Flow velocity measuring device and method, control device and medium

Abstract

The invention discloses a flow velocity measuring device and method, a control device and a medium, and the device comprises an ultrasonic transmitting probe which is used for transmitting an ultrasonic signal; the ultrasonic receiving probe is used for receiving echo signals; different frequency mixers have different reference frequencies, each frequency mixer is used for outputting an absolute value of a frequency difference between the echo signal and the corresponding reference frequency, and the difference between any two reference frequencies is larger than twice of a preset minimum frequency and smaller than a difference value between a preset maximum frequency and the preset minimum frequency; the control device is used for obtaining all frequency difference absolute values, determining the size relation between the to-be-measured frequency of the echo signal and all reference frequencies according to all frequency difference absolute values, and calculating the to-be-measured frequency according to the size relation, the target frequency difference absolute value and the reference frequency corresponding to the target frequency difference absolute value. The target frequency difference absolute value is one of all the frequency difference absolute values greater than the preset minimum frequency and less than the preset maximum frequency. The method can improve the frequency measurement precision and reduce the time consumption.

Description

Technical Field

[0001] The present invention relates to the technical field related to flow velocity measurement, and in particular, to a flow velocity measurement device, method, control device and medium. Background Art

[0002] The existing method for measuring water flow velocity is to emit ultrasonic waves through ultrasonic probe A. After the ultrasonic waves encounter substances in water, reflected waves are formed, and the reflected waves are received by ultrasonic probe B. The flow velocity of water is calculated through the frequencies of the transmitted wave and the reflected wave. However, considering cost performance, the embedded chips we generally use are mid - to - low - end embedded chips. The frequency measurement of existing mid - to - low - end embedded chips can only be accurate to the microsecond level, and can only distinguish between 1MHz and 1.000001MHz, but cannot distinguish to 1.0000001MHz, so the measurement accuracy is insufficient. At the same time, if accurate measurement is required, it takes 1 second to measure accurately, which takes a long time. If the Fast Fourier Transform (FFT) method is used, the waveform needs to be sampled by an analog - to - digital conversion module and then Fourier - transformed to obtain a frequency value. Similarly, 1 second of sampling time is required to be accurate to 1Hz, and the calculation process is relatively complex and time - consuming. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a flow velocity measurement device, which can improve the frequency measurement accuracy and reduce the time consumption.

[0004] The present invention also provides a flow velocity measurement method, a control device for executing the above - mentioned flow velocity measurement method, and a computer - readable storage medium.

[0005] According to an embodiment of the first aspect of the present invention, the flow velocity measurement device includes: An ultrasonic transmitting probe, configured to transmit ultrasonic signals; An ultrasonic receiving probe, configured to receive an echo signal generated after the ultrasonic signal is reflected by an obstacle in water; At least two mixers, the input ends of which are respectively electrically connected to the ultrasonic receiving probe. Different mixers have different reference frequencies. Each mixer is configured to output the absolute value of the frequency difference between the echo signal and the corresponding reference frequency, wherein the difference between any two reference frequencies is greater than twice the preset minimum frequency and less than the difference between the preset maximum frequency and the preset minimum frequency; A control device is respectively connected to the output ends of all mixers. The control device is configured to obtain all absolute frequency differences, determine the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to all the absolute frequency differences, and calculate the frequency to be measured based on the magnitude relationship, the target absolute frequency difference, and the reference frequency corresponding to the target absolute frequency difference. Wherein, the target absolute frequency difference is one of all the absolute frequency differences that is greater than the preset minimum frequency and less than the preset maximum frequency.

[0006] The flow velocity measuring device according to the embodiment of the present invention has at least the following beneficial effects: By mixing the echo signal with at least two mixers, at least two absolute frequency differences between the frequency to be measured of the echo signal and the corresponding reference frequencies can be obtained. However, since the values obtained by the mixers are absolute values, the frequency to be measured cannot be directly calculated. According to all the absolute frequency differences, the magnitude relationship between the frequency to be measured and all the reference frequencies can be determined, so that the frequency to be measured can be calculated based on the target absolute frequency difference and the reference frequency corresponding to the target absolute frequency difference. Since the reliability of the measured value will be discounted when the output value of the mixer is less than the preset minimum frequency or greater than the preset maximum frequency, selecting one of all the absolute frequency differences that is greater than the preset minimum frequency and less than the preset maximum frequency for calculation can ensure the reliability of the calculation result. The frequency after mixing can be accurate to 1 Hz, which improves the frequency measurement accuracy compared with the existing frequency measurement of embedded chips, and there is no need to perform FFT analysis, saving time and calculation amount. The flow velocity measuring device according to the embodiment of the present invention can improve the frequency measurement accuracy and reduce the time consumption.

[0007] According to some embodiments of the present invention, the number of mixers is three.

[0008] According to some embodiments of the present invention, the echo signal is within a preset frequency range, and the preset frequency range is equally divided into four frequency intervals. The three reference frequencies corresponding to the three mixers are respectively the right boundary values of the first three frequency intervals.

[0009] According to some embodiments of the present invention, a signal amplification and filtering circuit is further provided between the ultrasonic receiving probe and each mixer, and a filtering circuit is further provided between each mixer and the control device.

[0010] According to the embodiment of the second aspect of the present invention, a flow velocity measuring method is applied to the flow velocity measuring device as described in the embodiment of the first aspect above. The method includes: Obtain all absolute frequency differences; Determine the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to all the absolute frequency differences; The frequency to be measured is calculated according to the size relationship, the target frequency difference absolute value, and the reference frequency corresponding to the target frequency difference absolute value, wherein the target frequency difference absolute value is one of all frequency difference absolute values ​​that is greater than the preset minimum frequency and less than the preset maximum frequency.

