CN114777887A - Zero drift elimination method for ultrasonic water meter - Google Patents

Zero drift elimination method for ultrasonic water meter Download PDF

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CN114777887A
CN114777887A CN202210550105.9A CN202210550105A CN114777887A CN 114777887 A CN114777887 A CN 114777887A CN 202210550105 A CN202210550105 A CN 202210550105A CN 114777887 A CN114777887 A CN 114777887A
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water meter
ultrasonic
ultrasonic water
reading
pipeline
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谷凤
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Hefei Yuanchi Information Technology Co ltd
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/66Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters

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Abstract

The invention relates to an ultrasonic water meter, in particular to a zero drift elimination method of an ultrasonic water meter, which comprises the steps of obtaining the forward propagation time of ultrasonic waves of the ultrasonic water meter in a zero flow state and the corresponding reverse propagation time, and calculating to obtain a plurality of groups of forward and reverse propagation time differences; obtaining a fluctuation interval based on the multiple groups of forward and reverse propagation time differences, and determining a first compensation value of the ultrasonic water meter based on the fluctuation interval; installing an ultrasonic water meter in a pipeline, and respectively installing a first standard flowmeter and a second standard flowmeter at the upstream and the downstream of the pipeline; performing error testing, calculating reading errors among the ultrasonic water meter, the first standard flowmeter and the second standard flowmeter, and determining a second compensation value of the ultrasonic water meter based on the reading errors; the technical scheme provided by the invention can effectively overcome the defect that the zero drift of the ultrasonic water meter can not be effectively eliminated because the accurate compensation value can not be obtained in the prior art.

Description

Zero drift elimination method for ultrasonic water meter
Technical Field
The invention relates to an ultrasonic water meter, in particular to a zero drift elimination method of an ultrasonic water meter.
Background
The zero drift is a phenomenon that the ultrasonic water meter is self-propelled due to self reasons or under the condition of interference of other external factors after the ultrasonic water meter is calibrated.
At present, the range ratio of the existing ultrasonic water meter is higher and higher, the precision requirements on a chip and a transducer are also higher and higher, however, after the chip is matched with the transducer, the acquired time value always fluctuates to a certain extent, and the fluctuation quantity is not negligible relative to the initial flow. The existing algorithm directly adds the measured value into the calculation, so that the self-walking phenomenon of the water meter, namely the zero drift, is likely to occur within a certain time.
Because the low initial motion and the zero drift of the ultrasonic wave are originally a pair of contradictions, and the fluctuation of the time value measured by the matching of the transducer and the chip cannot be effectively controlled, one mode is to reduce the range ratio of the ultrasonic water meter and improve the initial motion; another way is to eliminate the fluctuation amount in a short time.
In order to improve the stability of the water meter and ensure the accuracy in the measuring range, the water meter is required to have a compensation value, the zero point measurement of the water meter is originally a fluctuation value, and only a reasonable range needs to be set, and a sudden change is removed during the zero point measurement, so that the water meter can be kept in a stable state. However, the zero drift elimination method of the existing ultrasonic water meter cannot obtain an accurate compensation value, so that the zero drift of the ultrasonic water meter cannot be effectively eliminated.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects in the prior art, the invention provides a zero drift elimination method for an ultrasonic water meter, which can effectively overcome the defect that the zero drift of the ultrasonic water meter cannot be effectively eliminated because an accurate compensation value cannot be obtained in the prior art.
