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 flying time measurement. Comprising a control module, a pulse generating unit, a transducer assembly, a span time measuring unit and a comparator, the span time measuring unit and the pulse generating unit are electrically connected with the control module; the pulse generating unit is electrically connected with the transducer assembly and the span time measuring unit, the transducer assembly is electrically connected with the comparator, the comparator is electrically connected with the span time measuring unit, and the transducer assembly is used for generating and transmitting a sound wave group and / or receiving the sound wave group; the pulse generation unit is used for generating and outputting a periodic initial pulse group, the transducer assembly is used for generating and transmitting a sound wave group, the transducer assembly is further used for generating a response voltage wave group when receiving the sound wave group, and the response voltage wave group can be transmitted to the comparator.

Description

Technical Field

[0001] This application belongs to the field of acoustic wave transit time measurement, and particularly relates to a measurement device, measurement method, and equipment for acoustic wave transit time. Background Art

[0002] With the development of technology, applications that measure using acoustic waves (including infrasonic waves, audible frequency acoustic waves, and ultrasonic waves) are becoming more and more widespread. Taking ultrasonic transit time measurement as an example, specifically, ultrasonic waves are transmitted in a measurement tube, and the transmission time is affected by factors such as the fluid type and flow rate of the fluid in the measurement tube. Therefore, by measuring the transit time of ultrasonic waves propagating in the measurement tube and combining parameters such as the propagation speed of ultrasonic waves in the fluid, parameter values such as the flow rate and flow volume of the fluid in the measurement tube can be determined. Among them, one or more sets of transducers are arranged at both ends of the measurement tube. When one end is used as an excitation transducer, the other end is used as a response transducer. After the excitation transducer is excited, it will generate ultrasonic waves. The ultrasonic waves propagate in the fluid in the measurement tube and then reach the response transducer. The time for the ultrasonic waves to propagate in the fluid in the measurement tube is regarded as the time interval from when the excitation transducer generates ultrasonic waves to when the response transducer receives the ultrasonic waves. The time for the ultrasonic waves to be transmitted in the fluid in the measurement tube is also called the ultrasonic transit time. However, in related technologies, the measurement devices and measurement methods for acoustic wave transit time for ultrasonic transit time measurement are relatively complex, which is not conducive to the engineering implementation and practical application of the measurement device. Summary of the Invention

[0003] The purpose of the embodiments of this application is to provide a measurement device, measurement method, and equipment for acoustic wave transit time, which at least solves the problem that the measurement devices and measurement methods for acoustic wave transit time for ultrasonic transit time measurement are relatively complex, and thus is more conducive to the engineering implementation and practical application of the measurement device.

[0004] In a first aspect, the embodiments of this application provide a measurement device for acoustic wave transit time. The measurement device for acoustic wave transit time includes: a control module, a pulse generation unit, a transducer assembly, a span time measurement unit, and a comparator;

[0005] The span time measurement unit and the pulse generation unit are both electrically connected to the control module; the pulse generation unit is respectively electrically connected to the transducer assembly and the span time measurement unit, the transducer assembly is electrically connected to the comparator, the comparator is electrically connected to the span time measurement unit, and 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 and output a periodic initial pulse group. The transducer assembly is used to generate and emit an acoustic wave group, and the transducer assembly 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 comparator;

[0007] The comparator is used to perform a non-zero comparison on the response voltage wave group to output a non-zero comparison pulse signal, and transmit the non-zero comparison pulse signal to the span time measuring unit;

[0008] The span time measuring unit is used to measure the count values of the reference span time of the leading edge and the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, so as to obtain the count value of the leading edge reference span time and the count value of the trailing edge reference span time;

[0009] The control module is used to determine the corresponding leading edge reference span time and trailing edge reference span time according to the leading edge reference span time count value and the trailing edge reference span time count value, and determine whether the response voltage wave decays according to the leading edge reference span time and / or the trailing edge reference span time. When the attenuation amount of the response voltage wave is greater than or equal to a preset attenuation threshold, stop measuring the acoustic wave transit time of the acoustic wave group, and determine the acoustic wave transit time of the acoustic wave group based on the leading edge reference span time and the trailing edge reference span time.

[0010] Optionally, the measuring device for the acoustic wave transit time further includes a pulse counting unit;

[0011] The pulse counting unit is electrically connected to the control module and the comparator respectively. The pulse counting unit is used to count the number of non-zero comparison pulse signals transmitted to the pulse counting unit, and transmit the counted number of non-zero comparison pulse signals to the control module.

[0012] Optionally, the span time measuring unit includes a first span measuring subunit and a second span measuring subunit;

[0013] The pulse generating unit is electrically connected to the first span measuring subunit and the second span measuring subunit respectively;

[0014] The first span measuring subunit is used to measure the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, so as to obtain the count value of the leading edge reference span time;

[0015] The second span measurement subunit is configured to measure the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, so as to obtain the trailing edge reference span time count value.

[0016] Optionally, the acoustic time-of-flight measurement device further includes a first output buffer and a second output buffer, and the transducer assembly includes a first transducer and a second transducer;

[0017] The first output buffer is electrically connected to the pulse generation unit and the first transducer respectively, and the second output buffer is electrically connected to the pulse generation unit and the second transducer respectively;

[0018] 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 to be in an output state and the second output buffer is configured to be in a cut-off state, the first output buffer provides an excitation voltage and 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 emits an acoustic wave group, the second transducer receives the acoustic wave group and generates a response voltage wave group, and the response transducer is electrically connected to the comparator; when the second output buffer is configured to be in an output state and the first output buffer is configured to be in a cut-off state, the second output buffer provides an excitation voltage and 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 emits an acoustic wave group, the first transducer receives the acoustic wave group and generates a response voltage wave group, and the response transducer is electrically connected to the comparator.

[0019] Optionally, the acoustic time-of-flight measurement device further includes a measurement tube;

[0020] One of the first transducer and the second transducer is disposed at the first end of the measurement tube, and the other is disposed at the second end of the measurement tube.

[0021] Optionally, the acoustic time-of-flight measurement device further includes a third output buffer, and the transducer assembly includes a third transducer;

[0022] The third output buffer is electrically connected to the pulse generation unit and the third transducer respectively.

[0023] Optionally, the acoustic time-of-flight measurement device further includes a reference voltage generation unit, which is electrically connected to the comparator, and the reference voltage generation unit is configured to transmit a reference voltage to the comparator.

[0024] Optionally, the measuring device for the acoustic wave transit time further includes a first coupling capacitor and a second coupling capacitor, and the transducer assembly includes a first transducer and a second transducer;

[0025] The first coupling capacitor is electrically connected to the first transducer, and the second coupling capacitor is electrically connected to the second transducer;

[0026] Wherein, when the first transducer is used as the response transducer, the first coupling capacitor is used to couple the response voltage of the first transducer to the comparator; when the second transducer is used as the response transducer, the second coupling capacitor is used to couple the response voltage of the second transducer to the comparator.

[0027] Optionally, the measuring device for the acoustic wave transit time further includes a third coupling capacitor, and the transducer assembly includes a third transducer;

[0028] The third coupling capacitor is electrically connected to the third transducer;

[0029] Wherein, when the third transducer is used as the response transducer, the third coupling capacitor is used to couple the response voltage of the third transducer to the comparator.

[0030] In a second aspect, an embodiment of the present application provides a method for measuring the acoustic wave span time, which is applied to the measuring device for the acoustic wave transit time according to any one of the first aspects above. The measuring method includes:

[0031] Obtain a first measurement value and a second measurement value of the span time measurement unit. The first measurement value includes the leading-edge reference span time count value of the non-zero comparison pulse, and the second measurement value includes the trailing-edge reference span time count value of the non-zero comparison pulse;

[0032] Based on the first measurement value, determine the leading-edge reference span time of the non-zero comparison pulse and use it as the first reference span time, and based on the second measurement value, determine the trailing-edge reference span time of the non-zero comparison pulse and use it as the second reference span time;

[0033] Based on the first reference span time and / or the second reference span time, determine whether the response voltage wave is attenuated;

[0034] When the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold, stop measuring the acoustic wave transit time of the acoustic wave group, and determine the acoustic wave transit time of the acoustic wave group based on the first reference span time and the second reference span time.

[0035] Optionally, the determining the acoustic wave transit time of the acoustic wave group based on the first reference span time and the second reference span time includes:

[0036] Add the first reference span time and the second reference span time to obtain a first time value, and determine a time value that is half of the first time value, thereby obtaining a second time value;

[0037] Determine the acoustic wave transit time according to the second time value and the pulse period of the initial pulse train.

[0038] Optionally, the determining the acoustic wave transit time according to the second time value and the pulse period of the initial pulse train includes:

[0039] Determine the sum of the second time value and one-fourth of the pulse period of the initial pulse train to obtain a third time value;

[0040] Determine the acoustic wave transit time according to the third time value.

[0041] Optionally, the determining the acoustic wave transit time according to the second time value and the pulse period of the initial pulse train includes:

[0042] Determine the difference between the second time value and one-fourth of the pulse period of the initial pulse train to obtain a fourth time value;

[0043] Determine the acoustic wave transit time according to the fourth time value.

[0044] Optionally, the determining whether the response voltage wave attenuates based on the first reference span time and / or the second reference span time includes:

[0045] Determine N consecutive first reference span times, where the N first reference span times are sorted in order of time, and N is a positive integer greater than or equal to 2;

[0046] Determine the difference between any two adjacent first reference span times among the N first reference span times to obtain at least one first difference, and the first difference is: the difference between the second first reference span time and the first first reference span time among two adjacent first reference span times;

[0047] Successively determine the difference between at least one of the first differences and the pulse period of the initial pulse train to obtain the corresponding at least one first target difference;

[0048] Determine whether the response voltage wave attenuates based on at least one of the first target differences.

[0049] Optionally, the determining whether the response voltage wave attenuates based on at least one of the first target differences includes:

[0050] Determine whether there is a first target difference greater than or equal to a first preset difference threshold among at least one of the first target differences; if there is a first target difference greater than or equal to the first preset difference threshold among at least one of the first target differences, determine that the response voltage wave group has attenuation.

[0051] Optionally, determining whether the response voltage wave has attenuation based on the first reference span time and / or the second reference span time includes:

[0052] Determine N consecutive second reference span times, and the N second reference span times are sorted in order of time;

[0053] Determine the difference between any two adjacent second reference span times among the N second reference span times to obtain at least one of the second differences, and the second difference is: the difference between the second second reference span time and the first second reference span time among two adjacent second reference span times;

[0054] Successively determine the difference between at least one of the second differences and the pulse period of the initial pulse group to obtain the corresponding at least one second target difference;

[0055] Based on at least one of the second target differences, determine whether the response voltage wave has attenuation.

[0056] Optionally, determining whether the response voltage wave has attenuation based on at least one of the second target differences includes:

[0057] Determine whether there is a second target difference less than a second preset difference threshold among at least one of the second target differences; if there is a second target difference less than the second preset difference threshold among at least one of the second target differences, determine that the response voltage wave group has attenuation.

