check three-dimensional imaging rapid implementation method considering rotation and translation compensation

Abstract

The invention relates to a human body security check three-dimensional imaging rapid implementation method considering rotation and translation compensation, and the method comprises the steps: switching different antenna channels through a switch in the height direction, and carrying out the electronic scanning of a target; real-time spatial position information of the target is acquired in the azimuth direction, and motion information of the target is determined according to the real-time spatial position information; transmitting the chirp signal to a target, and receiving an echo signal reflected by the target based on the transmitted chirp signal; performing height-direction processing on the echo signal so as to perform synthetic aperture imaging focusing in the height direction, and generating data after height-direction focusing; performing three-dimensional focusing on the azimuth to generate azimuth focused data; and parallel computing is carried out on the height-direction focused data, the azimuth-direction focused data and the horizontal-direction amplitude motion compensation imaging data so as to generate a final human body security check three-dimensional imaging result. Therefore, the problems of rapid motion compensation real-time imaging and the like of transmission passing type and natural walking type security check systems are solved.

Description

Technical Field

[0001] The present application relates to the field of security inspection technology, and in particular to a method for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotational and translational compensation. Background Art

[0002] With the rapid development of transportation technologies such as airplanes, high-speed rail, and subways, my country's public transportation volume has skyrocketed, creating a demand for faster and contactless human security checks. Taking Beijing as an example, airports, high-speed rail, and subway hubs primarily rely on manual metal detection for security checks. Inspectors rely on feel to identify the person's belongings, which is time-consuming, has a high false alarm rate, low detection efficiency, and a low level of user-friendliness.

[0003] Microwave radar, leveraging its varying reflection intensities from different materials, can be used for human security inspections, penetrating clothing and detecting hidden objects. Active microwave security inspection systems actively transmit modulated electromagnetic wave signals, which reflect off the target and generate echoes. Using the SAR (Synthetic Aperture Radar) imaging principle, they create a three-dimensional security image. Active microwave security inspection systems primarily utilize linear or planar array antennas. Linear array antennas are lower cost than planar array antennas and offer broader application prospects.

[0004] Mainstream linear array systems use a stationary scanning method where the linear array mechanically moves to scan, requiring personnel to maintain a certain posture and reducing security inspection throughput. Using a stationary linear array system where the person is teleported or walking through the system theoretically achieves the same effect, reducing stationary and preparation time and speeding up inspections.

[0005] The relevant technology adopts the above-mentioned method of human body transmission, and uses a depth camera to obtain the motion information of the target subject, and adopts a three-dimensional BP (Back Projection) algorithm to achieve a certain degree of motion compensation imaging; or adopts a working method in which the human body does not move and the linear array scans in a circular motion, and adopts an ω-k frequency domain imaging algorithm in the height direction and a back projection algorithm based on circular motion in the horizontal direction to achieve three-dimensional imaging; or adopts an ω-k frequency domain imaging algorithm in the height direction and a BP algorithm in the horizontal direction. The BP algorithm can naturally achieve motion compensation in the horizontal and depth directions. In addition, horizontal motion compensation based on amplitude correction is also proposed.

[0006] However, in the related art, the advantage of the area array system is fast scanning and imaging, but the disadvantage is high cost. The advantage of the linear array mechanical scanning system with a stationary human body is reduced system cost, but the disadvantage is that the personnel stay longer, which reduces the security inspection speed. The linear array system with human body transmission maintains the advantages of low cost and high security inspection throughput. The disadvantage is that it is more difficult for the human body to remain still when being transmitted than when standing still on the ground. Therefore, a depth camera is used to obtain motion information. However, the three-dimensional BP imaging algorithm used is a time-domain imaging algorithm, which is computationally intensive and time-consuming, and cannot meet the requirements of real-time imaging. The imaging algorithm uses the frequency domain ω-k imaging algorithm along the linear array direction and the BP algorithm in the horizontal direction, which reduces the computational complexity and speeds up the imaging speed. However, this algorithm is only applicable to circular SAR with a stationary target and is not applicable to human body transmission-through systems that consider human motion compensation. The method applicable to human body transmission-through systems does not consider motion compensation in the height direction and three-dimensional rotational motion, and is not applicable to systems where the human body naturally walks through, and urgently needs to be improved. Summary of the Invention

[0007] The present application provides a method for rapidly implementing three-dimensional imaging of human body security inspections taking into account rotational and translational compensation, so as to solve the problems of rapid motion compensation and real-time imaging in conveyor-type and natural walking security inspection systems.

