Magnetic fluxgate multi-error correction method based on NV color center homologous decoupling

Abstract

This application belongs to the field of quantum sensing and magnetic field measurement correction technology, specifically relating to a fluxgate multi-error correction method based on NV color center co-source decoupling. This method arranges NV color center sensing units and triaxial fluxgate sensing units in close proximity to acquire the original triaxial magnetic field data of the fluxgate and the NV color center ODMR spectrum; calculates the reference magnetic field based on the ODMR resonance frequency shift, and extracts local temperature perturbations based on zero-field splitting changes; establishes a fluxgate error state model including zero-bias drift, temperature drift, scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error; and updates the error state model online using the reference magnetic field and local temperature perturbations to correct the fluxgate output in real time. This method achieves co-source acquisition of the magnetic field reference and temperature compensation, improving the long-term stability of the fluxgate, its temperature drift suppression capability, and the accuracy of magnetic anomaly measurement under complex environments.

Description

Technical Field

[0001] This application belongs to the field of quantum sensing and magnetic field measurement and correction technology, specifically involving a fluxgate multi-error correction method based on NV color center homogeneous decoupling. Background Technology

[0002] Fluxgate magnetometers are a type of commonly used weak magnetic field measurement sensor. They have advantages such as mature structure, small size, low power consumption, high sensitivity, fast dynamic response, and strong engineering adaptability. They are widely used in geomagnetic measurement, magnetic anomaly detection, attitude navigation, marine exploration, underground pipeline detection, underwater target detection, and magnetic measurement of unmanned mobile platforms.

[0003] In existing technologies, methods such as factory calibration, laboratory standard magnetic field calibration, temperature compensation, multi-position rotation calibration, zero bias estimation, filtering, or multi-sensor fusion are commonly used to improve the measurement accuracy of fluxgate magnetometers. For example, a standard magnetic field is generated using a Helmholtz coil to perform offline calibration of the fluxgate's zero bias and scaling factor; an external temperature sensor is used to collect ambient temperature and establish a fitting relationship between temperature and fluxgate zero bias; ellipsoidal fitting or multi-position rotation is used to correct triaxial non-orthogonal errors; and low-pass filtering, Kalman filtering, or moving average methods are used to suppress output noise. While these methods can improve the measurement performance of fluxgate magnetometers under certain conditions, they still have significant shortcomings.

[0004] Therefore, it is necessary to propose a new online correction method for fluxgate magnetometers, which can estimate and correct various types of fluxgate errors in real time using the same magnetic field-temperature information provided by the NV color center without relying on external standard magnetic field equipment. This would improve the measurement stability and magnetic anomaly identification accuracy of fluxgate magnetometers in long-term operation, temperature changes, complex magnetic environments, and mobile platform applications. Summary of the Invention

[0005] To address the problems that existing fluxgate magnetometers are prone to zero drift, temperature drift, scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error during long-term continuous operation, and that traditional offline calibration methods are difficult to adapt to real-time field correction, external temperature compensation suffers from temperature measurement position deviation and thermal hysteresis, and single fluxgate data is difficult to distinguish between real magnetic field changes and its own drift, this invention provides an online correction method for multiple errors of fluxgate magnetometers based on NV color center magnetic field-temperature homogeneous decoupling.

[0006] A fluxgate multi-error correction method based on NV color center homogeneous decoupling includes the following steps: S1. Fix the NV color center sensing unit and the three-axis fluxgate sensing unit on the same magnetic measuring carrier, and establish the coordinate transformation relationship between the NV crystal coordinate system, the NV sensing unit installation coordinate system, the fluxgate coordinate system and the magnetic measuring carrier coordinate system. S2. Synchronously acquire the raw triaxial magnetic field data output by the triaxial fluxgate sensing unit. , and the ODMR spectral data output by the NV color center sensing unit; S3. Perform multi-peak fitting on the same ODMR spectral data collected at the same time, extract at least three pairs of resonant frequencies corresponding to linearly independent NV orientations, and simultaneously obtain the differential mode frequency, common mode frequency and spectral quality parameters based on the pairs of resonant frequencies, wherein the differential mode frequency, common mode frequency and spectral quality parameters are derived from the same ODMR spectral data at the same time. S4. Calculate the magnetic field projection on each NV orientation based on the differential mode frequency, calculate the local temperature disturbance in the region where the NV color center is located based on the common mode frequency, and generate the NV reference data reliability based on the spectral quality parameters. S5. Reconstruct the NV three-dimensional reference magnetic field based on the magnetic field projections on at least three linearly independent NV orientations, and transform the NV three-dimensional reference magnetic field to the fluxgate coordinate system according to the coordinate transformation relationship in step S1 to obtain the NV reference magnetic field in the fluxgate coordinate system. ; S6. Establish a fluxgate multi-error state model, which includes an error matrix. Zero-bias drift vector and temperature drift vector The error matrix This includes scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error; S7. The NV reference magnetic field obtained synchronously from the same ODMR spectral data at the same time. Local temperature disturbance The reliability of the NV reference data is input into the fluxgate multi-error state model, and combined with the original triaxial magnetic field data. For the error matrix Zero-bias drift vector and temperature drift vector Perform online joint estimation; S8. Error matrix obtained from online joint estimation Zero-bias drift vector and temperature drift vector For the original triaxial magnetic field data Real-time corrections are performed to obtain corrected triaxial magnetic field data. ,in: ; in, The corrected triaxial magnetic field data, This is the original triaxial magnetic field data of the fluxgate magnetometer. Here is the error matrix. The zero-bias drift vector, This is the temperature drift vector.

[0007] Preferably, in step S1, the transformation relationship from the NV crystal coordinate system to the fluxgate coordinate system is expressed as follows: ; In the formula, To convert to the NV reference magnetic field in fluxgate coordinate system, The three-dimensional reference magnetic field in the NV crystal coordinate system. Let be the rotation matrix from the NV crystal coordinate system to the fluxgate coordinate system. Translational compensation or local gradient compensation introduced to compensate for differences in spatial location; Local magnetic field gradient compensation is expressed as: ; in, The local magnetic field gradient matrix, is the position difference vector between the NV color center sensing unit and the fluxgate sensing unit.

