CN100470258C - Method and device for measuring the distance by ultrasonic waves - Google Patents
Method and device for measuring the distance by ultrasonic waves Download PDFInfo
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- CN100470258C CN100470258C CNB2006101511480A CN200610151148A CN100470258C CN 100470258 C CN100470258 C CN 100470258C CN B2006101511480 A CNB2006101511480 A CN B2006101511480A CN 200610151148 A CN200610151148 A CN 200610151148A CN 100470258 C CN100470258 C CN 100470258C
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Abstract
This invention relates to one supersonic wave measurement distance method and device, which comprises the following steps: sending measurement signals; receiving echo wave signals; echo signal filter amplifying processing; storing the A/D conversion and its results on echo signals; comparing the test wave signal and peak value signals; according to comparison results stopping A/d samples; analyzing stored A/d conversion result data and finding echo oscillator point; according to conversion speed to compute echo time to get measurement distance.
Description
Technical field
The present invention relates to a kind of method and device of measuring distance, be specifically related to use the method and the device of ultrasonic measurement distance.
Background technology
Because the directive property that has of ultrasound wave distance strong, that propagate in medium is far away, be easy to characteristic such as control, has been applied to the field of range observation widely.Existing ultrasound wave span from method, all be to send ultrasound wave by measurement to calculate measured distance with receiving the mistiming of echo, affirmation receives the order of accuarcy of the time of echo, it is the key factor that influences the measuring distance precision, but that adopts at present determines to receive in the method for echo, mostly be to confirm the echo time by the rising edge of comparator circuit judgement echo, in order to eliminate the influence of clutter, in comparator circuit, all be provided with threshold level, the moment that is higher than this threshold level when the signal that receives, just think to receive the moment of echo, but in fact this is more late than the echo time that actual reception arrives constantly, this mistiming has influenced the precision of measuring, if improve measuring accuracy, just needs to shorten this mistiming, just reduce threshold level, but threshold level is low excessively, can cause clutter is used as the misoperation of echoed signal again, and this just makes the precision of present ultrasonic measurement distance be restricted.
Summary of the invention
In the method that solves present ultrasonic measurement distance, owing to receiving the inaccurate problem that influences measuring accuracy of echo time affirmation, the present invention has designed a kind of method of ultrasonic measurement distance, and it comprises:
Steps A 1: system initialization;
Steps A 2: send ultrasonic signal S1;
Steps A 3: timer picks up counting;
Steps A 4: receive echoed signal;
Steps A 5: echoed signal is carried out filtering, program control amplification, the echoed signal S2 that obtains amplifying;
Steps A 6: gather the echoed signal S2 that amplifies, carry out the A/D conversion, and the storage transformation result;
Steps A 7: the echoed signal S2 that amplifies is carried out detection and peak value respectively keep handling, obtain rectified signal S3 and peak signal S4;
Steps A 8: the partial pressure value Vf with peak signal S4 compares as reference voltage and rectified signal S3, obtain level signal S5, when the value of rectified signal S3 during greater than the partial pressure value Vf of peak signal S4, obtain high level signal, when the value of rectified signal S3 during, obtain low level signal less than the partial pressure value Vf of peak signal S4;
Steps A 9: judge that pulse signal S5 is a high level signal? if judged result is for being, execution in step A10 then is if judged result is then returned execution in step A4 for not;
Steps A 10: the record timer time is tr1;
Steps A 11: gather the echoed signal S2 that amplifies, carry out the A/D conversion, and the storage transformation result;
Steps A 12: judge whether the timer time surpasses (tr1+ Δ T)? if judged result is for being, execution in step A13 then, if judged result for not, execution in step A11 then;
Steps A 13: finish A/D conversion to the echoed signal of amplifying;
Steps A 14: the A/D transformation result of analyzing stored, seek the echo oscillation starting points;
Steps A 15: according to the slewing rate of A/D change-over circuit, calculate the time of oscillation starting points, obtain the distance of measuring.Δ T described in the steps A 12 is 20 to 40 ultrasound wave cycles of ultrasonic generator ultrasonic waves transmitted.