[0011] The flow velocity measurement method according to the embodiment of the present invention has at least the following beneficial effects: By mixing the echo signal with at least two mixers, the absolute value of the frequency difference between the measured frequency and the corresponding reference frequency of at least two echo signals can be obtained. However, since the mixer obtains an absolute value, the measured frequency cannot be directly calculated. The magnitude relationship between the measured frequency and all reference frequencies can be determined according to all the absolute values ​​of the frequency differences, so that the measured frequency can be calculated by the absolute value of the target frequency difference and the reference frequency corresponding to the absolute value of the target frequency difference. Since the output value of the mixer is less than the preset minimum frequency or greater than the preset maximum frequency, the reliability of the measured value will be discounted. Therefore, selecting one of all the absolute values ​​of the frequency difference that is greater than the preset minimum frequency and less than the preset maximum frequency for calculation can ensure the reliability of the calculation result. The frequency after mixing can be accurate to 1Hz, which improves the frequency measurement accuracy compared to the frequency measurement of the existing embedded chip, and does not require FFT analysis, saving time and calculation. The flow velocity measurement method of the embodiment of the present invention can improve the frequency measurement accuracy and reduce time consumption.

[0012] According to some embodiments of the present invention, the number of mixers is two, the two corresponding reference frequencies are respectively recorded as a first reference frequency and a second reference frequency, and the first reference frequency is less than the second reference frequency, and the two corresponding frequency difference absolute values ​​are respectively recorded as a first frequency difference absolute value and a second frequency difference absolute value; The step of determining the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to the absolute values ​​of all frequency differences includes: If the sum of the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, it is determined that the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency; If the difference between the first frequency difference absolute value and the second frequency difference absolute value is equal to the difference between the first reference frequency and the second reference frequency, and the first frequency difference absolute value is smaller than the second frequency difference absolute value, it is determined that the magnitude relationship is that the frequency to be measured is smaller than the first reference frequency; If the difference between the first frequency difference absolute value and the second frequency difference absolute value is equal to the difference between the first reference frequency and the second reference frequency, and the first frequency difference absolute value is greater than the second frequency difference absolute value, the magnitude relationship is determined to be that the measured frequency is greater than the second reference frequency.

[0013] According to some embodiments of the present invention, the step of calculating the frequency to be measured according to the magnitude relationship, the target frequency difference absolute value, and a reference frequency corresponding to the target frequency difference absolute value includes: If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the absolute value of the second frequency difference is subtracted from the second reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is added to the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is subtracted from the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the second reference frequency is subtracted from the absolute value of the second frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is added to the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the second reference frequency is added to the absolute value of the second frequency difference to obtain the frequency to be measured.

[0014] According to some embodiments of the present invention, the number of mixers is three, the three corresponding reference frequencies are respectively recorded as a first reference frequency, a second reference frequency, and a third reference frequency, and the first reference frequency is less than the second reference frequency, the second reference frequency is less than the third reference frequency, and the three corresponding frequency difference absolute values ​​are respectively recorded as a first frequency difference absolute value, a second frequency difference absolute value, and a third frequency difference absolute value, the echo signal is within a preset frequency range, the preset frequency range is equally divided into four frequency intervals, and the first reference frequency, the second reference frequency, and the third reference frequency are respectively the right boundary values ​​of the first three frequency intervals; The step of determining the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to the absolute values ​​of all frequency differences includes: Determine half of the difference between the first reference frequency and the second reference frequency, and record it as the set minimum frequency; Any two of the first frequency difference absolute value, the second frequency difference absolute value, and the third frequency difference absolute value that are both greater than the set minimum frequency are recorded as the first comparison frequency difference absolute value and the second comparison frequency difference absolute value, wherein the reference frequency corresponding to the first comparison frequency difference absolute value is recorded as the first comparison reference frequency, and the reference frequency corresponding to the second comparison frequency difference absolute value is recorded as the second comparison reference frequency; The magnitude relationship between the frequency to be measured and the first comparison reference frequency and the second comparison reference frequency is determined according to the first comparison frequency difference absolute value and the second comparison frequency difference absolute value.

[0015] The control device according to the third aspect of the present invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the flow velocity measurement method as described in the second aspect of the present invention when executing the computer program. Since the control device adopts all the technical solutions of the flow velocity measurement method of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0016] The computer-readable storage medium according to the fourth aspect of the present invention stores computer-executable instructions, and the computer-executable instructions are used to execute the flow velocity measurement method as described in the second aspect of the present invention. Since the computer-readable storage medium adopts all the technical solutions of the flow velocity measurement method of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0017] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic diagram of a flow velocity measuring device according to an embodiment of the present invention; Figure 2 is a schematic diagram of selecting three reference frequencies of three mixers according to an embodiment of the present invention; Figure 3 is a schematic diagram of the magnitude relationship between a frequency to be measured and three reference frequencies according to an embodiment of the present invention; Figure 4 is a schematic diagram of selecting two reference frequencies of two mixers according to an embodiment of the present invention; Figure 5is a flow chart of a flow velocity measurement method according to an embodiment of the present invention.

[0019] Reference numerals: Ultrasonic transmitting probe 100; Ultrasonic receiving probe 200; Mixer 300; Control device 400; Signal amplification and filtering circuit 500; Filter 600. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0022] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 understood as a limitation on the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0024] The following will be combined Figures 1 to 4 A clear and complete description is given of the flow rate measuring device according to the embodiment of the present invention. Obviously, the embodiment described below is only a part of the embodiments of the present invention, but not all of the embodiments.

[0025] refer to Figures 1 to 4 , Figure 1 is a schematic diagram of a flow velocity measuring device according to an embodiment of the present invention; Figure 2 is a schematic diagram of selecting three reference frequencies of three mixers 300 according to an embodiment of the present invention; Figure 3 is a schematic diagram of the magnitude relationship between a frequency to be measured and three reference frequencies according to an embodiment of the present invention; Figure 4FIG. 1 is a schematic diagram of selecting two reference frequencies of two mixers 300 according to an embodiment of the present invention.

[0026] According to the flow velocity measuring device of the first embodiment of the present invention, the device includes an ultrasonic transmitting probe 100 , an ultrasonic receiving probe 200 , a control device 400 and at least two mixers 300 .

