CN114690084A

CN114690084A - Anti-interference method and device for fluxgate based on waveform feature classification

Info

Publication number: CN114690084A
Application number: CN202210156756.XA
Authority: CN
Inventors: 袁恺鑫; 张魁祥; 杜爱民; 赵琳; 孙树全; 李智; 冯晓
Original assignee: Institute of Geology and Geophysics of CAS
Current assignee: Institute of Geology and Geophysics of CAS
Priority date: 2022-02-21
Filing date: 2022-02-21
Publication date: 2022-07-01

Abstract

The invention relates to the field of magnetic variable measurement, in particular to a fluxgate anti-interference method and a device based on waveform feature classification, which comprises the following steps: outputting an excitation signal with a required frequency to excite the probe; acquiring an induction signal of the probe by referring to the phase of the excitation signal, and processing the induction signal in the sampling window by a digital signal to obtain the current magnetic induction intensity; receiving an induction signal, identifying the signal form, marking an abnormal phase, and then cutting off the abnormal signal; performing magnetic field data resolving on the induction signal with the abnormal signal removed to obtain a current magnetic induction intensity measurement value; and outputting data after processing the current magnetic induction intensity measurement value. The invention distinguishes the signal effectiveness by a characteristic space vector distance classification method based on the analysis of the physical characteristics of the fluxgate probe, thereby being more accurate and reliable and having the characteristics of real time and rapidness.

Description

Anti-interference method and device for fluxgate based on waveform feature classification

Technical Field

The invention relates to the technical field of magnetic variable measurement, in particular to a fluxgate anti-interference method and device based on waveform feature classification.

Background

The fluxgate magnetometer is a main instrument for measuring a magnetic field and can measure a three-component space vector magnetic field. The fluxgate magnetometer has the advantages of low power consumption, small volume, high precision, good reliability and the like, and is widely applied to the fields of aviation, aerospace and foundation magnetic field measurement at present. The fluxgate magnetometer converts low-frequency magnetic field signals in a space into electric signals by virtue of the fluxgate effect of the soft magnetic core through the exciting coil and the induction coil. In order to improve the accuracy of the fluxgate magnetometer in measuring the spatial magnetic field, the induction coil of the fluxgate magnetometer generally has very high sensitivity so as to realize precise detection of the external magnetic field. At the same time, however, high frequency electromagnetic signals are picked up by the high sensitivity induction coil. If the frequency of the high-frequency electromagnetic wave signal is close to the excitation frequency of the fluxgate magnetometer, the high-frequency electromagnetic wave signal greatly interferes the measurement data of the fluxgate.

Generally, a fluxgate magnetometer for closed-loop measurements comprises five main modules, respectively: the flux gate probe, the excitation module, the induction module, the feedback module and the comprehensive control module. The comprehensive control module controls the excitation module to generate an excitation signal; the excitation signal excites a symmetrical alternating magnetic field on an excitation coil of the fluxgate probe to periodically saturate a magnetic core of the probe; the periodic saturated magnetic field of the magnetic core is superposed with an external magnetic field to be measured, and an asymmetric alternating current signal with information of the magnetic field to be measured is generated on the induction coil and is called as an induction signal; the induction module picks up the induction signal, and a series of preprocessing are carried out to extract the external magnetic field information to be detected; the comprehensive control module performs post-processing on the magnetic field information to be measured, outputs data and guides the feedback module to perform feedback; the feedback module generates a feedback signal, and a quasi-direct current feedback signal is formed on a feedback coil of the probe to offset the magnetic field intensity of the space where the probe is located. This process is known as closed loop control of the fluxgate magnetometer. The magnetic induction actually measured by the closed-loop fluxgate magnetometer should be the sum of the magnetic induction measured by the induction module and the feedback magnetic induction of the feedback module.

The work of the fluxgate probe is based on the fluxgate effect and is mainly used for measuring a low-frequency magnetic field. Taking a conventional circular magnetic core parallel fluxgate magnetometer with a 10kHz excitation frequency as an example, the second harmonic of the induction coil, i.e. the induced current signal of 20kHz, will carry 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.

The fluxgate probe itself has a similar structure to a search coil magnetometer which is sensitive to high frequency signals. The search coil magnetometer is sensitive to high frequency magnetic field fluctuations, which will therefore be sensed by such parasitic search coils.

