CN-121703711-B - Rotating magnet magnetic field vector interference compensation method based on self-adaptive spectrum tracking

Abstract

A rotating magnet magnetic field vector interference compensation method based on self-adaptive frequency spectrum tracking comprises the steps of establishing a reference digital model of a rotating magnetic component, obtaining an original magnetic measurement vector signal sequence of a three-component magnetic sensor at a preset observation point, constructing a time domain observation vector, establishing a limited harmonic model of each axial component, establishing a spatial modulation function, combining the limited harmonic model with the spatial modulation function to obtain a modulated time domain signal, carrying out fast Fourier transform on the modulated time domain signal, self-adaptively updating second-order IIR trap parameters under the constraint of a candidate frequency point set, carrying out inverse fast Fourier transform to obtain a noise suppression time domain magnetic field signal, obtaining a cross-rotating-speed non-stationary magnetic field signal based on the noise suppression time domain magnetic field signal, carrying out vector fusion and coordinate equalization on the non-stationary magnetic field signal, and outputting a final dynamic magnetic vector signal map after interference compensation. The invention can improve the filtering effect on noise frequency points and the interference compensation effect.

Inventors

• Li Supi
• LI ZEWEN
• XIE JIANJUN
• ZHANG YU
• ZHANG YIPING
• WU BAIQI
• YU XIAOSI
• ZENG HAN
• DENG FANGMING
• WEI BAOQUAN
• SUN MIN
• XUE XIANFA
• ZENG JIANJUN

Assignees

• 华东交通大学

Dates

Publication Date

20260508

Application Date

20260206

Claims (3)

1. 1. The method for compensating the disturbance of the magnetic field vector of the rotating magnet based on the self-adaptive frequency spectrum tracking is characterized by comprising the following steps: step S1, a reference digital model of a rotating magnetic component is established, an original magnetic measurement vector signal sequence of a three-component magnetic sensor at a preset observation point is obtained, and sectional framing and normalization are carried out according to a rotation period or a sliding window, so that a time domain observation vector for subsequent processing and steady-state mapping thereof are constructed; s2, short-time frequency spectrum tracking is carried out on the time domain observation vector so as to estimate rotation fundamental frequency and phase, and a limited harmonic model of each axial component is established under the constraint of the fundamental frequency, so that amplitude and phase parameters changing along with angular velocity are obtained; Step S3, establishing a spatial modulation function representing circumferential non-uniformity and amplitude-phase fluctuation, and generating a candidate frequency point set of a main peak and a side band according to the spatial modulation function; s4, combining the limited harmonic model with a spatial modulation function to obtain a modulated time domain signal containing a main peak-side band structure and a frequency domain expression thereof; S5, performing fast Fourier transform on the modulated time domain signal, adaptively updating parameters of a second-order IIR trap under the constraint of a candidate frequency point set, realizing on-line positioning and suppression of a main peak and a side band frequency point, and then obtaining a noise-suppressing time domain magnetic field signal through inverse fast Fourier transform; s6, performing equal-angle domain resampling and uniform time axis splicing on noise-suppressing time domain magnetic field signals of different angular velocity sections to obtain a rotating speed-crossing non-stationary magnetic field signal; Step S7, defining a fixed orthogonal rotation matrix from a rotation reference axis to a magnetic sensor axis, carrying out vector fusion and coordinate consistency on the non-stationary magnetic field signals at the trans-rotation speed, and outputting final dynamic magnetic vector signal mapping and related parameters after interference compensation; in step S1, the time domain observation vector and its steady state mapping satisfy the following formula: Wherein, the Representation of At the moment at the angular velocity of rotation The periodic steady state magnetic field vector mapping of the rotating magnet below, Is that At the moment at the angular velocity of rotation Measured by a lower magnetic sensor A sequence of axial electromagnetic signals, Is that At the moment at the angular velocity of rotation Measured by a lower magnetic sensor A sequence of axial electromagnetic signals, Is that At the moment at the angular velocity of rotation Measured by a lower magnetic sensor A sequence of axial electromagnetic signals, Representing a transpose; in step S2, the finite harmonic model of each axial component satisfies the following equation: Wherein, the Representing the axial index of the device, , Indicating the angular velocity of rotation Corresponding to A finite harmonic model of the axial component, And Respectively the first The order harmonic wave is in the axial direction The amplitude and phase of the signal at the same time, The highest order for finite harmonic expansion, Is the rotation angular velocity The corresponding fundamental frequency is used to determine the frequency, Modeling residual terms; in step S3, the spatial modulation function satisfies the following equation: Wherein, the To rotate phase angle The corresponding spatial modulation function is used to determine, And Respectively the first The modulation depth and phase of the order spatial harmonics, The highest order of the spatially modulated harmonics; The step S5 specifically comprises the following steps: For modulated time domain signals Performing fast Fourier transform to obtain frequency spectrum ; Second-order IIR wave trap capable of linking with rotation angular velocity The expression is: Wherein, the Is the first For the left and right side band frequencies, For the period of the magnetic field sampling, Is in combination with The corresponding normalized angular frequency is used to determine, Is that The complex variables are transformed and the complex variables are used, Is along with the rotation angular velocity A pole module value of linkage; Frequency points needing to be suppressed in self-adaptive positioning of main peak and side band are detected through second-order IIR wave trap The expression is: Wherein, the A modulation frequency defined for non-uniformity of circumferential magnetization by the rotating magnet; in the frequency spectrum Removing frequency points to obtain signals after frequency point inhibition The expression is: Wherein, the Is a continuous multiplication symbol; Signals after frequency point inhibition Performing inverse fast Fourier transform to obtain noise-suppressing time domain magnetic field signal ; In step S7, the final dynamic magnetic vector signal map satisfies the following equation: Wherein, the For the final dynamic magnetic vector signal mapping, To be from the rotary reference axis To a magnetic sensor system Is provided with a fixed orthogonal rotation matrix of (a), Representing the axial direction Is a non-stationary magnetic field signal across the rotational speed.
2. 2. The method for compensating for the disturbance of the magnetic field vector of a rotating magnet based on adaptive spectrum tracking according to claim 1, wherein in step S4, the modulated time domain signal satisfies the following formula: Wherein, the Is the modulated time domain signal.
3. 3. The method for compensating for disturbance of magnetic field vector of rotating magnet based on adaptive spectrum tracking according to claim 2, wherein in step S6, the non-stationary magnetic field signal across the rotational speed satisfies the following equation: Wherein, the Is the first The time intervals are divided into points in each time interval, Is the first The time intervals are divided into points in each time interval, Is the rotation angular velocity At a time instant within the duration of (a), As the total number of time interval partitions, Representation of And splicing the noise suppression time domain magnetic field sequences on a unified time axis according to the time sequence corresponding to the time period.