[0008] Preferably, in step S3, the paired resonant frequencies include the first resonant frequency under the same NV orientation. Second resonant frequency The differential-mode frequency and common-mode frequency are obtained as follows: Calculate the differential mode frequency based on the paired resonant frequencies. : ; Calculate common-mode frequency : .

[0009] Preferably, in step S4, the spectral quality parameters include at least two of the following: ODMR spectral line signal-to-noise ratio, spectral linewidth, resonance peak fitting residual, fluorescence contrast, and resonance frequency locking error; the NV reference data reliability is generated by weighting the spectral quality parameters and is used to adjust the weights of the NV reference magnetic field and local temperature perturbation in the fluxgate multi-error state model update.

[0010] Preferably, the local temperature disturbance is determined by the common-mode frequency corresponding to multiple NV orientations, and the non-temperature frequency shift error caused by crystal strain, electric field disturbance or optical power drift is suppressed by the consistency judgment of the common-mode frequency of multiple orientations.

[0011] Preferably, in step S6, the fluxgate multi-error state model is represented as follows: ; in, This is the original triaxial magnetic field data of the fluxgate magnetometer. The NV reference magnetic field in fluxgate coordinate system. Here is the error matrix. The zero-bias drift vector, This is the temperature drift vector. This refers to the residual term or measurement noise term. The error matrix Decomposed into: ; in, It is a three-axis scaling factor matrix. It is a three-axis non-orthogonal matrix. This is the inter-axis coupling matrix.

[0012] Preferably, each component of the temperature drift vector is constructed from the local temperature perturbation obtained by solving the NV color center. For the first... The temperature drift component of the shaft is expressed as: ; In the formula, Indicates fluxgate axis, shaft or axis, For the temperature drift vector at the th Components on the axis, For the first Temperature drift compensation coefficient corresponding to the shaft. This represents the local temperature perturbation calculated from the ODMR spectrum of the NV color center.

[0013] Preferably, the objective function for joint estimation in step S7 is: ; in, The length of the sliding window. For the first Weighting coefficients for time-matter data. These weighting coefficients are determined based on at least two of the following: the reliability of the NV reference data, the residual amplitude between the original three-axis magnetic field data of the fluxgate and the NV reference magnetic field, the rate of change of local temperature disturbance, and the magnitude of change in magnetic field direction.

[0014] Preferably, step S7 further includes a parameter update gating step: when the change amplitude of the NV reference magnetic field direction within the sliding window is lower than a preset excitation threshold, only the zero bias drift vector and temperature drift vector are updated, and the updates of the scaling factor error, triaxial non-orthogonality error, and interaxial coupling error are paused; when the ODMR spectral signal-to-noise ratio is lower than the first threshold, the ODMR spectral linewidth is higher than the second threshold, the residual amplitude between the original triaxial magnetic field data of the fluxgate and the NV reference magnetic field is higher than the third threshold, or the local temperature perturbation rate is higher than the fourth threshold, the weight of the data at the corresponding time moment in the update of the fluxgate multi-error state model is reduced, or the data at the corresponding time moment is paused from participating in the error matrix update.

[0015] Preferably, step S8 further includes a frequency division and fusion step: the triaxial magnetic field data corrected by the error matrix, zero-bias drift vector, and temperature drift vector is subjected to a high-pass filter to obtain a fast magnetic field change component; the NV reference magnetic field is subjected to a low-pass filter to obtain a low-frequency reference component; and the fast magnetic field change component and the low-frequency reference component are fused to obtain the final corrected triaxial magnetic field data; wherein the high-pass filter and the low-pass filter have the same or complementary cutoff frequencies, and the cutoff frequencies are determined based on at least one of the NV color center sensing unit sampling frequency, ODMR spectral quality parameter, fluxgate noise spectral density, and fluxgate zero-bias drift rate.

[0016] Compared with the prior art, the beneficial effects of this application are as follows:

[0017] First, this invention achieves simultaneous acquisition of the magnetic field reference and temperature compensation. Instead of using separate magnetic field sensors and external temperature sensors for calibration, this invention utilizes the ODMR spectrum of the NV color center at the same time to synchronously obtain the magnetic field projection, local temperature perturbation, and spectral quality parameters. This reduces the problems of inconsistent temperature measurement positions, thermal hysteresis, and inaccurate temperature compensation associated with traditional external temperature sensors, thus improving the reliability of fluxgate temperature drift correction.

[0018] Second, this invention enables online joint correction of multiple types of fluxgate errors. This invention establishes a multi-error state model of the fluxgate, including an error matrix, a zero-bias drift vector, and a temperature drift vector. Furthermore, it correlates the error matrix with scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error. Therefore, it can simultaneously correct the zero-bias drift, temperature drift, scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error of the fluxgate, avoiding the shortcomings of traditional methods that can only compensate for a single error source.

[0019] Third, this invention improves the stability and resilience to erroneous updates in the online correction process. It incorporates NV reference data reliability, spectral quality parameters, residual amplitude, temperature perturbation rate, and magnetic field direction variation amplitude, and performs weighted estimation and parameter update gating based on this information. When NV spectral quality deteriorates, magnetic field excitation is insufficient, or measurement residuals are abnormal, the weight of abnormal data can be reduced or partial parameter updates can be paused, thereby preventing the scaling factor, non-orthogonality error, and inter-axis coupling error from being incorrectly corrected.

[0020] Fourth, this invention combines the fast response capability of fluxgate magnetometers with the long-term stable reference capability of NV color centers. Fluxgate magnetometers have a high sampling rate and good dynamic response, making them suitable for capturing rapidly changing magnetic anomaly signals; NV color centers have good reference stability, making them suitable for providing low-frequency reference magnetic fields and local temperature information. This invention, through online joint estimation or frequency division fusion, allows fluxgate magnetometers to retain their fast response advantage while utilizing NV color centers to suppress low-frequency drift and temperature drift.

[0021] Fifth, this invention is applicable to long-term weak magnetic field measurements in complex environments. This invention does not rely on external standard magnetic field equipment for real-time correction and can continuously update the fluxgate error state model during on-site operation. It is suitable for scenarios requiring long-term stable magnetic field measurements, such as magnetic anomaly detection, geomagnetic navigation, magnetic surveying of unmanned platforms, submarine pipeline inspection, submarine cable detection, and underwater or underground magnetic target detection.

