CN202351429U - Laser phase method distance measuring device - Google Patents
Laser phase method distance measuring device Download PDFInfo
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- CN202351429U CN202351429U CN2011205227386U CN201120522738U CN202351429U CN 202351429 U CN202351429 U CN 202351429U CN 2011205227386 U CN2011205227386 U CN 2011205227386U CN 201120522738 U CN201120522738 U CN 201120522738U CN 202351429 U CN202351429 U CN 202351429U
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Abstract
The utility model discloses a laser phase method distance measuring device, comprising a laser emitting and electro-optical modulation module, an inner and outer optical path module and an electro-optical detection and data processing module, wherein the laser emitting and electro-optical modulation module is used for emitting infrared lasers modulated by a high frequency; the inner and outer optical path module comprises an inner optical path and an outer optical path; the infrared lasers are separately transmitted to the electro-optical detection and data processing module through the inner optical path and the outer optical path; and the electro-optical detection and data processing module is used for respectively carrying out conversion and frequency conversion treatment on two paths of transmitted optical signals to calculate a phase difference of the two paths of optical signals to obtain a distance value to be detected. According to the device disclosed by the utility model, lights sent by a laser device are directly conducted into an integrated electro-optical modulator through optical fibers, and outgoing beams are conducted to a focal point of a transmitting objective lens of a distance measuring meter through the optical fibers, so that the structure of the optical path is greatly simplified; and meanwhile, a modulating frequency of the integrated electro-optical modulator is far higher than a direct modulating frequency of the laser device, so that higher measuring precision can be achieved.
Description
Technical field
The utility model belongs to field of linear dimension measurement technology, is specifically related to a kind of laser distance measurement mechanism, is used for the measurement of target object to the absolute distance between the measurement mechanism.
Background technology
Laser phase method ranging technology is to come measuring distance through measuring the modulated laser phase change that causes of between testing distance, flying.In the medium or short range range finding, the factor that influences measuring accuracy mainly contains the relative error variation and the phase difference measurement error of modulating frequency.Under same Phase Difference Measuring Precision, the frequency that improves laser modulation signal can improve measuring accuracy.Present laser phase method stadimeter, generally at tens megahertzes to hundreds of megahertz, the range error of medium or short range stadimeter is generally greater than 1mm for its Laser Modulation frequency.The intensity modulation of laser mainly contains two kinds in the laser phase method stadimeter; A kind of is the working current that adopts directly modulated laser, thereby directly changes the luminous power of laser instrument, and another kind is with after the laser alignment; Feed electrooptic modulator, its emergent light will change with modulation voltage.The restriction of first method is that modulating frequency is lower, and the defective of second method is that light path is complicated, and volume is bigger, is difficult to adjustment, is unfavorable for practical application.
The utility model content
The purpose of the utility model is to propose a kind of ranging phase method device of laser; Radiofrequency signal with L-band is carried out electrooptical modulation to the integrated electro-optic modulator; The light that directly laser instrument is sent gets into the integrated electro-optic modulator through fiber optic conduction; The outgoing beam of integrated electro-optic modulator still arrives the along of stadimeter transmitting objective lens through fiber optic conduction, thereby has simplified light channel structure greatly, and the modulating frequency of integrated electro-optic modulator is far above the direct modulating frequency of laser instrument simultaneously; Therefore, can reach higher measuring accuracy.
The concrete technical scheme that purpose adopted that realizes the utility model is:
A kind of laser phase method distance measuring equipment comprises Laser emission and electrooptical modulation module, inside and outside light path module, photodetection and data processing module.Laser emission and electrooptical modulation module realize the infrared laser high frequency modulated to emission; Light path and outer light path two-way in laser after the modulation is divided into by inside and outside light path module; Photodetection and signal processing module are realized the optical signal detection to inside and outside light path, and the electric signal after surveying is handled the final output in back testing distance value.
Specifically; Laser emission and electrooptical modulation module are made up of laser instrument, radio-frequency signal generator, integrated electro-optic modulator; The infrared beam that laser instrument is launched directly gets into the integrated electro-optic modulator through optical fiber, and the radiofrequency signal that is produced by radio-frequency signal generator realizes intensity modulated to electrooptic modulator.
Inside and outside light path module comprises optical fiber splitter, be arranged on the collimation lens set of outer light path outgoing place of optical fiber splitter, be arranged on the catoptron at target to be measured place and be arranged on the lens combination at outer light path pick-up probe place.Signal after said optical fiber splitter will be modulated is divided into two-way: the one tunnel is interior light path, the corresponding photodetector of light path in this road directly gets into; Another road is outer light path, and directive is installed in the catoptron at target to be measured place behind the collimation lens set collimation, the corresponding photodetector of light path outside behind this mirror reflects back into optical fibers shunt place, being focused on by said focus lens group.
