An electromagnetic compatibility test system, method, medium, device and terminal

Abstract

The application belongs to the technical field of electromagnetic compatibility test, and discloses an electromagnetic compatibility test system, method, medium, equipment and terminal, wherein a narrow-band signal extraction module is used to extract a narrow-band resident interference signal, a wide-band signal extraction module is used to extract a wide-band signal in a test result through threshold comparison, a narrow-band signal elimination module is used to eliminate the resident narrow-band interference signal in a test environment, a wide-band signal elimination module is used to eliminate the wide-band interference signal, wavelet analysis multi-resolution characteristics are used, a wavelet decomposition and reconstruction module is used to decompose and reconstruct the signal processed by the difference method, and secondary noise reduction is realized. The application uses the filtering method to reduce noise, can save the spikes and mutations in the useful signal, and retains the original signal; the difference noise reduction method and the wavelet noise reduction method are combined to reduce the environmental noise, the effectiveness of eliminating the noise in the environment is improved, and the accuracy of the electromagnetic compatibility test is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electromagnetic compatibility performance test, and particularly relates to an electromagnetic compatibility test system, method, medium, device and terminal. BACKGROUND

[0002] At present, the radiation emission experiment is an extremely important link in electromagnetic compatibility, and the field strength intensity of the outward radiation of electronic products is limited, wherein the method of measuring the field strength is a basic measurement method for measuring electronic equipment. Different countries and institutions have issued different electromagnetic compatibility standards, and different electronic equipment applications also need to meet different standards to achieve the electromagnetic compatibility requirement that the electronic equipment does not produce interference to the outside world when working. In the motion control system, the control board card, cable and motor produce outward radiation electromagnetic interference when working, which will affect the normal work of the system, and also cause interference to the operation of other systems in the surrounding environment, affect the normal operation of the system, and cause damage to the industrial control machine. The EUT is in a specific electromagnetic environment, and various dynamic or static environmental radiation sources exist around, such as high-power electrical equipment switches, high-voltage transmission lines, frequency modulation broadcast stations and radars, and the electromagnetic environment of the work site will change with time and the working condition of other equipment around, thereby affecting the accuracy of the radiation test result.

[0003] The elimination method of environmental noise mainly includes three kinds: one is to use the traditional difference method, the implementation process is as follows: turn off the EUT, use the receiver to sweep the frequency to obtain the environmental signal; turn on the EUT, keep the parameters of the test instrument unchanged, and test after the EUT works normally to obtain the mixed signal; difference calculation is performed on the two signals to obtain the EUT radiation emission spectrum curve after eliminating the environmental noise, and due to the fact that the frequency offset and amplitude deviation are not considered, the phenomenon of missing elimination occurs, and the signal distortion is caused. Two is to use the virtual darkroom technology, but the correlation of the environmental signals received by the main channel and the reference channel cannot be guaranteed, and the adaptive interference cancellation effect is affected. Three is the wavelet denoising method, which is very effective for the case where the frequency range of the known noise and the frequency band of the signal and the noise are separated from each other, and the denoising effect is poor for the white noise widely existing in actual application. At present, technical solutions that can solve the above problems are urgently needed.

[0004] Through the above analysis, the problems and defects of the prior art are as follows:

[0005] (1) The existing environmental noise elimination method uses the traditional difference method, which does not consider the frequency offset and amplitude deviation, resulting in the phenomenon of missing elimination, and causing signal distortion.

[0006] (2) The existing virtual anechoic chamber technology is affected because the correlation between the environmental signals received by the main channel and the reference channel cannot be guaranteed, thus affecting the adaptive interference cancellation effect.

[0007] (3) Existing wavelet denoising methods are not very effective at reducing white noise, which is widely present in practical applications. Summary of the Invention

[0008] To address the problems existing in the prior art, the present invention provides an electromagnetic compatibility testing system, method, medium, equipment and terminal, and particularly relates to an electromagnetic interference testing system, method, medium, equipment and terminal suitable for use in anechoic chamber environments.

