Current calculation method, system, NV color center current transformer and storage medium

Abstract

The present application relates to the field of solid-state spin sensing technology, and a kind of current calculation method and system based on NV color center sensing, NV color center current transformer and storage medium;The present application converts the resonance frequency extraction problem of multi-peak ODMR curve into a multi-parameter nonlinear optimization problem, and uses single-peak fitting method to obtain the initial parameters of overall curve fitting, and finally obtains the optimized fitting parameters through Gaussian fitting and iterative optimization, and then obtains more accurate resonance frequency value.

Description

Technical Field

[0001] This invention relates to the field of solid-state spin sensing technology, specifically to a current calculation method, system, NV color center current transformer, and storage medium based on NV color center sensing. Background Technology

[0002] In existing technologies, most diamond NV center (NVC) sensing systems operate based on the photodetector magnetic resonance (PDMR) method. Sensing data allows for the plotting of an ODMR curve with multiple peaks (the vertical axis represents the feedback fluorescence intensity, and the horizontal axis represents the microwave frequency). It is known that during diamond NV center sensing, the magnitude of the external magnetic field is positively correlated with the resonant frequency of the peak on the ODMR curve (i.e., the horizontal axis value of the peak point). Therefore, subsequent sensing calculations can be performed by obtaining the resonant frequency of the peak on the ODMR curve. Currently, the detection of current within a current-carrying conductor is generally achieved by measuring the magnetic field generated by the conductor and then calculating the current magnitude. Based on this, research on applying diamond NV center sensing systems to current detection is gradually increasing.

[0003] Currently, the process of extracting the resonance frequency of the upper peak of the ODMR curve generally involves first fitting the initial nonlinear ODMR curve as a whole, and then obtaining the resonance frequency based on the fitted curve. However, in existing technologies, the initial parameters for the iterative fitting of the curve as a whole are generally obtained manually. The accuracy of the initial parameters obtained by this method is difficult to control, the fitting effect is poor, and it is easy to fail to converge. In addition, the method of manually obtaining parameters and substituting them into the fitting formula is slow, which affects the fitting efficiency. Summary of the Invention

[0004] The purpose of this invention is to propose a current calculation method, system, NV color center current transformer, and storage medium based on NV color center sensing, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A current calculation method based on NV color center sensing, applied to NV color center current transformers based on optically detected magnetic resonance, the method comprising: Plot the detection curve: Plot the initial ODMR curve based on the detection data obtained by the NV color core current transformer detecting the external magnetic field generated by the current-carrying conductor; Obtain initial parameters: Perform single-peak fitting on each peak on the initial ODMR curve, and obtain initial parameters based on the fitting results. The initial parameters include peak intensity information, position information, and full width at half maximum (FWHM) information. Parameter Iterative Optimization: Input the fitting formula into the LM algorithm, and perform iterative optimization using the initial parameters and the horizontal and vertical coordinates on the initial ODMR curve to obtain the optimized parameters. The fitting formula is as follows: ; in, It is a natural constant. Indicates the first The intensity information of each peak, Indicates the first Location information of each peak Indicates the first The half-width information of each peak, Indicates background signal, This represents the total number of peaks on the initial ODMR curve; Extracting resonance frequencies: Extract the position information of the required peaks from the optimized parameters and record them as resonance frequencies; Current calculation: The magnitude of the magnetic field generated by the current-carrying conductor is calculated using the resonant frequency, and then the magnitude of the current in the current-carrying conductor is calculated.

[0006] Furthermore, obtaining the initial parameters also includes the following steps: Step 1: Use a horizontal line to divide the initial ODMR curve so that each peak is divided into parts, forming local peaks with the same number as the total number of peaks. Step 2: Fit each local peak and obtain the initial parameters of each local peak based on the fitting formula.

[0007] Furthermore, in step two, Gaussian fitting is performed on each local peak, and the logarithm of both sides is taken to transform it into polynomial fitting. The Gaussian polynomial for each local peak is then obtained. The Gaussian fitting model is as follows: ; in, It is a natural constant. This indicates the intensity information of the peak. This indicates the location information of the peak. This indicates the full width at half maximum (FWHM) information of the peak. Extract the initial parameters based on the obtained Gaussian polynomial.

