Measuring device, measuring method and equipment for sound wave flying time

Abstract

The invention discloses a sound wave flying time measuring device, method and equipment, and belongs to the field of sound wave measurement. The measuring device for the sound wave flying time comprises a control module, a pulse generation unit, an excitation transducer, a response transducer, a sound wave feature detection unit, a flying time measuring unit and a comparator assembly, the flying time measuring unit, the sound wave characteristic detecting unit and the pulse generating unit are electrically connected with the control module; the pulse generation unit is electrically connected with the excitation transducer, the comparator assembly and the flying time measurement unit, the response transducer is electrically connected with the comparator assembly, and the comparator assembly is electrically connected with the acoustic wave feature detection unit and the flying time measurement unit. The sound wave feature detection unit is electrically connected with the response transducer, the flying time measurement unit and the control module.

Description

Technical Field

[0001] The present application belongs to the field of sound wave measurement, and specifically relates to a device, method and equipment for measuring the flight time of a sound wave. Background Art

[0002] With the development of science and technology, the application of ultrasonic measurement is becoming more and more extensive. Specifically, the ultrasonic wave is transmitted in the measuring tube, and the transmission time is affected by the fluid type and flow rate of the fluid in the measuring tube. Therefore, the flow rate, flow rate and other parameters of the fluid in the measuring tube can be determined by measuring the transmission time of the ultrasonic wave in the measuring tube. Among them, an excitation transducer is set at one end of the measuring tube, and a response transducer is set at the other end. After the excitation transducer is excited, an ultrasonic wave is generated. The ultrasonic wave is transmitted in the measuring tube, and then the ultrasonic wave is transmitted to the response transducer. The time for the ultrasonic wave to be transmitted in the fluid in the measuring tube is regarded as the time interval from the excitation transducer generating the ultrasonic wave to the response transducer receiving the ultrasonic wave. The time for the ultrasonic wave to be transmitted in the fluid in the measuring tube is also called the flight time of the ultrasonic wave. However, in the related art, the method for measuring the flight time of the ultrasonic wave cannot accurately determine the measurement result, especially in the case of noise interference, the measurement result will be inaccurate, resulting in other parameters determined according to the flight time of the ultrasonic wave are also inaccurate. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a device, method and equipment for measuring the ultrasonic flight time, which at least solves the problem that the results of ultrasonic flight time measurement are inaccurate, resulting in inaccurate other parameters determined based on the ultrasonic flight time.

[0004] In a first aspect, an embodiment of the present application provides a device for measuring acoustic wave transit time, the device comprising: a control module, a pulse generating unit, a transducer assembly, an acoustic wave characteristic detecting unit, a transit time measuring unit and a comparator assembly;

[0005] The flight time measurement unit, the acoustic wave characteristic detection unit, and the pulse generating unit are all electrically connected to the control module; the pulse generating unit is electrically connected to the transducer assembly, the comparator assembly, and the flight time measurement unit, respectively, the transducer assembly is electrically connected to the comparator assembly, the comparator assembly is electrically connected to the acoustic wave characteristic detection unit and the flight time measurement unit, and the acoustic wave characteristic detection unit is electrically connected to the transducer assembly, the flight time measurement unit, and the control module, respectively; the transducer assembly is used to generate and transmit an acoustic wave group, and / or receive an acoustic wave group;

[0006] The pulse generating unit is used to generate an initial pulse group, and the initial pulse group can be transmitted to the flight time measuring unit, the comparator component and the transducer component. The flight time measuring unit is used to determine the start time of the acoustic wave flight when receiving the initial pulse group. The transducer component is used to stimulate the transducer component to generate and emit an acoustic wave group when receiving the initial pulse group, and the transducer component is also used to generate a response voltage wave group when receiving the acoustic wave group, and the response voltage wave group can be transmitted to the acoustic wave characteristic detection unit and the comparator component; the acoustic wave characteristic detection unit is used to detect the peak amplitude or waveform intercept of the response voltage wave, and send the detection result to the control module, and the control module determines whether the peak amplitude or waveform intercept of the response voltage wave is attenuated; or, the acoustic wave characteristic detection unit detects the peak amplitude or waveform intercept of the response voltage wave, and determines whether the peak amplitude or waveform intercept of the response voltage wave is attenuated;

[0007] When it is determined that the peak amplitude attenuation or the waveform intercept attenuation of the response voltage wave is attenuated, the flight time measurement unit stops the current wave group measurement and determines the stop time of the sound wave flight. The flight time measurement unit or the control module determines the flight time of the sound wave group according to the start time and stop time of the sound wave flight.

[0008] Optionally, the device for measuring the acoustic wave transit time further comprises a reference voltage generating unit;

[0009] The reference voltage generating unit is electrically connected to the control module and the comparator component respectively, and is used to provide a comparison reference voltage to the comparator component, wherein the comparison reference voltage is a voltage greater than or equal to a zero-crossing voltage value.

[0010] Optionally, the comparator component comprises a first comparator;

[0011] The first comparator is electrically connected to the reference voltage generating unit, the flight time measuring unit, the acoustic wave characteristic detecting unit, the transducer assembly, and the pulse generating unit respectively;

[0012] The response voltage wave group transmitted to the first comparator can be transmitted to the flight time measurement unit. The control module controls the reference voltage generating unit to provide the first comparator with a comparison reference voltage greater than the zero-crossing voltage value, so that the first comparator performs a non-zero comparison on the response voltage wave group. When the peak value of the response voltage wave is higher than the comparison reference voltage, the first comparator outputs a non-zero comparison pulse. After one or more non-zero comparison pulses are output, the control module controls the reference voltage generating unit to provide the first comparator with a comparison reference voltage equal to the zero-crossing voltage value, so that the first comparator performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse until the measurement process ends.

[0013] Optionally, the acoustic wave feature detection unit includes a first peak detector, a first analog-to-digital converter, and a first register, a second register, and a third register;

[0014] The first peak detector is electrically connected to the transducer assembly and the first analog-to-digital converter, respectively, the first register is electrically connected to the second register, the second register is electrically connected to the third register, the first register is electrically connected to the first comparator, and the first analog-to-digital converter is electrically connected to the control module;

[0015] The first peak detector is used to detect the peak amplitude of the response voltage wave in each cycle of the response voltage wave group transmitted from the transducer assembly, and the control module is used to read the peak amplitude of the response voltage wave from the first analog-to-digital converter, and determine whether the peak amplitude of the response voltage wave is attenuated based on the read peak amplitude of the response voltage wave;

[0016] The first register is used to receive a comparison pulse transmitted from the first comparator, and the first register and the second register are used to perform a two-level clock synchronization register delay on the comparison pulse to stabilize the comparator pulse transmitted to the third register. The third register is used to generate a high-level pulse when the received comparator pulse signal changes from a high level to a low level to indicate that the first analog-to-digital converter has completed the conversion, so that the control module can read data from the first analog-to-digital converter.

[0017] Optionally, the acoustic wave feature detection unit includes a second peak detector, a third peak detector, a first hysteresis comparator, a second analog-to-digital converter, a fourth register, a fifth register, a sixth register and a seventh register;

[0018] The second peak detector and the third peak detector are both electrically connected to the transducer assembly, and the second peak detector and the third peak detector are both electrically connected to the first hysteresis comparator and the second analog-to-digital converter; the fourth register is electrically connected to the fifth register, the fifth register is electrically connected to the sixth register, the fourth register is electrically connected to the first comparator, and the second analog-to-digital converter is electrically connected to the control module;

[0019] The second peak detector is used to continuously detect and record the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group transmitted from the transducer assembly, and transmit the maximum value of the peak amplitude of the response voltage wave detected and recorded to the first hysteresis comparator. The third peak detector is used to detect and record the current peak amplitude of the response voltage wave according to the period of the response voltage wave, and transmit the detected and recorded current peak amplitude of the response voltage wave to the first hysteresis comparator. The first hysteresis comparator is used to detect the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector and the current peak amplitude of the response voltage wave transmitted by the third peak detector. The first hysteresis comparator transmits the comparison result to the seventh register, the seventh register is electrically connected to the control module and the flight time measurement unit, and when the peak amplitude of the response voltage wave is attenuated, the seventh register sends a peak amplitude attenuation flag signal to the flight time measurement unit to make the flight time measurement unit stop the current wave group measurement, and the seventh register sends a peak amplitude attenuation interrupt signal to the control module to make the control module read the data measured by the flight time measurement unit from the flight time measurement unit;

[0020] The fourth register is used to receive the comparator pulse signal transmitted from the first comparator, and the fourth register and the fifth register are used to perform a two-level clock synchronization register delay on the comparator pulse signal so that the clock sampling of the comparator pulse signal transmitted to the sixth register is stable. The sixth register is electrically connected to the seventh register. The sixth register is used to generate a high-level pulse when the comparator pulse signal sent by the fifth register changes from a high level to a low level, so as to instruct the seventh register to collect the comparison result output by the first hysteresis comparator from the first hysteresis comparator, and the sixth register is also used to transmit a reset signal timing to the third peak detector.

[0021] Optionally, the comparator component includes a second comparator and a third comparator;

[0022] The second comparator is electrically connected to the flight time measurement unit, the pulse generating unit, the transducer assembly, the acoustic wave characteristic detection unit, and the reference voltage generating unit. The reference voltage generating unit is used to provide the second comparator with a comparison reference voltage equal to the zero-crossing voltage value of the compared response voltage wave group, so that the second comparator performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse. The third comparator is electrically connected to the transducer assembly, the acoustic wave characteristic detection unit, and the reference voltage generating unit, respectively. The reference voltage generating unit is used to provide the third comparator with a comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, so that the third comparator performs a non-zero comparison on the response voltage wave group and outputs a non-zero comparison pulse.

[0023] Optionally, the acoustic wave feature detection unit includes a first peak detector, a first analog-to-digital converter, and a first register, a second register, and a third register;

[0024] The first peak detector is electrically connected to the transducer assembly and the first analog-to-digital converter, respectively, the first register is electrically connected to the second register, the second register is electrically connected to the third register, the first register is electrically connected to the second comparator or the third comparator, and the first analog-to-digital converter is electrically connected to the control module;

[0025] The first peak detector is used to detect the peak amplitude of the response voltage wave in each cycle of the response voltage wave group transmitted from the transducer assembly, and the control module is used to read the peak amplitude of the response voltage wave from the first analog-to-digital converter, and determine whether the peak amplitude of the response voltage wave is attenuated based on the read peak amplitude of the response voltage wave;

[0026] The first register is used to receive a comparison pulse transmitted from the second comparator or the third comparator, and the first register and the second register are used to perform a two-level clock synchronization register delay on the comparison pulse to stabilize the comparator pulse transmitted to the third register. The third register is used to generate a high-level pulse when the received comparator pulse signal changes from a high level to a low level to indicate that the first analog-to-digital converter has completed the conversion, so that the control module can read data from the first analog-to-digital converter.

[0027] Optionally, the acoustic wave feature detection unit includes a second peak detector, a third peak detector, a first hysteresis comparator, a second analog-to-digital converter, a fourth register, a fifth register, a sixth register and a seventh register;

[0028] The second peak detector and the third peak detector are both electrically connected to the transducer assembly, and the second peak detector and the third peak detector are both electrically connected to the first hysteresis comparator and the second analog-to-digital converter; the fourth register is electrically connected to the fifth register, the fifth register is electrically connected to the sixth register, the fourth register is electrically connected to the second comparator or the third comparator, and the second analog-to-digital converter is electrically connected to the control module;

[0029] The second peak detector is used to continuously detect and record the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group transmitted from the transducer assembly, and transmit the maximum value of the peak amplitude of the response voltage wave detected and recorded to the first hysteresis comparator. The third peak detector is used to detect and record the current peak amplitude of the response voltage wave according to the period of the response voltage wave, and transmit the detected and recorded current peak amplitude of the response voltage wave to the first hysteresis comparator. The first hysteresis comparator is used to detect the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector and the current peak amplitude of the response voltage wave transmitted by the third peak detector. The first hysteresis comparator transmits the comparison result to the seventh register, the seventh register is electrically connected to the control module and the flight time measurement unit, and when the peak amplitude of the response voltage wave is attenuated, the seventh register sends a peak amplitude attenuation flag signal to the flight time measurement unit to make the flight time measurement unit stop the current wave group measurement, and the seventh register sends a peak amplitude attenuation interrupt signal to the control module to make the control module read the data measured by the flight time measurement unit from the flight time measurement unit;

[0030] The fourth register is used to receive the comparator pulse signal transmitted from the second comparator or the third comparator, and the fourth register and the fifth register are used to perform a two-level clock synchronization register delay on the comparator pulse signal so that the clock sampling of the comparator pulse signal transmitted to the sixth register is stable. The sixth register is electrically connected to the seventh register. The sixth register is used to generate a high-level pulse when the comparator pulse signal transmitted by the fifth register changes from a high level to a low level, so as to instruct the seventh register to collect the comparison result output by the first hysteresis comparator from the first hysteresis comparator, and the sixth register is also used to transmit a reset signal timing to the third peak detector.

[0031] Optionally, the acoustic wave feature detection unit includes a first waveform intercept detection unit, a sub-comparator, a gate, an eighth register, a second hysteresis comparator, a ninth register, a tenth register, an eleventh register, a twelfth register, a thirteenth register and a first control unit;

[0032] The first waveform intercept detection unit is electrically connected to the control module, the third comparator, the sub-comparator, the gate and the second hysteresis comparator respectively, the first control unit is electrically connected to the control module, the first waveform intercept detection unit, the second hysteresis comparator, the eighth register and the ninth register, the gate is electrically connected to the first waveform intercept detection unit, the sub-comparator and the eighth register respectively, the eighth register is electrically connected to the second hysteresis comparator, the second hysteresis comparator is electrically connected to the ninth register, the first waveform intercept detection unit, the sub-comparator and the gate respectively, the ninth register is electrically connected to the first control unit, the flight time measurement unit, the second hysteresis comparator is electrically connected to the first control unit, the second The hysteresis comparator is used to compare the waveform intercept value of the current response voltage wave transmitted from the first waveform intercept detection unit and the maximum intercept value of the response voltage wave group recorded and maintained by the eighth register, and send the comparison result to the first control unit, the first control unit sends the comparison result to the control module, when the waveform intercept of the response voltage wave group attenuates beyond the attenuation threshold, the ninth register sends a waveform intercept attenuation flag signal to the fly-time measurement unit to make the fly-time measurement unit stop the current wave group measurement, and the ninth register sends a waveform intercept attenuation signal to the first control unit, the first control unit sends a waveform intercept attenuation interrupt signal to the control module, so that the control module reads the data measured by the fly-time measurement unit from the fly-time measurement unit;

[0033] The eleventh register is electrically connected to the second comparator or the third comparator, the eleventh register is electrically connected to the twelfth register, the twelfth register is electrically connected to the thirteenth register, and the thirteenth register is electrically connected to the tenth register;

[0034] The eleventh register is used to receive the comparator pulse signal transmitted by the second comparator or the third comparator, and the eleventh register and the twelfth register are used to perform two-level clock synchronization register delay on the comparator pulse signal so that the clock sampling of the comparator pulse signal transmitted to the thirteenth register is stable. The thirteenth register is electrically connected to the eighth register. The thirteenth register is used to generate a high-level pulse when the comparator pulse signal transmitted by the twelfth register changes from a high level to a low level to instruct the eighth register to update the saved data, otherwise the eighth register saves the data that has been transmitted to the eighth register. The high-level pulse generated by the thirteenth register is delayed by one clock cycle by the tenth register to instruct the ninth register to collect the result of the comparison output of the second hysteresis comparator and transmit the collected result to the first control unit, and the thirteenth register is also used to transmit the reset signal timing to the first waveform intercept detection unit.

[0035] Optionally, the acoustic wave feature detection unit includes a second control unit and a second waveform intercept detection unit;

[0036] The second control unit is electrically connected to the second waveform intercept detection unit, and the second control unit is also electrically connected to the control module and the third comparator respectively;

[0037] The second control unit is used to receive the comparator pulse signal output from the third comparator, and convert the comparator pulse signal into a conversion pulse signal that can be identified and detected by the second waveform intercept detection unit, and send it to the second waveform intercept detection unit. The second waveform intercept detection unit is used to detect the rising edge and the falling edge of the conversion pulse signal, and send the detection values ​​of the detected rising edge and the falling edge to the second control unit. The control module periodically and continuously reads the detection values ​​of the rising edge and the falling edge from the second control unit, and determines the waveform intercept value of each response voltage wave based on the detection values ​​of the rising edge and the falling edge to determine whether the waveform intercept of the response wave group is attenuated.

[0038] Optionally, the device for measuring the acoustic wave transit time further comprises a pulse counting unit;

[0039] The pulse counting unit is electrically connected to the control module and the comparator component respectively. The pulse counting unit is used to count the number of pulses transmitted to the pulse counting unit and transmit the counted number of pulses to the control module.

[0040] Optionally, the flight time measurement unit includes a third control unit, a time measurement unit and a data cache unit;

[0041] The time measurement unit is electrically connected to the third control unit and the data cache unit respectively, the third control unit is electrically connected to the data cache unit, the time measurement unit is used to detect the start time and the stop time, and the data cache unit is used to cache the detected data;

[0042] Wherein, the third control unit is electrically connected to the control module.

[0043] Optionally, the data cache unit includes

[0044] At least two levels of cache register groups, at least two levels of the cache register groups being electrically connected to the third control unit;

[0045] At least two levels of cache register groups include at least a first cache register group and a second cache register group, and the first cache register group and the second cache register group are both electrically connected to the third control unit;

[0046] When the peak amplitude or waveform intercept of the response voltage wave begins to decay, the first buffer register group is used to store the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the last initial pulse in the initial pulse group; the second buffer register group is used to store the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the second last initial pulse in the initial pulse group.

