Interference suppression method for ultrasonic flow measurement, medium and ultrasonic water meter

Abstract

The present invention discloses an interference suppression method for ultrasonic flow measurement, a medium, and an ultrasonic water meter, and relates to the technical field of smart water meters. Most existing smart ultrasonic water meters use the time difference method to calculate information such as flow velocity and flow, which is usually subject to various interferences during calculation, affecting the accuracy and stability of measurement. The present invention discloses an interference suppression method for ultrasonic flow measurement to solve the above problems. The method includes: automatically selecting the optimal interference suppression configuration according to the hardware to eliminate the interference of the hardware itself; based on the optimal interference suppression configuration, performing a multi-stage filtering of filtering-calculation-filtering-calculation-filtering on the collected information. The second aspect of the present invention discloses an ultrasonic water meter. The third aspect of the present invention discloses a computer-readable storage medium. The interference suppression method disclosed by the present invention can filter out interference such as bubble interference and electromagnetic interference of different degrees of severity, thereby ensuring the accuracy of the data and the stability of measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent water meters, and in particular to an interference suppression method for ultrasonic flow measurement, a medium and an ultrasonic water meter. Background Art

[0002] Smart ultrasonic water meters are modern metering devices that use ultrasonic flow measurement technology to accurately measure water flow velocity and subsequently calculate water volume flow. These meters use a built-in ultrasonic sensor to transmit and receive ultrasonic pulses. The meter measures water flow velocity based on the time or phase difference between the ultrasonic waves traveling through water. The meter then calculates instantaneous and cumulative flow rates based on the cross-sectional area of ​​the pipe.

[0003] Most existing smart ultrasonic water meters use the time-of-day method to calculate flow rate. The ultrasonic sensor of a smart ultrasonic water meter is equipped with a transducer. However, the performance of transducers of different models and manufacturers varies. Individual transducers of the same model also differ, meaning that the stability intervals of the echoes received by different transducers vary. Therefore, the same software configuration for the TDC metering chip cannot simultaneously adapt to these differences. Using the same configuration may introduce hardware interference from the transducer itself.

[0004] During the data collection process, smart ultrasonic water meters are often affected by electromagnetic interference in space, interference from the transducer's own accuracy, energy reflection interference caused by the pipe structure, flow field disturbance interference, etc., resulting in poor accuracy and stability of the ultrasonic water meter. When smart ultrasonic water meters are interfered with by the external environment, the traditional primary filtering algorithm has limited filtering capabilities and can only reduce the time difference fluctuations caused by the interference, but cannot eliminate this interference, which is not conducive to the precise measurement of energy and affects the accuracy and stability of the measurement. Summary of the Invention

[0005] To solve the above problems, the present invention provides an interference suppression method for ultrasonic flow measurement, comprising the following steps:

[0006] S1, selects the optimal interference suppression configuration based on the echo information of the upstream and downstream transducers at the same time;

[0007] S2, calculating the flight time difference of the echo based on the optimal interference suppression configuration, filtering the flight time difference to obtain the filtered flight time difference, and calculating the instantaneous flow velocity at the current moment based on the filtered flight time difference;

[0008] S3, calculating the filtered instantaneous flow velocity at the current moment by using the instantaneous flow velocities at multiple moments including the current moment.

[0009] Based on the above solution, the process of selecting the optimal interference suppression configuration in step S1 includes:

[0010] S11, the ultrasonic water meter collects and obtains the echoes of the upstream and downstream transducers at the same time, and selects the default n continuous waves from the echoes according to the initial configuration;

[0011] S12, calculating the flight time difference variance of n consecutive waves, and if the flight time difference variance is less than a first preset threshold, using the initial configuration as the optimal interference suppression configuration;

[0012] S13: If the flight time difference variance is greater than or equal to a first preset threshold, adjust the initial configuration to obtain an adjusted initial configuration, and use the adjusted initial configuration as the optimal interference suppression configuration.