[0058] Optionally, determining whether the response voltage wave has attenuation based on the first reference span time and / or the second reference span time includes:

[0059] Determine N consecutive first reference span times, and the N first reference span times are sorted in order of time;

[0060] Determine the difference between any two adjacent first reference span times among the N first reference span times to obtain a plurality of the first differences, and the first difference is: the difference between the second first reference span time and the first first reference span time among two adjacent first reference span times;

[0061] Determine the difference between the second first difference and the first first difference among two adjacent first differences among the plurality of first differences to obtain the corresponding plurality of third target differences;

[0062] Based on multiple said third target differences, determine whether the response voltage wave attenuates.

[0063] Optionally, the determining whether the response voltage wave attenuates based on multiple said third target differences includes:

[0064] Determine whether the absolute value of the first said third target difference is less than a third preset difference threshold and whether the second said third target difference is greater than or equal to a fourth preset difference threshold among two consecutive said third target differences; if, among two consecutive said third target differences, the absolute value of the first said third target difference is less than the third preset difference threshold and the second said third target difference is greater than or equal to the fourth preset difference threshold, then determine that the response voltage wave group attenuates.

[0065] Optionally, the determining whether the response voltage wave attenuates based on the first reference span time and / or the second reference span time includes:

[0066] Determine N consecutive said second reference span times, and the N second reference span times are sorted in sequence according to time;

[0067] Determine the differences between any two adjacent second reference span times among the N second reference span times to obtain multiple said second differences, and the second difference is: the difference between the second second reference span time and the first second reference span time among two adjacent second reference span times;

[0068] Determine the difference between the second second difference and the first second difference among two adjacent second differences among multiple said second differences to obtain corresponding multiple fourth target differences;

[0069] Based on multiple said fourth target differences, determine whether the response voltage wave attenuates.

[0070] Optionally, the determining whether the response voltage wave attenuates based on multiple said fourth target differences includes:

[0071] Determine whether the absolute value of the first said fourth target difference is less than a fifth preset difference threshold and whether the second said fourth target difference is less than a sixth preset difference threshold among two consecutive said fourth target differences; if, among two consecutive said fourth target differences, the absolute value of the first said fourth target difference is less than the fifth preset difference threshold and the second said fourth target difference is less than the sixth preset difference threshold, then determine that the response voltage wave group attenuates.

[0072] Optionally, the determining whether the response voltage wave attenuates based on the first reference span time and / or the second reference span time includes:

[0073] Determine the difference between the second reference span time and the first reference span time as the first time difference;

[0074] Determine N consecutive first time differences, and the N first time differences are sorted in sequence according to time;

[0075] Determine the difference between the second first time difference and the first time difference among any two adjacent first time differences in the N first time differences to obtain at least one corresponding fifth target difference;

[0076] Based on at least one of the fifth target differences, determine whether the response voltage wave group decays.

[0077] Optionally, the determining whether the response voltage wave group decays based on at least one of the fifth target differences includes:

[0078] If there is a fifth target difference less than a seventh preset difference threshold among at least one of the fifth target differences, determine that the response voltage wave group decays.

[0079] Optionally, the determining whether the response voltage wave group decays based on at least one of the fifth target differences includes:

[0080] If, among two consecutive fifth target differences, the absolute value of the first fifth target difference is less than an eighth preset difference threshold and the second fifth target difference is less than the seventh preset difference threshold, determine that the response voltage wave group decays.

[0081] If there is a fifth target difference less than the seventh preset difference threshold among multiple fifth target differences, determine that the response voltage wave group decays.

[0082] In a third aspect, an embodiment of the present application provides a device, and the device includes the measuring device for the acoustic wave flight time according to any one of the above first aspects.

[0083] In the embodiment of the present application, the control module determines the corresponding leading-edge reference span time and trailing-edge reference span time based on the leading-edge reference span time count value and trailing-edge reference span time count value of the non-zero comparison pulse, and determines whether the response voltage wave decays according to the leading-edge reference span time and / or trailing-edge reference span time. When the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold, the measurement of the acoustic wave transit time of the acoustic wave group is stopped. The control module can use a time point of the target response wave before the time when the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold as the stop time of the acoustic wave transit. After that, the control module determines the stop time of the acoustic wave transit of the acoustic wave group based on the count value of the reference span time of the non-zero comparison pulse. This stop time is an accurate time, and the start time of the acoustic wave transit is determined and accurate. Therefore, based on the accurate start time and accurate stop time, the acoustic wave transit time can be accurately determined, and then other corresponding parameters can be accurately determined according to the accurate acoustic wave transit time. Moreover, the structure of the device for measuring the acoustic wave transit time is relatively simple, and the principle and method for measuring the acoustic wave transit time are also relatively simple. That is, in the embodiment of the present application, not only can the acoustic wave transit time be accurately determined, but also the structure of the device for measuring the acoustic wave transit time is relatively simple, and the method for measuring the acoustic wave transit time is also relatively simple, which is beneficial to engineering implementation and practical application. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 FIG. shows a schematic diagram of a device for measuring the acoustic wave transit time provided by an embodiment of the present application;

[0085] Figure 2 FIG. shows a schematic diagram of using the device for measuring the acoustic wave transit time provided by an embodiment of the present application to measure the flow rate of a fluid;

[0086] Figure 3 FIG. shows a schematic diagram of using the device for measuring the acoustic wave transit time provided by an embodiment of the present application to measure the distance;

[0087] Figure 4 FIG. shows a schematic diagram of the span time measurement in the device for measuring the acoustic wave transit time provided by an embodiment of the present application including two sub-units;

[0088] Figure 5 FIG. shows a schematic diagram of the principle of measuring the transit time by the device for measuring the acoustic wave transit time provided by an embodiment of the present application;

[0089] Figure 6 FIG. shows a schematic diagram of the principle of measuring the attenuation of the response voltage wave by the device for measuring the acoustic wave transit time provided by an embodiment of the present application;

[0090] Figure 7 FIG. shows a flowchart of a method for measuring the acoustic wave transit time provided by an embodiment of the present application.

[0091] Reference numerals:

[0092] 10: Control module; 11: Host computer; 12: Integrated control unit; 20: Pulse generation unit; 30: Transducer assembly; 31: First transducer; 32: Second transducer; 33: Third transducer; 40: Span time measurement unit; 41: First span measurement subunit; 42: Second span measurement subunit; 50: Comparator; 60: Pulse counting unit; 70: Analog switch; 80: Reference voltage generation unit; 91: First output buffer; 92: Second output buffer; 93: Third output buffer; 101: First coupling capacitor; 102: Second coupling capacitor; 103: Third coupling capacitor; 110: Measurement tube. Detailed implementation manners

[0093] The terms "first" and "second" in the description and claims of this application may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.

[0094] In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0095] 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0096] Such as Figures 1 to 6As shown in the figure, the measurement device for the acoustic wave transit time includes: a control module 10, a pulse generation unit 20, a transducer assembly 30, a span time measurement unit 40, and a comparator 50.

[0097] The span time measurement unit 40 and the pulse generation unit 20 are both electrically connected to the control module 10; the pulse generation unit 20 is electrically connected to the transducer assembly 30 and the span time measurement unit 40 respectively, the transducer assembly 30 is electrically connected to the comparator 50, the comparator 50 is electrically connected to the span time measurement unit 40, and the transducer assembly 30 is used to generate and transmit an acoustic wave group, and / or receive an acoustic wave group; the pulse generation unit 20 is used to generate and output a periodic initial pulse group, the transducer assembly 30 is used to generate and transmit an acoustic wave group, and the transducer assembly 30 is also used to generate a response voltage wave group when receiving an acoustic wave group, and the response voltage wave group can be transmitted to the comparator 50; the comparator 50 is used to perform a non-zero comparison on the response voltage wave group to output a non-zero comparison pulse signal and transmit the non-zero comparison pulse signal to the span time measurement unit 40; the span time measurement unit 40 is used to measure the count values of the leading edge and the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group to obtain the leading edge reference span time count value and the trailing edge reference span time count value; the control module 10 is used to determine the corresponding leading edge reference span time and trailing edge reference span time according to the leading edge reference span time count value and the trailing edge reference span time count value, and determine whether the response voltage wave decays according to the leading edge reference span time and / or the trailing edge reference span time, and when the attenuation amount of the response voltage wave is greater than or equal to a preset attenuation threshold, stop measuring the acoustic wave transit time of the acoustic wave group, and determine the acoustic wave transit time of the acoustic wave group based on the leading edge reference span time and the trailing edge reference span time.

[0098] In the embodiment of the present application, since the span time measurement unit 40 and the pulse generation unit 20 are both electrically connected to the control module 10, the span time measurement unit 40 and the pulse generation unit 20 can both be controlled by the control module 10, or send signals to the control module 10, or the control module 10 can obtain the required data from the span time measurement unit 40 and the pulse generation unit 20. Since the pulse generation unit 20 is electrically connected to the transducer assembly 30 and the span time measurement unit 40 respectively, once the pulse generation unit 20 generates an initial pulse train, the initial pulse train can be transmitted to the span time measurement unit 40 and the transducer assembly 30. The span time measurement unit 40 can receive the initial pulse train and use the time when the initial pulse train is received as the starting time of the acoustic wave transit. After the transducer assembly 30 receives the initial pulse train, the transducer assembly 30 can be excited to generate an acoustic wave train, and the transducer assembly 30 will generate a response voltage wave train when it receives the acoustic wave train. Since the transducer assembly 30 is electrically connected to the comparator 50, once the transducer assembly 30 generates a response voltage wave train, the response voltage wave train can be transmitted to the comparator 50, and the comparator 50 can perform a non-zero comparison to output a non-zero comparison pulse signal. Since the comparator 50 is electrically connected to the span time measurement unit 40, the comparator 50 can transmit the non-zero comparison pulse signal to the span time measurement unit 40. The span time measurement unit 40 can measure the count values of the reference span time of the leading edge and the trailing edge of the non-zero comparison pulse signal of the response voltage wave train relative to the target edge of the selected pulse signal in the initial pulse train to obtain the count value of the leading edge reference span time and the count value of the trailing edge reference span time. The control module 10 can obtain the count value of the leading edge reference span time and the count value of the trailing edge reference span time, and determine the corresponding leading edge reference span time and trailing edge reference span time according to the count value of the leading edge reference span time and the count value of the trailing edge reference span time. Determine whether the response voltage wave is attenuated according to the leading edge reference span time and / or the trailing edge reference span time, and when the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold, stop measuring the acoustic wave transit time of the acoustic wave train, and determine the acoustic wave transit time of the acoustic wave train based on the leading edge reference span time and the trailing edge reference span time.