[0009] This invention proposes an electromagnetic compatibility (EMC) testing method, which includes: extracting narrowband resident interference signals using a narrowband signal extraction module; extracting broadband signals from the test results using a broadband signal extraction module through threshold comparison; removing resident narrowband interference signals in the test environment using a narrowband signal removal module; removing broadband interference signals using a broadband signal removal module; and using the multi-resolution characteristics of wavelet analysis, decomposing and reconstructing the signal processed by the differential method using a wavelet decomposition and reconstruction module to achieve secondary noise reduction.

[0010] Furthermore, the electromagnetic compatibility testing method includes the following steps:

[0011] Step 1: Use the narrowband signal extraction module to extract narrowband persistent interference signals;

[0012] Step two: Extract broadband signals from the test results through dynamic threshold discrimination;

[0013] Step 3: Identify and eliminate resident narrowband interference signals in the test environment based on their identity.

[0014] Step 4: Use the broadband signal removal module to remove broadband interference signals;

[0015] Step 5: Use wavelet analysis to decompose and reconstruct the signal in the time and frequency domains.

[0016] Furthermore, the dynamic threshold determination in step two is shown in the following formula:

[0017] D ai ≥Y ai +6dB.

[0018] Furthermore, the extraction of the broadband signal in step two includes:

[0019] Create a broadband signal array;

[0020] The search satisfies a k >y kThe first frequency point f of +6dB condition k And the frequency point and the corresponding amplitude are saved to a two-dimensional array.

[0021] Check if the next frequency point meets a k > y k +6dB condition, if it meets, it is stored in the array, and the next point is searched; if it does not meet, calculate f0=(f min +f max ) / 2, B=f max -f min , if B / f0≥0.1, it is determined as a wideband signal.

[0022] Further, the same discrimination formula of the resident narrowband interference signal in the test environment in step three is:

[0023] E fi ±Δf≤D fj , E ai ±ΔA≤D aj ;

[0024] If the same discrimination condition is met, the measurement data is stored as device data D i , otherwise, the differential comparison is continued.

[0025] Further, the elimination of the wideband interference signal in step four includes:

[0026] According to the wideband signal discrimination condition, extract N wideband signals D wi and E wj , and judge whether the frequency bands of the two coincide;

[0027] If D wi and E wj coincide, calculate the average value of three adjacent points in D wi and E wj , and record D g,ave and E g,ave ;

[0028] Judge the size of D g,ave and E g,ave , and complete the storage of the corresponding data.

[0029] Further, the signal decomposition and reconstruction in time domain and frequency domain using wavelet analysis in step five includes:

[0030] For the radiation signal containing noise, select the optimal wavelet and decomposition level;

[0031] Select a threshold for quantization operation on the wavelet coefficients at each decomposition scale;

[0032] The wavelet coefficients after noise removal are reconstructed to obtain the secondary noise reduction result.

[0033] Another object of the present invention is to provide an electromagnetic compatibility testing system applying the aforementioned electromagnetic compatibility testing method, the electromagnetic compatibility testing system comprising:

[0034] Narrowband signal extraction module, used to extract narrowband persistent interference signals;

[0035] The broadband signal extraction module is used to extract the broadband signal from the test results using a threshold comparison method.

[0036] Narrowband signal rejection module, used to reject persistent narrowband interference signals in the test environment;

[0037] A broadband signal rejection module is used to reject broadband interference signals.

[0038] The wavelet decomposition and reconstruction module is used to decompose and reconstruct the signal after differential processing by utilizing the multi-resolution characteristics of wavelet analysis, thereby achieving secondary noise reduction.

[0039] Furthermore, the narrowband signal extraction module and the broadband signal extraction module are also used to record the measurement results of the anechoic chamber environment when the equipment is off and the measurement results when the electronic equipment is in operation, respectively.

[0040] The narrowband signal rejection module and the wideband signal rejection module are also used to measure environmental data when the equipment is off, instrument low-noise data, and test data when the equipment is in operation.

[0041] Another object of the present invention is to provide a computer device, the computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the electromagnetic compatibility test method.

[0042] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the electromagnetic compatibility testing method.