[0013] Based on the above solution, the process of adjusting the initial configuration in step S13 includes:

[0014] S131, the ultrasonic water meter collects and obtains echoes from the upstream and downstream transducers at the same time, selects n' waves from the echoes, where n'>n, and sequentially selects n waves from the n' waves as a group of echoes to obtain multiple groups of echoes;

[0015] S132 , calculating the flight time variance of each group of echoes, and selecting the group of echoes with the smallest variance as the adjusted initial configuration.

[0016] Based on the above solution, the filtering of the flight time difference in step S2 is a multi-stage filtering.

[0017] Based on the above scheme, the first stage of filtering in the multi-stage filtering includes:

[0018] S21, filtering the flight time difference of the echo at the current time m, and calculating the variance of the filtered flight time difference;

[0019] S22: If the variance of the flight time difference is greater than or equal to the second preset threshold, the flight time difference at time m is discarded, and the flight time difference at time m-1 is used as the first-stage filtered flight time difference diff_ToF m ;

[0020] S23, if the flight time difference variance is less than the second preset threshold, the flight time difference at time m is used as the first-stage filtered flight time difference diff_ToF m .

[0021] Based on the above scheme, the second stage filtering in the multi-stage filtering includes:

[0022] S24, starting from time m, collects the first-stage filtered flight time difference {diff_ToF m-X+1 , diff_ToF m-X+2 , ... , diff_ToF m}, remove the a maximum value and a minimum value and calculate the average value to get the second-stage filtered flight time difference and get the second-stage filtered flight time difference diff_ToF m ';

[0023] S25, based on the second-stage filtering flight time difference diff_ToF m 'Calculate the instantaneous flow velocity dV at time m m .

[0024] Based on the above solution, the filtered instantaneous flow velocity at the current moment calculated in step S3 includes:

[0025] S26, starting from time m, collect the instantaneous flow velocity {dV m-Y+1 , dV m-Y+2 , ... ,dV m}, remove the b maximum values ​​and b minimum values ​​and calculate the average to obtain the filtered instantaneous flow velocity dV at time m (i.e., the current time).

[0026] A second aspect of the present invention provides an ultrasonic water meter, comprising:

[0027] means for selecting an optimal interference suppression configuration based on echo information of upstream and downstream transducers at the same moment;

[0028] means for calculating a time difference of flight of an echo based on an optimal interference suppression configuration, filtering the time difference of flight, and obtaining a filtered time difference of flight;

[0029] Device for calculating instantaneous flow velocity by filtering time-of-flight differences.

[0030] A third aspect of the present invention provides a computer-readable storage medium storing an executable computer program. When the computer program is executed, the above-mentioned interference suppression method for ultrasonic flow measurement is performed.

[0031] The advantages of the present invention are:

[0032] 1. During the initialization phase, the optimal interference suppression configuration is selected based on different transducers and the actual pipe structure in use, and is compatible with most standard meters and a few problem meters. For most standard meters, by selecting the default continuous n waves in the initial configuration, a stable echo area can be quickly obtained without affecting normal use. For a few problem meters, the software algorithm automatically selects a stable waveform from the echo for calculation, eliminating the need for separate debugging of the problem meter, improving the first-time production compliance rate and reducing the investment in manpower and material resources.

[0033] 2. In the calculation stage, a multi-stage filtering method is used to filter the obtained flight time difference. The filtering processing method of each stage is different to cope with the flight time difference data obtained under different interference severity. The single or several flight time difference data with a small proportion of abnormal values ​​are filtered through the first-stage filtering. If the proportion of abnormal values ​​is too large, the entire set of flight time difference data can be further filtered through the second-stage filtering, and the instantaneous flow velocity at the current moment can be calculated. If the instantaneous flow velocity at a certain moment is abnormal, it can be further filtered through the third-stage filtering. The multi-stage filtering of the present invention can have a better suppression effect on the bubble interference and electromagnetic interference of the meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 FIG. 1 is a schematic diagram of the structure of a user terminal according to an embodiment of the present invention.

[0035] Figure 2 FIG. 4 is a flow chart of an interference suppression method according to an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of a flow chart for selecting an optimal interference suppression configuration according to this embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the process of adjusting the initial configuration according to this embodiment of the present invention.

