Transducer control method and ultrasonic system

Abstract

The invention provides a transducer control method and an ultrasonic system. The method comprises the following steps: sending excitation sources with different frequencies to a transmitting end transducer, so that the transmitting end transducer transmits ultrasonic transmitting signals with different frequencies; acquiring ultrasonic receiving signals with different frequencies, which are received by a receiving end transducer; according to the ultrasonic receiving signals with the different frequencies, the working frequency is determined, and the working frequency is the frequency corresponding to the ultrasonic receiving signal with the maximum amplitude; according to the working frequency, filtering parameters of the receiving end transducer are adjusted, so that the receiving end transducer filters interference signals of non-working frequency; and an excitation source with the working frequency is sent to the transmitting end transducer, so that the transmitting end transducer transmits an ultrasonic transmitting signal with the working frequency. According to the method, the environmental adaptability of the ultrasonic transducer is improved.

Description

Technical Field

[0001] The present application relates to flow measurement technology, and in particular to a transducer control method and an ultrasonic system. Background Art

[0002] An ultrasonic transducer is a device that can convert electromagnetic energy and mechanical energy (sound energy) into each other, thereby transmitting or receiving ultrasonic signals. It is a commonly used equipment in ultrasonic detection technology and is widely used in medicine, industry, materials science and other fields.

[0003] Currently, most ultrasonic transducers use fixed frequencies to send / receive ultrasonic signals. However, they are difficult to adapt to different frequency requirements in different working environments and have the problem of weak environmental adaptability. Summary of the invention

[0004] The present application provides a transducer control method and an ultrasonic system, which are used to improve the environmental adaptability of an ultrasonic transducer.

[0005] On the one hand, the present application provides a transducer control method, applied to a transducer pair, the method comprising:

[0006] Sending excitation sources of different frequencies to the transmitting end transducer so that the transmitting end transducer transmits ultrasonic transmission signals of different frequencies;

[0007] Acquire ultrasonic receiving signals of different frequencies received by the receiving end transducer; determine the operating frequency according to the ultrasonic receiving signals of different frequencies, wherein the operating frequency is the frequency corresponding to the ultrasonic receiving signal with the largest amplitude;

[0008] According to the operating frequency, adjusting the filter parameters of the receiving end transducer so that the receiving end transducer filters out interference signals of non-operating frequencies;

[0009] An excitation source of the operating frequency is sent to the transmitting end transducer, so that the transmitting end transducer transmits an ultrasonic transmitting signal of the operating frequency.

[0010] Optionally, adjusting the filtering parameters of the receiving end transducer according to the operating frequency includes:

[0011] According to the operating frequency, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filter circuit corresponding to the receiving end transducer are adjusted, and the filter parameters include the resistance value and the capacitance value.

[0012] Optionally, adjusting the filtering parameters of the receiving end transducer according to the operating frequency includes:

[0013] According to the correspondence between the preset frequency and the filtering parameter, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filtering circuit corresponding to the receiving end transducer are adjusted to the resistance value and the capacitance value corresponding to the operating frequency.

[0014] Optionally, sending excitation sources of different frequencies to the transmitting end transducer includes:

[0015] Acquire an ultrasonic receiving signal of a first frequency received by the receiving end transducer, and detect a signal-to-noise ratio of the ultrasonic receiving signal of the first frequency;

[0016] If the signal-to-noise ratio does not meet the preset requirement, sending an excitation source of different frequencies to the transmitting end transducer;

[0017] If the signal-to-noise ratio meets the preset requirement, an excitation source of the first frequency is sent to the transmitting-end transducer, so that the transmitting-end transducer transmits an ultrasonic transmitting signal of the first frequency.

[0018] On the other hand, the present application provides an ultrasound system, including: a control circuit, a detection circuit, a filter circuit, and a transducer pair;

[0019] The control circuit is connected to the transducer pair and is used to send excitation sources of different frequencies to the transmitting end transducer in the transducer pair;

[0020] The transmitting end transducer is used to transmit ultrasonic transmission signals of different frequencies under the action of the excitation sources of different frequencies;

[0021] The receiving end transducer in the transducer pair is used to convert ultrasonic receiving signals of different frequencies into electrical signals of different frequencies;

[0022] The detection circuit is connected to the transducer pair and the control circuit, and is used to detect the amplitudes of the ultrasonic receiving signals of different frequencies according to the electrical signals of different frequencies, and send the amplitudes of the ultrasonic receiving signals of different frequencies to the control circuit;

[0023] The control circuit is further used to determine the operating frequency according to the amplitudes of the ultrasonic receiving signals of different frequencies, wherein the operating frequency is the frequency corresponding to the ultrasonic receiving signal with the largest amplitude; adjust the filtering parameters of the filtering circuit according to the operating frequency; and send an excitation source of the operating frequency to the transmitting end transducer;

[0024] The transmitting end transducer is also used to transmit an ultrasonic transmitting signal of the working frequency under the action of the excitation source of the working frequency;

[0025] The filtering circuit is connected to the receiving end transducer and is used to filter out interference signals of non-working frequencies in the electrical signal based on the adjusted filtering parameters.

[0026] Optionally, the control circuit includes: a single chip microcomputer, an excitation circuit and an acquisition circuit;

[0027] The single chip microcomputer is connected to the input end of the excitation circuit and the output end of the detection circuit, and is used to send a variable frequency signal or an operating frequency signal to the excitation circuit; and determine the operating frequency according to the amplitude of the ultrasonic receiving signal of different frequencies;

[0028] The output end of the excitation circuit is connected to the transducer pair, and is used to send the excitation source of different frequencies to the transmitting end transducer according to the frequency conversion signal; or send the excitation source of the working frequency to the transmitting end transducer according to the working frequency signal;

[0029] The input end of the acquisition circuit is connected to the transducer pair, and the output end of the acquisition circuit is connected to the input end of the detection circuit, so as to acquire the electrical signal converted by the receiving end transducer.

[0030] Optionally, the filtering circuit includes at least one variable resistor and at least one capacitor;

[0031] The single chip microcomputer is connected to the filter circuit and is also used to adjust the resistance of at least one variable resistor and the capacitance of at least one variable capacitor in the filter circuit according to the operating frequency.

[0032] Optionally, the filtering circuit includes: a low-pass filtering circuit, a high-pass filtering circuit and a gain control circuit;

[0033] The input end of the low-pass filter circuit is connected to the output end of the acquisition circuit, the input end of the high-pass filter circuit is connected to the output end of the low-pass filter circuit, and the output end of the high-pass filter circuit is connected to the input end of the gain control circuit; or, the input end of the high-pass filter circuit is connected to the output end of the acquisition circuit, the input end of the low-pass filter circuit is connected to the output end of the high-pass filter circuit, and the output end of the low-pass filter circuit is connected to the input end of the gain control circuit; the output end of the gain control circuit is connected to the input end of the detection circuit;

[0034] The low-pass filter circuit is used to filter out interference signals in the electrical signal that are higher than the operating frequency;

[0035] The high-pass filter circuit is used to filter out interference signals in the electrical signal that are lower than the operating frequency;

[0036] The gain control circuit is used to control the amplitude of the electric signal after filtering to keep it stable.

[0037] Optionally, the low-pass filter circuit includes: a first operational amplifier, a first variable resistor, a second variable resistor, a first variable capacitor, a second variable capacitor and a first resistor;

[0038] One end of the first variable resistor is connected to the output end of the acquisition circuit or the output end of the high-pass filter circuit, and the other end of the first variable resistor is connected to the non-inverting input end of the first operational amplifier; one end of the first variable capacitor is connected to the non-inverting input end of the first operational amplifier, and the other end of the first variable capacitor receives a first voltage;

[0039] One end of the first resistor receives the first voltage, and the other end of the first resistor is connected to the inverting input end of the first operational amplifier;

[0040] One end of the second variable resistor and one end of the second variable capacitor are connected to the inverting input terminal of the first operational amplifier, and the other end of the second variable resistor and the other end of the second variable capacitor are connected to the output terminal of the first operational amplifier;

[0041] The output end of the first operational amplifier is connected to the input end of the high-pass filter circuit or the input end of the gain control circuit.

[0042] Optionally, the high-pass filter circuit includes: a second operational amplifier, a third variable resistor, a fourth variable resistor, a third variable capacitor, a fourth variable capacitor, a second resistor and a third resistor;

[0043] One end of the third variable capacitor is connected to the output end of the acquisition circuit or the output end of the low-pass filter circuit, the other end of the third variable capacitor is connected to one end of the third variable resistor and one end of the fourth variable capacitor, and the other end of the third variable resistor is connected to the output end of the second operational amplifier;

[0044] The other end of the fourth variable capacitor is connected to one end of the fourth variable resistor and the non-inverting input end of the second operational amplifier, and the other end of the fourth variable resistor receives a second voltage;

[0045] One end of the second resistor receives the second voltage, and the other end of the second resistor is connected to the inverting input end of the second operational amplifier;

[0046] One end of the third resistor is connected to the inverting input end of the second operational amplifier, and the other end of the third resistor is connected to the output end of the second operational amplifier; the output end of the second operational amplifier is connected to the input end of the low-pass filter circuit or the input end of the gain control circuit.

