Signal processing method and device, computer readable storage medium and computer device

Abstract

The application discloses a signal processing method and device, a computer readable storage medium and computer equipment. The method comprises the following steps: multiple ultrasonic sensing probes are used to measure a target medium at a target position of the target medium, and multiple narrow-band ultrasonic signals are obtained; the multiple narrow-band ultrasonic signals are aligned and corrected according to time, and multiple target narrow-band ultrasonic signals are obtained; multiple signal conversion relationships corresponding to the multiple ultrasonic sensing probes are determined; and the multiple target narrow-band ultrasonic signals are converted based on the multiple signal conversion relationships, and a target time-domain waveform corresponding to the target medium is obtained. The application solves the technical problems of inaccurate space charge measurement results for insulating media and information loss of ultrasonic signals in the measurement process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ultrasonic signal measurement, and in particular, to a signal processing method and device, a computer readable storage medium and a computer device. BACKGROUND

[0002] In the related art, when measuring the space charge of an insulating medium, the measurement result is usually inaccurate, and the measured ultrasonic signal has a signal loss.

[0003] To address the above problems, no effective solutions have been proposed so far. SUMMARY

[0004] The embodiments of the present application provide a signal processing method and device, a computer readable storage medium and a computer device to at least solve the technical problems of inaccurate space charge measurement result of an insulating medium and information loss of ultrasonic signal in the measurement process.

[0005] According to an aspect of the embodiments of the present application, a signal processing method is provided, including: measuring a target medium at a target position of the target medium by using a plurality of ultrasonic sensing probes to obtain a plurality of narrow-band ultrasonic signals; aligning and correcting the plurality of narrow-band ultrasonic signals according to time to obtain a plurality of target narrow-band ultrasonic signals; determining a plurality of signal conversion relationships corresponding to the plurality of ultrasonic sensing probes respectively; and converting the plurality of target narrow-band ultrasonic signals based on the plurality of signal conversion relationships to obtain a target time-domain waveform corresponding to the target medium.

[0006] Optionally, the measurement frequency ranges of the plurality of ultrasonic sensing probes are different, and the union of the measurement frequency ranges of the plurality of ultrasonic sensing probes is a target measurement frequency range of the target medium.

[0007] Optionally, aligning and correcting the plurality of narrow-band ultrasonic signals according to time to obtain the plurality of target narrow-band ultrasonic signals includes: obtaining a measurement angle between an ultrasonic propagation trajectory of the plurality of ultrasonic sensing probes and a measurement plane at the target position during the measurement of the target medium by the plurality of ultrasonic sensing probes according to a predetermined movement trajectory; and aligning and correcting the plurality of narrow-band ultrasonic signals according to time based on the measurement angle to obtain the plurality of target narrow-band ultrasonic signals.

[0008] Optionally, aligning and correcting the plurality of narrow-band ultrasonic signals according to time based on the measurement angle to obtain the plurality of target narrow-band ultrasonic signals includes at least one of:

[0009] When the measurement angle is perpendicular, the reception time points of the ultrasonic reflection signals in multiple narrow-band ultrasonic signals are determined, and the multiple narrow-band ultrasonic signals are aligned and corrected according to the reception time points of the ultrasonic reflection signals to obtain multiple target narrow-band ultrasonic signals. When the measurement angle is non-perpendicular, multiple electrostriction signals generated by the electrostriction force of the target medium during the measurement process of multiple ultrasonic sensing probes are acquired, and the multiple electrostriction signals are used as reference signals to align and correct multiple narrow-band ultrasonic signals to obtain multiple target narrow-band ultrasonic signals.

[0010] Optionally, the various signal conversion relationships corresponding to the multiple ultrasonic sensing probes are determined, including: acquiring the pulse voltage waveforms of the pulse voltages of the multiple ultrasonic sensing probes during the measurement process; measuring the ultrasonic wave shape of the plate electrode made of the target medium using the multiple ultrasonic sensing probes to obtain the multiple plate electrode ultrasonic wave shapes corresponding to the multiple ultrasonic sensing probes; and determining the various signal conversion relationships corresponding to the multiple ultrasonic sensing probes based on the pulse voltage waveforms and the multiple plate electrode ultrasonic wave shapes.