[0099] That is to say, in the embodiment of the present application, the control module 10 determines the corresponding leading-edge reference span time and trailing-edge reference span time based on the leading-edge reference span time count value and the trailing-edge reference span time count value of the non-zero comparison pulse, and determines whether the response voltage wave decays according to the leading-edge reference span time and / or the trailing-edge reference span time. When the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold, the measurement of the acoustic wave transit time of the acoustic wave group is stopped. The control module 10 may use a time point of the target response wave before the time when the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold as the stop time of the acoustic wave transit. After that, the control module 10 determines the stop time of the acoustic wave transit of the acoustic wave group based on the count value of the reference span time of the non-zero comparison pulse. This stop time is an accurate time, and the start time of the acoustic wave transit is determined and accurate. Therefore, based on the accurate start time and accurate stop time, the acoustic wave transit time can be accurately determined, and then other corresponding parameters can be accurately determined according to the accurate acoustic wave transit time. Moreover, the structure of the device for measuring the acoustic wave transit time is relatively simple, and the principle and method for measuring the acoustic wave transit time are also relatively simple. That is to say, in the embodiment of the present application, not only can the acoustic wave transit time be accurately determined, but also the structure of the device for measuring the acoustic wave transit time is relatively simple, and the method for measuring the acoustic wave transit time is also relatively simple, which is conducive to engineering implementation and practical application.

[0100] It should be noted that after the pulse generating unit 20 generates an initial pulse train, the initial pulse train is transmitted to the transducer assembly 30, which can then excite the transducer assembly 30 to generate an acoustic wave train. After the transducer assembly 30 that is not driven by the pulse generating unit 20 receives the acoustic wave train, a response voltage wave train is generated. The response voltage waves in the response voltage wave train are usually quasi-sinusoidal waves. In this process, that is, when the initial pulse train is transmitted to the transducer assembly 30, the transducer assembly 30 generates and emits an acoustic wave train, and the acoustic wave train is transmitted to the transducer assembly 30, causing the transducer assembly 30 that is not driven by the pulse generating unit 20 to generate a response voltage wave train. This is equivalent to the initial pulse train continuously exciting the transducer assembly 30, and the transducer assembly 30 continuously generates and emits an acoustic wave train. When the transducer assembly 30 that is not excited by the initial pulse train receives the continuous acoustic wave train, it is continuously excited to generate a response voltage wave train. The peak amplitude of the response voltage waves in the generated response voltage wave train will necessarily increase gradually until the transducer assembly 30 reaches a resonance or oscillation state with the same frequency as the initial pulse. At this time, the peak amplitude of the response voltage waves in the response voltage wave train reaches the maximum value. Once the pulse generating unit 20 stops generating the initial pulse train, which is equivalent to stopping the energy output to the transducer assembly 30, the transducer assembly 30 used as the excitation transducer immediately stops generating and emitting acoustic waves. As a result, the transducer assembly 30 used as the response transducer no longer receives acoustic waves and loses the excitation kinetic energy, causing the transducer oscillation to immediately start to decay. Consequently, the response voltage waves in the response voltage wave train will necessarily start to decay, that is, the peak amplitude of the response voltage waves will necessarily start to decay. With the non-zero comparison reference voltage remaining unchanged, the pulse span time of the non-zero comparison pulses of the response voltage waves will necessarily decay. Based on the reference span time of the non-zero comparison pulses, the control module 10 can determine whether the response voltage waves show decay. When the decay amount of the response voltage waves is greater than or equal to the preset decay threshold, the measurement of the acoustic wave flight time of the acoustic wave train is stopped, and the stop time is determined. The start time of the acoustic wave flight is controlled by the control module 10 and is determined and accurate. Thus, the accurate acoustic wave flight time can be determined.

[0101] It should also be noted that in the embodiment of the present application, the transducer assembly 30 is an energy conversion device that can work bidirectionally. It can be excited by the initial pulse train to emit acoustic waves and can also receive acoustic waves to be excited to generate a response voltage wave train. That is, after the transducer assembly 30 driven by the pulse generating unit 20 receives the initial pulse train, the transducer assembly 30 can be excited to oscillate to generate and emit an acoustic wave train, and the transducer assembly 30 that is not driven by the pulse generating unit 20 will be excited to oscillate to generate a response voltage wave train when it receives the acoustic wave train.

[0102] In addition, in the embodiments of the present application, when measuring the count value of the reference span time of the leading edge and the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, the target edge of the selected pulse signal in the initial pulse group may be the leading edge. Of course, the target edge may also be the trailing edge, and the present application does not make any limitations here.

[0103] When the target edge is the leading edge, it is equivalent to measuring the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the leading edge of the selected pulse signal in the initial pulse group to obtain the leading edge reference span time; measuring the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the leading edge of the selected pulse signal in the initial pulse group to obtain the trailing edge reference span time; when the target edge is the trailing edge, it is equivalent to measuring the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the trailing edge of the selected pulse signal in the initial pulse group to obtain the leading edge reference span time; measuring the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the trailing edge of the selected pulse signal in the initial pulse group to obtain the trailing edge reference span time; for the sake of simplicity in principle expression, in the embodiments of the present application, the basic principle and method of the present application are illustrated with the target edge of the selected pulse signal in the initial pulse group being the leading edge.

[0104] In addition, in the embodiments of the present application, the leading edge of the non-zero comparison pulse may be the rising edge of the pulse, and the trailing edge may be the falling edge of the pulse. Of course, the leading edge may be the falling edge of the pulse, and the trailing edge may be the rising edge of the pulse. The present application does not make any limitations here; in the embodiments of the present application, for the sake of simplicity in principle expression, the leading edge of the non-zero comparison pulse is selected as the rising edge of the pulse, and the trailing edge is the falling edge of the pulse to illustrate the principle.

[0105] In addition, in the embodiments of the present application, the control module 10 determines the corresponding leading edge reference span time and trailing edge reference span time according to the leading edge reference span time count value and the trailing edge reference span time count value. Specifically, the control module 10 may multiply the leading edge reference span time count value by the counting time resolution of the span time measurement unit 40 to obtain the leading edge reference span time, and multiply the trailing edge reference span time count value by the counting time resolution of the span time measurement unit 40 to obtain the trailing edge reference span time.

[0106] In addition, in the embodiment of the present application, the control module 10 is further configured to: obtain the first measurement value and / or the second measurement value of the span time measurement unit 40, where the first measurement value includes the leading-edge reference span time count value of the non-zero comparison pulse, and the second measurement value includes the trailing-edge reference span time count value of the non-zero comparison pulse; determine the leading-edge reference span time of the non-zero comparison pulse based on the first measurement value, and use it as the first reference span time, and determine the trailing-edge reference span time of the non-zero comparison pulse based on the second measurement value, and use it as the second reference span time; determine whether the response voltage wave decays based on the first reference span time and / or the second reference span time; when the attenuation amount of the response voltage wave is greater than or equal to a preset attenuation threshold, stop measuring the acoustic wave transit time of the acoustic wave group, and determine the acoustic wave transit time of the acoustic wave group based on the first reference span time and the second reference span time.

[0107] In addition, in the embodiment of the present application, the control module 10 is further configured to: add the first reference span time and the second reference span time to obtain a first time value, and determine a time value that is half of the first time value, so as to obtain a second time value; determine the acoustic wave transit time according to the second time value and the pulse period of the initial pulse group.

[0108] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine the sum of the second time value and one-fourth of the pulse period of the initial pulse group to obtain a third time value; determine the acoustic wave transit time according to the third time value.

[0109] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine the difference between the second time value and one-fourth of the pulse period of the initial pulse group to obtain a fourth time value; determine the acoustic wave transit time according to the fourth time value.

[0110] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine N consecutive first reference span times, where the N first reference span times are sorted in time sequence, and N is a positive integer greater than or equal to 2; determine the difference between any two adjacent first reference span times among the N first reference span times to obtain at least one first difference, and the first difference is: the difference between the second first reference span time and the first first reference span time among two adjacent first reference span times; sequentially determine the difference between at least one first difference and the pulse period of the initial pulse group to obtain the corresponding at least one first target difference; determine whether the response voltage wave decays based on the at least one first target difference.

[0111] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine whether there is a first target difference greater than or equal to a first preset difference threshold among at least one first target difference; if there is a first target difference greater than or equal to the first preset difference threshold among at least one first target difference, determine that the response voltage wave group has attenuation.

[0112] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine N consecutive second reference span times, and the N second reference span times are sorted in sequence according to time; determine the difference between any two adjacent second reference span times among the N second reference span times to obtain at least one second difference, and the second difference is: the difference between the second second reference span time and the first second reference span time among two adjacent second reference span times; determine the difference between at least one second difference and the pulse period of the initial pulse group in sequence to obtain corresponding at least one second target difference; based on the at least one second target difference, determine whether the response voltage wave decays.

[0113] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine whether there is a second target difference less than a second preset difference threshold among at least one second target difference; if there is a second target difference less than the second preset difference threshold among at least one second target difference, determine that the response voltage wave group has attenuation.

[0114] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine N consecutive first reference span times, and the N first reference span times are sorted in sequence according to time; determine the difference between any two adjacent first reference span times among the N first reference span times to obtain a plurality of first differences, and the first difference is: the difference between the second first reference span time and the first first reference span time among two adjacent first reference span times; determine the difference between the second first difference and the first first difference among two adjacent first differences in the plurality of first differences to obtain corresponding a plurality of third target differences; based on the plurality of third target differences, determine whether the response voltage wave decays.

[0115] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine whether the absolute value of the first third target difference is less than a third preset difference threshold and whether the second third target difference is greater than or equal to a fourth preset difference threshold among two consecutive third target differences; if, among two consecutive third target differences, the absolute value of the first third target difference is less than the third preset difference threshold and the second third target difference is greater than or equal to the fourth preset difference threshold, determine that the response voltage wave group has attenuation.

[0116] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine N consecutive second reference span times, and the N second reference span times are sorted in sequence according to time; determine the difference between any two adjacent second reference span times among the N second reference span times to obtain a plurality of second differences, and the second difference is: the difference between the second second reference span time and the first second reference span time among two adjacent second reference span times; determine the difference between the second second difference and the first second difference among two adjacent second differences in the plurality of second differences to obtain corresponding plurality of fourth target differences; based on the plurality of fourth target differences, determine whether the response voltage wave decays.

[0117] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine whether the absolute value of the first fourth target difference is less than a fifth preset difference threshold and whether the second fourth target difference is less than a sixth preset difference threshold among two consecutive fourth target differences; if, among two consecutive fourth target differences, the absolute value of the first fourth target difference is less than the fifth preset difference threshold and the second fourth target difference is less than the sixth preset difference threshold, then determine that the response voltage wave group decays.

[0118] In addition, in the embodiment of the present application, the control module 10 is further configured to: determine the difference between the second reference span time and the first reference span time as a first time difference; determine N consecutive first time differences, and the N first time differences are sorted in sequence according to time; determine the difference between the second first time difference and the first time difference among any two adjacent first time differences in the N first time differences to obtain corresponding at least one fifth target difference; based on the at least one fifth target difference, determine whether the response voltage wave group decays.

[0119] In addition, in the embodiment of the present application, the control module 10 is further configured to: if there is a fifth target difference less than a seventh preset difference threshold among the at least one fifth target difference, then determine that the response voltage wave group decays.