[0047] Optionally, the gain control circuit includes: a third operational amplifier, a fifth variable resistor, a sixth variable resistor, a fifth variable capacitor and a fourth resistor;

[0048] One end of the fifth variable resistor is connected to the output end of the low-pass filter circuit or the output end of the high-pass filter circuit, and the other end of the fifth variable resistor is connected to one end of the fifth variable capacitor and the non-inverting input end of the third operational amplifier;

[0049] One end of the fourth resistor receives the third voltage, and the other end of the fourth resistor is connected to the inverting input end of the third operational amplifier;

[0050] One end of the sixth variable resistor is connected to the inverting input end of the third operational amplifier, the other end of the sixth variable resistor is connected to the output end of the third operational amplifier, and the output end of the third operational amplifier is connected to the detection circuit.

[0051] Optionally, the control circuit is specifically used for:

[0052] According to the correspondence between the preset frequency and the filtering parameters, the resistance value of at least one variable resistor and the capacitance value of at least one variable capacitor in the filtering circuit corresponding to the receiving end transducer are adjusted to the resistance value and the capacitance value corresponding to the operating frequency.

[0053] Optionally, the excitation circuit includes: a first amplifying circuit, a second amplifying circuit and a transmitting channel;

[0054] The first amplifying circuit receives the frequency conversion signal or the operating frequency signal, and is used to perform a first amplification process on the frequency conversion signal or the operating frequency signal;

[0055] The input end of the second amplifier circuit is connected to the output end of the first amplifier circuit, and is used to perform a second amplification process on the frequency conversion signal or the operating frequency signal after the first amplification process to obtain the excitation source of the different frequency or the excitation source of the operating frequency;

[0056] The input end of the transmitting channel is connected to the output end of the second amplifying circuit, and the output end of the transmitting channel is connected to the transmitting end transducer; the transmitting channel is used to send the excitation source of different frequencies or the excitation source of the working frequency to the transmitting end transducer.

[0057] Optionally, the first amplifying circuit includes: an AND gate;

[0058] The first input terminal and the second input terminal of the AND gate receive the frequency conversion signal or the operating frequency signal.

[0059] Optionally, the second amplifying circuit includes: a power amplifying chip, a first energy storage capacitor, a second energy storage capacitor, a first pull-down resistor, a second pull-down resistor and a first current limiting resistor; the power amplifying chip includes a power pin, an input pin and an output pin;

[0060] The input pin is connected to the output end of the second amplifier circuit, the output pin is connected to one end of the first current limiting resistor, the other end of the first current limiting resistor is connected to the input end of the transmitting channel, and the power pin receives a first power supply;

[0061] One end of the first energy storage capacitor and one end of the second energy storage capacitor are connected to the power pin, and the other end of the first energy storage capacitor and the other end of the second energy storage capacitor are grounded;

[0062] One end of the first pull-down resistor is connected to the input pin, and one end of the second pull-down resistor is connected to the output pin; the other end of the first pull-down resistor and the other end of the second pull-down resistor are grounded.

[0063] Optionally, the output end of the transmitting channel is connected to a transmitting end transducer in at least one transducer pair; the control end of the transmitting channel is connected to the single chip microcomputer, and the transmitting channel is further used for:

[0064] Under the control of the single chip microcomputer, the connection between the output end of the second amplifying circuit and the target transmitting end transducer is turned on, so as to send the excitation source of the different frequency or the excitation source of the working frequency to the target transmitting end transducer.

[0065] Optionally, the acquisition circuit includes: a receiving channel and a third amplification circuit;

[0066] The input end of the receiving channel is connected to the receiving end transducer, the output end of the receiving channel is connected to the input end of the third amplifying circuit, and the receiving channel is used to receive the electrical signal converted by the receiving end transducer;

[0067] The input end of the third amplifying circuit is connected to the output end of the receiving channel, and is used to perform a third amplifying process on the electrical signal.

[0068] Optionally, the input end of the receiving channel is connected to a receiving end transducer in at least one transducer pair; the control end of the receiving channel is connected to the single-chip microcomputer, and the receiving channel is further used for:

[0069] Under the control of the single chip microcomputer, the connection between the target receiving end transducer and the input end of the third amplifying circuit is turned on, so as to receive the electrical signal converted by the target receiving end transducer.

[0070] Optionally, the third amplifying circuit includes: a fourth operational amplifier, a first bypass capacitor, a first capacitor, a fifth resistor, a first coupling capacitor, a first filter capacitor and a second coupling capacitor;

[0071] The power input terminal of the fourth operational amplifier receives the second power supply, one end of the first bypass capacitor is connected to the power input terminal of the fourth operational amplifier, and the other end of the first bypass capacitor is grounded;

[0072] One end of the first capacitor and one end of the fifth resistor are connected to the inverting input terminal of the fourth operational amplifier, and the other end of the first capacitor and the other end of the fifth resistor are connected to the output terminal of the fourth operational amplifier;

[0073] One end of the first coupling capacitor is connected to the output end of the receiving channel, the other end of the first coupling capacitor is connected to one end of the first filter capacitor and the inverting input end of the fourth operational amplifier, the other end of the first filter capacitor is connected to the non-inverting input end of the fourth operational amplifier, and the non-inverting input end of the fourth operational amplifier receives a fourth voltage;

[0074] An output end of the fourth operational amplifier is connected to one end of the second coupling capacitor, and the other end of the second coupling capacitor is connected to the detection circuit.

[0075] Optionally, the detection circuit includes: an amplitude detection circuit and a time detection circuit;

[0076] The amplitude detection circuit is connected to the acquisition circuit and the single chip microcomputer, and is used to detect the amplitude of the ultrasonic receiving signal and send the amplitude of the ultrasonic receiving signal to the single chip microcomputer;

[0077] The time detection circuit is connected to the acquisition circuit and the single chip microcomputer, and is used to detect and obtain the signal-to-noise ratio of the ultrasonic receiving signal, and send the signal-to-noise ratio of the ultrasonic receiving signal to the single chip microcomputer.

[0078] Optionally, the single chip microcomputer is also used for:

[0079] Acquire a signal-to-noise ratio of an ultrasonic receiving signal of a first frequency;

[0080] If the signal-to-noise ratio does not meet the preset requirement, sending a frequency conversion signal to the excitation circuit;

[0081] If the signal-to-noise ratio meets the preset requirement, sending a first frequency signal to the excitation circuit;

[0082] The excitation circuit is further configured to send an excitation source of the first frequency to the transmitting end transducer according to the first frequency signal.

[0083] In the transducer control method and ultrasonic system provided by the present application, by sending excitation sources of different frequencies, the transmitting end transducer is controlled to transmit ultrasonic transmitting signals of different frequencies, and among the ultrasonic receiving signals of different frequencies received by the receiving end transducer, the frequency of the ultrasonic receiving signal with the largest amplitude is used as the working frequency, and the filtering parameters of the receiving end transducer are adjusted according to the working frequency, so as to improve the quality of the ultrasonic receiving signal. On the one hand, the optimal working frequency can be used in different working environments, effectively improving the flexibility and environmental adaptability of the ultrasonic transducer, and reducing the process consistency requirements of the transducer, so that each transducer works at the optimal frequency state. On the other hand, adaptive filtering of the ultrasonic receiving signal can be realized to improve the filtering effect of the ultrasonic receiving signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0085] Figure 1 A schematic diagram of a flow chart of a transducer control method provided in an embodiment of the present application is exemplarily shown in FIG.

[0086] Figure 2 The schematic diagram of the working process of the ultrasonic flow meter provided in the embodiment of the present application is exemplarily shown in FIG.

[0087] Figure 3 The schematic diagram of the structure of the ultrasound system provided in the embodiment of the present application is exemplarily shown in FIG.

[0088] Figure 4 Schematic diagram of the frequency conversion signal provided by the embodiment of the present application is exemplarily shown in FIG.

[0089] Figure 5 A schematic diagram of a scenario for determining an operating frequency provided in an embodiment of the present application is exemplarily shown in FIG.

[0090] Figure 6 The schematic diagram of the ultrasonic flow measurement scenario provided by the embodiment of the present application is exemplarily shown in FIG.

[0091] Figure 7 exemplarily shows a structural schematic diagram of a low-pass filter circuit provided in an embodiment of the present application;

[0092] Figure 8 exemplarily shows a structural schematic diagram of a high-pass filter circuit provided in an embodiment of the present application;

[0093] Fig. 9 exemplarily shows a schematic diagram of the structure of the gain control circuit provided in an embodiment of the present application;

[0094] Fig.10 The structural diagram of the excitation circuit provided in the embodiment of the present application is exemplarily shown in FIG.

[0095] Fig.11 exemplarily shows a structural schematic diagram of a first amplifier circuit provided in an embodiment of the present application;

[0096] Fig.12 exemplarily shows a structural schematic diagram of a second amplifier circuit provided in an embodiment of the present application;

[0097] Fig.13 The structural diagram of the transmission channel provided in the embodiment of the present application is exemplarily shown in FIG.

[0098] Fig.14 The structural diagram of the acquisition circuit provided in the embodiment of the present application is exemplarily shown in FIG.

[0099] Fig.15 The structural diagram of the receiving channel provided by the embodiment of the present application is exemplarily shown in FIG.

[0100] Fig.16 exemplarily shows a structural schematic diagram of a third amplifier circuit provided in an embodiment of the present application;

[0101] Fig.17 The structure diagram of the amplitude detection circuit provided in the embodiment of the present application is exemplarily shown in FIG.

[0102] Fig.18 The schematic diagram of the ultrasonic flow measurement scenario provided in the embodiment of the present application is exemplarily shown in FIG.

