Method and system for extracting amplitude of flipping magnetic field of nitrogen-vacancy color center quantum sensor

Abstract

This invention belongs to the field of current measurement and signal processing technology, specifically disclosing a method and system for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor. The method includes: acquiring the raw signal output by the nitrogen-vacancy color center quantum sensor and preprocessing it; detecting the minimum point of the preprocessed signal, setting a minimum interval and amplitude threshold to eliminate false boundaries, and forming a stable half-cycle segment; constructing two sets of complementary sequences based on the half-cycle segment to achieve the retention of the first half-cycle and zeroing of the second half-cycle, and the retention of the second half-cycle and zeroing of the first half-cycle, respectively, within each cycle; performing fundamental frequency phase-locked demodulation on the two sets of complementary sequences to obtain two fundamental amplitude components; fusing the two fundamental amplitude components to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current. This invention effectively eliminates the measurement error caused by the asymmetry of the positive and negative half-cycles of the original current and achieves stable extraction of the fundamental amplitude.

Description

Technical Field

[0001] This invention relates to the field of current measurement and signal processing technology, and in particular to a method and system for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the development of new power systems, higher requirements are placed on the accuracy, stability, and long-term reliability of current measurements. Magnetic array current sensors have attracted widespread attention due to their simple structure, fast response speed, and ability to achieve non-contact measurement. However, while the tunneling magnetoresistive (TMR) sensors commonly used in arrays have high sensitivity, they suffer from large temperature drift and insufficient long-term stability. To address this, existing technologies attempt to combine diamond nitrogen-vacancy center quantum sensors with TMR arrays to form a hybrid current sensor system. Nitrogen-vacancy centers have the advantages of operating at room temperature, good long-term stability, and resistance to temperature drift, and can provide a real-time amplitude reference for TMR, thereby enabling online monitoring and correction of TMR measurement results.

[0004] However, the physical properties of nitrogen-vacancy color centers dictate that they are only sensitive to the magnitude of the magnetic field, and cannot directly distinguish its direction. When the direction of the measured current reverses, the magnetic field signal output by the nitrogen-vacancy color center remains positive, causing the portion of the waveform below the horizontal axis to flip upwards, forming a so-called "flipped waveform." Furthermore, due to the frequent presence of DC bias in actual measurements, the flipped waveform is usually not strictly symmetrical, but rather exhibits distortion and high-order harmonic contamination. This flipping characteristic makes the output waveform of the nitrogen-vacancy color center difficult to use directly for amplitude monitoring; without processing, it will introduce significant errors, thus making accurate calibration and drift compensation of the TMR output impossible.

[0005] The traditional solution is to introduce an external bias magnet to maintain the unipolarity of the nitrogen-vacancy color center output across the entire current range, thus avoiding waveform inversion. However, bias magnets suffer from large temperature coefficients and poor magnetic field stability, which can introduce new sources of error and reduce the long-term reliability of the overall system. Especially in practical power systems, where temperature environments are complex and variable, the bias magnet solution is difficult to meet the requirements for long-term stable measurement. Therefore, there is an urgent need for a signal processing method that does not rely on an external bias magnet to reconstruct and extract the amplitude of the nitrogen-vacancy color center inversion waveform, enabling it to stably reflect the fundamental amplitude of the current. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a method and system for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor. Without adding a bias magnet, the asymmetry and harmonic interference caused by the flipped waveform can be effectively suppressed through signal processing, thereby providing a stable and accurate amplitude reference for the TMR array and enabling online monitoring and error compensation of the hybrid current sensor.

[0007] In some implementations, the following technical solutions are adopted: A method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor includes: The raw signal output by the nitrogen-vacancy color center quantum sensor was acquired and preprocessed. Minimum point detection is performed on the preprocessed signal, and minimum interval and amplitude threshold are set to eliminate false boundaries and form stable half-cycle segments; Two complementary sequences are constructed based on half-cycle segmentation to achieve the following in each cycle: retaining the first half-cycle and setting the second half-cycle to zero, and retaining the second half-cycle and setting the first half-cycle to zero, respectively. Two complementary sequences are demodulated using fundamental frequency phase-locked loop (PLL) to obtain two fundamental amplitude components. The two fundamental amplitude components are then fused to obtain a nitrogen-vacancy fundamental amplitude monitoring value that is proportional to the amplitude of the measured current.

[0008] As a further step, after obtaining the nitrogen-vacancy fundamental amplitude monitoring value, the method further includes: using the nitrogen-vacancy color center fundamental amplitude monitoring value to perform online compensation on the TMR array output.