[0120] In addition, in the embodiment of the present application, the control module 10 is further configured to: if, among two consecutive fifth target differences, the absolute value of the first fifth target difference is less than an eighth preset difference threshold and the second fifth target difference is less than the seventh preset difference threshold, then determine that the response voltage wave group decays.

[0121] In addition, in the embodiments of the present application, the span time measurement unit 40 may include a first span measurement subunit 41 and a second span measurement subunit 42; the pulse generation unit 20 is electrically connected to the first span measurement subunit 41 and the second span measurement subunit 42 respectively; the first span measurement subunit 41 is configured to measure the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, so as to obtain the leading edge reference span time count value; the second span measurement subunit 42 is configured to measure the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, so as to obtain the trailing edge reference span time count value. Through such an arrangement, it is equivalent to only measuring the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group by the first span measurement subunit 41, and only measuring the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group by the second span measurement subunit 42, so that the first span measurement subunit 41 and the second span measurement subunit 42 are respectively responsible for the counting measurement of one edge of the non-zero comparison pulse, and the circuit implementations of the first span measurement subunit 41 and the second span measurement subunit 42 are relatively simple.

[0122] Of course, in the embodiments of the present application, the span time measurement unit 40 may only include the first span measurement subunit 41, and the first span measurement subunit 41 is used to simultaneously measure the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, and the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group. Similarly, the span time measurement unit 40 may also only include the second span measurement subunit 42, and the second span measurement subunit 42 is used to simultaneously measure the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group, and the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the selected pulse signal in the initial pulse group.

[0123] In addition, in some embodiments, the acoustic wave transit time measurement device may further include an analog gate 70; the analog gate 70 is electrically connected to the pulse generation unit 20 and the transducer assembly 30, and the analog gate 70 is electrically connected to the comparator 50. The analog gate 70 switches to conduction to enable the excitation voltage wave group corresponding to the initial pulse group emitted by the pulse generation unit 20 to be transmitted to the comparator 50, or to enable the response voltage wave group generated by the transducer assembly 30 to be transmitted to the comparator 50.

[0124] Among them, the analog switch 70 can be configured to switch the input signal source to be conducted. Thus, when the excitation voltage wave group corresponding to the initial pulse group emitted by the pulse generation unit 20 is transmitted to the analog switch 70, the analog switch 70 can be configured such that the excitation voltage wave group is conducted, and then the excitation voltage wave group is transmitted to the comparator 50, so that the initial pulse group can trigger the span time measurement unit 40 to start measuring and counting the span time. Once part or all of the initial pulse group is transmitted, the analog switch 70 can be configured to disconnect the path for transmitting the initial pulse group, so that the excitation voltage wave group cannot pass through the analog switch 70 and thus cannot be continuously transmitted to the comparator 50. And the analog switch 70 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 50, and further the response voltage wave group can trigger the span time measurement unit 40 to perform measurement counting sampling to obtain the count value of the corresponding span time.

[0125] It should be noted that the analog switch 70 is electrically connected to the response transducer and can also be electrically connected to the excitation transducer.

[0126] It should also be noted that based on the functional role of the analog switch 70 in the embodiments of the present application, a circuit that uses other basic circuit devices such as analog switches to achieve the same function as the analog switch 70 can also be derived. Those skilled in the art can flexibly set it according to the needs of the actual device and the feasibility of various basic circuit devices. The present application does not make any limitations in this regard.

[0127] In addition, in some embodiments, the acoustic wave transit time measurement device may further include a first output buffer 91 and a second output buffer 92. The transducer assembly 30 includes a first transducer 31 and a second transducer 32. The first output buffer 91 is electrically connected to the pulse generation unit 20 and the first transducer 31 respectively, and the second output buffer 92 is electrically connected to the pulse generation unit 20 and the second transducer 32 respectively. One of the first transducer 31 and the second transducer 32 serves as an excitation transducer, and the other serves as a response transducer. When the first output buffer 91 is configured to be in an output state and the second output buffer 92 is configured to be in a cut-off state, the first output buffer 91 provides an excitation voltage and current to the first transducer 31, so that the first transducer 31 serves as an excitation transducer, the second transducer 32 serves as a response transducer, the first transducer 31 generates and emits an acoustic wave packet, the second transducer 32 receives the acoustic wave packet and generates a response voltage wave packet, and the response transducer is electrically connected to the comparator 50. When the second output buffer 92 is configured to be in an output state and the first output buffer 91 is configured to be in a cut-off state, the second output buffer 92 provides an excitation voltage and current to the second transducer 32, so that the second transducer 32 serves as an excitation transducer, the first transducer 31 serves as a response transducer, the second transducer 32 generates and emits an acoustic wave packet, the first transducer 31 receives the acoustic wave packet and generates a response voltage wave packet, and the response transducer is electrically connected to the comparator 50.

[0128] Since the first output buffer 91 is electrically connected to the pulse generating unit 20 and the first transducer 31 respectively, and the second output buffer 92 is electrically connected to the pulse generating unit 20 and the second transducer 32 respectively, the functions of the first transducer 31 and the second transducer 32 can be switched by configuring the states of the first output buffer 91 and the second output buffer 92. Specifically, when the first output buffer 91 is configured to be in the output state and the second output buffer 92 is configured to be in the cut-off state, the first output buffer 91 can provide the excitation voltage and current for the first transducer 31, and the second output buffer 92 does not provide the excitation voltage and current for the second transducer 32. Thus, the first transducer 31 is excited to act as the excitation transducer, and the second transducer 32 acts as the response transducer. The first transducer 31 generates and emits a group of acoustic waves. After the group of acoustic waves is transmitted, the second transducer 32 can receive the group of acoustic waves and generate a response voltage wave group. Since the response transducer is electrically connected to the comparator 50, the response voltage group can be transmitted to the comparator 50. When the second output buffer 92 is configured to be in the output state and the first output buffer 91 is configured to be in the cut-off state, the second output buffer 92 can provide the excitation voltage and current for the second transducer 32, and the first output buffer 91 does not provide the excitation voltage and current for the first transducer 31. Thus, the second transducer 32 is excited to act as the excitation transducer, and the first transducer 31 acts as the response transducer. The second transducer 32 generates and emits a group of acoustic waves. After the group of acoustic waves is transmitted, the first transducer 31 can receive the group of acoustic waves and generate a response voltage wave group. Since the response transducer is electrically connected to the comparator 50, the response voltage wave group can be transmitted to the comparator 50.

[0129] It should be noted that in the embodiment of the present application, a ranging device using the acoustic wave flight time can be used for ranging. At this time, the first output buffer 91 can be made to provide the excitation voltage and current for the first transducer 31, and the second output buffer 92 is in the cut-off state. The first transducer 31 acts as the excitation transducer, and the second transducer 32 acts as the response transducer. After the excitation transducer emits acoustic waves, the acoustic waves are transmitted to the obstacle and reflected by the obstacle. Thus, the acoustic waves are transmitted to the response transducer, and the response transducer can generate a response voltage wave when receiving the acoustic waves. In the embodiment of the present application, the flight time of the acoustic wave can be accurately determined, and using the speed of acoustic wave transmission in the current medium, the distance between the excitation transducer and the obstacle can be accurately determined. For example, by installing the ranging device using the acoustic wave flight time in the embodiment of the present application on a vehicle, a ship, or a submarine, the distance between the ranging device using the acoustic wave flight time and the obstacle can be relatively accurately determined.

[0130] In addition, in some embodiments, the acoustic wave transit time measurement device may further include a measurement tube 110; one of the first transducer 31 and the second transducer 32 is disposed at the first end of the measurement tube 110, and the other is disposed at the second end of the measurement tube 110.

[0131] With such an arrangement, after the excitation transducer emits an acoustic wave, the acoustic wave travels through the fluid in the measurement tube 110, and then the response transducer can receive the acoustic wave, so that the response transducer generates a response voltage wave group. With the acoustic wave transit time measurement device in the embodiments of the present application, the transit time of the acoustic wave can be accurately determined, and then the flow velocity of the fluid in the measurement tube 110 can be accurately determined, so as to more accurately determine parameters such as the flow rate.

[0132] It should be noted that when the acoustic wave transit time measurement device includes the measurement tube 110, at this time, the flow velocity of the fluid in the measurement tube 110 can also be accurately determined, and then parameters such as the flow rate can be more accurately determined. Thus, the measurement device provided in the embodiments of the present application can be applied to a water meter to more accurately determine parameters such as the flow velocity and flow rate of the water flowing through the measurement tube 110.

[0133] In addition, in some embodiments, the acoustic wave transit time measurement device may further include a third output buffer 93, and the transducer assembly 30 may include a third transducer 33; the third output buffer 93 is electrically connected to the pulse generation unit 20 and the third transducer 33 respectively.

[0134] The third output buffer 93 is electrically connected to the pulse generation unit 20 and the third transducer 33 respectively, and the third transducer 33 is electrically connected to the comparator 50; when the third output buffer 93 is configured to be in an output state, the third output buffer 93 provides an excitation voltage and current for the third transducer 33, and the third transducer 33 generates and emits an acoustic wave group; when the third output buffer 93 is configured to be in a cut-off state, the third output buffer 93 stops providing the excitation voltage and current for the third transducer 33. At this time, the third transducer 33 serves as a response transducer, and when the third transducer 33 receives the acoustic wave group, it generates a response voltage wave group.

[0135] In addition, by providing a third output buffer 93, the state of the third output buffer 93 can be adjusted to switch the third transducer 33 between different operating conditions, thereby realizing different functions. Specifically, when the third output buffer 93 is configured to the output state, the third output buffer 93 can provide an excitation voltage and current to the third transducer 33. At this time, the third transducer 33 acts as an excitation transducer, and the third transducer 33 generates and emits a group of acoustic waves; when the third output buffer 93 is configured to the cut-off state, the third output buffer 93 stops providing the excitation voltage and current to the third transducer 33. At this time, the third transducer 33 acts as a response transducer, and when the third transducer 33 receives the group of acoustic waves, a group of response voltage waves is generated. That is, by setting the state of the third output buffer 93, the third transducer 33 can emit a group of acoustic waves and can also receive a group of acoustic waves. Thus, the emission and reception of a group of acoustic waves can be realized by a single transducer, which is beneficial to cost reduction.

[0136] Among them, ranging can be performed by the acoustic wave flight time measurement device according to the embodiments of the present application. In a specific application, the third output buffer 93 can first be configured to the drive state, that is, the third output buffer 93 provides an excitation voltage and current to the third transducer 33, and the third transducer 33 emits a group of acoustic waves. Then, the third output buffer 93 is configured to the cut-off state. After the group of acoustic waves collides with an obstacle, it will be blocked, causing the group of acoustic waves to be reflected to the third transducer 33. The third transducer 33 can then receive the group of acoustic waves and generate a group of response voltage waves. In the present application, the flight time of the acoustic wave can be more accurately determined, and thus the distance between the acoustic wave flight time measurement device and the obstacle can be more accurately determined.