[0103] The following are the descriptions of the reference numerals:

[0104] 10-Ultrasound system;

[0105] 11- control circuit;

[0106] 111- single chip microcomputer;

[0107] 112-excitation circuit;

[0108] 1121-first amplifier circuit;

[0109] 1122-second amplifier circuit;

[0110] 1123-transmitting channel;

[0111] 113-collection circuit;

[0112] 1131-receiving channel;

[0113] 1132-third amplifier circuit;

[0114] 114-filter frequency control circuit;

[0115] 12- detection circuit;

[0116] 121-amplitude detection circuit;

[0117] 122-time detection circuit;

[0118] 13- transducer pair;

[0119] 131-transmitter transducer;

[0120] 132-receiving end transducer;

[0121] 14- filter circuit;

[0122] 141- low pass filter circuit;

[0123] 142- high pass filter circuit;

[0124] 143-gain control circuit;

[0125] C147-second bypass capacitor;

[0126] C150-second filter capacitor;

[0127] C17-first energy storage capacitor;

[0128] C18-second energy storage capacitor;

[0129] C21-first capacitor;

[0130] C25- first bypass capacitor;

[0131] C27-first coupling capacitor;

[0132] C28-first filter capacitor;

[0133] C29-second coupling capacitor;

[0134] C91-first variable capacitor;

[0135] C92 - second variable capacitor;

[0136] C93 - the third variable capacitor;

[0137] C94 - fourth variable capacitor;

[0138] C95 - fifth variable capacitor;

[0139] R151 - second variable resistor;

[0140] R152-first variable resistor;

[0141] R16-fourth variable resistor;

[0142] R18-third variable resistor;

[0143] R2-the third resistor;

[0144] R3-sixth variable resistor;

[0145] R4-first current limiting resistor;

[0146] R45-the third current limiting resistor;

[0147] R5 - first pull-down resistor;

[0148] R51-second current limiting resistor;

[0149] R52-the fourth current limiting resistor;

[0150] R55 - pull-up resistor;

[0151] R6-the fourth resistor;

[0152] R7-fifth resistor;

[0153] R8-second resistor;

[0154] R9-fifth variable resistor;

[0155] U12A - fourth operational amplifier;

[0156] U2A - Second operational amplifier;

[0157] U2B - the third operational amplifier;

[0158] U4A - first operational amplifier;

[0159] U14-conversion chip;

[0160] U8-power amplifier chip;

[0161] U9A - AND gate.

[0162] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0163] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0164] The module in this application refers to a functional module or a logical module. It can be in software form, and its functions are realized by executing program code by a processor; it can also be in hardware form. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0165] An ultrasonic transducer is a device that can convert electromagnetic energy and mechanical energy (sound energy) into each other, thereby transmitting or receiving ultrasonic signals. It is a commonly used equipment in ultrasonic detection technology and is widely used in medicine, industry, materials science and other fields.

[0166] Currently, most ultrasonic transducers use fixed frequencies to send / receive ultrasonic signals. However, they are difficult to adapt to different frequency requirements in different working environments and have the problem of weak environmental adaptability.

[0167] Taking ultrasonic flowmeter as an example, ultrasonic flowmeter uses the characteristics of ultrasonic wave propagation in fluid, and calculates the flow rate of fluid by measuring the time difference or phase difference of ultrasonic wave propagation in fluid, including ultrasonic transducer. Under different working environments, the working frequency requirements of ultrasonic flowmeter are also different. For example, in the application of urban gas, the composition and quality of natural gas in different places are also different. The high concentration of methane environment will cause the high-frequency ultrasonic signal to attenuate sharply. At this time, low-frequency ultrasonic wave with smaller attenuation is required to make the receiving end transducer work normally; when the ultrasonic flowmeter is installed near the pressure regulator, the low-frequency noise generated by the pressure regulator will make the low-frequency ultrasonic wave greatly affected by the pressure regulation noise. At this time, high-frequency ultrasonic wave is required to make the receiving end transducer work normally; in addition, due to the individual differences of ultrasonic transducers and the different ambient temperature and pressure used, the optimal working frequency will also change accordingly. Therefore, the fixed frequency ultrasonic flowmeter has the defect of weak environmental adaptability.

[0168] The technical solution of the present application is illustrated below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0169] Figure 1 The flowchart of the transducer control method provided in the embodiment of the present application is shown in FIG. The execution subject of the method may be an ultrasonic system. The method is applied to a transducer pair. Figure 1 As shown, the method may include:

[0170] S101, sending excitation sources of different frequencies to a transmitting end transducer, so that the transmitting end transducer transmits ultrasonic transmission signals of different frequencies.

[0171] In a specific implementation, excitation sources of different frequencies may be sequentially sent to the transmitting end transducer, so that the transmitting end transducer respectively transmits ultrasonic transmission signals of different frequencies, wherein the frequency of the ultrasonic transmission signal emitted by the transmitting end transducer is the same as the frequency of the excitation source.

[0172] Exemplarily, each frequency, the total number of frequencies, and the excitation source sending time corresponding to each frequency are configurable.

[0173] In practical applications, the excitation sources of different frequencies may be excitation sources of different frequency ranges.

[0174] S102, obtaining ultrasonic receiving signals of different frequencies received by a receiving end transducer; determining an operating frequency according to the ultrasonic receiving signals of different frequencies, where the operating frequency is a frequency corresponding to the ultrasonic receiving signal with the largest amplitude.

[0175] In a specific implementation, after the transducer transmits ultrasonic transmission signals of different frequencies respectively, the receiving end transducer receives ultrasonic reception signals of different frequencies respectively. Among them, the frequency of the ultrasonic reception signal is the same as the frequency of the corresponding ultrasonic transmission signal. Since the accuracy of measuring the ultrasonic reception signal is certain, the larger the amplitude of the ultrasonic reception signal, the more accurate the measurement result will be. Therefore, the ultrasonic reception signals of different frequencies can be obtained, and the frequency corresponding to the ultrasonic reception signal with the largest amplitude is taken as the optimal working frequency.

[0176] Each ultrasonic transducer may be used as a transmitting end transducer or a receiving end transducer; or each ultrasonic transducer may be fixedly used as a transmitting end transducer or a receiving end transducer, which is not limited here.

[0177] S103, adjusting the filter parameters of the receiving end transducer according to the operating frequency, so that the receiving end transducer filters out interference signals of non-operating frequencies.

[0178] In a specific implementation, after receiving the ultrasonic receiving signal, the filter circuit corresponding to the receiving end transducer will filter the ultrasonic receiving signal to remove noise interference and avoid affecting the measurement results. Among them, the filtering requirements corresponding to ultrasonic signals of different frequencies are different, so the filtering parameters of the filter circuit corresponding to the receiving end transducer can be adjusted according to the current working frequency, which is referred to as adjusting the filtering parameters of the receiving end transducer, so that the filter circuit only retains the signal of the working frequency during the filtering process, and filters out the interference signal of the non-working frequency, thereby effectively improving the signal-to-noise ratio of the ultrasonic receiving signal.

[0179] S104, sending an excitation source of the operating frequency to the transmitting end transducer, so that the transmitting end transducer transmits an ultrasonic transmitting signal of the operating frequency.

[0180] In a specific implementation, an excitation source of the operating frequency is sent to the transmitting-end transducer so that the transmitting-end transducer transmits an ultrasonic transmission signal of the operating frequency, and the receiving-end transducer receives the ultrasonic transmission signal of the operating frequency, thereby enabling detection to be achieved using the ultrasonic signal of the optimal operating frequency. The optimal operating frequency can be used in different working environments, which can effectively improve the flexibility and environmental adaptability of the ultrasonic transducer.

[0181] Furthermore, the transducer is an electronic component, and there will be deviations between different transducers when leaving the factory. A pair of transducers need to be selected and matched for use, and high process consistency requirements are required. The embodiment of the present application can flexibly adjust the operating frequency of the transducer according to the amplitude of the signal received by the transducer, so that each transducer can operate at the optimal frequency state.

[0182] In practical applications, this method can be used to control one or more pairs of ultrasonic transducers. The operating frequencies of the multiple pairs of ultrasonic transducers can be the same or different, which is not limited here.

[0183] In the embodiment of the present application, by sending excitation sources of different frequencies, the transmitting end transducer is controlled to transmit ultrasonic transmitting signals of different frequencies, and among the ultrasonic receiving signals of different frequencies received by the receiving end transducer, the frequency of the ultrasonic receiving signal with the largest amplitude is used as the operating frequency, and the filtering parameters of the receiving end transducer are adjusted according to the operating frequency, thereby improving the quality of the ultrasonic receiving signal. On the one hand, the optimal operating frequency can be used in different working environments, effectively improving the flexibility and environmental adaptability of the ultrasonic transducer, and reducing the process consistency requirements of the transducer, so that each transducer works at the optimal frequency state. On the other hand, adaptive filtering of the ultrasonic receiving signal can be realized to improve the filtering effect of the ultrasonic receiving signal.

[0184] Based on the above embodiment, in a possible implementation manner, adjusting the filter parameters of the receiving end transducer according to the operating frequency includes:

[0185] According to the operating frequency, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filter circuit corresponding to the receiving end transducer are adjusted, and the filter parameters include the resistance value and the capacitance value.