[0009] As a further option, let's assume the TMR measurement result is... The calibrated current is: ; in, For the calibrated current, and These are the proportionality coefficient and the bias term, respectively.

[0010] As a further solution, a minimum interval and amplitude threshold are set to eliminate false boundaries, specifically: Set minimum interval With amplitude threshold Boundaries that do not meet the following conditions will be removed: ; in, for The signal after time-based preprocessing; and The detected numbers are respectively the first The and the first The moment of the minimum value point; and These are the preset minimum time interval threshold and amplitude threshold, respectively.

[0011] As a further approach, two sets of complementary sequences are constructed based on the semi-circular segmentation, specifically: First complementary sequence: ; First complementary sequence: ; in, and These represent the constructed first complementary sequence signal and the second complementary sequence signal, respectively. This represents the preprocessed nitrogen-vacancy color center magnetic field signal; , , The detected numbers are respectively the first The, the The and the first The moment of the minimum value point.

[0012] As a further approach, fundamental frequency phase-locked demodulation is performed on the two complementary sequences respectively, specifically as follows: Let the reference signal be: ; The specific calculation for fundamental frequency phase-locked demodulation is as follows: ; in, For the fundamental frequency, This represents the number of sampling points; , representing two sets of complementary sequences, and These represent the quadrature reference signals used for phase-locked demodulation; and They represent the first The discrete values ​​of the reference signal corresponding to each sampling point; Indicates the first The complementary sequence in the first group Discrete values ​​of each sampling point; and They represent the first, second, and third parts respectively. The in-phase and quadrature components obtained by demodulating complementary sequences.

[0013] As a further approach, the two fundamental amplitude components are fused to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current, specifically: ; ; in, This represents the amplitude component of the i-th roadbed wave.

[0014] In other embodiments, the following technical solutions are adopted: A system for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor includes: The data acquisition module is configured to acquire and preprocess the raw signal output by the nitrogen-vacancy color center quantum sensor. The data segmentation module is configured to detect minimum points in the preprocessed signal, set minimum intervals and amplitude thresholds to eliminate false boundaries, and form stable half-cycle segments. The complementary sequence construction module is configured to construct two sets of complementary sequences based on half-cycle segments, so as to achieve the retention of the first half-cycle and the zeroing of the second half-cycle and the retention of the second half-cycle and the zeroing of the first half-cycle respectively in each cycle. The amplitude extraction module is configured to perform fundamental frequency phase-locked demodulation on two sets of complementary sequences to obtain two fundamental amplitude components; and to fuse the two fundamental amplitude components to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current.

[0015] In other embodiments, the following technical solutions are adopted: A terminal device includes a processor and a memory, the processor being used to implement instructions; the memory being used to store multiple instructions adapted to be loaded and executed by the processor to extract the amplitude of the flipped magnetic field of the nitrogen-vacancy color center quantum sensor described above.

[0016] In other embodiments, the following technical solutions are adopted: A computer-readable storage medium storing a plurality of instructions adapted for loading and execution by a processor of a terminal device of the above-described method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention does not rely on a bias magnet, thus avoiding new error sources caused by the large temperature coefficient of the magnet; by constructing a complementary sequence to achieve half-cycle zeroing, the waveform with time-domain flipping and aliasing is decomposed into independent half-cycle components, avoiding even-order harmonic interference faced by direct spectrum analysis; by combining fundamental frequency phase-locked demodulation to extract the amplitude of the two half-cycles and then fusing them, the measurement error caused by the asymmetry of the positive and negative half-cycles of the original current (such as DC bias) is effectively eliminated, and the stable extraction of the fundamental amplitude is achieved.

[0018] This invention utilizes amplitude fusion and online compensation mechanisms to correct the drift of the TMR array in real time, significantly improving the long-term stability and measurement accuracy of the hybrid current sensor in complex environments. It has strong engineering application value and promotion significance.