[0022] Sixth, this invention can improve the reliability of magnetic anomaly detection results. In magnetic anomaly detection applications, fluxgate baseline drift and temperature drift can affect anomaly peak identification, target location determination, and burial depth inversion. This invention uses the NV reference magnetic field to update the background magnetic field baseline and performs multi-error correction on the fluxgate data before extracting the magnetic anomaly peak, which can improve the accuracy of magnetic anomaly signal identification and the reliability of target parameter inversion. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0024] Figure 1 A schematic diagram of the close-proximity arrangement of the NV color center sensing unit and the fluxgate sensing unit; The components include: 1. NV color center sensing unit housing; 2. NV color center sensing chip; 3. First mounting bracket; 4. Fluxgate sensing unit housing; 5. Triaxial fluxgate sensing component; 6. Second mounting bracket; 7. Magnetic measuring carrier mounting base; and 8. Signal acquisition and processing module. Figure 2 This is a flowchart of the application process; Figure 3A schematic diagram illustrating the extraction of differential mode frequency, common mode frequency, and spectral quality parameters in ODMR spectra; Figure 4 Flowchart of fluxgate multi-error state model and online joint estimation; Figure 5 Flowchart for parameter update gating and frequency division fusion correction; Figure 6 This diagram illustrates background baseline updating and abnormal peak extraction in magnetic anomaly detection applications. Detailed Implementation

[0025] 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.

[0026] The NV color center sensing unit and the triaxial fluxgate sensing unit are fixedly mounted on the same magnetic measurement carrier. The magnetic measurement carrier can be a fixed magnetic measurement platform, a mobile magnetic measurement platform, an unmanned surface vessel, an unmanned aerial vehicle, an underwater vehicle, or other magnetic measurement equipment.

[0027] like Figure 1 As shown, the NV color center sensing unit and the triaxial fluxgate sensing unit are mounted in a close-proximity parallel configuration. The NV color center sensing unit includes an NV color center sensing unit housing 1 and an NV color center sensing chip 2 disposed inside or at the front measurement window. The NV color center sensing chip 2 generates an ODMR spectral signal under laser and microwave excitation, and provides a reference magnetic field, local temperature perturbation, and spectral quality parameters based on the ODMR spectral signal. The NV color center sensing unit housing 1 is fixed to the magnetic carrier mounting base 7 by a first mounting bracket 3. The first mounting bracket 3 defines the mounting position and orientation of the NV color center sensing unit and reduces mechanical vibration and relative displacement during measurement.

[0028] The three-axis fluxgate sensing unit includes a fluxgate sensing unit housing 4 and a three-axis fluxgate sensing component 5 disposed therein. The three-axis fluxgate sensing component 5 is used for outputting... axis, shaft and The original triaxial magnetic field data in the axial direction. The fluxgate sensor unit housing 4 is fixed to the same magnetic carrier mounting base 7 by the second mounting bracket 6. The second mounting bracket 6 is used to ensure that the triaxial fluxgate sensing component 5 has a stable mounting posture relative to the magnetic carrier mounting base 7. The first mounting bracket 3 and the second mounting bracket 6 are respectively set at adjacent positions on the magnetic carrier mounting base 7, so that the NV color center sensing chip 2 and the triaxial fluxgate sensing component 5 maintain a preset proximity distance, thereby placing them in the same or equivalently the same magnetic field environment to be measured after spatial compensation.

[0029] During assembly, the magnetic field carrier mounting base 7 is first fixed to a non-strong magnetic interference area of ​​the magnetic field measuring platform or moving carrier. Then, the NV color center sensing unit housing 1 is mounted on one side of the magnetic field carrier mounting base 7 via the first mounting bracket 3, with the sensitive surface of the NV color center sensing chip 2 facing the area of ​​the magnetic field to be measured. Subsequently, the fluxgate sensing unit housing 4 is mounted on the other side of the magnetic field carrier mounting base 7 via the second mounting bracket 6, ensuring that the three-axis directions of the three-axis fluxgate sensing component 5 are consistent with the preset fluxgate coordinate system. After installation, the relative position, installation angle, and coordinate transformation relationship between the NV color center sensing chip 2 and the three-axis fluxgate sensing component 5 are obtained through calibration or structural dimension measurement, so that the NV three-dimensional reference magnetic field can be converted to the fluxgate coordinate system in subsequent steps.

[0030] The signal acquisition and processing module 8 is located below or fixedly connected to the magnetic field carrier mounting base 7, and is electrically connected to both the NV color center sensing unit and the triaxial fluxgate sensing unit. The signal acquisition and processing module 8 provides laser, microwave, or readout control signals to the NV color center sensing unit, receives ODMR spectral data output from the NV color center sensing unit, and simultaneously receives raw triaxial magnetic field data output from the triaxial fluxgate sensing unit. It also performs time synchronization, buffering, and preprocessing on both types of data. Through this structural arrangement, the NV color center sensing unit provides co-source magnetic field-temperature reference information, the triaxial fluxgate sensing unit provides high-sampling-rate triaxial magnetic field output, and the signal acquisition and processing module 8 completes data synchronization and subsequent error correction calculations, thus providing the hardware foundation for establishing a fluxgate multi-error state model and performing online joint estimation.

[0031] This embodiment provides an online correction method for multiple errors of fluxgate magnetometers based on the decoupling of NV color center magnetic field and temperature. It is mainly used to solve the problems of zero drift, temperature drift, scale factor error, triaxial non-orthogonality error and inter-axis coupling error generated by fluxgate magnetometers during long-term operation.

[0032] A fluxgate multi-error correction method based on NV color center homogeneous decoupling includes the following steps: S1. Fix the NV color center sensing unit and the three-axis fluxgate sensing unit on the same magnetic measuring carrier, and establish the coordinate transformation relationship between the NV crystal coordinate system, the NV sensing unit mounting coordinate system, the fluxgate coordinate system, and the magnetic measuring carrier coordinate system.

[0033] Sensor unit deployment: The NV color center sensing unit and the triaxial fluxgate sensing unit are fixedly mounted on the same magnetic measurement carrier. The magnetic measurement carrier can be a fixed magnetic measurement platform, a mobile magnetic measurement platform, an unmanned surface vessel, an unmanned aerial vehicle, an underwater vehicle, or other magnetic measurement equipment.

