CN113671521B - Coarse and fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and method - Google Patents
Coarse and fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and method Download PDFInfo
- Publication number
- CN113671521B CN113671521B CN202110925287.9A CN202110925287A CN113671521B CN 113671521 B CN113671521 B CN 113671521B CN 202110925287 A CN202110925287 A CN 202110925287A CN 113671521 B CN113671521 B CN 113671521B
- Authority
- CN
- China
- Prior art keywords
- measuring
- frequency
- laser
- phase
- light
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000005259 measurement Methods 0.000 claims abstract description 99
- 230000003287 optical effect Effects 0.000 claims abstract description 53
- 238000012545 processing Methods 0.000 claims abstract description 39
- 239000013307 optical fiber Substances 0.000 claims description 63
- 239000013078 crystal Substances 0.000 claims description 30
- 238000001914 filtration Methods 0.000 claims description 26
- 230000015572 biosynthetic process Effects 0.000 claims description 7
- 230000008859 change Effects 0.000 claims description 6
- 238000003786 synthesis reaction Methods 0.000 claims description 3
- 238000001514 detection method Methods 0.000 abstract description 23
- 230000002194 synthesizing effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 8
- 239000000835 fiber Substances 0.000 description 5
- 238000011160 research Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000003199 nucleic acid amplification method Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000005305 interferometry Methods 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003032 molecular docking Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000013341 scale-up Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/32—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
- G01S17/36—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated with phase comparison between the received signal and the contemporaneously transmitted signal
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
The invention relates to a phase laser ranging device and a ranging method for modulating and demodulating a coarse and fine measuring ruler difference frequency. The distance measuring device comprises a multi-frequency generation module, a laser modulation module, a measuring light path and an optical signal receiving and processing module; the ranging method starts a laser and a multi-frequency generation module; the laser is modulated to generate a precision measuring ruler c/v 1 C/v of secondary rough measuring rule 2 And a rough scale c/f in which the passing frequency is v 3 And v 3 Performing difference frequency modulation on the +f signal to generate a rough measuring scale c/f; dividing laser into reference light and measuring distance; the frequency of the precision measuring ruler is v 1 ‑f 1 Is demodulated and detected by a difference frequency signal f 1 Obtaining a precise measurement result, and detecting a secondary rough measurement ruler c/v 2 And rough measuring the scale c/f, obtaining the phase, and synthesizing phase difference data to obtain the measured distance. The invention breaks the limit of the coherence length of the laser interference, the bandwidth of the detection device and the modulation bandwidth, and can realize the accurate measurement of sub-millimeter or even micron in the measurement range requirement of hundreds of thousands of kilometers in the future.
Description
Technical Field
The invention relates to the technical field of absolute distance laser measurement, in particular to a phase laser ranging device and a method for modulating and demodulating a difference frequency of a coarse and fine measuring ruler.
Background
The laser ranging technology is widely applied to the fields of large equipment manufacture, spacecraft deep space navigation, rendezvous and docking, distributed formation satellites and the like by virtue of the advantages of high measurement precision, strong anti-interference capability, high space-time and vertical resolution and the like, and becomes an indispensable key technology in aerospace, major scientific devices and national economy development research. With the development of scientific technology, particularly the rapid progress of aerospace technology, higher performance requirements are put forward on the measurement range, measurement precision and stability of the measurement technology. In recent years, aiming at space physical detection research tasks, cooperative detection of complex physical processes in space by using small formation satellites becomes a research hotspot, such as GRACE-FO satellites of NASA in the United states, NMP ST-5 program, proba-3 satellites of European space, gemini satellites of Germany and the like, the space between the small formation satellites is from hundreds of meters to tens of kilometers, and the measurement precision of the distance reaches millimeter, submillimeter or even tens of micrometers. In the space gravitational wave detection research, the maximum arm length difference caused by the inter-satellite orbit dissociation reaches 30 ten thousand kilometers, and the absolute distance measurement precision of the arm length needs to reach 30cm in order to accurately capture gravitational wave signals. The processing and the integral assembly of large-scale components also put forward higher requirements on the distance measurement technology, taking a large-scale and ultra-large-scale single radio telescope as an example, in order to ensure the detection sensitivity and imaging precision of celestial bodies and interstellar molecules, the caliber of a reflecting surface ranging from hundreds of meters to thousands of meters is measured in real time and is integrally controlled, and the measuring precision of each reflecting surface is better than that of a few millimeters or hundreds of micrometers. Therefore, along with the increase of the space exploration range and the improvement of the detection precision requirement, the distance measurement technology is urgently required to simultaneously consider the ultra-long acting distance, the precision measurement accuracy and the high real-time performance in the future, and the sub-millimeter and even micrometer-level precision measurement of the fast moving target is realized in the range of hundreds of meters to hundreds of thousands of kilometers.
