CN201909669U - Frequency measurement system of unicoil vibrating wire instrument - Google Patents
Frequency measurement system of unicoil vibrating wire instrument Download PDFInfo
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- CN201909669U CN201909669U CN2010206846459U CN201020684645U CN201909669U CN 201909669 U CN201909669 U CN 201909669U CN 2010206846459 U CN2010206846459 U CN 2010206846459U CN 201020684645 U CN201020684645 U CN 201020684645U CN 201909669 U CN201909669 U CN 201909669U
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Abstract
The utility model relates to a frequency measurement system of a unicoil vibrating wire instrument. The system comprises an excitation device, a switching circuit and a vibration pickup device, wherein the vibration pickup device comprises an AD converter, a digital signal processor and a master frequency extraction device sequentially connected; and the switching circuit leads the excitation device and the AD converter to connect with the frequency measuring coil in a unicoil vibrating wire instrument in different time periods. The system has the advantages that the anti-interference ability is enhanced and both the accuracy and the reliability of the frequency measurement of the unicoil vibrating wire instrument are improved.
Description
Technical field
The utility model relates to the frequency measuring system of the unicoil type vibration wire instrument in the safety monitoring instrument of health monitoring technical field, particularly a kind of Geotechnical Engineering of Geotechnical Engineering.
Background technology
In safety monitoring, adopt the physical quantitys such as ess-strain, temperature, seam aperture, seepage and distortion of safety monitoring instrument monitoring Geotechnical Engineerings such as type vibration wire (or claiming steel chord type) instrument usually, in order to the safety of analysis and judgement Geotechnical Engineering to Geotechnical Engineering.
Type vibration wire instrument (or claim vibrating string type sensor) by two ends fix, the string wire of homogeneous forms.String wire length is L, and in perception external influence power F (can be ess-strain, temperature, seam aperture, seepage and the distortion etc. of Geotechnical Engineering), string wire can produce the stretcher strain of Δ L, in elastic range, considers the influence of temperature T simultaneously,
Δ T=T-T wherein
0, α is a linear expansion coefficient, T
0, α, K be known constant number.The mechanical vibration natural frequency f of string wire can obtain by following formula:
Wherein E is the elastic modulus of string wire, ρ
vBe the density of string wire, λ is the Poisson's coefficient of string wire material, and these are permanent number.Above-mentioned two formula are put in order, eliminated
This common variable, drawing F is definite function of f and T, just can realize the measurement of F by measurement f and T.Wherein, frequency parameter f is the most key measurement factor.
At present in the type vibration wire instrument that use in the safety monitoring field, have various ways such as twin coil type vibration wire instrument, unicoil type vibration wire instrument, differential winding type vibration wire instrument according to the loop construction type, wherein unicoil type vibration wire instrument all has comparative advantage in many-sides such as kind, range of application, quantity.Fig. 1 is a unicoil type vibration wire apparatus structure synoptic diagram, string wire 1 is arranged in the magnetic field of frequency measurement coil 2 and permanent magnet 3 formations, by apply the exciting current signal of alternation to frequency measurement coil 2 two ends in the unicoil type vibration wire instrument, under the effect of permanent magnet 3, form alternating electromagnetic force, drive string wire 1 mechanical vibration take place, the string wire 1 of vibration is made cutting magnetic line movement in magnetic field, induce electromotive force in frequency measurement coil 2, and the frequency of induced potential is the vibration frequency of string wire 1.Traditional frequency measurement method adopts the frequency counting method, promptly adopt counter by measuring the induced potential recurrence interval, can record the vibration frequency of string wire 1, this method principle simple, intuitive is feasible, but the problem that in practice, has poor anti jamming capability, can count the form of undesired signal in the measurement result inevitably, cause the decline of measuring accuracy and reliability with step-by-step counting.And the safety monitoring of Geotechnical Engineering has very strict requirement to the reliability of safety monitoring instrument and the accuracy of measurement data, this just requires to make every effort to advanced, makes every effort to accurately and reliably on measuring principle and measuring method, so unicoil type vibration wire instrument adopts the said frequencies measuring method can not satisfy Testing requirement.