[0043] Another objective of this invention is to provide an information data processing terminal for implementing the aforementioned electromagnetic compatibility testing system.

[0044] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0045] First, addressing the technical problems existing in the prior art and the difficulty of solving them, this paper closely analyzes, in conjunction with the technical solution to be protected by this invention and the results and data obtained during the research and development process, how the technical solution of this invention solves the technical problems, and the inventive technical effects brought about by solving these problems. The specific description is as follows:

[0046] This invention provides an electromagnetic interference testing method suitable for anechoic environments. It uses wavelet analysis to distinguish between useful and noise signals, and employs a filtering method for noise reduction, effectively preserving spikes and abrupt changes in the useful signal while retaining the original signal. This invention combines differential denoising with wavelet denoising analysis to reduce environmental noise, improving the effectiveness of noise removal and the accuracy of electromagnetic compatibility testing.

[0047] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by this invention are specifically described as follows:

[0048] This invention provides an electromagnetic compatibility testing system that combines differential methods and wavelet analysis to remove environmental noise from the test results, thereby improving the accuracy of the system's test results.

[0049] Third, as supplementary evidence of the inventive step of the claims of this invention, it is also reflected in the following important aspects:

[0050] (1) The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0051] After the technical solution of this invention is transformed, it can be applied to the electromagnetic compatibility testing of speed sensors in train control systems, enabling the speed sensors to provide speed information to the train control system and ensuring the normal operation of the speed sensors. After the technical solution of this invention is transformed, it can be applied to the electromagnetic compatibility testing of onboard equipment signal systems, coordinating the lines, stations, and EMU trains in an orderly manner through control and communication functions to ensure the safe, reliable, and efficient operation of EMU trains on the lines. After the technical solution of this invention is transformed, it can solve the electromagnetic compatibility problems of airborne electronic equipment in complex electromagnetic environments, assisting designers in the electromagnetic compatibility management of airborne electronic equipment, and providing functions to assist manual electromagnetic compatibility analysis of the entire aircraft, effectively improving the efficiency and quality of electromagnetic compatibility management during aircraft development.

[0052] (2) Whether the technical solution of the present invention solves the technical problem that people have long wanted to solve but have never been able to solve successfully:

[0053] The technical solution of this invention has certain theoretical significance and engineering application value for improving the electromagnetic compatibility (EMC) of electronic equipment in signal systems. It can provide assistance for EMC theory research, EMC design, and system EMC management of electrical and electronic products. Based on EMC theory, this invention addresses the shortcomings of traditional signal system risk studies that lack consideration of EMC testing methods. Attached Figure Description

[0054] To more clearly illustrate the technical solutions implemented in this invention, the accompanying drawings used in the embodiments of this invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart of the electromagnetic compatibility testing method provided in the embodiments of the present invention;

[0056] Figure 2 This is a schematic diagram of the electromagnetic compatibility testing method provided in an embodiment of the present invention;

[0057] Figure 3 This is a flowchart of the broadband signal extraction process in the electromagnetic compatibility testing system provided in this embodiment of the invention;

[0058] Figure 4 This is a flowchart of narrowband signal rejection in the electromagnetic compatibility testing system provided in this embodiment of the invention;

[0059] Figure 5 This is a flowchart of the broadband signal rejection process in the electromagnetic compatibility testing system provided in this embodiment of the invention;

[0060] Figure 6 This is a diagram of the adaptive wavelet 3-layer decomposition structure provided in an embodiment of the present invention;

[0061] Figure 7 This is a comparison diagram of the noise removal process before and after noise removal provided in an embodiment of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0063] To address the problems existing in the prior art, the present invention provides an electromagnetic compatibility testing system, method, medium, device, and terminal. The present invention will be described in detail below with reference to the accompanying drawings.

[0064] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanatory description of the embodiments that expand upon the technical solutions of the claims.

[0065] like Figure 1 As shown, the electromagnetic compatibility testing method provided in this embodiment of the invention includes the following steps:

[0066] S101, the narrowband signal extraction module is used to extract the narrowband persistent interference signal, and the broadband signal extraction module is used to extract the broadband signal in the test result by threshold comparison.

