CN104236646A - Ultrasonic flowmeter and ultrasonic flow measuring method - Google Patents
Ultrasonic flowmeter and ultrasonic flow measuring method Download PDFInfo
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- CN104236646A CN104236646A CN201310308284.6A CN201310308284A CN104236646A CN 104236646 A CN104236646 A CN 104236646A CN 201310308284 A CN201310308284 A CN 201310308284A CN 104236646 A CN104236646 A CN 104236646A
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- 238000000034 method Methods 0.000 title claims abstract description 20
- 238000012545 processing Methods 0.000 claims abstract description 31
- 238000001514 detection method Methods 0.000 claims abstract description 13
- 238000001914 filtration Methods 0.000 claims description 10
- 239000000523 sample Substances 0.000 claims description 10
- 238000003491 array Methods 0.000 claims description 5
- KTEXNACQROZXEV-PVLRGYAZSA-N parthenolide Chemical compound C1CC(/C)=C/CC[C@@]2(C)O[C@@H]2[C@H]2OC(=O)C(=C)[C@@H]21 KTEXNACQROZXEV-PVLRGYAZSA-N 0.000 description 10
- 238000010586 diagram Methods 0.000 description 6
- 238000004891 communication Methods 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000012535 impurity Substances 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Abstract
The invention discloses an ultrasonic flowmeter and an ultrasonic flow measuring method. The ultrasonic flowmeter includes a zero point detection circuit and an arithmetic processing circuit. The zero detection circuit comprises a digital-analog converter, a pre-trigger comparator, a zero cross comparator and an AND gate. The digital-to-analog converter generates a multi-stage trigger signal. The pre-trigger comparator compares the ultrasonic echo with the multi-stage trigger signal to output a first comparison signal. The zero-crossing comparator compares the ultrasonic echo with a reference level to output a second comparison signal. The AND gate performs an intersection operation on the first comparison signal and the second comparison signal to output a zero-crossing digital signal. The arithmetic processing circuit calculates the ultrasonic flow rate from the zero-crossing digital signal.
Description
Technical field
The present invention relates to a kind of ultrasonic flow and take into account ultrasonic flow measuring method.
Background technology
Ultrasonic flow meter group can be installed on pipeline surface, does not need to excise pipeline and can measure flow in pipeline, or be installed on direct measuring flow on pipeline.Ultrasonic flow meter is mainly used to measure clean uniform fluid flow, in oil, chemical industry, metallurgy, electric power, Running-water Company and process water and river, recycle-water field, be used widely, in addition ultrasonic flow meter can measure the not high uniform fluid of impurity content, as the flow of the media such as sewage, if having bubble or the larger solids of volume in pipe, cannot measure.
Tradition transit-time ultrasonic flow meter need to be used alone one group of peak detection circuit to judge the intensity of ultrasonic echo, then the intensity of ultrasonic echo is supplied to gain control circuit do waveform amplify FEEDBACK CONTROL.Then utilize the first wave of ultrasonic echo, judge the ultrasound wave flight time with zero crossings testing circuit.But, traditional transit-time ultrasonic flow meter because only detect a first wave zero crossings, so easily because the disturbing effect measurement accuracy such as bubble, impurity in fluid.
Summary of the invention
The present invention relates to a kind of ultrasonic flow and take into account ultrasonic flow measuring method.
According to the present invention, a kind of ultrasonic flow meter is proposed.Ultrasonic flow meter comprises zero-detection circuit and arithmetic processing circuit.Zero-detection circuit comprise digital analog converter, pre-trigger comparer, zero crossings comparer and with door (AND gate).Digital analog converter produces a multistage trigger pip.Pre-trigger comparer compares ultrasonic echo and multistage trigger pip to export the first comparison signal.Zero crossings comparer compares ultrasonic echo and datum to export the second comparison signal.An intersection operation is carried out to export a zero crossing (Zero-cross) digital signal with goalkeeper first comparison signal and the second comparison signal.Arithmetic processing circuit calculates ultrasonic flow according to zero crossing digital signal.
According to the present invention, a kind of ultrasonic flow measuring method is proposed.Ultrasonic flow measuring method comprises: produce multistage trigger pip; Ultrasonic echo and this multistage trigger pip is compared to export the first comparison signal by pre-trigger comparer; Ultrasonic echo and datum is compared to export the second comparison signal by zero crossings comparer; First comparison signal and the second comparison signal are carried out an intersection operation to export a zero crossing (Zero-cross) digital signal; And calculate ultrasonic flow according to zero crossing digital signal.
