Method for synthesizing and extracting characteristic signals of motion alternating magnetic body induction coil timing

Abstract

This invention provides a method for synthesizing and extracting characteristic signals from the timing sequence of an induction coil of a moving alternating magnetic body. The method proposes a calculation method for the induction coil time series and synthesizes the induction coil time series based on model parameters. To extract the characteristic signals of the timing sequence, Fourier transform and power spectrum analysis are performed on the time series, and the frequency with the strongest energy is taken as the excitation frequency of the magnetic body. The initial phase of the transmitting source is analyzed using coherent signal technology of the same frequency. The alternating field response and static field response of the induction coil timing sequence are analyzed using coherent signal technology of the same frequency and phase. The key feature of this invention is that it proposes a calculation method for the induction coil time series and combines signal coherence technology and filtering technology to analyze the characteristic response of the induction coil timing sequence. Compared with traditional methods, this method is simple and easy to implement, and can be integrated into electronic circuits. This invention provides a technical solution for evaluating the effectiveness of data processing technology and extracting characteristic signals from the induction coil of a moving alternating magnetic body, and has practical application value.

Description

Technical Field

[0001] This invention belongs to the field of magnetic exploration technology, specifically relating to a method for synthesizing the timing sequence of an induction coil of a moving alternating magnetic body and extracting its characteristic signals. Background Technology

[0002] Moving targets such as surface ships are typically composed of ferromagnetic materials. The remanence and magnetization of these ferromagnetic materials themselves constitute a magnetic source, generating a static magnetic field. Furthermore, electromagnetic fuses, as the most widely used non-trigger fuses on surface ships and underwater vehicles, radiate alternating magnetic field signals of a certain frequency into the surrounding seawater via a transmitting coil. When the distance between the magnetic field detection device and the target is much larger than the geometric dimensions of the underwater vehicle's transmitting antenna, the electromagnetic fuse can be approximated as an alternating magnetic dipole source. Both static and alternating magnetic field signals are characteristic signals of magnetic bodies. By collecting and processing the corresponding magnetic field signals using a magnetic field detection device, the target's position information can be obtained.

[0003] Magnetic induction coils are magnetic field sensors based on electromagnetic induction. Their sensitivity depends on the permeability of the core material, the coil area, and the number of turns. Magnetic induction coils have a wider detection sensitivity range than other sensors, making them highly suitable for capturing weak alternating magnetic fields. The signals received by the sensor need to be processed to extract the characteristic signals of the magnetic target before they can be applied to target feature analysis and localization studies. However, high signal-to-noise ratio target signals are often difficult to obtain from actual measurements, posing challenges to the feature analysis and localization of magnetic targets. Furthermore, the effectiveness of noise suppression techniques needs to be effectively evaluated and verified. However, the effective and noise signal components in measured electromagnetic signals are unknown, making it impossible to verify processing techniques. Therefore, it is necessary to utilize known simulation data to conduct these studies. Researching the synthesis of timing sequences and characteristic signal extraction methods for induction coils of moving alternating magnetic bodies can provide important technical support for the feature analysis and target localization of alternating magnetic targets, making it a work of practical significance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for synthesizing the timing of an induction coil of a moving alternating magnetic body and extracting its characteristic signals. This method can be applied to the characteristic analysis of alternating magnetic targets and the research on target localization methods.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body, comprising the following steps:

[0006] S1. Set the model parameters, including the excitation frequency, starting position, motion speed, magnetic moment, and initial phase of the alternating magnetic body, as well as the sensor position, sampling rate, and acquisition time.

[0007] S2. Synthesize induction coil time series based on model parameters;

[0008] S3. Obtain the excitation frequency of the alternating magnetic material from the time series;

[0009] S4. Process the timing sequence and analyze it to obtain the initial phase of the transmitter;

[0010] S5. Based on the excitation frequency and initial phase of the obtained alternating magnetic body, the alternating field response is obtained analytically;

[0011] S6. Based on the excitation frequency and initial phase of the obtained alternating magnetic material, the static field response is obtained analytically.