[0011] Optionally, based on multiple signal conversion relationships, multiple target narrowband ultrasonic signals are converted to obtain target time-domain waveforms corresponding to the target medium, including: acquiring multiple measurement frequency ranges corresponding to multiple ultrasonic sensing probes; determining broadband ultrasonic signals corresponding to multiple target narrowband ultrasonic signals based on multiple signal conversion relationships and multiple measurement frequency ranges corresponding to multiple ultrasonic sensing probes; and determining the time-domain waveform of the broadband ultrasonic signal as the target time-domain waveform corresponding to the target medium.

[0012] Optionally, multiple signal conversion relationships are used to achieve at least one of the following signal conversions: time delay conversion during signal propagation, conversion between acoustic pressure and measured voltage in a signal, signal preprocessing conversion, conversion from frequency domain waveform to time domain waveform, and synthesis conversion of multiple signals.

[0013] According to another aspect of the present invention, a signal processing apparatus is also provided, comprising: a measurement module for performing multiple measurements on a target medium at a target location using multiple ultrasonic sensing probes to obtain multiple narrowband ultrasonic signals; a correction module for aligning and correcting the multiple narrowband ultrasonic signals according to time to obtain multiple target narrowband ultrasonic signals; a determination module for determining multiple signal conversion relationships corresponding to the multiple ultrasonic sensing probes; and a conversion module for converting the multiple target narrowband ultrasonic signals based on the multiple signal conversion relationships to obtain a target time-domain waveform corresponding to the target medium.

[0014] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the signal processing method described above.

[0015] According to another aspect of the present invention, a computer device is also provided, comprising: a memory and a processor, the memory storing a computer program; and a processor for executing the computer program stored in the memory, wherein the computer program, when running, causes the processor to perform the signal processing method described above.

[0016] In this embodiment of the invention, multiple ultrasonic sensing probes with different measurement frequency ranges are used to perform multiple measurements at the target location of the target medium. By aligning and correcting the multiple ultrasonic signals obtained by time using ultrasonic reflection signals or electrostriction signals, the time offset of the ultrasonic signals is reduced. At the same time, by using multiple ultrasonic sensing probes with different measurement frequency ranges and employing signal conversion relationships, the ultrasonic signals with the originally narrow measurement frequency range are integrated into an ultrasonic signal with a wider measurement frequency range. This avoids the loss of ultrasonic information at low or high frequencies when measuring the space charge of the target medium. Thus, the technical effect of improving the accuracy of the space charge measurement results for the target medium is achieved by reducing the time offset of the ultrasonic signal and avoiding the loss of ultrasonic information. This solves the technical problems of inaccurate space charge measurement results for insulating media and the information loss of ultrasonic signals during the measurement process. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a flowchart of a signal processing method provided according to an embodiment of the present invention;

[0019] Figure 2 These are received spectrum diagrams of different probes provided according to optional embodiments of the present invention;

[0020] Figure 3 This is a schematic diagram of the measured waveform of the ultrasonic sensing probe provided according to an optional embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of ultrasonic measurement provided according to an optional embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of an unaligned waveform provided by an optional embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the alignment waveform provided by an optional embodiment of the present invention;

[0024] Figure 7a This is a schematic diagram of a 1MHz probe measurement waveform provided according to an optional embodiment of the present invention;

[0025] Figure 7b This is a schematic diagram of a 5MHz probe measurement waveform provided according to an optional embodiment of the present invention;

[0026] Figure 7c This is a schematic diagram of a 10MHz probe measurement waveform provided according to an optional embodiment of the present invention;

[0027] Figure 7d This is a schematic diagram of a synthesized measurement waveform provided by an optional embodiment of the present invention;

[0028] Figure 8 This is a structural block diagram of a signal processing device provided according to an embodiment of the present invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] According to an embodiment of the present invention, a method embodiment for signal processing is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0032] Figure 1 This is a flowchart of a signal processing method provided according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0033] Step S102: At the target location of the target medium, multiple ultrasonic sensing probes are used to perform multiple measurements on the target medium to obtain multiple narrowband ultrasonic signals.