However, the ultra-precise measurement methods such as laser interference ranging, and ultra-long distance measurement methods such as differential GPS ranging, pseudo-random code modulation ranging, pulse laser ranging, visible light vision measurement technology, electro-optical modulation optical frequency comb absolute ranging, etc. currently adopted limit further improvement of the performance in principle or technology. For example, patent [ remote laser ranging system based on high-speed pseudo-random code modulation and photon counting, publication No.: the pseudo-random code modulation ranging method proposed by CN102928832A is similar to the pulse laser ranging method, is a pulse time-based measuring method, is limited by principle errors and device noise, and has the centimeter-level measuring precision approaching the technical limit. Patent [ sine phase modulation interference absolute distance measuring device and method based on femtosecond optical frequency comb, publication number: the optical frequency comb absolute ranging method proposed in CN108120378A is high in measurement accuracy, but is limited by coherence length, and is difficult to be used for measuring distances from hundreds of kilometers to hundreds of thousands of kilometers.
Patent [ large-range high-precision rapid laser ranging method and device with multi-frequency synchronous modulation, publication number: the multi-wavelength modulation phase laser ranging method and device proposed by CN1825138A are used for measuring the absolute distance between the modulation light wave emitted by the measuring end and the modulation light wave reflected by the measured object by using the phase difference between the modulation light wave and the modulation light wave. The method adopts a modulation method to generate a plurality of measuring rule wavelengths from coarse to fine for step-by-step measurement, optimizes step by step, uses a longer measuring rule for meeting the measurement range, uses a shorter measuring rule for realizing the measurement precision, and uses the rest measuring rules as transition measuring rules for connecting the coarse measuring rule and the fine measuring rule. Aiming at the distance measurement requirement of realizing micron-scale precision in a measuring range of hundreds of kilometers, the wavelength of a rough measuring ruler is larger than 200km, the corresponding frequency of the rough measuring ruler is lower than 1.5KHz, the measuring precision of 1 mu m is realized under the condition that the phase discrimination precision is 0.08 DEG, the wavelength of a required synthesized precise measuring ruler is 9mm, the corresponding frequency of the measuring ruler is 33.3GHz, and therefore, the modulation bandwidth of laser is at least covered with 1.5KHz to 33.3GHz. The current modulation method in this patent cannot achieve linear modulation bandwidths as high as tens to tens of GHz. The measurement range and measurement accuracy cannot meet the background application requirements.
Patent [ a laser phase method range unit, publication No.: CN202351429U adopts an electro-optical modulator to generate a measuring scale signal with a frequency above 1GHz, but the high bandwidth electro-optical modulator (above 10G) is affected by radio frequency line impedance, radio frequency jolle effect, etc., so that the physical properties of the electrode and the waveguide are changed, the low frequency modulation effect is poor, and the high bandwidth electro-optical modulator cannot be used for modulating the low frequency signal below 1MHz at the same time under the condition of ensuring the precision. Therefore, the modulation mode used today cannot meet the ultra-wide modulation range from tens of Hz to tens of GHz, which results in limitation of the multi-frequency/wavelength modulation phase laser ranging method in performing micron-level high-precision measurement within the ultra-long distance range, and further research on a high-bandwidth laser modulation method, namely a measuring rule generation mode, is required, especially, the non-ideal characteristic of low-frequency signal modulation is overcome, and the measurement range is expanded.