Accompanying drawing explanation
Fig. 1 is a kind of embodiment circuit box schematic diagram of ultrasonic flow meter;
Fig. 2 is the schematic diagram of zero-detection circuit;
Fig. 3 is the sequential chart of ultrasonic echo, the first comparison signal, the second comparison signal, zero crossing digital signal;
Fig. 4 is the schematic diagram of multistage trigger pip and ultrasonic echo;
Fig. 5 is the numeric distribution figure of the zero crossing time array of non-filtered calculation;
Fig. 6 is the numeric distribution figure of the filtered data through filtering calculation.
[description of reference numerals]
1: ultrasonic flow meter
11a, 11b: ultrasonic probe
12a, 12b: driver
13a, 13b: switch
14: bandpass filter
15: variable gain amplifier
16: zero-detection circuit
17: arithmetic processing circuit
18: time measuring circuit
19: wireless communication module
161: digital analog converter
162: pre-trigger comparer
163: zero crossings comparer
164: with door
165: Sheffer stroke gate
PTL (1) ~ PTL (M): pre-trigger level
MS: multistage trigger pip
Rx: ultrasonic echo
Rst: reset signal
C1: the first comparison signal
C2: the second comparison signal
Ny: noise
L: latch-up signal
ZCD: zero crossing digital signal
ZC (1): pre-trigger word pulse
ZC (2): zero crossing digit pulse
SP: initial pulse
Embodiment
For making the object, technical solutions and advantages of the present invention clearly understand, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in further detail.
Please refer to Fig. 1, Fig. 1 is a kind of embodiment circuit box schematic diagram of ultrasonic flow meter.Ultrasonic flow meter 1 comprises ultrasonic probe 11a, ultrasonic probe 11b, driver 12a, driver 12b, switch 13a, switch 13b, bandpass filter 14, variable gain amplifier 15, zero-detection circuit 16, arithmetic processing circuit 17, time measuring circuit 18 and wireless communication module 19.Driver 12a is in order to drive ultrasonic probe 11a, and driver 12b is in order to drive ultrasonic probe 11b.Ultrasonic probe 11a and ultrasonic probe 11b alternately launches ultrasound wave and receives ultrasonic echo.
When switch 13a conducting, switch 13b ends accordingly.On the contrary, when switch 13a ends, switch 13b conducting accordingly.Bandpass filter 14 is in order to by the noise filtering beyond ultrasonic frequency range.Zero-detection circuit 16 is exported to after the ultrasonic echo that variable gain amplifier 15 receives according to feedback signal adjustment.Time measuring circuit 18 calculates the overtime time.Wireless communication module 19 is in order to transmitting/receiving wireless signal.Arithmetic processing circuit 17 is such as microcontroller, and wireless communication module 19 is such as ZigBee module.
Referring to Fig. 1, Fig. 2 and Fig. 3, Fig. 2 is the schematic diagram of zero-detection circuit, and Fig. 3 is the sequential chart of ultrasonic echo, the first comparison signal, the second comparison signal, zero crossing digital signal.Zero-detection circuit 16 comprise digital analog converter 161, pre-trigger comparer 162, zero crossings comparer 163, with door (AND gate) 164 and Sheffer stroke gate (NAND gate) 165.Arithmetic processing circuit 17 control figure analog converter 161 produces multistage trigger pip MS.Pre-trigger comparer 162 compares ultrasonic echo and Rx and multistage trigger pip MS to export the first comparison signal C1.Zero crossings comparer 163 compares ultrasonic echo Rx and a datum to export the second comparison signal C2.Datum is such as earth level.With door 164, first comparison signal C1 and the second comparison signal C2 is carried out an intersection operation to export zero crossing digital signal ZCD.Zero crossing digital signal ZCD comprises adjacent pre-trigger word pulse ZC (1) and zero crossing digit pulse ZC (2), pre-trigger word pulse ZC (1) produces at first, and zero crossing digit pulse ZC (2) is closest to pre-trigger word pulse ZC (1).The reset signal Rst that first comparison signal C1 and arithmetic processing circuit 17 export is carried out a reciprocal cross set operation to produce a latch-up signal L by Sheffer stroke gate 165, and latch-up signal L controls the latch mode of pre-trigger comparer 162.Arithmetic processing circuit 17 calculates ultrasonic flow according to zero crossing digital signal ZCD.Because the first comparison signal C1 and the second comparison signal C2 occurs simultaneously and obtains by the zero crossing digital signal ZCD exported with door 164, therefore the judgement of mistake by noise Ny affects can be avoided.