[0034] Step S104: Align and correct multiple narrowband ultrasonic signals according to time to obtain multiple target narrowband ultrasonic signals;

[0035] Step S106: Determine the various signal conversion relationships corresponding to the multiple ultrasonic sensing probes respectively;

[0036] Step S108: Based on multiple signal conversion relationships, convert multiple target narrowband ultrasonic signals respectively to obtain the target time-domain waveform corresponding to the target medium.

[0037] Through the above steps, multiple ultrasonic sensing probes with different measurement frequency ranges can be used to perform multiple measurements at the target location of the target medium. By aligning and correcting the multiple ultrasonic signals obtained from the measurements using ultrasonic reflection signals or electrostriction signals according to time, the time offset of the ultrasonic signals is reduced. At the same time, by using multiple ultrasonic sensing probes with different measurement frequency ranges and employing signal conversion relationships, the ultrasonic signals originally measured with a narrow measurement frequency range are integrated into an ultrasonic signal with a wider measurement frequency range. This avoids the loss of ultrasonic information at low or high frequencies when measuring the space charge of the target medium. Thus, the technical effect of improving the accuracy of the space charge measurement results for the target medium is achieved by reducing the time offset of the ultrasonic signal and avoiding the loss of ultrasonic information. This solves the technical problems of inaccurate space charge measurement results for insulating media and the information loss of ultrasonic signals during the measurement process.

[0038] As an optional embodiment, multiple ultrasonic sensing probes have different measurement frequency ranges, and the union of the measurement frequency ranges of multiple ultrasonic sensing probes is the target measurement frequency range of the target medium. In this embodiment of the invention, the frequency range to be measured for the target medium can be divided, and ultrasonic sensing probes with different measurement frequency ranges can be selected based on the frequency range division results. For example, if it is necessary to measure the ultrasonic signal of the target medium in the frequency range of [0Hz, 15MHz], the frequency range can be divided into [0Hz, 2MHz), [2Hz, 8MHz), and [8Hz, 15MHz]. Then, based on the above frequency range division results, three ultrasonic sensing probes with center frequencies of 1MHz, 5MHz, and 10MHz can be selected. Thus, by using ultrasonic sensing probes with different measurement frequency ranges, the ultrasonic signal of the target medium in the required frequency range can be completely measured, thereby avoiding the loss of ultrasonic information at low or high frequencies.

[0039] As an optional embodiment, multiple narrowband ultrasonic signals are aligned and corrected according to time to obtain multiple target narrowband ultrasonic signals, including: during the process of multiple ultrasonic sensing probes measuring the target medium according to a predetermined moving trajectory, obtaining the measurement angle between the ultrasonic propagation trajectory of the multiple ultrasonic sensing probes and the measurement plane at the target position; based on the measurement angle, the multiple narrowband ultrasonic signals are aligned and corrected according to time to obtain multiple target narrowband ultrasonic signals.

[0040] The time information of the signal obtained from measuring space charge includes the position information of the space charge. However, when using a pulse voltage signal as the trigger source, the measured ultrasonic signal will have a time offset problem, which will lead to inaccurate space charge measurement results. In this embodiment of the invention, the ultrasonic sensing probe emits ultrasonic signals from different angles relative to the measurement plane at the target position according to a predetermined movement trajectory to measure the space charge at the target position of the target medium. During the movement of the ultrasonic sensing probe, the propagation trajectory of the emitted ultrasonic signal will be at different measurement angles with the measurement plane at the target position. According to this embodiment of the invention, different alignment correction methods can be used for the measured ultrasonic signal according to the measurement angle.

[0041] As an optional embodiment, multiple narrowband ultrasonic signals are aligned and corrected according to time to obtain multiple target narrowband ultrasonic signals, including at least one of the following: when the measurement angle is vertical, the receiving time point of the ultrasonic reflection signal in the multiple narrowband ultrasonic signals is determined respectively, and the multiple narrowband ultrasonic signals are aligned and corrected according to the receiving time point of the ultrasonic reflection signal to obtain multiple target narrowband ultrasonic signals; when the measurement angle is not vertical, multiple electrostriction signals generated by the electrostriction force of the target medium by multiple ultrasonic sensing probes during the measurement process are acquired respectively, and the multiple electrostriction signals are used as reference signals to align and correct the multiple narrowband ultrasonic signals to obtain multiple target narrowband ultrasonic signals.