[0027] An ultrasonic transmitting probe 100, used for transmitting ultrasonic signals; The ultrasonic receiving probe 200 is used to receive the echo signal generated by the ultrasonic signal after being reflected by the underwater obstacle; At least two mixers 300, each having an input end electrically connected to the ultrasonic receiving probe 200, different mixers 300 having different reference frequencies, each mixer 300 being used to output an absolute value of a frequency difference between an echo signal and a corresponding reference frequency, wherein the difference between any two reference frequencies is greater than twice a preset minimum frequency and less than a difference between a preset maximum frequency and a preset minimum frequency; The control device 400 is respectively connected to the output ends of all mixers 300, and is used to obtain all frequency difference absolute values, determine the size relationship between the measured frequency of the echo signal and all reference frequencies according to all frequency difference absolute values, and calculate the measured frequency according to the size relationship, the target frequency difference absolute value, and the reference frequency corresponding to the target frequency difference absolute value, wherein the target frequency difference absolute value is one of all frequency difference absolute values ​​that is greater than a preset minimum frequency and less than a preset maximum frequency.

[0028] In some embodiments, reference Figure 1 The ultrasonic transmitting probe 100 transmits a 1MHz ultrasonic signal (the reason for using 1MHz is that ultrasonic waves in this frequency band are more easily propagated in water). After encountering a substance in the water (Q point), the ultrasonic wave forms a reflected wave (i.e., an echo signal), which is received by the ultrasonic receiving probe 200. Water flow rate The constraint formula is: ; in, is the water flow rate, It is the frequency difference generated by the ultrasonic signal from sending to receiving. is the propagation speed of ultrasound in the fluid, is the frequency of the ultrasonic signal, It is the angle between the ultrasonic wave propagation direction and the fluid flow direction (approximately equal to 0).

[0029] It can be seen from the above formula that the physical quantity to be measured is actually changed from speed to frequency.

[0030] In the process of measuring frequency, the target measurement accuracy is 1Hz. However, considering the cost performance, the embedded chips we generally use are low-end embedded chips. The frequency measurement of existing low-end embedded chips can only be accurate to microseconds, and can only distinguish 1MHz and 1.000001MHz, but cannot distinguish 1.0000001MHz. At the same time, if you want to measure accurately, you need to measure for 1 second to measure accurately. If you only measure for 0.1 seconds, then the measured value should be 0.1MHz or 0.100001MHz (the last digit is determined by the microsecond level, which can be understood as a resolution problem). After multiplying by 10, the frequency obtained is 1MHz or 1.00001MHz, and the resolution becomes 10Hz instead of 1Hz. If the FFT method is used (which is also the method used by many devices now), the waveform needs to be sampled by the analog-to-digital conversion module, and then Fourier transform is performed to obtain a frequency value. It also requires a sampling time of 1 second to be accurate to 1Hz, and a complex calculation process is also required.

[0031] In addition, it should be noted that the flow rate measuring device of the present invention is battery-powered, and the sampling time of 0.1 second is set in consideration of energy consumption when powered by the battery. The advantage of the present invention is that the measurement task can be completed in a shorter time, energy consumption can be reduced, and measurement costs can be reduced.

[0032] It is understandable that the mixer 300 is used to output the absolute value of the frequency difference between the echo signal and the corresponding reference frequency, that is, it is impossible to determine the frequency to be measured of the echo signal with only one mixer 300. For a reference point of 1 MHz, the value obtained by mixing 0.99 MHz with it and the value obtained by mixing 1.01 MHz with it are the same. Therefore, at least two mixers 300 are required to determine the magnitude relationship between the frequency to be measured of the echo signal and the two reference frequencies through the corresponding two absolute values ​​of the frequency difference, and then the frequency to be measured can be calculated according to the magnitude relationship, the absolute value of the target frequency difference, and the reference frequency corresponding to the absolute value of the target frequency difference. And because the reliability of the measured value will be discounted when the output value of the mixer 300 is less than the preset minimum frequency or greater than the preset maximum frequency, the difference between any two reference frequencies must be greater than twice the preset minimum frequency and less than the difference between the preset maximum frequency and the preset minimum frequency, to ensure that the output result of at least one mixer 300 is valid, and then one of all the absolute values ​​of the frequency difference that is greater than the preset minimum frequency and less than the preset maximum frequency is selected for calculation, so as to ensure the reliability of the calculation result.

[0033] In some embodiments of the present invention, reference Figures 1 to 4, the number of mixers 300 is two, the two corresponding reference frequencies are respectively recorded as the first reference frequency and the second reference frequency, and the first reference frequency is less than the second reference frequency, and the two corresponding frequency difference absolute values ​​are respectively recorded as the first frequency difference absolute value and the second frequency difference absolute value; The magnitude relationship between the measured frequency of the echo signal and all reference frequencies is determined according to the absolute values ​​of all frequency differences, including: If the sum of the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, it is determined that the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency; If the difference between the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, and the absolute value of the first frequency difference is smaller than the absolute value of the second frequency difference, it is determined that the magnitude relationship is that the frequency to be measured is smaller than the first reference frequency; If the difference between the first frequency difference absolute value and the second frequency difference absolute value is equal to the difference between the first reference frequency and the second reference frequency, and the first frequency difference absolute value is greater than the second frequency difference absolute value, it is determined that the measured frequency is greater than the second reference frequency.

[0034] In some embodiments of the present invention, reference Figures 1 to 4 , the frequency to be measured is calculated according to the size relationship, the absolute value of the target frequency difference, and the reference frequency corresponding to the absolute value of the target frequency difference, including: If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the absolute value of the second frequency difference is subtracted from the second reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is added to the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the absolute value of the first frequency difference is subtracted from the first reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the absolute value of the second frequency difference is subtracted from the second reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is added to the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the second reference frequency is added to the absolute value of the second frequency difference to obtain the frequency to be measured.

[0035] Next, the calculation process is described with a specific example. In this example, the preset minimum frequency is 2KHz (i.e. 0.002MHz), the preset maximum frequency is 50KHz (i.e. 0.05MHz), and the reference frequency is 100kHz (i.e. 0.05MHz). Figure 3 , select the two reference frequencies: Reference 1 (0.9925MHz) and Reference 2 (1MHz).