Description

Rotating magnet magnetic field vector interference compensation method based on self-adaptive spectrum tracking Technical Field The invention relates to the technical field of digital signal processing of magnetic measurement signals, in particular to a rotating magnet magnetic field vector interference compensation method based on self-adaptive frequency spectrum tracking. Background In applications such as weak magnetic signal measurement, magnetic anomaly detection, and magnetic field reconstruction of a mobile platform, a three-component magnetic sensor is often used to obtain an environmental magnetic field signal vector sequence. However, the presence of rotating magnetic members (e.g., rotating bodies of permanent magnets or magnetized structures) near the platform can create periodic magnetic disturbances at the sensor of significant amplitude that may partially overlap the target weak magnetic signal over the frequency band, resulting in reduced signal-to-noise ratio and distorted characteristics. The existing suppression method mostly adopts notch filtering or empirical filtering with fixed parameters, and generally implicitly assumes that the interference frequency is constant. When the rotation angular velocity changes, the interference dominant frequency and its harmonics drift, and it is difficult for the fixed trap to continuously align with the noise frequency point, so that the problem of suppressing the failure or erroneously suppressing the target component occurs. In addition, when the projection relation is changed due to the fact that a fixed included angle exists between the sensor triaxial coordinates and the interference source reference axis or the platform posture is changed, coupling can be generated between triaxial components, and the difficulty of interference extraction and compensation is further increased. Disclosure of Invention In view of this, the invention provides a method for compensating the disturbance of the magnetic field vector of a rotating magnet based on adaptive spectrum tracking, so as to improve the filtering effect on noise frequency points and the disturbance compensation effect. A rotating magnet magnetic field vector interference compensation method based on adaptive spectrum tracking comprises the following steps: step S1, a reference digital model of a rotating magnetic component is established, an original magnetic measurement vector signal sequence of a three-component magnetic sensor at a preset observation point is obtained, and sectional framing and normalization are carried out according to a rotation period or a sliding window, so that a time domain observation vector for subsequent processing and steady-state mapping thereof are constructed; s2, short-time frequency spectrum tracking is carried out on the time domain observation vector so as to estimate rotation fundamental frequency and phase, and a limited harmonic model of each axial component is established under the constraint of the fundamental frequency, so that amplitude and phase parameters changing along with angular velocity are obtained; Step S3, establishing a spatial modulation function representing circumferential non-uniformity and amplitude-phase fluctuation, and generating a candidate frequency point set of a main peak and a side band according to the spatial modulation function; s4, combining the limited harmonic model with a spatial modulation function to obtain a modulated time domain signal containing a main peak-side band structure and a frequency domain expression thereof; S5, performing fast Fourier transform on the modulated time domain signal, adaptively updating parameters of a second-order IIR trap under the constraint of a candidate frequency point set, realizing on-line positioning and suppression of a main peak and a side band frequency point, and then obtaining a noise-suppressing time domain magnetic field signal through inverse fast Fourier transform; s6, performing equal-angle domain resampling and uniform time axis splicing on noise-suppressing time domain magnetic field signals of different angular velocity sections to obtain a rotating speed-crossing non-stationary magnetic field signal; And S7, defining a fixed orthogonal rotation matrix from a rotation reference axis to a magnetic sensor axis, carrying out vector fusion and coordinate consistency on the trans-rotation non-stationary magnetic field signals, and outputting final dynamic magnetic vector signal mapping and related parameters after interference compensation. The rotating magnet magnetic field vector interference compensation method based on the self-adaptive spectrum tracking has the following beneficial effects: (1) According to the invention, the modulated time domain signal is subjected to fast Fourier transform, the second-order IIR wave trap linked with the rotation angular velocity is constructed, and the frequency points needing to be restrained are detected by the second-order IIR wa