The utility model content
The poor anti jamming capability that the utility model adopts the frequency counting method to exist at the frequency measurement of existing unicoil type vibration wire instrument, the problem that causes measuring accuracy and reliability decrease, a kind of frequency measuring system of novel unicoil type vibration wire instrument is provided, this system more meets the principle of work of unicoil type vibration wire instrument on the measuring principle, increase antijamming capability, improved the accuracy and the reliability of unicoil type vibration wire instrument frequency measurement.
The technical solution of the utility model is as follows:
A kind of frequency measuring system of unicoil type vibration wire instrument, it is characterized in that, comprise exciting device, on-off circuit and pick-up device, described pick-up device comprises successively AD converter, digital signal processor and the dominant frequency extraction element that connects, and described on-off circuit links to each other exciting device and AD converter respectively at times with frequency measurement coil in the unicoil type vibration wire instrument; Describedly be meant at times: on-off circuit is communicated with exciting device and frequency measurement coil earlier, and exciting device applies the frequency sweep accumulation signal of alternation at frequency measurement coil two ends, form alternating electromagnetic force under the effect of permanent magnet, drives string wire generation mechanical vibration; On-off circuit cuts off being connected between exciting device and the frequency measurement coil again, and the mechanical vibration of string wire form the standing wave of single-frequency, and frequency measurement coil two ends form the induced potential signal consistent with string wire mechanical vibration frequency; On-off circuit is communicated with frequency measurement coil and AD converter again, described AD converter frequency acquisition is measured the induced potential signal that the coil two ends form, and transfer to digital signal processor and carry out the FFT spectrum analysis, described dominant frequency extraction element extracts dominant frequency signal in the frequency spectrum according to the maximum value method, obtains frequency measurement.
Described pick-up device also comprises amplification and rectification circuit, described amplification and rectification circuit is arranged between on-off circuit and the AD converter, imports AD converter again after the induced potential signal amplification shaping of described amplification and rectification circuit with the formation of frequency measurement coil two ends and carries out data acquisition.
Described exciting device comprises signal generator, and the two ends of described frequency measurement coil are connected to the output terminal of signal generator, and the frequency sweep accumulation signal that described signal generator produces alternation is applied to frequency measurement coil two ends.
Described AD converter is high precision, high-speed A/D converter.
Technique effect of the present utility model is as follows:
The frequency measuring system of the unicoil type vibration wire instrument that the utility model relates to, comprise exciting device, on-off circuit and pick-up device, the pick-up device comprises AD converter, DSP (Digital Signal Processor, digital signal processor) and the dominant frequency extraction element, carrying out circuit by on-off circuit selects, at times exciting device is linked to each other with frequency measurement coil in the unicoil type vibration wire instrument, or the frequency measurement coil is linked to each other with AD converter; Be that on-off circuit is communicated with exciting device and frequency measurement coil earlier, exciting device applies the frequency sweep accumulation signal of alternation at frequency measurement coil two ends, drive string wire generation mechanical vibration; On-off circuit cuts off and to be connected the frequency measurement coil two ends formation induced potential signal consistent with string wire mechanical vibration frequency between exciting device and the frequency measurement coil; On-off circuit is communicated with frequency measurement coil and AD converter again, the AD converter frequency acquisition is measured the induced potential signal that the coil two ends form, the induced potential signal is converted into digital signal, and transfer to DSP and carry out FFT (Fast Fourier Transform, fast fourier transform) spectrum analysis, finally extract dominant frequency signal in the frequency spectrum according to the maximum value method, obtain frequency measurement by the dominant frequency extraction element.Exciting device carries out exciting, AD converter, DSP and dominant frequency extraction element carry out pick-up, on-off circuit carries out the switching between exciting and the pick-up, the pick-up device has been realized the complete frequency spectrum analysis of frequency measurement coil induced potential signal, obtain this induced potential signal Spectrum Analysis result, the dominant frequency extraction element has adopted the criterion of maximum value method as the dominant frequency signal extraction in the frequency spectrum, has reduced the possibility of erroneous judgement.Because DSP is converted into frequency-region signal with the induced potential signal from time domain, because the randomness of undesired signal has determined it can not become maximum point in frequency spectrum, so can reliably realize the rejecting of undesired signal by the maximum value method.Avoid the frequency measurement of existing unicoil type vibration wire instrument to adopt the frequency counting method form of undesired signal with step-by-step counting can be counted in the measurement result, caused the problem of the decline of measuring accuracy and reliability.The dominant frequency signal that this system of the present utility model obtains is as the final frequency measurement result, accurately, realize the parameter measurement of unicoil type vibration wire instrument frequency reliably, the principle of work that more meets unicoil type vibration wire instrument on the measuring principle, increased antijamming capability, improved the accuracy and the reliability of the frequency measurement of unicoil type vibration wire instrument, the safety monitoring that can satisfy Geotechnical Engineering is to the strict demand of the accuracy of the reliability of safety monitoring instrument and measurement data.