[0008] Furthermore, in step one, the process of selecting the horizontal line includes the following steps: S1. Select any value within the range of the ordinate of the initial ODMR curve, and use that value as the initial height to draw a horizontal line. S2. Count the total number of intersections between the horizontal line and the initial ODMR curve, and determine whether the total number of intersections is equal to twice the total number of peaks on the initial ODMR curve. If yes, the horizontal line selection process ends; if not, proceed to the next step. S3. Automatically adjust the height and position of the horizontal line until the total number of intersection points is equal to twice the total number of peaks on the initial ODMR curve, and the horizontal line selection process ends.

[0009] Furthermore, in S3, the height of the horizontal line is automatically adjusted by stepping, and when the total number of intersections is zero, the stepping direction is adjusted in the opposite direction.

[0010] Furthermore, the average value of the set of vertical coordinates on the initial ODMR curve is used as the initial height of the horizontal line.

[0011] Furthermore, the initial height of the horizontal line is determined by the upper or lower limit of the value of the vertical coordinate that is far from the peak point within the range of the vertical coordinate values.

[0012] A current calculation system, comprising: The detection curve plotting module is used to plot the initial ODMR curve based on the detection data obtained by the NV color core current transformer detecting the external magnetic field generated by the current-carrying conductor. The initial parameter acquisition module is used to perform single-peak fitting on each peak on the initial ODMR curve and obtain initial parameters based on the fitting results. The initial parameters include peak intensity information, position information, and full width at half maximum (FWHM) information. Parameter Iteration Optimization Module: This module takes the fitting formula as input into the LM algorithm and uses the initial parameters and the horizontal and vertical coordinates of the initial ODMR curve to perform iterative optimization to obtain the optimized parameters. The fitting formula is as follows: ; in, It is a natural constant. Indicates the first The intensity information of each peak, Indicates the first Location information of each peak Indicates the first The half-width information of each peak, Indicates background signal, This represents the total number of peaks on the initial ODMR curve; The resonance frequency extraction module is used to extract the position information of the required peak from the optimized parameters, which is denoted as the resonance frequency. The current calculation module is used to calculate the magnitude of the magnetic field generated by the current-carrying conductor using the resonant frequency, and then calculate the magnitude of the current in the current-carrying conductor.

[0013] An NV color core current transformer, comprising: One cycle; The diamond NV color center is installed inside the primary ring to sense the magnetic field generated by a current-carrying conductor passing through the hole in the primary ring, and to generate a feedback signal under the stimulation of excitation light. A microwave unit for outputting microwave signals that radiate the diamond NV color center; The laser unit is used to output excitation light; A fluorescence acquisition unit, used to acquire feedback signals; The data processing unit is used to process the feedback signal and perform current calculation using the steps of the current calculation method described above.

[0014] A storage medium storing a computer program, which, when executed by a processor, implements the steps of the current calculation method as described above.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the present application transforms the problem of extracting the resonance frequency of a multi-peak ODMR curve into a multi-parameter nonlinear optimization problem, and uses a single-peak fitting method to obtain the initial parameters for overall curve fitting, and finally obtains the optimized fitting parameters through Gaussian fitting and iterative optimization, thereby obtaining a more accurate resonance frequency value. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of the current calculation method in an embodiment of the present invention; Figure 2 This is the initial ODMR curve with eight peaks in this embodiment of the invention; Figure 3 This is a schematic diagram of cutting the initial ODMR curve using a horizontal line in an embodiment of the present invention; Figure 4 This is a schematic diagram of local peak fitting in an embodiment of the present invention; Figure 5 This is another schematic diagram of local peak fitting in an embodiment of the present invention; Figure 6 This is a flowchart of the horizontal line selection process in an embodiment of the present invention; Figure 7 This is a schematic diagram of the current calculation system in an embodiment of the present invention; Figure 8 This is a schematic diagram of the NV color core current transformer in an embodiment of the present invention; Figure 9 This is a schematic diagram of the connection between the diamond NV color center and the optical fiber in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0020] In the description of this application, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0021] Example of Current Calculation Method