(II) technical scheme
In order to realize the purpose, the invention is realized by the following technical scheme:
a zero drift elimination method of an ultrasonic water meter comprises the following steps:
s1, acquiring the forward propagation time of the ultrasonic wave of the ultrasonic water meter in a zero-flow state and the corresponding reverse propagation time, and calculating to obtain a plurality of groups of forward and reverse propagation time differences;
s2, obtaining a fluctuation interval based on the multiple groups of forward and backward propagation time differences, and determining a first compensation value of the ultrasonic water meter based on the fluctuation interval;
s3, installing the ultrasonic water meter in a pipeline, and respectively installing a first standard flowmeter and a second standard flowmeter at the upstream and downstream of the pipeline;
s4, carrying out error testing, calculating reading errors among the ultrasonic water meter, the first standard flowmeter and the second standard flowmeter, and determining a second compensation value of the ultrasonic water meter based on the reading errors;
and S5, determining a final compensation value of the ultrasonic water meter by integrating the first compensation value and the second compensation value, and eliminating zero drift of the ultrasonic water meter by using the final compensation value.
Preferably, the step S2 of obtaining the fluctuation interval based on the sets of forward and backward propagation time differences and determining the first compensation value of the ultrasonic water meter based on the fluctuation interval includes:
obtaining the forward and reverse propagation time difference value with the largest occurrence number in the fluctuation interval according to the normal distribution of the multiple groups of forward and reverse propagation time differences, and determining a first compensation value lambda of the ultrasonic water meter according to the forward and reverse propagation time difference value1
Preferably, before acquiring the forward propagation time of the ultrasonic wave of the ultrasonic water meter in the zero-flow state and the corresponding backward propagation time in S1, the method includes:
and calibrating the ultrasonic pulse width ratio output by the ultrasonic water meter so that the ultrasonic pulse width ratio is within a set range.
Preferably, the calibrating the ultrasonic pulse width ratio output by the ultrasonic water meter so that the ultrasonic pulse width ratio is within a set range includes:
acquiring an ultrasonic sine output curve of the ultrasonic water meter, determining a reference line based on an initial threshold of ultrasonic output, and judging whether the pulse width ratio of the ultrasonic sine output curve corresponding to the reference line and a transverse axis in each sine period is in a set range or not;
if the pulse width ratio is in the set range, the ultrasonic pulse width ratio meets the requirement, otherwise, the ultrasonic pulse width ratio is adjusted to be in the set range.
Preferably, the adjusting the ultrasonic pulse width ratio value to a set range includes:
the initial threshold value of the ultrasonic output is adjusted, or the ultrasonic sine output curve is adjusted until the ultrasonic pulse width ratio is in the set range.
Preferably, the set range is such that the pulse width ratio of the ultrasonic sinusoidal output curve in each sinusoidal period to the reference line and the horizontal axis is 75% to 85%.
Preferably, in S3, the ultrasonic water meter is installed in the pipeline, and the first standard flowmeter and the second standard flowmeter are respectively installed at the upstream and the downstream of the pipeline, and the method includes:
closing an upstream valve of the pipeline, emptying tap water in the pipeline, and simultaneously emptying the ultrasonic water meter and air in the pipeline;
and (3) checking and calibrating the two external clamp type ultrasonic flow meters which are respectively used as a first standard flow meter and a second standard flow meter and are correspondingly arranged at the upstream and the downstream of the pipeline.
Preferably, an error test is performed in S4, including:
reading the initial reading of the ultrasonic water meter, opening a valve at the upstream of the pipeline to drain water, and collecting the discharged tap water by using a container;
closing an upstream valve of the pipeline, respectively reading the readings of the first standard flowmeter and the second standard flowmeter after tap water in the pipeline is drained, and taking the average as the reading f of the standard flowmetera
And reading the current reading of the ultrasonic wave, and taking the difference value of the current reading and the initial reading as the reading f of the ultrasonic water meter.