The device of realizing the ultrasonic measurement distance of this method comprises cpu control circuit, the emission driving circuit, ultrasonic generator, ultrasonic receiver, filtering circuit, programmable amplifying circuit, detecting circuit, peak holding circuit, comparator circuit, the A/D change-over circuit, the input end of described emission driving circuit is connected with the output terminal of cpu control circuit, the output terminal of emission driving circuit is connected with the input point of ultrasonic generator, the output terminal of ultrasonic receiver is connected with the input end of filtering circuit, the output terminal of filtering circuit is connected with the input end of programmable amplifying circuit, the control end of programmable amplifying circuit is connected with the control output end of cpu control circuit, the signal output part of programmable amplifying circuit and the signal input part of detecting circuit, the analog input end of the signal input part of peak holding circuit and A/D change-over circuit connects, the signal output part of detecting circuit and peak holding circuit is connected with an input end of comparator circuit respectively, the signal output part of comparator circuit is connected with the signal input part of cpu control circuit, and the digital signal output bus of A/D change-over circuit is connected with the data bus and the signal output part of cpu control circuit respectively with signal input end.
The method of ultrasonic measurement distance of the present invention can be determined the echo time of reception accurately, and then improves the measuring accuracy of distance.
Description of drawings
Fig. 1 is the structural drawing of the device of ultrasonic measurement distance of the present invention, Fig. 2 is the structural drawing of the device of embodiment four and five described ultrasonic measurement distances, Fig. 3 is the method flow diagram of ultrasonic measurement distance of the present invention, Fig. 4 is the method flow diagram that the described ultrasound waves of embodiment two are surveyed the reason distances, and Fig. 5 is the waveform synoptic diagram in each stage in the method for ultrasonic measurement distance of the present invention.
Embodiment
Embodiment one: present embodiment is described referring to Fig. 1, Fig. 3, Fig. 5.The method of the ultrasonic measurement distance of present embodiment comprises:
Steps A 1: system initialization;
Steps A 2: send ultrasonic signal S1;
Steps A 3: timer picks up counting;
Steps A 4: receive echoed signal;
Steps A 5: echoed signal is carried out filtering, program control amplification, the echoed signal S2 that obtains amplifying;
Steps A 6: gather the echoed signal S2 that amplifies, carry out the A/D conversion, and the storage transformation result;
Steps A 7: the echoed signal S2 that amplifies is carried out detection and peak value respectively keep handling, obtain rectified signal S3 and peak signal S4;
Steps A 8: the partial pressure value Vf with peak signal S4 compares as reference voltage and rectified signal S3, obtain level signal S5, when the value of rectified signal S3 during greater than the partial pressure value Vf of peak signal S4, obtain high level signal, when the value of rectified signal S3 during, obtain low level signal less than the partial pressure value Vf of peak signal S4;
Steps A 9: judge that pulse signal S5 is a high level signal? if judged result is for being, execution in step A10 then is if judged result is then returned execution in step A4 for not;
Steps A 10: the record timer time is tr1;
Steps A 11: gather the echoed signal S2 that amplifies, carry out the A/D conversion, and the storage transformation result;
Steps A 12: judge whether the timer time surpasses (tr1+ Δ T)? if judged result is for being, execution in step A13 then, if judged result for not, execution in step A11 then;
Steps A 13: finish A/D conversion to the echoed signal of amplifying;
Steps A 14: the A/D transformation result of analyzing stored, seek the echo oscillation starting points;
Steps A 15: according to the slewing rate of A/D change-over circuit, calculate the time of oscillation starting points, obtain the distance that measures.
Referring to Fig. 1, the device of the ultrasonic measurement distance of realization present embodiment is by cpu control circuit 1, emission driving circuit 2, ultrasonic generator 3, ultrasonic receiver 4, filtering circuit 5, programmable amplifying circuit 6, detecting circuit 7, peak holding circuit 8, comparator circuit 10, A/D change-over circuit 9 is formed, the input end of described emission driving circuit 2 is connected with the output terminal of cpu control circuit 1, the output terminal of emission driving circuit 2 is connected with the input end of ultrasonic generator 3, the output terminal of ultrasonic receiver 4 is connected with the input end of filtering circuit 5, the output terminal of filtering circuit 5 is connected with the input end of programmable amplifying circuit 6, the control end of programmable amplifying circuit 6 is connected with the control output end of cpu control circuit 1, the signal input part of the signal output part of programmable amplifying circuit 6 and detecting circuit 7, the analog input end of the signal input part of peak holding circuit 8 and A/D change-over circuit 9 connects, the signal output part of detecting circuit 7 and peak holding circuit 8 is connected with an input end of comparator circuit 10 respectively, the signal output part of comparator circuit 10 is connected with the signal input part of cpu control circuit 1, described comparator circuit 1 is that the output signal S3 of the voltage division signal of output signal S2 of peak holding circuit 8 that will input and detecting circuit 7 compares and obtains level signal S5, and the digital signal output bus of A/D change-over circuit 9 is connected with the data bus and the signal output part of cpu control circuit 1 respectively with signal input end.
