CN101339200B - Acoustic flow measurement method and apparatus - Google Patents

Abstract

The invention discloses an acoustic flow measurement device and a method thereof. The acoustic flow measurement device is adopted between observation stations for sending sound waves to the opposite side simultaneously, then receiving sound waves transmitted by the opposite side, the bidirectional propagation time of the sound waves between the two observation stations is obtained by calculating; the difference and the sum of the acoustic signals bidirectional propagation time are used for reversing the mean velocity and the average temperature between observation stations. The invention can carry on the vertical sample based on sound propagation multi-path effect by only using a pair of sound-source-receiver; as the ocean interior images can be obtained by observing the external measurement of the sea; compared with the traditional method, the synchronous measurement with the large-scale and long time between two points by using a pair of instruments can be realized; the collection performance of the sound propagation can obtain ocean environment parameters with the vast scale in space and the average time which can not be obtained by the traditional point sensor; the method solves the problem that the observing is affected by shipping and fisheries activity.

Description

A kind of acoustic flow measurement method and device

[technical field]

The present invention relates to ocean monitoring technologytechnologies field and Large River field of measuring technique, be specifically related to a kind of acoustic flow measurement method and device.

[technical background]

To the measurement in flow field, ocean and Large River flow velocity and temperature field, generally use current meter (using Yu Haiyang) or velocimeter at present.General one of these current meters or velocimeter can only be measured a bit or the flow velocity of a section.Such as has the only flow velocity of a point of energy measurement of long historical An Dela current meter.And the general about 500m of energy measurement of the acoustic Doppler fluid velocity profile instrument (Acoustic Doppler Current Profiler) that grows up from the eighties is with interior fluid velocity profile.Obtain extra large surperficial environmental element data though seasat remote sensing observations and ground wave radar observation technology can continue large tracts of land, can't obtain the information of ocean or inside, river.

As carrying out simultaneous observation, need a plurality of current meters (as ADCP etc.) to walk boat observation for a long time or a large amount of anchor system observation realizes to a certain big marine site.Be subjected to the restriction in instrument and equipment and geographic position etc., arrive synchronous observational data scarcely ever.Such as wanting long-time continuous ground to measure flow or the thermoflux of passing through straits or river course, conventional method is to realize by walking aerial survey stream or laying a lot of current meters.And these conventional methods are subjected to the restriction of busy shipping in these areas and the fishery activity that enlivens.

Therefore, present flow measurement device all can not finely satisfy the observation requirement that offshore is comprised the extensive long-time continuous of marine environment in river, and observation process is subjected to the restriction of shipping and fishery activity.

[summary of the invention]

Purpose of the present invention is exactly in order to solve problems of the prior art, a kind of acoustic flow measurement method and device are proposed, can satisfy observation requirement, and solve the problem that influenced by shipping and fishery activity in the observation the extensive long-time continuous of marine environment of offshore.

For achieving the above object, patent of the present invention has proposed a kind of acoustic flow measurement device, comprises

Battery unit: the power supply that is total system;

Clock unit:, provide the time signal of standard for total system by the time signal of gps antenna reception gps satellite;

Signal takes place and processing unit: comprise that signal produces radiating portion and signal Return Reception Dept. branch, described signal produces the carrier signal that radiating portion produces certain frequency, incoming modem carries out coded modulation, modulation back signal power input amplifier carries out energy and amplifies, be loaded into transducer through impedance matching again, transducer emission sound wave; After described Return Reception Dept. branch converts the acoustic signals that receives to electric signal by transducer, amplify in advance, send into modulator-demodular unit after the Filtering Processing and carry out demodulation, signal carries out matched filter processing again after the demodulation, obtains the acoustic propagation time at last and records in the memory storage;

Transducer unit: comprise transmitting transducer and the receiving transducer of realizing that electric signal and acoustical signal are changed mutually;

Outer computer: take place to be connected with signal, carry out parameter setting and data acquisition with processing unit.

