CN101644775B - Synchronous ranging system and synchronous ranging method - Google Patents
Synchronous ranging system and synchronous ranging method Download PDFInfo
- Publication number
- CN101644775B CN101644775B CN2008102263701A CN200810226370A CN101644775B CN 101644775 B CN101644775 B CN 101644775B CN 2008102263701 A CN2008102263701 A CN 2008102263701A CN 200810226370 A CN200810226370 A CN 200810226370A CN 101644775 B CN101644775 B CN 101644775B
- Authority
- CN
- China
- Prior art keywords
- digital
- analog
- signal
- converter
- signal processor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The invention discloses a synchronous ranging system and a synchronous ranging method. The system comprises a main control computer, a digital signal processor (DSP), a digital to analog converter (D/A card), a detection signal emitting and receiving device and an analog to digital converter (A/D card). In all ranging periods in the whole ranging process of the ranging system and the method, the D/A card and the A/D card are in a continuous working state, adopt the same clock signal for ranging timing and have conversion frequencies satisfying an integer multiple relationship. The invention has the advantages that (1) the non-real-time property of an operating system of a host is more tolerable; (2) the influence of inconsistent frequency drift of single crystal oscillators is eliminated, and buffer data on the cards are unnecessarily managed in each measuring period so that the influence of the non-ideal equipment characteristics on the ranging accuracy is less.
Description
Technical field
The present invention relates to utilize target echo signal that target is carried out the range finding field, particularly a kind of synchronous range measurement system of target echo signal and method utilized.
Background technology
In order to provide the estimated value of target range, the active sonar system needs the mistiming of accurate Calculation active signal x time and echoed signal due in.Traditional implementation method is: digital/analog converter DA and analog/digital converter AD are subjected to main frame (for example PC) control, in a detect cycle, when preparing emission active probe signal, then open the DA card and make it work, close the DA card again after the active probe signal battery has fired; Start the AD card then and begin image data, close the AD card after detect cycle is finished again; In each detect cycle, DA and AD calorie requirement enable repeatedly, forbid.
Under this working method, have several factors may bring artificial range error: at first, Windows commonly used on the PC is not a real time operating system, therefore, must be coarse during based on the survey of this system; Secondly, owing to need between different detect cycles, enable, forbid DA and AD card repeatedly, and the data queue that blocks in the buffer memory device is managed, this might bring the unstable of integrated circuit board hardware effort and introduce artificial range error; Moreover the input clock of DA in the sonar system and AD card is independent of each other often, and independently the drift of clock source frequency is different, to the signal of the such life period of similar linear FM signal-frequency couple characteristic, will bring range error.
Summary of the invention
In order to overcome the deficiency that there is certain time determination error in traditional distance-finding method, the invention provides a kind of synchronous range finding system and method, this system and method is in all the range finding cycles in whole ranging process, carry out data transmission between digital signal processor DSP and DA, the AD card continuously, DA and AD card also carry out data-switching incessantly under the driving in same clock source simultaneously, and calculate the time-delay that sonar receives the active echoed signal according to the frequency in this clock source.
Described synchronous range finding system comprises:
One main control computer is used for controlling and provide man-machine operation interface and interface to each integrated circuit board of system.
One digital signal processor (also can be two independently digital signal processors), be used for sending the active probe signal to the detectable signal transmitting and receiving device, receive sampled data, the processing target echoed signal of analog/digital converter simultaneously by digital/analog converter.
One digital/analog converter links to each other with digital signal processor by transmission data in real time port; Be used for the digital signal that digital signal processor sends is converted to simulating signal, and this simulating signal is sent to the detectable signal transmitting and receiving device.
One detectable signal transmitting and receiving device is used for the transmitting instructions active probe signal according to digital signal processor, and the receiving target echoed signal.And
One analog/digital converter links to each other with digital signal processor by transmission data in real time port; Be used to gather the target echo signal that the detectable signal transmitting and receiving device receives, this target echo signal be converted to digital signal, and this digital signal is sent to digital signal processor processes.