[0067] S102, the narrowband signal elimination module is used to eliminate the persistent narrowband interference signals in the test environment, and the broadband signal elimination module is used to eliminate the broadband interference signals.

[0068] S103 utilizes the multi-resolution characteristics of wavelet analysis to decompose and reconstruct the signal processed by the difference method through the wavelet decomposition and reconstruction module, thereby achieving secondary noise reduction.

[0069] As a preferred embodiment, such as Figure 2 As shown, the electromagnetic compatibility testing method provided in this embodiment of the invention specifically includes: a narrowband signal elimination module to eliminate resident narrowband interference signals in the test environment; a narrowband signal and broadband signal extraction module to extract broadband signals from the test results through threshold comparison; a broadband signal elimination module to eliminate broadband interference signals; and a wavelet decomposition and reconstruction module to decompose and reconstruct the results obtained by the difference method using the multi-resolution characteristics of wavelet analysis to achieve secondary noise reduction.

[0070] The narrowband and broadband signal extraction module provided in this embodiment of the invention requires the device under test to be turned off, and the spectrum data of the anechoic chamber environment where the device under test is located to be measured; the device under test is turned on to make it work, the parameter settings are kept unchanged, and the test results of the scanning environment and the device are superimposed into mixed data.

[0071] In the narrowband and wideband signal extraction module provided in this embodiment of the invention, wideband signal is relative to narrowband signal; a signal that does not meet the conditions for wideband signal is a narrowband signal.

[0072] The broadband signal extraction module provided in this embodiment of the invention should create a broadband signal array;

[0073] The search satisfies a k >y k The first frequency point f under the +6dB condition k Save the frequency point and its corresponding amplitude to a two-dimensional array;

[0074] Check if the next frequency point meets the above conditions. If it does, store it in the array and continue searching for the next point. If it does not meet the conditions, calculate f0 = (fmin +f max ) / 2, B=f max -f min If B / f0 ≥ 0.1, it is determined to be a broadband signal, and a broadband signal array is created again; otherwise, the array is cleared and the search for frequency points that meet the conditions continues.

[0075] The present invention provides a method for separating mixed data from broadband signals in the environment using a threshold function, and for counting the amount of broadband in the mixed data, using the instrument noise floor as the threshold.

[0076] In actual testing, if the spectrum analyzer is enabled for attenuation, the noise floor data will be increased by the attenuation value first; if the prevention function is enabled, the noise floor data will be decreased by 20dB first.

[0077] If the amplitude of the environmental scan data is higher than the threshold, and the test data when the device under test is turned on is more than 6dB higher than the environmental data, then the mixed data of the corresponding frequency point will be directly stored as the data of the device under test.

[0078] Determine whether the broadband signal in the mixed data overlaps with the broadband signal in the environment. If they overlap, perform grouped differential calculations within the overlapping frequency points; otherwise, directly store the broadband signal in the mixed data.

[0079] The amplitude of the broadband signal is compared with the environmental noise threshold at each frequency point until all data is processed. All stored results are then integrated into a whole data segment in frequency order.

[0080] The embodiments of the present invention use wavelet analysis to distinguish between useful signals and noise signals in a signal, and use filtering methods to denoise, which can better preserve the spikes and abrupt changes in the useful signal while retaining the original signal.

[0081] For the denoised radiation signal, the optimal wavelet and decomposition level are selected for wavelet decomposition.

[0082] For the wavelet coefficients at each decomposition scale, a threshold is selected for quantization.

[0083] The wavelet coefficients after noise removal are reconstructed to obtain the secondary denoised signal.

[0084] The high signal-to-noise ratio electromagnetic compatibility testing system provided in this embodiment of the invention includes:

[0085] Narrowband signal extraction module, used to extract narrowband persistent interference signals;

[0086] The broadband signal extraction module is used to extract the broadband signal from the test results using a threshold comparison method.

[0087] Narrowband signal rejection module, used to reject persistent narrowband interference signals in the test environment;

[0088] A broadband signal rejection module is used to reject broadband interference signals.

