A magnetic field measurement method for a fluxgate sensor

Abstract

The invention discloses a magnetic field measuring method of a fluxgate sensor, belonging to the technical field of electromagnetic detection. The invention places the fluxgate sensor at a calibrated ambient temperature, and applies an excitation signal with a linear frequency conversion to collect an induced voltage signal; then, the collected induced voltage signal is segmented according to the frequency duration to obtain a plurality of induced voltage sub-signals, and the temperature value corresponding to each sub-signal is recorded; then, the signal quality is calculated according to the spectrum information of the sub-signals, and a plurality of sub-signals with the best quality are selected; subsequently, the magnetic field components are calculated for these signals, and stable magnetic field components are screened out; finally, correction is performed according to the deviation between the temperature value of the stable magnetic field component and the calibrated ambient temperature to obtain the corrected magnetic field component, and the magnetic field intensity is calculated. The invention effectively improves the magnetic field measuring accuracy of the fluxgate sensor.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic detection, and in particular to a magnetic field measuring method of a fluxgate sensor. Background Art

[0002] In the research and application of fluxgate sensors, magnetic fields of different intensities have put forward differentiated technical requirements for the frequency of excitation signals. Traditional magnetic measurement technology usually uses an excitation signal with a fixed frequency. This single frequency method is difficult to adapt to the precise measurement requirements under different magnetic field intensities. In the existing technology, engineers have found that for magnetic fields of different intensities, using the same frequency excitation signal will result in a significant decrease in measurement accuracy. Low-intensity magnetic fields require higher-frequency excitation signals to improve sensitivity, while high-intensity magnetic fields require lower-frequency excitation signals to avoid signal saturation and distortion. Therefore, for magnetic fields of different intensities, the most suitable frequencies are different. When using an incompatible frequency for magnetic measurement, there is a problem of low magnetic measurement accuracy. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, a magnetic field measurement method of a fluxgate sensor provided by the present invention solves the problem of low magnetic field measurement accuracy in the prior art.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: a magnetic field measurement method of a fluxgate sensor, comprising the following steps:

[0005] S1. Place the fluxgate sensor at a calibrated ambient temperature, apply an excitation signal with a linear frequency conversion to the fluxgate sensor, and collect an induced voltage signal;

[0006] S2, segmenting the induced voltage signal according to the frequency duration to obtain a plurality of induced voltage sub-signals, and recording the temperature value on the fluxgate sensor when collecting each induced voltage sub-signal;

[0007] S3, calculating the signal quality evaluation value of each induced voltage sub-signal according to the spectrum information of the induced voltage sub-signal, and selecting multiple induced voltage sub-signals with the best quality;

[0008] S4, calculating the magnetic field component for each induced voltage sub-signal with the best signal quality, and screening out the stable magnetic field component;

[0009] S5. According to the deviation between the temperature value corresponding to the stable magnetic field component and the calibrated ambient temperature, the stable magnetic field component is corrected to obtain the corrected magnetic field component, and the magnetic field intensity is calculated.

[0010] Furthermore, the expression of the excitation signal in S1 is: , where I(t) is the excitation signal, A is the amplitude of the excitation signal, and f 0is the initial frequency, T is the frequency duration, t is the current time point, is rounded down, sin is the sine function, and the initial frequency is f 0 1KHz, When the frequency is greater than 10KHz, stop applying the excitation signal.

[0011] Furthermore, S3 includes the following sub-steps:

[0012] S31, performing time-frequency transformation on the induced voltage sub-signal according to the period to obtain spectrum information;

[0013] S32, calculating a signal quality evaluation value of each induced voltage sub-signal according to the spectrum information of each cycle;

[0014] S33. Arrange the induced voltage sub-signals in descending order according to the signal quality evaluation values, take the first L induced voltage sub-signals, and obtain a plurality of induced voltage sub-signals with the best quality, where L is a positive integer.

[0015] Furthermore, the expression for calculating the signal quality evaluation value of each induced voltage sub-signal in S32 is: , where P is the signal quality assessment value, α s is the fundamental frequency amplitude stability, α c is the amplitude contrast.

[0016] Furthermore, the fundamental frequency amplitude stability α s The calculation formula is: , where V i,0 is the amplitude corresponding to the fundamental frequency in the spectrum information of the i-th cycle, N is the number of cycles in an induced voltage sub-signal, and i is the number of the cycle.