[0008] The first aspect of the present application provides a method for quickly implementing three-dimensional imaging for human body security inspection taking into account rotational and translational compensation, including the following steps: using a switch to switch different antenna channels to perform electronic scanning of the target in the altitude direction to generate scanning data that meets the target's high-resolution conditions; based on the scanning data that meets the target's high-resolution conditions, obtaining the target's real-time spatial position information in the azimuth direction to determine the target's motion information based on the real-time spatial position information; based on the motion information, transmitting a linear frequency modulation signal to the target, and receiving an echo signal reflected by the target based on the transmitted linear frequency modulation signal; performing altitude processing on the echo signal to perform synthetic aperture imaging focusing on the altitude direction to generate altitude-focused data; performing three-dimensional focusing on the azimuth direction to generate azimuth-focused data; and parallelly calculating the altitude-focused data, the azimuth-focused data, and the amplitude motion compensated imaging data in the horizontal direction to generate a final three-dimensional imaging implementation result for human body security inspection.

[0009] Optionally, in one embodiment of the present application, the acquiring of the real-time spatial position information of the target in the azimuth direction to determine the motion information of the target based on the real-time spatial position information includes: acquiring the transformation matrix from the target coordinate system of the target to the antenna coordinate system using a depth camera; and determining the motion information including a three-dimensional rotation matrix and a three-dimensional translation vector based on the transformation matrix.

[0010] Optionally, in one embodiment of the present application, before the parallel calculation of the height-focused data, the azimuth-focused data and the horizontal amplitude motion-compensated imaging data, it also includes: sorting the target azimuth position of the depth camera to determine the sorted position and index relationship; reordering the echo signal, the three-dimensional rotation matrix and the three-dimensional translation vector according to the sorted position and the index relationship to generate a reordered result; based on the reordered result, calculating the amplitude weight coefficient of each sampling position; and weighting the echo signal according to the amplitude weight coefficient to generate the horizontal amplitude motion-compensated imaging data.

[0011] Optionally, in one embodiment of the present application, the calculation formula of the horizontal amplitude motion compensation imaging data is:

[0012]

[0013] Among them, F is the imaging result of the echo signal s(x′,n,t) through the height-range two-dimensional range migration algorithm, (x i ,y i ,z i ) represents the coordinates of the imaging grid points, n new Represents the index after reordering the horizontal sampling positions, A(n new ) represents the amplitude weighting coefficient after reordering.

[0014] Optionally, in one embodiment of the present application, the calculation formula of the linear frequency modulation signal is:

[0015]

[0016] Where t is the depth time, τ is the pulse width, f0 is the carrier frequency, K r is the frequency modulation slope.

[0017] Optionally, in one embodiment of the present application, the calculation formula of the echo signal is:

[0018]

[0019] Among them, σ(x i ,y i ,z i ) is the radar cross section of the i-th target point, is the distance from the antenna to the target.

[0020] According to a second aspect of the present application, an embodiment provides a device for rapidly implementing three-dimensional imaging for human body security inspection taking into account rotational and translational compensation, comprising: a scanning module for electronically scanning a target in an altitude direction by switching different antenna channels using a switch to generate scanning data that meets the target's high-resolution condition; an acquisition module for acquiring real-time spatial position information of the target in an azimuth direction based on the scanning data that meets the target's high-resolution condition, so as to determine the target's motion information based on the real-time spatial position information; a transmitting module for transmitting a linear frequency modulation signal to the target based on the motion information, and receiving an echo signal reflected by the target based on the transmitted linear frequency modulation signal; a processing module for performing altitude processing on the echo signal to perform synthetic aperture imaging focusing on the altitude direction to generate data focused in the altitude direction; a generation module for performing three-dimensional focusing on the azimuth direction to generate data focused in the azimuth direction; and an implementation module for parallelly calculating the focused data in the altitude direction, the focused data in the azimuth direction, and the amplitude motion compensated imaging data in the horizontal direction to generate a final three-dimensional imaging implementation result for human body security inspection.