[0038] Figure 5 Schematic diagram of selecting data segments for this embodiment of the present invention.

[0039] Figure 6 2 is a flow chart of the first stage of filtering in the multi-stage filtering of the embodiment of the present invention.

[0040] Figure 7 2 is a flow chart of the second stage filtering in the multi-stage filtering of the embodiment of the present invention.

[0041] Figure 8 Schematic diagram of the overall process of multi-stage filtering of this embodiment of the present invention.

[0042] Figure 9 FIG. 1 is a schematic diagram of an ultrasonic water meter according to an embodiment of the present invention.

[0043] Reference numerals: measuring tube section 1 , ultrasonic transducer 2 . DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to specific embodiments.

[0045] The present invention provides a method for suppressing interference in ultrasonic flow measurement. Figure 1, is a schematic diagram of the terminal structure of an embodiment of the present invention. When in use, ultrasonic transducers 2 are respectively installed upstream and downstream of the measuring pipe section 1, wherein the ultrasonic transducers 2 are used to transmit and receive ultrasonic signals to each other. Due to the superposition of the ultrasonic signal and the water flow direction v, the propagation speed of the ultrasonic wave is different when it is downstream and upstream. The propagation speed increases when it is downstream and decreases when it is upstream. Different propagation times are taken for the same propagation distance. The flow velocity of the water flow can be calculated based on the different propagation times.

[0046] The measuring pipe segment 1 in this embodiment is straight. In other embodiments, the measuring pipe segment 1 is of other types, such as Z-shaped. Those skilled in the art will understand that the measuring pipe segment 1 in the figure is only used to explain the relevant hardware structure of the present application scheme, and does not constitute a limitation of the present application scheme on its structure or shape.

[0047] The ultrasonic transducer 2 in this embodiment is usually installed in an ultrasonic water meter and is used to receive and transmit ultrasonic waves through a piezoelectric circuit. In other embodiments, the ultrasonic transducer 2 can be in other forms, such as an ultrasonic probe or an ultrasonic sensor.

[0048] In this embodiment, a pair of ultrasonic transducers 2 is installed. It is easy to imagine that multiple pairs of ultrasonic transducers 2 are set in the measuring pipe section 1, and more accurate measurement data can be obtained by filtering the measurement data of the multiple pairs of ultrasonic transducers 2.

[0049] The ultrasonic water meter described above is mostly used to measure the flow velocity of the fluid in the measuring pipe section 1, and the flow rate of the fluid flowing through the ultrasonic water meter is further calculated based on the flow velocity. Most existing ultrasonic water meters use the time difference method to calculate the flow velocity. Specifically, the flow velocity is calculated based on the time difference between the upstream and downstream ultrasonic transducers receiving the ultrasonic wave. However, there are differences between ultrasonic transducers of different manufacturers, different models of ultrasonic transducers of the same manufacturer, and different individuals of the same model of ultrasonic transducers of the same manufacturer. Using the same filtering configuration in the ultrasonic water meter cannot simultaneously cope with these differences. Therefore, the present application provides an interference suppression method that selects the optimal interference suppression configuration according to different devices, which can automatically adapt to these differences and eliminates the need for manual debugging of problematic ultrasonic water meters, saving time and manpower.

[0050] See Figure 2 , is a flow chart of an interference suppression method according to an embodiment of the present invention, the interference suppression method comprising the following steps:

[0051] S1, select the optimal interference suppression configuration based on the echo information of the upstream and downstream transducers at the same time.

[0052] S2: Calculate the time difference of the echo based on the optimal interference suppression configuration, filter the time difference of the echo to obtain the filtered time difference of the echo, and calculate the instantaneous flow velocity at the current moment based on the filtered time difference of the echo.

[0053] S3, calculating the filtered instantaneous flow velocity at the current moment by using the instantaneous flow velocities at multiple moments including the current moment.

[0054] Among them, step S1 is the initialization stage of the ultrasonic water meter, and steps S2 and S3 are the metering stages of the ultrasonic water meter. In the initialization stage, the present application solution can fundamentally eliminate the interference of the hardware itself by selecting appropriate interference suppression configurations for different transducers and pipe section structures to improve measurement accuracy.

