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CN-122021285-A - Long Bo lens reverse engineering method based on electromagnetic backscattering

CN122021285ACN 122021285 ACN122021285 ACN 122021285ACN-122021285-A

Abstract

The invention discloses a Long Bo lens reverse engineering method based on electromagnetic backscattering, which relates to the technical field of detection imaging of Long Bo lenses and comprises the following steps: s1, collecting data: arranging an electromagnetic wave transmitter and a receiver outside the lens, acquiring electromagnetic information of the lens through transmitting and receiving, and S2, discretizing: the method comprises the steps of obtaining lens scattering field data through excitation and receiving of electromagnetic waves with multiple angles and multiple frequencies, modeling the continuous dielectric constant distribution in the lens by means of the implicit neural network, and obtaining three-dimensional structure information of the lens more freely and accurately.

Inventors

  • WANG JIAKUI
  • LIU YALAN
  • YANG YUE

Assignees

  • 湖北查克科技有限责任公司

Dates

Publication Date
20260512
Application Date
20260123

Claims (6)

  1. 1. A Long Bo lens reverse engineering method based on electromagnetic backscattering is characterized by comprising the following steps: s1, collecting data, namely arranging an electromagnetic wave transmitter and an electromagnetic wave receiver outside a lens, and acquiring electromagnetic information of the lens through transmitting and receiving; S2, discretizing, namely dividing a target area into a plurality of grids, and calculating and accumulating to obtain a predicted scattered field; S3, constructing a mapping network from a space point to an induced current, constructing a mapping network from the induced current to a dielectric constant, and combining training; S4, network model testing, namely inputting a spatial position vector into a dielectric constant prediction network and outputting a dielectric constant value of a corresponding position; In the step S1, an electromagnetic wave transmitter and a receiver are adopted, both the space position and the direction of the electromagnetic wave transmitter and the direction of the electromagnetic wave receiver are accurately controlled by a mechanical arm, the mechanical arm moves outside an imaging area according to a preset track, the transmitter radiates electromagnetic waves to a lens under the conditions of different space orientations and different incidence angles, and meanwhile, the other group of mechanical arms carry the receiver to be arranged at each observation angle position outside the lens and receive scattered echo signals, so that the coverage of the full circumferential scattering information of the lens is realized.
  2. 2. The method for reverse engineering Long Bo lenses based on electromagnetic backscatter as claimed in claim 1, wherein in S1, two measurement processes are performed under the control of a mechanical arm to obtain high-precision scattered field data, and the method comprises the following steps: firstly, under the condition that a lens is not placed, collecting a background field according to the same mechanical arm track; Then, placing the lens in the area, and enabling the mechanical arm to repeat the same measuring path to obtain a total field containing a lens effect, and extracting pure scattered field data caused by the lens by subtracting the total field and a background field point by point; Finally, the scattering values obtained by the transmitting-receiving combinations under the control of all the mechanical arms are constructed into a scattering field measurement matrix according to the transmitter number, the receiver number and the frequency index, and the electromagnetic scattering characteristics of the lens under multiple angles and multiple frequency bands are described.
  3. 3. The method of Long Bo lens reverse engineering according to claim 1, wherein in S2, the scene is divided into grids, the induced currents are calculated at discrete points and accumulated to be approximately continuous integral, specifically, the target region ROI is divided into a plurality of small cube grids, a plurality of points are randomly sampled at the center of each grid, the induced currents are calculated at the discrete points, and the predicted scattered field is obtained by accumulated to be approximately continuous integral.
  4. 4. The method for reverse engineering Long Bo lens based on electromagnetic backscatter according to claim 1, wherein in S3, a mapping network from space point to induced current is constructed, namely a first network, approximates the induced current of each point in space, the network takes the coordinates of any three-dimensional space point and the coordinates of a transmitter in a target area as input, and the induced current corresponding to the point is output by training and fitting the interaction relation between electromagnetic waves and a medium; In the training process, the induced currents of all the space points in the whole scene are accumulated to form a complete predicted scattered field, the predicted scattered field is compared with the scattered field actually measured by a receiver, a loss function is calculated, and network parameters are optimized through back propagation, so that the induced currents generated by each space point under the irradiation of different transmitters can be accurately predicted, and the design of the network allows the network to automatically capture multiple scattering phenomena and complex responses of high-contrast media.
  5. 5. The method for reverse engineering Long Bo lens based on electromagnetic backscatter according to claim 4, wherein in S3, a mapping network of induced current to dielectric constant is constructed, namely a second network, the induced current is mapped to dielectric constant of corresponding space point, the network takes three-dimensional coordinates of each space point as input, and the dielectric constant of the point is output, so that dielectric distribution of any space point is directly obtained; In the training process, the network calculates a predicted induced current by using a dielectric constant predicted by the network itself, and performs loss calculation by taking the induced current output by the first network as a reference, optimizing network parameters through back propagation, and predicting the dielectric constant of any space by a nonlinear mapping relation between the second network and the induced current; the first network and the second network are trained in a combined mode, the first network generates induced current distribution, the second network maps the induced current distribution into dielectric constants, two network parameters are optimized simultaneously through counter propagation, the three-dimensional structure inside the lens is reconstructed with high precision, and continuous dielectric constant distribution is predicted.
  6. 6. The method for reverse engineering Long Bo lens system based on electromagnetic backscatter according to claim 5, wherein in S4, after model training is completed, three-dimensional space coordinates in the region are input as continuous query points to a trained dielectric constant prediction network, the network is a differentiable implicit field representation model, and the input is a spatial position vector and the output is a dielectric constant value of a corresponding position; in the actual reconstruction process, a series of discrete coordinate-dielectric constant pairs are obtained by performing traversal sampling on continuous coordinates in a region according to a set spatial resolution, and the data points form a three-dimensional point cloud representation of the dielectric constant inside the target.