[0047] Optionally, the device for measuring the acoustic wave transit time further comprises:

[0048] The device for measuring the acoustic wave transit time further comprises a first output buffer and a second output buffer, and the transducer assembly comprises a first transducer and a second transducer;

[0049] The first output buffer is electrically connected to the pulse generating unit and the first transducer respectively, and the second output buffer is electrically connected to the pulse generating unit and the second transducer respectively;

[0050] One of the first transducer and the second transducer serves as an excitation transducer, and the other serves as a response transducer. When the first output buffer is configured as an output state and the second output buffer is configured as a cut-off state, the first output buffer provides an excitation voltage and a current for the first transducer, so that the first transducer serves as an excitation transducer and the second transducer serves as a response transducer. The first transducer generates and transmits a sound wave group, and the second transducer receives the sound wave group and generates a response voltage wave group. The response transducer is electrically connected to the comparator component and the sound wave feature detection unit. When the second output buffer is configured as an output state and the first output buffer is configured as a cut-off state, the second output buffer provides an excitation voltage and a current for the second transducer, so that the second transducer serves as an excitation transducer and the first transducer serves as a response transducer. The second transducer generates and transmits a sound wave group, and the first transducer receives the sound wave group and generates a response voltage wave group. The response transducer is electrically connected to the comparator component and the sound wave feature detection unit.

[0051] Optionally, the device for measuring the acoustic wave transit time further comprises a measuring tube;

[0052] The excitation transducer is arranged at the first end of the measuring tube, and the response transducer is arranged at the second end of the measuring tube.

[0053] Optionally, the device for measuring the acoustic wave transit time further comprises a third output buffer, and the transducer assembly comprises a third transducer;

[0054] The third output buffer is electrically connected to the pulse generating unit and the third transducer respectively, and the third transducer is electrically connected to the comparator component and the acoustic wave characteristic detecting unit;

[0055] When the third output buffer is configured in the output state, the third output buffer provides the third transducer with an excitation voltage and a current, and the third transducer generates and transmits a sound wave group; when the third output buffer is configured in the cut-off state, the third output buffer stops providing the third transducer with an excitation voltage and a current, and the third transducer receives the sound wave group and generates a response voltage wave group.

[0056] Optionally, the device for measuring the acoustic wave flight time further comprises an analog gate;

[0057] The analog gate is electrically connected to the pulse generating unit and the transducer component, and the analog gate is electrically connected to the comparator component. The analog gate is switched on so that the initial pulse group emitted by the pulse generating unit is transmitted to the comparator component, or the response voltage wave group generated by the transducer component is transmitted to the comparator component.

[0058] Optionally, the acoustic wave transit time measuring device further comprises a first coupling capacitor and a second coupling capacitor, and the transducer assembly comprises a first transducer and a second transducer;

[0059] The first coupling capacitor is electrically connected to the first transducer, and the second coupling capacitor is electrically connected to the second transducer;

[0060] Wherein, when the first transducer is used as a transducer component, the first coupling capacitor is used to couple the response voltage of the first transducer to the comparator component and / or the acoustic wave characteristic detection unit; when the second transducer is used as a transducer component, the second coupling capacitor is used to couple the response voltage of the second transducer to the comparator component and / or the acoustic wave characteristic detection unit.

[0061] Optionally, the device for measuring the acoustic wave transit time further includes a third coupling capacitor and a third transducer;

[0062] The third coupling capacitor is electrically connected to the third transducer;

[0063] Wherein, when the third transducer is used as a response transducer, the third coupling capacitor is used to couple the response voltage of the third transducer to the comparator component and the acoustic wave characteristic detection unit, or to the comparator component.

[0064] In a second aspect, an embodiment of the present application provides a method for measuring acoustic wave transit time, which is applied to the acoustic wave transit time measuring device described in any one of the first aspects above, and the measuring method includes:

[0065] Determine the starting time of the acoustic wave flight;

[0066] Determining the stop time of the acoustic wave flight;

[0067] The flying time of the ultrasonic wave group is determined according to the starting time and the stopping time.

[0068] Optionally, the stop time includes at least two consecutive flyby stop times;

[0069] Before determining the flight time of the sound wave group according to the start time and the stop time, the method for measuring the sound wave flight time further includes:

[0070] Detect whether the stop time is valid. If the stop time is valid, determine the flight time of the sound wave group according to the start time and the stop time; if the stop time is invalid, redetermine the stop time until the stop time is valid.

[0071] Optionally, detecting whether the stop time is valid includes:

[0072] Subtract two consecutive fly-by stop times to obtain a fly-by stop time difference; compare the fly-by stop time difference with the emission period of the pulse generator to emit pulses, if the difference between the fly-by stop time difference and the emission period is within a preset difference range, then both of the two fly-by stop times are valid; if the difference between the fly-by stop time difference and the emission period is outside the preset difference range, then both of the two fly-by stop times are invalid;

[0073] Or, subtract any two adjacent fly stop times from at least three consecutive fly stop times to obtain at least two fly stop time differences; compare any of the fly stop time differences with the emission period of the pulse emitted by the pulse generator; if the difference between the fly stop time difference and the emission period is within a preset difference range, then the two fly stop times corresponding to the fly stop time difference are both valid; if the difference between the fly stop time difference and the emission period is outside the preset difference range, then the two fly stop times corresponding to the fly stop time difference are both invalid.

[0074] Optionally, the flight time measuring device further comprises a reference voltage generating unit, a first comparator or a third comparator, and a pulse counting unit;

[0075] Before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the method for measuring the acoustic wave flight time further includes:

[0076] Acquire a measured value of the pulse output from the first comparator or the third comparator measured by the pulse counting unit within a preset time period;

[0077] Determining whether the measurement value is within a preset value range;

[0078] If the measurement value is within the preset value range, the non-zero comparison reference voltage of the first comparator or the third comparator is not adjusted;

[0079] If the metered value is not within the preset value range, and the metered value is less than the minimum value of the preset value range, the non-zero comparison reference voltage of the first comparator or the third comparator is reduced until the metered value is within the preset value range; if the metered value is greater than the maximum value of the preset value range, the non-zero comparison reference voltage of the first comparator or the third comparator is increased until the metered value is within the preset value range.

[0080] Optionally, the acoustic wave feature detection unit includes a first hysteresis comparator, the first hysteresis comparator has a first hysteresis comparison threshold, and before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method further includes:

[0081] Determine the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group, and the peak amplitude of the first attenuated wave when the response voltage wave in the response voltage wave group initially attenuates;

[0082] Determine a peak amplitude attenuation difference between a maximum value of the peak amplitude of the response wave and a peak amplitude of the attenuated first wave;

[0083] Based on the peak amplitude attenuation difference, it is determined whether a first hysteresis comparison threshold of the first hysteresis comparator meets the requirement.

[0084] Optionally, the acoustic wave feature detection unit includes a second hysteresis comparator, the second hysteresis comparator has a second hysteresis comparison threshold, and before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method further includes:

[0085] Determine the maximum value of the waveform intercept of the response voltage wave in the response voltage wave group, and the attenuation waveform intercept value of the attenuation first wave of the response voltage wave in the response voltage wave group when the response voltage wave initially attenuates;

[0086] Determine the intercept attenuation difference between the maximum value of the waveform intercept of the response voltage wave and the intercept value of the decayed waveform of the decayed first wave;

[0087] Based on the intercept attenuation difference, it is determined whether a second hysteresis comparison threshold of the second hysteresis comparator meets the requirement.

[0088] In a third aspect, an embodiment of the present application provides a device, which includes a device for measuring the acoustic wave transit time as described in any one of the first aspects above.

[0089] In an embodiment of the present application, an acoustic wave characteristic detection unit is provided, so that after the acoustic wave characteristic detection unit detects the attenuation of the peak value or waveform intercept of the response voltage wave, the acoustic wave characteristic detection unit sends an attenuation mark signal to the flight time measurement unit and the control module, so that the flight time measurement unit determines the stop time of the acoustic wave flight, and this stop time is an accurate time, and the start time of the acoustic wave flight is accurate, so that based on the accurate start time and the accurate stop time, the flight time of the acoustic wave flight can be accurately determined, and then the corresponding other parameters can be more accurately determined according to the flight time of the acoustic wave flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 A circuit connection diagram showing a method of detecting a wave peak amplitude based on a dual comparator and an acoustic wave feature detection unit provided in an embodiment of the present application;

[0091] Figure 2 A waveform diagram and a related definition diagram showing a response voltage wave group of a transducer response and a capacitive coupling output provided by an embodiment of the present application;

[0092] Figure 3 A waveform diagram showing a noise voltage greater than a comparison reference voltage of a comparator in the related art;

[0093] Figure 4 A waveform diagram showing that a comparison reference voltage of a comparator in the related art is greater than a peak amplitude of a first wave of a response voltage wave;

[0094] Figure 5 A circuit connection diagram showing a sound wave feature detection based on waveform intercept provided in an embodiment of the present application;

[0095] Figure 6 A waveform diagram showing the working principle of a response wave attenuation first wave detection based on wave peak amplitude detection provided in an embodiment of the present application;

[0096] Figure 7 A waveform diagram showing the working principle of the first wave detection of response wave attenuation based on waveform intercept detection provided in an embodiment of the present application;

[0097] Figure 8 A circuit connection diagram showing a sound wave feature detection unit for detecting a wave peak amplitude provided in an embodiment of the present application;

[0098] Fig. 9 A circuit connection diagram showing a sound wave feature detection unit for detecting peak amplitude and peak amplitude attenuation provided by an embodiment of the present application;

[0099] Fig.10 A circuit connection diagram showing a flight time measurement unit provided in an embodiment of the present application;

[0100] Fig.11 A schematic diagram showing a data cache unit of a flight time measurement unit provided in an embodiment of the present application;

[0101] Fig.12 A circuit connection diagram showing a circuit for detecting a wave peak amplitude based on a single comparator and an acoustic wave feature detection unit provided in an embodiment of the present application;

[0102] Fig.13 A circuit connection diagram for detecting a waveform intercept based on a dual comparator and an acoustic wave feature detection unit provided in an embodiment of the present application is shown;

[0103] Fig.14 One of the circuit connection diagrams of an acoustic wave feature detection unit for detecting waveform intercept and waveform intercept attenuation provided in an embodiment of the present application is shown;

[0104] Fig.15 A circuit connection diagram showing an acoustic wave feature detection unit for detecting a waveform intercept provided in an embodiment of the present application;

[0105] Fig.16 A circuit connection diagram showing a sound wave feature detection unit based on a dual comparator and a detection peak amplitude for distance measurement provided in an embodiment of the present application;

[0106] Fig.17 A circuit connection diagram showing a sound wave feature detection unit based on a single comparator and a detection peak amplitude for distance measurement provided in an embodiment of the present application;

[0107] Fig.18 A circuit connection diagram showing a sound wave feature detection unit based on a dual comparator and a detection waveform intercept for distance measurement provided by an embodiment of the present application;

[0108] Fig.19 A circuit connection diagram showing a sound wave feature detection unit for detecting wave peak amplitude based on a dual comparator, a duplex transducer and a wave peak amplitude for distance measurement provided by an embodiment of the present application;

[0109] Fig. 20 A circuit connection diagram showing a single comparator, a duplex transducer and an acoustic wave feature detection unit for detecting wave peak amplitude for distance measurement provided in an embodiment of the present application;

[0110] Fig.21 A circuit connection diagram showing a sound wave feature detection unit for distance measurement based on a dual comparator, a duplex transducer and a waveform intercept detection unit provided in an embodiment of the present application;

[0111] Fig. 22 A flow chart showing a method for measuring flight time provided in an embodiment of the present application.

[0112] Reference numerals:

[0113] 10: control module; 101: controller; 102: integrated control unit; 20: pulse generating unit; 30: transducer assembly; 31: first transducer; 32: second transducer; 33: third transducer; 40: acoustic wave characteristic detection unit; 401: first peak detector; 402: first analog-to-digital converter; 403: first register; 404: second register; 405: third register; 411: second peak detector; 412: third peak Detector; 413: first hysteresis comparator; 414: second analog-to-digital converter; 415: fourth register; 416: fifth register; 417: sixth register; 418: seventh register; 421: first waveform intercept detection unit; 422: sub-comparator; 423: gate; 424: eighth register; 425: second hysteresis comparator; 426: ninth register; 427: tenth register; 428: eleventh register; 429: twelfth register Register; 430: thirteenth register; 431: first control unit; 441: second control unit; 442: second waveform intercept detection unit; 50: flight time measurement unit; 51: third control unit; 52: time measurement unit; 53: data cache unit; 531: first cache register group; 532: second cache register group; 533: third cache register group; 60: comparator component; 61: first comparator; 62: second comparator; 63: third comparator; 70: reference voltage generating unit; 80: pulse counting unit; 90: first output buffer; 100: second output buffer; 110: measuring tube; 120: third output buffer; 130: analog selector; 140: first coupling capacitor; 150: second coupling capacitor; 160: bus interface unit; 170: timer unit; 180: interrupt control unit; 190: other functional units; 200: third coupling capacitor. DETAILED DESCRIPTION

[0114] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0115] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0116] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0117] like Figures 1 to 21 As shown, the acoustic wave flight time measuring device includes: a control module 10, a pulse generating unit 20, a transducer assembly 30, an acoustic wave characteristic detecting unit 40, a flight time measuring unit 50 and a comparator assembly 60;

[0118] The flight time measurement unit 50, the acoustic wave characteristic detection unit 40, and the pulse generating unit 20 are all electrically connected to the control module 10; the pulse generating unit 20 is electrically connected to the transducer assembly 30, the comparator assembly 60 and the flight time measurement unit 50, respectively; the transducer assembly 30 is electrically connected to the comparator assembly 60, the comparator assembly 60 is electrically connected to the acoustic wave characteristic detection unit 40 and the flight time measurement unit 50, the acoustic wave characteristic detection unit 40 is electrically connected to the transducer assembly 30, the flight time measurement unit 50 and the control module 10, respectively; the transducer assembly 30 is used to generate and transmit an acoustic wave group, and / or receive an acoustic wave group. The pulse generating unit 20 is used to generate an initial pulse group, which can be transmitted to the flight time measuring unit 50, the comparator component 60 and the transducer component 30. The flight time measuring unit 50 is used to determine the start time of the acoustic wave flight when receiving the initial pulse group. The transducer component 30 is used to stimulate the transducer component 30 to generate and emit an ultrasonic wave group when receiving the initial pulse group. The transducer component 30 is also used to generate a response voltage wave group when receiving the acoustic wave group. The response voltage wave group can be transmitted to the acoustic wave characteristic detection unit 40 and the comparator component 60; the acoustic wave characteristic detection unit 40 is used to detect the peak of the response voltage wave. The detection result is sent to the control module 10, and the control module 10 determines whether the peak amplitude or waveform intercept of the response voltage wave is attenuated; or, the acoustic wave feature detection unit 40 detects the peak amplitude or waveform intercept of the response voltage wave, and determines whether the peak amplitude or waveform intercept of the response voltage wave is attenuated; when it is determined that the peak amplitude of the response voltage wave is attenuated or the waveform intercept is attenuated, the flight time measurement unit 50 stops the current wave group measurement and determines the stop time of the acoustic wave flight. The flight time measurement unit 50 or the control module 10 determines the flight time of the acoustic wave group according to the start time and stop time of the acoustic wave flight.

[0119] It should be noted that the initial pulse group generated by the pulse generating unit 20 is usually a periodic square wave or rectangular wave pulse. Of course, the initial pulse group generated by the pulse generating unit 20 can also be a periodic triangle wave. The specific type of the initial pulse group generated by the pulse generating unit 20 is not limited in the embodiment of the present application. For the sake of convenience, the embodiment of the present application takes the initial pulse group generated by the pulse generating unit 20 as a periodic square wave to illustrate the principle of the invention. Correspondingly, the ultrasonic group and the response voltage wave are quasi-sine waves.

[0120] In addition, in the embodiment of the present application, the acoustic wave characteristic detection unit 40 can be used to detect whether the peak amplitude or waveform intercept of the response voltage wave in the response voltage wave group is attenuated, and the control module 10 can also be used to detect whether the peak amplitude or waveform intercept of the response voltage wave in the response voltage wave group is attenuated. Among them, when the peak amplitude or waveform intercept of the response voltage wave in the response voltage wave group is detected by the acoustic wave characteristic detection unit 40, the acoustic wave characteristic detection unit 40 sends the detected peak amplitude or waveform intercept to the control module 10, and the control module 10 determines whether the peak amplitude or waveform intercept is attenuated. Once the control module 10 determines that the waveform amplitude or waveform intercept is attenuated, the control module 10 controls the flight time measurement unit 50 to stop the current wave group measurement; when the waveform peak value or waveform intercept of the response voltage wave is detected by the acoustic wave characteristic detection unit 40, and it is determined whether the peak amplitude or waveform intercept is attenuated, once the acoustic wave characteristic detection unit 40 determines that the peak amplitude or waveform intercept is attenuated, the acoustic wave characteristic detection unit 40 sends an attenuation flag signal to the flight time measurement unit 50, and the attenuation flag signal includes a peak amplitude attenuation flag signal or a waveform intercept attenuation flag signal. When the flight time measurement unit 50 receives the attenuation flag signal, it stops the current wave group measurement.