[0036] The absolute value of the frequency difference between the measured frequency and reference 1 is 0.0025MHz, recorded as f1, and the absolute value of the frequency difference between the measured frequency and reference 2 is 0.01MHz, recorded as f2, f2-f1=0.0075MHz=1MHz-0.9925MHz, then the measured frequency is outside reference 1 (0.9925MHz) and reference 2 (1MHz), and the absolute value of the first frequency difference (0.0025MHz) is less than the absolute value of the second frequency difference (0.01MHz), then the measured frequency is 0.9925MHz away from reference 1 (0.9925MHz) and reference 2 (1MHz). 925MHz) is closer, so the frequency to be measured is on the left of reference 1 (0.9925MHz), and the absolute value of the first frequency difference (0.0025MHz) and the absolute value of the second frequency difference (0.01MHz) are both greater than 0.002MHz and less than 0.05MHz, so any one of them can be selected for calculation, that is, 0.9925MHz-0.0025MHz=0.99MHz, or, 1MHz-0.01MHz=0.99MHz, and the frequency to be measured is 0.99MHz.

[0037] In some embodiments, during the circuit design process, the problem of MCU processor and circuit coordination may occur. When two mixers 300 are used, it is possible that the reference frequency of one of them is exactly equal to the frequency to be measured. Then the output result of this mixer 300 has no calculation meaning, which is equivalent to the data here being fuzzy. The program needs to make many unexpected supplements. Since the flow rate of water is generally within plus or minus 10 meters per second, the received frequency range is generally: 0.985MHz to 1.015MHz. The two reference frequencies can be set outside this range, that is, Figure 4 Reference 4 (0.983 MHz) and reference 5 (1.017 MHz) in the mixer 300 can ensure that the frequency to be measured is generally not the same as the reference frequency of the mixer 300. There is also a frequency difference between the frequency to be measured and reference 4 (0.983 MHz) and reference 5 (1.017 MHz) greater than 2 kHz and less than 50 kHz. Relatively speaking, the data will be more accurate.

[0038] It should be noted that, since the frequency to be measured is not necessarily within the range of 0.985 MHz to 1.015 MHz in actual situations, two mixers 300 are still needed to determine the value of the frequency to be measured.

[0039] According to the flow velocity measuring device of the embodiment of the present invention, by mixing the echo signal with at least two mixers 300, the absolute value of the frequency difference between the measured frequency and the corresponding reference frequency of at least two echo signals can be obtained. However, since the mixer 300 obtains an absolute value, the measured frequency cannot be directly calculated. The magnitude relationship between the measured frequency and all reference frequencies can be determined according to all the absolute values ​​of the frequency differences, so that the measured frequency can be calculated by the target frequency difference absolute value and the reference frequency corresponding to the target frequency difference absolute value. Since the output value of the mixer 300 is less than the preset minimum frequency or greater than the preset maximum frequency, the reliability of the measured value will be discounted, so selecting one of all the frequency difference absolute values ​​that is greater than the preset minimum frequency and less than the preset maximum frequency for calculation can ensure the reliability of the calculation result. The frequency after mixing can be accurate to 1Hz, which improves the frequency measurement accuracy compared with the frequency measurement of the existing embedded chip, and does not need to perform FFT analysis, saving time and calculation. The flow velocity measuring device of the embodiment of the present invention can improve the frequency measurement accuracy and reduce time consumption.

[0040] In some embodiments of the present invention, reference Figures 1 to 3 , the number of mixers 300 is three. With two mixers 300, it can be determined that the measurement result of at least one mixer 300 is accurate, and the value of the frequency to be measured can be accurately calculated by determining the magnitude relationship between the frequency to be measured and the reference frequency of the mixer 300, as well as the output value of the mixer 300 and the corresponding reference frequency. With three mixers 300, there are more reference quantities, which can make the calculation result more accurate, and can avoid the situation where two mixers 300 are used, but the reference frequency of one of the mixers 300 is exactly equal to the frequency to be measured, and the calculation cannot be performed.

[0041] It should be noted that the number of mixers 300 may be greater, which should not be regarded as a limitation to the present invention.

[0042] In some embodiments of the present invention, reference Figures 1 to 3 The echo signal is within a preset frequency range, the preset frequency range is equally divided into four frequency intervals, and the three reference frequencies corresponding to the three mixers 300 are respectively the right boundary values ​​of the first three frequency intervals.

[0043] The three corresponding reference frequencies are respectively recorded as the first reference frequency, the second reference frequency and the third reference frequency, and the first reference frequency is less than the second reference frequency, the second reference frequency is less than the third reference frequency, the three corresponding frequency difference absolute values ​​are respectively recorded as the first frequency difference absolute value, the second frequency difference absolute value and the third frequency difference absolute value, the echo signal is within a preset frequency range, the preset frequency range is equally divided into four frequency intervals, the first reference frequency, the second reference frequency and the third reference frequency are respectively the right boundary values ​​of the first three frequency intervals; The magnitude relationship between the measured frequency of the echo signal and all reference frequencies is determined according to the absolute values ​​of all frequency differences, including: Determine half of the difference between the first reference frequency and the second reference frequency, and record it as the set minimum frequency; Any two of the first frequency difference absolute value, the second frequency difference absolute value, and the third frequency difference absolute value that are both greater than the set minimum frequency are recorded as the first comparison frequency difference absolute value and the second comparison frequency difference absolute value, wherein the reference frequency corresponding to the first comparison frequency difference absolute value is recorded as the first comparison reference frequency, and the reference frequency corresponding to the second comparison frequency difference absolute value is recorded as the second comparison reference frequency; The magnitude relationship between the frequency to be measured and the first comparison reference frequency and the second comparison reference frequency is determined according to the first comparison frequency difference absolute value and the second comparison frequency difference absolute value.

[0044] In some embodiments, since the flow rate of water is generally within plus or minus 10 meters per second, the received frequency range should be: 0.985MHz to 1.015MHz (i.e., the preset frequency range), and the three reference frequencies corresponding to the three mixers 300 are reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz).