Secondly, the phase type laser ranging technology requires a photoelectric detection device to convert a coarse measuring ruler and a fine measuring ruler into electric signals for subsequent signal processing and phase discrimination, but the existing photoelectric detection device has poor detection effect and even can not directly detect the signals of the measuring ruler up to tens of GHz and even hundreds of GHz. Patent [ superheterodyne and heterodyne combined anti-optical aliasing laser ranging device and method, publication number: CN104049248A adopts a photoelectric detection method combining heterodyne and superheterodyne, and obtains a precise phase result by detecting the superheterodyne signal, thereby avoiding direct detection of signals of a precise measuring scale up to tens to hundreds of GHz. However, since the optical path lengths of the measurement light and the reference light are different, when the optical path length difference thereof is larger than the coherence length, the interference signal-to-noise ratio is lowered, and it is difficult to perform phase extraction. Therefore, the method is limited by the coherence length, and the measurement range is limited to the order of thousands of meters and is difficult to further improve while ensuring high-precision measurement.
In summary, the limitation of the laser modulation bandwidth, the detection bandwidth and the interference coherence length is broken, the measurement accuracy is improved, and the measurement range of the multi-wavelength modulation phase laser ranging technology is expanded, so that the laser ranging method needs to be further improved, and the accurate measurement of sub-millimeter or even micrometer level is achieved in the future measurement range requirement of hundreds of thousands of meters.
Disclosure of Invention
The invention breaks through the limitation of interference coherence length, detection bandwidth and modulation bandwidth in laser ranging, further improves the measuring range and precision of a multi-wavelength modulation interferometry method, realizes the accurate measurement reaching the sub-millimeter or even micron level in the measuring range requirement of hundreds of thousands of meters in the future, can meet the requirements of the fields of large-scale equipment manufacture, spacecraft deep space navigation, intersection butt joint, distributed formation satellites and the like, and provides a coarse-fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and a ranging method, which provide the following technical scheme:
a phase laser ranging device for modulating and demodulating a difference frequency of a coarse and fine measuring ruler, the device comprising: the system comprises a multi-frequency generation module, a laser modulation module, a measuring light path and an optical signal receiving and processing module, wherein the multi-frequency generation module generates three paths of outputs, two paths of outputs are input to the laser modulation module to modulate laser, and the other path of outputs are input to the optical signal processing and receiving module; the output light of the laser modulation module is input to a measuring light path, and two paths of output light of the measuring light path are respectively measuring light and reference light, and are input to an optical signal receiving and processing module for phase measurement.
Preferably, the multi-frequency generating module comprises a first crystal oscillator, a second crystal oscillator, a third crystal oscillator, a first phase-locking frequency doubling circuit, a second phase-locking frequency doubling circuit, a third phase-locking frequency doubling circuit, a fourth phase-locking frequency doubling circuit, a first to fifth amplifying circuit, a first power synthesizer and a second power synthesizer;
the output end of the first crystal oscillator is connected to the input end of the first phase-locked frequency doubling circuit and passes through the first amplifying circuit; the output signal of the first crystal oscillator is connected to the input end of the second phase-locked frequency doubling circuit, and passes through the second amplifying circuit, the output end of the second crystal oscillator is connected to the input end of the third amplifying circuit, and the output signal of the third crystal oscillator is connected to the input end of the third phase-locked frequency doubling circuit, and passes through the fourth amplifying circuit; the output signal of the third crystal oscillator is connected to the input end of the fourth phase-locked frequency doubling circuit and passes through the fifth amplifying circuit; the output end of the first amplifying circuit and the output end of the fifth amplifying circuit are respectively input into two input ends of the first power synthesizer, the output end of the first power synthesizer is connected to the input end of the first electro-optical modulator to serve as a driving signal, the output end of the second power synthesizer is connected to the input end of the second electro-optical modulator to serve as a driving signal, and the output end of the second amplifying circuit is connected to the input ends of the third electro-optical modulator and the fourth electro-optical modulator to serve as driving signals.