[0034] The NV color center sensing unit and the triaxial fluxgate sensing unit are arranged in close proximity, so that they are in the same or equivalent magnetic field environment after spatial compensation. To avoid spatial magnetic field differences due to different installation positions, the following coordinate relationships are pre-established in this embodiment: NV crystal coordinate system; NV sensing unit installation coordinate system; fluxgate coordinate system; magnetic measuring carrier coordinate system.

[0035] The transformation relationship from the NV crystal coordinate system to the fluxgate coordinate system can be expressed as: ; In the formula, To convert to the NV reference magnetic field in fluxgate coordinate system, The three-dimensional reference magnetic field in the NV crystal coordinate system. Let be the rotation matrix from the NV crystal coordinate system to the fluxgate coordinate system. Translational compensation or local gradient compensation introduced to compensate for differences in spatial location. When the spatial distance between the NV color center sensing unit and the triaxial fluxgate sensing unit is less than the preset nearest neighbor distance, coordinate transformation can be performed directly based on the rotation matrix and installation offset compensation. When the spatial distance between them is greater than or equal to the preset nearest neighbor distance, local magnetic field gradient compensation is introduced. Preferably, the preset nearest neighbor distance is 5–50 mm.

[0036] The local magnetic field gradient compensation can be expressed as: ; In the formula, The local magnetic field gradient matrix, is the position difference vector between the NV color center sensing unit and the fluxgate sensing unit.

[0037] The local magnetic field gradient matrix can be obtained in any of the following ways: by spatial scanning results under a preset calibration magnetic field; by estimation by an auxiliary magnetic field sensor array set on the magnetic measurement carrier; or by fitting multi-position measurement data of the moving platform in a short period of time. By introducing local magnetic field gradient compensation, the reference error caused by the non-co-location of the NV color center sensing unit and the fluxgate sensing unit can be reduced.

[0038] S2. Synchronously acquire the raw triaxial magnetic field data output by the triaxial fluxgate sensing unit. , and the ODMR spectral data output by the NV color center sensing unit.

[0039] The raw triaxial magnetic field data output by the triaxial fluxgate sensing unit can be expressed as: ; In the formula, For the first Original triaxial magnetic field data in fluxgate coordinate system at any given time. , , They are fluxgates axis, shaft and The original magnetic field output of the axis.

[0040] Simultaneously, ODMR spectral data output from the NV color center sensing unit were acquired. The NV color center sensing unit obtains the ODMR spectrum through laser excitation, microwave frequency sweep, or microwave modulation. The ODMR spectrum contains resonance frequency information corresponding to multiple NV orientations.

[0041] In this embodiment, a diamond NV color center set with four crystal orientations is preferably used. However, in practical applications, as long as effective resonance information of at least three linearly independent NV orientations can be obtained, the three-dimensional reference magnetic field reconstruction can be completed.

[0042] S3. Perform multi-peak fitting on the same ODMR spectral data collected at the same time, extract at least three pairs of resonant frequencies corresponding to linearly independent NV orientations, and simultaneously obtain the differential mode frequency, common mode frequency, and spectral quality parameters based on the pairs of resonant frequencies, wherein the differential mode frequency, common mode frequency, and spectral quality parameters are derived from the same ODMR spectral data at the same time.

[0043] Multi-peak fitting was performed on the ODMR spectra acquired at the same time to extract at least three paired resonance frequencies corresponding to linearly independent NV orientations. For the first... For each NV orientation, its paired resonant frequency is denoted as: ,in, and These are two resonant frequencies generated by the magnetic field under the same NV orientation.

[0044] Calculate the differential mode frequency based on the paired resonant frequencies: ; And calculate the common-mode frequency: ; In the formula, Used for subsequent calculations Magnetic field projection on each NV orientation This is used for subsequent calculation of the local temperature disturbance in the region where the NV color center is located.

[0045] Simultaneously, spectral quality parameters are extracted from the same ODMR spectral data. These spectral quality parameters include at least two of the following: ODMR spectral signal-to-noise ratio, spectral linewidth, resonance peak fitting residual, fluorescence contrast, and resonance frequency locking error.

[0046] Therefore, in this embodiment, differential mode frequency, common mode frequency and spectral quality parameters are obtained simultaneously from the same ODMR spectral data at the same time, so that magnetic field reference information, temperature perturbation information and reference data quality evaluation information have the same data source and time reference.

[0047] S4. Calculate the magnetic field projection on each NV orientation based on the differential mode frequency, calculate the local temperature disturbance in the region where the NV color center is located based on the common mode frequency, and generate the NV reference data reliability based on the spectral quality parameters.

[0048] Based on the differential mode frequency at each NV orientation, the magnetic field projection at the corresponding orientation is obtained: ; In the formula, For the first Magnetic field projection on each NV orientation is the gyrometry of the electron spins of the NV color center.

[0049] Based on the common-mode frequency corresponding to each NV orientation, the local temperature disturbance in the region where the NV color center is located is calculated. For the first... For each NV orientation, the local temperature perturbation can be expressed as: ; In the formula, The zero-field splitting frequency at the reference temperature, This is the conversion coefficient between the zero-field splitting frequency and temperature.

[0050] Preferably, in this embodiment, the local temperature disturbance is determined by using common-mode frequencies from multiple NV orientations: ; In the formula, This represents the number of NV orientations involved in the temperature calculation. By determining the common-mode frequency consistency of multiple NV orientations, the influence of non-temperature factors such as crystal strain, electric field disturbances, and optical power fluctuations on the temperature calculation can be reduced.

[0051] NV reference data reliability is generated based on the spectral quality parameters. The reliability of the NV reference data is used to characterize the reliability of the NV reference magnetic field and local temperature perturbation in updating the fluxgate error model at the current moment. Normalized to the 0–1 range; when the ODMR spectral signal-to-noise ratio is high, the spectral linewidth is small, the fitting residual is small, the fluorescence contrast is high, and the resonance frequency locking error is small. Larger; conversely, Smaller.

[0052] Generation of spectral quality parameters and NV reference data reliability: After performing multi-peak fitting on the ODMR spectrum at each time point, not only are paired resonance frequencies extracted, but spectral quality parameters are also extracted simultaneously. These spectral quality parameters include at least two of the following: ODMR spectral signal-to-noise ratio, ODMR spectral linewidth, resonance peak fitting residual, fluorescence contrast, and resonance frequency locking error.