[0045] Half of the difference between any two of reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz) is equal to 0.00375MHz, which is used to set the minimum frequency. The function of setting the minimum frequency is to filter out the one closest to the measured frequency from the three reference frequencies and calculate with the other two valid reference frequencies. Figure 2 The first frequency difference absolute value, the second frequency difference absolute value and the third frequency difference absolute value corresponding to the measured frequency and reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz) are recorded as f1, f2 and f3 respectively, and C, D, E and F are the midpoints of the four frequency intervals respectively.

[0046] For point B, f1>0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, and any two references, namely f1, f2, and f3, are acceptable.

[0047] For point C, f1=0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, and any two references, namely f1, f2, and f3, are acceptable.

[0048] For the point between C and D: f1<0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, take reference 2, reference 3, that is, f2, f3.

[0049] For point D, f1=0.00375MHz, f2= 0.00375MHz, f3>0.00375MHz, any two references, i.e. f1, f2, f3 are acceptable.

[0050] For the point between D and E, f1>0.00375MHz, f2<0.00375MHz, f3>0.00375MHz, take reference 1, reference 3, that is, f1, f3.

[0051] For point E, f1>0.00375MHz, f2= 0.00375MHz, f3=0.00375MHz, any two references, i.e. f1, f2, f3 are acceptable.

[0052] For the point between E and F, f1>0.00375MHz, f2>0.00375MHz, f3<0.00375MHz, take reference 1 and reference 2, that is, f1 and f2.

[0053] For point F and subsequent points, f1>0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, and any two references, i.e. f1, f2, and f3, are acceptable.

[0054] The minimum frequency that can be calculated is 3.75KHz, and the maximum frequency is the frequency from the left endpoint to reference 3 or the right endpoint to reference 1, which is 22.5KHz. For high frequencies around 1MHz, 1Hz is 1 microsecond, which is the limit of the chip. However, for the frequency after mixing, the highest frequency is 22.5KHz, and 1Hz is at least 44uS, so we can be accurate to 0.025Hz. Considering that we only use 0.1 seconds of measurement time, we need to multiply this accuracy by 10, so the accuracy is 0.25Hz, so it can be accurate to 1Hz.

[0055] The calculation process is described below with a specific embodiment. In this embodiment, the preset minimum frequency is 2 KHz (ie 0.002 MHz), and the preset maximum frequency is 50 KHz (ie 0.05 MHz).

[0056] refer to Figure 3, the first frequency difference absolute value, the second frequency difference absolute value and the third frequency difference absolute value corresponding to the measured frequency and reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz) are 0.0025MHz, 0.01MHz and 0.0175MHz respectively, recorded as f1, f2 and f3 respectively, 0.0025MHz<0.00375MHz, take 0.01MHz and 0.0175MHz for calculation, 0.01MHz-0.0175MHz=0.0075MHz=1MHz-1.0 0.075MHz, so the frequency to be measured is outside reference 2 (1MHz) and reference 3 (1.0075MHz). Because the frequency to be measured is closest to reference 1 (0.9925MHz), the frequency to be measured is on the left of reference 2 (1MHz). 0.01MHz and 0.0175MHz are both greater than 0.002MHz and less than 0.05MHz, so you can choose any one for calculation, that is, the frequency to be measured is 1MHz-0.01MHz=0.99MHz, or 1.0075MHz-0.0175MHz=0.99MHz.

[0057] It should be noted that it is simpler from a programming perspective to divide the preset frequency range equally among reference 1, reference 3 and reference 3. It is also possible that reference 1, reference 3 and reference 3 do not divide the preset frequency range equally, but the program will be more complicated and it cannot be regarded as a limitation of the present invention.

[0058] In some embodiments of the present invention, reference Figure 1 A signal amplification and filtering circuit 500 is further provided between the ultrasonic receiving probe 200 and each mixer 300, and a filtering circuit is further provided between each mixer 300 and the control device 400. In some embodiments, there are three mixers 300, and the filtering circuit includes three filters 600, which are connected to the output ends of the three mixers 300 in a one-to-one correspondence.

[0059] It should be noted that the functions and principles of the signal amplification and filtering circuit 500 and the filtering circuit are prior arts known to those skilled in the art and will not be elaborated herein.

[0060] The following will be combined Figures 1 to 5 A flow rate measurement method according to an embodiment of the present invention is described clearly and completely. Obviously, the embodiment described below is only a part of the embodiments of the present invention, but not all of the embodiments.

[0061] refer to Figures 1 to 5 , Figure 1 is a schematic diagram of a flow velocity measuring device according to an embodiment of the present invention; Figure 2 is a schematic diagram of selecting three reference frequencies of three mixers 300 according to an embodiment of the present invention; Figure 3is a schematic diagram of the magnitude relationship between a frequency to be measured and three reference frequencies according to an embodiment of the present invention; Figure 4 is a schematic diagram of selecting two reference frequencies of two mixers 300 according to an embodiment of the present invention; Figure 5 is a flow chart of a flow velocity measurement method according to an embodiment of the present invention.

[0062] The flow velocity measurement method according to the second aspect of the present invention is applied to the flow velocity measurement device according to the first aspect of the present invention, and the method includes: Get the absolute values ​​of all frequency differences; Determine the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to the absolute values ​​of all frequency differences; The frequency to be measured is calculated according to the size relationship, the target frequency difference absolute value, and the reference frequency corresponding to the target frequency difference absolute value, wherein the target frequency difference absolute value is one of all frequency difference absolute values ​​that is greater than a preset minimum frequency and less than a preset maximum frequency.

[0063] It is understandable that the mixer 300 is used to output the absolute value of the frequency difference between the echo signal and the corresponding reference frequency, that is, it is impossible to determine the frequency to be measured of the echo signal with only one mixer 300. For a reference point of 1 MHz, the value obtained by mixing 0.99 MHz with it and the value obtained by mixing 1.01 MHz with it are the same. Therefore, at least two mixers 300 are required to determine the magnitude relationship between the frequency to be measured of the echo signal and the two reference frequencies through the corresponding two absolute values ​​of the frequency difference, and then the frequency to be measured can be calculated according to the magnitude relationship, the absolute value of the target frequency difference, and the reference frequency corresponding to the absolute value of the target frequency difference. And because the reliability of the measured value will be discounted when the output value of the mixer 300 is less than the preset minimum frequency or greater than the preset maximum frequency, the difference between any two reference frequencies must be greater than twice the preset minimum frequency and less than the difference between the preset maximum frequency and the preset minimum frequency, to ensure that the output result of at least one mixer 300 is valid, and then one of all the absolute values ​​of the frequency difference that is greater than the preset minimum frequency and less than the preset maximum frequency is selected for calculation, so as to ensure the reliability of the calculation result.

