Ultrasonic spectrum cross-scale particle size distribution detection method, system, device and storage medium

Abstract

The application discloses an ultrasonic spectrum cross-scale particle size distribution detection method and system, which comprises the following steps: generating multiple groups of burst sound emission signals with different frequency ranges based on a pre-constructed linear frequency modulation signal constraint; sequentially exciting multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through a liquid to be detected; recording the received signals passing through pure water and the liquid to be detected; calculating the amplitude information and the attenuation coefficient of the received signal waveform at multiple different frequencies; constructing the attenuation coefficient at different frequencies and forming an observation matrix G; combining a coupled phase model HT and a BLBL analog optical absorption law to construct a theoretical model matrix A; performing inversion by calculating the following formula: AF=G, to obtain a solid-liquid two-phase medium particle size distribution F. By combining multiple groups of transducers with different frequency bands into an array, wideband detection from several kHz to several tens of MHz is realized, and finally the particle size scale range is from several microns to several millimeters, which is suitable for the detection requirements of high and low volume concentration particle size distribution.

Description

Technical Field

[0001] This invention relates to the field of particle size distribution detection technology, and in particular to a method, system, device and storage medium for ultrasonic spectrum cross-scale particle size distribution detection. Background Technology

[0002] Solid-liquid two-phase media refer to mixtures containing both solid particles and liquids, and are widely used in ore processing, water quality testing, dairy production, pharmaceutical research and development, and river sediment monitoring. Particle size distribution refers to the percentage of particles of different sizes among the total number of particles, and is an important parameter of solid-liquid two-phase media, playing a crucial role in the quality and performance of the product.

[0003] Currently, the main methods for detecting particle size distribution in solid-liquid two-phase media are: 1) microscopy, 2) sedimentation, 3) dynamic light scattering, and 4) ultrasonic spectroscopy. Microscopy measures particle size using an electron microscope combined with image processing algorithms to obtain particle size distribution. While accurate, this method is time-consuming and offline, making it unsuitable for online industrial applications. Sedimentation calculates particle size using the Stokes sedimentation formula, determining the final settling time of particles of different sizes in a fluid. Its measurement range is related to the physical properties of the medium, and the measurement time is relatively long. Dynamic light scattering is currently the most widely used method, with the highest market share for related products. It measures particle size distribution by utilizing the relationship between particle size and light scattering parameters. This method is fast and accurate; however, it is difficult to apply to suspensions with poor light transmittance and high viscosity, and dilution of the original solution may also affect the particle size distribution. Ultrasonic spectroscopy offers advantages such as strong sound wave penetration, non-contact operation, and no disturbance, enabling effective measurement of particle size distribution in high-concentration, opaque, and multiphase systems. However, current ultrasonic spectral analysis methods suffer from limitations such as limited particle size detection scale and low accuracy of inversion algorithms, which restrict their widespread application. Therefore, designing a particle size distribution detection method with high measurement accuracy and a wide detection range is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, device, and storage medium for ultrasonic spectrum cross-scale particle size distribution detection. By combining multiple sets of transducers with different frequency bands into an array, broadband detection with a detection frequency band from several kHz to tens of MHz is achieved, ultimately meeting the detection requirements for particle size scales from several micrometers to several millimeters. Using linear frequency modulated signals to excite the transmitting transducers at different frequency bands and demodulating the received frequency modulated signals separately to obtain the received signal amplitude in that frequency band, effectively shortens the detection time and is applicable to complex and variable multiphase flow processes, meeting the requirements for rapid measurement.

[0005] The technical solution of this invention is: a method for detecting cross-scale particle size distribution using ultrasonic spectra, applied to a detection system with multiple transducers of different driving frequency ranges, comprising:

[0006] Based on the pre-constructed linear frequency modulation signal constraint, multiple sets of burst emission signals with different frequency ranges are generated to sequentially excite multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through the liquid under test. The received signals passing through pure water and the liquid under test are recorded. The amplitude information and attenuation coefficient of the received signal waveform at multiple different frequencies are calculated.

[0007] Attenuation coefficients of different frequencies are constructed and formed into an observation array G. The theoretical model matrix A is constructed by combining the coupled phase model (Harker and Temple) HT and the BLBL analogous to the optical absorption law. The particle size distribution F of the solid-liquid two-phase medium is obtained by inversion using the following formula: AF = G.

[0008] Preferably, the pre-constructed linear frequency modulation signal constraint formula is as follows:

[0009] Where B is the transducer bandwidth, T is the duration of the linear frequency modulated signal, f0 is the transducer's -6dB frequency lower limit, t is time, and w(t) is the window function.

