A Fluxgate Anti-Interference Method and Device Based on Waveform Feature Classification

Abstract

The present invention relates to the field of measuring magnetic variables, and in particular to a fluxgate anti-interference method and device based on waveform feature classification, including: exciting a probe with an excitation signal of a required frequency; referring to the phase of the excitation signal, obtaining the induction signal of the probe, and obtaining the current magnetic induction intensity through digital signal processing of the induction signal within the sampling window; receiving the induction signal, identifying the signal form, and marking the abnormal phase, and then cutting off the abnormal signal; performing magnetic field data calculation on the induction signal after cutting off the abnormal signal to obtain the current magnetic induction intensity measurement value; outputting the data after processing the current magnetic induction intensity measurement value. Based on the analysis of the physical characteristics of the fluxgate probe, the present invention distinguishes the signal effectiveness through the method of feature space vector distance classification, so it is more accurate and reliable, and has the characteristics of being real-time and fast.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring magnetic variables, and specifically to a fluxgate anti-interference method and device based on waveform feature classification. Background Art

[0002] A fluxgate magnetometer is a main instrument for magnetic field measurement and can measure the three-component spatial vector magnetic field. The fluxgate magnetometer has the advantages of low power consumption, small volume, high precision, good reliability, etc., and is currently widely used in the fields of aviation, aerospace, and ground magnetic field measurement. The fluxgate magnetometer converts the low-frequency magnetic field signal in space into an electrical signal through an excitation coil and an induction coil, by means of the fluxgate effect of a soft magnetic core. In order to improve the accuracy of the fluxgate magnetometer in measuring the spatial magnetic field, its induction coil usually has very high sensitivity to achieve precise detection of the external magnetic field. However, at the same time, high-frequency electromagnetic wave signals will also be picked up by the highly sensitive induction coil. If the frequency of the high-frequency electromagnetic wave signal is close to the excitation frequency of the fluxgate magnetometer, it will cause great interference to the measurement data of the fluxgate.

[0003] Generally, a closed-loop measurement fluxgate magnetometer includes five main modules, namely: a fluxgate probe, an excitation module, an induction module, a feedback module, and a comprehensive control module. The comprehensive control module controls the excitation module to generate an excitation signal; the excitation signal excites a symmetric alternating magnetic field on the excitation coil of the fluxgate probe, causing the magnetic core of the probe to be periodically saturated; the periodic saturation magnetic field of the magnetic core is superimposed on the external magnetic field to be measured, generating an asymmetric alternating current signal with the information of the external magnetic field to be measured on the induction coil, which is called an induction signal; the induction module picks up the induction signal, performs a series of pre-processing, and extracts the information of the external magnetic field to be measured; the comprehensive control module performs post-processing on the information of the external magnetic field to be measured, outputs data, and guides the feedback module to perform feedback; the feedback module generates a feedback signal to form a quasi-direct current feedback signal in the feedback coil of the probe to cancel the magnetic field strength in the space where the probe is located. This process is called the closed-loop control of the fluxgate magnetometer. The actually measured magnetic induction intensity of the closed-loop fluxgate magnetometer should be the sum of the magnetic induction intensity measured by the induction module and the feedback magnetic induction intensity of the feedback module.

[0004] The operation of the fluxgate probe is based on the fluxgate effect and is mainly used to measure low-frequency magnetic fields. Taking a common toroidal core parallel fluxgate magnetometer with an excitation frequency of 10 kHz as an example, the second harmonic on the induction coil, that is, the 20 kHz induction current signal, will carry the information of the external magnetic field due to the fluxgate effect. The signal intensity of the second harmonic is generally positively correlated with the external magnetic induction intensity.

[0005] However, the fluxgate probe itself has a similar structure to the detection coil magnetometer that is sensitive to high-frequency signals. The detection coil magnetometer is sensitive to high-frequency magnetic field fluctuations, so high-frequency magnetic field fluctuations will be induced by this parasitic detection coil.