Description of drawings
Fig. 1 is a unicoil type vibration wire apparatus structure synoptic diagram.
Fig. 2 is the preferred structure synoptic diagram of the frequency measuring system of the utility model unicoil type vibration wire instrument.
Fig. 3 is for applying the frequency sweep accumulation signal oscillogram of alternation at frequency measurement coil two ends.
Fig. 4 cancels the induced potential signal waveforms that frequency measurement coil two ends form behind the frequency sweep accumulation signal.
Fig. 5 is the process flow diagram of FFT spectrum analysis.
The spectrogram of Fig. 6 for obtaining after the FFT spectrum analysis.
Each label lists as follows among the figure:
The 1-string wire; 2-frequency measurement coil; The 3-permanent magnet; The 4-exciting device; 5-pick-up device; M-maximum value.
Embodiment
Below in conjunction with accompanying drawing the utility model is described.
The utility model relates to a kind of frequency measuring system of unicoil type vibration wire instrument, and its preferred structure synoptic diagram as shown in Figure 2.This system comprises exciting device 4, on-off circuit and pick-up device 5, wherein, exciting device 4 comprises signal generator, pick-up device 5 comprises successively amplification and rectification circuit, high precision, high-speed A/D converter, digital signal processor and the dominant frequency extraction element that connects, and on-off circuit links to each other signal generator and amplification and rectification circuit respectively at times with frequency measurement coil in the unicoil type vibration wire instrument.Be specially the line select switch circuit of on-off circuit as exciting and pick-up at times, when on-off circuit communications signals generator and frequency measurement coil, the A of frequency measurement coil 2, B two ends are connected to the output terminal of signal generator; After getting in touch between on-off circuit shutoff signal generator and the frequency measurement coil, can be communicated with frequency measurement coil and amplification and rectification circuit, be about to the A of frequency measurement coil, the input end that the B two ends are connected to amplification and rectification circuit.