[0019] Other features and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method for extracting the amplitude of the flipped magnetic field of the nitrogen-vacancy color center quantum sensor in an embodiment of the present invention; Figure 2 This is a schematic diagram of an array-type current transformer structure built according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the nitrogen-vacancy color center quantum sensor structure constructed according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a hybrid current measurement system built according to an embodiment of the present invention; Figures 5(a) and (b) are the time-domain curves of the magnetic field output by the nitrogen-vacancy color center quantum sensor without signal processing, and a magnified view of a part of the field, respectively. Figure 6 This is the time-domain curve obtained by directly extracting the fundamental amplitude of the output of the nitrogen-vacancy color center quantum sensor without signal processing in this embodiment of the invention; Figure 7 This is a schematic diagram of half-cycle zeroing of the nitrogen-vacancy color center quantum sensor in an embodiment of the present invention; Figure 8(a) shows two sets of complementary sequence waveforms obtained after half-cycle zeroing of the output signal of the nitrogen-vacancy color center quantum sensor in an embodiment of the present invention. Figure 8(b) is a magnified view of the two complementary sequences in Figure 8(a); Figure 9 This is the result of summing the fundamental wave amplitudes extracted from the two complementary sequences of the nitrogen-vacancy color center quantum sensor in this embodiment of the invention. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] Example 1 Because of the good temperature drift suppression of nitrogen-vacancy color centers, the hybrid current measurement system uses nitrogen-vacancy color centers to monitor the TMR array online. However, the energy level transition process inside the nitrogen-vacancy color center does not have directional information. Without the addition of a bias magnet, the nitrogen-vacancy color center cannot determine the direction of the alternating magnetic field. Therefore, the output waveform flips when the current reverses, and the waveform exhibits asymmetrical characteristics due to the influence of DC bias, making it difficult to directly use it for amplitude monitoring of TMR.

[0024] Based on this, in one or more embodiments, a method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor is disclosed, combined with Figure 1 Specifically, it includes the following processes: S101: Acquire the raw signal output by the nitrogen-vacancy color center quantum sensor and perform preprocessing, including DC removal, amplitude limiting and bandpass filtering, to remove DC bias, suppress outliers and band-limited noise.

[0025] Assume the original signal is: (1) in, The fundamental amplitude, For the fundamental frequency, For phase, DC bias, This represents the noise component. After moving average DC removal, bandpass filtering, and clipping, the preprocessed signal is obtained. : (2) in, This indicates the residual noise component after preprocessing.

[0026] S102: Perform minimum point detection on the preprocessed signal, set minimum interval and amplitude threshold to eliminate false boundaries, and form stable half-cycle segments.

[0027] Since the nitrogen-vacancy color center outputs a flipping magnetic field signal (i.e., magnetic field magnitude), the zero-crossing point of the original measured current appears as a concave trough (minimum) on the signal waveform. Therefore, the detected minimum point is the starting and ending boundary of the half-cycle.

[0028] This embodiment uses the sliding window method. Perform local minimum detection. Set a length of... L A sliding window is used; if the amplitude of the current sampling point is less than the amplitudes of all other points within the window, it is identified as a candidate minimum point (i.e., a trough); the time indices of all candidate points are collected to obtain the initial boundary set. .

[0029] Meanwhile, to ensure robustness, a minimum interval threshold is introduced. and amplitude threshold Boundaries that do not meet the following conditions are considered pseudo-minimums and are eliminated: (3) in, for The signal after time-based preprocessing; and The detected numbers are respectively the first The and the first The moment of the minimum value point; and These are the preset minimum time interval threshold and amplitude threshold, respectively.

[0030] When an abnormal deviation in the time interval between adjacent boundaries is detected, the boundary position can be further corrected to improve the positioning accuracy of the semi-circular segment boundary and enhance the stability of the subsequent complementary sequence construction.

[0031] S103: Construct two sets of complementary sequences based on half-cycle segmentation to achieve "retain the first half-cycle and set the second half-cycle to zero" and "retain the second half-cycle and set the first half-cycle to zero" respectively within each cycle.

[0032] In this embodiment, a complete cycle interval is defined as... Then the first complementary sequence is defined as: (4) The second complementary sequence is: (5) in, and These represent the constructed first complementary sequence signal and the second complementary sequence signal, respectively. This represents the preprocessed nitrogen-vacancy color center magnetic field signal.

[0033] Complementary sequences are formed through segmented gating. The gating window can be a rectangular window, a Hanning window, or a smooth window with overlap, in order to reduce the impact of discontinuities in inter-segment splicing on demodulation.

[0034] The first sequence retains the first half of each cycle and sets the second half to zero, while the second sequence retains the second half of each cycle and sets the first half to zero. The purpose of the above operations is to decouple the time-domain flipped and aliased waveform into independent half-cycle components, so that subsequent phase-locked demodulation can extract the magnetic field amplitudes corresponding to the positive and negative half-cycles of the original current respectively, thereby effectively avoiding the difficulties in direct spectrum analysis and phase ambiguity caused by the flipping effect.