[0017] Furthermore, the amplitude contrast α c The formula is: , where V i,0 is the amplitude corresponding to the fundamental frequency in the spectrum information of the i-th period, V i,2 is the amplitude corresponding to the second harmonic frequency in the spectrum information of the i-th cycle, V i,j is the amplitude corresponding to the jth frequency in the spectrum information of the i-th period excluding the fundamental frequency and the second harmonic frequency, i is the period number, j is the frequency number, M is the number of frequencies in the spectrum information of the i-th period excluding the fundamental frequency and the second harmonic frequency, and N is the number of periods in an induced voltage sub-signal.

[0018] Further, S4 includes the following sub-steps:

[0019] S41, extracting the amplitude corresponding to the fundamental frequency of each cycle, the amplitude corresponding to the second harmonic frequency and the phase in each induced voltage sub-signal with the best signal quality, and calculating the magnetic field component corresponding to each induced voltage sub-signal;

[0020] S42, constructing a magnetic field component vector by taking each magnetic field component as an element in the order of occurrence in time;

[0021] S43, setting a sliding sequence with a length of 3 to slide on the magnetic field component vector, advancing one element each time;

[0022] S44, calculating a magnetic field component fluctuation value during each sliding;

[0023] S45. Select the magnetic field component corresponding to the minimum magnetic field component fluctuation value as the stable magnetic field component.

[0024] Furthermore, the formula for calculating the magnetic field component corresponding to each induced voltage sub-signal in S41 is: , where H n is the magnetic field component corresponding to the nth induced voltage sub-signal, V 0,c,n is the mean value of the amplitude corresponding to the fundamental frequency of each period in the nth induced voltage sub-signal, V 2,c,n is the average value of the amplitude corresponding to the second harmonic frequency of each period in the nth induced voltage sub-signal, K is the sensitivity coefficient of the fluxgate sensor, sin is the sine function, φ n is the phase mean of each cycle in the nth induced voltage sub-signal, and n is the number of the induced voltage sub-signal.

[0025] Further, S5 includes the following sub-steps:

[0026] S51, calculating the deviation according to the difference between the temperature value corresponding to the stable magnetic field component and the calibrated ambient temperature;

[0027] S52, using the deviation degree to correct the stable magnetic field component to obtain a corrected magnetic field component;

[0028] S53, taking the average of each corrected magnetic field component to obtain the magnetic field intensity.

[0029] Furthermore, the formula for calculating the degree of deviation in S51 is: , the corrected formula in S52 is: , where H revise,m is the mth corrected magnetic field component, H s,m is the mth stable magnetic field component, ε is the temperature correction coefficient, μ m is the deviation corresponding to the mth stable magnetic field component, K m is the temperature value corresponding to the mth stable magnetic field component, K enviris the calibrated ambient temperature, γ is the denominator adjustment coefficient, and m is a positive integer.

[0030] The beneficial effects of the present invention are:

[0031] 1. The present invention applies an excitation signal with a linear frequency transformation to the fluxgate sensor to obtain an induced voltage signal, and segments the induced voltage signal according to the duration of each frequency to obtain multiple induced voltage sub-signals, which is equivalent to an induced voltage sub-signal corresponding to the excitation signal at each frequency. Then, multiple induced voltage sub-signals with the best quality are screened out, that is, the induced voltage sub-signal corresponding to the most suitable magnetic measurement frequency is found, and then the magnetic field component is calculated for each induced voltage sub-signal, the stable magnetic field component is screened out, the inaccurate magnetic field component is discarded, and the stable magnetic field component is corrected to further improve the calculation accuracy of the magnetic field strength.

[0032] 2. The present invention applies an excitation signal with a linear frequency transformation to the fluxgate sensor, which is equivalent to using excitation signals of different frequencies, extracting the induced voltage sub-signals with good signal quality, thereby screening out the induced voltage sub-signals corresponding to the adaptive frequency under the current magnetic field strength, discarding other induced voltage sub-signals, and improving the magnetic measurement accuracy.

[0033] 3. The present invention collects the temperature value corresponding to each induced voltage sub-signal, and corrects the stable magnetic field component through the deviation between the temperature value and the calibrated ambient temperature, thereby further improving the accuracy of calculating the magnetic field strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a flow chart of a magnetic field measurement method of a fluxgate sensor.

[0035] Figure 2 Schematic diagram of 1KHz excitation signal.