Wherein, in whole ranging process, described digital/analog converter and analog/digital converter are in the continuous firing state; When digital/analog converter and analog/digital converter adopt same clock signal to carry out range-viewfinder, but the divide ratio that uses can be different, and the inversion frequency of the two also can be different, i.e. the inversion frequency F of described digital/analog converter
S1Inversion frequency F with analog/digital converter
S2Satisfy integral multiple relation, that is: FS1=nFS2 or FS2=nFS1, wherein, n is the integral multiple divide ratio.
In each detect cycle, digital signal processor receives the sampled data of analog/digital converter continuously, if digital signal processor detects target echo signal from sampled data, then digital signal processor is handled sampled data, finishes the range finding location to target; If do not detect target echo signal, then directly abandon this sampled data.
Wherein, described transmission data in real time port can be Link, UART or USB port.
Wherein, described same clock signal is by following: (a) being sent to any mode that analog/digital converter, (b) be sent to digital/analog converter or (c) sent to digital/analog converter and analog/digital converter simultaneously by external clock reference by analog/digital converter by digital/analog converter provides.
Wherein, described detectable signal transmitting and receiving device is active sonar equipment or radar.
A kind of synchronous range finding method provided by the invention, concrete steps comprise:
(1) main control computer is to digital/analog converter with analog/digital converter enables and initialization operation; Digital/analog converter and analog/digital converter are driven by same clock signal, are ready; The inversion frequency F of digital/analog converter
S1Inversion frequency F with analog/digital converter
S2, satisfy integral multiple frequency division relation, that is: FS1=nFS2 or FS2=nFS1, wherein, n is the integral multiple divide ratio.
(2) digital signal processor sends complete ' 0 ' Frame by transmission data in real time port to digital/analog converter, and digital/analog converter carries out the digital-to-analog conversion; Simultaneously, analog/digital converter begins to carry out analog-digital conversion, and sampled data is sent to digital signal processor by transmission data in real time port; At whole ranging process, digital/analog converter and analog/digital converter are in the continuous firing state.
(3) enter a detect cycle after, digital signal processor stops to send complete ' 0 ' Frame, begins the active probe signal is sent to digital/analog converter; After transmission finishes, continue to send complete ' 0 ' Frame.
(4) digital/analog converter becomes simulating signal with the active probe conversion of signals, and sends simulating signal to the detectable signal transmitting and receiving device; The signal transmitting and receiving device is received instruction back emission active probe signal; Begin the receiving target echoed signal again after emission is finished, and send target echo signal to analog/digital converter, analog/digital converter converts the target echo signal that receives to digital signal, and sends this digital signal to digital signal processor.
(5) digital signal processor receives the sampled data of analog/digital converter continuously, if digital signal processor detects target echo signal from sampled data, then digital signal processor is handled this sampled data, finishes the range finding location to target; If do not detect target echo signal, then directly abandon this sampled data.
The invention has the advantages that:
1, system and method for the present invention is more tolerant to the non real-time of host operating system.
2, the DA in the system and method for the present invention, AD card adopt same clock signal, have eliminated the inconsistent influence of independent crystal oscillator frequency drift; Also needn't make distance accuracy be subjected to the influence of the undesirable property of device characteristics littler to data cached managing on the card in each measuring period.
Description of drawings
Fig. 1 is specific embodiment of the invention synchronous range finding system framework figure;
Fig. 2 is the timing relation figure of specific embodiment of the invention synchronous range finding method simulating signal and Link port data frame;
Fig. 3 is a specific embodiment of the invention synchronous range finding method flow diagram;
Fig. 4 is a specific embodiment of the invention synchronous range finding method Link port data transmission synoptic diagram.
Embodiment
With the active sonar range measurement system, specify system and method for the present invention below.The synchronous range finding system (as shown in Figure 1) of this specific embodiment adopts two DSP, respectively by Link port and DA card and AD card connection, DA card, AD card are connected with underwater transducer with signal conditioner by power amplifier PA respectively, in all range finding cycles in whole ranging process, DA card and AD card are in the continuous firing state; When DA card and AD card adopt same clock signal to carry out range-viewfinder.