As preferably, the centre frequency of described transducer unit is 5kHz, and bandwidth is 3-7kHz, horizontal direction 360 degree non-directives.

For achieving the above object, patent of the present invention has also proposed a kind of acoustic flow measurement method, adopt the acoustic flow measurement device between two research stations, to send sound wave to the other side simultaneously, receive the sound wave that the other side sends then respectively, the twocouese travel-time of sound wave at two research station interdigits tried to achieve in calculating, and mean flow rate and the medial temperature of using acoustical signal twocouese propagation time difference to reach and come inverting research station interdigit.

The beneficial effect of patent of the present invention: the present invention is based on the many ways of acoustic propagation effect, only just can carry out vertical sampling to the ocean with a pair of sound source-receiver; Just can obtain the ocean interior image by peripheral measurement the in observation marine site; Compare with classic method, available a pair of instrument just can carry out long-time synchro measure on a large scale to point-to-point transmission; The characteristic of accumulation of acoustic propagation can obtain the space large scale, the time averaging marine environment estimation that the traditional point sensor measurement of dependence is difficult to obtain.Solved the problem that influenced by shipping and fishery activity etc. in the observation.

Describe the present invention below in conjunction with the drawings and specific embodiments, but not as a limitation of the invention.

[description of drawings]

Fig. 1 is the schematic block circuit diagram of acoustic flow measurement device of the present invention;

Fig. 2 is the structural representation stereographic map in electronics storehouse in the acoustic flow measurement device of the present invention;

Fig. 3 is the structural representation cut-open view in electronics storehouse in the acoustic flow measurement device of the present invention;

Fig. 4 is the structural representation vertical view in electronics storehouse in the acoustic flow measurement device of the present invention;

Fig. 5 is the structural representation of battery unit;

Fig. 6 is the two-way acoustic propagation observation schematic diagram of mechanism of acoustic flow measurement method of the present invention;

Fig. 7 is the workflow diagram of acoustic flow measurement method of the present invention;

Fig. 8 a is the bank base observation synoptic diagram of acoustic flow measurement device of the present invention;

Fig. 8 b is the anchorage observation synoptic diagram of acoustic flow measurement device of the present invention;

Fig. 8 c is the section observation synoptic diagram of acoustic flow measurement device of the present invention;

Fig. 8 d is the stream measurement synoptic diagram of acoustic flow measurement device of the present invention;

Fig. 8 e is the straits observation synoptic diagram of acoustic flow measurement device of the present invention.

[embodiment]

Consult Fig. 1,2,3,4,5, the acoustic flow measurement device comprises

Battery unit: the power supply that is total system; But adopt ordinary city dealer's recharge type battery truck battery.

Clock unit 18:, provide the time signal of standard for total system by the time signal of gps antenna reception gps satellite;

Signal takes place and processing unit: comprise that signal produces radiating portion and signal Return Reception Dept. branch, described signal produces the carrier signal that radiating portion produces certain frequency, incoming modem carries out coded modulation, modulation back signal power input amplifier carries out energy and amplifies, be loaded into transducer through impedance matching again, transducer emission sound wave; After described Return Reception Dept. branch converts the acoustic signals that receives to electric signal by transducer, amplify in advance, send into modulator-demodular unit after the Filtering Processing and carry out demodulation, signal carries out matched filter processing again after the demodulation, obtains the acoustic propagation time at last and records in the memory storage.

Transducer unit 15: comprise transmitting transducer and the receiving transducer of realizing that electric signal and acoustical signal are changed mutually; The centre frequency of described transducer unit is 5kHz, and bandwidth is 3-7kHz, horizontal direction 360 degree non-directives.

Outer computer 13: take place to be connected with signal, carry out parameter setting and data acquisition with processing unit.