[0006] In actual operation, quasi-dc to ultra-low frequency magnetic field fluctuations below the 100 Hz magnitude will be captured by the fluxgate effect and are generally considered effective magnetic field signals to be measured, which will be extracted by the fluxgate magnetometer. Magnetic field fluctuations above 100 Hz and below the 1 kHz magnitude, although they can be captured by the fluxgate effect, will be filtered out by the digital low-pass filtering method of the magnetometer integrated control module. Magnetic field fluctuations above the 50 kHz magnitude will not be captured by the fluxgate effect but will be induced by the aforementioned structure similar to the detection coil magnetometer, and this part of the signal is filtered out by the hardware analog low-pass filtering of the magnetometer induction module. However, magnetic field fluctuation signals with frequencies close to the excitation waveform (10 kHz) and the second harmonic (20 kHz), that is, in the frequency range of about 5 kHz to 30 kHz, including pulses, sine waves, etc., this frequency range is the range of interest of the instrument, and digital and analog filtering methods cannot eliminate them. Once there is a strong interference with a characteristic frequency close to 20 kHz, it will directly damage the measurement data of the fluxgate magnetometer.

[0007] Generally, in scientific research and surveying work, the fluxgate magnetometer probe is often kept as far away from interference as possible. For example, it is installed on a magnetically clean boom tens of meters away from interference or placed in a magnetically clean room without electromagnetic interference sources to avoid interference.

[0008] At present, in the fields of industrial production, medical inspection, and the Internet of Things, the application demand for precise magnetic field measurement is increasing continuously. In these environments, if one wants to apply a fluxgate magnetometer, due to cost control and complex working conditions requirements, it is impossible to achieve perfect magnetic cleanliness measures similar to those in scientific research and surveying activities. The anti-interference ability of the fluxgate magnetometer applied to these fields needs to be improved urgently.

[0009] The waveform of the induction signal of a normally operating fluxgate has its expected morphological characteristics. If the fluxgate magnetometer is strongly interfered with, its actual morphological characteristics will deviate from the expected ones. In the related fields of machine learning, the morphological characteristics are usually summarized as vectors in the feature space, and the difference between the two morphological characteristics can be expressed as the norm of the difference between the corresponding two vectors in the feature space. Summary of the Invention

[0010] The purpose of the present invention is to provide a fluxgate anti-interference method and device based on waveform feature classification to solve the problems raised in the above background technology.

[0011] To achieve the above purpose, the present invention provides the following technical solutions:

[0012] A fluxgate anti-interference method based on waveform feature classification, comprising the steps:

[0013] S110. Excite the probe with an excitation signal of a required frequency;

[0014] S120. Refer to the phase of the reference excitation signal to obtain the induced signal of the probe;

[0015] S130. Obtain the current magnetic induction intensity by subjecting the induced signal within the sampling window to digital signal processing;

[0016] S140. Capture the induced signal, identify the signal form, mark the abnormal phase, and then cut off the abnormal signal;

[0017] S150. Perform magnetic field data calculation on the induced signal after cutting off the abnormal signal to obtain the current magnetic induction intensity measurement value;

[0018] S160. Output the data after processing the current magnetic induction intensity measurement value.

[0019] Further, the receiving the induced signal, identifying the signal form, marking the abnormal phase, and then cutting off the abnormal signal includes:

[0020] Receiving the induced signal, comparing it with the waveform feature database in real time, and selecting the abnormal waveform;

[0021] Subsequently, mark the phase where the abnormal waveform is located with reference to the excitation waveform, and determine the start and end positions and length of the abnormal signal;

[0022] Finally, cut off the abnormal signal part.

[0023] Further, the current window magnetic induction intensity measurement value is obtained by calculating with the remaining normal signals after cutting off the abnormal signal; the current window magnetic induction intensity measurement value is used as the new feedback magnetic induction intensity signal of the fluxgate probe; if the abnormal signal exceeds the sampling window length, the current window magnetic induction measurement value is output as empty; the current magnetic induction intensity measurement value is used as the new feedback magnetic induction signal of the excitation probe, converted into a feedback current, and fed back to the probe through the feedback module; if the current magnetic induction intensity measurement value is empty, the feedback signal of the previous moment is maintained; the current magnetic induction intensity measurement value is output after being processed with time stamping and compression.