[0121] In addition, if Fig.10 As shown, the waveform intercept refers to: at a position higher than the zero-crossing voltage of the response voltage wave, a straight line parallel to the horizontal coordinate axis of the response voltage wave intersects with the waveform of the response voltage wave. In any propagation period of the response voltage wave, the distance between the two points where the response voltage wave intersects with the straight line is, for example, at a position 0.5 times the peak-to-peak voltage of the response voltage wave, a straight line parallel to the horizontal coordinate axis of the response voltage wave intersects with the waveform of the response voltage wave. In any propagation period of the response voltage wave, the distance between the two points where the response voltage wave intersects with the straight line is the waveform intercept. Where, Figure 2 As shown, the zero-crossing voltage value refers to: the voltage value at the position where the positive wave and the negative wave of the response voltage wave are sheared. The response voltage wave can be a response voltage wave directly generated by the transducer assembly; in addition, when the flight time measurement device includes a coupling capacitor, the coupling capacitor is electrically connected to the transducer assembly, and the response voltage wave generated by the transducer assembly is transmitted to the coupling capacitor, and coupled by the coupling capacitor to form a coupled response voltage wave. That is, the response voltage wave in the definition of the zero-crossing voltage value can be a response voltage wave directly generated by the transducer assembly, and can also be a response voltage wave coupled by a coupling capacitor.

[0122] In the embodiment of the present application, since the flight time measurement unit 50, the acoustic wave characteristic detection unit 40, and the pulse generating unit 20 are all electrically connected to the control module 10, the flight time measurement unit 50, the acoustic wave characteristic detection unit 40, and the pulse generating unit 20 can be controlled by the control module 10, or send signals to the control module 10, or the control module 10 can collect required data from the flight time measurement unit 50 and the acoustic wave characteristic detection unit 40. Since the pulse generating unit 20 is electrically connected to the transducer assembly 30, the comparator assembly 60, and the flight time measurement unit 50, respectively, once the pulse generating unit 20 generates an initial pulse group, the initial pulse group can be transmitted to the flight time measurement unit 50, the comparator assembly 60, and the transducer assembly 30. After the initial pulse group is transmitted to the comparator assembly 60, the comparator assembly 60 can continue to transmit the initial pulse group to the flight time measurement unit 50, so that the flight time measurement unit 50 can use the time of receiving the initial pulse group as the start time of the acoustic wave flight. After receiving the initial pulse group, the transducer assembly 30 can be excited so that the transducer assembly 30 generates an acoustic wave group, and the transducer assembly 30 generates a response voltage wave group when receiving the acoustic wave group. Since the transducer assembly 30 is electrically connected to the comparator assembly 60, the comparator assembly 60 is electrically connected to the acoustic wave characteristic detection unit 40, and the acoustic wave characteristic detection unit 40 is electrically connected to the transducer assembly 30, the flight time measurement unit 50 and the control module 10, once the transducer assembly 30 generates a response voltage wave group, the response voltage wave group can be transmitted to the acoustic wave characteristic detection unit 40 and the comparator assembly 60. After receiving the response voltage wave group, the comparator assembly 60 can compare and output a comparison pulse to the flight time measurement unit 50. The essence of the comparison pulse is to convert the quasi-sine wave of the response voltage wave group into a rectangular pulse that can be measured by flight and transmit it to the flight time measurement unit 50 for flight time measurement, and the acoustic wave characteristic detection unit 40 can perform real-time detection on the response voltage wave group. The acoustic wave characteristic detection unit 40 detects the peak amplitude or waveform intercept of the response voltage wave group and determines whether the peak amplitude or waveform intercept is attenuated, or the acoustic wave characteristic detection unit 40 detects the peak amplitude or waveform intercept and sends the detected peak amplitude or waveform intercept to the control module 10, and the control module 10 determines whether the peak amplitude or waveform intercept is attenuated. Once it is determined that the waveform amplitude or waveform intercept is attenuated, the flight time measurement unit 50 immediately stops the current wave group measurement, and a time point before the time when the acoustic wave characteristic detection unit 40 detects the peak amplitude attenuation or waveform intercept attenuation of the response voltage wave group is used as the stop time of the acoustic wave flight. After determining the start time and end time of the flight time measurement, the flight time of the acoustic wave group can be determined.

[0123] That is, in the embodiment of the present application, by setting up the acoustic wave characteristic detection unit 40 and the control module 10, it is possible to determine whether the peak amplitude or the waveform intercept is attenuated through the acoustic wave characteristic detection unit 40 or the control module 10. Once it is determined that the peak amplitude or the waveform intercept begins to attenuate, the flight time measurement unit 50 determines the stop time of the acoustic wave flight. This stop time is an accurate time, and the start time of the acoustic wave flight is accurate. Therefore, based on the accurate start time and the accurate stop time, the flight time of the acoustic wave flight can be accurately determined, and then the corresponding other parameters can be more accurately determined according to the flight time of the acoustic wave flight.

[0124] It should be noted that after the pulse generating unit 20 generates the initial pulse group, the initial pulse group is transmitted to the transducer assembly 30, which can excite the transducer assembly 30 to generate a sound wave group. The transducer assembly 30 that is not driven by the pulse generating unit 20 generates a response voltage wave group after receiving the sound wave group. The response voltage wave in the response voltage wave group is a mechanical wave, and is a quasi-sine wave. In this process, that is, the initial pulse group is transmitted to the transducer assembly 30, the transducer assembly 30 generates and emits a sound wave group, and the sound wave group is transmitted to the transducer assembly 30, so that the transducer assembly 30 that is not driven by the pulse generating unit 20 generates a response voltage wave group, which is equivalent to the initial pulse group continuously exciting the transducer assembly 30. When the transducer assembly 30 is initially excited, the peak amplitude or waveform intercept of the response voltage wave in the generated response voltage wave group must gradually increase until the transducer assembly 30 and the pulse generating unit 20 produce a resonance-like phenomenon, and the peak amplitude or waveform intercept of the response voltage wave in the response voltage wave group remains unchanged, and the peak amplitude or waveform intercept reaches a maximum value. Once the pulse generating unit 20 stops generating the initial pulse group, it is equivalent to stopping the energy output to the transducer assembly 30, so that the response voltage wave in the response voltage wave group generated by the transducer assembly 30 will inevitably begin to decay, that is, the peak amplitude or waveform intercept of the response voltage wave will inevitably begin to decay, and the acoustic wave characteristic detection unit 40 sends an attenuation mark signal to the control module 10 and the flight time measurement unit 50 when detecting that the peak amplitude or waveform intercept of the response voltage wave begins to decay, and the flight time measurement unit 50 immediately stops measuring and determines the stop time. The stop time can be a time point before the peak amplitude or waveform intercept of the response voltage wave begins to decay. For example, in the process of transmitting the response voltage wave, if the response voltage wave begins to decay, the time of the response voltage wave within a transmission cycle adjacent to the time of the start of decay before the start of decay can be used as the stop time.

[0125] Since the peak amplitude or waveform intercept of the response voltage wave will inevitably decay after the initial pulse group is emitted, the event of the attenuation of the peak amplitude or waveform intercept of the response voltage wave is certain, and the first wave of decay can be accurately detected. Therefore, the flight time measurement unit 50 can accurately determine the stop time of the sound wave flight, and the time when the flight time measurement unit 50 receives the initial pulse group is also accurate, that is, the start time determined by the flight time measurement unit 50 is accurate, so based on the accurate start time and the accurate stop time, the flight time of the sound wave flight can be accurately determined.

[0126] It should be noted that, in the embodiment of the present application, the transducer assembly 30 is an energy conversion device that can work bidirectionally, and can both emit sound waves and receive sound waves. That is, after the transducer assembly 30 driven by the pulse generating unit 20 receives the initial pulse group, the transducer assembly 30 can be excited so that the transducer assembly 30 generates a sound wave group, and the transducer assembly 30 not driven by the pulse generating unit 20 will generate a response voltage wave group when receiving the sound wave group.

[0127] In addition, in some embodiments, Fig.15 As shown, the measuring device for the acoustic wave flight time may further include a first output buffer 90 and a second output buffer 100, and the transducer assembly 30 includes a first transducer 31 and a second transducer 32; the first output buffer 90 is electrically connected to the pulse generating unit 20 and the first transducer 31, respectively, and the second output buffer 100 is electrically connected to the pulse generating unit 20 and the second transducer 32, respectively; when one of the first transducer 31 and the second transducer 32 is used as an excitation transducer, the other is used as a response transducer, and when the first output buffer 90 is configured as an output state and the second output buffer 100 is configured as a cut-off state, the first output buffer 90 provides an excitation voltage and a current for the first transducer 31, so that the first transducer 31 is used as an excitation transducer. transducer, the second transducer 32 acts as a response transducer, the first transducer 31 generates and transmits a sound wave group, the second transducer 32 receives the sound wave group and generates a response voltage wave group, and the response transducer is electrically connected to the comparator component 60 and the sound wave feature detection unit 40; when the second output buffer 100 is configured to the output state and the first output buffer 90 is configured to the cut-off state, the second output buffer 100 provides an excitation voltage and current to the second transducer 32, so that the second transducer 32 acts as an excitation transducer, the first transducer 31 acts as a response transducer, the second transducer 32 generates and transmits a sound wave group, the first transducer 31 receives the sound wave group and generates a response voltage wave group, and the response transducer is electrically connected to the comparator component 60 and the sound wave feature detection unit 40.

[0128] Since the first output buffer 90 is electrically connected to the pulse generating unit 20 and the first transducer 31 respectively, and the second output buffer 100 is electrically connected to the pulse generating unit 20 and the second transducer 32 respectively, the function of the first transducer 31 and the function of the second transducer 32 can be switched by configuring the states of the first output buffer 90 and the second output buffer 100. Specifically, when the first output buffer 90 is configured to be in the output state and the second output buffer 100 is configured to be in the cut-off state, the first output buffer 90 can provide the excitation voltage and current to the first transducer 31, and the second output buffer 100 does not provide the excitation voltage and current to the second transducer 32, so that the first transducer 31 is excited, the first transducer 31 acts as an excitation transducer, and the second transducer 32 acts as a response transducer, and the first transducer 31 generates and transmits a sound wave group. After the sound wave group is transmitted, the second transducer 32 can receive the sound wave group and generate a response voltage wave group, and the response transducer is electrically connected to the comparator component 60 and the sound wave feature detection unit 40, so that the response voltage group can be transmitted to the comparator component 60 and the sound wave feature detection unit 40. 0; when the second output buffer 100 is configured as the output state and the first output buffer 90 is configured as the cut-off state, the second output buffer 100 can provide the second transducer 32 with an excitation voltage and current, and the first output buffer 90 does not provide the second transducer 32 with an excitation voltage and current, so that the second transducer 32 is excited, the second transducer 32 acts as an excitation transducer, and the first transducer 31 acts as a response transducer, and the second transducer 32 generates and transmits a sound wave group. After the sound wave group is transmitted, the first transducer 31 can receive the sound wave group and generate a response voltage wave group, and the response transducer is electrically connected to the comparator component 60 and the sound wave feature detection unit 40, so that the response voltage wave group can be transmitted to the comparator component 60 and the sound wave feature detection unit 40.

[0129] It should be noted that in the embodiment of the present application, the distance can be measured by using the measuring device of the acoustic wave flight time. At this time, the first output buffer 90 can provide the excitation voltage and current to the first transducer 31, and the second output buffer 100 is in the cut-off state. The first transducer 31 acts as an excitation transducer, and the second transducer 32 acts as a response transducer. After the excitation transducer emits the sound wave, the sound wave is transmitted to the obstacle, and the sound wave is blocked by the obstacle, so that the sound wave is transmitted to the response transducer, and the response transducer can generate a response voltage wave. In the embodiment of the present application, the flight time of the sound wave can be accurately determined, and the speed of the sound wave transmission in the current medium can be used to accurately determine the distance between the excitation transducer and the obstacle. For example, the measuring device of the acoustic wave flight time in the embodiment of the present application is installed on a vehicle, a ship, or a submarine, so that the distance between the measuring device of the acoustic wave flight time and the obstacle can be more accurately determined.

[0130] In addition, in the embodiments of the present application, Fig.13 As shown, the acoustic wave transit time measuring device may further include a measuring tube 110; the excitation transducer is disposed at a first end of the measuring tube 110, and the response transducer is disposed at a second end of the measuring tube 110. The measuring tube may be filled with fluid.

[0131] Through such a setting, after the excitation transducer emits a sound wave, the sound wave flies and transmits in the fluid in the measuring tube 110, and then the response transducer can receive the sound wave, so that the response transducer generates a response voltage wave group. Through the sound wave flight time measurement device in the embodiment of the present application, the sound wave flight time can be accurately determined, and then the flow rate of the fluid in the measuring tube 110 can be accurately determined, so as to more accurately determine parameters such as flow rate.

[0132] It should be noted that when the device for measuring the acoustic wave flight time includes the measuring tube 110, the flow rate of the fluid in the measuring tube 110 can also be accurately determined, and then parameters such as the flow rate can be more accurately determined. Therefore, the measuring device provided in the embodiment of the present application can be applied to the water meter, and parameters such as the flow rate and flow rate of the tap water flowing through the measuring tube 110 can be determined more accurately.

[0133] In addition, in some embodiments, Fig.19 As shown, the device for measuring the acoustic wave flight time may further include a third output buffer 120, and the transducer assembly 30 includes a third transducer 33; the third output buffer 120 is electrically connected to the pulse generating unit 20 and the third transducer 33 respectively, and the third transducer 33 is electrically connected to the comparator assembly 60 and the acoustic wave characteristic detecting unit 40; when the third output buffer 120 is configured to be in the output state, the third output buffer 120 provides the third transducer 33 with an excitation voltage and current, and the third transducer 33 generates and transmits an acoustic wave group; when the third output buffer 120 is configured to be in the cut-off state, the third output buffer 120 stops providing the third transducer 33 with an excitation voltage and current, and the third transducer 33 can receive the acoustic wave group and generate a response voltage wave group.

[0134] By setting the third output buffer 120, the third transducer 33 can be switched between different working conditions by adjusting the state of the third output buffer 120, thereby realizing different functions. Specifically, when the third output buffer 120 is configured as an output state, the third output buffer 120 can provide an excitation voltage and current for the third transducer 33, and the third transducer 33 is used as an excitation transducer, and the third transducer 33 generates and transmits a sound wave group; when the third output buffer 120 is configured as a cut-off state, the third output buffer 120 stops providing an excitation voltage and current for the third transducer 33, and the third transducer 33 is used as a response transducer, and the third transducer 33 can receive a sound wave group and generate a response voltage wave group. That is, by setting the state of the third output buffer 120, the third transducer 33 can transmit a sound wave group, and the third transducer 33 can also receive a sound wave group, so that the transmission and reception of the sound wave group can be realized through a single transducer, which is conducive to reducing costs.

[0135] Among them, the distance measurement can be performed through the sound wave flight time measuring device of the embodiment of the present application. In a specific application, the third output buffer 120 can be first configured to be in a driving state, that is, the third output buffer 120 provides an excitation voltage and current to the third transducer 33, and the third transducer 33 emits a sound wave group. Then, the third output buffer 120 can be configured to be in a cut-off state. After the sound wave group collides with an obstacle, it will be blocked, so that the sound wave group is reflected to the third transducer 33, and the third transducer 33 can receive the sound wave group and generate a response voltage wave group. In the present application, the sound wave flight time can be determined more accurately, so that the distance between the sound wave flight time measuring device and the obstacle can be determined more accurately.

[0136] In the related art, when measuring the flight time of a sound wave group, a measuring device is also used. The measuring device includes a control module 10, a flight time measurement unit 50, a pulse generating unit 20, an excitation transducer, a response transducer, a comparator and a measuring tube 110. The excitation transducer and the response transducer are arranged at both ends of the measuring tube 110. The flight time measurement unit 50 is electrically connected to the pulse generating unit 20 and the excitation transducer, the response transducer is electrically connected to the comparator, the comparator is electrically connected to the flight time measurement unit 50, and the flight time measurement unit 50 is electrically connected to the control module 10. The measuring principle of the measuring device is as follows: the pulse generating unit 20 generates a pulse, which is transmitted to the flight time measuring unit 50. After the flight time measuring unit 50 receives the pulse, it determines the start time of the ultrasonic wave flight. After the pulse is transmitted to the excitation transducer, the excitation transducer generates an ultrasonic wave group, which is transmitted to the response transducer, and the response transducer excites and generates a response voltage wave group, which is transmitted to the comparator. Before measuring a sound wave group, the comparison reference voltage of the comparator is set to a threshold value greater than the zero-crossing voltage value for non-zero comparison, so as to filter out the noise wave generated by the environmental noise and then transmit it to the comparator and then to the flight time measuring unit 50, so as to avoid misdetection, so as to reliably detect the first wave of the head wave of the response wave group. After the response voltage wave in the response voltage wave group is transmitted to the comparator, when the voltage of the response voltage wave in the response voltage wave group is greater than the bias threshold voltage, the comparator outputs a non-zero comparison pulse, referred to as the first wave non-zero comparison pulse. After the first wave of non-zero comparison pulses arrives, the comparison reference voltage of the comparator is automatically set to the comparison threshold voltage equal to the voltage value of the shear position of the positive and negative peaks of the response wave to perform zero-crossing comparison. After the comparator is set to zero-crossing comparison, the response voltage wave in the response voltage wave group is transmitted to the comparator. Since the original excitation pulse is a periodic square wave or rectangular wave, the comparator also outputs a periodic square wave or rectangular wave with the same period.

[0137] It usually takes multiple original excitation pulse cycles for the response transducer to vibrate and form a stable resonance. Therefore, in the related art, the detection of the flying stop time is set to the Nth zero-crossing comparison pulse after the arrival of the first wave of non-zero comparison pulses or the Nth zero-crossing comparison pulse and several consecutive zero-crossing comparison pulses thereafter, in order to achieve a stable flying stop time measurement, and then stop the flying time measurement and determine the flying stop time. Thus, the flying time of the sound wave group is determined based on the determined flying start time and one or more flying stop times.