In the present embodiment, cpu control circuit 1 is made up of LPC2214, EPM7128, ISS125616, emission driving circuit 2 adopts metal-oxide-semiconductor IRF630, it is the piezoelectric ceramic ultrasound transducer of 40kHz that ultrasonic generator 3 and ultrasonic receiver 4 adopt frequency, filtering circuit 5 adopts MAX275, and detecting circuit 7 and peak holding circuit 8 adopt OP37, and comparator circuit 10 adopts LM393, A/D change-over circuit 9 adopts AD7892, and programmable amplifying circuit 6 adopts OP37 and program control potentiometer X9313.
Referring to Fig. 5, the waveform signal of described ultrasonic generator 3 outputs is the S1 that transmits, the echoed signal S2 of the output signal of described programmable amplifying circuit 6 for amplifying, the output signal of described detecting circuit 7 is rectified signal S3, the output signal of described peak holding circuit 8 is peak signal S4, and voltage division signal Vf and rectified signal S3 that described comparator circuit 10 is got the crest voltage Vp of peak holding circuit 10 outputs compare outputs level signals S5.In steps A 6 and steps A 10, the echoed signal S2 of 9 pairs of amplifications of A/D change-over circuit samples, adopt respectively data a (0), a (1), a (2) ... a (m+n), up to steps A 13, finish the A/D sampling.
At the Δ T described in the described steps A 12 is the time in 20 to 40 cycles of ultrasonic generator 3 ultrasonic waves transmitted.
In described steps A 14, the method for seeking the echo oscillation starting points is: the A/D transformation result data of having stored are analyzed, begin to seek the oscillation starting points of the initial data of first group of continuous data that increase tendency arranged as echo from first data.
The process that present embodiment is sought the echo oscillation starting points is: begin comparison from first data a (0) of A/D transformation result, all be data near zero, up to data a (n+1), a (n+2) ... beginning, data have the trend that increases gradually, can decision data a (n+1) the data a in front (n) be the echo oscillation starting points then.
In steps A 15, according to the inversion frequency f of A/D change-over circuit, calculate the time that collects a (n) data: t=n/f, then " t " is hyperacoustic echo time of measuring distance.
Adopt method of the present invention to confirm that the maximum error of time of the oscillation starting points of echo depends on the speed of A/D conversion.The slewing rate of the A/D change-over circuit that adopts in the present embodiment is 500kHz, differ 2 μ s between then per two data points, oscillation starting points that then searches out and actual oscillation starting points differ at most ± 1 data, hyperacoustic speed is 340m/s, and the distance that then calculates differs at most with actual range ± 0.34mm.If the slewing rate of the A/D change-over circuit that adopts is 1MHz, then measuring error is ± 0.17mm.
Embodiment two: referring to Fig. 4 present embodiment is described, is with the difference of the method for the ultrasonic measurement distance of embodiment one, in steps A 9, if judged result for not, is then carried out following steps B1:
Step B1: judge that whether the timer time surpass fixed time Tr, if judged result is for being, execution in step B2 then; If judged result is then returned execution in step A4 for not;
Step B2: finish the A/D conversion, revise the multiple of programmable amplifier according to the A/D translation data of storage;
Step B3: remove the A/D collection result of having stored, return steps A 2.
In the present embodiment, increased peaked qualification of echo time, when the time of waiting for pulse signal S5 surpasses fixed time Tr, a little less than thinking that echoed signal too, measure failure, according to the maximal value in the A/D object information of gathering and storing, increase the multiple of programmable amplifier, measure again then.
Described fixed time Tr sets according to the range of the device of ultrasonic measurement distance, and when the range of the device of ultrasonic measurement distance was X, Tr was greater than or equal to ultrasound wave and comes and goes the used time of distance X.
The method of the ultrasonic measurement distance of present embodiment can be according to the strong and weak situation of echoed signal, i.e. the size cases of the distance of Ce Lianging is adjusted the enlargement factor of echoed signal automatically, has not only enlarged measurement range and has also improved the accuracy of measuring.
Embodiment three: be with the difference of the method for embodiment one or two ultrasonic measurement distance, after steps A 15, increased steps A 16:, the distance that calculates is revised according to the situation of ambient temperature.