[0012] The calculation method for synthesizing induction coil time series based on model parameters, as described in S2, is as follows:

[0013]

[0014] In the formula, For the timing of the induction coil, For alternating field response, For static field response, For the magnetic field gradient tensor, Let ω be the velocity vector of the transmitter, t be the time vector, and φ be the initial phase of the transmitter.

[0015] The method described in S3 for obtaining the excitation frequency of an alternating magnetic material involves performing a Fourier transform on the time series and conducting power spectrum analysis, then using the frequency with the strongest energy as the excitation frequency.

[0016] The specific steps described in S4 for obtaining the initial phase of the emission source are as follows:

[0017] S1. Multiply the signal by the signals of the same frequency, a = sin(ωt) and b = cos(ωt), respectively, to obtain the new signal S. a (t)

[0018] and S b (t), where ω is the angular frequency of the emission source and t is the time vector;

[0019] S2, for signal S a (t) and S b (t) Perform active low-pass filtering to obtain the DC component. and

[0020] S3, will and By performing a ratio calculation and taking the arctangent, the initial phase of the emission source can be obtained.

[0021] The specific steps described in S5 for analytically obtaining the alternating field response based on the excitation frequency and initial phase of the obtained alternating magnetic material are as follows:

[0022] S1. Multiply the signal by the in-phase signal c = cos(ωt + φ) to obtain the new signal S. c (t), where ω is the angular frequency of the source, t is the time vector, and φ is the initial phase of the source;

[0023] S2, for signal S c (t) Perform active low-pass filtering to obtain the alternating field response.

[0024] The specific steps described in S5 for analytically obtaining the static field response based on the excitation frequency and initial phase of the alternating magnetic body are as follows:

[0025] S1. Multiply the signal by the in-phase signal d = sin(ωt + φ) to obtain the new signal S. d (t), where ω

[0026] Let ω be the angular frequency of the source, t be the time vector, and φ be the initial phase of the source.

[0027] S2, for signal S d (t) Perform active low-pass filtering to obtain the static field response.

[0028] Compared with the prior art, the beneficial effects of the method provided in some embodiments of the present invention are as follows:

[0029] This invention primarily addresses the problems of the inability to effectively evaluate the effects of data processing techniques using measured data, and the inability to directly apply measured data to target localization. It proposes a method for synthesizing the time sequence of an induction coil from a moving alternating magnetic body and extracting its characteristic signals. This method proposes a calculation method for the induction coil time sequence, synthesizes the induction coil time sequence based on model parameters, performs Fourier transform on the time sequence and conducts power spectrum analysis, identifying the frequency with the strongest energy as the excitation frequency of the alternating magnetic body; it also utilizes coherent signaling techniques with the same frequency to analyze the initial phase of the transmitting source; and further utilizes coherent signaling techniques with the same frequency and phase to analyze the alternating field response and static field response of the induction coil time sequence of the moving alternating magnetic body.

[0030] This invention combines signal coherence and filtering techniques to analyze the initial phase of the transmitting source, as well as the alternating and static field responses of the induction coil of a moving alternating magnetic body. Compared to traditional feature signal extraction methods, this method is simpler, easier to implement, and can be integrated into electronic circuits. This invention provides a new technical solution for effectively evaluating the effectiveness of data processing techniques and extracting feature signals from the induction coil of a moving alternating magnetic body, and has practical application value. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of the method of the present invention;

[0033] Figure 2 A schematic diagram of the synthesis model of the timing sequence of the induction coil of a moving alternating magnetic body;

[0034] Figure 3 The timing sequence of the x-direction component of the synthesized induction coil;

[0035] Figure 4 The timing sequence of the synthesized induction coil in the y-direction direction;

[0036] Figure 5 The timing sequence of the z-direction component of the synthesized induction coil;

[0037] Figure 6 To analyze the alternating field response and static field response x-direction component obtained from the timing of the induction coil;

[0038] Figure 7 To analyze the alternating field response and static field response y-direction component obtained from the timing of the induction coil;

[0039] Figure 8 To analyze the alternating field response and static field response z-direction component obtained from the timing of the induction coil. Detailed Implementation

[0040] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] This invention provides a method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body. See the detailed calculation flowchart below. Figure 1 This includes the following steps.