[0035] S104: Perform fundamental frequency phase-locked demodulation on the two complementary sequences to obtain two fundamental amplitude components; fuse the two fundamental amplitude components to obtain the nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current.

[0036] In this embodiment, the fundamental frequency phase-locked demodulation adopts the I / Q demodulation method. The fundamental frequency reference is multiplied by the complementary sequence and integrated or averaged within the effective sampling window to obtain the I and Q components and calculate their amplitudes. The reference signal is assumed to be: (6) I / Q demodulation is calculated as follows: (7) Two fundamental wave amplitude components Specifically: ; in, For the fundamental frequency, This represents the number of sampling points; , representing two sets of complementary sequences, and These represent the quadrature reference signals (cosine and sine) used for phase-locked demodulation, respectively. and They represent the first The discrete values ​​of the reference signal corresponding to each sampling point; Indicates the first The complementary sequence in the first group Discrete values ​​of each sampling point; and They represent the first, second, and third parts respectively. The in-phase and quadrature components obtained by demodulating complementary sequences.

[0037] The fundamental frequency reference is determined based on the half-cycle boundary interval statistics or the nominal power frequency and can be updated adaptively; the demodulation window length is consistent with or proportional to the half-cycle or full-cycle segment length to ensure that the reference phase is aligned with the data segment.

[0038] The two amplitude values ​​are fused to obtain the fundamental amplitude monitoring value of the nitrogen-vacancy color center. : (8) Amplitude fusion can be achieved by summing or averaging the amplitudes of the two channels, or by weighted fusion based on half-cycle energy, signal-to-noise ratio, or demodulation residual; amplitudes of abnormal half-cycles can be fused after median filtering, Hampel filtering, or threshold removal.

[0039] In this embodiment, the fundamental frequency phase-locked demodulation adopts the I / Q demodulation method. The fundamental frequency reference is multiplied by the complementary sequence and integrated or averaged within the effective sampling window to obtain the I and Q components and calculate the amplitude. Then, the components are fused, which effectively eliminates the measurement error caused by the asymmetry of the positive and negative half-cycles of the original current (such as DC bias) and realizes the stable extraction of the fundamental frequency amplitude.

[0040] S105: Online compensation of TMR array output is performed using the nitrogen-vacancy color center fundamental wave amplitude monitoring value.

[0041] Let the TMR measurement result be The calibrated current is: (10) in, For the calibrated current, and These are the proportionality coefficient and the bias term, respectively. and Using the nitrogen-vacancy fundamental amplitude as a reference target and minimizing the difference between the calibrated current amplitude and the reference target as the optimization direction, it is estimated in real time using an adaptive algorithm (such as recursive least squares method). The parameters are then adjusted using the recursive least squares algorithm. and Online identification and real-time updates are performed to ensure the calibrated current is accurate. Approximation in the least squares sense This enables dynamic compensation for temperature drift and long-term stability deviations of the TMR array.

[0042] Online drift compensation for the TMR array is achieved by estimating the scaling factor and / or bias term through recursive least squares, adaptive filtering, or Kalman filtering, and applying them to each channel respectively. When the estimated drift exceeds the threshold, an alarm is generated and the timestamp and compensation parameters are recorded.

[0043] The method in this embodiment can be run in real time using a sliding buffer, with the buffer length covering at least one cycle; when the fundamental frequency deviates from the preset range, it triggers a re-estimation of the fundamental frequency and updates the demodulation reference.

[0044] This embodiment of the method effectively suppresses the asymmetry and harmonic interference caused by the flip waveform by signal segmentation, half-cycle zeroing and fundamental frequency phase-locked demodulation without adding a bias magnet. It achieves stable extraction of the fundamental amplitude of the flip waveform, thereby providing an accurate reference for online monitoring and drift compensation of the TMR array and improving the long-term measurement accuracy and stability of the hybrid current sensor.

[0045] Figure 2A schematic diagram of the array-type current transformer structure constructed in this embodiment is provided; specifically, it includes: a ring-shaped insulating support frame, several magnetic field sensing units distributed on the frame, and a conductor under test located at the center; in this embodiment, there are a total of 8 magnetic field sensing units (numbered...). S 1 to S 8) The magnetic field sensing units are evenly distributed on a circumference with a radius of 35 mm at equal intervals, and the magnetic sensing direction of each unit is arranged tangentially along the circumference to detect the closed magnetic field generated by the current in the central conductor; the magnetic field sensing unit preferably uses a tunnel magnetoresistive chip (such as TMR2102), which has high sensitivity and linearity.