[0036] Figure 3 Schematic diagram of 1.1KHz excitation signal.

[0037] Figure 4 Schematic diagram of 1.2KHz excitation signal. DETAILED DESCRIPTION

[0038] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0039] like Figure 1 As shown, a magnetic field measurement method of a fluxgate sensor comprises the following steps:

[0040] S1. Place the fluxgate sensor at a calibrated ambient temperature, apply an excitation signal with a linear frequency conversion to the fluxgate sensor, and collect an induced voltage signal;

[0041] S2, segmenting the induced voltage signal according to the frequency duration to obtain a plurality of induced voltage sub-signals, and recording the temperature value on the fluxgate sensor when collecting each induced voltage sub-signal;

[0042] S3, calculating the signal quality evaluation value of each induced voltage sub-signal according to the spectrum information of the induced voltage sub-signal, and selecting multiple induced voltage sub-signals with the best quality;

[0043] S4, calculating the magnetic field component for each induced voltage sub-signal with the best signal quality, and screening out the stable magnetic field component;

[0044] S5. According to the deviation between the temperature value corresponding to the stable magnetic field component and the calibrated ambient temperature, the stable magnetic field component is corrected to obtain the corrected magnetic field component, and the magnetic field intensity is calculated.

[0045] In this embodiment, the expression of the excitation signal in S1 is: , where I(t) is the excitation signal, A is the amplitude of the excitation signal, and f 0 is the initial frequency, T is the frequency duration, t is the current time point, is rounded down, sin is the sine function, and the initial frequency is f 0 1KHz, When the frequency is greater than 10KHz, stop applying the excitation signal.

[0046] The excitation signal of the present invention adopts a frequency range of 1kHz to 10kHz. Lower frequencies (such as below 1kHz) are easily affected by power supply noise and environmental interference, while higher frequencies (such as above 10kHz) may introduce more high-frequency noise. Selecting the range of 1kHz to 10kHz can achieve a balance between signal strength and noise suppression.

[0047] When T is set to 2 seconds, in this formula, f 0 is the initial frequency (e.g. 1kHz), and It means that the frequency will gradually increase as time goes by. Since T=2 seconds, the frequency change will be adjusted every 2 seconds. In the present invention, when T is set to 2 seconds, the induced voltage signal is segmented by 2 seconds to obtain multiple induced voltage sub-signals, that is, an excitation signal of one frequency corresponds to one induced voltage sub-signal.

[0048] Figure 2 This is the waveform of the excitation signal in the first 2 seconds, and its frequency is 1KHz; Figure 3 This is the waveform of the excitation signal in the second 2 seconds, and its frequency is 1.1KHz; Figure 4 This is the waveform of the excitation signal in the third 2 seconds, and its frequency is 1.2KHz.

[0049] In this embodiment, S3 includes the following sub-steps:

[0050] S31, performing time-frequency transformation on the induced voltage sub-signal according to the period to obtain spectrum information;

[0051] S32, calculating a signal quality evaluation value of each induced voltage sub-signal according to the spectrum information of each cycle;

[0052] S33. Arrange the induced voltage sub-signals in descending order according to the signal quality evaluation values, take the first L induced voltage sub-signals, and obtain a plurality of induced voltage sub-signals with the best quality, where L is a positive integer.

[0053] Since the excitation signal input by the present invention is a periodic sine wave, the period length of which is fixed, therefore, the present invention performs time-frequency transformation on the induced voltage sub-signal according to the period (the period is the same as the period of the sine wave) to obtain the spectrum information of each period, that is, the induced voltage sub-signal is divided according to the period length, and the time-frequency transformation is performed in each period. According to the spectrum information of an induced voltage sub-signal corresponding to each period, the signal quality evaluation value of each induced voltage sub-signal is calculated, and L induced voltage sub-signals with good signal quality are selected. In this embodiment, when the upper frequency limit is 10Kz, there are 90 frequencies corresponding to 90 induced voltage sub-signals. L of the present invention can be set to 10, and 10 induced voltage sub-signals are selected.

[0054] In the present invention, the fundamental frequency is the frequency value corresponding to the maximum amplitude of a cycle.

[0055] In this embodiment, the expression for calculating the signal quality evaluation value of each induced voltage sub-signal in S32 is: , where P is the signal quality assessment value, α s is the fundamental frequency amplitude stability, α c is the amplitude contrast.