[0137] In addition, in some embodiments, the acoustic wave flight time measurement device may further include a reference voltage generation unit 80. The reference voltage generation unit 80 is electrically connected to the comparator 50, and the reference voltage generation unit 80 is configured to transmit a reference voltage to the comparator 50.

[0138] By setting the reference voltage generation unit 80, the control module 10 can control the reference voltage generation unit 80 to provide a comparison reference voltage to the comparator 50. The comparator 50 has a comparison reference terminal, and the reference voltage generation unit 80 can be electrically connected to the comparison reference terminal. Once the reference voltage generation unit 80 generates a comparison reference voltage, the comparison reference voltage can be transmitted to the comparison reference terminal. During the process that the signal voltage input to the input signal terminal of the comparator 50 changes from being less than the voltage of the comparison reference terminal to being greater than the voltage of the comparison reference terminal and then changes from being greater than the voltage of the comparison reference terminal to being less than the voltage of the comparison reference terminal, the comparator 50 will output a comparison pulse. That is, by setting the reference voltage generation unit 80, it is convenient for the comparator 50 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.

[0139] It should be noted that when the reference voltage generation unit 80 provides a comparison reference voltage that is not equal to the zero-crossing voltage value to the comparator 50, the comparator 50 will perform a non-zero comparison on the response voltage wave group. When the peak value of the response voltage wave is higher than the non-zero comparison reference voltage, the comparator outputs a non-zero comparison pulse; when the reference voltage generation unit 80 provides a comparison reference voltage equal to the zero-crossing voltage value to the comparator 50, the comparator 50 will perform a zero-crossing comparison on the response voltage wave group. When the peak value of the response voltage wave is higher than the zero-crossing comparison reference voltage, the comparator outputs a zero-crossing comparison pulse. Among them, the response voltage wave is usually a sine wave or a quasi-sine wave. The sine wave has a positive half-wave period and a negative half-wave period, and the zero-crossing voltage value is the voltage value corresponding to the switching point between the positive half-wave period and the negative half-wave period of the response voltage wave in the response voltage wave group. In addition, the comparison reference voltage provided by the reference voltage generation unit 80 to the comparator 50 that is not equal to the zero-crossing voltage value is called a non-zero comparison reference voltage. The non-zero comparison reference voltage can be a comparison reference voltage greater than the zero-crossing voltage value. Of course, it can also be a comparison reference voltage less than the zero-crossing voltage value, which can be specifically set according to actual needs. In this application, a non-zero comparison reference voltage greater than the zero-crossing voltage value is used to illustrate the basic principle and method of this application. For the voltage value of the non-zero comparison reference voltage, this application does not make specific limitations, and it is determined by those skilled in the art according to actual needs.

[0140] In addition, in some embodiments, the acoustic wave flight time measurement device may further include a pulse counting unit 60; the pulse counting unit 60 is electrically connected to the control module 10 and the comparator 50 respectively. The pulse counting unit 60 is used to count the number of non-zero comparison pulse signals transmitted to the pulse counting unit 60 and transmit the counted number of non-zero comparison pulse signals to the control module 10.

[0141] By setting up the pulse counting unit 60, the pulse counting unit 60 can transfer the counted number of non-zero comparison pulses to the control module 10. Thus, the control module 10 can determine whether the reference comparison voltage provided by the reference voltage generating unit 80 to the comparator 50 is appropriate, whether the current excitation response wave group measurement overflows, and whether the span time measurement module should stop measuring based on the number of non-zero comparison pulses transferred by the pulse counting unit 60 and the number of initial pulses emitted by the pulse generating unit 20.

[0142] In addition, in some embodiments, the acoustic wave transit time measurement device may further include a first coupling capacitor 101 and a second coupling capacitor 102. The transducer assembly 30 includes a first transducer 31 and a second transducer 32. The first coupling capacitor 101 is electrically connected to the first transducer 31, and the second coupling capacitor 102 is electrically connected to the second transducer 32. When the first transducer 31 serves as the response transducer, the first coupling capacitor 101 is used to couple the response voltage of the first transducer 31 to the comparator 50. When the second transducer 32 serves as the response transducer, the second coupling capacitor 102 is used to couple the response voltage of the second transducer 32 to the comparator 50.

[0143] By setting up the first coupling capacitor 101 and the second coupling capacitor 102, according to actual needs, when the first transducer 31 serves as the response transducer, the first coupling capacitor 101 can play a role. When the second transducer 32 serves as the response transducer, the second coupling capacitor 102 can play a role. Thus, the response voltage wave generated by the response transducer can be coupled to the comparator 50, facilitating the comparator 50 to make a comparison and simplifying the circuit design of the comparator 50. In addition, by setting up the first transducer 31 and the second transducer 32, distance measurement can be performed through the acoustic wave transit time measurement device. When the acoustic wave transit time measurement device includes a measurement tube 110, parameters such as the flow rate and flow volume of the fluid in the measurement tube 110 can also be measured.

[0144] In addition, in some embodiments, the acoustic wave transit time measurement device may further include a third coupling capacitor 103. The transducer assembly 30 includes a third transducer 33. The third coupling capacitor 103 is electrically connected to the third transducer 33. When the third transducer 33 serves as the response transducer, the third coupling capacitor 103 is used to couple the response voltage of the third transducer 33 to the comparator 50. By setting up the third transducer 33, distance measurement can be performed through the acoustic wave transit time measurement device.

[0145] In addition, in the embodiments of the present application, the control module 10 may include, but is not limited to, a central processing unit, a host computer, and a local control unit inside the span time measurement unit 40. Any component with control and operation functions can be used as the control module 10. For example, the control module 10 may be a chip with control functions. For another example, the control module 10 may be a circuit board with control functions. For yet another example, the control module 10 may be the local control unit inside the span time measurement unit 40, or it may be a combination of a central processing unit / host computer and a local control unit. In this regard, the embodiments of the present application do not make any limitations here.

[0146] In addition, in the embodiments of the present application, as Figure 1 shown, the control module 10 may include a host computer 11 and an integrated control unit 12. In some embodiments, a local control and operation unit is provided inside the span time measurement unit 40. At this time, the span time measurement unit 40 also has control and operation capabilities. At this time, the control module 10 also includes the local control and operation unit inside the span time measurement unit 40.

[0147] The embodiments of the present application provide a method for measuring the acoustic wave span time, which is applied to the acoustic wave flight time measurement device in any of the above embodiments. As Figure 7 shown, the measurement method includes:

[0148] Step 701: Obtain a first measurement value and a second measurement value of the span time measurement unit. The first measurement value includes the leading-edge reference span time count value of the non-zero comparison pulse, and the second measurement value includes the trailing-edge reference span time count value of the non-zero comparison pulse.

[0149] The control module is electrically connected to the span time measurement unit, so that the control module can obtain the measurement values of the span time measurement unit, that is, obtain the leading-edge reference span time count value and the trailing-edge reference span time count value measured by the span time measurement unit.

[0150] Among them, through the measurement of a group of response voltage waves, the span time measurement unit measures the count value of the reference span time of the leading edge and the trailing edge of the non-zero comparison pulse signal of the group of response voltage waves relative to the target edge of the selected pulse signal in the initial pulse group. That is, the span time measurement unit measures and samples the count values of the reference span time of both the leading edge and the trailing edge of the non-zero comparison pulse signal, so that the control module can obtain the first measurement value and the second measurement value simultaneously through the measurement of a group of response voltage waves. Of course, it is also possible to measure a group of response voltage waves twice. Each time, the span time measurement unit only measures the count value of the reference span time of one of the leading edge and the trailing edge of the non-zero comparison pulse signal relative to the target edge of the selected pulse signal in the initial pulse group. That is, in one measurement of a group of response voltage waves, the span time measurement unit only measures and samples the count value of the reference span time of either the leading edge or the trailing edge of the non-zero comparison pulse signal, and only measures the measurement value of the leading edge or the trailing edge each time, so that the control module first obtains one of the first measurement value and the second measurement value, and then obtains the other. Finally, through the measurement of a group of response voltage waves twice, the control module can obtain the first measurement value and the second measurement value.

[0151] Step 702: Determine the leading edge reference span time of the non-zero comparison pulse based on the first measurement value, and use it as the first reference span time, and determine the trailing edge reference span time of the non-zero comparison pulse based on the second measurement value, and use it as the second reference span time.

[0152] Among them, once the control module obtains the first measurement value, it can determine the leading edge reference span time of the non-zero comparison pulse according to the first measurement value. Specifically, the control module can multiply the first measurement value by the counting time resolution of its span time measurement unit to obtain the leading edge reference span time of the non-zero comparison pulse. In addition, once the control module obtains the second measurement value, it can determine the trailing edge reference span time of the non-zero comparison pulse according to the second measurement value. Specifically, the control module can multiply the second measurement value by the counting time resolution of its span time measurement unit to obtain the trailing edge reference span time of the non-zero comparison pulse.

[0153] Step 703: Determine whether the response voltage wave decays based on the first reference span time and / or the second reference span time.

[0154] Once the control module determines the first reference span time and the second reference span time, the control module can determine whether the response voltage wave decays based on the first reference span time and / or the second reference span time.

[0155] In some implementations, the implementation of step 703 can be as follows: determine N consecutive first reference span times, where the N first reference span times are sorted in sequence by time, and N is a positive integer greater than or equal to 2; determine the difference between any two adjacent first reference span times among the N first reference span times to obtain at least one first difference, and the first difference is: the difference between the second first reference span time and the first first reference span time among two adjacent first reference span times; sequentially determine the difference between at least one first difference and the pulse period of the initial pulse train to obtain the corresponding at least one first target difference; based on the at least one first target difference, determine whether the response voltage wave decays.

[0156] For example, determine 3 consecutive first reference span times, where the 3 first reference span times are sorted in sequence by time, and then determine the difference between any two adjacent first reference span times among the 3 first reference span times, and 2 first differences can be obtained. That is, subtract the first first reference span time from the second first reference span time to obtain 1 first difference, and subtract the second first reference span time from the third first reference span time to obtain 1 first difference. Then sequentially determine the difference between the 2 first differences and the initial pulse period to obtain 2 first target differences. That is, subtract the initial pulse period from the first first difference among the 2 first differences to obtain 1 first target difference, and subtract the initial pulse period from the second first difference among the 2 first differences to obtain 1 first target difference. Then, based on the 2 first target differences, determine whether the response voltage wave decays.

[0157] For example, determine 2 consecutive first reference span times, where the 2 first reference span times are sorted in sequence by time, and then determine the difference between the 2 first reference span times, and 1 first difference can be obtained. That is, subtract the first first reference span time from the second first reference span time to obtain 1 first difference. Then determine the difference between the 1 first difference and the initial pulse period to obtain 1 first target difference. That is, subtract the initial pulse period from the 1 first difference to obtain 1 first target difference. Then, based on the 1 first target difference, determine whether the response voltage wave decays.