[0022] As a basic implementation example, as shown in the appendix Figure 1 As shown, this paper introduces a current calculation method based on NV color center sensing. This method is applied to NV color center current transformers based on optically detected magnetic resonance, and includes the following steps: S10. Plot the detection curve: Plot the initial ODMR curve based on the detection data obtained by the NV color core current transformer to detect the external magnetic field generated by the current-carrying conductor. For example, in one feasible solution, magnetic field sensing is performed using an NV color center current transformer and optically detected magnetic resonance method to obtain the following... Figure 2 The initial ODMR curve shown has 8 peaks (the magnetic field must be projected onto all four axes of the NV color center to form an initial ODMR curve with 8 peaks). S11. Obtain initial parameters: Perform single-peak fitting on each peak of the initial ODMR curve, and obtain initial parameters based on the fitting results. The initial parameters include peak intensity information, position information, and full width at half maximum (FWHM) information. For example, as a feasible solution, the least squares method can be used to fit nonlinear data. Specifically, the fitting region for each peak is set, and the initial parameters of each peak are obtained by manually selecting them. Taking the initial ODMR curve of 8 peaks as an example, the intensity information (referring to the ordinate value of the peak point), the position information (referring to the abscissa value of the peak point), and the half-width at half-maximum information of each peak are manually selected. Of course, in addition to selecting the initial parameters, there are other techniques that can also be used to obtain the initial parameters, such as camera recognition technology. S12. Parameter Iterative Optimization: Input the fitting formula into the LM algorithm, and use the initial parameters and the horizontal and vertical coordinates on the initial ODMR curve for iterative optimization to obtain the optimized parameters. The fitting formula is as follows: ; in, It is a natural constant. Indicates the first The intensity information of each peak, Indicates the first Location information of each peak Indicates the first The half-width information of each peak, Indicates background signal, This represents the total number of peaks on the initial ODMR curve; For example, in one feasible approach, taking an initial ODMR curve with 8 peaks as an example, the parameters... =8, The value is set to 0 based on the fact that no fluorescence output is 0; S13. Extracting the resonance frequency: Extract the position information of the required peak from the optimized parameters and record it as the resonance frequency; It is known that the peak spacing of the paired peaks with respect to the center frequency on the ODMR curve is related to the magnitude of the magnetic field. Therefore, the magnitude of the external magnetic field can be quantitatively solved by the resonant frequency difference of the paired peaks. The position information of a pair of peaks can be selected for calculation according to actual needs.

[0023] S14. Current Calculation: The magnitude of the magnetic field generated by the current-carrying conductor is calculated using the resonant frequency, and then the magnitude of the current in the current-carrying conductor is calculated.

[0024] It is known that the magnetic field at a fixed position outside a current-carrying conductor can be determined using the resonant frequency, and the magnitude of the current inside the conductor can be determined using Biot-Savart's law without considering external magnetic field interference.

[0025] In the basic embodiment, fitting a single peak requires manually defining the fitting region sequentially, which is inefficient. Therefore, an improved scheme is proposed here, which specifically includes: Step 1: Use a horizontal line to divide the initial ODMR curve so that each peak is divided into parts, forming local peaks with the same number as the total number of peaks. To illustrate, a horizontal line is used to quickly segment all peaks. Under the algorithm's influence, the local fitting region for each peak can be rapidly determined. An example of this approach is shown in the diagram illustrating the segmentation of the initial ODMR curves for the eight peaks. Figure 3 As shown; Step 2: Fit each local peak and obtain the initial parameters of each local peak based on the fitting formula.

[0026] For example, the least squares method can be used to fit a single peak (a preliminary fit can be achieved without parameters). In this example, as a preferred option, the Solve operator encapsulated in OpenCV is used to achieve single peak fitting.

[0027] As a further improvement, in step two above, Gaussian fitting is performed on each local peak, and the logarithm of both sides is taken to transform it into polynomial fitting. The Gaussian polynomial for each local peak is then obtained. The Gaussian fitting model is as follows: ; in, It is a natural constant. This indicates the intensity information of the peak. This indicates the location information of the peak. This indicates the full width at half maximum (FWHM) information of the peak. Extract the initial parameters based on the obtained Gaussian polynomial.