Consult Fig. 1, the signal acquiring system circuit block diagram, transducer 15 and internal circuit board 10 by the gps antenna 11 of outside, outer computer 13, transceiver constitute, and wherein internal circuit board 10 is made up of GPS receiving element 19, clock unit 18, modulus/D/A conversion unit 17, power amplifier unit 14, receiving element 16, digital signal processing unit 12 and flash cell.The GPS15 receiver that GPS receiving element 19 adopts GARMIN company to produce, clock unit 18 is made of 16 bus single-chip microcomputers (MSP430F149) and the peripheral components thereof of the band Flash of Texas Instruments exploitation, and modulus/D/A conversion unit 17 is that the sampling rate by Texas Instruments's exploitation is 16 the two-way analog to digital converters (ADS8361) of 500ksps and the CPLD device (EPM7128) (processing transmits and receives) and the peripheral components formation thereof of Alter company exploitation.Digital signal processing unit 12 is made of the digital signal processor spare (TMS320VC5509) and the peripheral component thereof of Texas Instruments's exploitation.Homemade broadband overflow-type annulus transducer (LiuJiwu-A type) during the transducer 15 of outside transceiver adopts, outer computer 13 can be selected notebook computer for use.

Consult Fig. 2,3,4, the major part of acoustic flow measurement device is the electronics storehouse, and the electronics storehouse comprises that clock unit, signal take place and processing unit.Contour structures is: comprise that diameter is 170mm, long be the circular stack shell 24 of 845mm, in wiring board mounting bracket 32,33 is arranged, gps antenna installation position 31 has power interface, transducer interface, communication interface totally 3 interfaces and a spare interface 23 outward.Be loam cake 22 above the stack shell 24, the bottom is a storehouse base 25.Consult Fig. 5, the battery case outside drawing of battery unit is installed, comprise that diameter is 300mm, length is the circular batteries stack shell 54 of 425mm, and loam cake 51 is arranged at the top of battery stack shell 54, and the bottom is a base 56, battery plate 52 is arranged in the battery tube, battery 53 and pearl foam-rubber cushion 55 are installed.

Apparatus of the present invention can be selected M sequential coding modulation for use, and emission sonic interval 1 minute to 24 hours is optional, and the output acoustic wave energy is 2kW, and measuring distance is 0.5-30km.Shown in Fig. 8 a, 8b, 8c, 8d, 8e, several erect-positions when having provided apparatus of the present invention actual observation are to arrangement plan.Fig. 8 a is the bank configuration, outer computer 13, and battery case 82 and electronics storehouse 83 are placed on the bank, and tie cable 84 is fixing by steel part 85 guiding mutually with underwater transducer 86 by cable 84, and electronics storehouse 83 is provided with gps antenna 81.Fig. 8 b is the anchorage configuration, and electronics storehouse 83 is placed on the sea by surperficial ball float 87, connects underwater transducer 86 by cable, and underwater transducer 86 upwards connects ball float 88 under water, connects pouring weight 89 downwards.

Consult Fig. 7, at first systems inspection and setting up procedure, promptly outer computer carries out status checking and running parameter setting to system, judges that normally whether system works, system starts working according to setting then, the first step is obtained gps signal, and whether decision sends acoustical signal and prepare to receive acoustical signal, and second step was carried out relevant treatment to received signal, tracer signal arrives information, judge whether observation finishes,, continue transmission signal and received signal and observe as finishing.

The using method of acoustic flow measurement device of the present invention comprises the steps:

(1) before observation, with computing machine main observed parameter is set, at the two ends of observation section apparatus of the present invention (containing acoustical signal transmits and receives) are set respectively;

(2) when observation, two observation erect-positions are launched sound wave to the other side simultaneously automatically, and simultaneously, the sound wave receiving trap receives and the record acoustic signals;

(3) take out observation data from apparatus of the present invention, carry out data processing, obtain the mean flow rate and the temperature field of observation section gathering sound wave signal time of arrival.

In the described step (1), can adopt bank base fixed sound to transmit and receive device in the coastal waters, utilize gps signal to carry out the website location.Also can adopt surperficial buoy form that apparatus of the present invention are arranged in the water.