[0158] In addition, in some implementations, the implementation of determining whether the response voltage wave decays based on at least one first target difference can be as follows: determine whether there is a first target difference greater than or equal to the first preset difference threshold among the at least one first target difference; if there is a first target difference greater than or equal to the first preset difference threshold among the at least one first target difference, then determine that the response voltage wave group decays.

[0159] For example, if two consecutive first target differences are determined to be 0 ns and 17 ns in sequence, and the first preset difference threshold is 5 ns. Among the two consecutive first target differences, the second first target difference of 17 ns is greater than 5 ns. That is, there is a first target difference greater than the first preset difference threshold in the first target differences, and it can be determined that the response voltage wave group has attenuation. Among them, in the specific judgment process, it can be judged whether the absolute value of the first first target difference in the two consecutive first target differences is less than a smaller preset threshold. If the absolute value of the first first target difference is less than a smaller preset threshold, it can be determined that the response voltage wave resonates and attenuates after resonance. The smaller preset threshold can be a positive value close to 0. For example, the smaller preset threshold is 0.5, or for another example, the smaller preset threshold is 0.1.

[0160] For example, if one first target difference is determined to be 17 ns and the first preset difference threshold is 5 ns, and the first target difference of 17 ns is greater than the first preset difference threshold of 5 ns. That is, there is a first target difference greater than or equal to the first preset difference threshold in the first target differences, then it is determined that the response voltage wave group has attenuation.

[0161] It should be noted that the first preset difference threshold is set according to actual needs, and the specific value of the first preset difference threshold is not limited in the embodiments of the present application.

[0162] In addition, in the embodiments of the present application, if there is no first target value greater than or equal to the first preset difference threshold among multiple first target differences, that is, multiple first target differences are all less than the first preset difference threshold, then it is determined that the response voltage wave group does not have attenuation.

[0163] In some implementation manners, the implementation manner of step 703 can be: determine N consecutive second reference span times, and the N second reference span times are sorted in sequence according to time; determine the differences between any two adjacent second reference span times among the N second reference span times to obtain at least one second difference, and the second difference is: the difference between the second second reference span time and the first second reference span time among two adjacent second reference span times; sequentially determine the differences between at least one second difference and the pulse period of the initial pulse group to obtain corresponding at least one second target difference; based on at least one second target difference, determine whether the response voltage wave attenuates.

[0164] For example, determine three consecutive second reference span times, and sort the three second reference span times in sequence according to time. Then, determine the difference between any two adjacent second reference span times among the three second reference span times, and two second differences can be obtained. That is, subtract the first second reference span time from the second second reference span time to obtain one second difference, and subtract the second second reference span time from the third second reference span time to obtain one second difference. Then, determine the differences between the two second differences and the initial pulse period in sequence to obtain two second target differences. That is, subtract the initial pulse period from the first second difference among the two second differences to obtain one second target difference, and subtract the initial pulse period from the second second difference among the two second differences to obtain one second target difference. Then, based on the two second target differences, determine whether the response voltage wave decays.

[0165] For example, determine two consecutive second reference span times, and sort the two second reference span times in sequence according to time. Then, determine the difference between the two second reference span times, and one second difference can be obtained. That is, subtract the first second reference span time from the second second reference span time to obtain one second difference. Then, determine the difference between the one second difference and the initial pulse period to obtain one second target difference. That is, subtract the initial pulse period from the one second difference to obtain one second target difference. Then, based on the one second target difference, determine whether the response voltage wave decays.

[0166] In addition, in some implementation manners, determining whether the response voltage wave decays based on at least one second target difference includes: determining whether there is a second target difference less than a second preset difference threshold among the at least one second target difference; if there is a second target difference less than the second preset difference threshold among the at least one second target difference, then determine that the response voltage wave group decays.

[0167] For example, it is determined that two consecutive second target differences are 0ns and -17ns in sequence, the second preset difference threshold is -5ns, and the second second target difference -17ns among the two consecutive second target differences is less than the second preset difference threshold -5ns, that is, there is a second target difference less than the second preset difference threshold among the second target differences, then it is determined that the response voltage wave group decays. Among them, in the specific judgment process, it can also be judged whether the absolute value of the first second target difference among the two consecutive second target differences is less than a smaller preset threshold. If the absolute value of the first second target difference is less than a smaller preset threshold, then it can be determined that the response voltage wave resonates and decays after resonance. Among them, the smaller preset threshold can be a positive value close to 0. For example, the smaller preset threshold is 0.5, and for another example, the smaller preset threshold is 0.1.

[0168] For example, if it is determined that one second target difference is -17 ns, the second preset difference threshold is -5 ns, and the one second target difference of -17 ns is less than the second preset difference threshold of -5 ns, that is, there is a second target difference in the second target differences that is less than the second preset difference threshold, then it is determined that the response voltage wave group has attenuation.

[0169] It should be noted that the second preset difference threshold is set according to actual needs, and the specific value of the second preset difference threshold is not limited in this embodiment of the present application. Among them, the second preset difference threshold can be a negative value.

[0170] In addition, in this embodiment of the present application, if there is no second target value in the multiple second target differences that is less than the second preset difference threshold, that is, the multiple second target differences are all greater than or equal to the second preset difference threshold, then it is determined that the response voltage wave group has not attenuated.

[0171] In some implementation manners, the implementation manner of step 703 may be: determining N consecutive first reference span times, and the N consecutive first reference span times are sorted in sequence according to time; determining the differences between any two adjacent first reference span times among the N consecutive first reference span times to obtain a plurality of first differences, and the first difference is: the difference between the second first reference span time and the first first reference span time in two adjacent first reference span times; determining the differences between the second first difference and the first first difference among any two adjacent first differences in the plurality of first differences to obtain corresponding third target differences; and determining whether the response voltage wave attenuates based on the plurality of third target differences.

[0172] For example, if it is determined that there are 4 consecutive first reference span times, and the 4 consecutive first reference span times are sorted in sequence according to time, and then the differences between any two adjacent first reference span times among the 4 consecutive first reference span times are determined, 3 consecutive first differences can be obtained. That is, subtracting the first first reference span time from the second first reference span time to obtain one first difference, subtracting the second first reference span time from the third first reference span time to obtain one first difference, and subtracting the third first reference span time from the fourth first reference span time to obtain one first difference. Then, the differences between the second first difference and the first first difference among any two adjacent first differences in the 3 consecutive first differences are determined, and 2 consecutive third target differences can be obtained. That is, subtracting the first first difference from the second first difference to obtain one third target difference, and subtracting the second first difference from the third first difference to obtain one third target difference, that is, 2 third target differences are obtained. Then, it is determined whether the response voltage wave attenuates based on the 2 consecutive third target differences.

[0173] In addition, in some implementation manners, the implementation manner of determining whether the response voltage wave attenuates based on multiple third target differences may be: determining whether the absolute value of the first third target difference is less than a third preset difference threshold and whether the second third target difference is greater than or equal to a fourth preset difference threshold among two consecutive third target differences; if, among two consecutive third target differences, the absolute value of the first third target difference is less than the third preset difference threshold and the second third target difference is greater than or equal to the fourth preset difference threshold, it is determined that the response voltage wave group attenuates.

[0174] For example, determine two consecutive third target differences. The two consecutive third target differences are 0 ns and 17 ns in sequence. Set the third preset difference threshold to 1 ns and set the fourth preset difference threshold to 5 ns; among the two consecutive third target differences, the absolute value of the first third target difference of 0 ns is less than the third preset difference threshold of 1 ns, and the second third target difference of 17 ns is greater than the fourth preset difference threshold of 5 ns, then it is determined that the response voltage wave group attenuates. Among them, in the specific judgment process, it can be judged whether the absolute value of the first third target difference among two consecutive third target differences is less than a smaller preset threshold. If the absolute value of the first third target difference is less than a smaller preset threshold, it can be determined that the response voltage wave resonates and attenuates after resonance. Among them, the smaller preset threshold can be a positive value close to 0. For example, the smaller preset threshold is 0.5, and for another example, the smaller preset threshold is 0.1.

[0175] It should be noted that the third preset difference threshold and the fourth preset difference threshold are set according to actual needs, and the specific values of the third preset difference threshold and the fourth preset difference threshold are not limited in this embodiment of the present application.

[0176] In addition, in the embodiment of the present application, among two consecutive third target differences, if the absolute value of the first third target difference is greater than or equal to the third preset difference threshold, it is determined that the response voltage wave group does not attenuate; or, among two consecutive third target differences, if the absolute value of the first third target difference is less than the third preset difference threshold and the second third target difference is less than the fourth preset difference threshold, it is determined that the response voltage wave group does not attenuate; or, among two consecutive third target differences, if the absolute value of the first third target difference is greater than or equal to the third preset difference threshold and the second third target difference is less than the fourth preset difference threshold, it is determined that the response voltage wave group does not attenuate.

[0177] In some implementations, the implementation of step 703 can be as follows: determine N consecutive second reference span times, where the N second reference span times are sorted in sequence according to time; determine the difference between any two adjacent second reference span times among the N second reference span times to obtain a plurality of second differences, and the second difference is: the difference between the second second reference span time and the first second reference span time among two adjacent second reference span times; determine the difference between the second second difference and the first second difference among two adjacent second differences in the plurality of second differences to obtain corresponding plurality of fourth target differences; based on the plurality of fourth target differences, determine whether the response voltage wave decays.

[0178] For example, determine 4 consecutive second reference span times, where the 4 second reference span times are sorted in sequence according to time, and then determine the difference between any two adjacent second reference span times among the 4 second reference span times, so that 3 consecutive second differences can be obtained. That is, subtract the first second reference span time from the second second reference span time to obtain 1 second difference, subtract the second second reference span time from the third second reference span time to obtain 1 second difference, and subtract the third second reference span time from the fourth second reference span time to obtain 1 second difference. Then determine the difference between the second second difference and the first second difference among 3 consecutive second differences to obtain corresponding 2 consecutive fourth target differences. That is, subtract the first second difference from the second second difference to obtain 1 fourth target difference, subtract the second second difference from the third second difference to obtain 1 fourth target difference, that is, obtain 2 consecutive fourth target differences. Then, based on the 2 consecutive fourth target differences, determine whether the response voltage wave decays.

[0179] In addition, in some implementations, the implementation of determining whether the response voltage wave decays based on the plurality of fourth target differences can be as follows: determine whether the absolute value of the first fourth target difference is less than a fifth preset difference threshold and whether the second fourth target difference is less than a sixth preset difference threshold among two consecutive fourth target differences; if among two consecutive fourth target differences, the absolute value of the first fourth target difference is less than the fifth preset difference threshold and the second fourth target difference is less than the sixth preset difference threshold, then determine that the response voltage wave group decays.