[0021] Optionally, in one embodiment of the present application, the acquisition module includes: an acquisition unit for acquiring the transformation matrix from the target coordinate system of the target to the antenna coordinate system using a depth camera; and a determination unit for determining the motion information including a three-dimensional rotation matrix and a three-dimensional translation vector based on the transformation matrix.

[0022] Optionally, in one embodiment of the present application, it also includes: a sorting module for sorting the target azimuth position of the depth camera before parallel calculation of the height-focused data, the azimuth-focused data and the horizontal amplitude motion-compensated imaging data to determine the sorted position and index relationship; a reordering module for reordering the echo signal, the three-dimensional rotation matrix and the three-dimensional translation vector according to the sorted position and the index relationship to generate a reordering result; a calculation module for calculating the amplitude weight coefficient of each sampling position based on the reordering result; a weighted processing module for weighting the echo signal according to the amplitude weight coefficient to generate the horizontal amplitude motion-compensated imaging data.

[0023] Optionally, in one embodiment of the present application, the calculation formula of the horizontal amplitude motion compensation imaging data is:

[0024]

[0025] Among them, F is the imaging result of the echo signal s(x′,n,t) through the height-range two-dimensional range migration algorithm, (x i ,y i ,zi ) represents the coordinates of the imaging grid points, n new Represents the index after reordering the horizontal sampling positions, A(n new ) represents the amplitude weighting coefficient after reordering.

[0026] Optionally, in one embodiment of the present application, the calculation formula of the linear frequency modulation signal is:

[0027]

[0028] Where t is the depth time, τ is the pulse width, f0 is the carrier frequency, K r is the frequency modulation slope.

[0029] Optionally, in one embodiment of the present application, the calculation formula of the echo signal is:

[0030]

[0031] Among them, σ(x i ,y i ,z i ) is the radar cross section of the i-th target point, is the distance from the antenna to the target.

[0032] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement a method for rapidly implementing three-dimensional imaging of human body security inspections that takes into account rotational and translational compensation as described in the above embodiments.

[0033] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the above-mentioned method for rapid implementation of three-dimensional imaging of human body security inspection considering rotation and translation compensation.

[0034] The fifth aspect of the present application provides a computer program product, which stores a computer program. When the program is executed by a processor, it implements the above-mentioned method for rapid implementation of three-dimensional imaging of human body security inspection considering rotation and translation compensation.

[0035] The present embodiment considers the effects of the target's three-dimensional rotation and translation and integrates them into the ωk-BP imaging algorithm. This not only achieves target motion-compensated imaging but also improves computational speed (compared to the three-dimensional BP algorithm). It is suitable for human pass-through or human walking security inspection systems. This solves the problem of fast motion-compensated real-time imaging in pass-through and natural walking security inspection systems.

[0036] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0038] Figure 1 This is a flowchart of a method for rapidly implementing three-dimensional imaging for human body security inspection taking into account rotational and translational compensation according to an embodiment of the present application;

[0039] Figure 2 Schematic diagram of a security inspection system according to one embodiment of the present application;

[0040] Figure 3 This is a diagram of three-point imaging results according to one embodiment of the present application;

[0041] Figure 4 is a graph showing changes in azimuth position over time according to one embodiment of the present application;

[0042] Figure 5 Target motion trajectory (left) x direction (center) y direction (right) z direction diagram according to one embodiment of the present application;

[0043] Figure 6 Graphs of a three-point imaging simulation according to one embodiment of the present application (left), the original ωk-BP algorithm (center), the method without amplitude correction (right), and the method with amplitude correction;

[0044] Figure 7 This is a schematic structural diagram of a device for rapidly implementing three-dimensional imaging of human body security inspections taking into account rotational and translational compensation according to an embodiment of the present application;

[0045] Figure 8 A schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0047] The following describes, with reference to the accompanying drawings, a method for rapidly implementing three-dimensional human body security inspection imaging that takes into account rotational and translational compensation, according to an embodiment of the present application. In response to the problems of rapid motion-compensated real-time imaging for transport-through and natural walking security inspection systems mentioned in the background art above, the present application provides a method for rapidly implementing three-dimensional human body security inspection imaging that takes into account rotational and translational compensation. This method considers the motion effects of the target's three-dimensional rotation and translational motion and integrates them into the ωk-BP imaging algorithm, achieving both target motion-compensated imaging and improved computational speed. The method is suitable for transport-through or human walking security inspection systems. This solves the problems of rapid motion-compensated real-time imaging for transport-through and natural walking security inspection systems.