[0138] However, in the related art, the measurement and determination of the stop time of the acoustic wave group flying is based on the detection of the first wave of non-zero comparison pulses, and the first wave of non-zero comparison pulses is used as a reference, and the stop time of the flying is determined by the subsequent Nth zero-crossing comparison pulse or the Nth zero-crossing comparison pulse and several consecutive zero-crossing comparison pulses thereafter. This is equivalent to assuming that the first wave of non-zero comparison pulses is the acoustic wave flying response pulse corresponding to the first pulse of the original excitation pulse, which has the following problems:

[0139] Question (1): Whether it is the excitation transducer or the response transducer, the process from oscillation to resonance is a process that requires continuous and sufficient energy input. For the sake of convenience, the excitation transducer and the response transducer are referred to as the transducer group. In the initial stage, the transducer group is still in the energy storage stage. Due to the differences in the technical performance indicators of the power supply system and the voltage-controlled oscillation characteristics of the transducer group of each measuring device and the differences in the individual devices, the energy injection speed of the transducer group and the time required for the transducer group to respond to oscillation are different. This leads to: first, the first wave of the sound wave group excited by the transmitting transducer may not be excited by the first pulse of the original excitation pulse; second, the first wave of the response voltage wave group generated by the receiving transducer receiving the sound wave group may not be excited by the first wave of the sound wave group emitted by the transmitting transducer, resulting in the first wave of non-zero comparison pulses not being the flyby response pulse of the sound wave excited by the first pulse of the original excitation pulse group, resulting in errors in the determination of the stop time of the sound wave flyby, and the error deviation is one or more original excitation pulse cycle times, which will lead to huge flyby time measurement errors.

[0140] Question (2): In the related art, the setting of the non-zero comparison threshold voltage is based on the experience of the device designer, while the working environment and working conditions of the measuring device vary greatly and are difficult to exhaust. If the non-zero comparison threshold voltage is set too large, the first response voltage wave generated by the head wave of the acoustic wave group will be missed by the comparator, which will erroneously cause the first wave of non-zero comparison pulses to be delayed by one or more original excitation pulse cycles; if the non-zero comparison threshold voltage is set too small, the noise of the response voltage wave group introduced by the environmental noise exceeds the non-zero comparison threshold voltage, and the comparator will malfunction due to the voltage wave noise, which will erroneously cause the first wave of non-zero comparison pulses to be advanced. Regardless of whether the first wave of non-zero comparison pulses is erroneously delayed or advanced, it will result in an error in the measurement and determination of the acoustic wave flight stop time. For example, Figure 3 and Figure 4 As shown, in Figure 3 In the case of non-zero comparison threshold voltage being too small, the comparator malfunctions due to voltage wave noise. Figure 4 In the case of a non-zero comparison threshold voltage being too large, the first response voltage wave generated by the head wave of the sound wave group is missed by the comparator.

[0141] Question (3): The transducer group used in the measuring device, on the one hand, the emission characteristics and response characteristics of the transducer group will show performance degradation as the use time and frequency of use increase; on the other hand, the transducer group will be scaled due to various impurities in the measured fluid, which will also cause the emission characteristics and response characteristics of the transducer group to decay. Whether the excitation performance of the transmitting transducer decays or the response performance of the response transducer decays, the configured non-zero comparison threshold voltage becomes relatively high, which will cause the non-zero comparison pulse of the first wave of the detected response wave group to be delayed compared to the non-zero comparison pulse of the first wave under normal circumstances, thereby causing the non-zero comparison pulse of the first wave of the detected response wave group to be not the response pulse after the acoustic wave flight excited by the first pulse of the original excitation pulse group, which in turn causes the measurement and determination of the stop time of the acoustic wave flight to be wrong.

[0142] Therefore, the related technology based on the detection of the non-zero comparison pulse of the first wave of the response voltage wave group and the measurement method based on the detection of the non-zero comparison pulse of the first wave of the response voltage wave group to determine the stop time and the flying time of the sound wave has obvious defects.

[0143] In the embodiment of the present application, the peak amplitude or waveform intercept of the response voltage wave in the response voltage wave group is detected by the acoustic wave characteristic detection unit 40, and the peak amplitude or waveform intercept of the response voltage wave will inevitably decay, which is determined to be constant. Therefore, in the embodiment of the present application, the stop time of the acoustic wave flight determined by the flight time measurement unit 50 is accurate, and the start time of the acoustic wave flight determined by the flight time measurement unit 50 is also accurate, so that the determined flight time of the acoustic wave flight is accurate. That is, in the embodiment of the present application, even if there is noise in the environment and noise waves are generated, the noise waves will not affect the attenuation of the response voltage wave. This is because the response voltage wave is generated by the initial pulse group generated by the pulse generator, and as the initial pulse group continues to be transmitted to the excitation transducer, the excitation transducer continues to generate an ultrasonic wave group, which continues to be transmitted to the response transducer. The ultrasonic wave group continues to provide response oscillation energy for the response transducer, and then the response transducer will continue to generate a response voltage wave group. In this process, the peak amplitude or waveform intercept of the response voltage wave group continues to increase until it increases to a certain amount, and then it will remain unchanged. When the pulse generator stops generating pulses, it is equivalent to terminating the excitation of the excitation transducer, and the ultrasonic wave group generated by the excitation transducer will inevitably decay rapidly, which is equivalent to the ultrasonic wave group ceasing to provide response oscillation energy for the response transducer, and thus the peak amplitude or waveform intercept of the response voltage wave generated by the response transducer will inevitably decay. That is, in the embodiment of the present application, the peak amplitude or waveform intercept attenuation of the response voltage wave is bound to exist, and the present application determines the stop time of the acoustic wave flight based on this inevitable deterministic event, so that the stop time is accurate, and then based on the accurate start time and the accurate stop time, the determined flight time of the acoustic wave flight is accurate, which is facilitating the subsequent determination of the flow velocity, flow rate and other parameters of the fluid in the measuring tube 110 or the determination of the distance between the measuring device and the obstacle based on the accurate flight time of the acoustic wave flight.

[0144] It should be noted that in the embodiment of the present application, the pulse generating unit 20 is electrically connected to the flight time measurement unit 50, and the pulse generating unit 20 is electrically connected to the comparator component 60 respectively, and the comparator component 60 is electrically connected to the flight time measurement unit 50. Therefore, after the pulse generating unit 20 generates an initial pulse group, the initial pulse group can be directly transmitted to the flight time measurement unit 50, and the initial pulse group can also be transmitted to the comparator component 60, and then transmitted to the flight time measurement unit 50 through the comparator component 60.

[0145] If the initial pulse group is directly transmitted to the flight time measurement unit 50 as the first transmission path of the initial pulse group, and the initial pulse group is transmitted to the flight time measurement unit 50 after passing through the comparator component 60 as the second transmission path of the initial pulse group, in the embodiment of the present application, the time when the flight time measurement unit 50 receives the initial pulse group can be the time when it is transmitted to the flight time measurement unit 50 through the first transmission path, or the time when it is transmitted to the flight time measurement unit 50 through the second transmission path. That is, in the embodiment of the present application, the initial pulse group generated by the pulse generating unit 20 can be directly transmitted to the flight time measurement unit 50, and the flight time measurement unit 50 determines the start time of the acoustic wave flight after receiving the initial pulse group; the initial pulse group generated by the pulse generating unit 20 can also be transmitted to the flight time measurement unit 50 after passing through the comparator component 60, and the flight time measurement unit 50 determines the start time of the acoustic wave flight after receiving the initial pulse group. The initial pulse group is essentially an electrical signal, and the propagation speed of the electrical signal is the same as the speed of light, which is much greater than the propagation speed of the sound wave. The propagation of the electrical signal in the device of the present invention is in the limited space of the device, so the propagation distance of the electrical signal is very short, so the propagation time of the electrical signal in the device of the present invention can be ignored. When the flight time measurement unit 50 receives the initial pulse group, whether it is the initial pulse group transmitted through the first transmission path or the initial pulse group transmitted through the second transmission path, the start time of the sound wave flight is accurate. In addition, between the first transmission path and the second transmission path, only the initial pulse group transmitted through one transmission path can be selected, so that the start time of the sound wave flight determined by the flight time measurement unit 50 is single. Specifically, if the first transmission path is used as the transmission path of the initial pulse group so that it transmits the initial pulse group to the flight time measurement unit 50, the initial pulse group can be not transmitted to the comparator component 60, which is equivalent to disconnecting the pulse generator and the comparator component 60; if the second transmission path is used as the transmission path of the initial pulse group so that it transmits the initial pulse group to the flight time measurement unit 50, the pulse generator and the flight time measurement unit 50 can be disconnected.

[0146] In addition, in the embodiment of the present application, because the pulses of the initial pulse group are periodic rectangular waves or square wave pulses, the flying time measurement unit 50 can use the time when the rising edge of the first pulse in the initial pulse group is transmitted to the flying time measurement unit 50 as the starting time of the acoustic wave flying. Of course, the time when the rising edges of other pulses in the initial pulse group except the first pulse are transmitted to the flying time measurement unit 50 can also be used as the starting time of the acoustic wave flying. In addition, in some embodiments, the time when the falling edge of the first pulse in the initial pulse group is transmitted to the flying time measurement unit 50 can also be used as the starting time of the acoustic wave flying. Of course, the time when the falling edges of other pulses in the initial pulse group except the first pulse are transmitted to the flying time measurement unit 50 can also be used as the starting time of the acoustic wave flying. In this regard, the embodiment of the present application is not limited here.

[0147] It should be noted that in the embodiments of the present application, sound waves may include infrasound waves, ultrasonic waves, sound waves perceptible to humans, etc., that is, the sound wave group generated by the excitation transducer may be an infrasound wave group, an ultrasonic wave group, a sound wave group perceptible to humans, etc.

[0148] In addition, in the embodiments of the present application, Figure 1 As shown, the control module 10 may include an integrated control unit 102 and a controller 101, the controller 101 may be a host computer or a central processing unit, the integrated control unit 102 is connected to the bus interface, and the bus interface is connected to the controller 101, thereby forming the control module 10. Among them, the controller 101 can send instructions to the integrated control unit 102 through the bus interface, and the integrated control unit 102 can control other components. Of course, other components can also be connected to the bus interface through the connection bus, so that the controller 101 directly controls other components, and other components refer to components that are electrically connected to the control module 10 and controlled by the control module 10. For example, other components include a pulse generating unit 20.

[0149] In addition, in some embodiments, Fig.10 As shown, the flight time measurement unit 50 may include a third control unit 51, a time measurement unit 52 and a data cache unit 53; the time measurement unit 52 is electrically connected to the third control unit 51 and the data cache unit 53 respectively, the third control unit 51 is electrically connected to the data cache unit 53, the time measurement unit 52 is used to detect the start time and the stop time, and the data cache unit 53 is used to cache the detected data; wherein the third control unit 51 is electrically connected to the control module 10.

[0150] Since the time measurement unit 52 is electrically connected to the third control unit 51 and the data cache unit 53 respectively, the time measurement unit 52 can detect the start time and stop time of the acoustic wave flying, and the time measurement unit 52 can transfer the start time to the third control unit 51, transfer the stop time to the third control unit 51, and transfer it to the data cache unit 53 when detecting the start time and stop time of the acoustic wave flying. Thus, after the third control unit 51 determines the start time and stop time, the third control unit 51 can control the time measurement unit 52 to stop detection, so that the flying time measurement unit 50 stops detecting the flying time of the acoustic wave flying, and the third control unit 51 can determine the flying time of the acoustic wave flying according to the start time and stop time. Of course, when the third control unit 51 determines the start time and stop time, the third control unit 51 can send both the start time and stop time to the control module 10, and the control module 10 determines the flying time of the acoustic wave flying according to the start time and stop time. And the data cache unit 53 can cache the data detected by the time measurement unit 52, so as to facilitate the subsequent reading of these data.

[0151] It should be noted that, in the embodiment of the present application, the flight time measurement unit 50 may be a time-to-digital converter (TDC). Of course, the flight time measurement unit 50 may also be other types, and any device that can measure time may be used. This is not limited in the embodiment of the present application. In the embodiment of the present application, the acoustic wave feature detection unit 40 for waveform intercept attenuation detection may be Fig.14 A composite type detector of waveform intercept detection and waveform intercept attenuation detection is shown.

[0152] In addition, in some embodiments, Fig.11 As shown, the data cache unit 53 can have at least two levels of cache register groups, and the at least two levels of cache register groups are electrically connected to the third control unit 51; the at least two levels of cache register groups include at least a first cache register group 531 and a second cache register group 532, and the first cache register group 531 and the second cache register group 532 are both electrically connected to the third control unit 51; when the peak amplitude or waveform intercept of the response voltage wave begins to decay, the first cache register group 531 is used to store the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the last initial pulse in the initial pulse group; the second cache register group 532 is used to store the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the second last initial pulse in the initial pulse group.

[0153] When the peak amplitude or waveform intercept of the response voltage wave begins to decay, it indicates that the pulse generating unit 20 has stopped generating pulses, and the last initial pulse in the initial pulse group generated by the pulse generating unit 20 has completed the excitation of the excitation transducer, and the response voltage wave in the response voltage wave group generated by the response transducer will begin to decay. In this case, the first buffer register group 531 stores the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the last initial pulse in the initial pulse group, and the second buffer register group 532 stores the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the second last initial pulse in the initial pulse group, so that the first buffer register group 531 and the second buffer register group 532 are equivalent to storing the stop time of two acoustic wave flyings, and the stop time of the acoustic wave flying can be determined according to the stop time of the two acoustic wave flyings. That is, by setting the first buffer register group 531 and the second buffer register group 532, at least two stop times of flying can be stored and cached, so as to facilitate the determination of the stop time of the acoustic wave flying.

[0154] It should be noted that before the response voltage wave starts to decay, that is, before the first wave of the decay of the response voltage wave arrives, the first buffer register group can store the stop time of the ultrasonic wave flying corresponding to the ultrasonic wave excited by the last initial pulse in the initial pulse group, that is, the stop time of the ultrasonic wave flying corresponding to the last response voltage wave cycle, and the second buffer register group can also store the stop time of the ultrasonic wave flying corresponding to the ultrasonic wave excited by the second last initial pulse in the initial pulse group, that is, the stop time of the ultrasonic wave flying corresponding to the second last response voltage wave cycle. Therefore, when the first wave of the decay of the response voltage wave arrives, the first buffer register group has stored the stop time of the ultrasonic wave flying corresponding to the last response voltage wave cycle that has passed, that is, the stop time of the ultrasonic wave flying excited by the last excitation pulse, and the second buffer register group has stored the stop time of the ultrasonic wave flying corresponding to the last response voltage wave cycle that has passed, that is, the stop time of the ultrasonic wave flying excited by the second last excitation pulse.

[0155] It should be noted that, in the embodiment of the present application, at least two levels of cache register groups may include multiple levels of cache register groups, for example, at least two levels of cache register groups include a first cache register group 531, a second cache register group 532, and a third cache register group 533. The role of the third cache register group 533 can refer to the role of the first cache register group 531. Specifically, the third cache register group 533 stores the ultrasonic wave flying stop time corresponding to the third last response voltage wave cycle that has passed, that is, the ultrasonic wave flying stop time excited by the third last excitation pulse. When the number of cache register groups in the cache register group in the at least two levels of cache register groups is greater than three, the first cache register group 531, the second cache register group 532, the third cache register group 533 can be used for storage, and so on, which will not be repeated here.

[0156] In addition, in some embodiments, Figure 1 As shown, the device for measuring the acoustic wave flight time may further include a reference voltage generating unit 70. The reference voltage generating unit 70 is electrically connected to the control module 10 and the comparator component 60, respectively, and the reference voltage generating unit 70 is used to provide a comparison reference voltage to the comparator component 60, wherein the comparison reference voltage is a voltage greater than or equal to the zero-crossing voltage value.

[0157] By setting the reference voltage generating unit 70, the control module 10 can control the reference voltage generating unit 70 to provide a comparison reference voltage to the comparator component 60, and the comparator component 60 has a comparison reference terminal, and the reference voltage generating unit 70 can be electrically connected to the comparison reference terminal. Once the reference voltage generating unit 70 generates a comparison reference voltage, the comparison reference voltage can be transmitted to the comparison reference terminal, so that once the voltage of the input signal terminal of the comparator component 60 is greater than the voltage of the comparison reference terminal, the comparator component 60 will output a comparison pulse. That is, by setting the reference voltage generating unit 70, it is convenient for the comparator component 60 to compare the voltage of its input signal terminal with the voltage of the comparison reference terminal to determine whether to output a comparison pulse.

[0158] It should be noted that the comparator component 60 is electrically connected to the transducer component 30, so that the response voltage wave generated by the transducer component 30 will be transmitted to the comparator component 60, and the comparator component 60 will compare the voltage of the response voltage wave with the voltage of the comparison reference end. If the voltage of the response voltage wave is greater than the voltage of the comparison reference end, the comparator component 60 outputs a comparison pulse. If the voltage of the response voltage wave is less than the voltage of the comparison reference end, the comparator component 60 does not output a comparison pulse.

[0159] In addition, in the embodiment of the present application, the comparator component 60 may be of different types, and two types are taken as examples for description below:

[0160] Type (1): e.g. Fig.12 As shown, the comparator component 60 may include a first comparator 61. The first comparator 61 is electrically connected to the reference voltage generating unit 70, the flight time measuring unit 50, the acoustic wave characteristic detecting unit 40, the transducer component 30, and the pulse generating unit 20 respectively; the response voltage wave group transmitted to the first comparator 61 can be transmitted to the flight time measuring unit 50, and the control module 10 controls the reference voltage generating unit 70 to provide the first comparator 61 with a comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, so that the first comparator 61 performs a non-zero comparison on the response voltage wave group, and when the peak value of the response voltage wave is higher than the comparison reference voltage, the first comparator 61 outputs a non-zero comparison pulse, and after one or more non-zero comparison pulses are output, the control module 10 controls the reference voltage generating unit 70 to provide the first comparator 61 with a comparison reference voltage equal to the zero-crossing voltage value of the compared response voltage wave group, so that the first comparator 61 performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse until the measurement process ends.