[0186] In a specific implementation, the resistance and capacitance in the filter circuit of the receiving end transducer can be set to be variable, and the filter parameters can include the capacitance value and the resistance value. By adjusting the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filter circuit, the filter frequency of the filter circuit can be changed, so that the filter circuit can filter out interference signals of non-working frequencies.

[0187] Exemplarily, adjusting the filter parameters of the receiving end transducer according to the operating frequency includes:

[0188] According to the correspondence between the preset frequency and the filtering parameter, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filtering circuit corresponding to the receiving end transducer are adjusted to the resistance value and the capacitance value corresponding to the operating frequency.

[0189] In a specific implementation, the correspondence between multiple frequencies and filtering parameters can be pre-set, so that after determining the operating frequency, the filtering parameters corresponding to the current operating frequency can be quickly and conveniently obtained, and the filtering parameters of the filtering circuit of the receiving end transducer can be adjusted to the filtering parameters corresponding to the operating frequency.

[0190] In the embodiment of the present application, the filtering parameters of the receiving end transducer are adjusted according to the operating frequency, which can effectively enhance the filtering effect and improve the signal-to-noise ratio of the ultrasonic receiving signal, thereby improving the accuracy and reliability of ultrasonic detection.

[0191] In a possible implementation, sending excitation sources of different frequencies to the transmitting end transducer includes:

[0192] Acquire an ultrasonic receiving signal of a first frequency received by a receiving end transducer, and detect a signal-to-noise ratio of the ultrasonic receiving signal of the first frequency, and if the signal-to-noise ratio does not meet a preset requirement, send an excitation source of a different frequency to the transmitting end transducer;

[0193] If the signal-to-noise ratio meets the preset requirement, an excitation source of the first frequency is sent to the transmitting end transducer, so that the transmitting end transducer transmits an ultrasonic transmission signal of the first frequency.

[0194] In a specific implementation, due to the influence of environmental factors and other factors, the optimal operating frequency of the transducer may change, and different operating frequencies need to be used at different times. Therefore, the signal-to-noise ratio of the ultrasonic receiving signal of the first frequency received by the current receiving end transducer can be detected, and it can be determined whether the signal-to-noise ratio meets the preset requirements. If it does not meet the preset requirements, it indicates that the frequency of the ultrasonic transmission signal needs to be adjusted, and excitation sources of different frequencies need to be sent to the transmitting end transducer to determine the current optimal operating frequency, so that the transducer is always in the best working state, effectively improving the flexibility and reliability of the transducer. If it meets the preset requirements, the first frequency can continue to be used as the frequency of the ultrasonic transmission signal, effectively ensuring the working performance of the transducer.

[0195] The following uses an ultrasonic flowmeter application scenario as an example to further illustrate the transducer control method provided in the embodiment of the present application. Figure 2 This is a schematic diagram of the operation flow of the ultrasonic flow meter provided in the embodiment of the present application. Figure 2 As shown, after the ultrasonic flowmeter starts working, it first sends excitation sources of different frequencies to the transmitting end transducer to make the transmitting end transducer emit ultrasonic transmission signals of different frequencies; the operating frequency is determined according to the ultrasonic receiving signals of different frequencies received by the receiving end transducer; the filtering parameters of the receiving end transducer are adjusted according to the operating frequency; it is judged whether the signal-to-noise ratio of the ultrasonic receiving signal of the operating frequency meets the preset requirements, if not, the excitation sources of different frequencies are re-sent to the transmitting end transducer, so as to adjust the operating frequency; if the signal-to-noise ratio of the ultrasonic receiving signal of the operating frequency meets the preset requirements, the excitation source of the operating frequency is sent to the transmitting end transducer, and the propagation time of the ultrasonic signal is calculated, so as to calculate the flow rate of the fluid according to the propagation time; after each measurement, it can be re-judged whether the signal-to-noise ratio of the current ultrasonic receiving signal meets the preset requirements, so as to determine whether to adjust the operating frequency until the measurement is completed.

[0196] Figure 3 This is a schematic diagram of the structure of the ultrasound system provided in the embodiment of the present application. Figure 3 As shown, the ultrasound system 10 may include: a control circuit 11, a detection circuit 12, a transducer pair 13 and a filter circuit 14;

[0197] The control circuit 11 is connected to the transducer pair 13 and is used to send excitation sources of different frequencies to the transmitting end transducer 131 in the transducer pair 13;

[0198] The transmitting end transducer 131 is used to transmit ultrasonic transmission signals of different frequencies under the action of excitation sources of different frequencies;

[0199] The receiving end transducer 132 in the transducer pair 13 is used to convert ultrasonic receiving signals of different frequencies into electrical signals of different frequencies;

[0200] The detection circuit 12 is connected to the transducer pair 13 and the control circuit 11, and is used to detect the amplitudes of ultrasonic receiving signals of different frequencies according to the electrical signals of different frequencies, and send the amplitudes of ultrasonic receiving signals of different frequencies to the control circuit 11;

[0201] The control circuit 11 is further used to determine the operating frequency according to the amplitudes of ultrasonic receiving signals of different frequencies, the operating frequency being the frequency corresponding to the ultrasonic receiving signal with the largest amplitude; adjust the filtering parameters of the filtering circuit according to the operating frequency; and send an excitation source of the operating frequency to the transmitting end transducer 131;

[0202] The transmitting end transducer 131 is also used to transmit an ultrasonic transmitting signal of the working frequency under the action of an excitation source of the working frequency;

[0203] The filter circuit 14 is connected to the receiving end transducer 132 and is used to filter out interference signals of non-operating frequencies in the electrical signal based on the adjusted filter parameters.

[0204] In a specific implementation, the control circuit 11 can sequentially send excitation sources of different frequencies to the transmitting end transducer 131, and the transmitting end transducer 131, under the excitation of the excitation sources of different frequencies, respectively transmits ultrasonic transmission signals of different frequencies. Among them, the frequency of the ultrasonic transmission signal emitted by the transmitting end transducer 131 is the same as the frequency of the excitation source. In practical applications, the excitation sources of different frequencies can be excitation sources of different frequency ranges. The receiving end transducer 132 receives ultrasonic receiving signals of different frequencies. Among them, the frequency of the ultrasonic receiving signal is the same as the frequency of the corresponding ultrasonic transmitting signal. The detection circuit 12 detects the frequency of the ultrasonic receiving signal, obtains the amplitude of the ultrasonic receiving signal of different frequencies, and sends the amplitude of the ultrasonic receiving signal of different frequencies to the control circuit 11. Since the accuracy of measuring the ultrasonic receiving signal is certain, the larger the amplitude of the ultrasonic receiving signal, the more accurate the measurement result will be. Therefore, the control circuit 11 uses the frequency corresponding to the ultrasonic receiving signal with the largest amplitude as the optimal operating frequency. The control circuit 11 sends an excitation source of the working frequency to the transmitting end transducer 131 ; under the excitation of the excitation source of the working frequency, the transmitting end transducer 131 transmits an ultrasonic transmission signal of the working frequency.

[0205] The two ultrasonic transducers in the transducer pair 13 can be used as the transmitting end transducer 131 or the receiving end transducer 132 in turn; or, the two ultrasonic transducers can be fixed as the transmitting end transducer or the receiving end transducer, which is not limited here.

[0206] In an embodiment of the present application, by sending excitation sources of different frequencies, the transmitting end transducer is controlled to transmit ultrasonic transmitting signals of different frequencies, and among the ultrasonic receiving signals of different frequencies received by the receiving end transducer, the frequency of the ultrasonic receiving signal with the largest amplitude is used as the operating frequency, thereby improving the quality of the ultrasonic receiving signal. On the one hand, the optimal operating frequency can be used in different working environments, effectively improving the flexibility and environmental adaptability of the ultrasonic transducer; on the other hand, the process consistency requirements of the transducer pair can be reduced, so that each transducer can work at the optimal frequency state.

[0207] In a possible implementation, the control circuit 11 includes: a single chip computer 111, an excitation circuit 112 and a collection circuit 113;

[0208] The single chip computer 111 is connected to the excitation circuit 112 and the detection circuit 12, and is used to send a variable frequency signal or an operating frequency signal to the excitation circuit 112; and determine the operating frequency according to the amplitude of the ultrasonic receiving signal of different frequencies;

[0209] The excitation circuit 112 is connected to the transducer pair 13, and is used to send an excitation source of different frequencies to the transmitting end transducer 131 according to the frequency conversion signal; or, according to the working frequency signal, send an excitation source of the working frequency to the transmitting end transducer 131;

[0210] The acquisition circuit 113 is connected to the transducer pair 13 and is used to sample the ultrasonic receiving signal.

[0211] In a specific implementation, the excitation circuit 112 is used to send an excitation source to the transmitting end transducer 131, so that the transmitting end transducer 131 transmits an ultrasonic transmission signal under the excitation of the excitation source; the acquisition circuit 113 is used to sample the ultrasonic reception signal received by the receiving end transducer 132. The single-chip microcomputer 111 can control the excitation circuit 112 to output an excitation source of a corresponding frequency by sending different frequency signals to the excitation circuit 112. Among them, the single-chip microcomputer 111 can send a variable frequency signal to the excitation circuit 112 according to a preset internal algorithm, and the excitation circuit 112 sends an excitation source of different frequencies to the transmitting end transducer 131; when the single-chip microcomputer 111 sends a fixed frequency signal to the excitation circuit 112, the excitation circuit 112 sends the fixed frequency excitation source to the transmitting end transducer 131.