Photodetection and signal processing module comprise survey in photodetector, the photodetector of surveying outer light path, ASH part, the data acquisition and processing (DAP) display part partly and as a result of light path.Two detector two ways of optical signals that inside and outside light path is corresponding convert electric signal and amplification respectively into; The ASH part is current signal down coversion and filtering after amplifying, and the radiofrequency signal that will have noise becomes purer low frequency signal, so that high-precision phase difference measurement; Part of data acquisition is calculated the phase differential of inside and outside light path then through these two low frequency signals of double channel A/D element synchronous acquisition by the two ways of digital signals of gathering, just can calculate testing distance value and demonstration according to phase differential.
The utlity model has following advantage:
1 brings up to L-band (three frequencies about 1.5GHz) with the signal frequency of modulated laser, guarantees that simultaneously signal frequency has very high degree of stability, thereby has improved distance accuracy.
2 laser instruments are all used fiber optic conduction to modulator and modulator to inside and outside light path, have simplified the structure of front end light path system.
The timesharing of 3 usefulness controllers control fractional frequency-division phase-locked loop produces three radiofrequency signals of the integrated electrooptic modulator of modulation, and it is simple in structure, and phase noise is low.
4 adopt the circuit timesharing radiofrequency signal that inside and outside light path is corresponding of equity to be down-converted to the low frequency signal of same frequency synchronously, help to simplify after the detection signal processing circuit with reduce measuring error.
Description of drawings
Fig. 1 is the principle schematic of laser phase method distance measuring equipment.
Fig. 2 is the synoptic diagram of radio-frequency signal generator.
Fig. 3 is the synoptic diagram of signal Processing after the laser range finder photodetection
Embodiment
Do further to specify below in conjunction with accompanying drawing.
The principle schematic of the laser phase method distance measuring equipment of the utility model is as shown in Figure 1.The infrared laser that laser instrument 1 sends directly gets into electrooptic modulator 3 through optical fiber 2; The signal of 3 L-bands (1.485GHz, 1.49925GHz, 1.5GHz) is sent in driver unit 4 timesharing of radio-frequency signal generator, is loaded into electrooptic modulator 3 after this signal is amplified to enough power and filtering.
Light signal to after electrooptic modulator 3 modulation is divided into two-way through optical fiber splitter 5, and bringing out what penetrate by A a road is outer light path, and bringing out what penetrate by B a road is interior light path.The light signal of interior light path is (PIN+TIA) 9 from the fiber optic conduction to the photodetector directly.The optical signals fiber optic conduction of outer light path is to the along of collimation lens set 6; Directive is arranged on the catoptron 7 at object under test place behind collimation lens set 6 collimations; By getting back to receiving objective group 8 after 7 reflections of this catoptron, receiving objective group 8 focuses on the laggard photodetector (APD+TIA) 10 of going into the light signal of outer light path.Detector 9 and 10 light signals with inside and outside light path are separately converted to electric signal and amplify.
The master that electrooptic modulator is modulated shakes 4 according to indirect modulation frequency mode assigned frequency, and the frequency of the winner is shaken three L-bands that timesharing sends all changes in very little scope, is convenient to same circuit filtering of following adopted and amplification.Three indirect modulation frequencies that timesharing is sent can guarantee the measurement range of 200m, can guarantee the Measurement Resolution of 0.1mm again.
The synoptic diagram of radio-frequency signal generator is as shown in Figure 2, the master among Fig. 1 shake 4 with Fig. 3 in local oscillator 20 all adopt the structure of Fig. 2.Radio-frequency signal generator comprises controller 15, fractional frequency-division phase-locked loop 13, power supply 14, crystal oscillator 12, low noise amplifier 16, BPF. 17.Controller 15 (preferentially select for use and adopt single chip computer AT 89LS52) writes size and the frequency conversion time of control word with controlled frequency to fractional frequency-division phase-locked loop 13 (preferentially selecting ADF4350 for use); This controller 15 is frequency conversion time of the local oscillator in the control chart 3 simultaneously also, make the winner shake 4 with local oscillator 20 synchronous frequency conversions.The power supply 14 of ultra-low noise (preferentially selecting ADP150 for use) is to fractional frequency-division phase-locked loop 13 power supplies, and crystal oscillator 12 employing temperature compensating crystal oscillator or the constant-temperature crystal oscillators as reference frequency source help to improve frequency stability.The short-term stability of radiofrequency signal is guaranteed by the fractional frequency-division phase-locked loop circuit that mainly long-term stability is mainly guaranteed by temperature compensating crystal oscillator or constant-temperature crystal oscillator.The signal of fractional frequency-division phase-locked loop 13 outputs is amplified by low noise amplifier 16 (preferentially selecting HMC719 for use), and is last by on the integrated electro-optic modulator 3 that is loaded into after BPF. 17 filtering among Fig. 1.