[0046] Figure 3 A schematic diagram of the nitrogen-vacancy center quantum sensor structure constructed in this embodiment is given; specifically, it includes: an NV center probe, responsible for measuring and sensing the magnetic field; a laser, responsible for applying a 532nm green laser to the NV center for polarization and providing reference light for the optical module; an optical module, which uses a differential optical path to obtain the fluorescence signal returned by the NV center to realize magnetic field measurement; and an electronics module, which processes the fluorescence signal of the NV center in real time and at high speed.

[0047] Figure 4 A schematic diagram of the hybrid current measurement system built in this embodiment is given. In the diagram, the nitrogen-vacancy color center quantum sensor and the array current sensor are synchronously sampled through the NI acquisition card to measure the same magnetic field, obtain the magnetic field signal of the NV color center and the magnetic field signal of TMR, and the amplitude can be monitored after data processing.

[0048] Figures 5(a) and (b) show the time-domain curves of the magnetic field output by the nitrogen-vacancy center quantum sensor without signal processing; Figure 5(a) is the time-domain curve of the magnetic field, and Figure 5(b) is a magnified view of a portion of the curve in Figure 5(a). It can be seen that without signal processing, because the NV center quantum sensor is insensitive to magnetic field direction information under the detection conditions of this embodiment, the output signal essentially represents the magnitude of the magnetic field. For alternating magnetic fields, when the original signal is in the negative half-cycle, the sensor output does not retain its sign information but outputs a positive value, causing the negative half-cycle waveform to flip to the positive half-axis, forming a flipped waveform. As a result, the output time-domain curve is significantly distorted compared to the original alternating magnetic field waveform, making it difficult to directly use for fundamental amplitude extraction.

[0049] Figure 6 The image shows the time-domain curve of the fundamental amplitude of the magnetic field obtained by directly extracting the fundamental amplitude of the output of the nitrogen-vacancy color center quantum sensor without signal processing. It can be seen that due to the flipping effect and asymmetric distortion of the original output waveform, the direct extraction of the fundamental amplitude is easily affected by waveform distortion and harmonic component interference, resulting in large fluctuations and poor stability of the obtained monitoring results, making it difficult to accurately reflect the true fundamental amplitude of the measured magnetic field.

[0050] Figure 7 This is a schematic diagram of half-cycle zeroing processing of the output signal of the nitrogen-vacancy color center quantum sensor. Specifically, based on the half-cycle segment boundary determined by the minimum point detection, the preprocessed output signal is segmented and gated within each complete cycle, so that half of the signal is retained and the other half is zeroed, thereby splitting the original inverted aliasing waveform into separately processed half-cycle signals, providing a basis for subsequent complementary sequence construction and fundamental amplitude extraction.

[0051] Figures 8(a) and (b) show the waveforms and magnified views of two complementary sequences obtained after half-cycle zeroing of the output signal of the nitrogen-vacancy color center quantum sensor, respectively. The two complementary sequences are constructed according to the methods of "preserving the first half-cycle and zeroing the second half-cycle" and "preserving the second half-cycle and zeroing the first half-cycle" within the same cycle, complementing each other in the time domain. By decomposing the original inverted waveform into two complementary signals, the influence of positive and negative half-cycle aliasing on the subsequent fundamental amplitude extraction can be effectively reduced.

[0052] Figure 9 This image shows the results of extracting and fusing the fundamental amplitudes of two complementary sequences from a nitrogen-vacancy color center quantum sensor. It can be seen that... Figure 6 Compared to the time-domain curve obtained by directly extracting the fundamental amplitude from the unprocessed output, Figure 9 The fusion results show smaller fluctuations and more stable overall changes, indicating that by setting the half-cycle to zero, constructing complementary sequences, and performing amplitude fusion processing, the interference of the flipped waveform and its asymmetric distortion on the fundamental amplitude extraction can be effectively suppressed, thereby improving the stability of the fundamental amplitude monitoring results.