[0180] For example, determine two consecutive fourth target differences. The two consecutive fourth target differences are 0 ns and -17 ns in sequence. Set the fifth preset difference threshold to 1 ns and the sixth preset difference threshold to -5 ns. Among the two consecutive fourth target differences, the absolute value of the first fourth target difference, 0 ns, is less than the fifth preset difference threshold of 1 ns, and the second fourth target difference, -17 n, is less than the sixth preset difference threshold of -5 ns. Then it is determined that the response voltage wave group has attenuation. Among them, in the specific judgment process, it can be judged whether the absolute value of the first fourth target difference in the two consecutive fourth target differences is less than a smaller preset threshold. If the absolute value of the first fourth target difference is less than a smaller preset threshold, it can be determined that the response voltage wave resonates and attenuates after resonance. The smaller preset threshold can be a positive value close to 0. For example, the smaller preset threshold is 0.5, or for another example, the smaller preset threshold is 0.1.

[0181] It should be noted that the fifth preset difference threshold and the sixth preset difference threshold are set according to actual needs, and the specific values of the fifth preset difference threshold and the sixth preset difference threshold are not limited in the embodiments of the present application. Among them, the fifth preset difference threshold can be a positive value, and the sixth preset difference threshold can be a negative value.

[0182] In addition, in the embodiments of the present application, among the two consecutive fourth target differences, if the absolute value of the first fourth target difference is greater than or equal to the fifth preset difference threshold, it is determined that the response voltage wave group does not have attenuation; or, among the two consecutive fourth target differences, if the absolute value of the first fourth target difference is less than the fifth preset difference threshold and the second fourth target difference is greater than or equal to the sixth preset difference threshold, it is determined that the response voltage wave group does not have attenuation; or, among the two consecutive fourth target differences, if the absolute value of the first fourth target difference is greater than or equal to the fifth preset difference threshold and the second fourth target difference is greater than or equal to the sixth preset difference threshold, it is determined that the response voltage wave group does not have attenuation.

[0183] In some implementation manners, the implementation manner of step 703 can be: determine the difference between the second reference span time and the first reference span time as the first time difference; determine N consecutive first time differences, and the N first time differences are sorted in sequence according to time; determine the difference between the second first time difference and the first time difference among any two adjacent first time differences in the N first time differences to obtain at least one corresponding fifth target difference; based on the at least one fifth target difference, determine whether the response voltage wave group attenuates.

[0184] Among them, each pulse has a leading edge and a trailing edge. The second reference span time is obtained according to the trailing edge reference span time count value, that is, the second reference span time can represent the time at which the trailing edge of each pulse is located. The first reference span time is obtained according to the leading edge reference span time count value, that is, the first reference span time can represent the time at which the leading edge of each pulse is located. Determine the difference between the second first time difference and the first first time difference among any two adjacent first time differences in the N first time differences, so as to obtain corresponding multiple fifth target differences, that is, the fifth target difference can represent the span time from the trailing edge to the leading edge of the pulse.

[0185] For example, if it is determined that three consecutive first time differences are 400ns, 400ns, and 367ns in sequence, and the three consecutive first time differences are sorted in chronological order, and then the differences between any two adjacent first time differences among the three consecutive first time differences are determined, 2 fifth target differences can be obtained, that is, subtract the second first time difference from the first first time difference to obtain 1 fifth target difference, and subtract the third first time difference from the second first time difference to obtain 1 fifth target difference. Then, it is possible to determine whether the response voltage wave group decays according to the 2 fifth target differences.

[0186] In some implementation manners, the implementation manner of determining whether the response voltage wave group decays based on at least one fifth target difference may be: if there is a fifth target difference less than the seventh preset difference threshold among at least one fifth target difference, it is determined that the response voltage wave group decays. Among them, if there is a fifth target difference less than the seventh preset difference threshold among at least one fifth target difference, it indicates that the span time from the trailing edge to the leading edge of the pulse begins to decrease, and it is determined that the response voltage wave group decays.

[0187] For example, set the seventh preset difference threshold to -5ns. It is determined that two consecutive first time differences are 400ns and 367ns in sequence, and the two consecutive first time differences are sorted in chronological order, and then the difference between the two first time differences is determined, and 1 fifth target difference can be obtained, that is, subtract the second first time difference from the first first time difference to obtain 1 fifth target difference of -33ns; the fifth target difference of -33ns is less than the seventh preset difference threshold of -5ns, that is, there is a fifth target difference less than the seventh preset difference threshold among the fifth target differences, indicating that the width of the pulse begins to decrease, and it is determined that the response voltage wave group decays.

[0188] In some implementations, the implementation of determining whether the response voltage wave group decays based on at least one fifth target difference may be: If, among two consecutive fifth target differences, the absolute value of the first fifth target difference is less than the eighth preset difference threshold, and the second fifth target difference is less than the seventh preset difference threshold, it is determined that the response voltage wave group decays.

[0189] For example, set the seventh preset difference threshold to -5 ns and the eighth preset difference threshold to 1 ns. The two consecutive fifth target differences are 0 ns and -33 ns in sequence; among the two consecutive fifth target differences, the absolute value of the first fifth target difference, 0 ns, is less than the eighth preset difference threshold of 1 ns, and the second fifth target difference, -33 ns, is less than the seventh preset difference threshold of -5 ns. That is, there is a fifth target difference among the fifth target differences that is less than the seventh preset difference threshold, indicating that the span time from the trailing edge to the leading edge of the pulse begins to decrease, so it is determined that the response voltage wave group decays. Moreover, since the absolute value of the first fifth target difference, 0 ns, is less than the eighth preset difference threshold of 1 ns, it can also be determined that the response voltage wave resonates and decays after resonance. Among them, in the specific judgment process, it can be determined whether the absolute value of the first fifth target difference in two consecutive fifth target differences is less than a smaller preset threshold. If the absolute value of the first fifth target difference is less than a smaller preset threshold, it can be determined that the response voltage wave resonates and decays after resonance. The smaller preset threshold can be a positive value close to 0. For example, the smaller preset threshold is 0.5, or for another example, the smaller preset threshold is 0.1.

[0190] Step 704: When the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold, stop measuring the acoustic flight time of the acoustic wave group, and determine the acoustic flight time of the acoustic wave group based on the first reference span time and the second reference span time.

[0191] Among them, once the attenuation amount of the response voltage wave is greater than or equal to the preset attenuation threshold, it indicates that the initial pulse group has stopped emitting, the last acoustic wave of the acoustic wave group excited by the excitation transducer has reached the receiving transducer, and the receiving transducer has completed the response and started to decay. Thus, the measurement of the acoustic flight time of the acoustic wave group is stopped, and then the acoustic flight time of the acoustic wave group can be determined based on the reference span time of the non-zero comparison pulse, that is, the acoustic flight time of the acoustic wave group is determined based on the first reference span time and the second reference span time.

[0192] In addition, in some implementation manners, the implementation manner of determining the acoustic wave transit time of the acoustic wave group based on the first reference span time and the second reference span time may be: adding the first reference span time and the second reference span time to obtain a first time value, and determining a time value that is half of the first time value, so as to obtain a second time value; determining the acoustic wave transit time according to the second time value and the pulse period of the initial pulse group.

[0193] Among them, the second time value is equivalent to the time value representing the position of the middle time point of the pulse, that is, it is equivalent to determining the time value at the position of the middle time point of the non-zero comparison pulse; then the acoustic wave transit time can be determined according to the second time value and the pulse period of the initial pulse group.

[0194] For example, if the first reference span time is 21050 ns and the second reference span time is 21080 ns, then the first time value obtained is 42130 ns, and half of the first time value is 21065 ns, that is, the second time value is 21065 ns.

[0195] In addition, in some implementation manners, the implementation manner of determining the acoustic wave transit time according to the second time value and the pulse period of the initial pulse group may be: determining the sum of the second time value and one-fourth of the pulse period of the initial pulse group to obtain a third time value; determining the acoustic wave transit time according to the third time value.

[0196] Among them, determining the sum of the second time value and one-fourth of the pulse period of the initial pulse group is equivalent to using the time value at the position of the middle time point of the non-zero comparison pulse to determine the reference span time of the trailing edge of the zero-crossing comparison pulse. This is because in this application, the comparator does not perform zero-crossing comparison, and the comparator only performs non-zero comparison, so only non-zero comparison pulses are obtained. By using the non-zero comparison pulses, the reference span time of the trailing edge of the virtual zero-crossing comparison pulse is determined, so as to accurately determine the acoustic wave transit time.

[0197] In addition, in some implementation manners, the implementation manner of determining the acoustic wave transit time according to the second time value and the pulse period of the initial pulse group may be: determining the difference between the second time value and one-fourth of the pulse period of the initial pulse group to obtain a fourth time value; determining the acoustic wave transit time according to the fourth time value.

[0198] Among them, determining the difference between the second time value and one-fourth of the pulse period of the initial pulse group is equivalent to using the time value at the position of the middle time point of the non-zero comparison pulse to determine the reference span time of the leading edge of the zero-crossing comparison pulse. This is because in this application, the comparator does not perform zero-crossing comparison, and the comparator only performs non-zero comparison, so only non-zero comparison pulses are obtained. By using the non-zero comparison pulses, the reference span time of the leading edge of the virtual zero-crossing comparison pulse is determined, so as to accurately determine the acoustic wave transit time.

[0199] It should be noted that in the embodiments of the present application, for the comparison with the threshold, it is determined by being greater than or equal to the threshold and less than the threshold, which clarifies the principle of the present application. Of course, for the comparison with the threshold, it can also be determined by being greater than the threshold and less than or equal to the threshold, or by being greater than the threshold and less than the threshold. In this regard, the embodiments of the present application do not make any limitations. For example, in two consecutive third target differences, if the absolute value of the first third target difference is less than the third preset difference threshold, and the second third target difference is greater than or equal to the fourth preset difference threshold, it is determined that the response voltage wave group has attenuation. It can also be determined that the response voltage wave group has attenuation when, in two consecutive third target differences, the absolute value of the first third target difference is less than or equal to the third preset difference threshold, and the second third target difference is greater than the fourth preset difference threshold.

[0200] In addition, in the embodiments of the present application, the non-zero comparison pulse can be a positive pulse or a negative pulse. In the present application, the basic principle and method are described with the non-zero comparison pulse being a positive pulse. When the non-zero comparison pulse is a negative pulse, those skilled in the art can refer to the basic principle and method described in the present application to design and adjust the corresponding threshold and the way and direction of threshold judgment to achieve the measurement of the effective acoustic flight time. That is, whether the non-zero comparison pulse is a positive pulse or a negative pulse, the basic principle and method provided by the present application can be used to determine the effective acoustic flight time.

[0201] The embodiments of the present application provide a device, which includes the device for measuring the acoustic flight time in any one of the above embodiments.

[0202] It should be noted that the devices in the embodiments of the present application include but are not limited to vehicles, ships, submarines, water meters, heat meters, gas meters, oil meters, flow meters, etc.