[0056] In this embodiment, the fundamental frequency amplitude stability α s The calculation formula is: , where V i,0 is the amplitude corresponding to the fundamental frequency in the spectrum information of the i-th cycle, N is the number of cycles in an induced voltage sub-signal, and i is the number of the cycle.

[0057] In this embodiment, the amplitude contrast α c The formula is: , where V i,0is the amplitude corresponding to the fundamental frequency in the spectrum information of the i-th period, V i,2 is the amplitude corresponding to the second harmonic frequency in the spectrum information of the i-th cycle, V i,j is the amplitude corresponding to the jth frequency in the spectrum information of the i-th period excluding the fundamental frequency and the second harmonic frequency, i is the period number, j is the frequency number, M is the number of frequencies in the spectrum information of the i-th period excluding the fundamental frequency and the second harmonic frequency, and N is the number of periods in an induced voltage sub-signal.

[0058] Since the present invention inputs a single frequency (for one moment) sinusoidal signal, the fundamental frequency amplitude stability α s By calculating the deviation between the fundamental frequency amplitude fluctuation and its average value in each cycle, the stability of the signal can be evaluated. The stability of the fundamental frequency can reflect the overall quality of the signal. Then, by comparing the amplitude of other frequencies to the amplitude of the fundamental frequency and the amplitude of the second harmonic, the nonlinear characteristics and distortion of the signal can be further determined, thereby more comprehensively evaluating the signal quality.

[0059] In fluxgate sensors, the relationship between the second harmonic and magnetic field strength stems from the nonlinear magnetization characteristics of magnetic materials. As the magnetic field strength increases, the magnetic domain wall undergoes irreversible movement and reorientation, resulting in significant nonlinear behavior in the magnetization process. In the low magnetic field region, the magnetization process is basically linear; as the magnetic field strength increases, the magnetic domain wall undergoes complex displacement and flipping, resulting in nonlinear distortion, causing the second harmonic amplitude to grow rapidly. In theory, the second harmonic amplitude has a nonlinear relationship with the magnetic field strength. This nonlinear relationship reflects the complex changes in the magnetic domain structure inside the magnetic material and is an important feature of magnetic field measurement in fluxgate sensors.

[0060] In this embodiment, S4 includes the following sub-steps:

[0061] S41, extracting the amplitude corresponding to the fundamental frequency of each cycle, the amplitude corresponding to the second harmonic frequency and the phase in each induced voltage sub-signal with the best signal quality, and calculating the magnetic field component corresponding to each induced voltage sub-signal;

[0062] S42, constructing a magnetic field component vector by taking each magnetic field component as an element in the order of occurrence in time;

[0063] S43, setting a sliding sequence with a length of 3 to slide on the magnetic field component vector, advancing one element each time;

[0064] S44, calculating a magnetic field component fluctuation value during each sliding;

[0065] S45. Select the magnetic field component corresponding to the minimum magnetic field component fluctuation value as the stable magnetic field component.

[0066] The present invention extracts the fundamental frequency and second harmonic information from the induced voltage sub-signal with the best quality, eliminates the influence of other noises, improves the accuracy of calculating the magnetic field components, and then arranges the magnetic field components in the order of occurrence in time to form a magnetic field component vector, and finds out several stable magnetic field components with the smallest fluctuations. This can ensure that the selected magnetic field components are the most stable in time and avoid abnormal values ​​affecting the calculation accuracy.

[0067] In this embodiment, the magnetic field component fluctuation value is specifically: the variance or standard deviation of the covering element under the sliding sequence.

[0068] In this embodiment, the length of the sliding sequence may also be set to 4 or 5.

[0069] In this embodiment, the formula for calculating the magnetic field component corresponding to each induced voltage sub-signal in S41 is: , where H n is the magnetic field component corresponding to the nth induced voltage sub-signal, V 0,c,n is the mean value of the amplitude corresponding to the fundamental frequency of each period in the nth induced voltage sub-signal, V 2,c,n is the average value of the amplitude corresponding to the second harmonic frequency of each period in the nth induced voltage sub-signal, K is the sensitivity coefficient of the fluxgate sensor, sin is the sine function, φ n is the phase mean of each cycle in the nth induced voltage sub-signal, and n is the number of the induced voltage sub-signal.