[0053] The ODMR spectral signal-to-noise ratio was normalized to Normalize the fluorescence contrast to Normalize the spectral linewidth to The residuals of the resonance peak fitting are normalized to Normalize the resonant frequency locking error to .in, and Positively correlated with credibility , and It is negatively correlated with credibility.

[0054] The reliability of the NV reference data can be obtained by the following formula: ; in, Let the weighting coefficients satisfy: ; And all weighting coefficients are not less than 0.

[0055] When the ODMR spectral signal-to-noise ratio is high, the spectral line is narrow, the fitting residual is small, the fluorescence contrast is high, and the resonance frequency locking error is small, the reliability of the NV reference data is high; conversely, the weight of the data at the corresponding time point in the online estimation is reduced. when When, reduce the weights of the NV reference magnetic field and local temperature perturbation in the model update at that moment; when At that time, the data is allowed to participate normally in the joint estimation of the error matrix, the zero bias drift vector, and the temperature drift vector.

[0056] Multi-orientation common-mode frequency consistency judgment: In complex environments, the common-mode frequency variation of NV centers is not necessarily caused entirely by temperature; it may also be affected by crystal strain, electric field disturbances, optical power variations, or microwave excitation drift. Therefore, this embodiment employs a common-mode frequency consistency determination method based on multiple NV orientations.

[0057] For multiple NV orientations, the common-mode frequency quantity Calculate their average value: ; And calculate the degree of dispersion of common-mode frequencies for multiple NV orientations: ; When the common-mode frequency discreteness of the multiple NV orientations Less than the preset consistency threshold At that time, it was assumed that the common-mode frequency variation mainly originated from temperature disturbances; when Greater than or equal to the preset consistency threshold If non-temperature frequency shift errors are found due to crystal strain, electric field disturbance, optical power drift, or microwave excitation drift, the weight of local temperature disturbance in temperature drift correction should be reduced, or the temperature drift parameter update should be paused.

[0058] The preset consistency threshold is set based on the standard deviation of the common-mode frequency dispersion obtained during the static non-magnetic disturbance calibration phase, and satisfies the following: ; In the formula, The standard deviation of the common-mode frequency dispersion during the static, disturbance-free calibration phase. Take 2 to 5.

[0059] when At that time, local temperature disturbances normally participate in temperature drift compensation; when When, reduce the temperature drift compensation weight; when When that time comes, pause the update of the temperature drift parameter at that moment.

[0060] S5. Reconstruct the NV three-dimensional reference magnetic field based on the magnetic field projections on at least three linearly independent NV orientations, and transform the NV three-dimensional reference magnetic field to the fluxgate coordinate system according to the coordinate transformation relationship in step S1 to obtain the NV reference magnetic field in the fluxgate coordinate system. .

[0061] The magnetic field projections on at least three linearly independent NV orientations are combined as follows: ; Let the projection matrix composed of the unit vectors of each NV orientation be... Then we have: ; When there are three NV orientations involved in the calculation, the three-dimensional reference magnetic field in the NV crystal coordinate system can be obtained by matrix inversion; when there are more than three NV orientations involved in the calculation, the three-dimensional reference magnetic field in the NV crystal coordinate system can be obtained by least squares. ; Then, based on the coordinate transformation relationship established in step S1, the NV three-dimensional reference magnetic field is transformed to the fluxgate coordinate system to obtain the NV reference magnetic field in the fluxgate coordinate system: ; In the formula, It serves as the reference magnetic field input in the subsequent fluxgate multi-error state model.

[0062] S6. Establish a fluxgate multi-error state model, which includes an error matrix. Zero-bias drift vector and temperature drift vector The error matrix This includes scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error.

[0063] Establish a multi-error state model for fluxgate magnetometers: ; In the formula, This is the original triaxial magnetic field data of the fluxgate magnetometer. The NV reference magnetic field in fluxgate coordinate system. Here is the error matrix. The zero-bias drift vector, This is the temperature drift vector. This is the residual term.

[0064] The error matrix A(t) can be further decomposed into: ; in, It is a three-axis scaling factor matrix. It is a three-axis non-orthogonal matrix. This is the inter-axis coupling matrix.

[0065] The temperature drift vector Each axis component is constructed from the local temperature perturbation obtained from the NV color center solution: ; in, Indicates fluxgate axis, shaft or axis, , , , This is the temperature drift compensation coefficient for the corresponding axis.

[0066] S7. The NV reference magnetic field obtained synchronously from the same ODMR spectral data at the same time. Local temperature disturbance The reliability of the NV reference data is input into the fluxgate multi-error state model, and combined with the original triaxial magnetic field data. For the error matrix Zero-bias drift vector and temperature drift vector Perform online joint estimation.

[0067] The NV reference magnetic field obtained synchronously from the same ODMR spectral data at the same time Local temperature disturbance and NV reference data credibility The fluxgate multi-error state model is input together, and combined with the original triaxial magnetic field data of the fluxgate. For the error matrix Zero-bias drift vector and temperature drift vector Perform online joint estimation.

[0068] Online joint estimation is performed using sliding window least squares, recursive least squares, or Kalman filtering methods. Within the sliding window, the objective function can be expressed as: ; In the formula, The length of the sliding window. For the first Weighting coefficients for time-matter data. These weighting coefficients are determined based on at least two of the following: the reliability of the NV reference data, the residual amplitude between the original three-axis magnetic field data of the fluxgate and the NV reference magnetic field, the rate of change of local temperature disturbance, and the magnitude of change in magnetic field direction. Through the above online joint estimation, the NV color center is not only used as an independent magnetometer to output magnetic field value, but also participates in the online joint update of the fluxgate error matrix, zero bias drift vector and temperature drift vector by using the reference magnetic field, local temperature perturbation and reference data obtained synchronously from the same ODMR spectrum, thereby realizing the real-time correction of multiple types of errors of the fluxgate magnetometer.

[0069] Weight coefficients in online joint estimation: In this embodiment, the weighting coefficients in the sliding window estimation are jointly determined by the reliability of the NV reference data, the residual amplitude between the fluxgate and the NV reference magnetic field, the rate of change of local temperature perturbation, and the magnitude of change of magnetic field direction, and are normalized to the 0-1 range.

[0070] The residual amplitude between the original triaxial magnetic field data of the fluxgate and the NV reference magnetic field can be expressed as: .

[0071] The rate of change of local temperature disturbance can be expressed as: .