Preferably, the laser modulation module comprises a laser, a first electro-optical modulator, a second electro-optical modulator, a first double-path light splitting optical fiber and a second double-path light splitting optical fiber; the output of the laser is connected to a first two-way branching optical fiber and is divided into two ways, one way output end of the first two-way branching optical fiber is connected to the input end of the first electro-optical modulator, the other way output end of the first electro-optical modulator is connected to the input end of the second electro-optical modulator, the output ends of the first electro-optical modulator and the second electro-optical modulator are respectively connected to the two input ends of the second two-way branching optical fiber, and the output end of the second two-way branching optical fiber is connected to the input end of the measuring light path.
Preferably, the measuring light path comprises a first collimator, a second collimator, a third collimator, a spectroscope, a beam expander group and a measuring pyramid; the output end of the second two-way branching optical fiber is connected to the input end of the first collimator, the output end of the first collimator is connected to the spectroscope, one output of the spectroscope is used as reference light to be connected to the input end of the second collimator, the output end of the second collimator is connected to one input end of the optical signal receiving and processing module, the other output of the spectroscope is connected to the input end of the beam expanding lens group, the output end of the beam expanding lens group is connected to the input end of the measuring pyramid, the output end of the measuring pyramid is connected to the input end of the spectroscope through the beam expanding lens group, the output end of the spectroscope is connected to the input end of the third collimator to be used as measuring light, and the output end of the third collimator is connected to the other input end of the optical signal receiving and processing module.
Preferably, the optical signal receiving and processing module comprises a third two-way beam splitting optical fiber, a fourth two-way beam splitting optical fiber, a third electro-optical modulator, a fourth electro-optical modulator, a first to fourth photoelectric detector, a sixth to ninth amplifying circuit, a first to fourth filter circuit and a high-precision phase measuring board card; one output end of the measuring light path is used as reference light, is connected with the input end of the third two-way light splitting optical fiber and is divided into two paths, one output end of the third two-way light splitting optical fiber is connected to the input end of the third electro-optical modulator, the input end of the third electro-optical modulator is connected to the input end of the first photoelectric detector, the output end of the first photoelectric detector, the sixth amplifying circuit and the first filtering circuit are sequentially connected, the output end of the first filtering circuit is connected to the high-precision phase measuring board card, and the other output end of the third two-way light splitting optical fiber is connected to the input end of the second photoelectric detector, and sequentially passes through the seventh amplifying circuit and the second filtering circuit and is connected to the high-precision phase measuring board card;
the other output end of the measuring light path is used as measuring light, is connected with the input end of the fourth two-way branching optical fiber and is divided into two paths, one output end of the fourth two-way branching optical fiber is connected to the input end of the fourth electro-optical modulator, the output end of the fourth electro-optical modulator, the third photoelectric detector, the eighth amplifying circuit and the third filtering circuit are sequentially connected, and the output end of the third filtering circuit is connected to the high-precision phase measuring board card; the other output end of the fourth two-way branching optical fiber is connected to the input end of the fourth photoelectric detector and is connected to the high-precision phase measuring board card through the ninth amplifying circuit and the fourth filtering circuit in sequence.