[0070] The present invention combines the fundamental frequency amplitude and the second harmonic amplitude, and can comprehensively consider the main components of the signal and its nonlinear characteristics, thereby providing more comprehensive magnetic field information. By introducing the phase, the influence of the phase change of the signal on the magnetic field component can be considered. This helps to improve the stability and accuracy of the calculation results, especially in a dynamic environment.

[0071] In this embodiment, the sensitivity coefficient K refers to the responsiveness of the fluxgate sensor to an input signal (such as a change in magnetic field). It indicates the proportional relationship between the sensor output signal (such as voltage or current) and the input signal (such as magnetic field strength). Specifically, the higher the sensitivity coefficient, the more sensitive the sensor is to a change in magnetic field. The sensitivity coefficient K can be obtained by looking up the technical manual of the fluxgate sensor.

[0072] For general fluxgate sensors, the sensitivity range is usually between 0.1V / T and 0.5V / T. For example, some high-sensitivity fluxgate sensors may have a sensitivity of 0.5V / T.

[0073] In this embodiment, S5 includes the following sub-steps:

[0074] S51, calculating the deviation according to the difference between the temperature value corresponding to the stable magnetic field component and the calibrated ambient temperature;

[0075] S52, using the deviation degree to correct the stable magnetic field component to obtain a corrected magnetic field component;

[0076] S53, taking the average of each corrected magnetic field component to obtain the magnetic field intensity.

[0077] In this embodiment, the formula for calculating the deviation degree in S51 is: , the corrected formula in S52 is: , where H revise,m is the mth corrected magnetic field component, H s,m is the mth stable magnetic field component, ε is the temperature correction coefficient, μ m is the deviation corresponding to the mth stable magnetic field component, K m is the temperature value corresponding to the mth stable magnetic field component, K envir is the calibrated ambient temperature, γ is the denominator adjustment coefficient, and m is a positive integer.

[0078] In this embodiment, the calibrated ambient temperature is 25°.

[0079] Since the present invention places the fluxgate sensor at the calibration ambient temperature, the initial temperature of the fluxgate sensor is the calibration ambient temperature. When the power-on time is longer, the temperature of the fluxgate sensor increases with time. As the temperature increases, the induced voltage output by the sensor decreases. Therefore, the temperature correction coefficient has a value range of 0 to 0.5, and the temperature correction coefficient is used to offset the influence of temperature.

[0080] The present invention applies an excitation signal with a linear frequency transformation to a fluxgate sensor to obtain an induced voltage signal, and segments the induced voltage signal according to the duration of each frequency to obtain a plurality of induced voltage sub-signals, which is equivalent to an induced voltage sub-signal corresponding to the excitation signal at each frequency, and then screens out a plurality of induced voltage sub-signals with the best quality, that is, finds the induced voltage sub-signal corresponding to the most suitable magnetic measurement frequency, and then calculates the magnetic field component for each induced voltage sub-signal, screens out the stable magnetic field component, discards the inaccurate magnetic field component, and then corrects the stable magnetic field component, so as to further improve the calculation accuracy of the magnetic field strength.

[0081] The present invention applies an excitation signal with a linear frequency transformation to the fluxgate sensor, which is equivalent to using excitation signals of different frequencies, extracting induced voltage sub-signals with good signal quality, thereby screening out induced voltage sub-signals corresponding to the adaptive frequency under the current magnetic field strength, discarding other induced voltage sub-signals, and improving the magnetic measurement accuracy.

[0082] The present invention collects the temperature value corresponding to each induced voltage sub-signal, and corrects the stable magnetic field component through the deviation between the temperature value and the calibrated ambient temperature, thereby further improving the accuracy of calculating the magnetic field strength.