[0072] The magnitude of the change in the direction of the NV reference magnetic field within the sliding window can be expressed as: ; in, and Both belong to sliding windows .

[0073] The weighting coefficient can be determined by the following formula: ; In the formula, For residual weighting terms, The weighting term is the rate of temperature change. This is the weighting term for the change in the direction of the magnetic field.

[0074] The residual weight term can be expressed as: .

[0075] The weighted term for the rate of temperature change can be expressed as: .

[0076] The weighting term for the change in magnetic field direction can be expressed as: when < hour, ; when ≥ hour, ; in, The residual threshold, The threshold for the rate of temperature change. This is a preset excitation threshold.

[0077] By using the above method, when the NV spectral quality decreases, the residual between the fluxgate and the NV reference magnetic field increases, the temperature changes rapidly, or the magnetic field direction changes insufficiently, the weight of the data at the corresponding moment is automatically reduced, thereby avoiding abnormal data from causing incorrect updates of the fluxgate error parameters.

[0078] Parameter update gating:

[0079] During the online joint estimation process, if the change in the NV reference magnetic field direction within the sliding window is lower than the preset excitation threshold, it indicates that the current magnetic field direction excitation is insufficient, and the scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error are not sufficiently observable. In this case, this embodiment only updates the zero-bias drift vector and the temperature drift vector, pausing the updating of the scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error in the error matrix.

[0080] Specifically, when the following conditions are met: < At that time, execute: ; and only for and Update.

[0081] When continuous Each sliding window satisfies ≥ And the NV reference data reliability meets the requirements. ≥ And the residual amplitude satisfies < At that time, recover the error matrix Online updates. Preferably, Take 2 to 5. Take a value of 0.6 to 0.8. Take a range of 3° to 15°.

[0082] By setting recovery conditions, frequent start-stop updates of the error matrix can be avoided when there are short-term disturbances, unstable spectral quality, or insufficient magnetic field excitation.

[0083] Anomaly Gating: If any of the following occurs, reduce the weight of the data at the corresponding time step, or suspend the data at the corresponding time step from participating in the error matrix update: The signal-to-noise ratio of the ODMR spectral lines is below the first threshold. ODMR spectral linewidth is higher than the second threshold; The residual amplitude between the original triaxial magnetic field data of the fluxgate and the NV reference magnetic field is higher than the third threshold. The rate of change of local temperature disturbance is higher than the fourth threshold. The common-mode frequency dispersion corresponding to multiple NV orientations is higher than the preset consistency threshold.

[0084] The first, second, third, and fourth thresholds are determined during the initial stabilization calibration phase. During the initial stabilization calibration phase, NV center ODMR spectral data and fluxgate raw triaxial magnetic field data are collected for no less than 60 seconds. The mean signal-to-noise ratio, mean spectral linewidth, mean residual amplitude, mean local temperature perturbation rate of change, and their corresponding standard deviations are calculated, and each gating threshold is set accordingly.

[0085] This abnormal gating mechanism can prevent incorrect updates of fluxgate error parameters when there is poor NV spectral quality, strong external interference, sudden fluxgate drift, or rapid temperature changes.

[0086] Corrected output: After completing the spectral quality reliability calculation, common-mode frequency consistency judgment, weight coefficient generation, and parameter update gating, the corrected fluxgate triaxial magnetic field data is still output in the manner described in Example 1: .

[0087] Compared with Example 1, this example does not redefine a separate fluxgate correction process. Instead, based on the complete process of Example 1, it further defines the reliability of NV reference data, the consistency judgment of local temperature disturbances, the online estimation weight allocation, and the parameter update gating rules, thereby improving the stability and reliability of the online correction method under complex temperature changes, spectral quality fluctuations, insufficient magnetic field excitation, or local magnetic interference conditions.

[0088] S8, NV color center assisted fluxgate online correction algorithm.

[0089] The error matrix obtained from online joint estimation Zero-bias drift vector and temperature drift vector The original triaxial magnetic field data of the fluxgate is corrected in real time to obtain the corrected triaxial magnetic field data: ; In the formula, This is the corrected triaxial magnetic field data.

[0090] Through the above method, this embodiment fully realizes the entire process of sensor unit deployment, synchronous acquisition, ODMR spectral decoupling, magnetic field projection and local temperature disturbance calculation, NV reference magnetic field reconstruction, fluxgate multi-error state model establishment, online joint estimation, and real-time correction of fluxgate output. This ensures that magnetic field information, temperature information, and spectral quality information all originate from the same ODMR spectral data at the same time, thereby improving the long-term measurement stability of fluxgate and the error suppression capability under complex environments.

[0091] This embodiment provides a specific way to apply the present invention to magnetic anomaly detection scenarios, which is applicable to scenarios such as submarine pipeline inspection, submarine cable detection, underwater metal target detection, underground pipeline detection, unmanned surface vessel magnetic surveying, and unmanned aerial vehicle magnetic surveying.

[0092] In this type of scenario, fluxgate magnetometers have a high sampling rate and good dynamic response, making them suitable for continuously capturing rapidly changing magnetic anomaly signals; NV color center sensing units have good long-term stability and co-source temperature decoupling capability, making them suitable for providing a low-frequency background magnetic field baseline and temperature compensation reference. Therefore, this embodiment adopts a frequency division and fusion method of "fluxgate high-frequency response + NV low-frequency reference".

[0093] 1. Measurement platform and sensor deployment:

[0094] The NV color center sensing unit, the three-axis fluxgate sensing unit, the positioning module, and the attitude module are fixedly mounted on the same mobile magnetometry platform. The mobile magnetometry platform can be an unmanned surface vessel, a drone, an underwater towed vehicle, a pipeline inspection vehicle, or other mobile measurement equipment.

[0095] Before the measurement begins, establish the coordinate transformation relationship between the NV color center sensing unit, the three-axis fluxgate sensing unit, the positioning module, and the magnetometry platform. If necessary, initial calibration can be performed using known directional magnetic fields or known track data.

[0096] 2. Continuous magnetic field acquisition: The mobile magnetic measurement platform moves along the preset measurement line, and the three-axis fluxgate sensor unit continuously outputs raw three-axis magnetic field data. The NV color center sensing unit synchronously or periodically acquires ODMR spectral data and calculates the NV reference magnetic field according to the method in Example 1. Local temperature disturbance And the reliability of NV reference data.