[0024] Furthermore, the eigenvectors of the induced waveform are extracted from the even-order waveforms formed by the fluxgate effect of the probe, and a feature library is established. The feature space distance between the morphological eigenvectors of the input induced waveform and the standard normal waveform is calculated in real time. According to the waveform morphology in the measurement environment, the judgment threshold of the feature space distance between the morphological eigenvectors of the normal waveform and the standard normal waveform is determined. In an interference environment, once the feature space distance between the morphological eigenvectors of the induced waveform and the standard normal waveform exceeds the threshold, it is considered that an abnormal waveform morphology is found.

[0025] Furthermore, after an abnormal waveform morphology is found, the abnormal flag bit is suspended, the starting phase of the abnormal waveform is marked, and the waveform morphology is continuously monitored until the interference ends and the abnormal waveform morphology disappears. Subsequently, the ending phase of the abnormal waveform is marked, and the abnormal flag bit is released.

[0026] To achieve the above object, the present invention also provides the following technical solutions:

[0027] A fluxgate anti-interference device based on waveform feature classification, comprising:

[0028] An excitation module for outputting an excitation signal of a required frequency to excite the probe;

[0029] An induction module for obtaining the induction signal of the probe with reference to the phase of the excitation signal;

[0030] A waveform feature classification anti-interference module for receiving the induction signal, identifying the signal morphology, marking the abnormal phase, and then removing the abnormal signal;

[0031] An integrated control module for performing magnetic field data calculation on the induction signal after removing the abnormal signal to obtain the current magnetic induction intensity measurement value; and for outputting the data after processing the current magnetic induction intensity measurement value; specifically, the integrated control module is used to control the normal operation of all the above modules and package and output the data of the current true magnetic induction intensity value.

[0032] Furthermore, a feedback module for outputting a quasi-direct current feedback current signal to generate a feedback magnetic field on the probe to maintain the probe operating within the required (smaller) magnetic field dynamic range.

[0033] Furthermore, the waveform feature classification anti-interference module includes:

[0034] An identification unit for receiving the induction signal, comparing the waveform feature database in real time, and selecting the abnormal waveform;

[0035] A marking unit for subsequently marking the phase where the abnormal waveform is located with reference to the excitation waveform to determine the start and end positions and the length of the abnormal signal; and

[0036] An excision unit for finally excising the abnormal signal part.

[0037] Furthermore, the comprehensive control module further includes:

[0038] An excitation module control unit for generating an oscillation square wave signal for the excitation module, restricting the excitation signal frequency of the excitation module, and providing a reference excitation signal;

[0039] A magnetic induction intensity measurement value calculation unit for receiving the induction signal processed by the waveform feature classification anti-interference module, and obtaining the current magnetic induction intensity measurement value by performing digital signal processing on the induction signal within the sampling window;

[0040] A feedback magnetic induction intensity control unit for adding the current magnetic induction intensity measurement value to the magnetic induction intensity value of the feedback magnetic field at the previous moment to obtain the current true magnetic induction intensity value, and then using the current true magnetic induction intensity value to guide the feedback module to output a feedback current;

[0041] A data processing and output unit for adding a time stamp to the current true magnetic induction intensity value, forming a data file and outputting it; and:

[0042] Other logic control functions necessary for normal operation.

[0043] To achieve the above object, the present invention also provides the following technical solutions:

[0044] A computer device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of the method described in any one of the above are implemented.

[0045] To achieve the above object, the present invention also provides the following technical solutions:

[0046] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any one of the above are implemented.

[0047] Compared with the prior art, the beneficial effects of the present invention are:

[0048] The present invention aims at the technical problem that when a fluxgate magnetometer works in a disturbed environment, it is easily interfered by electromagnetic waves with frequencies close to the working frequency and sudden pulsed magnetic fields, resulting in the destruction of the stability of the measurement system and the deterioration of the validity of the measurement value. The disturbed environment includes but is not limited to: 1. Magnetic field navigation and magnetic field measurement carried by multi-rotor drones or vehicles; 2. Industrial magnetic field monitoring; 3. Magnetic field measurement carried by micro-miniature non-extendable rod artificial satellites, etc.

[0049] Compared with the existing anti-interference schemes for fluxgate magnetometers, the method described in this invention is based on the analysis of the physical characteristics of the fluxgate probe, and distinguishes the signal validity through the method of characteristic space vector distance, so it is more accurate and reliable. In addition, this scheme is an implementation scheme at the hardware level, with the characteristics of real-time and fast speed.