Range measurement principle is as follows: establish homogeneous media, the constant c of being of the velocity of sound, emission length is NT
s(T
s=1/f
sBe the sampling period) active signal s (n), suppose that the sampling clock frequency of DA card and AD card is consistent, then receiving echoed signal can be expressed as:
r(n)＝As[n-τ(n)]+g(n) (1)
A is the amplitude fading factor in the formula, and it changes with distance R; τ (n) propagates the r (n) the bring time delay with respect to s (n) with what number of samples was represented by the sound wave round trip, when sonar and the detection of a target keep relative when static τ (n) be constant T, τ when radially relative motion is arranged between the two (n) n variation in time; G (n) is a noise.
Suppose that velocity of sound c is a fixed numbers, sonar is relative static with the detection of a target maintenance at a distance of the R place, no radial motion, and τ (n)=T, then the computing formula of distance is:
R＝cT/2 (2)
Based on above-mentioned principle, it is as follows to narrate this distance-finding method:
After sonar system powered up and brings into operation, PC at first sticked into enforcement energy and initialization operation to DA, AD; Then, the DSP0 that connects the DA card just sends complete ' 0 ' sequence by the Link port to the DA card, makes the DA card begin to carry out the digital-to-analog conversion; The AD card also begins to carry out analog-digital conversion, and sends sampled data to DSP1 by the Link port; Afterwards, AD and DA card just are in the continuous firing state, until system closing.
In each detect cycle, when needs emission active sonar detectable signal s (n), DSP0 ends to send complete ' 0 ' sequence to DA, sends signal s (n) and change into, recovers to send complete ' 0 ' sequence after being sent completely again; The DSP1 that connects the AD card then receives the sampled data that the AD card sends continuously, and when needs detected target echo from sampled data, DSP1 just handled sampled data, otherwise just directly abandons.
Frequency drift is inconsistent when using independent clock source in order to overcome DA and AD, uses in this distance-finding method that clockwise DA, AD card provide clock signal when same, and when utilizing this clock source to carry out accurate range-viewfinder.
Fig. 2 is the timing relation figure of simulating signal and Link port data frame.
Idiographic flow following (as shown in Figure 3):
1, sonar system powers up startup;
2, PC sticks into operations such as horizontal reset, initialization, frequency configuration to DA and AD.
3, DA and AD card are driven by same clock source (supposing that frequency is 75KHz), are ready.
4, PC is provided with the zone bit of DSP0, makes it begin to send complete ' 0 ' frame to the DA card; Simultaneously, the control word of AD card is set, makes it begin to carry out analog-digital conversion work.
5, the AD card begins to carry out analog-digital conversion work.At first sampled signal is placed in the FIFO buffer memory on the card, is assembled into Frame then, and sends to DSP1 by the Link port.Suppose that every frame data length is 4ms, be that 300 sampled points are arranged on the single passage, because the transmission speed of Link port is higher than the generation speed of AD sampled data, therefore, (such as 1ms) just can give DSP1 by the Link port transmission with this 4ms sampled data in the relatively short time.The Link port is waiting for that AD generates new sampled data, when accumulation reaches 300 sampled points, sends to DSP1 with regard to framing, as shown in Figure 2 all the time.
6, because detect cycle does not also begin, DSP1 thinks invalid data after receiving the Frame that the AD card sends, and does not carry out subsequent treatment, is that unit abandons with the frame.
7, DSP0 sends complete ' 0 ' frame by the Link port to the DA card.
8, ' 0 ' frame is entirely received in the DA clamping, through the displacement of FIFO buffer memory device, Serial No. is converted to simulating signal sends out.
9, enter a detect cycle after, DSP stops to send complete ' 0 ' frame to the DA card, changes into beginning active probe signal s (n) is sent to the DA card, this takies one or several Frame possibly, if s (n) can't fill up a certain frame, then mends ' 0 ' at its afterbody.Synchronizing signal control power amplifier is only just started working receiving s (t) (the simulation output of s (n) sequence) time, send the green end transducer to after will s (t) amplifying, and all the other times, power amplifier is in closed condition.Send s (n) afterwards, continue to send complete ' 0 ' frame again to the DA card.Because the transmission speed of Link port is higher than the speed that DA sticks into line number word-analog-converted, the Link port is all the time at the Frame of waiting for that the DA card please be looked for novelty, when DA card FIFO buffer cleaned out enough storage spaces, DSP0 just sent new Frame to the DA card, as shown in Figure 2.