[0089] The wavelet decomposition and reconstruction module is used to decompose and reconstruct the signal after differential processing by utilizing the multi-resolution characteristics of wavelet analysis, thereby achieving secondary noise reduction.

[0090] To demonstrate the inventiveness and technical value of the technical solution of this invention, this section provides specific product or related technology application examples of the technical solution claimed.

[0091] Application 1: High-speed railways are characterized by speed, comfort, punctuality, affordability, and safety. The onboard signaling system is a crucial component responsible for operational control. Through control and communication functions, it coordinates the track, stations, and train sets in an orderly manner to ensure the safe, reliable, and efficient operation of the trains. The complex electromagnetic environment of high-speed rail systems poses a significant threat to the onboard signaling system. This system controls train operation through communication, control, and antenna ports distributed throughout the train. The technical solution of this invention can be applied to the electromagnetic compatibility performance testing of onboard signaling systems.

[0092] Application 2: Due to the wide variety of modern aircraft avionics, characterized by high frequency, high processing speed, high sensitivity, high installation density, and high integration, electromagnetic compatibility (EMC) issues in complex electromagnetic environments are significant and complex problems for aircraft. The technical solution of this invention can be applied to the EMC performance testing of aircraft avionics.

[0093] Application 3: With the rapid development of high-speed devices, the digital signal frequencies of information technology equipment are increasing, and the frequency range of leakage emissions is also widening. The development of testing equipment is far from meeting the needs of assessing leakage emission risks. Existing electromagnetic compatibility (EMC) testing methods and techniques cannot effectively test and assess conducted leakage emission risks, especially since the intermediate frequency bandwidth of the measuring receiver is insufficient to meet testing requirements. The technical solution of this invention can be applied to the EMC performance testing of high-speed information technology equipment.

[0094] The embodiments of the present invention have achieved some positive results during the research and development or use process, and have indeed great advantages compared with the prior art. The following content describes the experimental process with data, charts and other information.

[0095] In field testing, this embodiment of the invention requires separate processing of broadband and narrowband signals when eliminating environmental noise. A broadband signal is relative to a narrowband signal; a signal that does not meet the criteria for a broadband signal is a narrowband signal, and vice versa. Considering the signal frequency amplitude point as (f...k ,a k ), threshold is y k minimum frequency point f min Maximum frequency point f max The frequency unit is Hz, and the amplitude unit is dBμV / m.

[0096] like Figure 3 As shown, the flow of the broadband signal extraction method provided in this embodiment of the invention is as follows:

[0097] Turn off the device under test and measure the spectral data of the anechoic chamber environment where the device is located;

[0098] Turn on the device under test to make it work, keep the parameter settings unchanged, and overlay the test results of the scanning environment and the device into mixed data;

[0099] In processing broadband signals, this embodiment of the invention first obtains the overall bandwidth and center frequency, then performs in-band threshold calculation, then performs in-band differential calculation, and finally obtains the elimination result that retains the signal envelope information, thus improving the problem of broadband signal envelope loss caused by single-point differential calculation.

[0100] The broadband signal extraction process provided in this embodiment of the invention includes:

[0101] Create a broadband signal array;

[0102] The search satisfies a k >y k The first frequency point f under the +6dB condition k Save the frequency point and its corresponding amplitude to a two-dimensional array;

[0103] Check if the next frequency point meets the above conditions. If it does, store it in the array and continue searching for the next point. If it does not meet the conditions, calculate f0 = (f min +f max ) / 2, B=f max -f min If B / f0 ≥ 0.1, it is determined to be a broadband signal, and a broadband signal array is created; otherwise, the array is cleared and the search continues to satisfy a. k >y k Frequency points under the +6dB condition.

[0104] The narrowband signal rejection process provided in this embodiment of the invention is as follows: Figure 4 As shown;

[0105] Among them, Y i E represents threshold data. i Represents environmental data, D i This represents mixed data, with units of (Hz, dBμV / m), Y aiE represents the threshold amplitude. ai D represents the magnitude of environmental data. ai Y1 represents the amplitude of the mixed data, in dBμV / m. i E1 i D1 i This indicates the amplitude of the corresponding field strength data after unit conversion, in V / m.