Early stage laser phase method stadimeter adopts the method for frequency multiplication to a plurality of crystal oscillators, frequency division, mixing to produce modulation signal, this method complex structure, and debug difficulties is seldom used now.The method that present laser phase method stadimeter produces modulating frequency has Direct Digital synthetic method (DDS) and indirect synthesis method of the frequency (PLL).Under the present technology, the frequency of the signal that the DDS method produces is no more than 1GHz, and PLL also can be referred to as the integral frequency divisioil phaselocked loop, though this method can produce very high-frequency signal, its frequency resolution is lower, and the frequency hopping time is long.The fractional frequency-division phase-locked loop that occurs in recent years is applied in the Laser Range Finding Based on Phase, can guarantees higher frequency stability and frequency resolution, the short frequency hopping time is arranged again, and it is simple in structure, be convenient to debugging.
The ASH of said photodetection and signal processing module partly comprises two wave filters 18 and 19, local oscillator 20 and binary channels frequency mixer 21.The synoptic diagram of signal Processing is as shown in Figure 3 after the photodetection; The radiofrequency signal after binary channels frequency mixer 21 is surveyed inside and outside light path and the signal mixing (down coversion) of local oscillator 20; Just become low frequency signal to the corresponding high-frequency signal of inside and outside light path through mixing; Calculate the phase differential of these low frequency signals, finally calculate testing distance according to phasometer.Specifically, the electric signal of photodetector 9 outputs that interior light path is corresponding obtains purer radiofrequency signal C by the unnecessary harmonic components of wave filter 18 filterings.The electric signal of photodetector 10 outputs that outer light path is corresponding obtains purer radiofrequency signal D by wave filter 19 filtering.Because the signal that 1.485GHz, 1.49925GHz, 1.5GHz are sent in the main timesharing of shaking of controller 15 control is modulated integrated electrooptic modulator, so signal C, also saltus step between these three frequencies synchronously of D, just phase differential is different.Controller 15 is also controlled the radiofrequency signal E that three frequencies are sent in local oscillator 20 timesharing, and three frequencies of signal E are respectively than the low same fixed value of three frequencies of the main signal that shakes, and with signal C, D synchronising frequency hopping.Signal C, D and signal E be down coversion in binary channels frequency mixer 21 (preferentially selecting ADL5802 for use); The frequency identical (like 1MHz) of different three pairs of low frequency signals constantly after the down coversion; All equal the difference of frequency of frequency and the signal E of signal C, D, but the phase differential of every pair of signal is different.Behind double channel A/every pair of signal of D device 22 synchronous acquisition, calculate the phase differential of every pair of low frequency signal by phase difference calculating device 23, the phase differential of inside and outside light path just just can calculate testing distance according to the phase differential of these 3 pairs of signals.
The environmental change meeting causes the variation of circuit parameter, thereby produces the additional phase error of inside and outside light path respective signal.For reducing this instantaneous additional phase error, on the signal Processing of inside and outside light path, adopt the circuit arrangement mode of equity, down coversion device and A/D sampler all adopt the binary channels device.Can draw light path and the medium-term and long-term constant fixing additional phase error of circuit through demarcating, it is eliminated as definite value property systematic error in routine processes.
Claims (8)
1. laser phase method distance measuring equipment; Comprise Laser emission and electrooptical modulation module, inside and outside light path module and photodetection and data processing module, wherein; Said Laser emission and electrooptical modulation module are used to launch the infrared laser through high frequency modulated; Light path and outer light path in said inside and outside light path module comprises, said infrared laser through said in light path with outside light path separate transmission, the infrared laser of outer light path is sent to said photodetection and signal processing module after object under test is found range; The infrared laser of interior light path directly is sent to said photodetection and signal processing module; This photodetection and signal processing module are changed respectively and frequency-conversion processing the two ways of optical signals that transmits, and calculate the phase differential of two ways of optical signals, can obtain the testing distance value.
2. device according to claim 1; It is characterized in that; Described photodetection and signal processing module comprise the photodetector (9) of surveying interior light path, photodetector (10), the ASH part of surveying outer light path, and the data acquisition and processing (DAP) part;
Wherein, two photodetectors (9,10) convert the light signal of inside and outside light path transmission into electric signal and amplification respectively; Electric signal after said ASH part is amplified two-way carries out down coversion and filtering respectively; All convert low frequency signal into; Said part of data acquisition is through these two low frequency signals of double channel A/D element synchronous acquisition; Calculate the phase differential of inside and outside light path light signal then by these two low frequency signals, can calculate the testing distance value according to this phase differential.