[0053] Example 2 In one or more embodiments, a system for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor is disclosed, specifically comprising: The data acquisition module is configured to acquire and preprocess the raw signal output by the nitrogen-vacancy color center quantum sensor. The data segmentation module is configured to detect minimum points in the preprocessed signal, set minimum intervals and amplitude thresholds to eliminate false boundaries, and form stable half-cycle segments. The complementary sequence construction module is configured to construct two sets of complementary sequences based on half-cycle segments, so as to achieve the retention of the first half-cycle and the zeroing of the second half-cycle and the retention of the second half-cycle and the zeroing of the first half-cycle respectively in each cycle. The amplitude extraction module is configured to perform fundamental frequency phase-locked demodulation on two sets of complementary sequences to obtain two fundamental amplitude components; and to fuse the two fundamental amplitude components to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current.

[0054] As a further step, after obtaining the nitrogen-vacancy fundamental amplitude monitoring value, the method further includes: using the nitrogen-vacancy color center fundamental amplitude monitoring value to perform online compensation on the TMR array output.

[0055] As a further option, let's assume the TMR measurement result is... The calibrated current is: ; in, For the calibrated current, and These are the proportionality coefficient and the bias term, respectively.

[0056] As a further solution, a minimum interval and amplitude threshold are set to eliminate false boundaries, specifically: Set minimum interval With amplitude threshold Boundaries that do not meet the following conditions will be removed: ; ; in, for The signal after time-based preprocessing; and The detected numbers are respectively the first The and the first The moment of the minimum value point; and These are the preset minimum time interval threshold and amplitude threshold, respectively.

[0057] As a further approach, two sets of complementary sequences are constructed based on the semi-circular segmentation, specifically: First complementary sequence: ; First complementary sequence: ; in, and These represent the constructed first complementary sequence signal and the second complementary sequence signal, respectively. This represents the preprocessed nitrogen-vacancy color center magnetic field signal; , , The detected numbers are respectively the first The, the The and the first The moment of the minimum value point.

[0058] As a further approach, fundamental frequency phase-locked demodulation is performed on the two complementary sequences respectively, specifically as follows: Let the reference signal be: ; ; The specific calculation for fundamental frequency phase-locked demodulation is as follows: ; ; in, For the fundamental frequency, This represents the number of sampling points; , representing two sets of complementary sequences, and These represent the quadrature reference signals used for phase-locked demodulation; and They represent the first The discrete values ​​of the reference signal corresponding to each sampling point; Indicates the first The complementary sequence in the first group Discrete values ​​of each sampling point; and They represent the first, second, and third parts respectively. The in-phase and quadrature components obtained by demodulating complementary sequences.

[0059] As a further approach, the two fundamental amplitude components are fused to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current, specifically: ; ; in, This represents the amplitude component of the i-th roadbed wave.

[0060] It should be noted that the specific implementation methods of the above modules are the same as those in Example 1, and will not be described in detail again.

[0061] Example 3 In one or more embodiments, a terminal device is disclosed, comprising a processor and a memory, wherein the processor is configured to implement instructions; the memory is configured to store multiple instructions adapted to be loaded by the processor and executed by the processor to extract the amplitude of the flipped magnetic field of the nitrogen-vacancy color center quantum sensor described in Embodiment 1; the method includes: S101: Acquire the raw signal output by the nitrogen-vacancy color center quantum sensor and perform preprocessing; S102: Perform minimum point detection on the preprocessed signal, set minimum interval and amplitude threshold to eliminate false boundaries and form stable half-cycle segments; S103: Construct two sets of complementary sequences based on half-cycle segmentation, so as to achieve the retention of the first half-cycle and the setting of the second half-cycle to zero and the retention of the second half-cycle and the setting of the first half-cycle to zero respectively in each cycle; S104: Perform fundamental frequency phase-locked demodulation on the two complementary sequences respectively to obtain two fundamental amplitude components; fuse the two fundamental amplitude components to obtain the nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current.

[0062] As a further step, after obtaining the nitrogen-vacancy fundamental amplitude monitoring value, the method further includes: using the nitrogen-vacancy color center fundamental amplitude monitoring value to perform online compensation on the TMR array output.

[0063] As a further option, let's assume the TMR measurement result is... The calibrated current is: ; in, For the calibrated current, and These are the proportionality coefficient and the bias term, respectively.

[0064] As a further solution, a minimum interval and amplitude threshold are set to eliminate false boundaries, specifically: Set minimum interval With amplitude threshold Boundaries that do not meet the following conditions will be removed: ; ; in, for The signal after time-based preprocessing; and The detected numbers are respectively the first The and the first The moment of the minimum value point; and These are the preset minimum time interval threshold and amplitude threshold, respectively.