[0097] Using the method described in Example 1 or Example 2, the original three-axis magnetic field data of the fluxgate is corrected for zero bias, temperature drift, scaling factor, non-orthogonality, and inter-axis coupling errors to obtain the fluxgate data after preliminary correction.

[0098] 3. Frequency division fusion: To simultaneously preserve the fast dynamic response capability of fluxgate magnetization and the low drift reference capability of NV color centers, high-pass filtering is applied to the original or preliminarily corrected triaxial magnetic field data of fluxgate magnetization to obtain the fast magnetic field change components: ; or: .

[0099] Low-pass filtering of the NV reference magnetic field yields the low-frequency background reference component: ; By combining the two, we obtain the final corrected triaxial magnetic field data: ; The high-pass filter and low-pass filter have the same or complementary cutoff frequencies. The cutoff frequencies can be set or adaptively adjusted according to at least one of the following: NV color center sensing unit sampling frequency, ODMR spectral quality parameter, fluxgate noise spectral density, and fluxgate zero-bias drift rate.

[0100] When the NV spectral quality is good and the fluxgate drift is significant, increase the weight of the NV low-frequency reference in the fusion result; when the NV spectral quality deteriorates or the sampling interval is long, decrease the weight of the NV low-frequency reference and rely more on the continuous output of the fluxgate over a short period of time.

[0101] 4. Background magnetic field baseline update: In magnetic anomaly detection, magnetic anomalies caused by the target magnetic field typically manifest as local peaks, valleys, or abrupt gradient changes relative to the background magnetic field. To reduce the impact of low-frequency fluxgate drift on magnetic anomaly identification, this embodiment utilizes the NV reference magnetic field to update the background magnetic field baseline.

[0102] The background magnetic field baseline can be represented as: ; in, As the baseline of the background magnetic field, This indicates low-pass filtering. NV is the reference magnetic field in fluxgate coordinate system.

[0103] Background subtraction was performed on the final corrected triaxial magnetic field data to obtain magnetic anomaly data: ; in, Magnetic anomaly data after removing low-frequency background.

[0104] in, This is the final corrected triaxial magnetic field data obtained after frequency division and fusion. The magnetic anomaly data after removing the background magnetic field.

[0105] 5. Extraction of magnetic anomaly peaks: According to the magnetic anomaly data The method extracts at least one feature from the following: abnormal peak value, abnormal valley value, peak-valley distance, abnormal width, abnormal gradient, and abnormal duration distance. For pipeline, cable, or long strip-shaped magnetic targets, when the moving magnetic measurement platform moves along a measurement line perpendicular or oblique to the target's extension direction, the magnetic anomaly curve forms local peaks or valleys near the target. The positioning coordinates corresponding to the peaks or valleys are used as candidate locations for the magnetic target to be measured.

[0106] When a designed route, historical route, or preset reference route exists, the candidate location is compared with the designed route, historical route, or preset reference route to obtain the offset of the magnetic target to be measured. When it is necessary to estimate the burial depth or relative distance, the burial depth or relative distance of the magnetic target to be measured is calculated using a preset magnetic anomaly inversion model or historical calibration relationship, combining at least one of the following characteristics: magnetic anomaly amplitude, anomaly width, peak-to-valley spacing, and magnetic anomaly gradient.

[0107] 6. Output results: The final output should include at least one of the following results: corrected triaxial magnetic field data; background-removed magnetic anomaly data; magnetic anomaly peak position; position of the magnetic target to be measured; offset of the magnetic target to be measured; burial depth or relative distance of the magnetic target to be measured; and data reliability evaluation results.

[0108] This embodiment effectively reduces the impact of low-frequency baseline drift and temperature drift during long-distance inspection of fluxgate magnetometers, improving the stability of magnetic anomaly peak identification and the reliability of target positioning, offset calculation, and burial depth inversion.

[0109] It should be noted that the above embodiments are merely preferred implementations of the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the core concept of the present invention, those skilled in the art can adaptively adjust the installation distance between the NV color center sensing unit and the triaxial fluxgate sensing unit, the ODMR spectral acquisition method, the multi-peak fitting algorithm, the types of spectral quality parameters, the weighting coefficient calculation method, the sliding window length, the gate threshold, the filter cutoff frequency, and the specific expression of the fluxgate error state model according to specific application scenarios. As long as the above adjustments are still based on synchronously decoupling the same ODMR spectral data at the same time to obtain the magnetic field projection, local temperature perturbation, and NV reference data reliability, and the three types of homogeneous information are used together for the online joint update of the fluxgate error matrix, the zero-bias drift vector, and the temperature drift vector, they should be considered to fall within the scope of protection of the present invention. The essence of this invention is not a simple parallel combination of NV color center magnetometry, NV color center thermometry, and fluxgate compensation, but rather the establishment of a closed-loop online correction mechanism for multiple fluxgate error states using homologous spectral information. This enables coordinated compensation for zero-bias drift, temperature drift, scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error. All equivalent substitutions, parameter transformations, adjustments to the sequence of steps, or non-substantial improvements made based on the technical concept of this invention should be included within the scope of protection of this invention.