[0048] Specifically, Figure 1 A flowchart of a method for rapidly implementing three-dimensional imaging of human body security inspections taking into account rotational and translational compensation provided in an embodiment of the present application.

[0049] like Figure 1 As shown, the method for rapidly implementing three-dimensional imaging of human body security inspection considering rotation and translation compensation includes the following steps:

[0050] In step S101 , a switch is used to switch different antenna channels in an altitude direction to perform electronic scanning of a target, so as to generate scanning data that meets a high-resolution condition of the target.

[0051] In the actual implementation process, Figure 2 As shown, the embodiment of the present application can realize electronic scanning in the height direction by switching different antenna channels, usually at an extremely fast speed of about 2m / s, and generate high-resolution scanning data.

[0052] In step S102 , based on the scanning data that meets the target high-resolution condition, real-time spatial position information of the target is acquired in the azimuth direction, so as to determine the motion information of the target according to the real-time spatial position information.

[0053] In actual implementation, the embodiments of the present application can use the natural human motion in azimuth, based on high-resolution scan data, at a speed of approximately 0.5 m / s. Therefore, it can be roughly assumed that the target is stationary during electronic scanning in height, i.e., in a "walk-stop-walk" mode. Human motion can be roughly decomposed into the rotational and translational motions of multiple rigid bodies, such as the upper and lower arms, main torso, and thighs, to obtain the target's real-time spatial position information, and then determine the target's motion information based on the real-time spatial position information.

[0054] Optionally, in one embodiment of the present application, real-time spatial position information of the target is obtained in the azimuth direction to determine the motion information of the target based on the real-time spatial position information, including: using a depth camera to obtain the transformation matrix of the target coordinate system to the antenna coordinate system; determining the motion information including a three-dimensional rotation matrix and a three-dimensional translation vector based on the transformation matrix.

[0055] Among them, the embodiment of the present application can use the depth camera to obtain the transformation matrix of the target coordinate system to the antenna coordinate system, and determine the motion information including the three-dimensional rotation matrix and the three-dimensional translation vector based on the transformation matrix.

[0056] In step S103 , based on the motion information, a chirp signal is transmitted to the target, and an echo signal reflected by the target based on the transmitted chirp signal is received.

[0057] In actual implementation, the embodiment of the present application may transmit a linear frequency modulation signal to a target for reflection based on motion information, and receive an echo signal reflected by the target based on the transmitted linear frequency modulation signal.

[0058] In one embodiment of the present application, the calculation formula of the linear frequency modulation signal is:

[0059]

[0060] Where t is the depth time, τ is the pulse width, f0 is the carrier frequency, K r is the frequency modulation slope.

[0061]

[0062] In the algorithm derivation, the rectangular envelope w(t) does not affect the focusing effect. In the following, its influence will be ignored in the signal, and the focus will be on phase processing.

[0063] In step S104 , the echo signal is processed in the altitude direction to perform synthetic aperture imaging focusing in the altitude direction to generate altitude-focused data.

[0064] Specifically, the embodiment of the present application can perform altitude processing on the echo signal to perform synthetic aperture imaging focusing in the altitude direction to generate altitude-focused data.

[0065] The embodiment of the present application may consider height processing, fix n, that is, for each vertical slice, use the ω-k algorithm to achieve synthetic aperture imaging focusing in the height direction.

[0066] The coordinates of the antenna in the antenna coordinate system are (x′,0,0), and the coordinates of the target in the target coordinate system are (x i ,y i ,z i), the depth camera can obtain the transformation matrix from the target coordinate system to the antenna coordinate system, which is divided into three-dimensional rotation matrix and the three-dimensional translation vector The acquisition method can be through deep learning skeleton point recognition or point cloud recognition. The coordinates of the target in the antenna coordinate system can be expressed as:

[0067]

[0068] The transmitted signal is reflected by the target and received by the radar receiver, and then de-linear frequency modulation is performed on it together with the original transmitted signal.

[0069] In one embodiment of the present application, the calculation formula of the echo signal is:

[0070]

[0071] Among them, σ(x i ,y i ,z i ) is the radar cross section of the i-th target point, is the distance from the antenna to the target. It can be seen that the obtained echo signal is a three-dimensional matrix. The first dimension represents the sampling information of different positions along the height axis, and the second dimension represents the time information of the target moving to different positions along the y-axis.