3. device according to claim 2; It is characterized in that; Said ASH partly comprises two filter (18; 19), local oscillator (20) and binary channels frequency mixer (21), the electric signal after this binary channels frequency mixer (21) amplifies said two-way and the signal mixing of local oscillator (20) can be realized this two paths of signals is all become low frequency signal.
4. according to the described device of one of claim 1-3; It is characterized in that; Said Laser emission and electrooptical modulation module comprise laser instrument (1), radio-frequency signal generator and integrated electro-optic modulator (3); Said laser instrument (1) emission infrared laser, this laser beam directly gets into said integrated electro-optic modulator (3) through optical fiber (2), and this radio-frequency signal generator produces radiofrequency signal electrooptic modulator (3) is realized modulation.
5. device according to claim 4; It is characterized in that; Said radio-frequency signal generator comprises main shaking (4), and said radiofrequency signal is through this master (4) generation of shaking, this master shake (4) comprise controller (15), crystal oscillator (12), fractional frequency-division phase-locked loop (13); Low noise amplifier (16) and BPF. (17); Said controller (15) control fractional frequency-division phase-locked loop (13) produces radiofrequency signal, and this signal is amplified by low noise amplifier (16), and by being loaded on the said integrated electro-optic modulator (3) after BPF. (17) filtering.
6. device according to claim 5 is characterized in that, this controller (15) is controlled the frequency conversion time of said local oscillator (20) simultaneously, makes this master shake (20) and local oscillator (4) synchronous frequency conversion.
7. device according to claim 6 is characterized in that, being loaded into the last radiofrequency signal of said integrated electro-optic modulator (3) is three, and frequency is respectively 1.485GHz, 1.49925GHz, 1.5GHz.
8. device according to claim 1 is characterized in that, light path and outer light path in said inside and outside light path module is divided into through an optical fiber splitter (5), the light signal of interior light path directly from fiber optic conduction to said photodetection and signal processing module; Said outer light path comprises collimation lens set (6), is arranged on the catoptron (7) and the receiving objective group (8) at object under test place; Be somebody's turn to do the along of the optical signals fiber optic conduction of outer light path to collimation lens set (6); Toward mirror behind collimation (7); Get back to receiving objective group (8) after the reflection, send into said photodetection and signal processing module after the light signal focusing of this receiving objective group (8) with outer light path.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205227386U CN202351429U (en) | 2011-12-14 | 2011-12-14 | Laser phase method distance measuring device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205227386U CN202351429U (en) | 2011-12-14 | 2011-12-14 | Laser phase method distance measuring device |
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| CN202351429U true CN202351429U (en) | 2012-07-25 |
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| CN2011205227386U Withdrawn - After Issue CN202351429U (en) | 2011-12-14 | 2011-12-14 | Laser phase method distance measuring device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106813691A (en) * | 2015-11-27 | 2017-06-09 | 长城汽车股份有限公司 | Gear detection device and vehicle |
| CN110596718A (en) * | 2019-09-20 | 2019-12-20 | 梧州学院 | Phase distance measuring device and method based on laser heterodyne detection |
| CN111527417A (en) * | 2018-06-11 | 2020-08-11 | 深圳市镭神智能系统有限公司 | Light emitting module, light emitting unit, optical signal detection module, optical system, and laser radar system |
-
2011
- 2011-12-14 CN CN2011205227386U patent/CN202351429U/en not_active Withdrawn - After Issue
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106813691A (en) * | 2015-11-27 | 2017-06-09 | 长城汽车股份有限公司 | Gear detection device and vehicle |
| CN111527417A (en) * | 2018-06-11 | 2020-08-11 | 深圳市镭神智能系统有限公司 | Light emitting module, light emitting unit, optical signal detection module, optical system, and laser radar system |
| CN111527417B (en) * | 2018-06-11 | 2023-03-21 | 深圳市镭神智能系统有限公司 | Light emitting module, light emitting unit, optical signal detection module, optical system, and laser radar system |
| CN110596718A (en) * | 2019-09-20 | 2019-12-20 | 梧州学院 | Phase distance measuring device and method based on laser heterodyne detection |
| CN110596718B (en) * | 2019-09-20 | 2023-03-10 | 梧州学院 | Phase distance measuring device and method based on laser heterodyne detection |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20120725 Effective date of abandoning: 20130131 |
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| C20 | Patent right or utility model deemed to be abandoned or is abandoned |