[0064] According to the flow velocity measurement method of the embodiment of the present invention, by mixing the echo signal with at least two mixers 300, the absolute value of the frequency difference between the measured frequency and the corresponding reference frequency of at least two echo signals can be obtained. However, since the mixer 300 obtains an absolute value, the measured frequency cannot be directly calculated. The magnitude relationship between the measured frequency and all reference frequencies can be determined according to all the absolute values ​​of the frequency differences, so that the measured frequency can be calculated by the target frequency difference absolute value and the reference frequency corresponding to the target frequency difference absolute value. Since the output value of the mixer 300 is less than the preset minimum frequency or greater than the preset maximum frequency, the reliability of the measured value will be discounted, so selecting one of all the frequency difference absolute values ​​that is greater than the preset minimum frequency and less than the preset maximum frequency for calculation can ensure the reliability of the calculation result. The frequency after mixing can be accurate to 1Hz, which improves the frequency measurement accuracy compared with the frequency measurement of the existing embedded chip, and does not require FFT analysis, saving time and calculation. The flow velocity measurement method of the embodiment of the present invention can improve the frequency measurement accuracy and reduce time consumption.

[0065] In some embodiments of the present invention, reference Figures 1 to 4 , the number of mixers 300 is two, the two corresponding reference frequencies are respectively recorded as the first reference frequency and the second reference frequency, and the first reference frequency is less than the second reference frequency, and the two corresponding frequency difference absolute values ​​are respectively recorded as the first frequency difference absolute value and the second frequency difference absolute value; The magnitude relationship between the measured frequency of the echo signal and all reference frequencies is determined according to the absolute values ​​of all frequency differences, including: If the sum of the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, it is determined that the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency; If the difference between the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, and the absolute value of the first frequency difference is smaller than the absolute value of the second frequency difference, it is determined that the magnitude relationship is that the frequency to be measured is smaller than the first reference frequency; If the difference between the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, and the absolute value of the first frequency difference is greater than the absolute value of the second frequency difference, it is determined that the magnitude relationship is that the measured frequency is greater than the second reference frequency.

[0066] In some embodiments of the present invention, reference Figures 1 to 4 , the frequency to be measured is calculated according to the size relationship, the absolute value of the target frequency difference, and the reference frequency corresponding to the absolute value of the target frequency difference, including: If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the absolute value of the second frequency difference is subtracted from the second reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency, less than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, add the absolute value of the first frequency difference to the first reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, subtract the absolute value of the first frequency difference from the first reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, subtract the absolute value of the second frequency difference from the second reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, add the absolute value of the first frequency difference to the first reference frequency to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, add the absolute value of the second frequency difference to the second reference frequency to obtain the frequency to be measured.

[0067] Next, a specific embodiment is used to illustrate the calculation process. In this embodiment, the preset minimum frequency is 2KHz (i.e., 0.002MHz), and the preset maximum frequency is 50KHz (i.e., 0.05MHz). Refer to Figure 3 and select two reference frequencies, reference 1 (0.9925MHz) and reference 2 (1MHz).

[0068] The absolute value of the frequency difference between the frequency to be measured and reference 1 is 0.0025MHz, denoted as f1, and the absolute value of the frequency difference between the frequency to be measured and reference 2 is 0.01MHz, denoted as f2. f2 - f1 = 0.0075MHz = 1MHz - 0.9925MHz. Then the frequency to be measured is outside of reference 1 (0.9925MHz) and reference 2 (1MHz), and the absolute value of the first frequency difference (0.0025MHz) is less than the absolute value of the second frequency difference (0.01MHz). So the frequency to be measured is closer to reference 1 (0.9925MHz). Therefore, the frequency to be measured is on the left side of reference 1 (0.9925MHz), and both the absolute value of the first frequency difference (0.0025MHz) and the absolute value of the second frequency difference (0.01MHz) are greater than 0.002MHz and less than 0.05MHz. Thus, either one can be selected for calculation, that is, 0.9925MHz - 0.0025MHz = 0.99MHz, or 1MHz - 0.01MHz = 0.99MHz. The frequency to be measured is 0.99MHz.

[0069] In some embodiments, during the circuit design process, the problem of MCU processor and circuit coordination may occur. When two mixers 300 are used, it is possible that the reference frequency of one of them is exactly equal to the frequency to be measured. Then the output result of this mixer 300 has no calculation meaning, which is equivalent to the data here being fuzzy. The program needs to make many unexpected supplements. Since the flow rate of water is generally within plus or minus 10 meters per second, the received frequency range is generally: 0.985MHz to 1.015MHz. The two reference frequencies can be set outside this range, that is, Figure 4 Reference 4 (0.983 MHz) and reference 5 (1.017 MHz) in the mixer 300 can ensure that the frequency to be measured is generally not the same as the reference frequency of the mixer 300. There is also a frequency difference between the frequency to be measured and reference 4 (0.983 MHz) and reference 5 (1.017 MHz) greater than 2 kHz and less than 50 kHz. Relatively speaking, the data will be more accurate.

[0070] It should be noted that, since the frequency to be measured is not necessarily within the range of 0.985 MHz to 1.015 MHz in actual situations, two mixers 300 are still needed to determine the value of the frequency to be measured.