[0072] In step S105 , three-dimensional focusing is performed on the azimuth direction to generate azimuthally focused data.

[0073] In the actual implementation process, the embodiment of the present application can perform three-dimensional focusing on the azimuth to generate azimuth focused data. The embodiment of the present application can consider azimuth processing, according to the position information (x i (n),y i (n),z i (n)), BP algorithm is used to complete three-dimensional focusing, a motion compensation method for three-dimensional rotation and three-dimensional translation is proposed, and the ωk-BP algorithm is integrated to achieve the focusing imaging effect, and the imaging speed is greatly improved.

[0074] In step S106 , the height-focused data, the azimuth-focused data, and the horizontal amplitude motion-compensated imaging data are calculated in parallel to generate a final human body security inspection three-dimensional imaging result.

[0075] It is understood that each decomposed rigid body motion module of the human body in the embodiments of this application has the same 3D motion information, and by imaging different modules separately, it is ultimately possible to achieve security inspection of all torso parts. This application focuses on algorithm research and only performs imaging analysis on the 3D translational and rotational motion of a rigid body, which is equivalent to imaging analysis of a single module of the human body.

[0076] Among them, the embodiment of the present application can parallelly calculate the data after focusing in the height direction, the data after focusing in the azimuth direction, and the amplitude motion compensation imaging data in the horizontal direction to generate the final three-dimensional imaging result of human body security inspection, and use the GPU platform for parallel computing to further achieve the goal of accelerated imaging.

[0077] This application considers the effects of three-dimensional rotation and translation of the target and integrates them into the ωk-BP imaging algorithm. This not only achieves target motion-compensated imaging but also improves computational speed (compared to the three-dimensional BP algorithm). It is suitable for human body transmission and human body movement inspection systems.

[0078] Let f = K r t, then the echo signal is rewritten as:

[0079]

[0080] Wave number Then the target signal can be reconstructed as:

[0081]

[0082] in, represents the position of point i at time n. Based on the spherical wave hypothesis and stationary point phase theory, we have:

[0083]

[0084] k x is the wave number corresponding to the x′ direction.

[0085] Substituting (2) into (1), we have:

[0086]

[0087] The above formula completes the Fourier transform of x′. By interpolation, the new wave number k yz is the uniform wave number axis, k rc represents the starting wave number. Then formula (3) can be expressed as:

[0088]

[0089] Where F is S(k x ,n,k yz ) About k x ,k yz The two-dimensional inverse Fourier transform of . Combining the above steps, equation (4) can be summarized as:

[0090]

[0091] Thus completing the point (x i ,y i ,z i ) Three-dimensional focused imaging, traversing all points The imaging of the entire scene can be completed. It should be noted that in the above formula, the integral terms of the three dimensions of F are all functions of n. For different points (x i ,y i ,z i ), the integral term in F is also different. It reflects the three-dimensional rotation matrix and the three-dimensional translation vector The algorithm is an ideal imaging algorithm when the Stolt accuracy is very high.

[0092] In practical applications, due to sampling reasons, equation (5) needs to be discretized. It can be expressed as:

[0093]

[0094] The uneven sampling of the horizontal synthetic aperture caused by target motion will lead to an increase in the horizontal sidelobes and reduce the imaging quality. Figure 3 As shown in Figure 1, the blue trajectory represents uniform motion in azimuth over time, and the red trajectory represents non-uniform motion. This non-uniform sampling effect will lead to an increase in the target sidelobes, resulting in blurred imaging images.

[0095] Optionally, in one embodiment of the present application, before the parallel calculation of the height-focused data, the azimuth-focused data and the horizontal amplitude motion-compensated imaging data, it also includes: sorting the target azimuth position of the depth camera to determine the sorted position and index relationship; reordering the echo signal, the three-dimensional rotation matrix and the three-dimensional translation vector according to the sorted position and index relationship to generate a reordered result; based on the reordered result, calculating the amplitude weight coefficient of each sampling position; and weighting the echo signal according to the amplitude weight coefficient to generate horizontal amplitude motion-compensated imaging data.

[0096] In the actual implementation process, the solution proposed in the embodiment of the present application is the azimuth sampling amplitude weighting algorithm. The idea is to place the sampling position along Reordering, that is, reordering the sampling positions horizontally, reducing the weight of signals with denser sampling and increasing the weight of signals with sparser sampling. The implementation method is as follows:

[0097] 1) Sort the target azimuth positions obtained by the depth camera from small to large: After getting the sort and index relation n new .