10, power amplifier is carried the simulating signal of coming to amplify DA and is sent to underwater transducer afterwards.
11, transducer is launched electric signal with the form of sound wave, surveys target in the water.
12, DSP0 issues sequence s (n) after the DA card, writes control word again in the memory headroom of DSP1, and indication DSP1 begins to handle the AD sampled signal that this detect cycle receives.
13, DSP1 stops to abandon the AD sample data frames that receives, and the sampled data that will newly receive is sent into follow-up processing unit frame by frame and is handled, suppose that a detect cycle is 10s, then to handle about 10s/4ms=2500 frame data in each detect cycle, when counter reaches 2500 frames, think that promptly this cycle finishes.
14, after one-period was finished, DSP0 still continued to send complete ' 0 ' frame to the DA card; DSP1 still continues to receive and abandon the sample data frames that the AD card is sent, and DA, AD card then continue to carry out incessantly data-switching work.
If 15 main frames are issued an order, begin next detect cycle, then forward step 9 to; Otherwise forward step 14 to.
If 16 main frames are assigned shutdown command, then above-mentioned each module is all out of service, system closing.
Wherein, the length in each cycle is to rely on DA, AD card clock to come accurate timing, and total system is in the synchronous working state within the single cycle, as shown in Figure 4; Then sending data by PC notice DSP0 to the DA card during startup in each cycle and begin, is asynchronous between adjacent two cycles therefore, and its time interval may be 11s, 12s or 13s etc.But because of DA, AD card is to carry out data-switching continuously and carry out data interaction by the Link port under the control in same clock source, therefore, though the time interval between adjacent two cycles is not a fixed numbers, but should the time interval must be the integral multiple of Frame length, and the relative time difference Δ T of DA and AD Frame remain unchanged in the different cycles among Fig. 4.
The present invention has overcome the deficiency that there is certain time determination error in traditional distance-finding method in the active sonar system: the non real-time to host operating system is more tolerant; DA, AD card adopt same clock signal, have eliminated the inconsistent influence of independent crystal oscillator frequency drift; Also needn't be to data cached managing on the card in each measuring period.Making distance accuracy be subjected to the influence of the undesirable property of device characteristics littler, is a kind of sane distance-finding method.
The present invention also can have following variation example:
1, carry out between DSP and DA, the AD card data transmission port can but be not limited to the Link port, also can be other real-time ports that can transmit data, such as UART, USB etc.
2, clock signal can be given AD card by the DA card, also can give DA card by the AD card, perhaps flows to DA and AD card simultaneously by external clock reference.
3, DA and the shared same clock of AD card source, but the divide ratio that uses can be different, thereby the inversion frequency of the two also can be different.
4, control and what stick into that line data transmits by Link port and DA and AD both can be same dsp chip also can be two independently dsp chips.
5, green end transmitting transducer and receiving hydrophone both can be to receive and dispatch to close to install to be equipped with, and also can be bistatics.
6, the scope of application of this method is not limited only to active sonar equipment, also can be the launching simulation detectable signal and utilize to receive echo to the find range miscellaneous equipment of location of target, such as radar etc.