[0042] When the measurement angle is vertical, the ultrasonic sensing probe will receive a large ultrasonic reflection signal reflected back from the measurement plane, and the receiving time of the ultrasonic reflection signal will not be affected by electromagnetic interference. Therefore, in this embodiment of the invention, the receiving time of the ultrasonic reflection signal is used to align multiple narrow-band ultrasonic signals to reduce the time offset of the ultrasonic signal.

[0043] When the measurement angle is not perpendicular, the ultrasonic reflection signal received by the ultrasonic sensing probe is relatively small. Therefore, in this case, embodiments of the present invention use an electrostrictive signal to align multiple narrow-band ultrasonic signals. The electrostrictive signal corresponds to the electrostrictive force in the target medium, which depends only on the target medium and does not change over time. Therefore, the electrostrictive signal corresponding to the electrostrictive force of the target medium can be used as a reference signal to align multiple narrow-band ultrasonic signals in time. For example, multiple narrow-band ultrasonic signals can be aligned according to the peak value of the electrostrictive signal, and so on.

[0044] As an optional embodiment, determining multiple signal conversion relationships corresponding to multiple ultrasonic sensing probes includes: acquiring the pulse voltage waveforms of the pulse voltages of the multiple ultrasonic sensing probes during the measurement process; measuring the ultrasonic wave shape of a plate electrode made of a target medium using the multiple ultrasonic sensing probes to obtain multiple plate electrode ultrasonic wave shapes corresponding to the multiple ultrasonic sensing probes; and determining multiple signal conversion relationships corresponding to the multiple ultrasonic sensing probes based on the pulse voltage waveforms and the multiple plate electrode ultrasonic wave shapes.

[0045] The ultrasonic waveform of the plate electrode, measured by an ultrasonic sensor probe on a plate electrode made of the target medium, is the same as the pulse voltage waveform measured by the ultrasonic sensor probe during the measurement process. They differ only by a coefficient. By measuring these two waveforms separately using the ultrasonic sensor probe, the coefficient corresponding to each ultrasonic sensor probe can be determined. Based on the determination of this coefficient, various signal conversion relationships corresponding to each ultrasonic sensor probe can be determined, so as to convert multiple target narrowband ultrasonic signals into the target time-domain waveform of the target medium.

[0046] As an optional embodiment, multiple target narrowband ultrasonic signals are converted based on various signal conversion relationships to obtain target time-domain waveforms corresponding to the target medium. This includes: acquiring multiple measurement frequency ranges corresponding to multiple ultrasonic sensing probes; determining broadband ultrasonic signals corresponding to the multiple target narrowband ultrasonic signals based on various signal conversion relationships and multiple measurement frequency ranges corresponding to the multiple ultrasonic sensing probes; and determining the time-domain waveform of the broadband ultrasonic signal as the target time-domain waveform corresponding to the target medium.

[0047] The frequency range of ultrasonic signals directly measured by ultrasonic sensing probes is relatively small. In this embodiment of the invention, multiple ultrasonic sensing probes with different measurement frequency ranges are used, and the union of the measurement frequency ranges of different ultrasonic sensing probes is the frequency range that needs to be measured for the target medium. Therefore, after measuring multiple narrow-band ultrasonic signals, the multiple narrow-band ultrasonic signals can be synthesized and converted into broadband ultrasonic signals according to their corresponding measurement frequency ranges. The broadband ultrasonic signal is the target time-domain waveform that needs to be measured, so as to retain the ultrasonic information of the target medium in the low-frequency and high-frequency parts.

[0048] As an optional embodiment, various signal conversion relationships are used to achieve at least one of the following signal conversions: time delay conversion of signal during propagation, conversion of acoustic pressure in a signal to measured voltage, signal preprocessing conversion, conversion of frequency domain waveform to time domain waveform, and synthesis conversion of multiple signals.

[0049] Based on the above embodiments and optional embodiments, the present invention proposes an optional implementation method, which will be described below.

[0050] Space charge measurement within solid insulating media is an important method for evaluating the performance of insulating materials in the field of high-voltage insulation. When measuring space charge based on the principle of electroacoustic pulse method, it is necessary to measure the ultrasonic signal generated by charge vibration to infer the charge distribution.