[0098] 2) s(x′,n,k) is converted into new Rearrange the new position of s(x′,n new ,k)=s(x′,n,k)[n new ], and also for the three-dimensional rotation matrix and the three-dimensional translation vector Reordering completed.

[0099] 3) Calculation The amplitude weight coefficient of , using the derivative (diff) and average (mean) functions:

[0100] 4) Approximately replaced by A(n new ), wherein, in one embodiment of the present application, the calculation formula of the horizontal amplitude motion compensation imaging data is:

[0101]

[0102] Among them, F is the imaging result of the echo signal s(x′,n,t) through the height-range two-dimensional range migration algorithm, (x i ,y i ,z i ) represents the coordinates of the imaging grid points, n new Represents the index after reordering the horizontal sampling positions, A(n new ) represents the reordered amplitude weighting coefficient, which is used to achieve horizontal motion compensation effect.

[0103] The calculation result obtained by formula (7) is recorded as the final three-dimensional imaging result. Both the ω-k algorithm part and the BP algorithm part of this method can be accelerated by GPU parallel computing.

[0104] Specifically, it can be combined Figures 4 to 6 As shown, the working principle of the method for rapidly implementing three-dimensional imaging of human body security inspection considering rotation and translation compensation in the embodiment of the present application is described in detail with a specific embodiment.

[0105] This application can give simulation results:

[0106] First, we tested the imaging speed. The transmitted signal frequency was 13-18 GHz, the number of sampling points in altitude, azimuth, and range were 180, 198, and 400, respectively. The number of spatial grid points was uniformly divided into 180*101*41. The calculation times for the 3D BP algorithm, this method (CPU calculation), and this method (GPU calculation) were 1110.43s, 58.86s, and 0.56s, respectively. The imaging effect of the target in uniform motion is shown in the figure below. Figure 4As shown in the figure, the three methods have the same imaging effect, but the GPU-accelerated method can achieve near real-time calculation, which can improve the security inspection throughput.

[0107] Given the target center trajectory as Figure 5 As shown in the curve, the three-dimensional translation vector changes with time. Figure 6 The imaging effects of the three methods are shown. The left figure is the original ωk-BP algorithm. This method does not consider the movement in the height direction and does not have the amplitude compensation considered in formula (7). The imaging is completely defocused. The middle figure is the present method, but does not consider A(n new ), that is, take A(n new )=1, it can be seen that the height direction can be focused, but there is a defocusing problem in the horizontal direction. The right figure shows this method and considers A(n new ), a better focusing effect can be achieved, which verifies the effectiveness and feasibility of this method.

[0108] The rapid implementation of 3D human body security inspection imaging with rotational and translational compensation, proposed in the embodiments of this application, takes into account the effects of the target's 3D rotational and translational motion and integrates them into the ωk-BP imaging algorithm. This not only achieves target motion-compensated imaging but also improves computational speed. This method is suitable for human body transport-through or human body movement-through security inspection systems. This solves the problem of rapid motion-compensated real-time imaging in transport-through and natural walking security inspection systems.

[0109] Next, a device for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotational and translational compensation proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0110] Figure 7 It is a structural diagram of a device for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotation and translation compensation according to an embodiment of the present application.

[0111] like Figure 7 As shown, the device 10 for rapidly implementing three-dimensional imaging for human body security inspection considering rotation and translation compensation includes: a scanning module 100 , an acquisition module 200 , a transmitting module 300 , a processing module 400 , a generating module 500 and an implementing module 600 .

[0112] Specifically, the scanning module 100 is used to electronically scan the target by switching different antenna channels in the vertical direction using a switch, so as to generate scanning data that meets the target high-resolution condition.

[0113] The acquisition module 200 is configured to acquire the real-time spatial position information of the target in the azimuth direction based on the scanning data that meets the target high-resolution condition, so as to determine the motion information of the target according to the real-time spatial position information.

[0114] The transmitting module 300 is configured to transmit a linear frequency modulation signal to a target based on motion information, and receive an echo signal reflected by the target based on the transmitted linear frequency modulation signal.