[0042] S1. Set the model parameters, including the excitation frequency, starting position, motion speed, magnetic moment, and initial phase of the alternating magnetic body, as well as the sensor position, sampling rate, and acquisition time.

[0043] S2. Synthesizing the induction coil time series based on model parameters. The calculation method for synthesizing the induction coil time series based on model parameters is as follows:

[0044]

[0045] In the formula, For the timing of the induction coil, For alternating field response, For static field response, For the magnetic field gradient tensor, Let ω be the velocity vector of the transmitter, t be the time vector, and φ be the initial phase of the transmitter.

[0046] S3. Perform Fourier transform on the time series and conduct power spectrum analysis. Take the frequency with the strongest energy as the excitation frequency f of the alternating magnetic target. Then, the angular frequency ω can be obtained according to ω=2πf.

[0047] S4. Process the timing sequence to obtain the initial phase of the transmitter. The partial derivative of the magnetic field strength at the receiving point with respect to time (i.e., B) t It has the following forms

[0048] B t =αcos(ωt+φ)-βsin(ωt+φ)

[0049] Where ω is the angular frequency, t is the time vector, φ is the initial phase, and α and β are the alternating field responses, respectively. and static field response The component, that is Multiplying both sides of the above equation by sin(ωt) and cos(ωt) respectively, we get...

[0050] S a (t)=αcos(ωt+φ)sin(ωt)-βsin(ωt+φ)sin(ωt)

[0051] S b (t)=αcos(ωt+φ)cos(ωt)-βsin(ωt+φ)cos(ωt)

[0052] Transform using trigonometric function relationships, and apply S a (t) and S b (t) After being processed by an active low-pass filter, S can be filtered out. a (t) and S b The AC part in (t) is used to obtain the DC part.

[0053] Assumption and These are the results after processing by the active low-pass filter, i.e., the DC portion of the signal. Therefore, the above equation becomes...

[0054]

[0055] Will and By taking the ratio and then the arctangent, the initial phase of the emission source can be obtained. Therefore, we have

[0056]

[0057] S5. Based on the excitation frequency and initial phase of the obtained alternating magnetic material, the alternating field response is obtained analytically.

[0058] After obtaining the angular frequency ω and initial phase φ of the magnetic field signal radiated by the moving alternating magnetic dipole source, the signal is multiplied by the in-phase signal c = cos(ωt + φ) to obtain the new signal S. c (t):

[0059]

[0060] Where ω is the angular frequency, t is the time vector, φ is the initial phase, and α and β are the alternating field responses, respectively. and static field response The DC component is obtained after processing by an active low-pass filter, which yields the DC signal α, thus providing the alternating field response.

[0061] S6. Based on the excitation frequency and initial phase of the obtained alternating magnetic material, the static field response is analytically obtained. Multiplying the signal by the in-phase signal d = sin(ωt + φ) yields the new signal S. d (t):

[0062]

[0063] Where ω is the angular frequency, t is the time vector, φ is the initial phase, and α and β are the alternating field responses, respectively. and static field response The DC component is obtained after processing by an active low-pass filter, which yields the DC signal β, thus providing the static field response.

[0064] See Figure 2 The magnetic moment vector of the alternating magnetic target is (5,10,5)Am. 2 The magnetic target moves from the starting point (0,0,0)m towards the point (20,40,3) at a speed of (1,2,0)m / s. The frequency of the emission source is 10Hz, and the initial phase is 60°. A three-component magnetic induction coil sensor is constructed at (10,20,3)m, and the data sampling frequency of the sensor is set to 100Hz. When the magnetic target starts moving from the starting point, the sensor array begins to record measurement data, and the total recording time is 20s.