[0083] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A magnetic field measurement method of a fluxgate sensor, characterized in that: The following steps are involved: S1. Place the fluxgate sensor at a calibrated ambient temperature, apply a frequency linearly transformed excitation signal to the fluxgate sensor, and collect an induced voltage signal; S2, segmenting the induced voltage signal according to the frequency duration to obtain a plurality of induced voltage sub-signals, and recording the temperature value on the fluxgate sensor when collecting each induced voltage sub-signal; S3, calculating the signal quality evaluation value of each induced voltage sub-signal according to the spectrum information of the induced voltage sub-signal, and selecting multiple induced voltage sub-signals with the best quality; S4, calculating the magnetic field component for each induced voltage sub-signal with the best signal quality, and screening out the stable magnetic field component; S5. According to the deviation between the temperature value corresponding to the stable magnetic field component and the calibrated ambient temperature, the stable magnetic field component is corrected to obtain a corrected magnetic field component, and the magnetic field intensity is calculated; The S3 comprises the following sub-steps: S31, performing time-frequency transformation on the induced voltage sub-signal according to the period to obtain spectrum information; S32, calculating a signal quality evaluation value of each induced voltage sub-signal according to the spectrum information of each cycle; S33, arranging the induced voltage sub-signals in descending order according to the signal quality evaluation values, taking the first L induced voltage sub-signals, and obtaining a plurality of induced voltage sub-signals with the best quality, where L is a positive integer; The expression for calculating the signal quality evaluation value of each induced voltage sub-signal in S32 is: , where P is the signal quality assessment value, α s is the fundamental frequency amplitude stability, α c is the amplitude contrast; The fundamental frequency amplitude stability α s The calculation formula is: , where V i,0 is the amplitude corresponding to the fundamental frequency in the spectrum information of the i-th cycle, N is the number of cycles in an induced voltage sub-signal, and i is the number of the cycle; The amplitude contrast α c The formula is: , where V i,0 is the amplitude corresponding to the fundamental frequency in the spectrum information of the i-th period, V i,2 is the amplitude corresponding to the second harmonic frequency in the spectrum information of the i-th cycle, V i,j is the amplitude corresponding to the jth frequency in the spectrum information of the i-th period except the fundamental frequency and the second harmonic frequency, i is the number of the period, j is the number of the frequency, M is the number of frequencies in the spectrum information of the i-th period except the fundamental frequency and the second harmonic frequency, and N is the number of periods in an induced voltage sub-signal; The S4 comprises the following sub-steps: S41, extracting the amplitude corresponding to the fundamental frequency of each cycle, the amplitude corresponding to the second harmonic frequency and the phase in each induced voltage sub-signal with the best signal quality, and calculating the magnetic field component corresponding to each induced voltage sub-signal; S42, constructing a magnetic field component vector by taking each magnetic field component as an element in the order of occurrence in time; S43, setting a sliding sequence with a length of 3 to slide on the magnetic field component vector, advancing one element each time; S44, calculating a magnetic field component fluctuation value during each sliding; S45. Select the magnetic field component corresponding to the minimum magnetic field component fluctuation value as the stable magnetic field component.

2. The magnetic field measurement method of the fluxgate sensor according to claim 1, characterized in that: The expression of the excitation signal in S1 is: , where I(t) is the excitation signal, A is the amplitude of the excitation signal, f0 is the initial frequency, T is the frequency duration, and t is the current time point. To round down, sin is the sine function, the initial frequency f0 is 1KHz, When the frequency is greater than 10KHz, stop applying the excitation signal.

3. The magnetic field measurement method of the fluxgate sensor according to claim 1, characterized in that: The formula for calculating the magnetic field component corresponding to each induced voltage sub-signal in S41 is: , where H n is the magnetic field component corresponding to the nth induced voltage sub-signal, V 0,c,n is the mean value of the amplitude corresponding to the fundamental frequency of each period in the nth induced voltage sub-signal, V 2,c,n is the average value of the amplitude corresponding to the second harmonic frequency of each period in the nth induced voltage sub-signal, K is the sensitivity coefficient of the fluxgate sensor, sin is the sine function, φ n is the phase mean of each cycle in the nth induced voltage sub-signal, and n is the number of the induced voltage sub-signal.

4. The magnetic field measurement method of the fluxgate sensor according to claim 1, characterized in that: The S5 comprises the following sub-steps: S51, calculating the deviation according to the difference between the temperature value corresponding to the stable magnetic field component and the calibrated ambient temperature; S52, using the deviation degree to correct the stable magnetic field component to obtain a corrected magnetic field component; S53, taking the average of each corrected magnetic field component to obtain the magnetic field intensity.

5. The magnetic field measurement method of the fluxgate sensor according to claim 4, characterized in that: The formula for calculating the deviation in S51 is: , the corrected formula in S52 is: , where H revise,m is the mth corrected magnetic field component, H s,m is the mth stable magnetic field component, ε is the temperature correction coefficient, μ m is the deviation corresponding to the mth stable magnetic field component, K m is the temperature value corresponding to the mth stable magnetic field component, K envir is the calibrated ambient temperature, γ is the denominator adjustment coefficient, and m is a positive integer.

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