A phase laser ranging method for modulating and demodulating a coarse and fine measuring ruler difference frequency comprises the following steps:
step 1: starting the multi-frequency generation module and the laser, wherein the output frequency is v 1 、v 1 -f 1 、v 2 、v 3 And v 3 The output laser is divided into two paths of laser by a first two-path beam splitting optical fiber, wherein one path of laser is input into a first electro-optical modulator at the frequency v 1 And v 3 The intensity modulation is carried out under the driving of sine wave of the second path of laser is input to a second electro-optical modulator, and the frequency is v 2 And v 3 Intensity modulation is carried out under the driving of sine waves of +f, and two paths of modulated output laser are synthesized into one beam of laser through a two-way beam splitting optical fiber;
step 2: the laser generated in the step 1 is incident into a spectroscope through a first collimator and is divided into two laser beams, one laser beam is used as reference light and is input into an optical signal receiving and processing module through a second collimator, and the other laser beam is used as measuring light and is emitted to a measuring pyramid prism through a beam expanding lens group;
step 3: moving the measurement pyramid prism to a target end, and after the measurement light is reflected by the pyramid prism, entering the spectroscope through the beam expanding lens group again, wherein laser output by the spectroscope is measurement light carrying distance information and is input to the optical signal receiving and processing module through the third collimator;
step 4: the reference light input into the optical signal receiving and processing module according to the step 2 is divided into two laser beams by a three-way and two-way beam splitting optical fiber, one of the two laser beams enters a three-way electro-optical modulator at the frequency v 1 -f 1 Intensity modulation is carried out under the driving of sine wave of reference light, and the light intensity change frequency in the reference light is v 1 Precision measuring rule of (2)After modulation, generating a difference frequency signal f 1 With accurate measuring rule phase information, the high-frequency signal is amplified and filtered by a first photoelectric detector, a sixth amplifying circuit and a first filtering circuit in sequence, and only the output frequency is f 1 The other beam of the three-path light splitting optical fiber is filtered to obtain signals with additional frequencies after passing through a second photoelectric detector, a seventh amplifying circuit and a second filtering circuit, and the signals are respectively output with the frequency v 2 And f;
step 5: the measuring light input to the optical signal receiving and processing module according to the step 3 is divided into two beams by a four-way and two-way beam splitting optical fiber, wherein one beam enters a four-way electro-optical modulator at the frequency v 1 -f 1 Intensity modulation is carried out under the driving of sine wave of (2), and the change frequency of the light intensity in the measuring light is v 1 After modulation, the precision measuring ruler of (2) generates a difference frequency signal f 1 With accurate measuring rule distance measuring phase information, the high-frequency signals are amplified and filtered by a third photoelectric detector, an eighth amplifying circuit and a third filtering circuit in sequence, and only the output frequency is f 1 The other beam of the four-path light splitting optical fiber outputs signals with additional frequencies after passing through a four-photoelectric detector, a nine-amplifying circuit and a four-filtering circuit, and outputs signals with the frequency v 2 And f;
step 6, the high-precision phase measurement board card respectively corresponds to the frequency f 1 、v 2 And f, measuring the phase difference between the reference signal and the measurement signal, the phase difference being respectivelyAnd->The data synthesis unit of the high-precision phase measurement board card synthesizes the three phase difference values to generate a distance value, the frequency of the rough measurement ruler is f, the wavelength is lambda, and the distance measurement value of the rough measurement ruler is +.>Frequency v 2 The signal of (2) is a secondary rough measuring scale and waveLambda of length 2 The distance measurement of the secondary rough ruler is represented by the following formula:
wherein the floor () function is a rounding function with a frequency v 1 The signal of (2) is a precision measuring rule, and the wavelength is lambda 1 ；
The measured distance is represented by the following formula:
preferably, the reference light and the measurement return light are subjected to secondary intensity modulation to realize difference frequency demodulation, and the frequency v is utilized 1 -f 1 The sine signal pair of (2) measures the accurate measuring scale signal in the return lightPerforming a second intensity modulation in whichWhen located at the linear modulation operating point, the modulated output optical signal is represented by:
the difference frequency signal is generated by the following expression:
the phase contains precisely measured phase information, and a detector is used for detecting a difference frequency signal f with lower frequency 1 And carrying out phase discrimination to obtain a precise measurement result.