[0055] See Figure 3 , which is a flow chart of selecting the optimal interference suppression configuration according to this embodiment of the present invention. The process of selecting the optimal interference suppression configuration is as follows:

[0056] S11, the ultrasonic water meter collects and obtains echoes of the upstream and downstream transducers at the same time, and selects default n continuous waves from the echoes according to the initial configuration.

[0057] S12: Calculate the upstream and downstream flight time differences of n consecutive waves, calculate the flight time difference variance of n consecutive waves based on the upstream and downstream flight time differences, and if the flight time difference variance is less than a first preset threshold, use the initial configuration as the optimal interference suppression configuration. The formula is:

[0058]

[0059]

[0060] in, is the upstream flight time, is the downstream flight time, is the flight time difference, To calculate the variance function, is the flight time difference variance, and n represents the nth wave in the continuous waves.

[0061] The smaller the calculated variance is, the closer the time when the n consecutive waves pass through zero is, the more stable the working state of the transducer is, and the smaller the interference caused by the hardware itself such as the transducer or pipe structure is.

[0062] The first preset threshold can be different values ​​depending on the transducer or pipe segment structure. In this embodiment, the first preset threshold is 0.16ns. Technicians can set the specific value or type of the first preset threshold according to specific needs, such as percentage, etc., and this application does not limit this.

[0063] S13: If the flight time difference variance is greater than or equal to a first preset threshold, adjust the initial configuration to obtain an adjusted initial configuration, and use the adjusted initial configuration as the optimal interference suppression configuration.

[0064] During the initialization phase, the degree of compatibility between the current ultrasonic water meter hardware and software is determined by the flight time difference variance and the first preset threshold. When the flight time difference variance is less than the first preset threshold, it is considered that the current ultrasonic water meter hardware and software are highly compatible, and the interference caused by the hardware is negligible, and there is no need to replace the initial configuration. If the flight time difference variance is greater than or equal to the first preset threshold, it is considered that the current ultrasonic water meter hardware may cause greater interference, and the initial configuration needs to be adjusted separately to adapt to the current hardware.

[0065] See Figure 4 , which is a schematic diagram of the process of adjusting the initial configuration of this embodiment of the present invention. The process of adjusting the initial configuration includes:

[0066] S110, selecting n' waves from the echoes, where n'>n, and sequentially selecting n waves from the n' waves as a group of echoes, thereby obtaining multiple groups of echoes;

[0067] S111 , calculating the flight time difference variance of each group of echoes, and selecting the group of echoes with the smallest variance as the adjusted initial configuration.

[0068] See Figure 5 , is a schematic diagram of selecting data segments according to this embodiment of the present invention. In this embodiment, 15 waves are selected from the echoes. Ten waves are sequentially selected from these 15 waves each time as a group of echoes, ultimately obtaining a total of six groups of echoes A to F. The variance of the time-of-flight differences of these six groups of echoes is calculated, and the group of echoes with the smallest variance is selected as the adjusted initial configuration.

[0069] In this embodiment, n' waves are selected from the echo, and n waves are further selected from the n' waves. Under the same usage environment, the waveform of each echo of the transducer is roughly the same. By selecting a relatively stable waveform from one of the echoes to participate in the calculation of the flight time, it can adapt to different models of transducers, the deviation of the transducer itself and different pipe section structures. Preferably, the above process of selecting the optimal interference suppression configuration is completed by an automated software algorithm to automatically select the most appropriate calculation band, reduce the investment of manpower and material resources, and no longer need to spend a lot of time dealing with a few problematic meters, thereby improving the first-time production pass rate of smart ultrasonic water meters.

[0070] The operating environment includes the transducer, pipe structure and installation location, etc.