In the described step (2), the acoustic signals after the emission phase-shift keying (PSK) modulation utilizes the time reference signal of GPS to carry out the time synchronized of sound wave emissions, receives and adopts matched filtering technique.

In the described step (3), data processing refers to adopt self-editing program that the acoustical signal of gathering is analyzed and handled.

Consult Fig. 6, adopt the acoustic flow measurement device between two research stations, to send sound wave to the other side simultaneously, receive the sound wave that the other side sends then respectively, the twocouese travel-time of sound wave at two research station interdigits tried to achieve in calculating, and mean flow rate and the medial temperature of using acoustical signal twocouese propagation time difference to reach and come inverting research station interdigit.

Ignore the bending of acoustical signal horizontal direction, ping is along sound ray path Γ _iTravel-time T _iFor:

$T_i={\∫}_{{\mathrm{\Γ}}_i}\frac{\mathrm{ds}}{C\left(x\right)+u\·\mathrm{\τ}},---\left(1\right)$

Wherein, C (x), u are the three-dimensional velocity of sound and velocity field vector, and τ is sound ray unit's tangent vector, and s is the sound ray arc length.In the ocean, can define with reference to velocity of sound C ₀(x) to such an extent as to:

C(x)＝C ₀(x)+δc(x)，

Wherein, δ c (x)＜＜C (x), reference bi acoustic propagation synoptic diagram (seeing accompanying drawing 1) is with small parameter δ c (x)/C ₀(x) and u/C ₀(x) to T _iLaunching also, linearization can obtain:

$d_i=(T_i^{+}-T_i^{-})\≈-2{\∫}_{{\mathrm{\Γ}}_{0i}}\frac{u\·\mathrm{\π}}{C_0{\left(x\right)}^2}\mathrm{ds},---\left(2\right)$

$s_i=(T_i^{+}+T_i^{-})\≈-2{\∫}_{{\mathrm{\Γ}}_{0i}}\frac{\mathrm{\δc}\left(x\right)}{C_0{\left(x\right)}^2}\mathrm{ds}---\left(3\right)$

Here Γ _0iBe with reference to velocity of sound C ₀(x) the sound ray road under the condition.By relational expression (2) and (3) as can be known sound pulse be approximately along the flow velocity u τ of sound ray direction and the linear function of δ c (x) along the difference and the sum in sound ray travel-time.

Native system is used for measuring the ping travel-time of two research station interdigits, and you obtain with (3) with relational expression (2) and get flow velocity and temperature (velocity of sound) then.

The foregoing description is embodiments of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present invention and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.

Claims (2)

1. the acoustic flow measurement device is characterized in that: comprise

Battery unit: the power supply that is total system;

Clock unit: by the time signal of gps antenna reception gps satellite, the interior strange land erect-position wireless time of realizing provides the time signal of standard synchronously on a large scale for total system;

Signal takes place and processing unit: comprise that signal produces radiating portion and signal Return Reception Dept. branch, described signal produces the carrier signal that radiating portion at first produces certain frequency, incoming modem carries out coded modulation, modulation back signal power input amplifier carries out energy and amplifies, be loaded into transducer through impedance matching again, transducer emission sound wave; After described Return Reception Dept. branch converts the acoustic signals that receives to electric signal by transducer, amplify at first in advance, send into modulator-demodular unit after the Filtering Processing and carry out demodulation, signal carries out matched filter processing again after the demodulation, obtains the acoustic propagation time at last and records in the memory storage;

Transducer unit: comprise transmitting transducer and the receiving transducer of realizing that electric signal and acoustical signal are changed mutually;

Outer computer: take place to be connected with signal, carry out parameter setting and data acquisition with processing unit.

2. acoustic flow measurement device as claimed in claim 1 is characterized in that: for satisfying big range finding requirement, the centre frequency of described transducer unit is 5kHz, and bandwidth is 3-7kHz, horizontal direction 360 degree non-directives.

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