Preferably, the coarse measuring scale is generated by differential frequency modulation of double high-frequency signals, and the coarse measuring scale is respectively modulated by electric light in the laser modulation moduleThe laser is subjected to high-frequency v by the laser 3 And v 3 Light intensity modulation of +f, detecting a difference frequency signal with frequency f in the measuring light and the reference light as a rough measuring scale in the light signal receiving and processing module, and expressing the frequency v at the photoelectric detector by the following formula 3 And v 3 Measurement optical signal of +f:
the light intensity signal detected by the photodetector at frequency f is represented by:
and the phase is the rough measurement distance measurement result as the rough measurement ruler signal.
Preferably, the frequency generated by the multi-frequency generation module is v 1 And v 1 -f 1 The signals of the first crystal oscillator come from the same signal source.
The invention has the following beneficial effects:
in the high-precision ranging system, the ranging result of the precision measuring ruler determines the precision which can be achieved by the ranging system, the higher the frequency of the precision measuring ruler is, the higher the ranging precision is, but the limitation of the bandwidth of the existing detecting device is caused when the optical signal receiving and the phase measuring are carried out, and the detection or the poor detection effect of the precision measuring ruler signal of tens of GHz is difficult. The detection frequency value can be reduced by using a common heterodyne or superheterodyne photoelectric detection method, however, when the optical path difference is larger than the coherence length, the interference signal-to-noise ratio is reduced, the phase extraction is difficult to carry out, and the improvement of the accuracy of a ranging system is further limited.
The invention utilizes the electro-optical intensity modulator to carry out secondary modulation on the precision measuring ruler signal (the frequency is v 1) in the reference light and the measuring light, and the frequency is v 1 -f 1 As a modulating signal, a frequency f is generated when the electro-optic modulator operates in a linear operating region 1 The difference frequency of the accurate measurement ruler signal is demodulated by the aid of the difference frequency signal of the accurate measurement ruler signal, and the phase of the difference frequency signal comprises phase information measured by the accurate measurement ruler. The frequency is f after demodulation by detecting the measurement signal and the reference signal 1 And phase measurement is carried out, and the measured value is the measured result of the precision measuring ruler. In a high-precision ranging system, the device and the method are utilized to carry out difference frequency demodulation on a precision measuring ruler, and the difference frequency signal with lower frequency (frequency is f 1 ) The distance measurement information of the precision measurement ruler is obtained, the direct detection of the optical signal of the precision measurement ruler is avoided, the problem that the high-frequency optical signal is difficult to detect or the detection effect is poor is solved, the limitation of the bandwidth of a detection device and the coherence length of laser on the distance measurement precision is broken, and the precision of a submillimeter or even tens of micrometers distance measurement system can be realized. This is one of the innovative points of the present invention to distinguish existing devices.
In the high-precision large-range ranging system, the ranging result of the rough measuring ruler determines the ranging range of the ranging system, the lower the rough measuring ruler frequency is, the larger the ranging range is, but because of radio frequency line impedance, radio frequency jolle effect and the like, the high-bandwidth electro-optical modulator cannot be used for low-frequency signal modulation (lower than 1 MHz), so that the modulation of the rough measuring ruler and the fine measuring ruler cannot be synchronously generated in the same modulation device while the ranging precision is ensured, and the expansion of the ranging range is influenced by the modulation bandwidth.