[0050] Traditional fluxgate magnetometers are usually used in scientific and exploration work. These application scenarios usually have sufficient budgets and can provide excellent magnetically clean working environments. The scheme described in this invention can expand the application scenarios of fluxgate magnetometers and enable them to work in environments with stronger interference compared to traditional application scenarios. Brief Description of the Drawings

[0051] Figure 1 It is a schematic diagram of the measurement system of an existing closed-loop mode fluxgate magnetometer.

[0052] Figure 2 It is a schematic diagram of the main functions of the integrated control module in a general fluxgate magnetometer measurement system.

[0053] Figure 3 It is a schematic diagram of the main functions of the integrated control module with a waveform feature classification anti-interference module provided by this invention.

[0054] Figure 4 It is a flowchart of the working process of the fluxgate magnetometer with a waveform feature classification anti-interference system provided by this invention.

[0055] Figure 5 It is a normal waveform diagram of the second harmonic.

[0056] Figure 6 It is a schematic diagram of an abnormal waveform segment with a 20-microsecond pulse interference applied.

[0057] Figure 7 It is a schematic diagram of an abnormal waveform segment with a 20-kHz sine wave interference signal applied.

[0058] Figure 8 It is a schematic diagram of the process of the fluxgate anti-interference method based on waveform feature classification provided by this invention.

[0059] Figure 9 It is a block diagram of the fluxgate anti-interference module based on waveform feature classification provided by this invention.

[0060] Figure 10 It is a block diagram of the integrated control module provided by this invention.

[0061] Figure 11 It is an internal structure diagram of the computer device provided by this invention. Detailed Description of the Invention

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0063] Please refer to Figures 1-11 , the present invention provides a technical solution:

[0064] A fluxgate anti-interference method based on waveform feature classification, which is applied to a fluxgate magnetometer and is used to enhance the anti-interference performance of the fluxgate magnetometer.

[0065] The basic principle of the method of the present invention is to judge the validity of the current stage data segment by observing the existence and severity of the abnormal signal features superimposed on the morphological features of the output signal of the normal fluxgate probe of the current signal. When the abnormal signal exists and exceeds the judgment threshold, this segment will be removed during the data calculation process to ensure the stability of the measurement system and the validity of the measurement data.

[0066] The implementation solution referred to in the present invention is to add a set of data morphology judgment modules on the basis of the induction module in the five modules of the original fluxgate magnetometer measurement system. This morphology judgment module stores a variety of different modes, corresponding to the normal waveform morphology models of different measurement values, and makes real-time judgments through the feature distance standard classification. Based on the judgment result, the abnormal signal is cut off. Each data point of the output data is averaged from the valid data within a sampling window. If the amount of data point excision exceeds the length of the sampling window, the data point is set to empty (NaN); when the amount of data point excision is less than the sampling window, the data point is averaged from the remaining valid data.

[0067] The closed-loop feedback fluxgate actually refers to a state in which the magnetic field measured by the induction coil is converted and a direct current magnetic field is generated through a direct current in the feedback coil to cancel it out, so that the probe always works in an environment close to "0" magnetic field. In this process, the excitation coil only provides the environment required for the probe to work (i.e., an alternating magnetic field) and does not participate in the feedback work.

[0068] As Figure 1 shown, the block diagram of a general closed-loop fluxgate magnetometer measurement system. The measurement system is as described in the background introduction, including a probe, an excitation module, an induction module, a feedback module, and a comprehensive control module. The signal flow diagram is marked by the arrow direction.

[0069] As Figure 2As shown in the figure, it is the main functional block diagram of a general closed-loop fluxgate integrated control module. The integrated control module needs to regulate the operation of the excitation module, induction module, and feedback module, and simultaneously process their input / output signal flows. The integrated control module controls the excitation module to output an excitation signal with the required frequency. The signal of the induction module refers to the phase of the excitation signal, and the induction signal within the sampling window is processed by digital signal processing to obtain the current magnetic induction intensity. The current magnetic induction intensity is added to the feedback magnetic induction intensity to obtain the current measured value of the external magnetic induction intensity. The current measured value of the magnetic induction intensity is used as a new feedback signal to guide the feedback module to output a feedback current signal. The current measured value of the magnetic induction intensity is output after post-processing such as timestamping and compression.