[0071] When an ultrasonic water meter is used in a real environment, it will not only be affected by interference from the hardware itself, but also by electromagnetic interference in the installation space, interference from the transducer's own accuracy, energy reflection interference caused by the pipe structure, and flow field disturbance interference, etc., resulting in poor accuracy and stability of the ultrasonic water meter. Existing ultrasonic water meters usually filter the obtained echoes. However, the traditional filtering method is a single filtering method, which has a poor filtering effect and can only reduce interference, which is not conducive to the accurate calculation of energy. Therefore, the present application scheme also provides a multi-stage filtering interference suppression method.

[0072] According to the different levels of interference the meter receives during the metering phase, it can be divided into mild interference, moderate interference and severe interference. Mild interference occurs for a very short time and only affects one or two waves in the echo that participate in the flight time calculation area. It will only make the volatility of the flight time difference worse, and will not have much impact on the flow error. The abnormal values ​​in these single echoes are filtered out through the first-level filter to reduce the volatility of the flight time difference and improve the metering stability. Moderate interference is, for example, when the flight time difference changes sharply when individual bubbles appear in the pipeline. This will cause a large offset in the overall data of a certain echo. The overall echo data with problems is filtered out through the second-level filter. The instantaneous flow velocity at multiple moments is calculated based on each echo during the second-level filtering. Severe interference refers to when a large number of bubbles appear in the pipeline. The second-level filter cannot completely filter out the interference data. The instantaneous flow velocity at the problem moment is filtered out through the third-level filter, which has a better suppression effect on the interference in space.

[0073] See Figure 6 , is a flow chart of the first stage filtering in the multi-stage filtering of this embodiment of the present invention. The first stage filtering in the multi-stage filtering includes:

[0074] Filter the time-of-flight difference of the echo at the current time m and calculate the variance of the filtered time-of-flight difference;

[0075] If the variance of the flight time difference is greater than or equal to the second preset threshold, the flight time difference at time m is discarded, and the flight time difference at time m-1 is used as the first-stage filtered flight time difference diff_ToF m ;

[0076] If the flight time difference variance is less than the second preset threshold, the flight time difference at time m is used as the first-stage filtered flight time difference diff_ToF m .

[0077] In the above-mentioned first-level filtering, if time m is used as the first sampling moment, and its flight time difference variance is greater than or equal to the second preset threshold, then there is no time m-1. The data of time m is directly discarded, and time m+1 is used as the first sampling moment of the new sampling. A total of n time data are collected.

[0078] By filtering out abnormal single echo data through the first stage filtering and filling the filtered abnormal data part with data from other moments, it can prevent the situation where the effective data samples obtained by filtering are too few, and accurate calculation results or even no results are obtained.

[0079] Then the filtered flight time difference is subjected to a second level of filtering, see Figure 7 , is a flow chart of the second stage filtering in the multi-stage filtering of this embodiment of the present invention. The second stage filtering in the multi-stage filtering includes:

[0080] S24, performing secondary filtering on the flight time differences at multiple moments to obtain secondary filtered flight time differences;

[0081] S25, calculating the instantaneous flow velocity at time m through the flight time difference of the secondary filter.

[0082] Specifically, starting from time m, the first-stage filtered flight time difference {diff_ToF m-X+1 , diff_ToF m-X+2 , ... , diff_ToF m}, remove the a maximum value and a minimum value and calculate the average value to get the second-stage filtered flight time difference and get the second-stage filtered flight time difference diff_ToF m ';

[0083] According to the second stage filtering flight time difference diff_ToF m 'Calculate the instantaneous flow velocity dV at time m m .

[0084] Calculate the instantaneous flow velocity dV at time m m The formula is:

[0085]

[0086] in, is the speed of sound, and L is the distance between the upstream and downstream ultrasonic transducers.

[0087] In this embodiment, common combinations of X / a are 8 / 1, 16 / 2, and 32 / 4. Those skilled in the art will appreciate that they can set appropriate values ​​according to actual needs. The abnormal flight time difference data calculated in the first stage of filtering is filtered out by the second stage of filtering, and the instantaneous flow velocity dV at time m is calculated. mSince the variance calculates the degree of data fluctuation, it is possible that the echoes at a certain moment will have the same degree of drift. In this case, the variance at this moment is less than the second preset threshold, but the calculated flight time difference is much different from that at other moments. The second-level filtering can filter out this data and improve the measurement accuracy.