The invention adopts the electro-optical modulator to respectively carry out double high frequency (v) 3 And v 3 +f) difference frequency modulation; with frequency v 3 And v 3 And (3) ranging the signal of +f, wherein the difference frequency signal f in the detection measurement light and the reference light is used as a rough measurement ruler signal, and the phase of the rough measurement ruler signal is the rough measurement ruler ranging result. In a ranging system with high precision and large range, the device and the method are utilized to generate a rough measuring ruler through difference frequency modulation, avoid using a high bandwidth modulator for low frequency modulation at the same time, andand the range information of the rough measuring ruler can be obtained by detecting the difference frequency signal of the two high frequency signals, the limit of the modulation bandwidth on the extended range is broken, and the range can reach hundreds of meters to hundreds of thousands of meters. This is the second point of innovation in the present invention to distinguish existing devices.
Drawings
FIG. 1 is a schematic view of the overall structure of a laser ranging device according to the present invention;
FIG. 2 is a schematic diagram of a multi-frequency generation module;
FIG. 3 is a schematic diagram of a laser modulation module;
FIG. 4 is a schematic diagram of the structure of a measuring light path;
fig. 5 is a schematic structural diagram of an optical signal receiving and processing module.
The photoelectric signal receiving and processing device comprises a multi-frequency generating module 1, a laser modulating module 2, a measuring light path 3, a light signal receiving and processing module 4, a first crystal oscillator 5, a second crystal oscillator 6, a third crystal oscillator 7, a first phase-locked frequency doubling circuit 8, a second phase-locked frequency doubling circuit 9, a third phase-locked frequency doubling circuit 10, a fourth phase-locked frequency doubling circuit 11, a first amplifying circuit 12, a second amplifying circuit 13, a third amplifying circuit 14, a fourth amplifying circuit 15, a fifth amplifying circuit 16, a first power synthesizer 17, a second power synthesizer 18, a laser 19, a first two-way spectrooptical fiber 20, a first electro-optical modulator 21, a second electro-optical modulator 22, a second two-way spectrooptical fiber 23, a first collimator 24, a second collimator 25, a third collimator 26, a spectroscope 27, a beam expander group 28, a measuring two-way spectroscope 29, a third spectroscope 30, a fourth two-way spectrooptical fiber 31, a fourth two-way spectrooptical fiber 32, a third power modulator 33, a fourth detector 34, a fourth detector 36, a fourth detector circuit 37, a fourth detector circuit 45, a fourth filter circuit 44, a fourth filter circuit 45, a fourth filter circuit 37, a fourth filter circuit 45, a fourth filter circuit, and the like.
Detailed Description
The present invention will be described in detail with reference to specific examples.
First embodiment:
according to the figures 1-5, referring to the figures 1-5, the phase laser ranging device for the difference frequency modulation and demodulation of the rough and fine measuring ruler comprises a multi-frequency generating module 1, a laser modulating module 2, a measuring light path 3 and an optical signal receiving and processing module 4, wherein the multi-frequency generating module 1 generates three paths of outputs, two paths of outputs are input to the laser modulating module 2 to modulate laser, the other path of outputs are input to the optical signal processing and receiving module 4, the output light of the laser modulating module is input to the measuring light path 3, and the two paths of output light of the measuring light path 3 are respectively measuring light and reference light and are input to the optical signal receiving and processing module 4 to carry out phase measurement;
the multi-frequency generation module 1 comprises a first crystal oscillator 5, a second crystal oscillator 6, a third crystal oscillator 7, a first phase-locked frequency doubling circuit 8, a second phase-locked frequency doubling circuit 9, a third phase-locked frequency doubling circuit 10, a fourth phase-locked frequency doubling circuit 11, first to fifth amplifying circuits 12-16, a first power synthesizer 17 and a second power synthesizer 18, wherein the output end of the first crystal oscillator 5 is connected to the input end of the first phase-locked frequency doubling circuit 8, passes through the first amplifying circuit 12, the output signal of the first crystal oscillator 5 is connected to the input end of the second phase-locked frequency doubling circuit 9, passes through the second amplifying circuit 13, the output end of the second crystal oscillator 6 is connected to the input end of the third amplifying circuit 14, the output signal of the third