In actual operation, ultralow frequency magnetic field fluctuation which flows in a collimation mode to be lower than 100Hz is captured by the fluxgate effect, generally regarded as an effective magnetic field signal to be detected, and extracted by the fluxgate magnetometer. The magnetic field fluctuation higher than 100Hz and lower than 1kHz can be captured by the fluxgate effect, but is filtered out by the integrated control module of the magnetometer in a digital low-pass filtering mode. Magnetic field fluctuations above the order of 50kHz are not captured by the fluxgate effect but are sensed by the structure described above for a similar search coil magnetometer, and these signals are filtered out by hardware analog low pass filtering of the magnetometer sensing module. But magnetic field fluctuation signals close to the excitation waveform (10 kHz) and the second harmonic (20 kHz), namely, the frequency of about 5 kHz-30 kHz, comprise pulses, sine waves and the like, the frequency range is the range concerned by the instrument, and digital and analog filtering means cannot eliminate the frequency range. The measurement data of the fluxgate magnetometer will be directly destroyed by a strong disturbance with a characteristic frequency close to around 20 kHz.

Generally, in scientific research and surveying and mapping work, the flux gate magnetometer probe is often kept as far away from interference as possible. For example, it is mounted on a magnetic cleaning boom away from the interference by several meters to several tens of meters, or is installed in a magnetic cleaning room without an electromagnetic interference source to avoid the interference.

At present, the application demand of precision magnetic field measurement is continuously increased in the fields of industrial production, medical inspection and internet of things. In these environments, if it is desired to apply a fluxgate magnetometer, perfect magnetic cleaning measures similar to those in scientific research and surveying and mapping activities cannot be achieved due to cost control and complicated working condition requirements. The anti-interference capability of the fluxgate magnetometer applied to these fields needs to be improved urgently.

The waveform of the induction signal of the normally working fluxgate has the expected morphological characteristics. If the fluxgate magnetometer is strongly disturbed, its actual morphological characteristics deviate from the expected morphological characteristics. In the related art of machine learning, morphological features are typically generalized as vectors in feature space, and the difference between two morphological features can be expressed as a modulus of the difference between the corresponding two vectors in feature space.

Disclosure of Invention

The invention aims to provide a fluxgate anti-interference method and device based on waveform feature classification, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a fluxgate anti-interference method based on waveform feature classification comprises the following steps:

s110, outputting an excitation signal with a required frequency to excite a probe;

s120, acquiring an induction signal of the probe by referring to the phase of the excitation signal;

s130, processing the induction signal in the sampling window through a digital signal to obtain the current magnetic induction intensity;

s140, capturing the induction signals, identifying the signal form, marking an abnormal phase, and then cutting off the abnormal signals;

s150, performing magnetic field data calculation on the induction signals of the removed abnormal signals to obtain a current magnetic induction intensity measured value;

and S160, outputting data after processing the current magnetic induction intensity measurement value.

Further, the receiving the sensing signal, identifying the signal form, labeling the abnormal phase, and then cutting off the abnormal signal includes:

comparing the received induction signals with a waveform characteristic database in real time, and selecting abnormal waveforms;

then, the phase position of the abnormal waveform is marked by referring to the excitation waveform, and the starting and stopping positions and the length of the abnormal signal are determined;

finally, the abnormal signal part is cut off.

Further, after the abnormal signal is cut off, the current window magnetic induction measurement value is obtained by resolving through the rest normal signals; taking the current window magnetic induction measurement value as a new feedback magnetic induction signal of the fluxgate probe; if the abnormal signal exceeds the length of the sampling window, outputting a current window magnetic induction measured value to be null; the current magnetic induction intensity measured value is used as a new feedback magnetic induction signal for exciting the probe, converted into feedback current and fed back to the probe through the feedback module; if the current magnetic induction intensity measurement value is empty, maintaining the feedback signal at the previous moment; and the current magnetic induction intensity measurement value is output after being subjected to time stamping and compression post-processing.

Further, extracting a feature vector of the induction waveform according to an even waveform formed by the fluxgate effect of the probe, establishing a feature library, calculating a feature space distance between a form feature vector of the input induction waveform and a form feature vector of a standard normal waveform in real time, determining a judgment threshold of 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 a waveform form under a measurement environment, and considering that an abnormal waveform form is found once the feature space distance between the form feature vector of the induction waveform and the form feature vector of the standard normal waveform exceeds the threshold under an interference environment.

Further, after the abnormal waveform form is found, the abnormal zone bit is suspended, the initial phase of the abnormal waveform is marked, the waveform form is continuously monitored until the interference is finished, the abnormal waveform form disappears, then the ending phase of the abnormal waveform is marked, and the abnormal zone bit is released.