[0010] Preferably, calculating the amplitude information of the received signal waveform at multiple different frequencies further includes:

[0011] Based on formula Calculate amplitude information at multiple different frequencies, where R d (w) represents the Fourier transform of the received burst signal at frequency ω, R c (w) represents the Fourier transform of the received linear frequency modulated signal, E d (w) represents the Fourier transform of the burst excitation signal at frequency ω, E c (w) represents the Fourier transform of the transmitted linear frequency modulated signal;

[0012] For R d (w) Perform inverse Fourier transform to obtain the amplitude of the received signal at different frequencies.

[0013] Preferably, calculating the attenuation coefficient of the received signal waveform at multiple different frequencies further includes:

[0014] Based on formula Calculate the attenuation coefficient α, where V R V E These are the received voltage values ​​in the liquid-solid two-phase medium and the received voltage value in the pure water medium at this frequency, respectively, and D is the distance between the transmitting and receiving transducers.

[0015] Preferably, attenuation coefficients of different frequencies are constructed and formed into an observation array G. A theoretical model matrix A is constructed by combining the coupled phase model (Harker and Temple) HT and the BLBL analogous to the optical absorption law. The particle size distribution F of the solid-liquid two-phase medium is obtained by inversion using AF=G. Three frequency points are selected for demodulation in each frequency range and an attenuation coefficient observation array G is constructed.

[0016] Furthermore, a model is constructed by combining the coupled phase model (Harker and Temple) HT and the BLBL model analogous to the optical absorption law;

[0017] α=α HT +α BLBL

[0018] Wherein, α is the attenuation coefficient of the combined model of the present invention; α HT and α BLBL These are the attenuation coefficients for the HT model and the BLBL model, respectively.

[0019] Preferably, the frequency ranges of the generated burst emission signals of different frequency ranges are: 100kHz~300kHz, 500kHz~1MHz, 1MHz~3MHz, 5MHz~10MHz, and 10MHz~30MHz, respectively, and the duration of the burst emission signal is 8µs, which sequentially excite five sets of transmitting transducers of different frequency bands.

[0020] Preferably, the method further includes:

[0021] The obtained particle size distribution results of the solid-liquid two-phase medium were compared with those of the Malvern laser particle size analyzer to analyze the accuracy and optimize the ultrasonic spectrum cross-scale particle size distribution detection method.

[0022] Based on the same concept, the present invention also provides an ultrasonic spectrum cross-scale particle size distribution detection system, comprising:

[0023] The signal generation module is used to generate multiple sets of burst emission signals with different frequency ranges based on the pre-constructed linear frequency modulated signal constraints, which sequentially excite multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through the liquid under test, and record the excitation signal waveform and the received signal waveform.

[0024] The calculation module is used to calculate the amplitude information and attenuation coefficient of the received signal waveform at multiple different frequencies;

[0025] The results acquisition module is used to construct attenuation coefficients of different frequencies and form an observation array G, and to obtain the particle size distribution of the solid-liquid two-phase medium through an inversion algorithm.

[0026] Based on the same concept, the present invention also provides an electronic device, comprising:

[0027] The memory is used to store the processing program;

[0028] A processor, which, when executing the processing program, implements the ultrasonic spectrum cross-scale particle size distribution detection method described above.

[0029] Based on the same concept, the present invention also provides a readable storage medium storing a processing program, which, when executed by a processor, implements the ultrasonic spectrum cross-scale particle size distribution detection method described above.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] By arranging multiple transducers with different frequency bands into an array, broadband detection ranging from several kHz to tens of MHz is achieved, ultimately meeting the detection requirements for particle size scales from several micrometers to several millimeters. Using linear frequency modulated signals to excite the transmitting transducers at different frequency bands and demodulating the received frequency modulated signals separately, the amplitude of the received signals at different frequency bands can be calculated. This effectively shortens the detection time and is applicable to complex and variable multiphase flow processes, meeting the requirements for rapid measurement. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the composition of an ultrasonic spectrum cross-scale particle size distribution detection system as an example.

[0033] Figure 2 This is a schematic diagram of a burst sound emission signal according to an embodiment of the present invention. Detailed Implementation

[0034] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0035] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Furthermore, in the description of this application, "proximal" and "distal" are commonly used terms in the medical field. Specifically, "proximal" refers to the end closer to the operator, "proximal face" refers to the end face closer to the operator, "distal" refers to the end farther from the operator, and "distal face" refers to the end face farther from the operator.