[0071] In some embodiments of the present invention, reference Figures 1 to 3 , the number of mixers 300 is three, the three corresponding reference frequencies are respectively recorded as the first reference frequency, the second reference frequency and the third reference frequency, and the first reference frequency is less than the second reference frequency, the second reference frequency is less than the third reference frequency, the three corresponding frequency difference absolute values ​​are respectively recorded as the first frequency difference absolute value, the second frequency difference absolute value and the third frequency difference absolute value, the echo signal is within the preset frequency range, the preset frequency range is equally divided into four frequency intervals, the first reference frequency, the second reference frequency and the third reference frequency are respectively the right boundary values ​​of the first three frequency intervals; The magnitude relationship between the measured frequency of the echo signal and all reference frequencies is determined according to the absolute values ​​of all frequency differences, including: Determine half of the difference between the first reference frequency and the second reference frequency, and record it as the set minimum frequency; Any two of the first frequency difference absolute value, the second frequency difference absolute value, and the third frequency difference absolute value that are both greater than the set minimum frequency are recorded as the first comparison frequency difference absolute value and the second comparison frequency difference absolute value, wherein the reference frequency corresponding to the first comparison frequency difference absolute value is recorded as the first comparison reference frequency, and the reference frequency corresponding to the second comparison frequency difference absolute value is recorded as the second comparison reference frequency; The magnitude relationship between the frequency to be measured and the first comparison reference frequency and the second comparison reference frequency is determined according to the first comparison frequency difference absolute value and the second comparison frequency difference absolute value.

[0072] By using two mixers 300, it can be determined that the measurement result of at least one mixer 300 is accurate, and the value of the frequency to be measured can be accurately calculated by determining the magnitude relationship between the frequency to be measured and the reference frequency of the mixer 300, as well as the output value of the mixer 300 and the corresponding reference frequency. By using three mixers 300, there are more reference quantities, which can make the calculation result more accurate, and it can avoid the situation where two mixers 300 are used, but the reference frequency of one of the mixers 300 is exactly equal to the frequency to be measured, and the calculation cannot be performed.

[0073] It should be noted that the number of mixers 300 may be greater, which should not be regarded as a limitation to the present invention.

[0074] In some embodiments, since the flow rate of water is generally within plus or minus 10 meters per second, the received frequency range should be: 0.985MHz to 1.015MHz (i.e., the preset frequency range), and the three reference frequencies corresponding to the three mixers 300 are reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz).

[0075] Half of the difference between any two of reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz) is equal to 0.00375MHz, which is used to set the minimum frequency. The function of setting the minimum frequency is to filter out the one closest to the measured frequency from the three reference frequencies and calculate with the other two valid reference frequencies. Figure 2 The first frequency difference absolute value, the second frequency difference absolute value and the third frequency difference absolute value corresponding to the measured frequency and reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz) are recorded as f1, f2 and f3 respectively, and C, D, E and F are the midpoints of the four frequency intervals respectively.

[0076] For point B, f1>0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, and any two references, namely f1, f2, and f3, are acceptable.

[0077] For point C, f1=0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, and any two references, namely f1, f2, and f3, are acceptable.

[0078] For the point between C and D: f1<0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, take reference 2, reference 3, that is, f2, f3.

[0079] For point D, f1=0.00375MHz, f2= 0.00375MHz, f3>0.00375MHz, any two references, i.e. f1, f2, f3 are acceptable.

[0080] For the point between D and E, f1>0.00375MHz, f2<0.00375MHz, f3>0.00375MHz, take reference 1, reference 3, that is, f1, f3.

[0081] For point E, f1>0.00375MHz, f2= 0.00375MHz, f3=0.00375MHz, any two references, i.e. f1, f2, f3 are acceptable.

[0082] For the point between E and F, f1>0.00375MHz, f2>0.00375MHz, f3<0.00375MHz, take reference 1 and reference 2, that is, f1 and f2.

[0083] For point F and subsequent points, f1>0.00375MHz, f2>0.00375MHz, f3>0.00375MHz, and any two references, i.e. f1, f2, and f3, are acceptable.

[0084] The minimum frequency that can be calculated is 3.75KHz, and the maximum frequency is the frequency from the left endpoint to reference 3 or the right endpoint to reference 1, which is 22.5KHz. For high frequencies around 1MHz, 1Hz is 1 microsecond, which is the limit of the chip. However, for the frequency after mixing, the highest frequency is 22.5KHz, and 1Hz is at least 44uS, so we can be accurate to 0.025Hz. Considering that we only use 0.1 seconds of measurement time, we need to multiply this accuracy by 10, so the accuracy is 0.25Hz, so it can be accurate to 1Hz.

[0085] The calculation process is described below with a specific embodiment. In this embodiment, the preset minimum frequency is 2 KHz (ie 0.002 MHz), and the preset maximum frequency is 50 KHz (ie 0.05 MHz).

[0086] refer to Figure 3, the first frequency difference absolute value, the second frequency difference absolute value and the third frequency difference absolute value corresponding to the measured frequency and reference 1 (0.9925MHz), reference 2 (1MHz) and reference 3 (1.0075MHz) are 0.0025MHz, 0.01MHz and 0.0175MHz respectively, recorded as f1, f2 and f3 respectively, 0.0025MHz<0.00375MHz, take 0.01MHz and 0.0175MHz for calculation, 0.01MHz-0.0175MHz=0.0075MHz=1MHz-1.0 0.075MHz, so the frequency to be measured is outside reference 2 (1MHz) and reference 3 (1.0075MHz). Because the frequency to be measured is closest to reference 1 (0.9925MHz), the frequency to be measured is on the left of reference 2 (1MHz). 0.01MHz and 0.0175MHz are both greater than 0.002MHz and less than 0.05MHz, so you can choose any one for calculation, that is, the frequency to be measured is 1MHz-0.01MHz=0.99MHz, or 1.0075MHz-0.0175MHz=0.99MHz.

[0087] It should be noted that it is simpler from a programming perspective to divide the preset frequency range equally among reference 1, reference 3 and reference 3. It is also possible that reference 1, reference 3 and reference 3 do not divide the preset frequency range equally, but the program will be more complicated and it cannot be regarded as a limitation of the present invention.

[0088] In addition, an embodiment of the present invention further provides a control device 400, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor and the memory may be connected via a bus or other means.

[0089] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0090] The non-transient software program and instructions required to implement the flow velocity measurement method of the above embodiment are stored in the memory, and when executed by the processor, the flow velocity measurement method of the above embodiment is executed.