The difference of the device of describing in the device of the method for the ultrasonic measurement distance of realization present embodiment and the embodiment one is, increased temperature measuring circuit 10, the signal output part of temperature measuring circuit 10 is connected with the signal input part of cpu control circuit 1.
The ultrasonic wave measuring method of present embodiment has the temperature debugging functions, can revise the result who measures according to the temperature of external environment.
Embodiment four: referring to Fig. 2, the difference of the device of the device of the ultrasonic measurement distance of present embodiment and embodiment one described ultrasonic measurement distance is, display circuit 11 and keyboard circuit 12 have been increased, the signal input part of described display circuit 11 is connected with the signal output part of cpu control circuit 1, and the signal output part of keyboard circuit 12 is connected with the signal input part of cpu control circuit 1.
The device of the ultrasonic measurement distance of present embodiment has increased Presentation Function and button input function.
Embodiment five: referring to Fig. 2, the difference of the device of the device of the ultrasonic measurement distance of present embodiment and embodiment one described ultrasonic measurement distance is that the signal input part that has increased voice broadcast circuit 13 is connected with the signal output part of cpu control circuit 1.
The device of the ultrasonic measurement distance of present embodiment has increased voice broadcast function.
Claims (9)
1, a kind of method of ultrasonic measurement distance is characterized in that it comprises step:
Steps A 1: system initialization;
Steps A 2: send ultrasonic signal (S1);
Steps A 3: timer picks up counting;
Steps A 4: receive echoed signal;
Steps A 5: echo waveform is carried out filtering, program control amplification, the ripple signal (S2) that obtains amplifying back;
Steps A 6: gather the echoed signal (S2) of amplifying, carry out the A/D conversion, and the storage transformation result;
Steps A 7: the echoed signal (S2) of amplifying is carried out detection and peak value respectively keep handling, obtain rectified signal (S3) and peak signal (S4);
Steps A 8: the partial pressure value Vf with peak signal (S4) compares as reference voltage and rectified signal (S3), obtain level signal (S5), when the value of rectified signal (S3) during greater than the partial pressure value Vf of peak signal (S4), obtain high level signal, when the value of rectified signal (S3) during, obtain low level signal less than the partial pressure value Vf of peak signal (S4);
Steps A 9: judge whether pulse signal (S5) is high level signal, if judged result is for being, execution in step A10 then is if judged result is then returned execution in step A4 for not;
Steps A 10: record timer time tr1;
Steps A 11: gather the echoed signal (S2) of amplifying, carry out the A/D conversion, and the storage transformation result;
Steps A 12: judge that whether the timer time surpass (tr1+ Δ T), if judged result is for being, execution in step A13 then, if judged result for denying, execution in step A11 then;
Steps A 13: finish A/D conversion to the echoed signal of amplifying;
Steps A 14: the A/D transformation result of analyzing stored, seek the echo oscillation starting points;
Steps A 15: according to the slewing rate of A/D change-over circuit, calculate the time of oscillation starting points, obtain the distance that measures;
Δ T described in the steps A 12 is 20 to 40 ultrasound wave cycles of ultrasonic generator (3) ultrasonic waves transmitted.
2, the method for ultrasonic measurement distance according to claim 1, it is characterized in that in the steps A 14, the method of seeking the echo oscillation starting points is: the A/D transformation result data of having stored are analyzed, seek the oscillation starting points of the initial data of the data set that increase tendency is arranged as echo.
3, the method for ultrasonic measurement distance according to claim 1 is characterized in that, in steps A 9, if judged result is not, then carries out following steps:
Step B1: judge that whether the timer time surpass fixed time Tr, if judged result is for being, execution in step B2 then; If judged result is not, then execution in step A4;
Step B2: finish the A/D conversion, revise the multiple of programmable amplifier according to the A/D translation data of storage;
Step B3: remove the A/D transformation result of having stored, return execution in step A2.
4, the method for ultrasonic measurement distance according to claim 4 is characterized in that, the fixed time Tr described in the step B1 is the used time of maximum range that comes and goes measured distance more than or equal to ultrasound wave.
5, according to the method for the described ultrasonic measurement distance of arbitrary claim in the claim 1 to 5, it is characterized in that also comprising steps A 16 after steps A 15: according to the situation of ambient temperature, pair pitch parameters is revised.