[0037] Example

[0038] This embodiment provides a method for detecting cross-scale particle size distribution using ultrasonic spectra, applied to a detection system with multiple transducers of different driving frequency ranges, including:

[0039] Based on the pre-constructed linear frequency modulation signal constraint, multiple sets of burst sound emission signals with different frequency ranges are generated, which sequentially excite multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through the liquid under test, and record the excitation signal waveform and the received signal waveform.

[0040] Calculate the amplitude information and attenuation coefficient of the received signal waveform at multiple different frequencies;

[0041] Attenuation coefficients of different frequencies are constructed and formed into an observation array G. The particle size distribution of the solid-liquid two-phase medium is obtained through an inversion algorithm.

[0042] With the rapid development of particle-related fields such as energy, chemical engineering, electronics, machinery, materials preparation, food, and biomedicine, particle size distribution in two-phase flow has received increasing attention. Ultrasound, due to its high penetration capability, non-immersion nature, ease of online detection, simple equipment, and low cost, can achieve broadband detection from several kHz to tens of MHz by combining multiple transducers with different frequency bands in an array, ultimately meeting the detection requirements for particle size ranging from several micrometers to several millimeters. Using linear frequency modulated (LFM) signals to excite transmitting transducers at different frequency bands and demodulating the received LFM signals separately, the amplitude of the received signals at different frequency bands can be calculated, effectively shortening the detection time and making it suitable for complex and variable multiphase flow processes, meeting the requirements for rapid measurement. Using LFM signals to excite ultrasonic transducers can meet the requirements for rapid detection. Because the instantaneous frequency of a LFM signal changes linearly with time and has a wider spectrum than a single-frequency burst signal, ultrasonic excitation of different frequency ranges can be achieved within a shorter signal period, making it applicable to complex environments.

[0043] Preferably, the pre-constructed linear frequency modulation signal constraint formula is as follows:

[0044] Where B is the transducer bandwidth, T is the duration of the linear frequency modulated signal, f0 is the transducer's -6dB frequency lower limit, t is time, and w(t) is the window function.

[0045] In this embodiment, a formula for constructing a linear frequency modulated signal is provided. This formula can accurately generate multiple sets of burst emission signals with different frequency ranges. These signals are then transmitted to ultrasonic transducers in different frequency bands via an ultrasonic signal excitation device and transducer channels. The composition of the ultrasonic spectrum cross-scale particle size distribution detection system is described in [reference needed]. Figure 1(Taking five groups as an example), a multi-channel high-speed digital acquisition card (PXIe-5105) is connected to the five corresponding frequency band receiving transducers, and the data acquisition card is connected to the host (PC). Transmitting and receiving transducers with the same frequency band are placed facing each other. The -6dB bandwidth range of the transducers is 100kHz~300kHz, 500kHz~1MHz, 1MHz~3MHz, 5MHz~10MHz, and 10MHz~30MHz. The liquid phase in the test pipeline is water, and the solid phase is quartz sand. A magnetic stirrer is used to stir the solid-liquid two-phase medium in the test pipeline. After the medium is evenly mixed, the transmitting transducers can be excited. The ultrasonic signal excitation device is in linear frequency modulation mode, with a signal duration of 8µs, and sequentially excites the five groups of transmitting transducers with different frequency bands. The receiving transducers receive the frequency modulation signals emitted by the corresponding frequency band transducers, which are sampled by the multi-channel high-speed digital acquisition card and the data is uploaded to the PC.

[0046] Preferably, calculating the amplitude information of the received signal waveform at multiple different frequencies further includes:

[0047] Based on formula Calculate amplitude information at multiple different frequencies, where R d (w) represents the Fourier transform of the received burst signal at frequency ω, R c (w) represents the Fourier transform of the received linear frequency modulated signal, E d (w) represents the Fourier transform of the burst excitation signal at frequency ω, E c (w) represents the Fourier transform of the transmitted linear frequency modulated signal;

[0048] For R d (w) Perform inverse Fourier transform to obtain the amplitude of the received signal at different frequencies.