[0070] As Figure 3 shown in the figure, it is the main function of the integrated control module with a waveform feature classification anti-interference module. On the original basis, a waveform feature classification anti-interference module is embedded in the integrated control module. This module receives the induction signal, compares the waveform features with the waveform feature database in real time, and selects abnormal waveforms; then marks the phase where the abnormal waveform is located with reference to the excitation waveform, determines the start and end positions and length of the abnormal signal; finally, cuts off the abnormal signal part. The cut induction signal continues to participate in the conventional magnetic field information calculation to obtain the current measured value of the magnetic induction intensity. However, if the abnormal signal in the previous step exceeds the sampling window length, an empty (NaN) value is output. The current measured value of the magnetic induction intensity is used as a new feedback magnetic induction signal, but if the current measured value of the magnetic induction intensity is empty, the feedback signal of the previous moment is maintained. The current measured value of the magnetic induction intensity is output after post-processing such as timestamping and compression.

[0071] As Figure 4 shown in the figure, it is the working flow chart of the waveform feature classification anti-interference system. It briefly describes the working process of the waveform feature classification anti-interference module.

[0072] As Figure 5 shown in the figure, it is the normal waveform form segment described in the present invention.

[0073] As Figure 6 shown in the figure, it is an abnormal waveform form segment described in the present invention. It is caused by pulse interference.

[0074] As Figure 7 shown in the figure, it is another abnormal waveform form segment described in the present invention. It is caused by a sine wave interference close to the second harmonic frequency.

[0075] Specifically, the solution of the present invention is to add a sub-module for identifying the second harmonic form in the integrated control module of the fluxgate magnetometer.

[0076] During the normal operation of a parallel fluxgate magnetometer, the waveform on its induction coil theoretically comes entirely from the even - numbered waveform formed by the fluxgate effect and has unique morphological characteristics. Based on this morphological characteristic, the feature vectors of the induction waveform are extracted to establish a feature library. By calculating the distance in the feature space, the measurement signal segments severely disturbed can be identified, and then the interference can be removed and the measurement value can be corrected.

[0077] Specifically, within the range limit, the waveform of the second - harmonic is similar to Figure 5 . Note that the waveform is similar to a positive pulse followed by a negative pulse, and then remains in a nearly '0' flat state for a period of time. The heights of the positive and negative pulses are related to the external magnetic induction intensity.

[0078] Within the range limit, the morphological characteristics of the waveform disturbed by a pulse signal are similar to Figure 6 . Note that the most different part of the morphology is that the flat part is no longer flat. This morphological difference is introduced by the high - frequency magnetic - field interference at the rising and falling edges of the pulse through the parasitic detection - coil effect. In this case, the present invention uses the morphological characteristics of the flat part as a criterion.

[0079] Within the range limit, the morphological characteristics of the waveform disturbed by a quasi - sine - wave interference close to 20 kHz are similar to Figure 7 . As can be seen from the figure, this sine - wave interference signal will seriously affect the band - pass filtering and phase - sensitive detection of the induction signal. Note that the most different part of the morphology is also the flat part. In this case, the morphological characteristics of the flat part can also be used as a criterion.

[0080] The disturbed waveform may have other morphologies, including but not limited to the above two abnormal morphologies.

[0081] Based on the standard waveform morphology in a clean magnetic environment in the laboratory, the feature vectors of the standard normal waveform morphology are established. An algorithm is established to calculate in real - time the distance in the feature space between the morphological feature vectors of the input induction waveform and the feature vectors of the standard normal waveform morphology. According to the waveform morphology in a general measurement environment, the judgment threshold of the distance in the feature space between the feature vectors of the general normal waveform morphology and the feature vectors of the standard normal waveform morphology is determined. In an interference environment, once the distance in the feature space between the morphological feature vectors of the induction waveform and the feature vectors of the standard normal waveform morphology exceeds the threshold, it is considered that an abnormal waveform morphology is found.

[0082] The determination of the threshold value will be decided according to the specific application scenario and the error tolerance range, which is not within the protection scope of the present invention. The calculation process of obtaining the feature space distance between the two morphological feature vectors is a common method in machine learning methods. Specifically, it is to find the difference between the two vectors and then find the modulus length. This specific process of obtaining the feature space distance is not within the protection scope of the present invention. Distinguishing the categories of the feature vectors according to the distance between the two morphological feature vectors is a classification method in machine learning methods. This classification method is not within the protection scope of the present invention.