[0065] As a further approach, two sets of complementary sequences are constructed based on the semi-circular segmentation, specifically: First complementary sequence: ; First complementary sequence: ; in, and These represent the constructed first complementary sequence signal and the second complementary sequence signal, respectively. This represents the preprocessed nitrogen-vacancy color center magnetic field signal; , , The detected numbers are respectively the first The, the The and the first The moment of the minimum value point.

[0066] As a further approach, fundamental frequency phase-locked demodulation is performed on the two complementary sequences respectively, specifically as follows: Let the reference signal be: ; ; The specific calculation for fundamental frequency phase-locked demodulation is as follows: ; ; in, For the fundamental frequency, This represents the number of sampling points; , representing two sets of complementary sequences, and These represent the quadrature reference signals used for phase-locked demodulation; and They represent the first The discrete values ​​of the reference signal corresponding to each sampling point; Indicates the first The complementary sequence in the first group Discrete values ​​of each sampling point; and They represent the first, second, and third parts respectively. The in-phase and quadrature components obtained by demodulating complementary sequences.

[0067] As a further approach, the two fundamental amplitude components are fused to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current, specifically: ; ; in, This represents the amplitude component of the i-th roadbed wave.

[0068] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0069] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0070] In the implementation process, each step of the above method can be completed by the integrated logic circuits in the processor hardware or by software instructions.

[0071] Example 4 In one or more embodiments, a computer-readable storage medium is disclosed, storing a plurality of instructions adapted to be loaded by a processor of a terminal device and executed to extract the amplitude of the flipped magnetic field of the nitrogen-vacancy color center quantum sensor described in Embodiment 1; the method includes: S101: Acquire the raw signal output by the nitrogen-vacancy color center quantum sensor and perform preprocessing; S102: Perform minimum point detection on the preprocessed signal, set minimum interval and amplitude threshold to eliminate false boundaries and form stable half-cycle segments; S103: Construct two sets of complementary sequences based on half-cycle segmentation, so as to achieve the retention of the first half-cycle and the setting of the second half-cycle to zero and the retention of the second half-cycle and the setting of the first half-cycle to zero respectively in each cycle; S104: Perform fundamental frequency phase-locked demodulation on the two complementary sequences respectively to obtain two fundamental amplitude components; fuse the two fundamental amplitude components to obtain the nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current.

[0072] As a further step, after obtaining the nitrogen-vacancy fundamental amplitude monitoring value, the method further includes: using the nitrogen-vacancy color center fundamental amplitude monitoring value to perform online compensation on the TMR array output.

[0073] As a further option, let's assume the TMR measurement result is... The calibrated current is: ; in, For the calibrated current, and These are the proportionality coefficient and the bias term, respectively.

[0074] As a further solution, a minimum interval and amplitude threshold are set to eliminate false boundaries, specifically: Set minimum interval With amplitude threshold Boundaries that do not meet the following conditions will be removed: ; ; in, for The signal after time-based preprocessing; and The detected numbers are respectively the first The and the first The moment of the minimum value point; and These are the preset minimum time interval threshold and amplitude threshold, respectively.

[0075] As a further approach, two sets of complementary sequences are constructed based on the semi-circular segmentation, specifically: First complementary sequence: ; First complementary sequence: ; in, and These represent the constructed first complementary sequence signal and the second complementary sequence signal, respectively. This represents the preprocessed nitrogen-vacancy color center magnetic field signal; , , The detected numbers are respectively the first The, the The and the first The moment of the minimum value point.

[0076] As a further approach, fundamental frequency phase-locked demodulation is performed on the two complementary sequences respectively, specifically as follows: Let the reference signal be: ; ; The specific calculation for fundamental frequency phase-locked demodulation is as follows: ; ; in, For the fundamental frequency, This represents the number of sampling points; , representing two sets of complementary sequences, and These represent the quadrature reference signals used for phase-locked demodulation; and They represent the first The discrete values ​​of the reference signal corresponding to each sampling point; Indicates the first The complementary sequence in the first group Discrete values ​​of each sampling point; and They represent the first, second, and third parts respectively. The in-phase and quadrature components obtained by demodulating complementary sequences.

[0077] As a further approach, the two fundamental amplitude components are fused to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current, specifically: ; ; in, This represents the amplitude component of the i-th roadbed wave.