[0106] When the ambient data amplitude is less than the threshold, the mixed data will be stored as device data. This is because when the ambient amplitude is less than the threshold, it indicates that the ambient noise at this frequency is low and does not have a significant impact on the test results.

[0107] If the environmental data amplitude is higher than the threshold, then proceed with the subsequent calculation. If the environmental data amplitude is higher than the threshold, and the data when the device under test is turned on is greater than the environmental data by less than 6 dB, since the unit is dBμV / m, the two data are not linearly related. Therefore, the unit should be converted from dBμV / m to μV before differential calculation.

[0108] In this embodiment of the invention, the two sets of data after unit conversion are compared: if the difference between the data measured after turning on the device under test and the environmental data is greater than the instrument noise floor, the difference is converted to dBμV / m and stored as the device data at the corresponding frequency point; if the difference between the data measured after turning on the device under test and the environmental data is less than or equal to the instrument noise floor, the data when the device under test is turned on is directly stored as the data at the corresponding frequency point, until all the original data has been processed.

[0109] The broadband signal rejection process provided in this embodiment of the invention is as follows: Figure 5 As shown, a broadband signal extraction method is used to separate the mixed data from the broadband signals in the environment, and the number of broadband signals in the mixed data is counted.

[0110] Determine whether the broadband signal in the mixed data overlaps with the broadband signal in the environment. If they overlap, perform grouped differential calculations within the overlapping frequency points; otherwise, directly store the broadband signal in the mixed data.

[0111] Among them, D wi For the i-th wideband signal in the mixed data, E wj Let D be the j-th broadband signal in the environmental data, with units of (Hz, dBμV / m). a,ave E represents the average value of three adjacent points of the i-th broadband signal. a,ave D represents the average value of three adjacent points in the j-th broadband signal. gk This represents a frequency point in broadband.

[0112] The secondary noise reduction module based on wavelet analysis includes wavelet decomposition and reconstruction. Wavelet analysis can analyze signals in both the time and frequency domains simultaneously. It has low time resolution in the low-frequency band and high time resolution in the high-frequency band, thereby distinguishing between useful signals and noise signals. Using this filtering method for noise reduction can better preserve the spikes and abrupt changes in the useful signal while retaining the characteristics of the original signal.

[0113] The wavelet denoising process provided in this embodiment of the invention includes:

[0114] For the radiation signal X(t) after denoising using the differential method, the optimal wavelet and decomposition level are selected for wavelet decomposition;

[0115] For the wavelet coefficients at each decomposition scale, a threshold is selected for quantization.

[0116] The wavelet coefficients after noise removal are reconstructed to obtain the secondary denoised signal.

[0117] The noise reduction requirements differ for different frequency bands of the signal, so different selection criteria are needed to perform two adaptive wavelet packet decomposition and reconstruction noise reduction methods.

[0118] By comparing the spectral range of the signals of each reconstructed node of the wavelet packet, the existing nodes are determined. The wavelet is then adaptively selected a second time so that the frequency range of the nodes after the three-level decomposition of the wavelet packet is in the segment with the maximum percentage of signal energy.

[0119] The radiation signal that has undergone preliminary noise reduction is used to adaptively select the wavelet with the largest energy percentage after the two nodes mentioned above using the wenergy function in Matlab, and then perform a second wavelet packet decomposition.

[0120] The adaptive wavelet 3-level decomposition structure provided in this embodiment of the invention is as follows: Figure 6 As shown, the first-level wavelet decomposition decomposes the signal X with a frequency band of 0 to f into a low-frequency part A1 of 0 to 0.5f and a high-frequency part D1 of 0.5f to f. The second-level wavelet decomposition further decomposes the low-frequency part A1 into a low-frequency part A2 of 0 to 0.25f and a high-frequency part D2 of 0.25f to 0.5f. The third-level wavelet decomposition further decomposes the low-frequency part A2 into a low-frequency part A3 of 0 to 0.125f and a high-frequency part D3 of 0.125f to 0.25f.