[0028] For example, the fitting of the initial ODMR curve after segmentation for 8 peaks, and the solution obtained using the Solve operator in OpenCV, are shown in the attached figure. Figure 4 and attached Figure 5 As shown in the figure (Note: The smooth curve in the figure is the fitted curve).

[0029] Regarding the selection of the horizontal line in step one above, a specific solution is introduced here, as shown in the appendix. Figure 6 As shown, the solution includes the following steps: S1. Select any value within the range of the ordinate of the initial ODMR curve, and use that value as the initial height to draw a horizontal line. S2. Count the total number of intersections between the horizontal line and the initial ODMR curve, and determine whether the total number of intersections is equal to twice the total number of peaks on the initial ODMR curve. If yes, the horizontal line selection process ends; if not, proceed to the next step. For example, taking an 8-peak ODMR curve as an example, it requires that the horizontal line and the curve have exactly 16 intersection points before the cutting process can be completed. S3. Automatically adjust the height and position of the horizontal line until the total number of intersections is equal to twice the total number of peaks on the initial ODMR curve, and the horizontal line selection process ends. As a preferred setting, in S3, the height position of the horizontal line is automatically adjusted by a stepping method, and when the total number of intersections is equal to zero, the stepping direction is adjusted in the opposite direction. For example, a specific method is to replace the horizontal line by multiplying its height by 1.01 until the intersection number requirement is met.

[0030] As a preferred method, the average value of the set of ordinates on the initial ODMR curve is used as the initial height of the horizontal line. Experiments have shown that this value can basically satisfy the cutting of all peaks, and if it cannot, the cutting of all peaks can be achieved quickly through step adjustment.

[0031] As another preferred option, considering that the larger the proportion of the local peak to the entire single-peak area, the more accurate the fitting effect, the more accurate the fitting effect, the local peaks should be made to have a larger proportion as much as possible. Based on this consideration, the following setting is made here: the upper or lower limit value of the vertical coordinate range farthest from the peak point is taken as the initial height of the horizontal line. For example, the attached... Figure 3 For example, its peak is on the lower side. In order to obtain a local peak with a larger area, the initial height of the horizontal line should be set to the upper limit of the range of values ​​of the curve's vertical coordinate.

[0032] Example of a current calculation system

[0033] Corresponding to the above method embodiments, this application also provides a current calculation system, and the current calculation system described below can be referred to in correspondence with the current calculation method described above.

[0034] See appendix Figure 7 The system includes the following modules: The detection curve plotting module 200 is used to plot the initial ODMR curve based on the detection data obtained by the NV color core current transformer detecting the external magnetic field generated by the current-carrying conductor. The initial parameter acquisition module 210 is used to perform single-peak fitting on each peak on the initial ODMR curve and obtain initial parameters based on the fitting results. The initial parameters include peak intensity information, position information, and full width at half maximum (FWHM) information. The parameter iterative optimization modulus 220 is used to input the fitting formula into the LM algorithm and perform iterative optimization using the initial parameters and the horizontal and vertical coordinates on the initial ODMR curve to obtain the optimized parameters. The fitting formula is as follows: ; in, It is a natural constant. Indicates the first The intensity information of each peak, Indicates the first Location information of each peak Indicates the first The half-width information of each peak, Indicates background signal, This represents the total number of peaks on the initial ODMR curve; The resonance frequency extraction module 230 is used to extract the position information of the required peak from the optimized parameters, and denoted as the resonance frequency. The current calculation module 240 is used to calculate the magnitude of the magnetic field generated by the current-carrying conductor using the resonant frequency, and then calculate the magnitude of the current in the current-carrying conductor.

[0035] By applying the current calculation system provided in this example, single-peak fitting of each peak of the ODMR curve can be achieved, thereby quickly and accurately extracting the initial fitting parameters of each peak. This improves the overall fitting speed and quality of the ODMR curve, leading to more accurate calculation results in subsequent calculations.