[0115] The processing module 400 is used to perform altitude processing on the echo signal to perform synthetic aperture imaging focusing in the altitude direction and generate altitude-focused data.

[0116] The generating module 500 is used to perform three-dimensional focusing on the azimuth direction to generate azimuthally focused data.

[0117] The implementation module 600 is used to parallelly calculate the height-focused data, the azimuth-focused data, and the horizontal amplitude motion-compensated imaging data to generate the final human body security inspection three-dimensional imaging implementation result.

[0118] Optionally, in one embodiment of the present application, the acquisition module 200 includes: an acquisition unit and a determination unit.

[0119] The acquisition unit is used to use the depth camera to acquire the conversion matrix from the target coordinate system to the antenna coordinate system of the target.

[0120] The determining unit is used to determine motion information including a three-dimensional rotation matrix and a three-dimensional translation vector according to the transformation matrix.

[0121] Optionally, in one embodiment of the present application, the apparatus 10 for rapidly implementing three-dimensional imaging of human body security inspection considering rotation and translation compensation further includes: a sorting module, a re-sorting module, a calculation module, and a weighted processing module.

[0122] Among them, the sorting module is used to sort the target azimuth position of the depth camera before parallel calculation of the height focused data, the azimuth focused data and the horizontal amplitude motion compensated imaging data to determine the sorted position and index relationship.

[0123] The reordering module is used to reorder the echo signal, the three-dimensional rotation matrix and the three-dimensional translation vector according to the sorted position and index relationship to generate a reordering result.

[0124] The calculation module is used to calculate the amplitude weight coefficient of each sampling position based on the reordering result.

[0125] The weighted processing module is used to perform weighted processing on the echo signal according to the amplitude weight coefficient to generate horizontal amplitude motion compensated imaging data.

[0126] Optionally, in one embodiment of the present application, the calculation formula for the horizontal amplitude motion compensation imaging data is:

[0127]

[0128] Among them, F is the imaging result of the echo signal s(x′,n,t) through the height-range two-dimensional range migration algorithm, (x i ,y i ,z i ) represents the coordinates of the imaging grid points, n new Represents the index after reordering the horizontal sampling positions, A(n new ) represents the amplitude weighting coefficient after reordering.

[0129] Optionally, in one embodiment of the present application, the calculation formula of the linear frequency modulation signal is:

[0130]

[0131] Where t is the depth time, τ is the pulse width, f0 is the carrier frequency, K r is the frequency modulation slope.

[0132] Optionally, in one embodiment of the present application, the calculation formula of the echo signal is:

[0133]

[0134] Among them, σ(x i ,y i ,z i ) is the radar cross section of the i-th target point, is the distance from the antenna to the target.

[0135] It should be noted that the above explanation of the embodiment of the method for quickly implementing three-dimensional imaging of human body security inspection considering rotation and translation compensation is also applicable to the device for quickly implementing three-dimensional imaging of human body security inspection considering rotation and translation compensation of this embodiment, and will not be repeated here.

[0136] The apparatus for rapidly implementing three-dimensional human body security inspection imaging with rotational and translational compensation, proposed in an embodiment of the present application, takes into account the effects of the target's three-dimensional rotational and translational motion and integrates these effects into the ωk-BP imaging algorithm. This not only achieves target motion-compensated imaging but also improves computational speed. This apparatus is suitable for human body transport-through or human body movement-through security inspection systems. This solves the problem of rapid motion-compensated real-time imaging for transport-through and natural walking security inspection systems.

[0137] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0138] A memory 801 , a processor 802 , and a computer program stored in the memory 801 and executable on the processor 802 .

[0139] When the processor 802 executes the program, the method for rapidly implementing three-dimensional imaging for human body security inspection taking into account rotation and translation compensation provided in the above embodiment is implemented.

[0140] Furthermore, the electronic device further includes:

[0141] The communication interface 803 is used for communication between the memory 801 and the processor 802 .

[0142] The memory 801 is used to store computer programs that can be run on the processor 802.

[0143] The memory 801 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0144] If the memory 801, processor 802, and communication interface 803 are implemented independently, the communication interface 803, memory 801, and processor 802 can be connected to each other via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0145] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

[0146] The processor 802 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0147] This embodiment also provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotation and translation compensation is implemented as described above.

[0148] An embodiment of the present application also provides a computer program product on which a computer program is stored. When the program is executed by a processor, the method for quickly implementing three-dimensional imaging of human body security inspection taking into account rotation and translation compensation is implemented as described above.