[0051] However, the measurement system contains a pulse power supply, which provides pulse voltage for space charge measurement. This pulse power supply generates electromagnetic interference during operation, severely affecting the ultrasonic sensor's measurements. Furthermore, the pulse voltage generated by the pulse generator exhibits some fluctuation; since a pulse voltage signal is used as the trigger source, the ultrasonic measurement signal will have a certain degree of time offset. According to space charge measurement theory, the time information of the ultrasonic signal contains the positional information of the space charge. If this time offset is not addressed, it will directly lead to inaccurate space charge measurement results. Therefore, repeated ultrasonic signal measurements at the same location require a method to achieve ultrasonic wave shape position calibration.

[0052] Meanwhile, the ultrasonic sensors used in the measurements need to be easily movable and conveniently placed in different locations for ultrasonic measurements. Therefore, ultrasonic transducer probes or hydrophone probes are generally selected. However, the problem with these probes is that the bandwidth of a single probe is limited. Figure 2 These are received spectrum diagrams of different probes provided according to optional embodiments of the present invention, such as... Figure 2 As shown, when using a single ultrasonic sensor probe to measure broadband ultrasound, some low-frequency or high-frequency ultrasonic information will inevitably be lost.

[0053] The optional embodiments of the present invention propose corresponding measurement methods and data processing methods to address the problems existing in the two-dimensional space charge measurement process in the above-mentioned related technologies.

[0054] An optional embodiment of this invention proposes a time calibration method for multiple measurements at the same location using reflected ultrasonic signals and electrostriction signals as references, ensuring that the ultrasonic signals measured at the same location correspond in time. Simultaneously, this optional embodiment uses multiple ultrasonic sensing probes to simultaneously measure and calculate the waveform of the actual broadband ultrasonic signal, thus addressing the problem of a narrow detection frequency range for a single ultrasonic sensing probe. The optional embodiments of this invention are described in detail below.

[0055] First, the ultrasonic sensor probe is subject to significant electromagnetic interference during measurement, mainly due to the operation of the pulse power supply. Figure 3 This is a schematic diagram of the measured waveform of the ultrasonic sensing probe provided by an optional embodiment of the present invention, such as... Figure 3 As shown, the waveform measured by the probe has a large range of interference fluctuations, while the real ultrasonic signal exists on the interference waveform. Then, it is divided into two parts: ultrasonic reflection signal and charge ultrasonic signal. Figure 4 This is a schematic diagram of ultrasonic measurement provided according to an optional embodiment of the present invention, such as... Figure 4As shown, the ultrasonic sensor probe is affected by electromagnetic interference during the measurement process, and the propagation time of electromagnetic interference in space is negligible. Therefore, at the instant data acquisition is triggered, the ultrasonic sensor probe excites and emits an ultrasonic signal generated by electromagnetic interference, which is reflected at the sample interface and then received by the ultrasonic sensor probe; this is the ultrasonic reflected signal, denoted as t1. Additionally, an ultrasonic signal of charge is transmitted from inside the sample and received by the ultrasonic sensor probe; this is denoted as the charge ultrasonic signal, denoted as t2. Due to the ultrasonic propagation path, the occurrence times of the two signals satisfy the following relationship:

[0056] t1 = 2 × t2

[0057] The relationship shown in the above equation is determined by the ultrasonic propagation path and will not be altered by electromagnetic interference. Therefore, by aligning the ultrasonic reflection signals of repeated measurements, time-correspondence processing of the effective signal can be achieved.

[0058] When the ultrasonic sensing probe is directly below the sample, the received ultrasonic reflected signal is relatively large, making the above method convenient. However, when the ultrasonic sensing probe moves along the measurement path and is no longer directly below the sample, the above method becomes difficult to apply. In this case, an optional embodiment of the present invention utilizes the ultrasonic wave generated by electrostrictive force for alignment. Because the electrical field inside the sample is non-uniform, it contains electrostrictive force.

[0059]

[0060] The electric field distribution characteristics show that the electrostrictive force is greatest at the tip electrode surface; therefore, the peak position of the electrostrictive force is the position of the tip electrode. Furthermore, the electrostrictive force does not change over time, so the ultrasonic signal generated by this force can be used as a reference for time alignment of the charge-ultrasonic signal.