Native system and method be practical application in certain active sonar experimental facilities, excellent performance.When directly gathering when the sample frequency of AD card employing 75KHz and to the simulating signal of DA card output, repeatedly the time determination error of range observation all is not more than 1 sampling period T
s
Claims (8)
1. synchronous range finding system, this system comprises:
One main control computer is used for controlling and provide man-machine operation interface and interface to each integrated circuit board of system;
One digital signal processor is used for sending the active probe signal by digital/analog converter to the detectable signal transmitting and receiving device, receives sampled data, the processing target echoed signal of analog/digital converter simultaneously;
One digital/analog converter links to each other with digital signal processor by transmission data in real time port; Be used for the digital signal that digital signal processor sends is converted to simulating signal, and this simulating signal is sent to the detectable signal transmitting and receiving device;
One detectable signal transmitting and receiving device is used for the transmitting instructions active probe signal according to digital signal processor, and the receiving target echoed signal; And
One analog/digital converter links to each other with digital signal processor by transmission data in real time port; Be used to gather the target echo signal that the detectable signal transmitting and receiving device receives, this target echo signal be converted to digital signal, and this digital signal is sent to digital signal processor processes;
It is characterized in that in all the range finding cycles in whole ranging process, described digital/analog converter and analog/digital converter are in the continuous firing state; When digital/analog converter and analog/digital converter adopt same clock signal to carry out range-viewfinder, the inversion frequency F of described digital/analog converter
S1Inversion frequency F with analog/digital converter
S2, satisfy the integral multiple relation, that is: F
S1=nF
S2Or F
S2=nF
S1, wherein, n is the integral multiple divide ratio;
In each detect cycle, digital signal processor receives the sampled data of analog/digital converter continuously, if digital signal processor detects target echo signal from sampled data, then digital signal processor is handled sampled data, finishes the range finding location to target; If do not detect target echo signal, then directly abandon this sampled data.
2. synchronous range finding according to claim 1 system is characterized in that described transmission data in real time port is Link, UART or USB port.
3. synchronous range finding according to claim 1 system, it is characterized in that described same clock signal is by following: (a) being sent to any mode that analog/digital converter, (b) be sent to digital/analog converter or (c) sent to digital/analog converter and analog/digital converter simultaneously by external clock reference by analog/digital converter by digital/analog converter provides.
4. synchronous range finding according to claim 1 system is characterized in that described detectable signal transmitting and receiving device is active sonar equipment or radar.
5. synchronous range finding method, concrete steps comprise:
(1) main control computer is to digital/analog converter with analog/digital converter enables and initialization operation; Digital/analog converter and analog/digital converter are driven by same clock signal, are ready; The inversion frequency F of digital/analog converter
S1Inversion frequency F with analog/digital converter
S2Satisfy the integral multiple relation, that is: F
S1=nF
S2Or F
S2=nF
S1, wherein, n is the integral multiple divide ratio;
(2) digital signal processor sends complete ' 0 ' Frame by transmission data in real time port to digital/analog converter, and digital/analog converter carries out the digital-to-analog conversion; Simultaneously, analog/digital converter begins to carry out analog-digital conversion, and sampled data is sent to digital signal processor by transmission data in real time port; In all range finding cycles of whole ranging process, digital/analog converter and analog/digital converter are in the continuous firing state;
(3) enter a detect cycle after, digital signal processor stops to send complete ' 0 ' Frame, begins the active probe signal is sent to digital/analog converter; After transmission finishes, continue to send complete ' 0 ' Frame;
(4) digital/analog converter becomes simulating signal with the active probe conversion of signals, and sends simulating signal to the detectable signal transmitting and receiving device; The signal transmitting and receiving device is received instruction back emission active probe signal, and receiving target echoed signal, send target echo signal to analog/digital converter, analog/digital converter converts the target echo signal that receives to digital signal, and sends this digital signal to digital signal processor;
(5) digital signal processor receives the sampled data of analog/digital converter continuously, if digital signal processor detects target echo signal from sampled data, then digital signal processor is handled this sampled data, finishes the range finding location to target; If do not detect target echo signal, then directly abandon this sampled data.
6. synchronous range finding method according to claim 5 is characterized in that, described transmission data in real time port is Link, UART or USB port.
7. synchronous range finding method according to claim 5, it is characterized in that described same clock signal is by following: (a) being sent to any mode that analog/digital converter, (b) be sent to digital/analog converter or (c) sent to digital/analog converter and analog/digital converter simultaneously by external clock reference by analog/digital converter by digital/analog converter provides.