Preferably, the step of calculating reading errors between the ultrasonic water meter and the first standard flow meter and the second standard flow meter in step S4 and determining a second compensation value of the ultrasonic water meter based on the reading errors comprises:
calculating the reading f of the ultrasonic water meter and the reading f of the standard flowmeter by the following formulaaThe error between:
Figure BDA0003654630510000041
carrying out multiple error tests, and calculating to obtain the average error delta of the multiple error testsa
Calculating a calibration reading f' for the ultrasonic water meter by:
Figure BDA0003654630510000042
calculating a second compensation value lambda of the ultrasonic water meter by the following formula2
Figure BDA0003654630510000043
(III) advantageous effects
Compared with the prior art, the zero drift elimination method of the ultrasonic water meter provided by the invention comprises the steps of firstly obtaining the forward propagation time and the corresponding reverse propagation time of the ultrasonic water meter in a zero-flow state, calculating to obtain multiple groups of forward and reverse propagation time differences, obtaining a fluctuation interval based on the multiple groups of forward and reverse propagation time differences, and determining a first compensation value of the ultrasonic water meter based on the fluctuation interval; and secondly, performing error testing, calculating reading errors among the ultrasonic water meter, the first standard flowmeter and the second standard flowmeter, determining a second compensation value of the ultrasonic water meter based on the reading errors, and synthesizing the first compensation value and the second compensation value to obtain an accurate final compensation value of the ultrasonic water meter, thereby effectively eliminating zero drift of the ultrasonic water meter.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a schematic view of a process for determining a first compensation value of an ultrasonic water meter according to the present invention;
fig. 3 is a schematic flow chart of determining a second compensation value of the ultrasonic water meter according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
A zero drift elimination method for an ultrasonic water meter is disclosed, as shown in fig. 1 and fig. 2, firstly, the forward propagation time and the corresponding reverse propagation time of the ultrasonic water meter in a zero flow state are obtained, and a plurality of groups of forward and reverse propagation time differences are obtained through calculation.
Wherein, before obtaining ultrasonic wave forward propagation time of ultrasonic water meter under zero flow state to and the reverse propagation time that corresponds, include:
and calibrating the ultrasonic pulse width ratio output by the ultrasonic water meter, so that the ultrasonic pulse width ratio is in a set range.
Wherein, the ultrasonic wave pulse width ratio of calibration ultrasonic water meter output for this ultrasonic wave pulse width ratio lies in the settlement within range, includes:
acquiring an ultrasonic sine output curve of the ultrasonic water meter, determining a reference line based on an initial threshold of ultrasonic output, and judging whether the pulse width ratio of the ultrasonic sine output curve corresponding to the reference line and a transverse axis in each sine period is in a set range or not;
if the pulse width ratio is in the set range, the ultrasonic pulse width ratio meets the requirement, otherwise, the ultrasonic pulse width ratio is adjusted to be in the set range.
Wherein, adjust this ultrasonic wave pulse width ratio to the settlement within range, include:
the initial threshold value of the ultrasonic output is adjusted, or the ultrasonic sine output curve is adjusted until the ultrasonic pulse width ratio is in the set range.
In the technical scheme of the application, the setting range is that the pulse width ratio of the ultrasonic sine output curve in each sine period to the reference line and the horizontal axis respectively is 75-85%.
Obtaining a fluctuation interval based on the multiple groups of forward and backward propagation time differences, and determining a first compensation value of the ultrasonic water meter based on the fluctuation interval, wherein the method specifically comprises the following steps:
obtaining the forward and reverse propagation time difference value with the most occurrence times in the fluctuation interval according to the normal distribution of the multiple groups of forward and reverse propagation time differences, and determining a first compensation value lambda of the ultrasonic water meter according to the forward and reverse propagation time difference value1
Through the technical scheme, the first compensation value of the ultrasonic water meter can be accurately obtained based on the multiple groups of forward and backward propagation time differences of the ultrasonic water meter under the zero flow state.
As shown in fig. 1 and 3, the third step of installing the ultrasonic water meter in the pipeline, and installing the first standard flowmeter and the second standard flowmeter at the upstream and downstream of the pipeline respectively includes:
closing an upstream valve of the pipeline, emptying tap water in the pipeline, and simultaneously emptying the ultrasonic water meter and air in the pipeline;
and (3) checking and calibrating the two external clamp type ultrasonic flow meters, wherein the two external clamp type ultrasonic flow meters are respectively used as a first standard flow meter and a second standard flow meter and are correspondingly arranged at the upstream and the downstream of the pipeline.