Furthermore, arithmetic processing circuit 17 selects zero crossing digit pulse ZC (2) as the end pulse calculating flight time TOF.Arithmetic processing circuit 17 calculates according to zero crossing digit pulse ZC (2) mistiming that flight time TOF, flight time TOF are initial pulse SP and zero crossing digit pulse ZC (2).Arithmetic processing circuit 17 is again according to the flight time TOF mathematic interpolation ultrasonic flow that two groups of ultrasonic probes replace.
Referring to Fig. 1, Fig. 3 and Fig. 4, Fig. 4 is the schematic diagram of multistage trigger pip and ultrasonic echo.Multistage trigger pip MS comprises pre-trigger level PTL (1) ~ PTL (M), and M be greater than 1 positive integer.Pre-trigger level PTL (1) ~ PTL (M) sequentially produces, and pre-trigger level PTL (1) ~ PTL (M) sequentially increases progressively.For example, pre-trigger level PTL (1) ~ PTL (M) sequentially increases progressively 15mV.When pre-trigger level PTL (M) equals 3000mV, then M etc. 200.
Arithmetic processing circuit 17 produces several zero crossing time array corresponding respectively to pre-trigger level PTL (1) ~ PTL (M) according to zero crossing digital signal ZCD.All zero crossing time arrays are first carried out a filtering operation by arithmetic processing circuit 17, and to produce a filtered data, arithmetic processing circuit 17 calculates ultrasonic flow according to filtered data again.Aforementioned filtering operation is such as a median average filter computing.The computing of median average filter first samples stored in array after N data, then array is done size sequence.Get median afterwards, then median two side data and median are subtracted each other.And then, judge whether the result after subtracting each other is less than allowable error value.Then stop when the result after subtracting each other is less than allowable error value.Then note down address A and B of array two end, then the value of array x (A) to x (B) is done average computation, the value obtained is filtered data.
In addition, arithmetic processing circuit 17 can also calculate the peak swing of ultrasonic echo Rx according to pre-trigger word pulse ZC (1), and using the feedback signal of peak swing as variable gain amplifier 15.Pre-trigger level PTL (1) ~ PTL (M) comprises adjacent pre-trigger level PTL (M-1) and pre-trigger level PTL (M), and pre-trigger level PTL (M) is greater than pre-trigger level PTL (M-1).When multistage trigger pip MS equals pre-trigger level PTL (M-1), arithmetic processing circuit 17 receives pre-trigger word pulse ZC (1) within the overtime time.Relatively, when multistage trigger pip MS equals pre-trigger level PTL (M), arithmetic processing circuit 17 cannot receive pre-trigger word pulse ZC (1) within the overtime time.Arithmetic processing circuit 17 selects pre-trigger level PTL (M-1) as peak swing.
Referring to the numeric distribution figure that the numeric distribution figure that Fig. 5 and Fig. 6, Fig. 5 are the zero crossing time array that non-filtered is calculated, Fig. 6 are the filtered data through filtering calculation.For example, use three inch PVC, fluid is static tap water and sampled data is 828.Standard deviation average out to 61ns as seen from Figure 5 before non-filtered calculation.Relatively, the standard deviation average out to 0.24ns as seen from Figure 6 after filtering calculation, reduces the amplitude that numerical value is beated significantly.
Above-described specific embodiment; object of the present invention, technical scheme and beneficial effect are further described; be understood that; the foregoing is only specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (20)
1. a ultrasonic flow meter, comprising:
One zero-detection circuit, comprising:
One digital analog converter, in order to produce a multistage trigger pip;
One pre-trigger comparer, in order to compare a ultrasonic echo and this multistage trigger pip to export one first comparison signal;
One zero crossings comparer, in order to compare this ultrasonic echo and a datum to export one second comparison signal; And
One with door (AND gate), in order to this first comparison signal and this second comparison signal are carried out an intersection operation to export a zero crossing (Zero-cross) digital signal; And
One arithmetic processing circuit, in order to calculate a ultrasonic flow according to this zero crossing digital signal.