[0161] Since the first comparator 61 is electrically connected to the transducer assembly 30, the transducer assembly 30 can transmit the generated response voltage wave group to the first comparator 61, and the first comparator 61 is also electrically connected to the reference voltage generating unit 70, the control module 10 can control the reference voltage generating unit 70 to provide the first comparator 61 with a comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, so that the first comparator 61 will compare the response voltage wave with the comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, that is, perform a non-zero comparison on the response voltage wave group, and when the response voltage wave group is When the peak value of the response voltage wave is higher than the comparison reference voltage, the first comparator 61 will output a non-zero comparison pulse, and after the first comparator 61 outputs the non-zero comparison pulse, the control module 10 controls the reference voltage generating unit 70 to provide the first comparator 61 with a comparison reference voltage equal to the zero-crossing voltage value of the compared response voltage wave group, so that the first comparator 61 compares the peak value of the response voltage wave with the voltage of the zero-crossing voltage value of the compared response voltage wave group, that is, performs a zero-crossing comparison on the response voltage wave group, and the first comparator 61 outputs a zero-crossing comparison pulse until the measurement of the sound wave group flying is completed. That is, by setting the first comparator 61, the first comparator 61 can have a zero-crossing comparison function and a non-zero comparison function, which is equivalent to using only one comparator to complete the identification of the arrival of the response wave for the sound wave flying and the measurement of the flying time, thereby saving the number of comparators and reducing costs.

[0162] It should be noted that the first comparator 61 can be electrically connected to the response transducer. In addition, when performing non-zero comparison, a comparison reference voltage less than the zero-crossing voltage value can also be adopted, to which the embodiments of the present application are not limited. In addition, those skilled in the art can adopt a comparison reference voltage according to actual needs, for example, adopt a comparison reference voltage less than the zero-crossing voltage value, and for another example, adopt a comparison reference voltage greater than the zero-crossing voltage value. To this, the embodiments of the present application are not limited here.

[0163] Type (2): e.g. Figure 1 As shown, the comparator component 60 may include a second comparator 62 and a third comparator 63; the second comparator 62 is electrically connected to the flight time measurement unit 50, the pulse generation unit 20, the transducer component 30, and the reference voltage generation unit 70, and the reference voltage generation unit 70 is used to provide the second comparator 62 with a comparison reference voltage equal to the zero-crossing voltage value of the compared response voltage wave group, so that the second comparator 62 performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse; the third comparator 63 is electrically connected to the transducer component 30, the acoustic wave feature detection unit 40, and the reference voltage generation unit 70, respectively, and the reference voltage generation unit 70 is used to provide the third comparator 63 with a comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, so that the third comparator 63 performs a non-zero comparison on the response voltage wave group and outputs a non-zero comparison pulse.

[0164] Since the second comparator 62 is electrically connected to the pulse generating unit 20, the initial pulse group generated by the pulse generating unit 20 can be transmitted to the second comparator 62, and then transmitted to the flight time measuring unit 50 through the second comparator 62, so that the flight time measuring unit 50 can determine the start time of the acoustic wave flight. Since the second comparator 62 is electrically connected to the transducer assembly 30, and the reference voltage generating unit 70 provides the second comparator 62 with a comparison reference voltage equal to the zero-crossing voltage value of the compared response voltage wave group, the second comparator 62 performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse. Since the third comparator 63 is electrically connected to the transducer assembly 30, the acoustic wave characteristic detection unit 40, and the reference voltage generating unit 70, respectively, the control module 10 can control the reference voltage generating unit 70 to provide the third comparator 63 with a comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, so that the voltage at the comparison reference end of the third comparator 63 is a voltage greater than the zero-crossing voltage value of the compared response wave, so that the third comparator 63 performs a non-zero comparison on the response voltage wave group and outputs a non-zero comparison pulse. That is, by setting the second comparator 62 and the third comparator 63, the second comparator 62 has a zero-crossing comparison function, and the third comparator 63 has a non-zero comparison function, so that the control module 10 only needs to control the reference voltage generating unit 70 to provide the corresponding comparison reference voltage to the second comparator 62 and the third comparator 63 respectively, and remain unchanged during the flyby measurement of a sound wave group, and the design and control of the control module 10 are relatively simple, which can simplify the control logic and improve the control efficiency.

[0165] It should be noted that both the second comparator 62 and the third comparator 63 may be electrically connected to the response transducer.

[0166] It should also be noted that, in the embodiment of the present application, the comparison reference terminal of the second comparator 62 is electrically connected to the reference voltage generating unit 70. The specific reasons for setting such a connection are as follows: Figure 2As shown, since one end of the transducer assembly 30 is usually connected to the ground of the measuring device, the response voltage wave group output by the response transducer is: a voltage wave group that oscillates symmetrically with respect to the ground, that is, with respect to the amplitude of 0V voltage, and the amplitudes of its peak and trough are +Vp and -Vp respectively. Each response voltage wave in the response voltage wave group is in the negative voltage interval for 50% of the time. Therefore, the zero-crossing voltage value Vo of the response transducer is 0V. For a typical ultrasonic water meter system, its working voltage Vcc is typically 3.3V, and the peak voltage of the response voltage wave group of its transducer assembly 30 is usually 0.4V to 0.6V. In order to facilitate subsequent detection and processing and make the circuit implementation simple, the response voltage wave group of the response transducer can be coupled to the subsequent circuit through a coupling capacitor, and the response voltage wave group passing through the coupling capacitor is shifted and raised to above 0V by the coupling capacitor, such as shifting and raising 1 / 3Vcc, so that the response voltage wave group output by the coupling capacitor is in the positive voltage value interval above 0V all the time, so the zero-crossing voltage value Vo output by the coupling capacitor is Vcc / m, such as Vo=Vcc / 3. For this reason, the comparison reference end of the second comparator 62 is electrically connected to the reference voltage generating unit 70, so that the reference voltage generating unit 70 can generate a suitable voltage value to the first comparator 61. Among them, the voltage value generated by the reference voltage generating unit 70 to the second comparator 62 is less than the voltage value generated by the reference voltage generating unit 70 to the third comparator 63.

[0167] In addition, in the embodiment of the present application, the acoustic wave feature detection unit 40 can have different forms, and the acoustic wave feature detection unit 40 can be connected to different types of comparator components 60. Specifically, the following types are used as examples for description:

[0168] Mode (1): The acoustic wave feature detection unit 40 has a peak amplitude detection function, and the acoustic wave feature detection unit 40 is connected to the first comparator 61, wherein the peak amplitude attenuation detection function can be completed by the control module 10. Specifically, Figure 8As shown, the acoustic wave characteristic detection unit 40 may include a first peak detector 401, a first analog-to-digital converter 402, and a first register 403, a second register 404, and a third register 405. The first peak detector 401 is electrically connected to the transducer assembly 30 and the first analog-to-digital converter 402, respectively, the first register 403 is electrically connected to the second register 404, the second register 404 is electrically connected to the third register 405, the first register 403 is electrically connected to the first comparator 61, and the first analog-to-digital converter 402 is electrically connected to the control module 10; the first peak detector 401 is used to detect the peak amplitude of the response voltage wave in each cycle of the response voltage wave group transmitted from the transducer assembly 30, and the control module 10 is used to read the peak amplitude of the response voltage wave from the first analog-to-digital converter 402, and based on The peak amplitude of the read response voltage wave determines whether the peak amplitude of the response voltage wave is attenuated; the first register 403 is used to receive the comparison pulse output from the first comparator 61, and the first register 403 and the second register 404 are used to perform a two-level clock synchronization register delay on the comparison pulse to stabilize the comparator pulse transmitted to the third register 405. The third register 405 is used to generate a high-level pulse when the received comparator pulse signal changes from a high level to a low level to indicate that the first analog-to-digital converter 402 has completed the conversion, so that the control module 10 can read data from the first analog-to-digital converter 402.

[0169] After the control module 10 reads the data from the first analog-to-digital converter 402 , it is equivalent to that the control module 10 obtains the data detected by the acoustic wave feature detection unit 40 for the peak amplitude of the response voltage wave.

[0170] It should be noted that the third register 405 can be electrically connected to an AND gate with an inversion at the same end, so that the third register 405 and the AND gate with an inversion generate a high-level pulse of one clock cycle when receiving a comparator pulse signal from a high level to a low level; of course, the third register 405 can also be electrically connected to an inverter and an AND gate, so that the third register 405 generates a high-level pulse of one clock cycle when receiving a comparator pulse signal from a high level to a low level. This embodiment of the present application is not limited here.

[0171] It should also be noted that one or more registers can be inserted between the first register 403 and the second register 404 to further increase the delay, but the essence of this part of the circuit is not changed, and those skilled in the art can flexibly set it according to the needs of the actual device. In this regard, the embodiments of the present application are not limited here.

[0172] In addition, when only the first register 403, the second register 404 and the third register 405 are included, at this time, the third register 405 receives the comparator pulse signal transmitted by the second register 404 and changes from high level to low level to generate a high level pulse of a single clock cycle; one or more registers can be inserted between the output end of the third register 405 and the input end connected to the gate, which can further increase the number of cycles of the high level pulse width, but does not change the essence of this part of the circuit, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiment of the present application is not limited here.

[0173] It should also be noted that the first peak detector 401 may be electrically connected to the response transducer.

[0174] Mode (2): The acoustic wave feature detection unit 40 has the functions of peak amplitude detection and peak attenuation detection, and the acoustic wave feature detection unit 40 is connected to the first comparator 61. Specifically, Fig. 9As shown, the acoustic wave feature detection unit 40 may include a second peak detector 411, a third peak detector 412, a first hysteresis comparator 413, a second analog-to-digital converter 414, a fourth register 415, a fifth register 416, a sixth register 417 and a seventh register 418; the second peak detector 411 and the third peak detector 412 are both electrically connected to the transducer assembly 30, and the second peak detector 411 and the third peak detector 412 are both electrically connected to the first hysteresis comparator 413 and the second analog-to-digital converter 414. converter 414; the fourth register 415 is electrically connected to the fifth register 416, the fifth register 416 is electrically connected to the sixth register 417, the fourth register 415 is electrically connected to the first comparator 61, and the second analog-to-digital converter 414 is electrically connected to the control module 10; the second peak detector 411 is used to continuously detect and record the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group transmitted from the transducer assembly 30, and transmit the maximum value of the peak amplitude of the response voltage wave detected and recorded to the first hysteresis comparator 413, the third The peak detector 412 is used to detect and record the current peak amplitude of the response voltage wave according to the period of the response voltage wave, and transmit the detected and recorded current peak amplitude of the response voltage wave to the first hysteresis comparator 413. The first hysteresis comparator 413 is used to compare the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector 411 and the current peak amplitude of the response voltage wave transmitted by the third peak detector 412 to determine whether the peak amplitude of the response voltage wave group is attenuated, and the first hysteresis comparator 413 compares the comparison result. The seventh register 418 is transmitted to the seventh register 418, which is electrically connected to the control module 10 and the flight time measurement unit 50. When the peak amplitude of the response voltage wave is attenuated, the seventh register 418 sends a peak amplitude attenuation flag signal to the flight time measurement unit 50 to stop the current wave group measurement by the flight time measurement unit 50, and the seventh register 418 sends a peak amplitude attenuation interrupt signal to the control module 10 to enable the control module 10 to read the data measured by the flight time measurement unit 50 from the flight time measurement unit 50;The fourth register 415 is used to receive the comparator pulse signal transmitted from the first comparator 61, and the fourth register 415 and the fifth register 416 are used to perform two-stage clock synchronization register delay on the comparator pulse signal, so that the clock sampling of the comparator pulse signal transmitted to the sixth register 417 is stable, the sixth register 417 is electrically connected to the seventh register 418, the sixth register 417 is used to generate a high level pulse when the comparator pulse signal transmitted by the fifth register 416 is received and changes from a high level to a low level, so as to instruct the seventh register 418 to collect the comparison result output by the first hysteresis comparator 413 from the first hysteresis comparator 413, and the sixth register 417 is also used to transmit the pulse signal output by the comparator after register delay to the third peak detector 412, so as to be used as a reset signal of the third peak detector 412 to meet the timing requirements required for its correct operation. ;

[0175] The control module 10 is electrically connected to the second analog-to-digital converter 414, and the control module 10 can read the result of whether the peak amplitude of the response voltage wave is attenuated by the acoustic wave feature detection unit 40 from the second analog-to-digital converter 414, which is equivalent to the control module 10 obtaining the data of the peak amplitude detection of the response voltage wave by the acoustic wave feature detection unit 40. The second peak detector 411 and the third peak detector 412 can both be electrically connected to the response transducer.

[0176] In addition, the first hysteresis comparator 413 may be provided with a first hysteresis comparison threshold value. After the first hysteresis comparator 413 receives the data from the second peak detector 411 and the third peak detector 412, the first hysteresis comparator 413 will receive the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector 411, and receive the current peak amplitude of the response voltage wave recorded according to the period detection of the response voltage wave. If the difference between the maximum value of the peak amplitude of the response voltage wave and the current peak amplitude is greater than the first hysteresis comparison threshold value, the first hysteresis comparator 413 determines that the peak amplitude of the response voltage wave group has been attenuated; if the difference between the maximum value of the peak amplitude of the response voltage wave and the current peak amplitude is less than the first hysteresis comparison threshold value, the first hysteresis comparator 413 determines that the peak amplitude of the response voltage wave group has not been attenuated.

[0177] For example, the first hysteresis comparison threshold is 20, the maximum value of the peak amplitude is 100, and the current peak amplitude is 70. If the difference between the two is greater than 20, it means that the peak amplitude of the response voltage wave group has attenuated. Otherwise, it means that the peak amplitude of the response voltage wave group has not attenuated.

[0178] In addition, in the embodiment of the present application, the fifth register 416 and the sixth register 417 can be electrically connected to an AND gate with an inverted end, so that the circuit formed by the fifth register 416 and the sixth register 417 and the AND gate with an inverted end generates a high-level pulse of one clock cycle after receiving the comparator pulse signal from the high level to the low level; in addition, the sixth register 417 can be electrically connected to the AND gate, so that the sixth register 417 and the circuit formed by the AND gate provide the third peak detector 412 with the reset signal timing required for its correct operation.

[0179] It should be noted that one or more registers can be inserted between the fourth register 415 and the fifth register 416 to further increase the delay, but the essence of this part of the circuit is not changed, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiments of the present application are not limited here.

[0180] In addition, when only the fourth register 415, the fifth register 416 and the sixth register 417 are included, at this time, the sixth register 417 receives the comparator pulse signal transmitted by the fifth register 416 and changes from high level to low level to generate a high level pulse of a single clock cycle; one or more registers can be inserted between the output end of the sixth register 417 and the input end connected to the gate, which can further increase the number of cycles of the high level pulse width, but does not change the essence of this part of the circuit, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiment of the present application is not limited here.

[0181] Mode (3): The acoustic wave feature detection unit 40 has the function of peak amplitude detection, and the acoustic wave feature detection unit 40 is electrically connected to the second comparator 62 or the third comparator 63, and the function of peak amplitude attenuation detection is completed by the control module 10. Specifically, Figure 8As shown, the acoustic wave characteristic detection unit 40 may include a first peak detector 401, a first analog-to-digital converter 402, a first register 403, a second register 404, and a third register 405; the first peak detector 401 is electrically connected to the transducer assembly 30 and the first analog-to-digital converter 402, respectively, the first register 403 is electrically connected to the second register 404, the second register 404 is electrically connected to the third register 405, the first register 403 is electrically connected to the second comparator 62 or the third comparator 63, and the first analog-to-digital converter 402 is electrically connected to the control module 10; the first peak detector 401 is used to detect the peak amplitude of the response voltage wave in each cycle of the response voltage wave group transmitted from the transducer assembly 30, and the control module 10 ... The module 10 is used to read the peak amplitude of the response voltage wave from the first analog-to-digital converter 402, and determine whether the peak amplitude of the response voltage wave is attenuated based on the read peak amplitude of the response voltage wave; the first register 403 is used to receive the comparison pulse transmitted from the second comparator 62 or the third comparator 63, and the first register 403 and the second register 404 are used to delay the comparison pulse by two-level clock synchronization registers, so that the comparator pulse transmitted to the third register 405 is stable, and the third register 405 is used to generate a high-level pulse when the comparator pulse signal is received from the high level to the low level, so as to indicate that the first analog-to-digital converter 402 has completed the conversion, so that the control module 10 can read data from the first analog-to-digital converter 402. Among them, the second comparator 62 has a zero-crossing comparison function, and the third comparator 63 has a non-zero comparison function. In addition, after the control module 10 reads the data from the first analog-to-digital converter 402, it is equivalent to the control module 10 obtaining the data detected by the acoustic wave feature detection unit 40 for the peak amplitude of the response voltage wave.

[0182] It should be noted that one or more registers can be inserted between the first register 403 and the second register 404 to further increase the delay, but the essence of this part of the circuit is not changed, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiments of the present application are not limited here.

[0183] In addition, when only the first register 403, the second register 404 and the third register 405 are included, at this time, the third register 405 receives the comparator pulse signal transmitted by the second register 404 and changes from high level to low level to generate a high level pulse of a single clock cycle; one or more registers can be inserted between the output end of the third register 405 and the input end connected to the gate, which can further increase the number of cycles of the high level pulse width, but does not change the essence of this part of the circuit, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiment of the present application is not limited here.