[0110] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fluxgate multi-error correction method based on NV color center homologous decoupling, characterized in that, Includes the following steps: S1. Fix the NV color center sensing unit and the three-axis fluxgate sensing unit on the same magnetic measuring carrier, and establish the coordinate transformation relationship between the NV crystal coordinate system, the NV sensing unit installation coordinate system, the fluxgate coordinate system and the magnetic measuring carrier coordinate system. S2, synchronously collecting raw three-axis magnetic field data output by the three-axis fluxgate sensor unit and ODMR spectrum data output by the NV color center sensor unit and the ODMR spectrum data output by the NV color center sensor unit S3. Perform multi-peak fitting on the same ODMR spectral data collected at the same time, extract at least three pairs of resonant frequencies corresponding to linearly independent NV orientations, and simultaneously obtain the differential mode frequency, common mode frequency and spectral quality parameters based on the pairs of resonant frequencies, wherein the differential mode frequency, common mode frequency and spectral quality parameters are derived from the same ODMR spectral data at the same time. S4. Calculate the magnetic field projection on each NV orientation based on the differential mode frequency, calculate the local temperature disturbance in the region where the NV color center is located based on the common mode frequency, and generate the NV reference data reliability based on the spectral quality parameters. S5. Reconstruct the NV three-dimensional reference magnetic field based on the magnetic field projections on at least three linearly independent NV orientations, and transform the NV three-dimensional reference magnetic field to the fluxgate coordinate system according to the coordinate transformation relationship in step S1 to obtain the NV reference magnetic field in the fluxgate coordinate system. ; S6. Establish a fluxgate multi-error state model, which includes an error matrix. Zero-bias drift vector and temperature drift vector The error matrix This includes scaling factor error, triaxial non-orthogonality error, and inter-axis coupling error; S7. The NV reference magnetic field obtained synchronously from the same ODMR spectral data at the same time. Local temperature disturbance The reliability of the NV reference data is input into the fluxgate multi-error state model, and combined with the original triaxial magnetic field data. For the error matrix Zero-bias drift vector and temperature drift vector Perform online joint estimation; S8. Error matrix obtained from online joint estimation Zero-bias drift vector and temperature drift vector For the original triaxial magnetic field data Real-time corrections are performed to obtain corrected triaxial magnetic field data. ,in: ； in, The corrected triaxial magnetic field data. This is the original triaxial magnetic field data of the fluxgate magnetometer. Here is the error matrix. The zero-bias drift vector, This is the temperature drift vector.

2. The fluxgate multi-error correction method based on NV color center homogeneous decoupling according to claim 1, characterized in that, In step S1, the transformation relationship from the NV crystal coordinate system to the fluxgate coordinate system is expressed as follows: ； In the formula, To convert to the NV reference magnetic field in fluxgate coordinate system, The three-dimensional reference magnetic field in the NV crystal coordinate system. Let be the rotation matrix from the NV crystal coordinate system to the fluxgate coordinate system. Translational compensation or local gradient compensation introduced to compensate for differences in spatial location; Local magnetic field gradient compensation is expressed as: ； in, The local magnetic field gradient matrix, is the position difference vector between the NV color center sensing unit and the fluxgate sensing unit.

3. The fluxgate multi-error correction method based on NV color center homogeneous decoupling according to claim 1, characterized in that, In step S3, the paired resonant frequencies include the first resonant frequency under the same NV orientation. Second resonant frequency The differential-mode frequency and common-mode frequency are obtained as follows: Calculate the differential mode frequency based on the paired resonant frequencies. : ； Calculate common-mode frequency : 。 4. The fluxgate multi-error correction method based on NV color center decoupling according to claim 1, characterized in that, In step S4, the spectral quality parameters include at least two of the following: ODMR spectral line signal-to-noise ratio, spectral linewidth, resonance peak fitting residual, fluorescence contrast, and resonance frequency locking error; the NV reference data reliability is generated by weighting the spectral quality parameters and is used to adjust the weights of the NV reference magnetic field and local temperature perturbation in the fluxgate multi-error state model update.

5. The fluxgate multi-error correction method based on NV color center homogeneous decoupling according to claim 1, characterized in that, The local temperature disturbance is determined by the common-mode frequency corresponding to multiple NV orientations, and the non-temperature frequency shift error caused by crystal strain, electric field disturbance or optical power drift is suppressed by the consistency judgment of the common-mode frequency of multiple orientations.

6. The fluxgate multi-error correction method based on NV color center decoupling according to claim 1, characterized in that, In step S6, the fluxgate multi-error state model is represented as follows: ； in, This is the original triaxial magnetic field data of the fluxgate magnetometer. The NV reference magnetic field in fluxgate coordinate system. Here is the error matrix. The zero-bias drift vector, This is the temperature drift vector. This refers to the residual term or measurement noise term. The error matrix Decomposed into: ； in, It is a three-axis scaling factor matrix. It is a three-axis non-orthogonal matrix. This is the inter-axis coupling matrix.

7. The fluxgate multi-error correction method based on NV color center homogeneous decoupling according to claim 6, characterized in that, Each component of the temperature drift vector is constructed from the local temperature perturbation obtained by solving the NV color center. For the ... The temperature drift component of the shaft is expressed as: ； In the formula, Indicates fluxgate axis, shaft or axis, For the temperature drift vector at the th Components on the axis, For the first Temperature drift compensation coefficient corresponding to the shaft. This represents the local temperature perturbation calculated from the ODMR spectrum of the NV color center.

8. The fluxgate multi-error correction method based on NV color center decoupling according to claim 1, characterized in that, The objective function for joint estimation in step S7 is: ； in, The length of the sliding window. For the first The weighting coefficients for the time data are determined based on at least two of the following: the reliability of the NV reference data, the residual amplitude between the original three-axis magnetic field data of the fluxgate and the NV reference magnetic field, the rate of change of local temperature disturbance, and the magnitude of change of magnetic field direction.

9. The fluxgate multi-error correction method based on NV color center homogeneous decoupling according to claim 1, characterized in that, Step S7 also includes a parameter update gating step: when the change amplitude of the NV reference magnetic field direction within the sliding window is lower than the preset excitation threshold, only the zero bias drift vector and temperature drift vector are updated, and the updates of the scaling factor error, triaxial non-orthogonality error and interaxial coupling error are paused; when the ODMR spectral signal-to-noise ratio is lower than the first threshold, the ODMR spectral linewidth is higher than the second threshold, the residual amplitude between the original triaxial magnetic field data of the fluxgate and the NV reference magnetic field is higher than the third threshold, or the local temperature perturbation rate is higher than the fourth threshold, the weight of the corresponding data in the fluxgate multi-error state model update is reduced, or the participation of the corresponding data in the error matrix update is paused.

10. The fluxgate multi-error correction method based on NV color center homogeneous decoupling according to claim 1, characterized in that, Step S8 further includes a frequency division and fusion step: the triaxial magnetic field data corrected by the error matrix, zero-bias drift vector, and temperature drift vector is subjected to a high-pass filter to obtain a fast magnetic field change component; the NV reference magnetic field is subjected to a low-pass filter to obtain a low-frequency reference component; and the fast magnetic field change component and the low-frequency reference component are fused to obtain the final corrected triaxial magnetic field data; wherein the high-pass filter and the low-pass filter have the same or complementary cutoff frequencies, and the cutoff frequencies are determined based on at least one of the NV color center sensing unit sampling frequency, ODMR spectral quality parameters, fluxgate noise spectral density, and fluxgate zero-bias drift rate.

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