[0203] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0204] Although embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. 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 device for measuring the acoustic wave flight time comprises: a control module, a pulse generating unit, a transducer assembly, a span time measuring unit and a comparator; The span time measurement unit and the pulse generation unit are both electrically connected to the control module; the pulse generation unit is electrically connected to the transducer assembly and the span time measurement unit respectively, the transducer assembly is electrically connected to the comparator, the comparator is electrically connected to the span time measurement unit, and the transducer assembly is used to generate and transmit a sound wave group, and / or receive a sound wave group; The pulse generating unit is used to generate and output a periodic initial pulse group, the transducer assembly is used to generate and transmit an acoustic wave group, and the transducer assembly 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 comparator; The comparator is used for performing non-zero comparison on the response voltage wave group to output a non-zero comparison pulse signal, and transmitting the non-zero comparison pulse signal to the span time measurement unit; The span time measurement unit is used to measure the count value of the reference span time of the leading edge and the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the pulse signal selected in the initial pulse group, so as to obtain the count value of the leading edge reference span time and the count value of the trailing edge reference span time; The control module is used to determine the corresponding leading edge reference span time and trailing edge reference span time according to the leading edge reference span time count value and the trailing edge reference span time count value, and determine whether the response voltage wave is attenuated according to the leading edge reference span time and / or the trailing edge reference span time, and when the attenuation of the response voltage wave is greater than or equal to a preset attenuation threshold, stop measuring the sound wave transit time of the sound wave group, and determine the sound wave transit time of the sound wave group based on the leading edge reference span time and the trailing edge reference span time.

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 pulse counting unit; The pulse counting unit is electrically connected to the control module and the comparator respectively, and is used to count the number of non-zero comparison pulse signals transmitted to the pulse counting unit, and transmit the counted number of non-zero comparison pulse signals to the control module.

3. The device for measuring the acoustic wave transit time according to claim 1, characterized in that: The span time measurement unit includes a first span measurement subunit and a second span measurement subunit; The pulse generating unit is electrically connected to the first span measuring subunit and the second span measuring subunit respectively; The first span measurement subunit is used to measure the count value of the reference span time of the leading edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the pulse signal selected in the initial pulse group to obtain the leading edge reference span time count value; The second span measurement subunit is used to measure the count value of the reference span time of the trailing edge of the non-zero comparison pulse signal of the response voltage wave group relative to the target edge of the pulse signal selected in the initial pulse group to obtain the trailing edge reference span time count value.

4. 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 to 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, the second transducer receives the sound wave group and generates a response voltage wave group, and the response transducer is electrically connected to the comparator. 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 to 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, the first transducer receives the sound wave group and generates a response voltage wave group, and the response transducer is electrically connected to the comparator.

5. The device for measuring the acoustic wave transit time according to claim 4, characterized in that: The device for measuring the acoustic wave transit time also includes a measuring tube; One of the first transducer and the second transducer is disposed at the first end of the measuring tube, and the other is disposed at the second end of the measuring tube.

6. 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 the transducer assembly comprises a third transducer; The third output buffer is electrically connected to the pulse generating unit and the third transducer respectively.

7. 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 reference voltage generating unit, wherein the reference voltage generating unit is electrically connected to the comparator and is used for transmitting a reference voltage to the comparator.

8. 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 is used as a response transducer, the first coupling capacitor is used to couple the response voltage of the first transducer to the comparator; when the second transducer is used as a response transducer, the second coupling capacitor is used to couple the response voltage of the second transducer to the comparator.

9. 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 coupling capacitor, and the transducer assembly comprises 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.

10. A method for measuring the span time of a sound wave, characterized in that: Applicable to the device for measuring the acoustic wave transit time as described in any one of claims 1 to 9, the measuring method comprises: Acquire a first measurement value and a second measurement value of the span time measurement unit, wherein the first measurement value includes a leading edge reference span time count value of a non-zero comparison pulse, and the second measurement value includes a trailing edge reference span time count value of a non-zero comparison pulse; Determine a leading edge reference span time of a non-zero comparison pulse based on the first measurement value and use it as a first reference span time, and determine a trailing edge reference span time of a non-zero comparison pulse based on the second measurement value and use it as a second reference span time; Determining whether the response voltage wave is attenuated based on the first reference span time and / or the second reference span time; When the attenuation of the response voltage wave is greater than or equal to a preset attenuation threshold, the measurement of the acoustic wave transit time of the acoustic wave group is stopped, and the acoustic wave transit time of the acoustic wave group is determined based on the first reference span time and the second reference span time.

11. The method for measuring the sound wave span time according to claim 10, characterized in that: The determining the acoustic wave transit time of the acoustic wave group based on the first reference span time and the second reference span time comprises: adding the first reference span time to the second reference span time to obtain a first time value, and determining a time value that is half of the first time value to obtain a second time value; The acoustic wave flight time is determined according to the second time value and the pulse period of the initial pulse group.

12. The method for measuring the sound wave span time according to claim 11, characterized in that: Determining the acoustic wave flight time according to the second time value and the pulse period of the initial pulse group includes: Determine the sum of the second time value and one quarter of the pulse period of the initial pulse group to obtain a third time value; The acoustic wave transit time is determined according to the third time value.

13. The method for measuring the sound wave span time according to claim 11, characterized in that: Determining the acoustic wave flight time according to the second time value and the pulse period of the initial pulse group includes: determining a difference between the second time value and one quarter of the pulse period of the initial pulse group to obtain a fourth time value; The acoustic wave flight time is determined according to the fourth time value.

14. The method for measuring the acoustic wave transit time according to claim 10, characterized in that: The step of determining whether the response voltage wave is attenuated based on the first reference span time and / or the second reference span time includes: Determine N consecutive first reference span times, where the N first reference span times are sorted in time sequence, and N is a positive integer greater than or equal to 2; Determine a difference between any two adjacent first reference span times among the N first reference span times to obtain at least one first difference, and the first difference is: a difference between the second first reference span time and the first first reference span time among the two adjacent first reference span times; sequentially determining a difference between at least one of the first difference values ​​and a pulse period of an initial pulse group to obtain at least one corresponding first target difference value; Based on at least one of the first target difference values, it is determined whether the response voltage wave is attenuated.

15. The method for measuring the acoustic wave transit time according to claim 14, characterized in that: The determining whether the response voltage wave is attenuated based on at least one of the first target difference values ​​comprises: Determine whether there is a first target difference greater than or equal to a first preset difference threshold among at least one of the first target differences; if there is a first target difference greater than or equal to the first preset difference threshold among at least one of the first target differences, determine that the response voltage wave group is attenuated.

16. The method for measuring the acoustic wave transit time according to claim 10, characterized in that: The step of determining whether the response voltage wave is attenuated based on the first reference span time and / or the second reference span time includes: Determine N consecutive second reference span times, where the N second reference span times are sequentially sorted according to time; Determine the difference between any two adjacent second reference span times among the N second reference span times to obtain at least one second difference, and the second difference is: the difference between the second second reference span time and the first second reference span time among the two adjacent second reference span times; sequentially determining the difference between at least one of the second difference values ​​and the pulse period of the initial pulse group to obtain at least one corresponding second target difference value; Based on at least one of the second target difference values, it is determined whether the response voltage wave is attenuated.

17. The method for measuring the acoustic wave transit time according to claim 16, characterized in that: The determining whether the response voltage wave is attenuated based on at least one of the second target differences comprises: Determine whether there is a second target difference value less than a second preset difference threshold value among at least one of the second target differences; if there is a second target difference value less than a second preset difference threshold value among at least one of the second target differences, determine that the response voltage wave group is attenuated.

18. The method for measuring the acoustic wave transit time according to claim 10, characterized in that: The step of determining whether the response voltage wave is attenuated based on the first reference span time and / or the second reference span time includes: Determine N consecutive first reference span times, where the N first reference span times are sorted in time sequence; Determine a difference between any two adjacent first reference span times among the N first reference span times to obtain a plurality of first difference values, wherein the first difference value is: a difference between the second first reference span time and the first first reference span time among the two adjacent first reference span times; Determine a difference between a second first difference and a first first difference of two adjacent first differences in the plurality of first differences to obtain a corresponding plurality of third target differences; Based on the plurality of the third target difference values, it is determined whether the response voltage wave is attenuated.

19. The method for measuring the acoustic wave transit time according to claim 18, characterized in that: The step of determining whether the response voltage wave is attenuated based on the plurality of third target differences comprises: Determine whether the absolute value of the first third target difference value is less than the third preset difference threshold value among two consecutive third target differences, and whether the second third target difference value is greater than or equal to the fourth preset difference threshold value; if, among two consecutive third target differences, the absolute value of the first third target difference value is less than the third preset difference threshold value, and the second third target difference value is greater than or equal to the fourth preset difference threshold value, then determine that the response voltage wave group is attenuated.

20. The method for measuring the acoustic wave transit time according to claim 10, characterized in that: The step of determining whether the response voltage wave is attenuated based on the first reference span time and / or the second reference span time includes: Determine N consecutive second reference span times, where the N second reference span times are sequentially sorted according to time; Determine a difference between any two adjacent second reference span times among the N second reference span times to obtain a plurality of second difference values, wherein the second difference value is: a difference between the second second reference span time and the first second reference span time among the two adjacent second reference span times; Determine a difference between a second second difference and a first second difference of two adjacent second differences in the plurality of second differences to obtain a corresponding plurality of fourth target differences; Based on the plurality of fourth target difference values, it is determined whether the response voltage wave is attenuated.

21. The method for measuring the acoustic wave transit time according to claim 20, characterized in that: The determining whether the response voltage wave is attenuated based on the plurality of fourth target differences comprises: Determine whether the absolute value of the first fourth target difference value is less than the fifth preset difference threshold value among two consecutive fourth target differences, and whether the second fourth target difference value is less than the sixth preset difference threshold value; if, among two consecutive fourth target differences, the absolute value of the first fourth target difference value is less than the fifth preset difference threshold value, and the second fourth target difference value is less than the sixth preset difference threshold value, then determine that the response voltage wave group is attenuated.

22. The method for measuring the sound wave span time according to claim 10, characterized in that: The step of determining whether the response voltage wave is attenuated based on the first reference span time and / or the second reference span time includes: Determine a difference between the second reference span time and the first reference span time as a first time difference; Determine N consecutive first time difference values, and the N first time difference values ​​are sorted in time sequence; Determine a difference between a second first time difference and the first time difference of any two adjacent first time differences among the N first time differences to obtain at least one corresponding fifth target difference; Based on at least one of the fifth target difference values, it is determined whether the response voltage wave group is attenuated.

23. The method for measuring the sound wave span time according to claim 22, characterized in that: The determining whether the response voltage wave group is attenuated based on at least one of the fifth target difference values ​​comprises: If a fifth target difference among at least one of the fifth target differences is smaller than a seventh preset difference threshold, it is determined that the response voltage wave group is attenuated.

24. The method for measuring the sound wave span time according to claim 22, characterized in that: The determining whether the response voltage wave group is attenuated based on at least one of the fifth target difference values ​​comprises: If, in two consecutive fifth target differences, the absolute value of the first fifth target difference is less than the eighth preset difference threshold, and the second fifth target difference is less than the seventh preset difference threshold, it is determined that the response voltage wave group is attenuated.

25. A device, characterized in that The device comprises the device for measuring the acoustic wave transit time according to any one of claims 1-9.

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