[0065] See Figures 3 to 5The timing sequence of the synthesized induction coils are respectively x-direction component timing y-direction component timing and the timing of the z-direction components As shown in the figure, when the alternating magnetic object approaches the sensor from a distance, the overall amplitude of the sensor's three components continuously increases, and as the alternating magnetic object moves away, the response amplitude continuously decreases, but the trends of change for the three components are significantly different. For the changing trend of the magnetic target passing above the receiving station, the x-direction component timing... Timing of y-direction components The trends and extreme value distributions are similar, while the z-direction component time series... The changing trend and extreme value distribution are opposite to the time series in the x and y directions.

[0066] See Figures 6 to 7 Based on the excitation frequency and initial phase of the obtained alternating magnetic body, the obtained alternating field response is analyzed. and static field response The three amplitude components, of which Figure 6 For alternating field response and static field response Component in the x-direction and B x0 , Figure 7 For alternating field response and static field response Component in the y direction and B y0 , Figure 8 For alternating field response and static field response Component in the z-direction and B z0 To verify the correctness of this method, we will use real alternating field responses. and static field response The diagram also shows the alternating field response as a dotted line. As can be seen from the diagram, the analytical alternating field response... and static field response The combined waveform shape and time series ( Figures 3 to 5 The results are consistent, which shows that the time series is actually the response of the alternating field. and static field response The mixed response. Compared to the actual alternating field response. and static field response The alternating field response analyzed by this method and static field response It was found that the two curves completely overlapped, which proves the correctness of the method proposed in this patent.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body, characterized in that, Includes the following steps: S1. Set the model parameters, including the excitation frequency, starting position, motion speed, magnetic moment, and initial phase of the alternating magnetic body, as well as the sensor position, sampling rate, and acquisition time. S2. Synthesizing the induction coil time series based on model parameters. The calculation method for synthesizing the induction coil time series based on model parameters is as follows: In the formula, For the timing of the induction coil, For alternating field response, For static field response, For the magnetic field gradient tensor, Let ω be the velocity vector of the transmitter, ω be the angular frequency of the transmitter, t be the time vector, and φ be the initial phase of the transmitter. S3. Obtain the excitation frequency of the alternating magnetic material from the time series; S4. Process the timing sequence and analyze it to obtain the initial phase of the transmitter; S5. Based on the excitation frequency and initial phase of the obtained alternating magnetic body, the alternating field response is obtained analytically; S6. Based on the excitation frequency and initial phase of the obtained alternating magnetic material, the static field response is obtained analytically.

2. The method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body as described in claim 1, characterized in that, The method described in S3 for obtaining the excitation frequency of an alternating magnetic material involves performing a Fourier transform on the time series and conducting power spectrum analysis, then using the frequency with the strongest energy as the excitation frequency.

3. The method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body as described in claim 1, characterized in that, The specific steps described in S4 for obtaining the initial phase of the emission source are as follows: S1. Multiply the signal by the signals of the same frequency, a = sin(ωt) and b = cos(ωt), respectively, to obtain the new signal S. a (t) and S b (t), where ω is the angular frequency of the emission source and t is the time vector; S2, for signal S a (t) and S b (t) Perform active low-pass filtering to obtain the DC component. and S3, will and By performing a ratio calculation and taking the arctangent, the initial phase of the emission source can be obtained.

4. The method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body as described in claim 1, characterized in that, The specific steps described in S5 for analytically obtaining the alternating field response based on the excitation frequency and initial phase of the obtained alternating magnetic material are as follows: S1. Multiply the signal by the in-phase signal c = cos(ωt + φ) to obtain the new signal S. c (t), where ω is the angular frequency of the source, t is the time vector, and φ is the initial phase of the source; S2, for signal S c (t) Perform active low-pass filtering to obtain the alternating field response.

5. The method for synthesizing the timing sequence and extracting characteristic signals of an induction coil of a moving alternating magnetic body as described in claim 1, characterized in that, The specific steps described in S5 for analytically obtaining the static field response based on the excitation frequency and initial phase of the alternating magnetic body are as follows: S1. Multiply the signal by the in-phase signal d = sin(ωt + φ) to obtain the new signal S. d (t), where ω Let ω be the angular frequency of the source, t be the time vector, and φ be the initial phase of the source. S2, for signal S d (t) Perform active low-pass filtering to obtain the static field response.

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