[0061] To address the problem of measuring effective ultrasonic signal waveforms, Figure 2 The measurement using the three probes shown is an example. Probes with center frequencies of 1MHz, 5MHz, and 10MHz are denoted as PZT1, PZT2, and PZT3, respectively. The number of probes and their parameters can be selected according to the actual situation, with the goal of covering the required frequency range.

[0062] First, a predicted quantity of the charge ultrasonic signal is calculated to extract the transfer function of each probe. For a solid insulating dielectric sample with a needle-plate electrode, a surface charge σ0 is induced on the plate electrode when a DC voltage is applied. Simultaneously, the applied pulse voltage induces an electric field on the plate electrode perpendicular to the plate electrode direction, denoted as e(t). Therefore, the force on the plate electrode is as follows:

[0063] f s =σ0e(t)

[0064] This time-varying force induces the generation of ultrasound within the electrode, denoted as a(t). The relationship between the generated ultrasound and the electric field and charge in the frequency domain is as follows:

[0065] A(f) = KE(f)

[0066] The ultrasonic wave generated by the plate electrode has the same waveform as the applied pulse excitation, differing only by a coefficient. The waveform of the pulse voltage can be measured using a high-voltage probe, thus the waveform of the ultrasonic signal at the plate electrode can be predicted. Therefore, it can be used as a reference sound source to obtain the probe's transfer function. The waveforms measured by the three probes are denoted as P1(t), P2(t), and P3(t), respectively. The transfer function of each ultrasonic sensing probe can be expressed as follows:

[0067]

[0068] Since each ultrasonic sensor probe covers a different frequency range, the measurement frequency range of each probe is divided according to its own frequency band and the frequency range of the signal to be measured. This ensures that the union of the three divided frequency bands covers the frequency range of the signal to be measured, and that the three divided frequency bands do not overlap. For example, here, PZT1, PZT2, and PZT3 are selected to measure frequency ranges of [0Hz, 2MHz), [2Hz, 8MHz), and [8Hz, 15MHz], respectively.

[0069] Then, three ultrasonic sensing probes were used to measure the ultrasound under test. Let the measured sound wave signals be: P 1s (t), P 2s (t) and P 3s (t), the ultrasonic waveform to be measured can be obtained by using the formula for the time relationship between the charged ultrasonic signal and the ultrasonic reflection signal, as expressed below:

[0070] V(t)=F -1 [P 1s (f) / T1(f)| [0Hz，2MHz) +P 2s (f) / T2(f)| [2Hz，8MHz) +P 3s (f) / T3(f)| [8Hz，15MHz] ]

[0071] Therefore, the measurement of broadband ultrasonic signals can be achieved using multiple ultrasonic sensing probes with limited frequency measurement ranges. The specific steps are summarized as follows:

[0072] 1. First, select several ultrasonic sensing probes with different frequency ranges according to the approximate probability range of the ultrasonic signal to be measured. The union of the measurement frequency ranges of these probes should be able to cover the frequency range of the ultrasonic signal to be measured.

[0073] 2. Measure the pulse voltage waveform;

[0074] 3. Measure the ultrasonic wave shape generated by the plate electrode using each ultrasonic sensor probe and use this to determine the transfer function;

[0075] 4. Divide the measurement frequency range of each ultrasonic sensor probe according to the measurement frequency band of each probe, so that it can just cover the frequency range of the signal to be measured.

[0076] 5. Measure the signal to be tested using each ultrasonic sensor probe. Since the frequency range of a single probe is limited, each measured waveform obtained at this time will have missing frequency parts. Using the transfer function obtained in step 3 and the frequency range divided in step 4, the time domain waveform of the broadband ultrasonic signal to be tested can be deduced from the above ultrasonic waveform formula.

[0077] Taking data from an actual measurement process as an example, Figure 5 This is a schematic diagram of an unaligned waveform provided by an optional embodiment of the present invention. Figure 6 This is a schematic diagram of the aligned waveform provided by an optional embodiment of the present invention. If the ultrasonic signal of the charge to be measured is directly transferred from... Figure 3 If extracted from the measured waveform shown, the result will be as follows: Figure 5 The waveforms shown demonstrate that electromagnetic interference and the fluctuations in the pulse generator cause the repetitive waveforms to be out of sync in time. After processing, the waveforms can be obtained as follows: Figure 6 The waveform shown.