[0036] As a preferred embodiment, the system also includes a local peak cutting and fitting module. The function of this module includes: using a horizontal line to divide the initial ODMR curve so that each peak is divided into parts, forming local peaks with the same number as the total number of peaks. For each local peak, a fitting is performed, and the initial parameters of each local peak are obtained based on the fitting formula. In an exemplary scheme, a Gaussian fitting is performed on each local peak, and the logarithm of both sides is taken to transform it into a polynomial fitting. The Gaussian polynomial of each local peak is then solved, where the Gaussian fitting model is: ; in, It is a natural constant. This indicates the intensity information of the peak. This indicates the location information of the peak. This indicates the full width at half maximum (FWHM) information of the peak. Extract the initial parameters based on the obtained Gaussian polynomial.

[0037] As another preferred embodiment, the system further includes a horizontal line selection module, which has the following functions: First, select any value within the range of the ordinate of the initial ODMR curve, and use that value as the initial height to draw a horizontal line. Next, count the total number of intersections between the horizontal line and the initial ODMR curve, and determine whether the total number of intersections is equal to twice the total number of peaks on the initial ODMR curve. If yes, the horizontal line selection process ends; otherwise, proceed to the next step. The horizontal line height is then automatically adjusted until the total number of intersections equals twice the total number of peaks on the initial ODMR curve, at which point the horizontal line selection process ends.

[0038] Preferably, the system also includes a step adjustment module, which automatically adjusts the height position of the horizontal line by stepping, and adjusts the stepping direction in the opposite direction when the total number of intersections is zero.

[0039] Preferably, the system also includes an initial height setting module, through which the initial height of the horizontal line can be set. For example, in some schemes, the average value of the set of ordinates on the initial ODMR curve is set as the initial height of the horizontal line; in other schemes, the upper or lower limit value of the ordinate value range that is far from the peak point can also be set as the initial height of the horizontal line.

[0040] NV color core current transformer example

[0041] Corresponding to the above current calculation method embodiment, this embodiment also provides an NV color core current transformer, as shown in the attached figure. Figure 8 As shown, it includes: One cycle 1; The diamond NV color center 2 is installed inside the primary ring 1 to sense the magnetic field generated by the current-carrying conductor 7 passing through the inner hole of the primary ring 1, and to generate a feedback signal under the stimulation of excitation light. Microwave unit 3, which is used to output microwave signals that radiate the diamond NV color center 2; Laser unit 4 is used to output excitation light; Fluorescence acquisition unit 5, which is used to acquire feedback signals; The data processing unit 6 is used to process the feedback signal and perform current calculation using the steps of the current calculation method described above.

[0042] In the exemplary solution, as shown in the appendix Figure 8 As shown, a primary ring 1 has a total of 4 diamond NV color centers 2 evenly distributed. A microwave antenna is set near each diamond NV color center 2. The microwave signal is ultimately radiated to the diamond NV color center 2 through the microwave antenna. The excitation light and the feedback signal (red fluorescence) are transmitted through different optical fibers (exemplary structural design as shown). Figure 9 (As shown).

[0043] Storage Media Examples

[0044] Corresponding to the above embodiments of the current calculation method, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the current calculation method as described above.

[0045] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0046] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0047] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0048] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A current calculation method based on NV color center sensing, applied to NV color center current transformers based on optically detected magnetic resonance, characterized in that, The method includes: Plot the detection curve: Plot the initial ODMR curve based on the detection data obtained by the NV color core current transformer detecting the external magnetic field generated by the current-carrying conductor; Obtain initial parameters: Perform single-peak fitting on each peak on the initial ODMR curve, and obtain initial parameters based on the fitting results. The initial parameters include peak intensity information, position information, and full width at half maximum (FWHM) information. Parameter Iterative Optimization: Input the fitting formula into the LM algorithm, and perform iterative optimization using the initial parameters and the horizontal and vertical coordinates on the initial ODMR curve to obtain the optimized parameters. The fitting formula is as follows: ； in, It is a natural constant. Indicates the first The intensity information of each peak, Indicates the first Location information of each peak Indicates the first The half-width information of each peak, Indicates background signal, This represents the total number of peaks on the initial ODMR curve; Extracting resonance frequencies: Extract the position information of the required peaks from the optimized parameters and record them as resonance frequencies; Current calculation: The magnitude of the magnetic field generated by the current-carrying conductor is calculated using the resonant frequency, and then the magnitude of the current in the current-carrying conductor is calculated.