[0212] Figure 4 Schematic diagram of the frequency conversion signal provided in the embodiment of the present application. Figure 4 As shown, the frequency conversion signal includes multiple frequency signals, and the frequencies or frequency ranges of the multiple frequency signals are different. The frequency range of the frequency conversion signal, the total number of frequency signals, and the sending time of each frequency signal can be set according to actual needs.

[0213] Figure 5 A schematic diagram of a scenario for determining an operating frequency provided in an embodiment of the present application. Figure 5 As shown, the single chip microcomputer 111 can send N frequency conversion signals to control the transmitting end transducer 131 to transmit N ultrasonic transmitting signals of different frequencies, and determine the frequency f of the ultrasonic receiving signal with the largest amplitude as the optimal operating frequency according to the amplitudes of the N ultrasonic receiving signals of different frequencies received by the receiving end transducer 132.

[0214] In a possible implementation, the filter circuit 14 includes at least one variable resistor and at least one capacitor;

[0215] The single chip computer 111 is connected to the filter circuit 14 and is also used to adjust the resistance of at least one variable resistor and the capacitance of at least one variable capacitor in the filter circuit according to the operating frequency.

[0216] In a specific implementation, assuming that the frequency of the ultrasonic receiving signal is f1, the filter circuit 14 only retains the signal with a frequency of f1 in the ultrasonic receiving signal, and filters out interference signals of other frequencies, thereby obtaining a filtered ultrasonic receiving signal, removing noise interference, and avoiding affecting the measurement result. The filtering requirements corresponding to ultrasonic signals of different frequencies are different, so the single-chip microcomputer 111 can adjust the filtering parameters of the filter circuit 14 according to the current working frequency, so that the filter circuit 14 only retains the signal of the working frequency during the filtering process, and filters out interference signals of non-working frequencies, thereby effectively improving the signal-to-noise ratio of the ultrasonic receiving signal. The filter circuit 14 can include multiple variable resistors and multiple variable capacitors; the single-chip microcomputer 111 can adjust the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filter circuit 14 to adjust the filtering parameters of the filter circuit 14.

[0217] Exemplarily, the control circuit 11 may further include: a filter frequency control circuit 114. The single chip microcomputer 111 may send a frequency control signal to the filter frequency control circuit 114. The filter frequency control circuit 114 controls the filter parameters of the filter circuit 14 according to the frequency control signal.

[0218] Exemplarily, the control circuit 11 is specifically used to: adjust the resistance value of at least one variable resistor and the capacitance value of at least one variable capacitor in the filter circuit 14 corresponding to the receiving end transducer 132 to the resistance value and capacitance value corresponding to the operating frequency according to the corresponding relationship between the preset frequency and the filter parameter.

[0219] Figure 6 This is a schematic diagram of the structure of the filter circuit provided in the embodiment of the present application. Figure 6 As shown, in a possible implementation, the filter circuit 14 includes: a low-pass filter circuit 141, a high-pass filter circuit 142 and a gain control circuit 143;

[0220] The input end of the low-pass filter circuit 141 is connected to the output end of the acquisition circuit 113, the input end of the high-pass filter circuit 142 is connected to the output end of the low-pass filter circuit 141, and the output end of the high-pass filter circuit 142 is connected to the input end of the gain control circuit 143; or, the input end of the high-pass filter circuit 142 is connected to the output end of the acquisition circuit 113, the input end of the low-pass filter circuit 141 is connected to the output end of the high-pass filter circuit 142, and the output end of the low-pass filter circuit 141 is connected to the input end of the gain control circuit 143; the output end of the gain control circuit 143 is connected to the input end of the detection circuit;

[0221] A low-pass filter circuit 141 is used to filter out interference signals higher than the working frequency in the electrical signal;

[0222] A high-pass filter circuit 142 is used to filter out interference signals in the electrical signal that are lower than the working frequency;

[0223] The gain control circuit 143 is used to control the amplitude of the filtered electrical signal to remain stable.

[0224] In a specific implementation, the interference signal in the electrical signal that is higher than the operating frequency can be filtered out by the low-pass filter circuit 141, and the interference signal in the electrical signal that is lower than the operating frequency can be filtered out by the high-pass filter circuit 142, thereby filtering out the interference signal of the non-operating frequency in the electrical signal. The low-pass filter circuit 141 can be set in the front stage or the rear stage of the high-pass filter circuit 142, and is not limited here. Since the amplitude of the electrical signal varies greatly, the gain control circuit 143 is connected to the output end of the low-pass filter circuit 141 / high-pass filter circuit 142, and the amplitude of the filtered electrical signals of different amplitudes can be limited to a limited range, so that the detection circuit 12 can accurately detect the frequency of the electrical signal.

[0225] Figure 7 This is a schematic diagram of the structure of the low-pass filter circuit provided in the embodiment of the present application. Figure 7 As shown, exemplarily, the low-pass filter circuit 141 includes: a first operational amplifier U4A, a first variable resistor R152, a second variable resistor R151, a first variable capacitor C91, a second variable capacitor C92 and a first resistor R11;

[0226] One end of the first variable resistor R152 is connected to the output end of the acquisition circuit 113 or the output end of the high-pass filter circuit 142, and the other end of the first variable resistor R152 is connected to the non-inverting input end of the first operational amplifier U4A; one end of the first variable capacitor C91 is connected to the non-inverting input end of the first operational amplifier U4A, and the other end of the first variable capacitor C91 receives the first voltage;

[0227] One end of the first resistor R11 receives the first voltage, and the other end of the first resistor R11 is connected to the inverting input end of the first operational amplifier U4A;

[0228] One end of the second variable resistor R151 and one end of the second variable capacitor C92 are connected to the inverting input terminal of the first operational amplifier U4A, and the other end of the second variable resistor R151 and the other end of the second variable capacitor C92 are connected to the output terminal of the first operational amplifier U4A;

[0229] The output terminal of the first operational amplifier U4A is connected to the input terminal of the high-pass filter circuit 142 or the input terminal of the gain control circuit 143 .

[0230] In a specific implementation, the first operational amplifier U4A, the first variable resistor R152, the second variable resistor R151, the first variable capacitor C91, the second variable capacitor C92 and the first resistor R11 form a second-order low-pass filter, wherein the resistance of the first resistor R11 is fixed, the resistance of the first variable resistor R152 and the second variable resistor R151 are adjusted by the single-chip microcomputer 111, and the capacitance of the first variable capacitor C91 and the second variable capacitor C92 are adjusted by the single-chip microcomputer 111. By adjusting the first variable resistor R152, the second variable resistor R151 and the first variable capacitor C91 and the second variable capacitor C92, the filtering frequency of the low-pass filter circuit 141 can be changed. Among them, the first voltage can be set according to actual needs, for example, it can be 1.65V.

[0231] Figure 8 This is a schematic diagram of the structure of the high-pass filter circuit provided in the embodiment of the present application. Figure 8 As shown, exemplarily, the high-pass filter circuit 142 includes: a second operational amplifier U2A, a third variable resistor R18, a fourth variable resistor R16, a third variable capacitor C93, a fourth variable capacitor C94, a second resistor R8 and a third resistor R2;

[0232] One end of the third variable capacitor C93 is connected to the output end of the acquisition circuit 113 or the output end of the low-pass filter circuit 141, the other end of the third variable capacitor C93 is connected to one end of the third variable resistor R18 and one end of the fourth variable capacitor C94, and the other end of the third variable resistor R18 is connected to the output end of the second operational amplifier U2A;

[0233] The other end of the fourth variable capacitor C94 is connected to one end of the fourth variable resistor R16 and the non-inverting input end of the second operational amplifier U2A, and the other end of the fourth variable resistor R16 receives the second voltage;

[0234] One end of the second resistor R8 receives the second voltage, and the other end of the second resistor R8 is connected to the inverting input end of the second operational amplifier U2A;

[0235] One end of the third resistor R2 is connected to the inverting input end of the second operational amplifier U2A, and the other end of the third resistor R2 is connected to the output end of the second operational amplifier U2A; the output end of the second operational amplifier U2A is connected to the input end of the low-pass filter circuit 141 or the input end of the gain control circuit 143.

[0236] In a specific implementation, the second operational amplifier U2A, the third variable resistor R18, the fourth variable resistor R16, the third variable capacitor C93, the fourth variable capacitor C94, the second resistor R8 and the third resistor R2 form a second-order high-pass filter. The resistance values ​​of the second resistor R8 and the third resistor R2 are fixed, the resistance values ​​of the third variable resistor R18 and the fourth variable resistor R16 are adjusted by the single-chip microcomputer 111, and the capacitance values ​​of the third variable capacitor C93 and the fourth variable capacitor C94 are adjusted by the single-chip microcomputer 111. By adjusting the third variable resistor R18, the fourth variable resistor R16 and the third variable capacitor C93, the fourth variable capacitor C94, the filtering frequency of the high-pass filter circuit 142 can be changed. The second voltage can be set according to actual needs, for example, it can be 1.65V.