[0078] like Figure 6 As shown, the waveform of the more obvious undulating part at the beginning is the ultrasonic wave generated on the plate electrode, so its position does not change much. However, the undulating part at the end has a larger change in ultrasonic wave due to the greater charge injection. Only after the alignment operation can the waveforms be correctly compared and the space charge injection situation be observed.

[0079] Using the ultrasonic wave pattern generated by a flat plate electrode as a reference, a certain waveform was measured using ultrasonic sensing probes with center frequencies of 1MHz, 5MHz, and 10MHz. Figure 7a This is a schematic diagram of a 1MHz probe measurement waveform provided according to an optional embodiment of the present invention. Figure 7b This is a schematic diagram of a 5MHz probe measurement waveform provided according to an optional embodiment of the present invention. Figure 7cThis is a schematic diagram of a 10MHz probe measurement waveform provided according to an optional embodiment of the present invention. The measurement results are as follows: Figure 7a , Figure 7b and Figure 7c As shown, Figure 7d This is a schematic diagram of a synthesized measurement waveform provided by an optional embodiment of the present invention. Given the transfer function, waveform splicing in the frequency domain yields a result such as... Figure 7d The waveform shown.

[0080] According to embodiments of the present invention, a signal processing apparatus is also provided. Figure 8 This is a structural block diagram of a signal processing apparatus provided according to an embodiment of the present invention, such as... Figure 8 As shown, the device includes: a measurement module 81, a calibration module 82, a determination module 83, and a conversion module 84. The device will be described below.

[0081] Measurement module 81 is used to perform multiple measurements on the target medium at the target location using multiple ultrasonic sensing probes to obtain multiple narrowband ultrasonic signals; correction module 82, connected to the measurement module 81, is used to align and correct the multiple narrowband ultrasonic signals according to time to obtain multiple target narrowband ultrasonic signals; determination module 83, connected to the correction module 82, is used to determine multiple signal conversion relationships corresponding to the multiple ultrasonic sensing probes; conversion module 84, connected to the determination module 83, is used to convert the multiple target narrowband ultrasonic signals based on the multiple signal conversion relationships to obtain target time-domain waveforms corresponding to the target medium.

[0082] According to an embodiment of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is running, it controls the device where the computer-readable storage medium is located to execute the signal processing method described above.

[0083] According to an embodiment of the present invention, a computer device is also provided, comprising: a memory and a processor, wherein the memory stores a computer program; and the processor is configured to execute the computer program stored in the memory, wherein the computer program, when running, causes the processor to perform any of the signal processing methods described above.

[0084] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0085] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0086] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0087] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0088] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0089] If the integrated unit is implemented as a software functional unit 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 the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product 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 the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0090] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A signal processing method, characterized in that, include: Multiple ultrasonic sensing probes are used to measure the target medium multiple times at the target location to obtain multiple narrowband ultrasonic signals. The multiple narrowband ultrasonic signals are aligned and corrected according to time to obtain multiple target narrowband ultrasonic signals; Determine the various signal conversion relationships corresponding to the multiple ultrasonic sensing probes respectively; Based on the aforementioned signal conversion relationships, the multiple target narrowband ultrasonic signals are converted to obtain the target time-domain waveform corresponding to the target medium. The step of aligning and correcting the multiple narrowband ultrasonic signals according to time to obtain multiple target narrowband ultrasonic signals includes: during the process of the multiple ultrasonic sensing probes measuring the target medium according to a predetermined moving trajectory, acquiring the measurement angle between the ultrasonic propagation trajectory of the multiple ultrasonic sensing probes and the measurement plane at the target position; and based on the measurement angle, aligning and correcting the multiple narrowband ultrasonic signals according to time to obtain multiple target narrowband ultrasonic signals. The step of aligning and correcting the multiple narrowband ultrasonic signals according to time based on the measurement angle to obtain multiple target narrowband ultrasonic signals includes at least one of the following: when the measurement angle is a vertical angle, determining the reception time point of the ultrasonic reflection signal in the multiple narrowband ultrasonic signals respectively, and aligning and correcting the multiple narrowband ultrasonic signals according to the reception time point of the ultrasonic reflection signal to obtain multiple target narrowband ultrasonic signals; when the measurement angle is not a vertical angle, acquiring multiple electrostriction signals generated by the electrostriction force of the target medium by the multiple ultrasonic sensing probes during the measurement process, and using the multiple electrostriction signals as reference signals to align and correct the multiple narrowband ultrasonic signals to obtain multiple target narrowband ultrasonic signals.