And fourthly, performing error test, calculating reading errors among the ultrasonic water meter, the first standard flowmeter and the second standard flowmeter, and determining a second compensation value of the ultrasonic water meter based on the reading errors.
Wherein, carry out error test, include:
reading an initial reading of the ultrasonic water meter, opening a valve at the upstream of a pipeline to drain, and collecting discharged tap water by using a container;
closing an upstream valve of the pipeline, and respectively reading the first standard flowmeter and the second standard flowmeter after tap water in the pipeline is emptiedAnd taking the average as the reading f of the standard flowmetera
And reading the current reading of the ultrasonic wave, and taking the difference value of the current reading and the initial reading as the reading f of the ultrasonic water meter.
Wherein, calculate the reading error between ultrasonic water meter and first standard flowmeter, second standard flowmeter to based on reading error confirm the second offset value of ultrasonic water meter, include:
calculating the reading f of the ultrasonic water meter and the reading f of the standard flowmeter by the following formulaaThe error between:
Figure BDA0003654630510000071
carrying out multiple error tests, and calculating to obtain the average error delta of the multiple error testsa
Calculating a calibration reading f' for the ultrasonic water meter by:
Figure BDA0003654630510000072
calculating a second compensation value lambda of the ultrasonic water meter by the following formula2
Figure BDA0003654630510000073
Through the technical scheme, the ultrasonic water meter, the first standard flowmeter and the second standard flowmeter are installed in the pipeline, and after error testing is carried out, the second compensation value of the ultrasonic water meter can be accurately obtained.
And fifthly, determining the final compensation value of the ultrasonic water meter by integrating the first compensation value and the second compensation value, and eliminating the zero drift of the ultrasonic water meter by using the final compensation value.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims (9)

1. A zero drift elimination method of an ultrasonic water meter is characterized by comprising the following steps: the method comprises the following steps:
s1, acquiring the forward propagation time of the ultrasonic wave of the ultrasonic water meter in a zero-flow state and the corresponding reverse propagation time, and calculating to obtain a plurality of groups of forward and reverse propagation time differences;
s2, obtaining a fluctuation interval based on the multiple groups of forward and backward propagation time differences, and determining a first compensation value of the ultrasonic water meter based on the fluctuation interval;
s3, installing the ultrasonic water meter in a pipeline, and respectively installing a first standard flowmeter and a second standard flowmeter at the upstream and downstream of the pipeline;
s4, carrying out error test, calculating reading errors among the ultrasonic water meter, the first standard flowmeter and the second standard flowmeter, and determining a second compensation value of the ultrasonic water meter based on the reading errors;
and S5, determining a final compensation value of the ultrasonic water meter by integrating the first compensation value and the second compensation value, and eliminating zero drift of the ultrasonic water meter by using the final compensation value.
2. The method for eliminating zero drift of an ultrasonic water meter according to claim 1, wherein: in S2, obtaining a fluctuation interval based on the multiple sets of forward and backward propagation time differences, and determining a first compensation value of the ultrasonic water meter based on the fluctuation interval, including:
obtaining the forward and reverse propagation time difference value with the largest occurrence number in the fluctuation interval according to the normal distribution of the multiple groups of forward and reverse propagation time differences, and determining a first compensation value lambda of the ultrasonic water meter according to the forward and reverse propagation time difference value1
3. The method for eliminating zero drift of an ultrasonic water meter according to claim 1, wherein: in S1, before the ultrasonic forward propagation time of the ultrasonic water meter in the zero-flow state and the corresponding backward propagation time are obtained, the method includes:
and calibrating the ultrasonic pulse width ratio output by the ultrasonic water meter, so that the ultrasonic pulse width ratio is in a set range.