[0184] Mode (4): The acoustic wave feature detection unit 40 has the functions of peak amplitude detection and peak attenuation detection, and the acoustic wave feature detection unit 40 is electrically connected to the second comparator 62 or the third comparator 63. Specifically, Fig. 9As shown, the acoustic wave feature detection unit 40 may include a second peak detector 411, a third peak detector 412, a first hysteresis comparator 413, a second analog-to-digital converter 414, a fourth register 415, a fifth register 416, a sixth register 417 and a seventh register 418; the second peak detector 411 and the third peak detector 412 are both electrically connected to the transducer assembly 30, and the second peak detector 411 and the third peak detector 412 are both electrically connected to the first hysteresis comparator 413 and the second analog-to-digital converter The fourth register 415 is electrically connected to the fifth register 416, the fifth register 416 is electrically connected to the sixth register 417, the fourth register 415 is electrically connected to the second comparator 62 or the third comparator 63, and the second analog-to-digital converter 414 is electrically connected to the control module 10; the second peak detector 411 is used to continuously detect and record the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group transmitted from the transducer assembly 30, and transmit the maximum value of the peak amplitude of the response voltage wave detected and recorded to the first hysteresis comparator 41 3. The third peak detector 412 is used to detect and record the current peak amplitude of the response voltage wave according to the period of the response voltage wave, and transmit the detected and recorded current peak amplitude of the response voltage wave to the first hysteresis comparator 413. The first hysteresis comparator 413 is used to compare the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector 411 and the current peak amplitude of the response voltage wave transmitted by the third peak detector 412 to determine whether the peak amplitude of the response voltage wave group is attenuated, and the first hysteresis comparator 413 compares the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector 411 and the current peak amplitude of the response voltage wave transmitted by the third peak detector 412 to determine whether the peak amplitude of the response voltage wave group is attenuated. The result is transmitted to the seventh register 418, which is electrically connected to the control module 10 and the flight time measurement unit 50. When the peak amplitude of the response voltage wave is attenuated, the seventh register 418 sends a peak amplitude attenuation flag signal to the flight time measurement unit 50 to stop the current wave group measurement, and the seventh register 418 sends a peak amplitude attenuation interrupt signal to the control module 10 to enable the control module 10 to read the data measured by the flight time measurement unit 50 from the flight time measurement unit 50;The fourth register 415 is used to receive the comparator pulse signal transmitted from the second comparator 62 or the third comparator 63, and the fourth register 415 and the fifth register 416 are used to perform two-stage clock synchronization register delay on the comparator pulse signal, so that the clock sampling of the comparator pulse signal transmitted to the sixth register 417 is stable, the fifth register 416 is electrically connected to the sixth register 417, and the sixth register 417 is used to generate a high level pulse after receiving the comparison pulse signal transmitted by the fifth register 416 from the high level to the low level, so as to instruct the seventh register 418 to collect and hold the comparison result output by the first hysteresis comparator 413 from the first hysteresis comparator 413, and the sixth register 417 is also used to transmit the pulse signal output by the comparator after the register delay to the third peak detector 412, so as to be used as the reset signal of the third peak detector 412 to meet the timing requirements required for its correct operation. ;

[0185] The control module 10 is electrically connected to the second analog-to-digital converter 414, and the control module 10 can read the result of whether the peak amplitude of the response voltage wave is attenuated by the acoustic wave characteristic detection unit 40 from the second analog-to-digital converter 414. In addition, the control module 10 reads the data measured by the flight time measurement unit 50 from the flight time measurement unit 50, that is, the control module 10 obtains the flight time, and the control module 10 can perform corresponding processing based on the flight time, for example, the control module 10 performs distance measurement based on the flight time, and for another example, the control module 10 calculates parameters such as the flow rate of the fluid based on the flight time.

[0186] It should be noted that one or more registers can be inserted between the fourth register 415 and the fifth register 416 to further increase the delay, but the essence of this part of the circuit is not changed, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiments of the present application are not limited here.

[0187] In addition, when only the fourth register 415, the fifth register 416 and the sixth register 417 are included, at this time, the sixth register 417 generates a high-level pulse of a single clock cycle when receiving the comparator pulse signal from high level to low level; one or more registers can be inserted between the output end of the sixth register 417 and the input end connected to the gate, which can further increase the number of cycles of the high-level pulse width, but does not change the essence of this part of the circuit, and professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiment of the present application is not limited here.

[0188] In addition, the first hysteresis comparator 413 may be provided with a first hysteresis comparison threshold. After the first hysteresis comparator 413 receives the data from the second peak detector 411 and the third peak detector 412, the first hysteresis comparator 413 will receive the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector 411, and receive the current peak amplitude of the response voltage wave recorded according to the period detection of the response voltage wave. If the difference between the maximum value of the peak amplitude of the response voltage wave group and the current peak amplitude is greater than the comparison threshold of the first hysteresis comparator, the first hysteresis comparator 413 determines that the peak amplitude of the response voltage wave group has been attenuated; if the difference between the maximum value of the peak amplitude of the response voltage wave group and the current peak amplitude is less than the comparison threshold of the first hysteresis comparator, the first hysteresis comparator 413 determines that the peak amplitude of the response voltage wave group has not been attenuated.

[0189] For example, the first hysteresis comparison threshold is 20, the maximum value of the peak amplitude is 100, and the current peak amplitude is 70. If the difference between the two is greater than 20, it means that the peak amplitude of the response voltage wave group has attenuated. Otherwise, it means that the peak amplitude of the response voltage wave group has not attenuated.

[0190] Mode (5): The acoustic wave feature detection unit 40 has a waveform intercept attenuation detection function, the acoustic wave feature detection unit 40 is electrically connected to the flight time measurement unit 50, and the acoustic wave feature detection unit 40 is electrically connected to the second comparator 62 and the third comparator 63, or the acoustic wave feature detection unit 40 is only electrically connected to the third comparator 63. Specifically, Fig.14As shown, the acoustic wave feature detection unit 40 may include a first waveform intercept detection unit 421, a sub-comparator 422, a gate 423, an eighth register 424, a second hysteresis comparator 425, a ninth register 426, a tenth register 427, an eleventh register 428, a twelfth register 429, a thirteenth register 430 and a first control unit 431; the first waveform intercept detection unit 421 is electrically connected to the first control unit 431, the third comparator 63, the sub-comparator 422, the gate 423 and the second hysteresis comparator 425, respectively, and the first control unit 431 is electrically connected to the control module 10, the first The waveform intercept detection unit 421, the second hysteresis comparator 425, the eighth register 424 and the ninth register 426 are electrically connected, the gate 423 is electrically connected to the first waveform intercept detection unit 421, the sub-comparator 422, and the eighth register 424, the eighth register 424 is electrically connected to the second hysteresis comparator 425, the second hysteresis comparator 425 is electrically connected to the ninth register 426, the sub-comparator 422, the eighth register 424, and the gate 423, the ninth register 426 is electrically connected to the first control unit 431 and the flight time measurement unit 50, the second hysteresis comparator 425 is electrically connected to the first control unit 431, and the flight time measurement unit 50. The unit 431 is electrically connected, the second hysteresis comparator 425 is used to compare the waveform intercept value of the current response voltage wave transmitted from the first waveform intercept detection unit 421 and the maximum intercept value of the response voltage wave group recorded and maintained by the eighth register 424, and send the comparison result to the first control unit 431, the first control unit 431 sends the comparison result to the control module 10, when the waveform intercept of the response voltage wave group appears to be attenuated beyond the attenuation threshold, the ninth register 426 sends a waveform intercept attenuation flag signal to the flight time measurement unit 50, so that the flight time measurement unit 50 stops the current wave group measurement, and the ninth register The device 426 sends a waveform intercept attenuation signal to the first control unit 431, and the first control unit 431 sends a waveform intercept attenuation interrupt signal to the control module 10, so that the control module 10 reads the data measured by the flight time measurement unit 50 from the flight time measurement unit 50; the eleventh register 428 is electrically connected to the second comparator 62 or the third comparator 63, the eleventh register 428 is electrically connected to the twelfth register 429, the twelfth register 429 is electrically connected to the thirteenth register 430, the thirteenth register 430 is electrically connected to the tenth register 427, and the tenth register 427 is electrically connected to the ninth register 426;The eleventh register 428 is used to receive the comparator pulse signal transmitted from the second comparator 62 or the third comparator 63, and the eleventh register 428 and the twelfth register 429 are used to perform two-stage clock synchronization register delay on the comparator pulse signal so as to stabilize the clock sampling of the comparator pulse signal transmitted to the thirteenth register 430. The thirteenth register 430 is electrically connected to the eighth register 424. The thirteenth register 430 is used to generate a high level pulse when receiving the comparator pulse signal transmitted by the twelfth register 429 from high level to low level, so as to instruct the eighth register 424 to update the saved data, otherwise the eighth register 424 maintains the data transmitted to the eighth register 424. The high level pulse generated by the thirteenth register 430 is delayed by one clock cycle by the tenth register 427 to instruct the ninth register 426 to collect the comparison output result of the second hysteresis comparator 425, and transmit the collected result to the first control unit 431, and the thirteenth register 430 and the circuit formed by the AND gate provide the first waveform intercept detection unit 421 with the reset signal timing required for correct operation.

[0191] Wherein, the second hysteresis comparator 425 may have a hysteresis comparison function, and the second hysteresis comparator 425 may be provided with a second hysteresis comparison threshold, which may be configured by the control module 10. If the difference between the maximum intercept value of the response voltage wave group recorded and maintained by the eighth register 424 and the current intercept value of the current response voltage wave transmitted by the waveform intercept detection unit is greater than the second hysteresis comparison threshold of the second hysteresis comparator, the second hysteresis comparator 425 determines that the waveform intercept of the response voltage wave group has been attenuated; otherwise, the second hysteresis comparator 425 determines that the peak amplitude of the response voltage wave group has not been attenuated. For example, if the second hysteresis comparison threshold is 20, the maximum intercept value of the response voltage wave group is 100, and the intercept value of the current response voltage wave is 60, then the difference between the two, 40, is greater than 20, indicating that the waveform intercept of the response voltage wave group has been attenuated, otherwise, it indicates that the waveform intercept of the response voltage wave group has not been attenuated.

[0192] It should be noted that the thirteenth register 430 and the tenth register 427 can be electrically connected through an AND gate with an inverted end. Of course, the thirteenth register 430 and the tenth register 427 can also be electrically connected through an inverter and an AND gate, which is not limited in this embodiment of the present application.

[0193] In addition, in the embodiment of the present application, the thirteenth register 430 can be electrically connected to an AND gate with an inversion at one end, so that the circuit formed by the thirteenth register 430 and the AND gate with an inversion at one end is used to generate a high-level pulse of one clock cycle when the comparator pulse signal is received and changes from a high level to a low level. Of course, the thirteenth register 430 can also be electrically connected to an inverter and an AND gate, so that the thirteenth register 430 generates a high-level pulse of one clock cycle when the comparator pulse signal is received and changes from a high level to a low level.

[0194] In addition, the thirteenth register 430 can be electrically connected to an AND gate, so that the thirteenth register 430 and the circuit formed by the AND gate provide the first waveform intercept detection unit 421 with a reset signal timing required for correct operation.

[0195] It should be noted that one or more registers can be inserted between the eleventh register 428 and the twelfth register 429 to further increase the delay, but the essence of this part of the circuit is not changed, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiments of the present application are not limited here.

[0196] In addition, when only the eleventh register 428, the twelfth register 429 and the thirteenth register 430 are included, at this time, the thirteenth register 430 receives the comparator pulse signal transmitted by the twelfth register 429 and changes from a high level to a low level to generate a high level pulse of a single clock cycle; one or more registers can be inserted between the output end of the thirteenth register 430 and the input end connected to the gate, which can further increase the number of cycles of the high level pulse width, but does not change the essence of this part of the circuit, and the professional and technical personnel can flexibly set it according to the needs of the actual device. In this regard, the embodiment of the present application is not limited here.

[0197] Mode (6): The acoustic wave feature detection unit 40 has a waveform intercept detection function, and the acoustic wave feature detection unit 40 is electrically connected to the third comparator 63, and the waveform intercept attenuation detection function is completed by the control module 10. Specifically, Fig.15As shown, the acoustic wave feature detection unit 40 includes a second control unit 441 and a second waveform intercept detection unit 442; the second control unit 441 is electrically connected to the second waveform intercept detection unit 442, and the second control unit 441 is also electrically connected to the control module 10 and the third comparator 63 respectively; the second control unit 441 is used to receive the comparator pulse signal transmitted from the third comparator 63, and convert the comparator pulse signal into a conversion pulse signal that can be identified and detected by the second waveform intercept detection unit 442, and send it to the second waveform intercept detection unit 442, the second waveform intercept detection unit 442 is used to detect the rising edge and the falling edge of the conversion pulse signal, and send the detection values ​​of the detected rising edge and the falling edge to the second control unit 441, the control module 10 periodically and continuously reads the detection values ​​of the rising edge and the falling edge from the second control unit 441, and determines the waveform intercept value of each response voltage wave based on the detection values ​​of the rising edge and the falling edge to determine whether the waveform intercept of the response wave group is attenuated.

[0198] Among them, the comparator pulse signal of the third comparator 63 can be transmitted to the second control unit 441, and the second control unit 441 can convert the comparator pulse signal into a conversion pulse signal recognizable by the second waveform intercept detection unit 442. Specifically, the second control unit 441 can convert each comparator pulse signal, so that each comparator pulse signal is converted into a conversion pulse signal. After that, the second control unit 441 can send the conversion pulse signal to the second waveform intercept detection unit 442, and the second waveform intercept detection unit 442 can detect the rising edge and falling edge of each conversion pulse signal, and send the detection structure to the second control unit 441, and the second control unit 441 can receive the detection values ​​of the rising edge and falling edge of the conversion pulse signal. The second control unit 441 is electrically connected to the control module 10, so that the control module 10 can periodically and continuously read the detection values ​​of the rising edge and the falling edge through the second control unit 441, and determine the waveform intercept of each response voltage wave based on the detection values ​​of the rising edge and the falling edge, and then the control module 10 determines whether the waveform intercept of the response wave group is attenuated by continuously determining the waveform intercept value of the response wave of the response voltage wave group. Among them, during the period when the response transducer generates a voltage wave group, the second control unit 441 can continuously receive the pulse signal output by the third comparator 63, and the second control unit 441 can send the control module 10 an interrupt signal indicating that the waveform intercept detection is completed at the end of each pulse signal, so that the control module 10 can continuously read the detection values ​​of the rising edge and the falling edge from the second control unit 441 according to the pulse period, and continuously determine the waveform intercept value and whether the waveform intercept is attenuated.

[0199] For example, after the control module 10 currently receives the rising edge and falling edge of the conversion pulse signal, the waveform intercept value determined is 3, and after the control module 10 receives the rising edge and falling edge of a conversion pulse signal before the current time, the waveform intercept value determined is 5, then the control module 10 can determine that the waveform intercept of the response voltage wave begins to decay.

[0200] In addition, in some embodiments, Figure 1 As shown, the device for measuring the acoustic wave flight time may also include a pulse counting unit 80; the pulse counting unit 80 is electrically connected to the control module 10 and the comparator component 60 respectively, and the pulse counting unit 80 is used to count the number of pulses transmitted to the pulse counting unit 80, and transmit the counted number of pulses to the control module 10.

[0201] Among them, by setting the pulse counting unit 80, the pulse counting unit 80 can transmit the counted number of pulses to the control module 10, so that the control module 10 can determine whether the reference comparison voltage provided by the reference voltage generating unit 70 to the comparator component 60 is appropriate, whether the current excitation response wave group test overflows, whether the setting of the first hysteresis comparison threshold of the first hysteresis comparator 413 is appropriate, and whether the setting of the second hysteresis comparison threshold of the second hysteresis comparator 425 is appropriate based on the number of pulses transmitted by the pulse counting unit 80.

[0202] In addition, in some embodiments, Figure 1 As shown, the device for measuring the acoustic wave flight time may also include an analog gate 130; the analog gate 130 is electrically connected to the pulse generating unit 20 and the transducer assembly 30, and the analog gate 130 is electrically connected to the comparator assembly 60, and the analog gate 130 is switched on so that the initial pulse group emitted by the pulse generating unit 20 is transmitted to the comparator assembly 60, or the response voltage wave group generated by the transducer assembly 30 is transmitted to the comparator assembly 60.

[0203] The analog gate 130 can be configured to switch on and off, so that when the initial pulse group emitted by the pulse generating unit 20 is transmitted to the analog gate 130, the analog gate 130 can be configured to be turned on, so that the initial pulse group passes through the analog gate 130, and the initial pulse group is transmitted to the flight time measurement unit 50, so that the flight time measurement unit 50 determines the start time of the acoustic wave flight. Once the initial pulse group is transmitted, the analog gate 130 can be configured to disconnect the path for transmitting the initial pulse group, so that the initial pulse group cannot pass through the analog gate 130, and thus cannot be continuously transmitted to the flight time measurement unit 50. And the analog gate 130 can be configured to conduct the path of the response voltage wave group generated by the transducer assembly 30, so that the response voltage wave group can be continuously transmitted to the comparator assembly 60.

[0204] It should be noted that the analog gate 130 may be electrically connected to the response transducer.

[0205] It should also be noted that, based on the functional role of the analog gate 130 in the embodiment of the present application, a circuit that uses basic circuits such as analog switches to implement the same function of the analog gate 130 can also be derived, and those skilled in the art can flexibly set it according to the needs of the actual device and the feasibility of various basic circuits. This patent application does not limit this.