[0237] Fig. 9 This is a schematic diagram of the structure of the gain control circuit provided in the embodiment of the present application. Fig. 9 As shown, illustratively, the gain control circuit 143 includes: a third operational amplifier U2B, a fifth variable resistor R9, a sixth variable resistor R3, a fifth variable capacitor C95 and a fourth resistor R6;

[0238] One end of the fifth variable resistor R9 is connected to the output end of the low-pass filter circuit 141 or the output end of the high-pass filter circuit 142, and the other end of the fifth variable resistor R9 is connected to one end of the fifth variable capacitor C95 and the non-inverting input end of the third operational amplifier U2B;

[0239] One end of the fourth resistor R6 receives the third voltage, and the other end of the fourth resistor R6 is connected to the inverting input end of the third operational amplifier U2B;

[0240] One end of the sixth variable resistor R3 is connected to the inverting input end of the third operational amplifier U2B, the other end of the sixth variable resistor R3 is connected to the output end of the third operational amplifier U2B, and the output end of the third operational amplifier U2B is connected to the detection circuit 12.

[0241] In a specific implementation, the third operational amplifier U2B, the fifth variable resistor R9, the sixth variable resistor R3, the fifth variable capacitor C95 and the fourth resistor R6 form a gain control circuit. The fourth resistor R6 has a fixed resistance, the fifth variable resistor R9 and the sixth variable resistor R3 have resistances adjusted by the single-chip microcomputer 111, and the capacitance of the fifth variable capacitor C95 is adjusted by the single-chip microcomputer 111. By adjusting the fifth variable resistor R9, the sixth variable resistor R3 and the fifth variable capacitor C95, the amplitude of the electrical signal output by the third operational amplifier U2B can be changed. The third voltage can be set according to actual needs, for example, it can be 1.65V.

[0242] Fig.10 This is a schematic diagram of the structure of the excitation circuit provided in the embodiment of the present application. Fig.10 As shown, in a possible implementation, the excitation circuit 112 includes: a first amplifying circuit 1121, a second amplifying circuit 1122 and a transmitting channel 1123;

[0243] The first amplifier circuit 1121 receives the frequency conversion signal or the operating frequency signal, and is used to perform a first amplification process on the frequency conversion signal or the operating frequency signal;

[0244] The input end of the second amplifier circuit 1122 is connected to the output end of the first amplifier circuit 1121, and is used to perform a second amplification process on the frequency conversion signal or the working frequency signal after the first amplification process to obtain an excitation source of a different frequency or an excitation source of a working frequency;

[0245] The input end of the transmitting channel 1123 is connected to the output end of the second amplifying circuit 1122 , and the output end of the transmitting channel 1123 is connected to the transmitting end transducer 131 ; the transmitting channel 1123 is used to send excitation sources of different frequencies or an excitation source of the working frequency to the transmitting end transducer 131 .

[0246] In a specific implementation, the frequency conversion signal or the working frequency signal is subjected to secondary amplification processing by the first amplifying circuit 1121 and the second amplifying circuit 1122, and the excitation source is output to the transmitting end transducer 131 through the transmitting channel 1123, which can increase the amplitude of the excitation source, thereby increasing the intensity of the ultrasonic transmission signal emitted by the transmitting end transducer 131, which is beneficial to improving the signal-to-noise ratio of the ultrasonic receiving signal.

[0247] Fig.11 This is a schematic diagram of the structure of the first amplifier circuit provided in the embodiment of the present application. Fig.11 As shown, the first amplifier circuit 1121 includes: an AND gate U9A;

[0248] The first input terminal and the second input terminal of the AND gate U9A receive the frequency conversion signal or the operating frequency signal.

[0249] In a specific implementation, the frequency conversion signal or the operating frequency signal sent by the single chip microcomputer 111 can be conveniently amplified in the first stage through the AND gate U9A.

[0250] Fig.12 Schematic diagram of the structure of the second amplifier circuit provided in the embodiment of the present application. Fig.12 As shown, the second amplifier circuit 1122 includes: a power amplifier chip U8, a first energy storage capacitor C17, a second energy storage capacitor C18, a first pull-down resistor R5, a second pull-down resistor R6 and a first current limiting resistor R4; the power amplifier chip U8 includes a power pin VCC, an input pin IN and an output pin OUT;

[0251] The input pin IN of the power amplifier chip U8 is connected to the output end of the second amplifier circuit 1122, the output pin OUT of the power amplifier chip U8 is connected to one end of the first current limiting resistor R4, the other end of the first current limiting resistor R4 is connected to the input end of the transmitting channel 1123, and the power pin VCC of the power amplifier chip U8 receives the first power supply VPP1;

[0252] One end of the first energy storage capacitor C17 and one end of the second energy storage capacitor C18 are connected to the power pin VCC of the power amplifier chip U8, and the other end of the first energy storage capacitor C17 and the other end of the second energy storage capacitor C18 are grounded;

[0253] One end of the first pull-down resistor R5 is connected to the input pin IN of the power amplifier chip U8, and one end of the second pull-down resistor R6 is connected to the output pin OUT of the power amplifier chip U8; the other end of the first pull-down resistor R5 and the other end of the second pull-down resistor R6 are grounded.

[0254] In a specific implementation, the power amplifier chip U8 can amplify the amplitude of the electrical signal output from the output pin OUT of the power amplifier chip U8 to several times the amplitude of the electrical signal input to the input pin IN of the power amplifier chip U8. The power pin VCC of the power amplifier chip U8 receives the first power supply VPP1, and the first energy storage capacitor C17 and the second energy storage capacitor C18 connected to ground are arranged at the first power supply VPP1, which can ensure the stability of the supply voltage of the first power supply VPP1 when the load of the power amplifier chip U8 changes rapidly, which is conducive to improving the stability of the system. The first pull-down resistor R5 and the second pull-down resistor R6 are used to provide a stable low level for the input pin IN and the output pin OUT of the power amplifier chip U8 when there is no signal input to the input pin IN of the power amplifier chip U8. The first current limiting resistor R4 can limit the current output from the output pin OUT of the power amplifier chip U8, thereby protecting the transmission channel 1123.

[0255] Fig.13 This is a schematic diagram of the structure of the transmission channel provided in the embodiment of the present application. Fig.13 As shown, the output end of the transmitting channel 1123 is connected to the transmitting end transducer 131 in at least one transducer pair; the control end of the transmitting channel 1123 is connected to the single chip microcomputer, and the transmitting channel 1123 is also used for:

[0256] Under the control of the single chip microcomputer 111, the connection between the output end of the second amplifying circuit 1122 and the target transmitting end transducer is turned on, so as to send an excitation source of a different frequency or an excitation source of an operating frequency to the target transmitting end transducer.

[0257] Taking an 8-channel transmitting channel as an example, the 8 output terminals S11, S12, S13, S14, S15, S16, S17, and S18 of the transmitting channel 1123 are connected to the 8 transmitting end transducers 131, the enabling terminal EN of the transmitting channel 1123 receives the transmitting enable signal sent by the single-chip microcomputer 111, and the A0 terminal, A1 terminal, and A2 terminal of the transmitting channel 1123 receive the binary signal sent by the single-chip microcomputer 111. When the transmitting enable signal is enabled, the transmitting channel 1123 conducts the connection between the output terminal corresponding to the three-bit binary signal received by the A0 terminal, the A1 terminal, and the A2 terminal and the input terminal COM of the transmitting channel 1123. For example, assuming that the A0 terminal, the A1 terminal, and the A2 terminal receive 1, 1, and 1 respectively, the corresponding output terminal is S18. In practical applications, the transmitting channel 1123 can be provided with A0~An-1 terminals to implement 2 n output channels.

[0258] Fig.14 This is a schematic diagram of the structure of the acquisition circuit provided in the embodiment of the present application. Fig.14 As shown, in a possible implementation, the acquisition circuit 113 includes: a receiving channel 1131 and a third amplification circuit 1132;

[0259] The input end of the receiving channel 1131 is connected to the receiving end transducer 132, the output end of the receiving channel 1131 is connected to the input end of the third amplifying circuit 1132, and the receiving channel 1131 is used to receive the electrical signal converted by the receiving end transducer 132;

[0260] An input end of the third amplifying circuit 1132 is connected to an output end of the receiving channel 1131 for performing a third amplifying process on the electrical signal.

[0261] In a specific implementation, since the ultrasonic signal will weaken during the propagation process, the electrical signal converted by the receiving end transducer 132 is received through the receiving channel 1131, and the electrical signal is amplified through the input end of the third amplifier circuit 1132, so that the ultrasonic receiving signal can be better detected.

[0262] Fig.15 This is a schematic diagram of the structure of the receiving channel provided in the embodiment of the present application. Fig.15 As shown, illustratively, the input end of the receiving channel 1131 is connected to the receiving end transducer 132 in at least one transducer pair; the control end of the receiving channel 1131 is connected to the single-chip microcomputer, and the receiving channel 1131 is also used for:

[0263] Under the control of the single chip microcomputer, the connection between the target receiving end transducer 132 and the input end of the third amplifying circuit 1132 is turned on, so as to receive the electrical signal converted by the target receiving end transducer 132 .

[0264] Taking an 8-channel receiving channel as an example, the 8 input terminals S1, S2, S3, S4, S5, S6, S7, and S8 of the receiving channel 1131 are connected to the 8 receiving transducers 132, the enable terminal EN of the receiving channel 1131 receives the receiving enable signal sent by the single-chip microcomputer 111, and the A0 terminal, A1 terminal, and A2 terminal of the receiving channel 1131 receive the binary signal sent by the single-chip microcomputer 111. When the receiving enable signal is enabled, the receiving channel 1131 conducts the connection between the input terminals corresponding to the three-bit binary signals received by the A0 terminal, A1 terminal, and A2 terminal and the output terminal COM of the receiving channel 1131. For example, assuming that the A0 terminal, A1 terminal, and A2 terminal receive 1, 1, and 1 respectively, the corresponding input terminal is S8. In actual applications, the receiving channel 1131 can set the A0~An-1 terminals to implement 2 n input channels.