4. The zero drift elimination method for an ultrasonic water meter according to claim 3, wherein: the ultrasonic wave pulse width ratio of calibration ultrasonic water meter output for this ultrasonic wave pulse width ratio lies in the settlement within range, includes:
acquiring an ultrasonic sine output curve of the ultrasonic water meter, determining a reference line based on an initial threshold value of ultrasonic output, and judging whether the pulse width ratio of the ultrasonic sine output curve in each sine period corresponding to the reference line and a transverse axis is within a set range;
if the pulse width ratio is in the set range, the ultrasonic pulse width ratio meets the requirement, otherwise, the ultrasonic pulse width ratio is adjusted to be in the set range.
5. The zero drift elimination method for an ultrasonic water meter according to claim 4, wherein: the ultrasonic pulse width ratio is adjusted to a set range, and the method comprises the following steps:
the initial threshold value of the ultrasonic output is adjusted, or the ultrasonic sine output curve is adjusted until the ultrasonic pulse width ratio is within the set range.
6. The zero drift elimination method for an ultrasonic water meter according to claim 5, wherein: the set range is that the pulse width ratio of the ultrasonic sine output curve in each sine period to the reference line and the horizontal axis respectively is 75-85%.
7. The zero drift elimination method for an ultrasonic water meter according to claim 1, characterized in that: in S3, the ultrasonic water meter is installed in a pipeline, and a first standard flowmeter and a second standard flowmeter are respectively installed at the upstream and the downstream of the pipeline, and the ultrasonic water meter installation method includes:
closing an upstream valve of the pipeline, emptying tap water in the pipeline, and simultaneously emptying the ultrasonic water meter and air in the pipeline;
and (3) checking and calibrating the two external clamp type ultrasonic flow meters, wherein the two external clamp type ultrasonic flow meters are respectively used as a first standard flow meter and a second standard flow meter and are correspondingly arranged at the upstream and the downstream of the pipeline.
8. The zero drift elimination method for an ultrasonic water meter according to claim 7, wherein: performing an error test in S4, including:
reading an initial reading of the ultrasonic water meter, opening a valve at the upstream of a pipeline to drain, and collecting discharged tap water by using a container;
closing an upstream valve of the pipeline, respectively reading readings of the first standard flowmeter and the second standard flowmeter after tap water in the pipeline is emptied, and taking the average number as the reading f of the standard flowmetera
And reading the current reading of the ultrasonic wave, and taking the difference value of the current reading and the initial reading as the reading f of the ultrasonic water meter.
9. The method for eliminating zero drift of an ultrasonic water meter according to claim 8, wherein: in S4, calculating reading errors between the ultrasonic water meter and the first standard flow meter and the second standard flow meter, and determining a second compensation value of the ultrasonic water meter based on the reading errors, including:
calculating the reading f of the ultrasonic water meter and the reading f of the standard flowmeter by the following formulaaThe error between:
Figure FDA0003654630500000031
carrying out multiple error tests, and calculating to obtain average error delta of multiple error testsa
Calculating a calibration reading f' for the ultrasonic water meter by:
Figure FDA0003654630500000032
calculating a second compensation value lambda of the ultrasonic water meter by the following formula2
Figure FDA0003654630500000033
CN202210550105.9A 2022-05-20 2022-05-20 Zero drift elimination method for ultrasonic water meter Pending CN114777887A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115727909A (en) * 2022-11-29 2023-03-03 青岛鼎信通讯科技有限公司 Method for reducing zero drift of ultrasonic water meter
CN116625444A (en) * 2023-03-13 2023-08-22 宁夏隆基宁光仪表股份有限公司 Method for self-adapting characteristic wave and flow correction of ultrasonic water meter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115727909A (en) * 2022-11-29 2023-03-03 青岛鼎信通讯科技有限公司 Method for reducing zero drift of ultrasonic water meter
CN116625444A (en) * 2023-03-13 2023-08-22 宁夏隆基宁光仪表股份有限公司 Method for self-adapting characteristic wave and flow correction of ultrasonic water meter

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