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CN-121142135-B - Magnetic field inversion current method based on near field scanning

CN121142135BCN 121142135 BCN121142135 BCN 121142135BCN-121142135-B

Abstract

The invention discloses a magnetic field inversion current method based on near field scanning, which comprises the steps of acquiring magnetic field data in a circuit and taking the magnetic field data as input, expanding a measurement plane for the magnetic field to obtain a magnetic field matrix The method comprises the steps of enabling current of an original magnetic field matrix H on a boundary to be continuous, constructing a relation between a magnetic field and current in a frequency domain space, reconstructing current distribution by using a Tikhonov regularization method, optimally selecting regularization parameters required by the Tikhonov regularization method by using a GCV method, extracting structural information of a static current model, taking the structural information as a mask, acting the mask on a radio frequency current model result, and outputting current in an original measurement window as current reconstructed by a final method. According to the invention, the current artifact on the boundary is eliminated by expanding the measurement plane, the current distribution is automatically solved by regularization, errors caused by empirical selection of filtering parameters are avoided, the accuracy of the reconstructed current is improved, and finally, the spatial noise is suppressed by a mask method, so that the accurate reconstruction of the radio frequency current is realized.

Inventors

  • ZHOU YANGYANG
  • YIN YUHANG
  • XIAO WEN
  • MA HONGRU

Assignees

  • 汕头大学

Dates

Publication Date
20260505
Application Date
20250928

Claims (5)

  1. 1. A magnetic field inversion current method based on near field scanning, comprising the steps of: S1, acquiring magnetic field data in a circuit and taking the magnetic field data as input; acquisition of two-dimensional field data of horizontal magnetic field components radiated by a circuit by near field scanning , Takes it as input ; S2, for the two-dimensional field data 、 Respectively expanding the measurement planes to obtain a magnetic field matrix , The current of the original magnetic field matrix H on the boundary is continuous; S3, constructing the relation between the magnetic field and the current in the frequency domain space: Of the formula (I) , , , , Respectively represent pairs of , , , , Performing Fourier transformation; S4, reconstructing current distribution by using a Tikhonov regularization method, and optimally selecting regularization parameters required by the Tikhonov regularization method by using a GCV method; S5, extracting structural information of the static current model, taking the structural information as a mask, and acting the structural information on a radio frequency current model result; and S6, outputting the current in the original measurement window as the current reconstructed by the final method.
  2. 2. The method for field inversion current according to claim 1, wherein said step of expanding said magnetic field in S2 comprises expanding an original magnetic field matrix H into a 3*3 magnetic field matrix by using a row-flipped column-flipped expanded magnetic field distribution : Wherein the magnetic field matrix H is obtained by turning over Obtained by turning over the rows Is obtained by turning over the H rows and columns 。
  3. 3. The near field scanning based magnetic field inversion current method according to claim 2, wherein in S3 The values of (2) are: Wherein, when the current is regarded as static current, Expressed as: ; When the current is considered to be a radio frequency current, Expressed as: 。
  4. 4. a magnetic field inversion current method based on near field scanning according to claim 3 wherein the cost function of Tikhonov regularization method used in S4 is expressed as: Of the formula (I) The two norms are represented by the two norms, , Is a solution that minimizes the cost function, The regularization parameters are represented by a set of values, Is a linear operator used to control the smoothness of the solution.
  5. 5. The near field scan based magnetic field inversion current method according to claim 4 wherein said functional discrete form of GCV method in S4 is expressed as: wherein M and N respectively represent magnetic field matrix When the number of rows and columns of In the minimum of the time period, Is the optimal regularization parameter value.

Description

Magnetic field inversion current method based on near field scanning Magnetic field inversion current method based on near field scanning Technical Field The invention relates to the technical field of circuit detection, in particular to a magnetic field inversion current method based on near field scanning. Background In nondestructive testing and electromagnetic compatibility testing of a circuit, the rapid and accurate measurement of the current distribution in the circuit is helpful for rapidly and intuitively determining the position of a fault point, and the testing flow is simplified. Therefore, the realization of nondestructive and noncontact detection of the circuit current is important for electromagnetic compatibility analysis of the circuit. To date, some related efforts have been made in which time domain restoration algorithms can achieve detection of current signals at single point locations, but cannot achieve regional detection of current. The prior art can also use a fourier space reconstruction method to realize the region detection of electrostatic current, such as a flow chart shown in fig. 1, but the method needs to select reconstruction parameters empirically, and the reconstruction current result is easy to be interfered by electromagnetic noise, test height and other factors, and when the method is used for reconstructing radio frequency current, the method generally treats the current as electrostatic current, which can lead to larger inversion current error and inaccurate test, and secondly, the prior fourier space reconstruction method needs to select spatial filtering parameters empirically, the parameters are selected empirically, and current distribution reconstructed by selecting different parameter values has larger difference, and then, when the current distribution exists at the boundary, the current result reconstructed by the prior fourier space reconstruction method has artifacts at the boundary. Therefore, this technique has yet to be addressed for inverting the current distribution based on the radio frequency magnetic field. Disclosure of Invention The technical problem to be solved by the embodiment of the invention is to provide a magnetic field inversion current method based on near field scanning, which can accurately reconstruct radio frequency current. In order to solve the technical problems, the embodiment of the invention provides a magnetic field inversion current method based on near field scanning, which is characterized by comprising the following steps: S1, acquiring magnetic field data in a circuit and taking the magnetic field data as input; acquisition of two-dimensional field data of horizontal magnetic field components radiated by a circuit by near field scanning 、Takes it as input; S2, for the two-dimensional field data、Respectively expanding the measurement planes to obtain a magnetic field matrix,The current of the original magnetic field matrix H on the boundary is continuous; S3, constructing the relation between the magnetic field and the current in the frequency domain space: Of the formula (I) ,,,,Respectively represent pairs of,,,,Performing Fourier transformation; S4, reconstructing current distribution by using a Tikhonov regularization method, and optimally selecting regularization parameters required by the Tikhonov regularization method by using a GCV method; S5, extracting structural information of the static current model, taking the structural information as a mask, and acting the structural information on a radio frequency current model result; and S6, outputting the current in the original measurement window as the current reconstructed by the final method. Further, in S2, expanding the measurement plane by using the row-flipped column-flipped expanded magnetic field distribution to expand the original magnetic field matrix H into a 3*3 magnetic field matrix: Wherein the magnetic field matrix H is obtained by turning overObtained by turning over the rowsIs obtained by turning over the H rows and columns。 Further, in the S3The values of (2) are: Wherein, when the current is regarded as static current, Expressed as: ; When the current is considered to be a radio frequency current, Expressed as: 。 further, the cost function of the Tikhonov regularization method used in S4 is expressed as: Of the formula (I) The two norms are represented by the two norms,,Is a solution that minimizes the cost function,The regularization parameters are represented by a set of values,Is a linear operator used to control the smoothness of the solution. Further, the discrete form of the function of the GCV method in S4 is expressed as: wherein M and N respectively represent magnetic field matrix When the number of rows and columns ofIn the minimum of the time period,Is the optimal regularization parameter value. The embodiment of the invention has the advantages that the current artifact on the boundary is eliminated by expanding the measuring plane, the