This frequency measuring system to finish measuring process as follows: the output terminal that the A of frequency measurement coil 2, B two ends is connected to signal generator by on-off circuit, promptly be communicated with exciting device and prepare exciting, signal generator produces the frequency sweep accumulation signal of alternation as shown in Figure 3, affacts on the frequency measurement coil 2; Frequency measurement coil 2 under the effect of permanent magnet 3, produces the electromagnetic force of alternation owing to applied the frequency sweep accumulation signal of alternation thereby had exchange current to flow through, and drives string wire 1 mechanical vibration take place.After string wire produces mechanical vibration, by getting in touch between on-off circuit shutoff signal generator and the frequency measurement coil 2 (promptly cancelling the frequency sweep accumulation signal), simultaneously the frequency measurement coil is connected to the input end of amplification and rectification circuit, promptly is communicated with the pick-up device and prepares pick-up.Suitably wait for a period of time, allow the mechanical vibration of string wire 1 form the standing wave of single-frequency, because string wire 1 mechanical vibration, alternation cutting magnetic line, form the induced potential signal consistent (induced potential signal waveform as shown in Figure 4, its waveform is the damped oscillation waveform) with string wire 1 mechanical vibration frequency at frequency measurement coil 2 two ends.This induced potential signal amplifies shaping through amplification and rectification circuit, and amplification and rectification circuit is amplified to 2～3V with this induced potential signal from 5mV; By high precision, high-speed A/D converter the induced potential signal that amplifies after the shaping is carried out data acquisition, can gather induced potential signal more than 8000 as gathering sample, and export one group of data acquisition sample array.Data acquisition sample array forms the input sampling data sequence under the control of DSP, DSP carries out the FFT spectrum analysis according to flow process shown in Figure 5, being about to the input sampling data sequence arranges and input sampling data according to the coding backward, adopt butterfly computation to realize fast fourier transform again, analytical calculation picked up signal spectral data sequence by fast fourier transform, thereby obtain this signal Spectrum Analysis result, can obtain spectrogram shown in Figure 6 according to spectral data sequence, realize the complete frequency spectrum analysis of frequency measurement coil induced potential signal.From spectrogram, extract amplitude maximum point M by the dominant frequency extraction element according to the maximum value method then, point M frequency value corresponding f is exactly the dominant frequency signal in the frequency spectrum, because the frequency of the induced potential signal that frequency measurement coil 2 two ends form is consistent with string wire 1 mechanical vibration frequency, so a M frequency value corresponding f is this frequency measurement that measures just, to put M frequency value corresponding f as the final frequency measurement result, realize the measurement of unicoil type vibration wire instrument frequency parameter.
(exciting device and pick-up device are worked successively in this measuring system) carried out in frequency measuring system exciting and the pick-up timesharing that the utility model relates to, can be accurate, obtain the induced potential signal frequency value that produces on the frequency measurement coil reliably, because the frequency of the induced potential signal that frequency measurement coil two ends form is consistent with string wire mechanical vibration frequency, so obtain final measurement in the mode of picking up the frequency spectrum dominant frequency, realized the measurement of the frequency parameter of unicoil type vibration wire instrument, and the principle of work that more meets unicoil type vibration wire instrument on the measuring principle, it is more accurate to obtain than traditional frequency counting mode, more stable measurement result, its measuring accuracy can reach 0.1Hz, resolving power reaches 0.01Hz, the more important thing is the antijamming capability that has improved signal measurement.
Should be pointed out that the above embodiment can make those skilled in the art more fully understand the invention, but do not limit the present invention in any way creation.Therefore; although this instructions has been described in detail the invention with reference to drawings and Examples; but; those skilled in the art are to be understood that; still can make amendment or be equal to replacement the invention; in a word, all do not break away from the technical scheme and the improvement thereof of the spirit and scope of the invention, and it all should be encompassed in the middle of the protection domain of the invention patent.
Claims (4)
1. the frequency measuring system of a unicoil type vibration wire instrument, it is characterized in that, comprise exciting device, on-off circuit and pick-up device, described pick-up device comprises successively AD converter, digital signal processor and the dominant frequency extraction element that connects, and described on-off circuit links to each other exciting device and AD converter respectively at times with frequency measurement coil in the unicoil type vibration wire instrument; Describedly be meant at times: on-off circuit is communicated with exciting device and frequency measurement coil earlier, and exciting device applies the frequency sweep accumulation signal of alternation at frequency measurement coil two ends, form alternating electromagnetic force under the effect of permanent magnet, drives string wire generation mechanical vibration; On-off circuit cuts off being connected between exciting device and the frequency measurement coil again, and the mechanical vibration of string wire form the standing wave of single-frequency, and frequency measurement coil two ends form the induced potential signal consistent with string wire mechanical vibration frequency; On-off circuit is communicated with frequency measurement coil and AD converter again, described AD converter frequency acquisition is measured the induced potential signal that the coil two ends form, and transfer to digital signal processor and carry out the FFT spectrum analysis, described dominant frequency extraction element extracts dominant frequency signal in the frequency spectrum according to the maximum value method, obtains frequency measurement.