2. ultrasonic flow meter as claimed in claim 1, it is characterized in that, this zero-detection circuit also comprises a Sheffer stroke gate (NAND gate), in order to this first comparison signal and a reset signal are carried out a reciprocal cross set operation to produce a latch-up signal, this latch-up signal controls the latch mode of this pre-trigger comparer.
3. ultrasonic flow meter as claimed in claim 1, it is characterized in that, this multistage trigger pip comprises multiple pre-trigger level, those pre-trigger level sequentially produce, and those pre-trigger level sequentially increase progressively, this zero crossing digital signal comprises an adjacent pre-trigger word pulse and a zero crossing digit pulse, and this pre-trigger word pulse produces at first, and this zero crossing digit pulse is closest to this pre-trigger word pulse.
4. ultrasonic flow meter as claimed in claim 3, it is characterized in that, this arithmetic processing circuit calculates a flight time according to this zero crossing digit pulse, and the flight time difference that this arithmetic processing circuit replaces according to two groups of ultrasonic probes calculates this ultrasonic flow.
5. ultrasonic flow meter as claimed in claim 3, it is characterized in that, this arithmetic processing circuit calculates a peak swing of this ultrasonic echo according to this pre-trigger word pulse.
6. ultrasonic flow meter as claimed in claim 5, is characterized in that, also comprise:
One variable gain amplifier, this arithmetic processing circuit is using the feedback signal of this peak swing as this variable gain amplifier.
7. ultrasonic flow meter as claimed in claim 5, is characterized in that, also comprise:
One time measuring circuit, in order to calculate the overtime time, those pre-trigger level comprise one first adjacent pre-trigger level and one second pre-trigger level, and this second pre-trigger level is greater than this first pre-trigger level, when this multistage trigger pip equals this first pre-trigger level, this arithmetic processing circuit receives this pre-trigger word pulse within this overtime time, when this multistage trigger pip equals this second pre-trigger level, this arithmetic processing circuit cannot receive this pre-trigger word pulse within this overtime time, this arithmetic processing circuit selects this first pre-trigger level as this peak swing.
8. ultrasonic flow meter as claimed in claim 3, it is characterized in that, this arithmetic processing circuit produces multiple zero crossing time array according to this zero crossing digital signal, and those zero crossing time arrays correspond respectively to those pre-trigger level.
9. ultrasonic flow meter as claimed in claim 8, it is characterized in that, those zero crossing time arrays are carried out a filtering operation by this arithmetic processing circuit, and to produce a filtered data, this arithmetic processing circuit calculates this ultrasonic flow according to this filtered data.
10. ultrasonic flow meter as claimed in claim 8, it is characterized in that, this filtering operation is a median average filter computing.
11. 1 kinds of ultrasonic flow measuring methods, comprising:
Produce a multistage trigger pip;
A ultrasonic echo and this multistage trigger pip is compared to export one first comparison signal by a pre-trigger comparer;
This ultrasonic echo and a datum is compared to export one second comparison signal by a zero crossings comparer;
This first comparison signal and this second comparison signal are carried out an intersection operation to export a zero crossing (Zero-cross) digital signal; And
A ultrasonic flow is calculated according to this zero crossing digital signal.
12. ultrasonic flow measuring methods as claimed in claim 11, are characterised in that, also comprise:
This first comparison signal and a reset signal are carried out a reciprocal cross set operation to produce a latch-up signal, this latch-up signal controls the latch mode of this pre-trigger comparer.
13. ultrasonic flow measuring methods as claimed in claim 11, it is characterized in that, this multistage trigger pip comprises multiple pre-trigger level, those pre-trigger level sequentially produce, and those pre-trigger level sequentially increase progressively, this zero crossing digital signal comprises an adjacent pre-trigger word pulse and a zero crossing digit pulse, and this pre-trigger word pulse produces at first, and this zero crossing digit pulse is closest to this pre-trigger word pulse.
14. ultrasonic flow measuring methods as claimed in claim 13, it is characterized in that, this calculation procedure comprises:
A flight time is calculated according to this zero crossing digit pulse; And
This ultrasonic flow is calculated according to the flight time difference that two groups of ultrasonic probes replace.