[0091] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0092] In addition, an embodiment of the present invention also provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are executed by a processor or controller, for example, by the processor of the above embodiment, so that the above processor can execute the flow rate measurement method in the above embodiment.

[0093] It will be appreciated by those skilled in the art that all or some of the steps and systems in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transient medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0094] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A flow velocity measuring device, characterized in that: The device comprises: An ultrasonic transmitting probe, used for transmitting ultrasonic signals; An ultrasonic receiving probe, used to receive an echo signal generated by the ultrasonic signal reflected by an underwater obstacle; At least two mixers, each having an input end electrically connected to the ultrasonic receiving probe, different mixers having different reference frequencies, each mixer being used to output an absolute value of a frequency difference between the echo signal and a corresponding reference frequency, wherein the difference between any two reference frequencies is greater than twice a preset minimum frequency and less than a difference between a preset maximum frequency and the preset minimum frequency; A control device is connected to the output ends of all mixers respectively, and is used to obtain all frequency difference absolute values, determine the size relationship between the measured frequency of the echo signal and all reference frequencies according to all frequency difference absolute values, and calculate the measured frequency according to the size relationship, the target frequency difference absolute value, and the reference frequency corresponding to the target frequency difference absolute value, wherein the target frequency difference absolute value is one of all frequency difference absolute values ​​that is greater than the preset minimum frequency and less than the preset maximum frequency.

2. The flow velocity measuring device according to claim 1, characterized in that: The number of mixers is three.

3. The flow velocity measuring device according to claim 2, characterized in that: The echo signal is within a preset frequency range, the preset frequency range is equally divided into four frequency intervals, and the three reference frequencies corresponding to the three mixers are respectively the right boundary values ​​of the first three frequency intervals.

4. The flow velocity measuring device according to claim 1, characterized in that: A signal amplification and filtering circuit is also provided between the ultrasonic receiving probe and each mixer, and a filtering circuit is also provided between each mixer and the control device.

5. A flow velocity measurement method, characterized in that: Applied to the flow velocity measuring device according to any one of claims 1 to 4, the method comprises: Get the absolute values ​​of all frequency differences; Determine the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to the absolute values ​​of all frequency differences; The frequency to be measured is calculated according to the size relationship, the target frequency difference absolute value, and the reference frequency corresponding to the target frequency difference absolute value, wherein the target frequency difference absolute value is one of all frequency difference absolute values ​​that is greater than the preset minimum frequency and less than the preset maximum frequency.

6. The flow velocity measurement method according to claim 5, characterized in that: The number of the mixers is two, the two corresponding reference frequencies are respectively recorded as a first reference frequency and a second reference frequency, the first reference frequency is less than the second reference frequency, and the two corresponding frequency difference absolute values ​​are respectively recorded as a first frequency difference absolute value and a second frequency difference absolute value; The step of determining the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to the absolute values ​​of all frequency differences includes: If the sum of the absolute value of the first frequency difference and the absolute value of the second frequency difference is equal to the difference between the first reference frequency and the second reference frequency, it is determined that the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency; If the difference between the first frequency difference absolute value and the second frequency difference absolute value is equal to the difference between the first reference frequency and the second reference frequency, and the first frequency difference absolute value is smaller than the second frequency difference absolute value, it is determined that the magnitude relationship is that the frequency to be measured is smaller than the first reference frequency; If the difference between the first frequency difference absolute value and the second frequency difference absolute value is equal to the difference between the first reference frequency and the second reference frequency, and the first frequency difference absolute value is greater than the second frequency difference absolute value, the magnitude relationship is determined to be that the measured frequency is greater than the second reference frequency.

7. The flow velocity measurement method according to claim 6, characterized in that: The step of calculating the frequency to be measured according to the magnitude relationship, the target frequency difference absolute value, and a reference frequency corresponding to the target frequency difference absolute value includes: If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the second reference frequency is subtracted from the absolute value of the second frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the first reference frequency and less than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is added to the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is subtracted from the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is less than the first reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the second reference frequency is subtracted from the absolute value of the second frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency, and the absolute value of the first frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the first reference frequency is added to the absolute value of the first frequency difference to obtain the frequency to be measured; If the magnitude relationship is that the frequency to be measured is greater than the second reference frequency, and the absolute value of the second frequency difference is greater than the preset minimum frequency and less than the preset maximum frequency, the second reference frequency is added to the absolute value of the second frequency difference to obtain the frequency to be measured.

8. The flow velocity measurement method according to claim 5, characterized in that: The number of mixers is three, and the three corresponding reference frequencies are respectively recorded as a first reference frequency, a second reference frequency, and a third reference frequency, and the first reference frequency is less than the second reference frequency, and the second reference frequency is less than the third reference frequency, and the three corresponding frequency difference absolute values ​​are respectively recorded as a first frequency difference absolute value, a second frequency difference absolute value, and a third frequency difference absolute value, and the echo signal is within a preset frequency range, and the preset frequency range is equally divided into four frequency intervals, and the first reference frequency, the second reference frequency, and the third reference frequency are respectively the right boundary values ​​of the first three frequency intervals; The step of determining the magnitude relationship between the frequency to be measured of the echo signal and all reference frequencies according to the absolute values ​​of all frequency differences includes: Determine half of the difference between the first reference frequency and the second reference frequency, and record it as the set minimum frequency; Any two of the first frequency difference absolute value, the second frequency difference absolute value, and the third frequency difference absolute value that are both greater than the set minimum frequency are recorded as the first comparison frequency difference absolute value and the second comparison frequency difference absolute value, wherein the reference frequency corresponding to the first comparison frequency difference absolute value is recorded as the first comparison reference frequency, and the reference frequency corresponding to the second comparison frequency difference absolute value is recorded as the second comparison reference frequency; The magnitude relationship between the frequency to be measured and the first comparison reference frequency and the second comparison reference frequency is determined according to the first comparison frequency difference absolute value and the second comparison frequency difference absolute value.

9. A control device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the flow velocity measurement method according to any one of claims 5 to 8 is implemented.

10. A computer-readable storage medium storing computer-executable instructions, characterized in that: The computer executable instructions are used to execute the flow velocity measurement method according to any one of claims 5 to 8.

Images