2. The method according to claim 1, characterized in that, The multiple ultrasonic sensing probes have different measurement frequency ranges, and the union of the measurement frequency ranges of the multiple ultrasonic sensing probes is the target measurement frequency range of the target medium.

3. The method according to claim 1, characterized in that, The determination of the various signal conversion relationships corresponding to the plurality of ultrasonic sensing probes includes: Acquire the pulse voltage waveform of the multiple ultrasonic sensing probes during the measurement process; The ultrasonic waveforms of the planar electrodes made of the target medium are measured using the multiple ultrasonic sensing probes respectively, thereby obtaining the multiple planar electrode ultrasonic waveforms corresponding to the multiple ultrasonic sensing probes respectively. Based on the pulse voltage waveform and the ultrasonic waveform of the multiple planar electrodes, the various signal conversion relationships corresponding to the multiple ultrasonic sensing probes are determined respectively.

4. The method according to claim 1, characterized in that, The process of converting the multiple target narrowband ultrasonic signals based on the aforementioned signal conversion relationships to obtain the target time-domain waveform corresponding to the target medium includes: Obtain the multiple measurement frequency ranges corresponding to the multiple ultrasonic sensing probes respectively; Based on the various signal conversion relationships and the various measurement frequency ranges corresponding to the multiple ultrasonic sensing probes, the broadband ultrasonic signals corresponding to the multiple target narrowband ultrasonic signals are determined. The time-domain waveform of the broadband ultrasonic signal is determined as the target time-domain waveform corresponding to the target medium.

5. The method according to any one of claims 1 to 4, characterized in that, The various signal conversion relationships are used to achieve at least one of the following signal conversions: Signal propagation time delay conversion, conversion between acoustic pressure and measured voltage in a signal, signal preprocessing conversion, conversion from frequency domain waveform to time domain waveform, and synthesis conversion of multiple signals.

6. A signal processing apparatus, characterized in that, include: The measurement module is used to perform multiple measurements on the target medium at the target location using multiple ultrasonic sensing probes to obtain multiple narrowband ultrasonic signals. The correction module is used to perform time-aligned correction on the multiple narrowband ultrasonic signals to obtain multiple target narrowband ultrasonic signals; The determination module is used to determine the various signal conversion relationships corresponding to the plurality of ultrasonic sensing probes respectively; The conversion module is used to convert the multiple target narrowband ultrasonic signals based on the multiple signal conversion relationships to obtain the target time-domain waveform corresponding to the target medium. The correction module is further configured to acquire the measurement angle between the ultrasonic propagation trajectory of the multiple ultrasonic sensing probes and the measurement plane at the target position during the process of the multiple ultrasonic sensing probes measuring the target medium according to a predetermined moving trajectory; and based on the measurement angle, to perform time-aligned correction on the multiple narrowband ultrasonic signals to obtain multiple target narrowband ultrasonic signals. The correction module is further configured to: determine the reception time point of the ultrasonic reflection signal in the plurality of narrowband ultrasonic signals when the measurement angle is perpendicular; and perform alignment correction on the plurality of narrowband ultrasonic signals according to the reception time point of the ultrasonic reflection signal to obtain a plurality of target narrowband ultrasonic signals; and acquire a plurality of electrostriction signals generated by the electrostriction force of the target medium by the plurality of ultrasonic sensing probes during the measurement process when the measurement angle is non-perpendicular; and use the plurality of electrostriction signals as reference signals to perform alignment correction on the plurality of narrowband ultrasonic signals to obtain a plurality of target narrowband ultrasonic signals.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the signal processing method according to any one of claims 1 to 5.

8. A computer device, characterized in that, include: Memory and processor The memory stores computer programs; The processor is configured to execute a computer program stored in the memory, wherein when the computer program is executed, the processor performs the signal processing method according to any one of claims 1 to 5.

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