15. ultrasonic flow measuring methods as claimed in claim 13, is characterized in that, also comprise:
A peak swing of this ultrasonic echo is calculated according to this pre-trigger word pulse.
16. ultrasonic flow measuring methods as claimed in claim 15, is characterized in that, also comprise:
Using the feedback signal of this peak swing as a variable gain amplifier.
17. ultrasonic flow measuring methods as claimed in claim 15, is characterized in that, also comprise:
Calculate the overtime time, those pre-trigger level comprise one first adjacent pre-trigger level and one second pre-trigger level, and this second pre-trigger level is greater than this first pre-trigger level;
Wherein, when this multistage trigger pip equals this first pre-trigger level, within this overtime time, this pre-trigger word pulse is received;
Wherein, when this multistage trigger pip equals this second pre-trigger level, this pre-trigger word pulse cannot be received within this overtime time, select this first pre-trigger level as this peak swing.
18. ultrasonic flow measuring methods as claimed in claim 13, is characterized in that, also comprise:
Produce multiple zero crossing time array according to this zero crossing digital signal, those zero crossing time arrays correspond respectively to those pre-trigger level.
19. ultrasonic flow measuring methods as claimed in claim 18, it is characterized in that, those zero crossing time arrays are carried out a filtering operation by this calculation procedure, to produce a filtered data, then calculate this ultrasonic flow according to this filtered data.
20. ultrasonic flow measuring methods as claimed in claim 18, is characterized in that, this filtering operation is a median average filter computing.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW102121715 | 2013-06-19 | ||
| TW102121715A TWI500908B (en) | 2013-06-19 | 2013-06-19 | Ultrasonic flow meter and ultrasonic flow measuring |
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| CN104236646A true CN104236646A (en) | 2014-12-24 |
| CN104236646B CN104236646B (en) | 2017-07-14 |
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| TW (1) | TWI500908B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106323391A (en) * | 2015-06-30 | 2017-01-11 | 株式会社堀场Stec | Flow rate measuring device and flow rate controlling device |
| CN107131918A (en) * | 2017-07-02 | 2017-09-05 | 中国计量大学 | A kind of low-consumption ultrasonic flow measurement meter echo signal processing method and circuit |
| CN107478282A (en) * | 2017-08-17 | 2017-12-15 | 西南科技大学 | Ultrasonic flow rate detection signal processing method and processing device, time difference method ultrasonic testing system |
| CN110221202A (en) * | 2019-07-17 | 2019-09-10 | 西安西电开关电气有限公司 | A kind of current curve treating method and apparatus of the operating current of breaker |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI576126B (en) * | 2016-02-03 | 2017-04-01 | 金宙科技有限公司 | A device of liquid flow measurement |
| TWI692639B (en) * | 2019-10-03 | 2020-05-01 | 佳世達科技股份有限公司 | Ultrasonic probe |
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- 2013-06-19 TW TW102121715A patent/TWI500908B/en active
- 2013-07-22 CN CN201310308284.6A patent/CN104236646B/en active Active
Patent Citations (4)
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| JPH10332452A (en) * | 1997-05-28 | 1998-12-18 | Aichi Tokei Denki Co Ltd | Ultrasonic flowmeter |
| JP2002365109A (en) * | 2001-06-11 | 2002-12-18 | Aichi Tokei Denki Co Ltd | Ultrasonic flowmeter |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106323391A (en) * | 2015-06-30 | 2017-01-11 | 株式会社堀场Stec | Flow rate measuring device and flow rate controlling device |
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| CN107131918A (en) * | 2017-07-02 | 2017-09-05 | 中国计量大学 | A kind of low-consumption ultrasonic flow measurement meter echo signal processing method and circuit |
| CN107131918B (en) * | 2017-07-02 | 2023-09-12 | 中国计量大学 | Echo signal processing method and circuit of low-power-consumption ultrasonic flowmeter |
| CN107478282A (en) * | 2017-08-17 | 2017-12-15 | 西南科技大学 | Ultrasonic flow rate detection signal processing method and processing device, time difference method ultrasonic testing system |
| CN110221202A (en) * | 2019-07-17 | 2019-09-10 | 西安西电开关电气有限公司 | A kind of current curve treating method and apparatus of the operating current of breaker |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104236646B (en) | 2017-07-14 |
| TWI500908B (en) | 2015-09-21 |
| TW201500722A (en) | 2015-01-01 |
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