[0049] The PC demodulates the FM signal received by the transducer, using the demodulation reference formula. The MATLAB pseudocode for the burst emission signal is shown below, and the schematic diagram is as follows. Figure 2 As shown:

[0050] %Parameters

[0051] f = 300e3; % Sine wave frequency 300kHz

[0052] T = 5 / f; % Duration

[0053] fs = 2000 * f; % Sampling frequency

[0054] t = 0:1 / fs:T; % time

[0055] sinusoid = sin(2*pi*f*t);

[0056] window = hann(length(t))';

[0057] tone_burst = sinusoid.*window; % Construct a Hanning window sine wave

[0058] To balance analysis time and detection accuracy, three frequency points were selected for demodulation in each segment, and an attenuation coefficient observation array G was constructed. For the transmitting transducer with a -6dB bandwidth of 100kHz to 300kHz, 100kHz, 200kHz, and 300kHz were selected.

[0059] Preferably, calculating the attenuation coefficient of the received signal waveform at multiple different frequencies further includes:

[0060] Based on formula Calculate the attenuation coefficient α, where V R V E These are the received voltage values ​​in the liquid-solid two-phase medium and the received voltage value in the pure water medium at this frequency, respectively, and D is the distance between the transmitting and receiving transducers.

[0061] Preferably, attenuation coefficients of different frequencies are constructed and arranged into an observation array G, suitable for multi-scale, high- and low-concentration combined models. The attenuation coefficient A further includes:

[0062] G = [α] 1, α 2, α 3, α 4…, α n ] T ;

[0063] Three frequency points were selected for demodulation in each frequency range, and an attenuation coefficient observation array G was constructed.

[0064] Model A is constructed by combining the coupled phase model (Harker and Temple) HT and the BLBL analogous to the optical absorption law;

[0065] Inversion was performed using an inversion algorithm. The detection results of this embodiment were compared with those of the Malvern laser particle size analyzer, and the results showed an average correlation coefficient of 0.85.

[0066] Preferably, the frequency ranges of the generated burst emission signals of different frequency ranges are: 100kHz~300kHz, 500kHz~1MHz, 1MHz~3MHz, 5MHz~10MHz, and 10MHz~30MHz, respectively, and the duration of the burst emission signal is 8µs, which sequentially excite five sets of transmitting transducers of different frequency bands.

[0067] This embodiment employs an array of multiple transducers operating at different frequency bands to meet the broadband design requirements of 100kHz to 30MHz, enabling online detection of particle size distribution for particles ranging from 1μm to 3000μm in diameter. The transducers are arranged in a circle, with the transmitting transducer facing its corresponding receiving transducer to acquire attenuated signals.

[0068] Preferably, the method further includes:

[0069] The obtained particle size distribution results of the solid-liquid two-phase medium were compared with those of the Malvern laser particle size analyzer to analyze the accuracy and optimize the ultrasonic spectrum cross-scale particle size distribution detection method.

[0070] Based on the same concept, the present invention also provides an ultrasonic spectrum cross-scale particle size distribution detection system, comprising:

[0071] The signal generation module is used to generate multiple sets of burst emission signals with different frequency ranges based on the pre-constructed linear frequency modulated signal constraints, which sequentially excite multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through the liquid under test, and record the excitation signal waveform and the received signal waveform.

[0072] The calculation module is used to calculate the amplitude information and attenuation coefficient of the received signal waveform at multiple different frequencies;

[0073] The results acquisition module is used to construct attenuation coefficients of different frequencies and form an observation array G, and to obtain the particle size distribution of the solid-liquid two-phase medium through an inversion algorithm.

[0074] Because ultrasound has the advantages of high penetration capability, non-immersion, easy online detection, simple device, and low cost, by combining multiple transducers with different frequency ranges into an array, a broadband detection frequency range from several kHz to tens of MHz can be achieved, ultimately meeting the detection requirements of particle size range from several micrometers to several millimeters. Using linear frequency modulated signals to excite the transmitting transducers at different frequency bands and demodulating the received frequency modulated signals separately, the amplitude of the received signals at different frequency bands can be calculated, which can effectively shorten the detection time and is suitable for complex and variable multiphase flow processes, meeting the requirements for rapid measurement.

[0075] Based on the same concept, the present invention also provides an electronic device, comprising:

[0076] The memory is used to store the processing program;

[0077] A processor, which, when executing the processing program, implements the ultrasonic spectrum cross-scale particle size distribution detection method described above.

[0078] Based on the same concept, the present invention also provides a readable storage medium storing a processing program, which, when executed by a processor, implements the ultrasonic spectrum cross-scale particle size distribution detection method described above.

[0079] If the ultrasonic spectrum cross-scale particle size distribution detection method is implemented in the form of program instructions and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, essentially, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in software. This computer software is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0080] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific identification content executed by the system and device described above can be referred to the corresponding process in the foregoing method embodiments.