[0083] When the fluxgate magnetometer is working normally, there is a fixed phase difference between the positive and negative pulse peaks of the second-harmonic waveform morphology and the input square wave of the excitation module (hereinafter referred to as the excitation square wave). Therefore, the phase of the second harmonic can be marked by referring to the excitation waveform.

[0084] After an abnormal waveform morphology is found, the abnormal flag bit in the comprehensive controller is suspended, and the starting phase of the abnormal waveform is marked. Continue to monitor the waveform morphology until the interference ends and the abnormal waveform morphology disappears. Subsequently, the comprehensive controller marks the ending phase of the abnormal waveform, and the abnormal flag bit is released.

[0085] When the abnormal flag bit is suspended, the induction signal does not participate in the calculation of the magnetic induction intensity. That is, the signals between the starting phase of the abnormal waveform and the ending phase of the abnormal waveform will be discarded.

[0086] The fluxgate magnetometer usually focuses on low-frequency magnetic field fluctuations. Taking a fluxgate magnetometer with an excitation frequency of 10 kHz as an example, generally, an observation window of 0.01 seconds is used. All the induction signals within this window are jointly calculated to obtain a magnetic induction intensity data point, that is, downsampled from 10 kHz to 100 Hz.

[0087] If all the induction signals within an observation window are discarded, that is, no induction signal participates in the calculation, then the output magnetic induction intensity data point corresponding to this window is marked as empty (NaN).

[0088] When the output magnetic induction intensity data point is empty, the comprehensive control module controls the feedback module to keep the previous feedback value unchanged.

[0089] The above method is stored in a computer-readable storage medium in the form of an executable program and is executed by the comprehensive control module of the fluxgate magnetometer. The comprehensive control module can be an embedded processor such as an FPGA / CPLD or an ARM single-chip microcomputer.

[0090] In the present invention, a computer device may include a memory, a storage controller, one or more processors (only one is shown in the figure), etc. Each component is electrically connected directly or indirectly to achieve data transmission or interaction. For example, these components may be electrically connected through one or more communication buses or signal buses. The fluxgate anti-interference method based on waveform feature classification respectively includes at least one software function module that can be stored in the memory in the form of software or firmware, such as the software function module or computer program included in the fluxgate anti-interference device based on waveform feature classification. The memory can store various software programs and modules, such as the program instructions / modules corresponding to the fluxgate anti-interference method and device provided in the embodiments of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, the parsing method in the embodiments of the present application is implemented.

[0091] The present invention aims at the technical problem that when a fluxgate magnetometer works in a disturbed environment, it is easily interfered by electromagnetic waves with a working frequency close to it and sudden pulsed magnetic fields, resulting in the destruction of the stability of the measurement system and the deterioration of the validity of the measurement value. The disturbed environment includes but is not limited to: 1. Magnetic field navigation and magnetic field measurement carried by multi-rotor unmanned aerial vehicles or vehicles; 2. Industrial magnetic field monitoring; 3. Magnetic field measurement carried by micro-miniature non-extendable rod artificial satellites, etc.

[0092] Compared with the existing fluxgate magnetometer anti-interference solutions, the method described in this invention is based on the analysis of the physical characteristics of the fluxgate probe, and distinguishes the signal validity through the method of feature space vector distance, so it is more accurate and reliable. In addition, this solution is an implementation solution at the hardware level and has the characteristics of real-time and fast.

[0093] Traditional fluxgate magnetometers are usually used in scientific and exploration work, and these application scenarios usually have sufficient budgets to provide excellent magnetically clean working environments. The solution described in the present invention can expand the application scenarios of fluxgate magnetometers, enabling them to work in environments with stronger interference compared to traditional application scenarios.