[0078] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor, characterized in that, include: The raw signal output by the nitrogen-vacancy color center quantum sensor was acquired and preprocessed. Minimum point detection is performed on the preprocessed signal, and minimum interval and amplitude threshold are set to eliminate false boundaries and form stable half-cycle segments; Two complementary sequences are constructed based on half-cycle segmentation to achieve the following in each cycle: retaining the first half-cycle and setting the second half-cycle to zero, and retaining the second half-cycle and setting the first half-cycle to zero, respectively. Two complementary sequences are demodulated using fundamental frequency phase-locked loop (PLL) to obtain two fundamental amplitude components. The two fundamental amplitude components are then fused to obtain a nitrogen-vacancy fundamental amplitude monitoring value that is proportional to the amplitude of the measured current.

2. The method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor as described in claim 1, characterized in that, After obtaining the nitrogen-vacancy fundamental amplitude monitoring value, the method further includes: using the nitrogen-vacancy color center fundamental amplitude monitoring value to perform online compensation on the TMR array output.

3. The method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor as described in claim 2, characterized in that, Assuming the TMR measurement result is The calibrated current is: ； in, For the calibrated current, and These are the proportionality coefficient and the bias term, respectively.

4. The method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor as described in claim 1, characterized in that, To eliminate false boundaries, a minimum interval and an amplitude threshold are set, specifically: Set minimum interval With amplitude threshold Boundaries that do not meet the following conditions will be removed: ； in, for The signal after time-based preprocessing; and The detected numbers are respectively the first The and the first The moment of the minimum value point; and These are the preset minimum time interval threshold and amplitude threshold, respectively.

5. The method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor as described in claim 1, characterized in that, Two sets of complementary sequences are constructed based on the semi-circular segmentation, specifically: First complementary sequence: ; First complementary sequence: ; in, and These represent the constructed first complementary sequence signal and the second complementary sequence signal, respectively. This represents the preprocessed nitrogen-vacancy color center magnetic field signal; , , The detected numbers are respectively the first The, the The and the first The moment of the minimum value point.

6. The method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor as described in claim 1, characterized in that, The two complementary sequences are demodulated using fundamental frequency phase-locked loop (PLL) as follows: Let the reference signal be: ； The specific calculation for fundamental frequency phase-locked demodulation is as follows: ； in, For the fundamental frequency, This represents the number of sampling points; , representing two sets of complementary sequences, and These represent the quadrature reference signals used for phase-locked demodulation; and They represent the first The discrete values ​​of the reference signal corresponding to each sampling point; Indicates the first The complementary sequence in the first group Discrete values ​​of each sampling point; and They represent the first, second, and third parts respectively. The in-phase and quadrature components obtained by demodulating complementary sequences.

7. The method for extracting the amplitude of the flipped magnetic field of a nitrogen-vacancy color center quantum sensor as described in claim 1, characterized in that, The two fundamental amplitude components are fused to obtain a nitrogen-vacancy fundamental amplitude monitoring value that is proportional to the amplitude of the measured current, specifically: ； ； in, This represents the amplitude component of the i-th roadbed wave.

8. A system for extracting the amplitude of a flipped magnetic field from a nitrogen-vacancy color center quantum sensor, characterized in that, include: The data acquisition module is configured to acquire and preprocess the raw signal output by the nitrogen-vacancy color center quantum sensor. The data segmentation module is configured to detect minimum points in the preprocessed signal, set minimum intervals and amplitude thresholds to eliminate false boundaries, and form stable half-cycle segments. The complementary sequence construction module is configured to construct two sets of complementary sequences based on half-cycle segments, so as to achieve the retention of the first half-cycle and the zeroing of the second half-cycle and the retention of the second half-cycle and the zeroing of the first half-cycle respectively in each cycle. The amplitude extraction module is configured to perform fundamental frequency phase-locked demodulation on two sets of complementary sequences to obtain two fundamental amplitude components; and to fuse the two fundamental amplitude components to obtain a nitrogen-vacancy fundamental amplitude monitoring quantity that is proportional to the amplitude of the measured current.

9. A terminal device comprising a processor and a memory, the processor for implementing instructions; the memory for storing multiple instructions, characterized in that, The instructions are adapted to be loaded by a processor and executed by the method for extracting the amplitude of the flipped magnetic field of the nitrogen-vacancy color center quantum sensor according to any one of claims 1-7.

10. A computer-readable storage medium storing a plurality of instructions, characterized in that, The instructions are adapted to be loaded by the processor of a terminal device and executed by the method for extracting the amplitude of the flipped magnetic field of the nitrogen-vacancy color center quantum sensor according to any one of claims 1-7.

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