In order to achieve the above purpose, the invention also provides the following technical scheme:

a fluxgate anti-jamming device based on waveform feature classification comprises:

the excitation module is used for outputting an excitation signal with required frequency to excite the probe;

the sensing module is used for obtaining a sensing signal of the probe by referring to the phase of the excitation signal;

the waveform characteristic classification anti-interference module is used for receiving the induction signals, identifying the signal form, marking an abnormal phase and then cutting off the abnormal signals;

the comprehensive control module is used for resolving magnetic field data of the induction signal of the removed abnormal signal to obtain a current magnetic induction intensity measured value; and the magnetic induction intensity measuring device is used for outputting data after processing the current magnetic induction intensity measuring value; specifically, the comprehensive control module is used for controlling the normal work of all the modules and packaging and outputting the current real magnetic induction intensity value data.

Further, the feedback module is used for outputting a quasi-direct current feedback current signal, generating a feedback magnetic field on the probe and maintaining the probe to work in a required (smaller) dynamic range of the magnetic field.

Further, the waveform feature classification anti-interference module comprises:

the identification unit is used for comparing the received induction signals with a waveform characteristic database in real time and selecting abnormal waveforms;

the marking unit is used for marking the phase of the abnormal waveform by referring to the excitation waveform and determining the starting and stopping positions and the length of the abnormal signal; and

and a cutting unit for cutting off the abnormal signal portion at last.

Further, the integrated control module further comprises:

the excitation module control unit is used for giving an oscillation starting square wave signal of the excitation module, limiting the frequency of an excitation signal of the excitation module and giving a reference excitation signal;

the magnetic induction intensity measurement value calculation unit is used for receiving the induction signals processed by the waveform characteristic classification anti-interference module and processing the induction signals in the sampling window by digital signals to obtain a current magnetic induction intensity measurement value;

the feedback magnetic induction control unit is used for summing the current magnetic induction measured value and the magnetic induction intensity value of the feedback magnetic field at the previous moment to obtain a current real magnetic induction intensity value, and then guiding the feedback module to output feedback current by using the current real magnetic induction intensity value;

the data processing and outputting unit is used for adding a time stamp to the current real magnetic induction intensity value to form a data file and outputting the data file; and:

other logic control functions necessary for proper operation.

a computer device comprising a memory storing a computer program and a processor implementing the steps of the method as claimed in any one of the above when the computer program is executed.

a computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of the preceding claims.

Compared with the prior art, the invention has the beneficial effects that:

the invention aims to solve the technical problems that when the fluxgate magnetometer works in a disturbance environment, the fluxgate magnetometer is easily interfered by electromagnetic waves with similar working frequency and a sudden pulse magnetic field, so that the stability of a measuring system is damaged, and the effectiveness of a measured value is deteriorated. The disturbance environment includes but is not limited to: 1. magnetic field navigation and magnetic field measurement carried by a multi-rotor unmanned aerial vehicle or a vehicle; 2. monitoring an industrial magnetic field; 3. magnetic field measurement carried by a microminiature non-extension-rod artificial satellite, and the like.

Compared with the existing anti-interference scheme of the fluxgate magnetometer, the method is more accurate and reliable because the signal effectiveness is distinguished by the method of the characteristic space vector distance based on the analysis of the physical characteristics of the fluxgate probe. In addition, the scheme is a hardware level implementation scheme and has the characteristics of real time and high speed.

The traditional fluxgate magnetometer is usually used for scientific and exploration work, and the application scenes are usually sufficient in budget and can provide an excellent magnetic clean working environment. The scheme described by the invention can expand the application scene of the fluxgate magnetometer, so that the fluxgate magnetometer works in an environment with stronger interference compared with the traditional application scene.

Drawings

Fig. 1 is a schematic view of a conventional closed-loop mode fluxgate magnetometer measurement system.

Fig. 2 is a schematic diagram of main functions of an integrated control module in a general fluxgate magnetometer measurement system.

FIG. 3 is a schematic diagram of the main functions of the integrated control module with the waveform feature classification anti-jamming module provided by the present invention.

Fig. 4 is a flow chart of the working process of the fluxgate magnetometer with the waveform feature classification anti-interference system provided by the present invention.

Fig. 5 is a diagram of a second harmonic normal waveform.

FIG. 6 is a schematic diagram of an abnormal waveform segment with a 20 microsecond pulsed glitch applied.