[0206] In addition, in some embodiments, Figure 5 and Fig.16 As shown, the measuring device for acoustic wave flight time may further include a first coupling capacitor 140 and a second coupling capacitor 150, and the transducer assembly 30 includes a first transducer 31 and a second transducer 32. The first coupling capacitor 140 is electrically connected to the first transducer 31, and the second coupling capacitor 150 is electrically connected to the second transducer 32; wherein, when the first transducer 31 is used as a response transducer, the first coupling capacitor 140 is used to couple the response voltage of the first transducer 31 to the comparator assembly 60 and / or the acoustic wave characteristic detection unit 40; when the second transducer 32 is used as a response transducer, the second coupling capacitor 150 is used to couple the response voltage of the second transducer 32 to the comparator assembly 60 and / or the acoustic wave characteristic detection unit 40. That is, by setting the first coupling capacitor 140 and the second coupling capacitor 150, when the first transducer 31 is used as the response transducer, the first coupling capacitor 140 can be used, and when the second transducer 32 is used as the response transducer, the second coupling capacitor 150 can be used, so that the internal circuit design of the acoustic wave flight time measuring device is relatively simple. In addition, by setting the first transducer 31 and the second transducer 32, the distance measurement can be performed by the acoustic wave flight time measuring device, and when the acoustic wave flight time measuring device includes the measuring tube 110, the flow velocity, flow rate and other parameters of the fluid in the measuring tube 110 can also be measured.

[0207] In addition, in some embodiments, Figures 19 to 21 As shown, the measuring device for the acoustic wave flight time further includes a third coupling capacitor 200 and a third transducer 33. The third coupling capacitor 200 is electrically connected to the third transducer 33. When the third transducer 33 is used as a response transducer, the third coupling capacitor 200 is used to couple the response voltage of the third transducer 33 to the comparator component 60 and the acoustic wave characteristic detection unit 40, or to the comparator component 60. In addition, by setting the third transducer 33, distance measurement can be performed by the acoustic wave flight time measuring device.

[0208] In addition, in some embodiments, Figure 1As shown, the measuring device of the acoustic wave flight time can also include a bus interface unit 160 and a timer unit 170; the bus interface unit 160 is electrically connected to the control module 10, the pulse generating unit 20, the flight time measuring unit 50, the acoustic wave characteristic detecting unit 40, and the timer unit 170 respectively. Through such a setting, the control module 10 can transmit a control signal to the pulse generating unit 20, the flight time measuring unit 50, the acoustic wave characteristic detecting unit 40, and the timer unit 170 through the bus interface unit 160, or the control module 10 obtains data from these components through the bus interface unit 160 and performs corresponding control. Among them, the timer unit 170 is electrically connected to the control module 10 through the bus interface unit 160, and the timer unit 170 can have a watchdog timer interrupt function.

[0209] It should be noted that the bus interface unit 160 may also be electrically connected to the reference voltage generating unit 70 , so that the control module 10 may control the reference voltage generating unit 70 through the bus interface unit 160 .

[0210] In addition, in some embodiments, Figure 1 As shown, the measuring device of the acoustic wave flight time may further include an interrupt control unit 180; the interrupt control unit 180 is electrically connected to the acoustic wave characteristic detection unit 40, the pulse counting unit 80, the flight time measurement unit 50, the pulse generating unit 20 and the control module 10 respectively; the interrupt control unit 180 is used to receive and process the interrupt signal generated by at least one of the acoustic wave characteristic detection unit 40, the pulse counting unit 80, the flight time measurement unit 50 and the pulse generating unit 20, and then convert it into an interrupt signal of a unified mode and transmit it to the control module 10, so that the control module 10 performs corresponding processing. That is, by setting the interrupt control unit 180, it is convenient for the control module 10 to receive the interrupt signal of the unified mode, so that the control module 10 performs corresponding processing.

[0211] In addition, in the embodiments of the present application, Figure 1 As shown, the device for measuring the acoustic wave transit time may further include other functional units 190. The other functional units 190 may be electrically connected to the control module 10.

[0212] In the embodiment of the present application, by setting up an acoustic wave characteristic detection unit 40 and a control module 10, it is possible to determine whether the peak amplitude or waveform intercept is attenuated through the acoustic wave characteristic detection unit 40 or the control module 10. Once it is determined that the peak amplitude or waveform intercept begins to attenuate, the flight time measurement unit 50 determines the stop time of the acoustic wave flight. This stop time is an accurate time, and the start time of the acoustic wave flight is accurate. Therefore, based on the accurate start time and the accurate stop time, the flight time of the acoustic wave flight can be accurately determined, and then the corresponding other parameters can be more accurately determined according to the flight time of the acoustic wave flight.

[0213] The present application embodiment provides a method for measuring the acoustic wave transit time, which is applied to the acoustic wave transit time measuring device in any of the above embodiments, such as Fig. 22 As shown, the method for measuring the acoustic wave flight time includes:

[0214] Step 101: Determine the start time of the sound wave flight.

[0215] Among them, when the flight time measurement unit receives the initial pulse group, the flight time measurement unit can use the time of receiving the initial pulse group as the starting time of the sound wave group flight. Because the initial pulse wave is a periodic rectangular wave or square wave pulse, the starting time of the sound wave flight of the sound wave excited by any period of the initial pulse group can be obtained through simple mathematical calculations. Therefore, it is equivalent to determining the starting time of the sound wave flight.

[0216] Among them, the rising edge or falling edge of the first pulse of the initial pulse group can be selected to determine the starting time of the acoustic wave group flying and the starting time of the acoustic wave flying. Of course, the rising edge or falling edge of any pulse of the initial pulse group can also be selected to determine the starting time of the acoustic wave group flying and the starting time of the acoustic wave flying. To this end, the embodiments of the present application are not limited here. In the embodiments of the present application, the rising edge of the first pulse of the initial pulse group pulse is used to illustrate the principle of determining the starting time of the acoustic wave group flying and determining the starting time of the acoustic wave flying.

[0217] Step 102: Determine the stop time of the acoustic wave flying.

[0218] Wherein, when the acoustic wave characteristic detection unit detects the attenuation of the peak amplitude or waveform intercept of the response voltage wave, an attenuation flag signal is sent to the flight time measurement unit and the control module, the flight time measurement unit stops detection, and the time point corresponding to the pulse edge of the zero-crossing comparison pulse of a certain response wave before the detection is stopped is used as the stop time of the acoustic wave flight. For example, in the process of the response voltage wave transmission, if the response voltage wave begins to decay, the time point corresponding to the pulse rising edge or falling edge of the zero-crossing comparison pulse of one or more response waves adjacent to the time of the start of decay before the start of decay can be used as the stop time of the acoustic wave flight. For simplicity, the rising edge or falling edge of the zero-crossing comparison pulse corresponding to the response voltage wave adjacent to the response voltage wave before the response voltage wave begins to decay can be selected to determine the stop time of the acoustic wave group flight. In this application, the rising edge of the zero-crossing comparison pulse corresponding to the response voltage wave is used to determine the stop time to explain the principle of the present application about determining the stop time of the acoustic wave group flight.

[0219] Step 103: Determine the flying time of the acoustic wave flying according to the starting time and the stopping time.

[0220] The flying time of the acoustic wave group is the time difference between the time when the last acoustic wave of the excited acoustic wave group arrives at the receiving transducer and the time when the first acoustic wave departs from the exciting transducer. The pulses of the initial pulse group are periodic rectangular waves or square waves, and the pulse period and the number of pulses are configured by the control module and are known quantities. After determining the starting time and the stopping time of the acoustic wave group flying, the flying time of the acoustic wave group flying can be obtained through simple mathematical operations, for example:

[0221] The flying time of the sound wave group = the stopping time of the sound wave group flying - the starting time of the sound wave group flying

[0222] Furthermore, the flight time of a sound wave in the sound wave group can be obtained as follows:

[0223] The flying time of the sound wave = the stopping time of the flying of the sound wave group - the starting time of the flying of the sound wave group - the pulse period of the initial pulse group x Number of pulses

[0224] In addition, in some implementations, the stop time includes at least two consecutive flight stop times; before determining the flight time of the sound wave group based on the start time and the stop time, the sound wave flight time measurement method may also include: detecting whether the stop time is valid, if the stop time is valid, determining the flight time of the sound wave group based on the start time and the stop time; if the stop time is invalid, re-determining the stop time until the stop time is valid.

[0225] In addition, in some implementations, before measuring the acoustic wave flight time, the pulse generator may be configured so that the initial pulse in the initial pulse group emitted is a periodic rectangular wave or a square wave. The implementation method for detecting whether the stop time is valid can be: subtracting two consecutive fly-by stop times to obtain a fly-by stop time difference; comparing the fly-by stop time difference with the emission pulse period of the pulse emitted by the pulse generator, if the difference between the fly-by stop time difference and the emission pulse period is within the preset difference range, then the two fly-by stop times are valid, if the difference between the fly-by stop time difference and the emission pulse period is outside the preset difference range, then the two fly-by stop times are invalid; or, subtracting any two adjacent fly-by stop times in at least three consecutive fly-by stop times to obtain at least two fly-by stop time differences; comparing any fly-by stop time difference with the emission pulse period of the pulse emitted by the pulse generator, if the difference between the fly-by stop time difference and the emission pulse period is within the preset difference range, then the two fly-by stop times corresponding to the fly-by stop time difference are valid, if the difference between the fly-by stop time difference and the emission pulse period is outside the preset difference range, then the two fly-by stop times corresponding to the fly-by stop time difference are invalid.

[0226] In addition, in some implementations, the flight time measurement device further includes a reference voltage generating unit, a first comparator or a third comparator, and a pulse counting unit; before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method may further include: obtaining the measurement value of the pulse output from the first comparator or the third comparator measured by the pulse counting unit within a preset time period; determining whether the measurement value is within a preset value range; if the measurement value is within the preset value range, then the non-zero comparison reference voltage of the first comparator or the third comparator is not adjusted; if the measurement value is not within the preset value range, and the measurement value is less than the minimum value of the preset value range, then the non-zero comparison reference voltage of the first comparator or the third comparator is reduced until the measurement value is within the preset value range, and if the measurement value is greater than the maximum value of the preset value range, then the non-zero comparison reference voltage of the first comparator or the third comparator is increased until the measurement value is within the preset value range. Once the measurement value is within the preset value range, it indicates that the non-zero comparison reference voltage of the first comparator or the third comparator is appropriate. In this way, the bias threshold of the first comparator or the third comparator can be adaptively adjusted according to the use of the acoustic wave flight time measurement device, without the need for manual setting based on experience, so that the flight time measurement for the acoustic wave flight is always more accurate.

[0227] The non-zero comparison reference voltage may be a comparison reference voltage greater than a zero-crossing voltage value.

[0228] In addition, in some implementations, the acoustic wave feature detection unit may include a first hysteresis comparator, the first hysteresis comparator is provided with a first hysteresis comparison threshold, and before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method may also include: determining the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group, and the peak amplitude of the attenuated first wave when the response voltage wave in the response voltage wave group initially attenuates; determining the peak amplitude attenuation difference between the maximum value of the peak amplitude of the response wave and the peak amplitude of the attenuated first wave; based on the peak amplitude attenuation difference, determining whether the first hysteresis comparison threshold of the first hysteresis comparator meets the requirements. In this way, the first hysteresis comparison threshold of the first hysteresis comparator can be adaptively adjusted according to the use of the acoustic wave flight time measurement device, without the need for manual setting based on experience, so that the flight time measurement for the acoustic wave flight is always more accurate.

[0229] In addition, in some implementations, the acoustic wave feature detection unit may include a second hysteresis comparator, the second hysteresis comparator is provided with a second hysteresis comparison threshold, and before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method may also include: determining the maximum value of the waveform intercept of the response voltage wave in the response voltage wave group, and the attenuation waveform intercept value of the attenuation first wave of the response voltage wave in the response voltage wave group when the response voltage wave is initially attenuated; determining the intercept attenuation difference between the maximum value of the waveform intercept of the response voltage wave and the attenuation waveform intercept value of the attenuation first wave; based on the intercept attenuation difference, determining whether the second hysteresis comparison threshold of the second hysteresis comparator meets the requirements. In this way, the second hysteresis comparison threshold of the second hysteresis comparator can be adaptively adjusted according to the use of the acoustic wave flight time measurement device, without the need for manual setting based on experience, so that the flight time measurement for the acoustic wave flight is always more accurate.

[0230] An embodiment of the present application provides a device, which includes the device for measuring the acoustic wave transit time in any of the above embodiments.

[0231] It should be noted that the equipment in the embodiments of the present application includes but is not limited to vehicles, ships, submarines, water meters, heat meters, gas meters, oil meters, flow meters, etc.

[0232] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0233] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A device for measuring the acoustic wave transit time, characterized in that: The acoustic wave flight time measuring device comprises: a control module, a pulse generating unit, a transducer assembly, an acoustic wave characteristic detecting unit, a flight time measuring unit and a comparator assembly; The flight time measurement unit, the acoustic wave characteristic detection unit, and the pulse generating unit are all electrically connected to the control module; the pulse generating unit is electrically connected to the transducer assembly, the comparator assembly, and the flight time measurement unit, respectively; the transducer assembly is electrically connected to the comparator assembly, the comparator assembly is electrically connected to the acoustic wave characteristic detection unit and the flight time measurement unit, the acoustic wave characteristic detection unit is electrically connected to the transducer assembly, the flight time measurement unit, and the control module, respectively; the transducer assembly is used to generate and transmit an acoustic wave group, and / or receive an acoustic wave group; The pulse generating unit is used to generate an initial pulse group, and the initial pulse group can be transmitted to the flight time measuring unit, the comparator component and the transducer component. The flight time measuring unit is used to determine the start time of the acoustic wave flight when receiving the initial pulse group. The transducer component is used to stimulate the transducer component to generate and emit an acoustic wave group when receiving the initial pulse group, and the transducer component is also used to generate a response voltage wave group when receiving the acoustic wave group, and the response voltage wave group can be transmitted to the acoustic wave characteristic detection unit and the comparator component; the acoustic wave characteristic detection unit is used to detect the peak amplitude or waveform intercept of the response voltage wave, and send the detection result to the control module, and the control module determines whether the peak amplitude or waveform intercept of the response voltage wave is attenuated; or, the acoustic wave characteristic detection unit detects the peak amplitude or waveform intercept of the response voltage wave, and determines whether the peak amplitude or waveform intercept of the response voltage wave is attenuated; When it is determined that the peak amplitude attenuation or the waveform intercept attenuation of the response voltage wave is attenuated, the flight time measurement unit stops the current wave group measurement and determines the stop time of the sound wave flight. The flight time measurement unit or the control module determines the flight time of the sound wave group according to the start time and stop time of the sound wave flight.

2. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave transit time also includes a reference voltage generating unit; The reference voltage generating unit is electrically connected to the control module and the comparator component respectively, and is used to provide a comparison reference voltage to the comparator component, wherein the comparison reference voltage is a voltage greater than or equal to a zero-crossing voltage value.

3. The device for measuring the acoustic wave transit time according to claim 2, characterized in that: The comparator assembly includes a first comparator; The first comparator is electrically connected to the reference voltage generating unit, the flight time measuring unit, the acoustic wave characteristic detecting unit, the transducer assembly, and the pulse generating unit respectively; The response voltage wave group transmitted to the first comparator can be transmitted to the flight time measurement unit. The control module controls the reference voltage generating unit to provide the first comparator with a comparison reference voltage greater than the zero-crossing voltage value, so that the first comparator performs a non-zero comparison on the response voltage wave group. When the peak value of the response voltage wave is higher than the comparison reference voltage, the first comparator outputs a non-zero comparison pulse. After one or more non-zero comparison pulses are output, the control module controls the reference voltage generating unit to provide the first comparator with a comparison reference voltage equal to the zero-crossing voltage value, so that the first comparator performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse until the measurement process ends.

4. The device for measuring the acoustic wave transit time according to claim 3, characterized in that: The acoustic wave characteristic detection unit includes a first peak detector, a first analog-to-digital converter, and a first register, a second register, and a third register; The first peak detector is electrically connected to the transducer assembly and the first analog-to-digital converter, respectively, the first register is electrically connected to the second register, the second register is electrically connected to the third register, the first register is electrically connected to the first comparator, and the first analog-to-digital converter is electrically connected to the control module; The first peak detector is used to detect the peak amplitude of the response voltage wave in each cycle of the response voltage wave group transmitted from the transducer assembly, and the control module is used to read the peak amplitude of the response voltage wave from the first analog-to-digital converter, and determine whether the peak amplitude of the response voltage wave is attenuated based on the read peak amplitude of the response voltage wave; The first register is used to receive a comparison pulse transmitted from the first comparator, and the first register and the second register are used to perform a two-level clock synchronization register delay on the comparison pulse to stabilize the comparator pulse transmitted to the third register. The third register is used to generate a high-level pulse when the received comparator pulse signal changes from a high level to a low level to indicate that the first analog-to-digital converter has completed the conversion, so that the control module can read data from the first analog-to-digital converter.