[0088] Perform the third level filtering on the instantaneous flow velocity, including:

[0089] The instantaneous flow velocity {dV m-Y+1 , dV m-Y+2 , ... , dV m}, remove the b maximum values ​​and b minimum values ​​and calculate the average to obtain the filtered instantaneous flow velocity dV at time m (i.e., the current time).

[0090] In this embodiment, common combinations of Y / b are 8 / 1, 16 / 2 and 32 / 4. Those skilled in the art will appreciate that they can set appropriate values ​​according to actual needs. The abnormal instantaneous flow velocity dV calculated in the second stage filtering is filtered out by the third stage filtering. m The filtered instantaneous flow velocity dV is obtained.

[0091] The overall process of multi-stage filtering can be found in Figure 8 , which is a schematic diagram of the overall process of multi-stage filtering of this embodiment of the present invention. The specific process will not be repeated here. The application scheme filters the basic collected data through the first stage filtering, filters the flight time difference data through the second stage filtering, and filters the instantaneous flow velocity through the third stage filtering. The three stages of filtering work together to cope with interference of different severity and accurately calculate energy consumption.

[0092] Calculating flow rate and other related data through flow velocity is a conventional technical means in this field and does not constitute an innovation of the present application, so the description is omitted.

[0093] Another embodiment of the present application provides an ultrasonic water meter, the ultrasonic water meter of this embodiment comprising:

[0094] means for selecting an optimal interference suppression configuration based on echo information of upstream and downstream transducers at the same moment;

[0095] means for calculating a time-of-flight difference of an echo based on the optimal interference suppression configuration, filtering the time-of-flight difference, and obtaining a filtered time-of-flight difference;

[0096] means for calculating instantaneous flow velocity from said filtered time-of-flight difference.

[0097] The ultrasonic water meter can automatically select the optimal interference suppression configuration based on the installation space, the measurement pipe structure, and the transducer. The process of selecting the optimal interference suppression configuration includes:

[0098] The ultrasonic water meter collects and obtains echoes of upstream and downstream transducers at the same time, and selects default n continuous waves from the echoes according to the initial configuration;

[0099] Calculating a time-of-flight difference variance of the n consecutive waves, and if the time-of-flight difference variance is less than a first preset threshold, using an initial configuration as the optimal interference suppression configuration;

[0100] If the flight time difference variance is greater than or equal to the first preset threshold, the initial configuration is adjusted to obtain an adjusted initial configuration, and the adjusted initial configuration is used as the optimal interference suppression configuration.

[0101] An embodiment of the present application provides an ultrasonic water meter. Figure 9 , is a schematic diagram of an ultrasonic water meter according to an embodiment of the present invention, comprising: a data acquisition module 101, a data processing module 102 and a display module 103; wherein,

[0102] The data acquisition module 101 is used to acquire echoes;

[0103] The data processing module 102 is used to automatically select the optimal interference suppression configuration for different measurement pipe section structures and transducers;

[0104] The data processing module 102 is also used to perform multi-stage filtering and calculation on the echo data collected by the data collection module 101;

[0105] The display module 103 is used to display the data calculated by the data processing module 102 .

[0106] In other embodiments, it further includes: a data transmission module,

[0107] The data transmission module is used to upload the measured results to a server or concentrator and other devices for remote monitoring of the operation of the ultrasonic water meter and remote data collection.

[0108] Compared with the prior art, the solution of the present application selects the optimal interference suppression configuration according to different transducers and pipe section structures in actual application during the initialization phase, and is adaptable to most standard meters and a few problem meters. For most standard meters, by selecting the default n consecutive waves in the initial configuration, a stable echo area can be quickly obtained without affecting the use under normal circumstances; for a few problematic meters, a stable waveform is automatically selected from the echo through a software algorithm to participate in the calculation, and there is no need to debug the problematic meter separately, which improves the first-time production pass rate and reduces the investment of manpower and material resources; in the calculation stage, a multi-stage filtering method is used to filter the obtained flight time difference, and each stage of filtering processing is different to cope with the flight time difference data obtained under different interference severity. The single or several flight time difference data with a small proportion of abnormal values ​​are filtered through the first-stage filtering. If the proportion of abnormal values ​​is too large, the entire set of flight time difference data can be further filtered through the second-stage filtering, and the instantaneous flow velocity at the current moment is calculated. If the instantaneous flow velocity at a certain moment is abnormal, it can be further filtered through the third-stage filtering; the multi-stage filtering of the present invention can have a better suppression effect on bubble interference and electromagnetic interference of the meter.