[0265] Fig.16 This is a schematic diagram of the structure of the third amplifier circuit provided in the embodiment of the present application. Fig.16 As shown, illustratively, the third amplifier circuit 1132 includes: a fourth operational amplifier U12A, a first bypass capacitor C25, a first capacitor C21, a fifth resistor R7, a first coupling capacitor C27, a first filter capacitor C28 and a second coupling capacitor C29;

[0266] The power input terminal of the fourth operational amplifier U12A receives the second power supply VDDA, one end of the first bypass capacitor C25 is connected to the power input terminal of the fourth operational amplifier U12A, and the other end of the first bypass capacitor C25 is grounded;

[0267] One end of the first capacitor C21 and one end of the fifth resistor R7 are connected to the inverting input terminal of the fourth operational amplifier U12A, and the other end of the first capacitor C21 and the other end of the fifth resistor R7 are connected to the output terminal of the fourth operational amplifier U12A;

[0268] One end of the first coupling capacitor C27 is connected to the output end of the receiving channel 1131, the other end of the first coupling capacitor C27 is connected to one end of the first filter capacitor C28 and the inverting input end of the fourth operational amplifier U12A, the other end of the first filter capacitor C28 is connected to the non-inverting input end of the fourth operational amplifier U12A, and the non-inverting input end of the fourth operational amplifier U12A receives the fourth voltage;

[0269] The output end of the fourth operational amplifier U12A is connected to one end of the second coupling capacitor C29 , and the other end of the second coupling capacitor C29 is connected to the detection circuit 12 .

[0270] In a specific implementation, the fourth operational amplifier U12A, the first capacitor C21, and the fifth resistor R7 form a signal amplification circuit, which amplifies the electrical signal several times and then inputs it into the back-end detection circuit 12. The first filter capacitor C28 is used to filter the received electrical signal to remove noise interference. The first coupling capacitor C27 and the second coupling capacitor C29 can pass AC, block DC, pass high frequency, and block low frequency. They can decouple unwanted DC signals and couple the required AC signals from the front-stage circuit to the back-stage circuit with approximately no attenuation. The power input terminal of the fourth operational amplifier U12A receives the power supply VDDA, and the power input terminal of the fourth operational amplifier U12A is provided with a grounded first bypass capacitor C25, which can provide a low-impedance path to filter out high-frequency noise. Among them, the fourth voltage can be set according to actual needs, for example, it can be 1.5V.

[0271] like Figure 3 As shown, in a possible implementation, the detection circuit 12 includes: an amplitude detection circuit 121 and a time detection circuit 122;

[0272] The amplitude detection circuit 121 is connected to the acquisition circuit 113 and the single-chip microcomputer 111, and is used to detect the amplitude of the ultrasonic receiving signal and send the amplitude of the ultrasonic receiving signal to the single-chip microcomputer 111;

[0273] The time detection circuit 122 is connected to the acquisition circuit 113 and the single chip microcomputer 111 , and is used to detect the signal-to-noise ratio of the ultrasonic receiving signal, and send the signal-to-noise ratio of the ultrasonic receiving signal to the single chip microcomputer 111 .

[0274] In a specific implementation, the amplitude detection circuit 121 and the time detection circuit 122 can respectively detect the amplitude and the signal-to-noise ratio of the ultrasonic reception signal according to the electrical signal corresponding to the ultrasonic reception signal, and send the detection results to the single chip computer 111.

[0275] Fig.17 This is a schematic diagram of the structure of the amplitude detection circuit provided in the embodiment of the present application. Fig.17As shown, exemplarily, the amplitude detection circuit 121 may include a conversion chip U14, a second current limiting resistor R51, a second bypass capacitor C147, a second filter capacitor C150, a pull-up resistor R55, a third current limiting resistor R45, and a fourth current limiting resistor R52. Among them, one end of the second current limiting resistor R51 is connected to the filter circuit 14, and the other end of the second current limiting resistor R51 is connected to the input terminal VIN of the conversion chip U14, one end of the pull-up resistor R55, and one end of the second filter capacitor C150, and the other end of the pull-up resistor R55 and the other end of the second filter capacitor C150 are grounded. The ground terminal GND of the conversion chip U14 is grounded, and the power supply terminal VDD of the conversion chip U14 receives the power supply VDD2. The power supply terminal VDD of the conversion chip U14 and the ground terminal GND of the conversion chip U14 are connected in series with a second bypass capacitor C147. The DATA terminal, CS terminal and SCLK terminal of the conversion chip U14 are connected to the single-chip computer 111. The conversion chip U14 is used to convert the analog electrical signal received by the input terminal VIN of the conversion chip U14 into a digital signal DSP_DATA, and output it through the DATA terminal of the conversion chip U14. The CS terminal and SCLK terminal of the conversion chip U14 respectively output the chip selection signal DSP_CS and the clock signal DSP_CLK to the single-chip microcomputer 111. The single-chip microcomputer 111 analyzes and processes the ultrasonic receiving signal according to the digital signal DSP_DATA, the chip selection signal DSP_CS and the clock signal DSP_CLK.

[0276] Exemplarily, the time detection circuit 122 may include an amplifying circuit. The time detection circuit 122 is also connected to the excitation circuit 112. The microcontroller 111 may send a frequency signal to the time detection circuit 122. After the time detection circuit 122 preliminarily amplifies the frequency signal, it sends the amplified frequency signal to the excitation circuit 112.

[0277] In a possible implementation, the single chip computer 111 is further used for:

[0278] Acquire the signal-to-noise ratio of the ultrasonic receiving signal of the first frequency, and if the signal-to-noise ratio does not meet the preset requirement, send a frequency conversion signal to the excitation circuit 112; if the signal-to-noise ratio meets the preset requirement, send the first frequency signal to the excitation circuit 112;

[0279] The excitation circuit 112 is further configured to send an excitation source of the first frequency to the transmitting end transducer 131 according to the first frequency signal.

[0280] In a specific implementation, due to the influence of environmental factors, the optimal operating frequency of the transducer may change, and different operating frequencies need to be used at different times. Therefore, when the current ultrasonic signal frequency is the first frequency, the single-chip microcomputer 111 can determine whether the signal-to-noise ratio of the ultrasonic receiving signal of the first frequency meets the preset requirements, and when it does not meet the preset requirements, it sends a frequency conversion signal to the excitation circuit 112, thereby reselecting the optimal operating frequency, so that the transducer is always in the best working state, effectively improving the flexibility and reliability of the transducer. When the signal-to-noise ratio of the ultrasonic receiving signal of the first frequency meets the preset requirements, the single-chip microcomputer 111 continues to send the first frequency signal to the excitation circuit 112, thereby continuing to use the first frequency signal as the current operating frequency.

[0281] In a possible implementation, the time detection circuit 122 is further configured to:

[0282] The propagation time of the ultrasonic receiving signal is detected and sent to the single chip microcomputer 111 .

[0283] In a specific implementation, the time detection circuit 122 detects the propagation time of the ultrasonic receiving signal and sends the propagation time to the single chip microcomputer 111. The single chip microcomputer 111 can perform relevant calculations and processing for ultrasonic detection according to the propagation time of the ultrasonic receiving signal. Taking ultrasonic distance measurement as an example, the single chip microcomputer 111 can calculate the distance of surrounding objects according to the propagation time of the ultrasonic receiving signal; taking ultrasonic flow measurement as an example, the single chip microcomputer 111 can calculate the flow rate of the fluid according to the propagation time of the ultrasonic receiving signal.

[0284] Fig.18 This is a schematic diagram of the ultrasonic flow measurement scenario provided in the embodiment of the present application. Fig.18 As shown, after determining the optimal operating frequency f, the single chip microcomputer 111 can control the transducer to transmit or receive ultrasonic signals at the operating frequency f through an operating frequency signal with a frequency of f, and calculate the flow rate of the fluid according to the propagation time of the ultrasonic signal.

[0285] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0286] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A transducer control method, characterized in that: Applied to a transducer pair, the method comprises: Sending excitation sources of different frequencies to the transmitting end transducer so that the transmitting end transducer transmits ultrasonic transmission signals of different frequencies; Acquire ultrasonic receiving signals of different frequencies received by the receiving end transducer; determine the operating frequency according to the ultrasonic receiving signals of different frequencies, wherein the operating frequency is the frequency corresponding to the ultrasonic receiving signal with the largest amplitude; According to the operating frequency, adjusting the filter parameters of the receiving end transducer so that the receiving end transducer filters out interference signals of non-operating frequencies; An excitation source of the operating frequency is sent to the transmitting end transducer, so that the transmitting end transducer transmits an ultrasonic transmitting signal of the operating frequency.

2. The method according to claim 1, characterized in that The step of adjusting the filter parameters of the receiving end transducer according to the operating frequency includes: According to the operating frequency, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filter circuit corresponding to the receiving end transducer are adjusted, and the filter parameters include the resistance value and the capacitance value.

3. The method according to claim 2, characterized in that The step of adjusting the filter parameters of the receiving end transducer according to the operating frequency includes: According to the correspondence between the preset frequency and the filtering parameter, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the filtering circuit corresponding to the receiving end transducer are adjusted to the resistance value and the capacitance value corresponding to the operating frequency.