[0149] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0150] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0151] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing a custom logical function or process step, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

[0152] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or N wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program can be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing it in other suitable ways as necessary, and then storing it in a computer memory.

[0153] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0154] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0155] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0156] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for rapidly implementing three-dimensional imaging of human body security inspection considering rotation and translation compensation, characterized in that: The following steps are involved: At high altitude, the switch is used to switch different antenna channels to perform electronic scanning of the target to generate scanning data that meets the target's high-resolution conditions; Based on the scanning data that meets the target high-resolution condition, acquiring real-time spatial position information of the target in azimuth, so as to determine motion information of the target according to the real-time spatial position information; Based on the motion information, transmitting a linear frequency modulation signal to the target, and receiving an echo signal reflected by the target based on the transmitted linear frequency modulation signal; Performing altitude processing on the echo signal to perform synthetic aperture imaging focusing on the altitude direction to generate altitude-focused data; performing three-dimensional focusing on the azimuth direction to generate azimuthally focused data; The height-focused data, the azimuth-focused data, and the horizontal amplitude motion-compensated imaging data are calculated in parallel to generate a final human body security inspection three-dimensional imaging result.

2. The method according to claim 1, characterized in that Acquiring the real-time spatial position information of the target in the azimuth direction to determine the motion information of the target according to the real-time spatial position information includes: Obtaining a conversion matrix from a target coordinate system of the target to an antenna coordinate system using a depth camera; The motion information including a three-dimensional rotation matrix and a three-dimensional translation vector is determined according to the transformation matrix.

3. The method according to claim 2, characterized in that Before the parallel calculation of the height-focused data, the azimuth-focused data, and the horizontal amplitude motion-compensated imaging data, the method further includes: Sorting the target azimuth positions of the depth cameras to determine sorted positions and index relationships; Reordering the echo signal, the three-dimensional rotation matrix, and the three-dimensional translation vector according to the sorted positions and the index relationship to generate a reordering result; Calculating an amplitude weight coefficient for each sampling position based on the reordering result; The echo signal is weighted according to the amplitude weight coefficient to generate the amplitude motion compensated imaging data in the horizontal direction.

4. The method according to claim 1, wherein The calculation formula for the horizontal amplitude motion compensation imaging data is: Among them, F is the imaging result of the echo signal s(x′,n,t) through the height-range two-dimensional range migration algorithm, (x i ,y i ,z i ) represents the coordinates of the imaging grid points, n new Represents the index after reordering the horizontal sampling positions, A(n new ) represents the amplitude weighting coefficient after reordering.

5. The method according to claim 1, wherein The calculation formula of the linear frequency modulation signal is: Where t is the depth time, τ is the pulse width, f0 is the carrier frequency, K r is the frequency modulation slope.

6. The method according to claim 1, characterized in that The calculation formula of the echo signal is: Among them, σ(x i ,y i ,z i ) is the radar cross section of the i-th target point, is the distance from the antenna to the target.

7. A device for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotation and translation compensation, characterized in that: include: A scanning module is used to electronically scan the target by switching different antenna channels at a high altitude to generate scanning data that meets the target's high-resolution requirements; an acquisition module, configured to acquire real-time spatial position information of the target in an azimuth direction based on the scanning data that meets the target high-resolution condition, so as to determine motion information of the target according to the real-time spatial position information; a transmitting module, configured to transmit a linear frequency modulation signal to the target based on the motion information, and receive an echo signal reflected by the target based on the transmitted linear frequency modulation signal; a processing module, configured to perform altitude processing on the echo signal to perform synthetic aperture imaging focusing on the altitude and generate altitude-focused data; A generating module, configured to perform three-dimensional focusing on the azimuth direction to generate azimuthally focused data; The implementation module is used to parallelly calculate the height-focused data, the azimuth-focused data and the horizontal amplitude motion-compensated imaging data to generate the final human body security inspection three-dimensional imaging implementation result.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a method for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotational and translational compensation as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the method for rapidly implementing three-dimensional imaging of human body security inspection taking into account rotation and translation compensation as described in any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that The computer program is executed to implement the method for rapidly implementing three-dimensional imaging for human body security inspection taking into account rotation and translation compensation as described in any one of claims 1 to 6.

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