5. The device for measuring the acoustic wave transit time according to claim 3, characterized in that: The acoustic wave feature detection unit includes a second peak detector, a third peak detector, a first hysteresis comparator, a second analog-to-digital converter, a fourth register, a fifth register, a sixth register and a seventh register; The second peak detector and the third peak detector are both electrically connected to the transducer assembly, and the second peak detector and the third peak detector are both electrically connected to the first hysteresis comparator and the second analog-to-digital converter; the fourth register is electrically connected to the fifth register, the fifth register is electrically connected to the sixth register, the fourth register is electrically connected to the first comparator, and the second analog-to-digital converter is electrically connected to the control module; The second peak detector is used to continuously detect and record the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group transmitted from the transducer assembly, and transmit the maximum value of the peak amplitude of the response voltage wave detected and recorded to the first hysteresis comparator. The third peak detector is used to detect and record the current peak amplitude of the response voltage wave according to the period of the response voltage wave, and transmit the detected and recorded current peak amplitude of the response voltage wave to the first hysteresis comparator. The first hysteresis comparator is used to detect the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector and the current peak amplitude of the response voltage wave transmitted by the third peak detector. The first hysteresis comparator transmits the comparison result to the seventh register, the seventh register is electrically connected to the control module and the flight time measurement unit, and when the peak amplitude of the response voltage wave is attenuated, the seventh register sends a peak amplitude attenuation flag signal to the flight time measurement unit to make the flight time measurement unit stop the current wave group measurement, and the seventh register sends a peak amplitude attenuation interrupt signal to the control module to make the control module read the data measured by the flight time measurement unit from the flight time measurement unit; The fourth register is used to receive the comparator pulse signal transmitted from the first comparator, and the fourth register and the fifth register are used to perform a two-level clock synchronization register delay on the comparator pulse signal so that the clock sampling of the comparator pulse signal transmitted to the sixth register is stable. The sixth register is electrically connected to the seventh register. The sixth register is used to generate a high-level pulse when the comparator pulse signal transmitted by the fifth register changes from a high level to a low level, so as to instruct the seventh register to collect the comparison result output by the first hysteresis comparator from the first hysteresis comparator, and the sixth register is also used to transmit a reset signal timing to the third peak detector.

6. The device for measuring the acoustic wave transit time according to claim 2, characterized in that: The comparator component includes a second comparator and a third comparator; The second comparator is electrically connected to the flight time measurement unit, the pulse generating unit, the transducer assembly, the acoustic wave characteristic detection unit, and the reference voltage generating unit. The reference voltage generating unit is used to provide the second comparator with a comparison reference voltage equal to the zero-crossing voltage value of the compared response voltage wave group, so that the second comparator performs a zero-crossing comparison on the response voltage wave group and outputs a zero-crossing comparison pulse. The third comparator is electrically connected to the transducer assembly, the acoustic wave characteristic detection unit, and the reference voltage generating unit, respectively. The reference voltage generating unit is used to provide the third comparator with a comparison reference voltage greater than the zero-crossing voltage value of the compared response voltage wave group, so that the third comparator performs a non-zero comparison on the response voltage wave group and outputs a non-zero comparison pulse.

7. The device for measuring the acoustic wave transit time according to claim 6, characterized in that: The acoustic wave characteristic detection unit includes a first peak detector, a first analog-to-digital converter, and a first register, a second register, and a third register; The first peak detector is electrically connected to the transducer assembly and the first analog-to-digital converter, respectively, the first register is electrically connected to the second register, the second register is electrically connected to the third register, the first register is electrically connected to the second comparator or the third comparator, and the first analog-to-digital converter is electrically connected to the control module; The first peak detector is used to detect the peak amplitude of the response voltage wave in each cycle of the response voltage wave group transmitted from the transducer assembly, and the control module is used to read the peak amplitude of the response voltage wave from the first analog-to-digital converter, and determine whether the peak amplitude of the response voltage wave is attenuated based on the read peak amplitude of the response voltage wave; The first register is used to receive a comparison pulse transmitted from the second comparator or the third comparator, and the first register and the second register are used to perform a two-level clock synchronization register delay on the comparison pulse to stabilize the comparator pulse transmitted to the third register. The third register is used to generate a high-level pulse when the received comparator pulse signal changes from a high level to a low level to indicate that the first analog-to-digital converter has completed the conversion, so that the control module can read data from the first analog-to-digital converter.

8. The device for measuring the acoustic wave transit time according to claim 6, characterized in that: The acoustic wave feature detection unit includes a second peak detector, a third peak detector, a first hysteresis comparator, a second analog-to-digital converter, a fourth register, a fifth register, a sixth register and a seventh register; The second peak detector and the third peak detector are both electrically connected to the transducer assembly, and the second peak detector and the third peak detector are both electrically connected to the first hysteresis comparator and the second analog-to-digital converter; the fourth register is electrically connected to the fifth register, the fifth register is electrically connected to the sixth register, the fourth register is electrically connected to the second comparator or the third comparator, and the second analog-to-digital converter is electrically connected to the control module; The second peak detector is used to continuously detect and record the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group transmitted from the transducer assembly, and transmit the maximum value of the peak amplitude of the response voltage wave detected and recorded to the first hysteresis comparator. The third peak detector is used to detect and record the current peak amplitude of the response voltage wave according to the period of the response voltage wave, and transmit the detected and recorded current peak amplitude of the response voltage wave to the first hysteresis comparator. The first hysteresis comparator is used to detect the maximum value of the peak amplitude of the response voltage wave transmitted by the second peak detector and the current peak amplitude of the response voltage wave transmitted by the third peak detector. The first hysteresis comparator transmits the comparison result to the seventh register, the seventh register is electrically connected to the control module and the flight time measurement unit, and when the peak amplitude of the response voltage wave is attenuated, the seventh register sends a peak amplitude attenuation flag signal to the flight time measurement unit to make the flight time measurement unit stop the current wave group measurement, and the seventh register sends a peak amplitude attenuation interrupt signal to the control module to make the control module read the data measured by the flight time measurement unit from the flight time measurement unit; The fourth register is used to receive the comparator pulse signal transmitted from the second comparator or the third comparator, and the fourth register and the fifth register are used to perform a two-level clock synchronization register delay on the comparator pulse signal so that the clock sampling of the comparator pulse signal transmitted to the sixth register is stable. The sixth register is electrically connected to the seventh register. The sixth register is used to generate a high-level pulse when the comparator pulse signal transmitted by the fifth register changes from a high level to a low level, so as to instruct the seventh register to collect the comparison result output by the first hysteresis comparator from the first hysteresis comparator, and the sixth register is also used to transmit a reset signal timing to the third peak detector.

9. The device for measuring the acoustic wave transit time according to claim 6, characterized in that: The acoustic wave feature detection unit includes a first waveform intercept detection unit, a sub-comparator, a gate, an eighth register, a second hysteresis comparator, a ninth register, a tenth register, an eleventh register, a twelfth register, a thirteenth register and a first control unit; The first waveform intercept detection unit is electrically connected to the first control unit, the third comparator, the sub-comparator, the gate and the second hysteresis comparator respectively; the first control unit is electrically connected to the control module, the first waveform intercept detection unit, the second hysteresis comparator, the eighth register and the ninth register; the gate is electrically connected to the first waveform intercept detection unit, the sub-comparator and the eighth register respectively; the eighth register is electrically connected to the second hysteresis comparator; the second hysteresis comparator is electrically connected to the ninth register, the first waveform intercept detection unit, the sub-comparator and the gate respectively; the ninth register is electrically connected to the first control unit and the flight time measurement unit; the second hysteresis comparator is electrically connected to the first control unit; the first The second hysteresis comparator is used to compare the waveform intercept value of the current response voltage wave transmitted from the first waveform intercept detection unit with the maximum intercept value of the response voltage wave group recorded and maintained by the eighth register, and send the comparison result to the first control unit, the first control unit sends the comparison result to the control module, when the waveform intercept of the response voltage wave group attenuates beyond the attenuation threshold, the ninth register sends a waveform intercept attenuation flag signal to the fly-time measurement unit to make the fly-time measurement unit stop the current wave group measurement, and the ninth register sends a waveform intercept attenuation signal to the first control unit, the first control unit sends a waveform intercept attenuation interrupt signal to the control module, so that the control module reads the data measured by the fly-time measurement unit from the fly-time measurement unit; The eleventh register is electrically connected to the second comparator or the third comparator, the eleventh register is electrically connected to the twelfth register, the twelfth register is electrically connected to the thirteenth register, and the thirteenth register is electrically connected to the tenth register; The eleventh register is used to receive the comparator pulse signal transmitted by the second comparator or the third comparator, and the eleventh register and the twelfth register are used to perform two-level clock synchronization register delay on the comparator pulse signal so that the clock sampling of the comparator pulse signal transmitted to the thirteenth register is stable. The thirteenth register is electrically connected to the eighth register. The thirteenth register is used to generate a high-level pulse when the comparator pulse signal transmitted by the twelfth register changes from a high level to a low level to instruct the eighth register to update the saved data, otherwise the eighth register saves the data that has been transmitted to the eighth register. The high-level pulse generated by the thirteenth register is delayed by one clock cycle by the tenth register to instruct the ninth register to collect the result of the comparison output of the second hysteresis comparator and transmit the collected result to the first control unit, and the thirteenth register is also used to transmit the reset signal timing to the first waveform intercept detection unit.

10. The device for measuring the acoustic wave transit time according to claim 6, characterized in that: The acoustic wave feature detection unit includes a second control unit and a second waveform intercept detection unit; The second control unit is electrically connected to the second waveform intercept detection unit, and the second control unit is also electrically connected to the control module and the third comparator respectively; The second control unit is used to receive the comparator pulse signal output from the third comparator, and convert the comparator pulse signal into a conversion pulse signal that can be identified and detected by the second waveform intercept detection unit, and send it to the second waveform intercept detection unit. The second waveform intercept detection unit is used to detect the rising edge and the falling edge of the conversion pulse signal, and send the detection values ​​of the detected rising edge and the falling edge to the second control unit. The control module periodically and continuously reads the detection values ​​of the rising edge and the falling edge from the second control unit, and determines the waveform intercept value of each response voltage wave based on the detection values ​​of the rising edge and the falling edge to determine whether the waveform intercept of the response wave group is attenuated.

11. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave transit time also includes a pulse counting unit; The pulse counting unit is electrically connected to the control module and the comparator component respectively. The pulse counting unit is used to count the number of pulses transmitted to the pulse counting unit and transmit the counted number of pulses to the control module.

12. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The flight time measurement unit includes a third control unit, a time measurement unit and a data cache unit; The time measurement unit is electrically connected to the third control unit and the data cache unit respectively, the third control unit is electrically connected to the data cache unit, the time measurement unit is used to detect the start time and the stop time, and the data cache unit is used to cache the detected data; Wherein, the third control unit is electrically connected to the control module.

13. The device for measuring the acoustic wave transit time according to claim 12, characterized in that: The data cache unit includes at least two levels of cache register groups, and at least two levels of cache register groups are electrically connected to the third control unit; At least two levels of cache register groups include at least a first cache register group and a second cache register group, and the first cache register group and the second cache register group are both electrically connected to the third control unit; When the peak amplitude or waveform intercept of the response voltage wave begins to decay, the first buffer register group is used to store the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the last initial pulse in the initial pulse group; the second buffer register group is used to store the stop time of the acoustic wave flying corresponding to the acoustic wave excited by the second last initial pulse in the initial pulse group.

14. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave transit time further comprises a first output buffer and a second output buffer, and the transducer assembly comprises a first transducer and a second transducer; The first output buffer is electrically connected to the pulse generating unit and the first transducer respectively, and the second output buffer is electrically connected to the pulse generating unit and the second transducer respectively; One of the first transducer and the second transducer serves as an excitation transducer, and the other serves as a response transducer. When the first output buffer is configured as an output state and the second output buffer is configured as a cut-off state, the first output buffer provides an excitation voltage and a current for the first transducer, so that the first transducer serves as an excitation transducer and the second transducer serves as a response transducer. The first transducer generates and transmits a sound wave group, and the second transducer receives the sound wave group and generates a response voltage wave group. The response transducer is electrically connected to the comparator component and the sound wave feature detection unit. When the second output buffer is configured as an output state and the first output buffer is configured as a cut-off state, the second output buffer provides an excitation voltage and a current for the second transducer, so that the second transducer serves as an excitation transducer and the first transducer serves as a response transducer. The second transducer generates and transmits a sound wave group, and the first transducer receives the sound wave group and generates a response voltage wave group. The response transducer is electrically connected to the comparator component and the sound wave feature detection unit.

15. The device for measuring the acoustic wave transit time according to claim 14, characterized in that: The device for measuring the acoustic wave transit time also includes a measuring tube; The excitation transducer is arranged at the first end of the measuring tube, and the response transducer is arranged at the second end of the measuring tube.

16. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave transit time further comprises a third output buffer and a third transducer; The third output buffer is electrically connected to the pulse generating unit and the third transducer respectively, and the third transducer is electrically connected to the comparator component and the acoustic wave characteristic detecting unit; When the third output buffer is configured in the output state, the third output buffer provides the third transducer with an excitation voltage and a current, and the third transducer generates and transmits a sound wave group; when the third output buffer is configured in the cut-off state, the third output buffer stops providing the third transducer with an excitation voltage and a current, and the third transducer receives the sound wave group and generates a response voltage wave group.

17. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave flight time also includes an analog gate; The analog gate is electrically connected to the pulse generating unit and the transducer component, and the analog gate is electrically connected to the comparator component. The analog gate is switched on so that the initial pulse group emitted by the pulse generating unit is transmitted to the comparator component, or the response voltage wave group generated by the transducer component is transmitted to the comparator component.

18. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave transit time further comprises a first coupling capacitor and a second coupling capacitor, and the transducer assembly comprises a first transducer and a second transducer; The first coupling capacitor is electrically connected to the first transducer, and the second coupling capacitor is electrically connected to the second transducer; Wherein, when the first transducer serves as a response transducer, the first coupling capacitor is used to couple the response voltage of the first transducer to the comparator component and / or the acoustic wave characteristic detection unit; when the second transducer serves as a response transducer, the second coupling capacitor is used to couple the response voltage of the second transducer to the comparator component and / or the acoustic wave characteristic detection unit.

19. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The device for measuring the acoustic wave transit time also includes a third coupling capacitor and a third transducer; The third coupling capacitor is electrically connected to the third transducer; Wherein, when the third transducer is used as a response transducer, the third coupling capacitor is used to couple the response voltage of the third transducer to the comparator component and the acoustic wave characteristic detection unit, or to the comparator component.

20. A method for measuring acoustic wave transit time, characterized in that: Applicable to the device for measuring the acoustic wave transit time as described in any one of claims 1 to 19, the measuring method comprises: Determine the starting time of the acoustic wave flight; Determining the stop time of the acoustic wave flight; The flight time of the sound wave group is determined according to the start time and the stop time.

21. The method for measuring the acoustic wave transit time according to claim 20, characterized in that: The stop time includes at least two consecutive flyby stop times; Before determining the flight time of the sound wave group according to the start time and the stop time, the method for measuring the sound wave flight time further includes: Detecting whether the stop time is valid, if the stop time is valid, determining the flight time of the sound wave group according to the start time and the stop time; If the stop time is invalid, the stop time is re-determined until the stop time is valid.

22. The method for measuring the acoustic wave transit time according to claim 21, characterized in that: Detecting whether the stop time is valid includes: Subtract two consecutive fly-by stop times to obtain a fly-by stop time difference; compare the fly-by stop time difference with the emission period of the pulse generator to emit pulses, if the difference between the fly-by stop time difference and the emission period is within a preset difference range, then both of the two fly-by stop times are valid; if the difference between the fly-by stop time difference and the emission period is outside the preset difference range, then both of the two fly-by stop times are invalid; Or, subtract any two adjacent fly stop times from at least three consecutive fly stop times to obtain at least two fly stop time differences; compare any of the fly stop time differences with the emission period of the pulse emitted by the pulse generator; if the difference between the fly stop time difference and the emission period is within a preset difference range, then the two fly stop times corresponding to the fly stop time difference are both valid; if the difference between the fly stop time difference and the emission period is outside the preset difference range, then the two fly stop times corresponding to the fly stop time difference are both invalid.

23. The method for measuring the acoustic wave transit time according to claim 20, characterized in that: The flight time measuring device further includes a reference voltage generating unit, a first comparator or a third comparator, and a pulse counting unit; Before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the method for measuring the acoustic wave flight time further includes: Acquire a measured value of the pulse output from the first comparator or the third comparator measured by the pulse counting unit within a preset time period; Determining whether the measurement value is within a preset value range; If the measurement value is within the preset value range, the non-zero comparison reference voltage of the first comparator or the third comparator is not adjusted; If the metered value is not within the preset value range, and the metered value is less than the minimum value of the preset value range, the non-zero comparison reference voltage of the first comparator or the third comparator is reduced until the metered value is within the preset value range; if the metered value is greater than the maximum value of the preset value range, the non-zero comparison reference voltage of the first comparator or the third comparator is increased until the metered value is within the preset value range.

24. The method for measuring the acoustic wave transit time according to claim 20, characterized in that: The acoustic wave feature detection unit includes a first hysteresis comparator, the first hysteresis comparator has a first hysteresis comparison threshold, and before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method further includes: Determine the maximum value of the peak amplitude of the response voltage wave in the response voltage wave group, and the peak amplitude of the first attenuated wave when the response voltage wave in the response voltage wave group initially attenuates; Determine a peak amplitude attenuation difference between a maximum value of the peak amplitude of the response wave and a peak amplitude of the attenuated first wave; Based on the peak amplitude attenuation difference, it is determined whether a first hysteresis comparison threshold of the first hysteresis comparator meets the requirement.

25. The method for measuring the acoustic wave transit time according to claim 20, characterized in that: The acoustic wave feature detection unit includes a second hysteresis comparator, the second hysteresis comparator has a second hysteresis comparison threshold, and before determining the stop time of the flight time measurement, or before determining the start time of the flight time measurement, the acoustic wave flight time measurement method further includes: Determine the maximum value of the waveform intercept of the response voltage wave in the response voltage wave group, and the attenuation waveform intercept value of the attenuation first wave of the response voltage wave in the response voltage wave group when the response voltage wave initially attenuates; Determine the intercept attenuation difference between the maximum value of the waveform intercept of the response voltage wave and the intercept value of the decayed waveform of the decayed first wave; Based on the intercept attenuation difference, it is determined whether a second hysteresis comparison threshold of the second hysteresis comparator meets the requirement.

26. A device, characterized in that The device comprises the device for measuring the acoustic wave transit time according to any one of claims 1-19.

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