FIG. 7 is a schematic diagram of an abnormal waveform segment for applying a 20kHz sine wave interference signal.

Fig. 8 is a schematic flow chart of a fluxgate anti-interference method based on waveform feature classification according to the present invention.

Fig. 9 is a block diagram of a fluxgate anti-jamming module based on waveform feature classification according to the present invention.

FIG. 10 is a block diagram of the integrated control module of the present invention.

Fig. 11 is an internal structural view of the computer device of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-11, the present invention provides a technical solution:

a fluxgate anti-interference method based on waveform feature classification is applied to a fluxgate magnetometer and used for enhancing the anti-interference performance of the fluxgate magnetometer.

The basic principle of the method is that the validity of the data segment in the current phase is judged by observing the existence and the severity of the superposed abnormal signal characteristics of the current signal on the morphological characteristics of the normal output signal of the fluxgate probe. When the abnormal signal exists and exceeds a judgment threshold value, the segment is removed in the data resolving process so as to ensure the stability of the measuring system and the validity of the measuring data.

The implementation scheme of the invention is that a group of data form judgment modules are added on the basis of the induction module in five modules of the original fluxgate magnetometer measurement system. The form judging module stores a plurality of different modes, corresponds to normal waveform form models of different measured values and carries out real-time judgment through characteristic distance standard classification. Based on the determination result, the abnormal signal is cut off. The output data is averaged for each data point from the valid data within a sampling window. If the data point resection exceeds the sampling window length, the data point is set to null (NaN); when the corresponding data point cut-off is smaller than the sampling window, the data point is averaged from the remaining valid data.

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

As shown in fig. 1, a block diagram of a typical closed-loop fluxgate magnetometer measurement system. The measurement system, as explained in the background introduction, includes a probe, an excitation module, a sensing module, a feedback module, and a comprehensive control module. Indicated by the direction of the arrows in the signal flow diagram.

As shown in fig. 2, a main functional block diagram of a general closed-loop fluxgate integrated control module. The comprehensive control module needs to regulate and control the work of the excitation module, the induction module and the feedback module and simultaneously process the input/output signal flow of the excitation module, the induction module and the feedback module. The comprehensive control module controls the excitation module to output an excitation signal with required frequency. And the signal of the induction module refers to the phase of the excitation signal, and the induction signal in the sampling window is processed by a digital signal to obtain the current magnetic induction intensity. And adding the current magnetic induction intensity and the feedback magnetic induction intensity to obtain a current external magnetic induction intensity measured value. And the current magnetic induction intensity measured value is used as a new feedback signal to guide the feedback module to output a feedback current signal. And the current magnetic induction intensity measurement value is output after post-processing such as time stamping, compression and the like.

As shown in fig. 3, the main functions of the integrated control module with the waveform feature classification immunity module. On the original basis, a waveform characteristic classification anti-interference module is embedded in the comprehensive control module. The module receives the induction signal, compares the induction signal with a waveform characteristic database in real time and selects an abnormal waveform; then, the phase position of the abnormal waveform is marked by referring to the excitation waveform, and the starting and stopping positions and the length of the abnormal signal are determined; finally, the abnormal signal part is cut off. The cut induction signals continuously participate in conventional magnetic field information calculation to obtain the current magnetic induction intensity measurement value. But outputs a null (NaN) if the previous step exception signal exceeds the sampling window length. The current magnetic induction measurement value is used as a new feedback magnetic induction signal, but if the current magnetic induction measurement value is empty, the feedback signal at the previous moment is maintained. And the current magnetic induction intensity measurement value is output after post-processing such as time stamping, compression and the like.

As shown in fig. 4, the waveform feature classification anti-jamming system work flow chart. The working process of the waveform characteristic classification anti-interference module is briefly described.

As shown in FIG. 5, the normal waveform morphology segments described in the present invention.

Referring to fig. 6, an abnormal waveform shape segment according to the present invention is shown. Caused by impulse interference.

Referring to fig. 7, another abnormal waveform shape segment is shown. Caused by sinusoidal interference near the second harmonic frequency.

Specifically, the scheme of the invention is that a submodule for identifying the second harmonic wave form is added in a comprehensive control module of the fluxgate magnetometer.

In the normal working process of the parallel fluxgate magnetometer, the waveform on the induction coil of the parallel fluxgate magnetometer is theoretically completely from the even-order waveform formed by the fluxgate effect, and has unique morphological characteristics. According to the morphological characteristics, the characteristic vector of the induction waveform is extracted, a characteristic library is established, and the measuring signal segment suffering from serious interference can be identified by a method of solving the characteristic space distance, so that the interference is removed, and the measured value is corrected.