4. The method according to any one of claims 1 to 3, characterized in that: The sending of excitation sources of different frequencies to the transmitting end transducer comprises: Acquire an ultrasonic receiving signal of a first frequency received by the receiving end transducer, and detect a signal-to-noise ratio of the ultrasonic receiving signal of the first frequency; If the signal-to-noise ratio does not meet the preset requirement, sending an excitation source of different frequencies to the transmitting end transducer; If the signal-to-noise ratio meets the preset requirement, an excitation source of the first frequency is sent to the transmitting-end transducer, so that the transmitting-end transducer transmits an ultrasonic transmitting signal of the first frequency.

5. An ultrasound system, characterized in that: include: A control circuit, a detection circuit, a filter circuit and a transducer pair; The control circuit is connected to the transducer pair and is used to send excitation sources of different frequencies to the transmitting end transducer in the transducer pair; The transmitting end transducer is used to transmit ultrasonic transmission signals of different frequencies under the action of the excitation sources of different frequencies; The receiving end transducer in the transducer pair is used to convert ultrasonic receiving signals of different frequencies into electrical signals of different frequencies; The detection circuit is connected to the transducer pair and the control circuit, and is used to detect the amplitudes of the ultrasonic receiving signals of different frequencies according to the electrical signals of different frequencies, and send the amplitudes of the ultrasonic receiving signals of different frequencies to the control circuit; The control circuit is further used to determine the operating frequency according to the amplitudes of the ultrasonic receiving signals of different frequencies, wherein the operating frequency is the frequency corresponding to the ultrasonic receiving signal with the largest amplitude; and adjust the filtering parameters of the filtering circuit according to the operating frequency; and, an excitation source that sends an operating frequency to the transmitting end transducer; The transmitting end transducer is also used to transmit an ultrasonic transmitting signal of the working frequency under the action of the excitation source of the working frequency; The filtering circuit is connected to the receiving end transducer and is used to filter out interference signals of non-working frequencies in the electrical signal based on the adjusted filtering parameters.

6. The system according to claim 5, characterized in that The control circuit includes: a single chip microcomputer, an excitation circuit and a collection circuit; The single chip microcomputer is connected to the input end of the excitation circuit and the output end of the detection circuit, and is used to send a variable frequency signal or an operating frequency signal to the excitation circuit; and determine the operating frequency according to the amplitude of the ultrasonic receiving signal of different frequencies; The output end of the excitation circuit is connected to the transducer pair, and is used to send the excitation source of different frequencies to the transmitting end transducer according to the frequency conversion signal; or send the excitation source of the working frequency to the transmitting end transducer according to the working frequency signal; The input end of the acquisition circuit is connected to the transducer pair, and the output end of the acquisition circuit is connected to the input end of the detection circuit, so as to acquire the electrical signal converted by the receiving end transducer.

7. The system according to claim 6, characterized in that The filter circuit includes at least one variable resistor and at least one capacitor; The single chip microcomputer is connected to the filter circuit and is also used to adjust the resistance of at least one variable resistor and the capacitance of at least one variable capacitor in the filter circuit according to the operating frequency.

8. The system according to claim 7, characterized in that The filter circuit includes: a low-pass filter circuit, a high-pass filter circuit and a gain control circuit; The input end of the low-pass filter circuit is connected to the output end of the acquisition circuit, the input end of the high-pass filter circuit is connected to the output end of the low-pass filter circuit, and the output end of the high-pass filter circuit is connected to the input end of the gain control circuit; or, the input end of the high-pass filter circuit is connected to the output end of the acquisition circuit, the input end of the low-pass filter circuit is connected to the output end of the high-pass filter circuit, and the output end of the low-pass filter circuit is connected to the input end of the gain control circuit; the output end of the gain control circuit is connected to the input end of the detection circuit; The low-pass filter circuit is used to filter out interference signals in the electrical signal that are higher than the operating frequency; The high-pass filter circuit is used to filter out interference signals in the electrical signal that are lower than the operating frequency; The gain control circuit is used to control the amplitude of the electric signal after filtering to keep it stable.

9. The system according to claim 8, characterized in that The low-pass filter circuit comprises: a first operational amplifier, a first variable resistor, a second variable resistor, a first variable capacitor, a second variable capacitor and a first resistor; One end of the first variable resistor is connected to the output end of the acquisition circuit or the output end of the high-pass filter circuit, and the other end of the first variable resistor is connected to the non-inverting input end of the first operational amplifier; one end of the first variable capacitor is connected to the non-inverting input end of the first operational amplifier, and the other end of the first variable capacitor receives a first voltage; One end of the first resistor receives the first voltage, and the other end of the first resistor is connected to the inverting input end of the first operational amplifier; One end of the second variable resistor and one end of the second variable capacitor are connected to the inverting input terminal of the first operational amplifier, and the other end of the second variable resistor and the other end of the second variable capacitor are connected to the output terminal of the first operational amplifier; The output end of the first operational amplifier is connected to the input end of the high-pass filter circuit or the input end of the gain control circuit.

10. The system according to claim 8, characterized in that The high-pass filter circuit includes: a second operational amplifier, a third variable resistor, a fourth variable resistor, a third variable capacitor, a fourth variable capacitor, a second resistor and a third resistor; One end of the third variable capacitor is connected to the output end of the acquisition circuit or the output end of the low-pass filter circuit, the other end of the third variable capacitor is connected to one end of the third variable resistor and one end of the fourth variable capacitor, and the other end of the third variable resistor is connected to the output end of the second operational amplifier; The other end of the fourth variable capacitor is connected to one end of the fourth variable resistor and the non-inverting input end of the second operational amplifier, and the other end of the fourth variable resistor receives a second voltage; One end of the second resistor receives the second voltage, and the other end of the second resistor is connected to the inverting input end of the second operational amplifier; One end of the third resistor is connected to the inverting input end of the second operational amplifier, and the other end of the third resistor is connected to the output end of the second operational amplifier; the output end of the second operational amplifier is connected to the input end of the low-pass filter circuit or the input end of the gain control circuit.

11. The system according to claim 8, characterized in that The gain control circuit includes: a third operational amplifier, a fifth variable resistor, a sixth variable resistor, a fifth variable capacitor and a fourth resistor; One end of the fifth variable resistor is connected to the output end of the low-pass filter circuit or the output end of the high-pass filter circuit, and the other end of the fifth variable resistor is connected to one end of the fifth variable capacitor and the non-inverting input end of the third operational amplifier; One end of the fourth resistor receives the third voltage, and the other end of the fourth resistor is connected to the inverting input end of the third operational amplifier; One end of the sixth variable resistor is connected to the inverting input end of the third operational amplifier, the other end of the sixth variable resistor is connected to the output end of the third operational amplifier, and the output end of the third operational amplifier is connected to the detection circuit.

12. The system according to claim 7, characterized in that The control circuit is specifically used for: According to the correspondence between the preset frequency and the filtering parameters, the resistance value of at least one variable resistor and the capacitance value of at least one variable capacitor in the filtering circuit corresponding to the receiving end transducer are adjusted to the resistance value and the capacitance value corresponding to the operating frequency.

13. The system according to claim 6, characterized in that The excitation circuit includes: a first amplifying circuit, a second amplifying circuit and a transmitting channel; The first amplifying circuit receives the frequency conversion signal or the operating frequency signal, and is used to perform a first amplification process on the frequency conversion signal or the operating frequency signal; The input end of the second amplifier circuit is connected to the output end of the first amplifier circuit, and is used to perform a second amplification process on the frequency conversion signal or the operating frequency signal after the first amplification process to obtain the excitation source of the different frequency or the excitation source of the operating frequency; The input end of the transmitting channel is connected to the output end of the second amplifying circuit, and the output end of the transmitting channel is connected to the transmitting end transducer; the transmitting channel is used to send the excitation source of different frequencies or the excitation source of the working frequency to the transmitting end transducer.

14. The system according to claim 7, characterized in that The acquisition circuit includes: a receiving channel and a third amplifying circuit; The input end of the receiving channel is connected to the receiving end transducer, the output end of the receiving channel is connected to the input end of the third amplifying circuit, and the receiving channel is used to receive the electrical signal converted by the receiving end transducer; The input end of the third amplifying circuit is connected to the output end of the receiving channel, and is used to perform a third amplifying process on the electrical signal.

15. The system according to any one of claims 6 to 14, characterized in that: The detection circuit comprises: an amplitude detection circuit and a time detection circuit; The amplitude detection circuit is connected to the acquisition circuit and the single chip microcomputer, and is used to detect the amplitude of the ultrasonic receiving signal and send the amplitude of the ultrasonic receiving signal to the single chip microcomputer; The time detection circuit is connected to the acquisition circuit and the single chip microcomputer, and is used to detect and obtain the signal-to-noise ratio of the ultrasonic receiving signal, and send the signal-to-noise ratio of the ultrasonic receiving signal to the single chip microcomputer.

16. The system according to claim 15, characterized in that The single chip microcomputer is also used for: Acquire a signal-to-noise ratio of an ultrasonic receiving signal of a first frequency; If the signal-to-noise ratio does not meet the preset requirement, sending a frequency conversion signal to the excitation circuit; If the signal-to-noise ratio meets the preset requirement, sending a first frequency signal to the excitation circuit; The excitation circuit is further configured to send an excitation source of the first frequency to the transmitting end transducer according to the first frequency signal.

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