[0081] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A method for detecting cross-scale particle size distribution using ultrasonic spectra, applied to a detection system with multiple transducers of different driving frequency ranges, characterized in that, include: Based on the pre-constructed linear frequency modulation signal constraint, multiple sets of burst sound emission signals with different frequency ranges are generated, which sequentially excite multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through the liquid under test, and record the received signals passing through pure water and the liquid under test. Calculate the amplitude information and attenuation coefficient of the received signal waveform at multiple different frequencies; Attenuation coefficients at different frequencies are constructed and arranged into an observation array G. A theoretical model matrix A is constructed by combining the coupled phase model HT and the BLBL analogous to the optical absorption law. Inversion is performed by calculating the following equation: AF = G Obtain the particle size distribution F of the solid-liquid two-phase medium.

2. The ultrasonic spectrum cross-scale particle size distribution detection method as described in claim 1, characterized in that, The pre-constructed constraint formula for the linear frequency modulated signal is: Where B is the transducer bandwidth, T is the duration of the linear frequency modulated signal, f0 is the transducer's -6dB frequency lower limit, t is time, and w(t) is the window function.

3. The ultrasonic spectrum cross-scale particle size distribution detection method as described in claim 1, characterized in that, Calculating the amplitude information of the received signal waveform at multiple different frequencies further includes: Based on formula Calculate amplitude information at multiple different frequencies, where R d (w) represents the Fourier transform of the received burst signal at frequency ω, R c (w) represents the Fourier transform of the received linear frequency modulated signal, E d (w) represents the Fourier transform of the burst excitation signal at frequency ω, E c (w) represents the Fourier transform of the transmitted linear frequency modulated signal; For R d (w) Perform inverse Fourier transform to obtain the amplitude of the received signal at different frequencies.

4. The ultrasonic spectrum cross-scale particle size distribution detection method as described in claim 3, characterized in that, Calculating the attenuation coefficient of the received signal waveform at multiple different frequencies further includes: Based on formula Calculate the attenuation coefficient α, where V R V E These are the received voltage values ​​in the liquid-solid two-phase medium and the received voltage value in the pure water medium at this frequency, respectively, and D is the distance between the transmitting and receiving transducers.

5. The ultrasonic spectrum cross-scale particle size distribution detection method as described in claim 1, characterized in that, Attenuation coefficients of different frequencies are constructed and formed into an observation array G. The theoretical model matrix A is constructed by combining the coupled phase model HT and the BLBL analogous to the optical absorption law. When using AF=G to invert and obtain the particle size distribution F of the solid-liquid two-phase medium, three frequency points are selected for demodulation in each frequency range and an attenuation coefficient observation array G is constructed.

6. The ultrasonic spectrum cross-scale particle size distribution detection method as described in claim 2, characterized in that, The generated burst emission signals have frequency ranges of 100kHz~300kHz, 500kHz~1MHz, 1MHz~3MHz, 5MHz~10MHz, and 10MHz~30MHz, respectively. The duration of the burst emission signal is 8µs, which sequentially excite five sets of transmitting transducers in different frequency bands.

7. The ultrasonic spectrum cross-scale particle size distribution detection method as described in claim 1, characterized in that, The method further includes: The obtained particle size distribution results of the solid-liquid two-phase medium were compared with those of the Malvern laser particle size analyzer to analyze the accuracy and optimize the ultrasonic spectrum cross-scale particle size distribution detection method.

8. A transscale particle size distribution detection system using ultrasonic spectroscopy, characterized in that, include: The signal generation module is used to generate multiple sets of burst emission signals with different frequency ranges based on the pre-constructed linear frequency modulated signal constraints, which sequentially excite multiple transducers to emit ultrasonic waves and receive ultrasonic waves passing through the liquid under test, and record the excitation signal waveform and the received signal waveform. The calculation module is used to calculate the amplitude information and attenuation coefficient of the received signal waveform at multiple different frequencies; The results acquisition module is used to construct attenuation coefficients of different frequencies and form an observation array G, and to obtain the particle size distribution of the solid-liquid two-phase medium through an inversion algorithm.

9. An electronic device, characterized in that, include: The memory is used to store the processing program; A processor, which, when executing the processing program, implements the ultrasonic spectrum cross-scale particle size distribution detection method according to any one of claims 1-7.

10. A readable storage medium, characterized in that, The readable storage medium stores a processing program, which, when executed by a processor, implements the ultrasonic spectrum cross-scale particle size distribution detection method according to any one of claims 1-7.

Images