Specifically, the waveform shape of the second harmonic without exceeding the span is similar to that of fig. 5. Note that the waveform morphology resembles a positive pulse followed by a negative pulse followed by a gradual morphology of near '0' for a period of time. The height of the positive and negative pulses is related to the external magnetic induction intensity.

Without exceeding the range, the waveform morphology characteristics encountered with pulsed signal interference are similar to fig. 6. Note that the portion where the morphological difference is the largest, that is, the gentle portion, is not gentle any more. This morphological difference is introduced via parasitic detection coil effects due to high frequency magnetic field interference at the leading and trailing edges of the pulse. For the situation, the invention takes the morphological characteristics of the gentle part as the criterion.

The waveform morphology characteristics of a sine wave like interference encountering near 20kHz without exceeding span are similar to those of fig. 7. As can be seen, such a sinusoidal disturbance signal will severely affect the band-pass filtering and phase sensitive detection of the induced signal. Note that the portion where the morphological difference is the largest is also the gentle portion. For this case, the morphological feature of the gentle portion may be used as a criterion.

The disturbed waveform may have other configurations including, but not limited to, the two anomalous configurations described above.

And establishing a characteristic vector of a standard normal waveform form according to the standard waveform form in the clean magnetic environment of the laboratory. And establishing an algorithm, and calculating the characteristic space distance between the input sensing waveform morphological characteristic vector and the standard normal waveform morphological characteristic vector in real time. According to the waveform form under the general measurement environment, a judgment threshold value of the characteristic space distance between the general normal waveform form feature vector and the standard normal waveform form feature vector is established. Under the interference environment, the abnormal waveform is considered to be found once the characteristic space distance between the form characteristic vector of the induction waveform and the form characteristic vector of the standard normal waveform exceeds a threshold value.

The threshold value determination will be determined according to the specific application scenario and the error tolerance range, and is not within the protection scope of the present invention. The calculation process of calculating the feature space distance by the two morphological feature vectors is a common method in a machine learning method, and is specifically represented by calculating the difference of the two vectors and then calculating the modular length, and the specific process of calculating the feature space distance is out of the protection scope of the invention. The classification of feature vectors according to the distance between two morphological feature vectors is a classification method in machine learning methods, and this classification method is not within the scope of the present invention.

Under the condition that the fluxgate magnetometer normally works, the positive and negative pulse spikes of the second harmonic waveform form have a constant phase difference with the input square wave (hereinafter referred to as excitation square wave) of the excitation module, so that the phase of the second harmonic can be labeled by referring to the excitation waveform.

And after the abnormal waveform form is found, suspending an abnormal zone bit in the integrated controller, and marking the initial phase of the abnormal waveform. And continuing to monitor the waveform form until the interference is finished and the abnormal waveform form disappears, then marking the abnormal waveform ending phase by the integrated controller, and releasing the abnormal zone bit.

When the abnormal zone bit is suspended, the induction signal does not participate in resolving the magnetic induction intensity. That is, the signal between the abnormal waveform start phase and the abnormal waveform end phase will be discarded.

The fluxgate magnetometer usually focuses on low-frequency magnetic field fluctuation, taking the fluxgate magnetometer with an excitation frequency of 10kHz as an example, 0.01 second is generally taken as an observation window, and all induction signals in the window are jointly solved to obtain a magnetic induction data point, namely, the magnetic induction data point is subtracted from 10kHz to 100 Hz.

If all the induction signals in an observation window are discarded, i.e. no induction signal participates in the calculation, the output magnetic induction data point corresponding to the window is marked as null (NaN).

When the output magnetic induction intensity data point is empty, the comprehensive control module controls the feedback module to keep the feedback value at the last moment unchanged.

The above method is stored in a computer readable storage medium in the form of an executable program, and is executed by an integrated control module of the fluxgate magnetometer. The integrated control module can be an embedded processor such as an FPGA/CPLD or an ARM singlechip.