[0109] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

[0110] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for suppressing interference in ultrasonic flow measurement, characterized in that: The following steps are involved: S1, selects the optimal interference suppression configuration based on the echo information of the upstream and downstream transducers at the same time; The process of selecting the optimal interference suppression configuration in step S1 includes: S11, acquiring echoes of upstream and downstream transducers at the same moment, and selecting default n consecutive waves from the echoes according to the initial configuration; S12, calculating the flight time difference variance of the n consecutive waves, and if the flight time difference variance is less than a first preset threshold, using the initial configuration as the optimal interference suppression configuration; S13: If the flight time difference variance is greater than or equal to the first preset threshold, adjust the initial configuration to obtain an adjusted initial configuration, and use the adjusted initial configuration as the optimal interference suppression configuration; The process of adjusting the initial configuration in step S13 includes: S131, the ultrasonic water meter collects and obtains echoes from the upstream and downstream transducers at the same time, selects n' waves from the echoes, where n'>n, and sequentially selects n waves from the n' waves to form a group of echoes to obtain multiple groups of echoes; S132, calculating the flight time difference variance of each group of echoes, and selecting the group of echoes with the smallest variance as the adjusted initial configuration; S2, calculating the time-of-flight difference of the echo based on the optimal interference suppression configuration, performing multi-stage filtering on the time-of-flight difference to obtain a filtered time-of-flight difference, and calculating the instantaneous flow velocity at the current moment based on the filtered time-of-flight difference; S3, calculating the filtered instantaneous flow velocity at the current moment by using the instantaneous flow velocities at multiple moments including the current moment.

2. The interference suppression method for ultrasonic flow measurement according to claim 1, characterized in that: The first stage of filtering in the multi-stage filtering includes: S21, filtering the time-of-flight difference of the echo at the current time m, and calculating the variance of the filtered time-of-flight difference; S22: If the flight time difference variance is greater than or equal to the second preset threshold, the flight time difference at time m is discarded, and the flight time difference at time m-1 is used as the first-stage filtered flight time difference diff_ToF. m ; S23, if the flight time difference variance is less than the second preset threshold, the flight time difference at time m is used as the first-stage filtered flight time difference diff_ToF m .

3. The interference suppression method for ultrasonic flow measurement according to claim 2, characterized in that: The second stage filtering in the multi-stage filtering includes: S24, starting from time m, collects the first-stage filtered flight time difference {diff_ToF m-X+1 ,diff_ToF m-X+2 , ... , diff_ToF m }, remove the a maximum value and a minimum value and calculate the average value to get the second-stage filtered flight time difference diff_ToF m '; S25, filtering the time of flight difference diff_ToF according to the second stage m 'Calculate the instantaneous flow velocity dV at time m m .

4. The interference suppression method for ultrasonic flow measurement according to claim 1, characterized in that: The filtered instantaneous flow velocity at the current moment calculated in step S3 includes: S26, starting from time m, collect the instantaneous flow velocity {dV m-Y+1 , dV m-Y+2 , ... , dV m }, remove the b maximum values ​​and b minimum values ​​and calculate the average to obtain the filtered instantaneous flow velocity dV at time m, where dV is the filtered instantaneous flow velocity at the current moment.

5. An ultrasonic water meter, characterized in that: Ultrasonic flow measurement is performed using the interference suppression method for ultrasonic flow measurement as described in any one of claims 1 to 4.

6. A computer-readable storage medium storing an executable computer program, characterized in that: When the computer program is executed, the interference suppression method for ultrasonic flow measurement as claimed in any one of claims 1 to 4 is completed.

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