2. frequency measuring system according to claim 1, it is characterized in that, described pick-up device also comprises amplification and rectification circuit, described amplification and rectification circuit is arranged between on-off circuit and the AD converter, imports AD converter again after the induced potential signal amplification shaping of described amplification and rectification circuit with the formation of frequency measurement coil two ends and carries out data acquisition.
3. frequency measuring system according to claim 1 and 2, it is characterized in that, described exciting device comprises signal generator, the two ends of described frequency measurement coil are connected to the output terminal of signal generator, and the frequency sweep accumulation signal that described signal generator produces alternation is applied to frequency measurement coil two ends.
4. frequency measuring system according to claim 3 is characterized in that, described AD converter is high precision, high-speed A/D converter.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2010206846459U CN201909669U (en) | 2010-12-28 | 2010-12-28 | Frequency measurement system of unicoil vibrating wire instrument |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2010206846459U CN201909669U (en) | 2010-12-28 | 2010-12-28 | Frequency measurement system of unicoil vibrating wire instrument |
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| CN201909669U true CN201909669U (en) | 2011-07-27 |
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| CN2010206846459U Expired - Lifetime CN201909669U (en) | 2010-12-28 | 2010-12-28 | Frequency measurement system of unicoil vibrating wire instrument |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102141428A (en) * | 2010-12-28 | 2011-08-03 | 基康仪器(北京)有限公司 | Method and system for measuring frequency of single coil vibrating instrument |
| CN102426052A (en) * | 2011-09-16 | 2012-04-25 | 重庆恩菲斯软件有限公司 | Vibration wire type data acquisition system and method |
| CN104180839A (en) * | 2014-07-15 | 2014-12-03 | 常州大学 | Rapid measurement method for vibrating-wire sensor and detection circuit |
| CN106225960A (en) * | 2016-08-31 | 2016-12-14 | 成都众邦凯测科技有限公司 | A kind of single coil vibrating sensor exciting device and excitation method |
| CN114323356A (en) * | 2022-01-06 | 2022-04-12 | 大连乐图数字科技有限公司 | Vibrating wire type sensor measuring instrument and measuring method thereof |
-
2010
- 2010-12-28 CN CN2010206846459U patent/CN201909669U/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102141428A (en) * | 2010-12-28 | 2011-08-03 | 基康仪器(北京)有限公司 | Method and system for measuring frequency of single coil vibrating instrument |
| CN102426052A (en) * | 2011-09-16 | 2012-04-25 | 重庆恩菲斯软件有限公司 | Vibration wire type data acquisition system and method |
| CN104180839A (en) * | 2014-07-15 | 2014-12-03 | 常州大学 | Rapid measurement method for vibrating-wire sensor and detection circuit |
| CN106225960A (en) * | 2016-08-31 | 2016-12-14 | 成都众邦凯测科技有限公司 | A kind of single coil vibrating sensor exciting device and excitation method |
| CN106225960B (en) * | 2016-08-31 | 2019-05-28 | 成都众邦凯测科技有限公司 | A kind of single coil vibrating sensor exciting device and excitation method |
| CN114323356A (en) * | 2022-01-06 | 2022-04-12 | 大连乐图数字科技有限公司 | Vibrating wire type sensor measuring instrument and measuring method thereof |
| CN114323356B (en) * | 2022-01-06 | 2024-06-11 | 大连乐图数字科技有限公司 | Vibrating wire type sensor measuring instrument and measuring method thereof |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: JIKANG INSTRUMENT CO., LTD. Free format text: FORMER NAME: JIKANG INSTRUMENT(BEIJING) CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: 102401, 3, Binhe West Street, Triumph Street, Beijing, Fangshan District, Liangxiang Patentee after: CHINA GEOKON INSTRUMENTS CO., LTD. Address before: 102401, 3, Binhe West Street, Triumph Street, Beijing, Fangshan District, Liangxiang Patentee before: Jikang Instrument(Beijing) Co., Ltd. |
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| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110727 |