In the present invention, a computer device may include a memory, a storage controller, one or more processors (only one shown in the figure), and the like, and the elements are electrically connected directly or indirectly to realize the transmission or interaction of data. For example, electrical connections between these components may be made through one or more communication or signal buses. The fluxgate anti-jamming method based on the waveform feature classification respectively includes at least one software functional module which may be stored in a memory in a form of software or firmware (firmware), for example, the fluxgate anti-jamming device based on the waveform feature classification includes the software functional module or a computer program. The memory may store various software programs and modules, such as program instructions/modules corresponding to the fluxgate anti-jamming method and apparatus based on waveform feature classification provided in the embodiments of the present application. The processor executes various functional applications and data processing by running software programs and modules stored in the memory, that is, implements the parsing method in the embodiments of the present application.

Compared with the existing anti-interference scheme of the fluxgate magnetometer, the method is more accurate and reliable because the signal effectiveness is distinguished by a characteristic space vector distance method based on the analysis of the physical characteristics of the fluxgate probe. In addition, the scheme is a hardware level implementation scheme and has the characteristics of real time and high speed.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A fluxgate anti-interference method based on waveform feature classification is characterized by comprising the following steps:

outputting an excitation signal with a required frequency to excite the probe;

acquiring an induction signal of the probe by referring to the phase of the excitation signal;

processing the induction signal in the sampling window by a digital signal to obtain the current magnetic induction intensity;

capturing an induction signal, identifying the signal form, marking an abnormal phase, and then cutting off the abnormal signal;

performing magnetic field data resolving on the induction signal of the removed abnormal signal to obtain a current magnetic induction intensity measurement value;

and outputting data after processing the current magnetic induction intensity measurement value.

2. The method of claim 1, wherein receiving the sensing signal, identifying the signal morphology, and noting the abnormal phase, and then removing the abnormal signal comprises:

then, the phase of the abnormal waveform is marked by referring to the excitation waveform, and the starting and stopping positions and the length of the abnormal signal are determined;

finally, cutting off the abnormal signal part.

3. The method according to claim 2, wherein the current window magnetic induction measurement value is obtained by calculation using the remaining normal signals after the abnormal signals are removed; taking the current window magnetic induction measurement value as a new feedback magnetic induction signal of the fluxgate probe; if the abnormal signal exceeds the length of the sampling window, outputting a current window magnetic induction measured value to be null; the current magnetic induction intensity measured value is used as a new feedback magnetic induction signal for exciting the probe, converted into feedback current and fed back to the probe; if the current magnetic induction intensity measurement value is empty, maintaining the feedback signal at the previous moment; and the current magnetic induction intensity measurement value is output after being subjected to time stamping and compression post-processing.

4. The method according to claim 2, wherein the feature vector of the sensing waveform is extracted according to an even waveform formed by the fluxgate effect of the probe, a feature library is established, the feature space distance between the morphological feature vector of the input sensing waveform and the morphological feature vector of the standard normal waveform is calculated in real time, the determination threshold of the feature space distance between the morphological feature vector of the normal waveform and the morphological feature vector of the standard normal waveform is established according to the waveform shape under the measurement environment, and the abnormal waveform is considered to be found once the feature space distance between the morphological feature vector of the sensing waveform and the morphological feature vector of the standard normal waveform exceeds the threshold under the interference environment.

5. The method of claim 4, wherein after the abnormal waveform shape is found, the abnormal flag bit is suspended, the abnormal waveform starting phase is labeled, the waveform shape is monitored continuously until the disturbance is over and the abnormal waveform shape disappears, then the abnormal waveform ending phase is labeled, and the abnormal flag bit is released.

6. The utility model provides a fluxgate anti jamming unit based on wave form characteristic is categorised which characterized in that includes:

the comprehensive control module comprises a magnetic induction intensity measurement value calculation unit;

the magnetic induction intensity measurement value calculation unit is used for processing the induction signals in the sampling window through digital signals to obtain the current magnetic induction intensity;

the comprehensive control module is used for resolving magnetic field data of the induction signals with the abnormal signals removed to obtain a current magnetic induction intensity measured value; and the magnetic induction intensity measuring device is used for processing the current magnetic induction intensity measured value and then outputting the data.

7. The apparatus of claim 6,

the device also comprises a feedback module which is used for outputting a quasi-direct current feedback current signal, generating a feedback magnetic field on the probe and maintaining the probe to work in a required magnetic field dynamic range.

8. The apparatus of claim 6,

the waveform characteristic classification anti-interference module comprises:

and a cutting unit for cutting off the abnormal signal portion at last.

9. The apparatus of claim 7,

the integrated control module includes:

and the data processing and outputting unit is used for adding a time stamp to the current real magnetic induction intensity value to form a data file and outputting the data file.

10. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method according to any of claims 1 to 5.

11. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 5.