[0094] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fluxgate anti-interference method based on waveform feature classification, characterized in that, Comprising: Exciting a probe with an excitation signal outputting a required frequency; Obtaining an induced signal of the probe with reference to the phase of a reference excitation signal; Obtaining a current magnetic induction intensity by subjecting the induced signal within a sampling window to digital signal processing; Capturing the induced signal, identifying the signal form, marking an abnormal phase, and then excising the abnormal signal; Performing magnetic field data calculation on the induced signal with the abnormal signal excised to obtain a current magnetic induction intensity measurement value; Outputting the data after processing the current magnetic induction intensity measurement value; The capturing the induced signal, identifying the signal form, marking an abnormal phase, and then excising the abnormal signal comprises: Receiving the induced signal, comparing the waveform feature database in real time, and selecting an abnormal waveform; Subsequently, marking the phase where the abnormal waveform is located with reference to the excitation waveform, and determining the start position, end position and length of the abnormal signal; Finally, excising the abnormal signal part; The current window magnetic induction intensity measurement value is obtained by calculating with the remaining normal signals after excising the abnormal signal; the current window magnetic induction intensity measurement value serves as a new feedback magnetic induction intensity signal of the fluxgate probe; if the abnormal signal exceeds the sampling window length, the current window magnetic induction measurement value is output as empty; the current magnetic induction intensity measurement value serves as a new feedback magnetic induction signal of the excitation probe, is converted into a feedback current, and fed back to the probe; if the current magnetic induction intensity measurement value is empty, the feedback signal of the previous moment is maintained; the current magnetic induction intensity measurement value is output after being timestamped, compressed and processed; Extracting the feature vector of the induced waveform from the even waveform formed by the fluxgate effect of the probe, establishing a feature library, calculating in real time the feature space distance between the form feature vector of the input induced waveform and the form feature vector of the standard normal waveform, and establishing a judgment threshold for the feature space distance between the form feature vector of the normal waveform and the form feature vector of the standard normal waveform according to the waveform form in the measurement environment. In an interference environment, once the feature space distance between the form feature vector of the induced waveform and the form feature vector of the standard normal waveform exceeds the threshold, it is considered that an abnormal waveform form is found.

2. The method according to claim 1, characterized in that, After finding an abnormal waveform form, the abnormal flag bit is suspended, the starting phase of the abnormal waveform is marked, and the waveform form is continuously monitored until the interference ends and the abnormal waveform form disappears. Subsequently, the ending phase of the abnormal waveform is marked and the abnormal flag bit is released.

3. A fluxgate anti-interference device based on waveform feature classification according to the method described in claim 1 or 2, characterized in that, Comprising: An integrated control module, including a magnetic induction intensity measurement value calculation unit; An excitation module for exciting a probe with an excitation signal outputting a required frequency; An induction module for obtaining an induced signal of the probe with reference to the phase of a reference excitation signal; A magnetic induction intensity measurement value calculation unit for obtaining a current magnetic induction intensity by subjecting the induced signal within a sampling window to digital signal processing; A waveform feature classification anti-interference module for receiving the induced signal, identifying the signal form, marking an abnormal phase, and then excising the abnormal signal; An integrated control module for performing magnetic field data calculation on the induced signal with the abnormal signal excised to obtain a current magnetic induction intensity measurement value; and for outputting the data after processing the current magnetic induction intensity measurement value.

4. The device according to claim 3, wherein, It further includes a feedback module, which is used to output a quasi-direct-current feedback current signal, generate a feedback magnetic field on the probe, and maintain the probe to work within the required magnetic field dynamic range.

5. The device according to claim 3, wherein The waveform feature classification anti-interference module includes: An identification unit, which is used to receive the induction signal, compare it with the waveform feature database in real time, and select abnormal waveforms; A marking unit, which is used to subsequently mark the phase where the abnormal waveform is located with reference to the excitation waveform, and determine the start and end positions and the length of the abnormal signal; and An excision unit, which is used to finally excise the abnormal signal part.

6. The device according to claim 4, wherein The comprehensive control module includes: An excitation module control unit, which is used to give the starting square wave signal of the excitation module, limit the excitation signal frequency of the excitation module, and give a reference excitation signal; A feedback magnetic induction intensity control unit, which is used to add the current magnetic induction intensity measurement value and the magnetic induction intensity value of the feedback magnetic field at the previous moment to obtain the current true magnetic induction intensity value, and then use the current true magnetic induction intensity value to guide the feedback module to output a feedback current; A data processing and output unit, which is used to add a time stamp to the current true magnetic induction intensity value, form a data file and output it.

7. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 2.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method according to any one of claims 1 to 2.

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