8. synchronous range finding method according to claim 5 is characterized in that, described detectable signal transmitting and receiving device is active sonar equipment or radar.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008102263701A CN101644775B (en) | 2008-11-14 | 2008-11-14 | Synchronous ranging system and synchronous ranging method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008102263701A CN101644775B (en) | 2008-11-14 | 2008-11-14 | Synchronous ranging system and synchronous ranging method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101644775A CN101644775A (en) | 2010-02-10 |
| CN101644775B true CN101644775B (en) | 2011-11-09 |
Family
ID=41656738
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008102263701A Expired - Fee Related CN101644775B (en) | 2008-11-14 | 2008-11-14 | Synchronous ranging system and synchronous ranging method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101644775B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115396502B (en) * | 2022-08-24 | 2024-04-16 | 中国银行股份有限公司 | Multi-system message time conversion method and device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1942781A (en) * | 2004-05-11 | 2007-04-04 | 株式会社村田制作所 | Radar system |
| CN1971649A (en) * | 2006-12-01 | 2007-05-30 | 哈尔滨工程大学 | Positioning and communicating integral buoy |
| CN1971305A (en) * | 2006-12-01 | 2007-05-30 | 哈尔滨工程大学 | Intelligent responder of deep water |
| CN1987516A (en) * | 2007-02-27 | 2007-06-27 | 呼秀山 | Equivalent sampling pulse distance measuring laser system |
-
2008
- 2008-11-14 CN CN2008102263701A patent/CN101644775B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1942781A (en) * | 2004-05-11 | 2007-04-04 | 株式会社村田制作所 | Radar system |
| CN1971649A (en) * | 2006-12-01 | 2007-05-30 | 哈尔滨工程大学 | Positioning and communicating integral buoy |
| CN1971305A (en) * | 2006-12-01 | 2007-05-30 | 哈尔滨工程大学 | Intelligent responder of deep water |
| CN1987516A (en) * | 2007-02-27 | 2007-06-27 | 呼秀山 | Equivalent sampling pulse distance measuring laser system |
Non-Patent Citations (1)
| Title |
|---|
| JP特开2006-226711A 2006.08.31 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101644775A (en) | 2010-02-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107015230B (en) | ultrasonic ranging method | |
| CN1508563A (en) | Meteorological radar set | |
| CN105406611A (en) | Device and method of determining through-metal wall ultrasonic sound wireless energy transmission channel optimization frequency | |
| CN101799545A (en) | Ultrasonic based dynamic distance measurement method and system | |
| CN101813528B (en) | Method for precisely measuring temperature by using ultrasonic technology and measuring instrument | |
| CN204347059U (en) | A kind of multiple-input and multiple-output arrayed ultrasonic wind measuring system | |
| CN104569484A (en) | Multi-input multi-output array type ultrasound anemometry system and method | |
| CN101644775B (en) | Synchronous ranging system and synchronous ranging method | |
| US4084148A (en) | Object recognition system | |
| CN201255644Y (en) | Synchronous transceiving time difference type supersonic flowmeter | |
| CN203037849U (en) | Ultrasonic thickness gauge | |
| CN2784945Y (en) | Ultrasonic distance-measuring sensor | |
| CN100489557C (en) | Method and device for measuring flying time of signal by using composite phase discrimination | |
| CN204988220U (en) | Bridge moves amount of deflection measurement system based on ultrasonic wave principle | |
| CN107219530A (en) | The automobile ultrasonic radar system continuously received and dispatched | |
| CN206960652U (en) | The automobile ultrasonic radar system continuously received and dispatched | |
| CN1924607B (en) | Method for controlling multiple working conditions high frequency radar receiver | |
| CN102519551A (en) | Ultrasonic liquid level measurer based on pseudo code relevant technology | |
| CN107607616B (en) | Wireless sound wave detection device and method | |
| CN103472452B (en) | A kind of multichannel ultrasonic sensing system method for quick and system | |
| CN107450077A (en) | Supersonic range finder and method and associated aircraft | |
| CN201444295U (en) | Electronic whiteboard system based on host processing | |
| CN102564533A (en) | Ultrasonic liquid level measuring method based on pseudo-code correlation technique | |
| CN103364779A (en) | Fixed forwarding strength-based target echo wave strength measurement method and fixed forwarding strength-based target echo wave strength measurement system | |
| CN105136075A (en) | Bridge dynamic deflection measurement system and method based on ultrasonic principle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20111109 Termination date: 20141114 |
|
| EXPY | Termination of patent right or utility model |