2. The current calculation method as described in claim 1, characterized in that, Obtaining the initial parameters also includes the following steps: Step 1: Use a horizontal line to divide the initial ODMR curve so that each peak is divided into parts, forming local peaks with the same number as the total number of peaks. Step 2: Fit each local peak and obtain the initial parameters of each local peak based on the fitting formula.

3. The current calculation method as described in claim 2, characterized in that, In step two, Gaussian fitting is performed on each local peak, and the logarithm of both sides is taken to transform it into polynomial fitting. The Gaussian polynomial for each local peak is then obtained. The Gaussian fitting model is as follows: ； in, It is a natural constant. This indicates the intensity information of the peak. This indicates the location information of the peak. This indicates the full width at half maximum (FWHM) information of the peak. Extract the initial parameters based on the obtained Gaussian polynomial.

4. The current calculation method as described in claim 2 or 3, characterized in that, Step one, the process of selecting the horizontal line, includes the following steps: S1. Select any value within the range of the ordinate of the initial ODMR curve, and use that value as the initial height to draw a horizontal line. S2. Count the total number of intersections between the horizontal line and the initial ODMR curve, and determine whether the total number of intersections is equal to twice the total number of peaks on the initial ODMR curve. If yes, the horizontal line selection process ends; if not, proceed to the next step. S3. Automatically adjust the height and position of the horizontal line until the total number of intersection points is equal to twice the total number of peaks on the initial ODMR curve, and the horizontal line selection process ends.

5. The current calculation method as described in claim 4, characterized in that, In S3, the height of the horizontal line is automatically adjusted by stepping, and the stepping direction is reversed when the total number of intersections is zero.

6. The current calculation method as described in claim 4, characterized in that, The average value of the set of ordinates on the initial ODMR curve is used as the initial height of the horizontal line.

7. The current calculation method as described in claim 4, characterized in that, The initial height of the horizontal line is determined by the upper or lower limit of the value of the vertical coordinate that is far from the peak point within the range of the vertical coordinate.

8. A current calculation system, characterized in that, Include: The detection curve plotting module is used to plot the initial ODMR curve based on the detection data obtained by the NV color core current transformer detecting the external magnetic field generated by the current-carrying conductor. The initial parameter acquisition module is used to perform single-peak fitting on each peak on the initial ODMR curve and obtain initial parameters based on the fitting results. The initial parameters include peak intensity information, position information, and full width at half maximum (FWHM) information. The parameter iteration optimization module is used to input the fitting formula into the LM algorithm and perform iterative optimization using the initial parameters and the horizontal and vertical coordinates on the initial ODMR curve to obtain the optimized parameters. The fitting formula is: ； in, It is a natural constant. Indicates the first The intensity information of each peak, Indicates the first Location information of each peak Indicates the first The half-width information of each peak, Indicates background signal, This represents the total number of peaks on the initial ODMR curve; The resonance frequency extraction module is used to extract the position information of the required peak from the optimized parameters, which is denoted as the resonance frequency. The current calculation module is used to calculate the magnitude of the magnetic field generated by the current-carrying conductor using the resonant frequency, and then calculate the magnitude of the current in the current-carrying conductor.

9. An NV color core current transformer, characterized in that, Include: One cycle; The diamond NV color center is installed inside the primary ring to sense the magnetic field generated by a current-carrying conductor passing through the hole in the primary ring, and to generate a feedback signal under the stimulation of excitation light. A microwave unit for outputting microwave signals that radiate the diamond NV color center; The laser unit is used to output excitation light; A fluorescence acquisition unit, used to acquire feedback signals; A data processing unit is used to process the feedback signal and perform current calculation using the steps of the current calculation method as described in claims 1-7.

10. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the current calculation method as described in any one of claims 1-7.

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