[0121] like Figure 7 As shown, the embodiments of the present invention improve the effectiveness of noise removal in the environment and enhance the accuracy of electromagnetic compatibility testing by combining differential denoising and wavelet denoising methods in a complementary manner.

[0122] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented using hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or using software executed by various types of processors, or using a combination of the above-described hardware circuitry and software, such as firmware.

[0123] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An electromagnetic compatibility testing method, characterized in that, The electromagnetic compatibility testing method includes: extracting narrowband resident interference signals using a narrowband signal extraction module; extracting broadband signals from the test results using a broadband signal extraction module through threshold comparison; removing resident narrowband interference signals in the test environment using a narrowband signal removal module; removing broadband interference signals using a broadband signal removal module; and using the multi-resolution characteristics of wavelet analysis, decomposing and reconstructing the signal processed by the differential method using a wavelet decomposition and reconstruction module to achieve secondary noise reduction. Electromagnetic compatibility testing methods include the following steps: Step 1: Use the narrowband signal extraction module to extract narrowband persistent interference signals; Step two: Extract broadband signals from the test results through dynamic threshold discrimination; Step 3: Identify and eliminate resident narrowband interference signals in the test environment based on their identity. Step 4: Use the broadband signal removal module to remove broadband interference signals; Step 5: Decompose and reconstruct the signal in the time and frequency domains using wavelet analysis; The dynamic threshold determination in step two is shown in the following formula: D ai ≥Y ai +6dB; Y ai D represents the threshold amplitude. ai Indicates the magnitude of the mixed data; Step two, the extraction of the broadband signal, includes: Create a broadband signal array; The search satisfies a k >y k The first frequency point f under the +6dB condition k And save the frequency points and corresponding amplitudes to a two-dimensional array, considering that the signal frequency amplitude points are (f k ,a k ), threshold is y k ; Check if the next frequency point satisfies a. k >y k If the condition of +6dB is met, store it in an array and continue searching for the next point; otherwise, calculate f0 = (f min +f max ) / 2, B=f max -f min If B / f0 ≥ 0.1, it is determined to be a broadband signal with the minimum frequency point f. min Maximum frequency point f max .

2. The electromagnetic compatibility testing method as described in claim 1, characterized in that, Step five, which involves using wavelet analysis to decompose and reconstruct the signal in the time and frequency domains, includes: For noisy radiated signals, select the optimal wavelet and decomposition level; For the wavelet coefficients at each decomposition scale, a threshold is selected for quantization. The wavelet coefficients after noise removal are reconstructed to obtain the secondary noise reduction result.

3. An electromagnetic compatibility testing system applying the electromagnetic compatibility testing method as described in any one of claims 1 to 2, characterized in that, Electromagnetic compatibility testing systems include: Narrowband signal extraction module, used to extract narrowband persistent interference signals; The broadband signal extraction module is used to extract the broadband signal from the test results using a threshold comparison method. Narrowband signal rejection module, used to reject persistent narrowband interference signals in the test environment; A broadband signal rejection module is used to reject broadband interference signals. The wavelet decomposition and reconstruction module is used to decompose and reconstruct the signal after differential processing by utilizing the multi-resolution characteristics of wavelet analysis, thereby achieving secondary noise reduction.

4. The electromagnetic compatibility testing system as described in claim 3, characterized in that, The narrowband signal extraction module and the broadband signal extraction module are also used to record the measurement results of the anechoic chamber environment when the equipment is off and the measurement results when the electronic equipment is in operation, respectively. The narrowband signal rejection module and the wideband signal rejection module are also used to measure environmental data when the equipment is off, instrument low-noise data, and test data when the equipment is in operation.

5. A computer device, characterized in that, The computer device includes a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the electromagnetic compatibility test method as described in any one of claims 1 to 2.

6. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the electromagnetic compatibility test method as described in any one of claims 1 to 2.

7. An information data processing terminal, characterized in that, The information data processing terminal is used to implement the electromagnetic compatibility testing system as described in any one of claims 3 to 4.

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