6, be used to realize the device of the method for the described ultrasonic measurement distance of the arbitrary claim of claim 1 to 4, it is characterized in that it comprises cpu control circuit (1), emission driving circuit (2), ultrasonic generator (3), ultrasonic receiver (4), filtering circuit (5), programmable amplifying circuit (6), detecting circuit (7), peak holding circuit (8), comparator circuit (10), A/D change-over circuit (9), the input end of described emission driving circuit (2) is connected with the output terminal of cpu control circuit (1), the output terminal of emission driving circuit (2) is connected with the input end of ultrasonic generator (3), the output terminal of ultrasonic receiver (4) is connected with the input end of filtering circuit (5), the output terminal of filtering circuit (5) is connected with the input end of programmable amplifying circuit (6), the control end of programmable amplifying circuit (6) is connected with the control output end of cpu control circuit (1), the signal input part of the signal output part of programmable amplifying circuit (6) and detecting circuit (7), the analog input end of the signal input part of peak holding circuit (8) and A/D change-over circuit (9) connects, the signal output part of detecting circuit (7) and peak holding circuit (8) is connected with an input end of comparator circuit (10) respectively, the signal output part of comparator circuit (10) is connected with the signal input part of cpu control circuit (1), and the digital signal output bus of A/D change-over circuit (9) is connected with the data bus and the signal output part of cpu control circuit (1) respectively with signal input end.
7, the device of ultrasonic measurement distance according to claim 7 is characterized in that it also comprises temperature measuring circuit (10), and the signal output part of temperature measuring circuit (10) is connected with the signal input part of cpu control circuit (1).
8, the device of ultrasonic measurement distance according to claim 7, it is characterized in that it also comprises display circuit (11) and keyboard circuit (12), the signal input part of described display circuit (11) is connected with the signal output part of cpu control circuit (1), and the signal output part of keyboard circuit (12) is connected with the signal input part of cpu control circuit (1).
9, the device of ultrasonic measurement distance according to claim 7 is characterized in that it also comprises voice broadcast circuit (13), and the signal input part of described voice broadcast circuit (13) is connected with the signal output part of cpu control circuit (1).
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| CNB2006101511480A CN100470258C (en) | 2006-12-15 | 2006-12-15 | Method and device for measuring the distance by ultrasonic waves |
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| CNB2006101511480A CN100470258C (en) | 2006-12-15 | 2006-12-15 | Method and device for measuring the distance by ultrasonic waves |
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Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101782648B (en) * | 2010-03-05 | 2013-03-27 | 圆展科技股份有限公司 | Ultrasonic wave receiving module, detecting system as well as detecting method and physical camera thereof |
| CN102445694A (en) * | 2011-09-20 | 2012-05-09 | 中南大学 | Navigation robot obstacle detection method and system |
| CN104931971A (en) * | 2015-06-19 | 2015-09-23 | 上海美迪索科电子科技有限公司 | Ultrasonic ranging method and ranging device for wireless ranging |
| CN110366690A (en) * | 2018-02-11 | 2019-10-22 | 深圳市大疆创新科技有限公司 | Integrated circuit and system for measuring distance |
| JP7040766B2 (en) * | 2018-03-29 | 2022-03-23 | 株式会社ブイ・テクノロジー | Ultrasonic distance measuring device and ultrasonic distance measuring method |
| CN110045379B (en) * | 2019-04-11 | 2023-03-31 | 花瓣云科技有限公司 | Distance measuring method, related equipment and system |
| CN111007517A (en) * | 2019-12-24 | 2020-04-14 | 芜湖美的厨卫电器制造有限公司 | Method and device for detecting ultrasonic waves, distance detection equipment and water dispenser |
| CN111007516A (en) * | 2019-12-24 | 2020-04-14 | 芜湖美的厨卫电器制造有限公司 | Method and device for detecting ultrasonic waves, distance detection equipment and water dispenser |
| CN113616916A (en) * | 2021-09-14 | 2021-11-09 | 深圳市鑫辉微电子有限公司 | Remote auto-induction temperature measurement hand washing and sterilizing integrated machine |
| CN114451230B (en) * | 2022-03-01 | 2023-02-17 | 华清农业开发有限公司 | Planting method of moderate and severe saline-alkali soil water retention, salt resistance and carbon increase fertile soil |
| CN115058343B (en) * | 2022-08-16 | 2022-11-01 | 南京邦康生物技术有限公司 | Selenium-enriched yeast cell wall breaking method, controller and system based on ultrasonic waves |
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