Description

Long Bo lens reverse engineering method based on electromagnetic backscattering Technical Field The invention relates to the technical field of detection imaging of Long Bo lenses, in particular to a Long Bo lens reverse engineering method based on electromagnetic backscattering. Background The lens has extremely high application prospect in a plurality of fields such as optical imaging, communication antennas, space optics and the like due to the unique omnidirectional focusing characteristic, low aberration and wide band applicability, the optical element has extremely high requirement on the three-dimensional continuous distribution of the refractive index inside the material, and in the traditional nondestructive testing technology,Radiographic imaging is a widely used means,The physical mechanism of interaction of the rays and the material only relates to attenuation and absorption of the rays, the imaging information essentially reflects the macroscopic mass distribution characteristics of the material, the electromagnetic characteristics of the material cannot be directly revealed, and the problem of electromagnetic wave back-scattering imaging needs to be solved for reconstruction of the internal structure of the scattererIn order to ensure the numerical stability, the continuous space must be discretized into voxels or grids, and the space discretization inevitably brings resolution loss, so that the continuous change of the dielectric constant is forced to be represented by discrete points; Existing technology Photoimaging does not provide the true refractive index change law and optical working mechanism when studying the internal structure of the graded index optical element,Under the scene of larger refractive index gradient or complex material internal structure, multiple scattering can be obviously enhanced, inversion difficulty is further increased, the traditional linearization method or weak scattering approximation is difficult to be applicable, the reverse scattering imaging method and coarse discretization can destroy the natural spherical symmetry or radial symmetry structure of Long Bo lenses, so that the estimated refractive index curve is dithered or discontinuous, and theoretical model fitting and manufacturing quality verification are affected; To avoid the above-mentioned problems, it is necessary to provide a Long Bo lens reverse engineering method based on electromagnetic backscatter to overcome the drawbacks of the prior art. Disclosure of Invention The invention provides a Long Bo lens reverse engineering method based on electromagnetic backscattering, which can effectively solve the problem that the prior art is proposed in the prior artPhotoimaging does not provide the true refractive index change law and optical working mechanism when studying the internal structure of the graded index optical element,Under the scene that the refractive index gradient is large or the internal structure of the material is complex, multiple scattering can be obviously enhanced, inversion difficulty is further increased, the traditional linearization method or weak scattering approximation is difficult to be applicable, the reverse scattering imaging method and coarse discretization can destroy the natural spherical symmetry or radial symmetry structure of the Long Bo lens, and the estimated refractive index curve is dithered or discontinuous, so that the fitting of a theoretical model and the verification of manufacturing quality are influenced. In order to achieve the purpose, the invention provides a Long Bo lens reverse engineering method based on electromagnetic backscattering, which comprises the following steps: s1, collecting data, namely arranging an electromagnetic wave transmitter and an electromagnetic wave receiver outside a lens, and acquiring electromagnetic information of the lens through transmitting and receiving; S2, discretizing, namely dividing a target area into a plurality of grids, and calculating and accumulating to obtain a predicted scattered field; S3, constructing a mapping network from a space point to an induced current, constructing a mapping network from the induced current to a dielectric constant, and combining training; S4, network model testing, namely inputting a spatial position vector into a dielectric constant prediction network and outputting a dielectric constant value of a corresponding position; In the step S1, an electromagnetic wave transmitter and a receiver are adopted, both the space position and the direction of the electromagnetic wave transmitter and the direction of the electromagnetic wave receiver are accurately controlled by a mechanical arm, the mechanical arm moves outside an imaging area according to a preset track, the transmitter radiates electromagnetic waves to a lens under the conditions of different space orientations and different incidence angles, and meanwhile, the other group of mechanical arms carry the receiver to be arra