crystal oscillator 7 is connected to the input end of the third phase-locked frequency doubling circuit 10, passes through the fourth amplifying circuit 15, and the output signal of the third crystal oscillator 7 is connected to the input end of the fourth phase-locked frequency doubling circuit 11, and passes through the fifth amplifying circuit 16; the output end of the first amplification circuit 12 and the output end of the fifth amplification circuit 16 are respectively input to two input ends of the first power combiner 17, the output end of the first power combiner 17 is connected to the input end of the first electro-optical modulator 21 as a driving signal, the output end of the second power combiner 18 is connected to the input end of the second electro-optical modulator 22 as a driving signal, and the output end of the second amplification circuit 13 is connected to the input ends of the third electro-optical modulator 32 and the fourth electro-optical modulator 33 as driving signals;
the laser modulation module 2 comprises a laser 19, a first electro-optical modulator 21, a second electro-optical modulator 22, a first two-way beam-splitting optical fiber 20 and a second two-way beam-splitting optical fiber 23. The output of the laser 19 is connected to a first two-way branching optical fiber 20 to be divided into two ways, one output end of the first two-way branching optical fiber 20 is connected to the input end of a first electro-optical modulator 21, the other output end of the first two-way branching optical fiber 20 is connected to the input end of a second electro-optical modulator 22, the output ends of the first electro-optical modulator 21 and the second electro-optical modulator 22 are respectively connected to the two input ends of a second two-way branching optical fiber 23, and the output end of the second two-way branching optical fiber 23 is connected to the input end of a measuring light path 3;
the measuring light path 3 comprises a first collimator 24, a second collimator 25, a third collimator 26, a spectroscope 27, a beam expander 28 and a measuring pyramid 29. The output end of the second two-way branching optical fiber 23 is connected to the input end of the first collimator 24, the output end of the first collimator 24 is connected to the spectroscope 27, one output of the spectroscope 27 is connected to the input end 25 of the second collimator as reference light, the output end of the second collimator 25 is connected to one input end of the optical signal receiving and processing module 4, the other output of the spectroscope 27 is connected to the input end of the beam expander group 28, the output end of the beam expander group 28 is connected to the input end of the measurement pyramid 29, the output end of the measurement pyramid 29 is connected to the input end of the spectroscope 27 through the beam expander group 28, the output end of the spectroscope 27 is connected to the input end of the third collimator 26 as measurement light, and the output end of the third collimator 26 is connected to the other input end of the optical signal receiving and processing module 4;
the optical signal receiving and processing module 4 comprises a third two-way light splitting optical fiber 30, a fourth two-way light splitting optical fiber 31, a third electro-optical modulator 32, a fourth electro-optical modulator 33, first to fourth photoelectric detectors 34 to 37, sixth to ninth amplifying circuits 38 to 41, first to fourth filter circuits 42 to 45 and a high-precision phase measuring board 46. One output end of the measuring light path 3 is used as reference light, is connected with the input end of the third two-way light splitting optical fiber 30 and is divided into two paths, one output end of the third two-way light splitting optical fiber 30 is connected to the input end of the third electro-optical modulator 32, the input end of the third electro-optical modulator 32 is connected to the input end of the first photoelectric detector 34, the output end of the first photoelectric detector 34, the sixth amplifying circuit 38 and the first filtering circuit 42 are sequentially connected, the output end of the first filtering circuit 42 is connected to a high-precision phase measuring board card, and the other output end of the third two-way light splitting optical fiber 30 is connected to the input end of the second photoelectric detector 35, sequentially passes through the seventh amplifying circuit 39 and the second filtering circuit 43 and is then connected to the high-precision phase measuring board card; the other output end of the measuring light path 3 is used as measuring light, is connected with the input end of the fourth two-way branching optical fiber 31 and is divided into two paths, one output end of the fourth two-way branching optical fiber 31 is connected to the input end of the fourth electro-optical modulator 33, the output end of the fourth electro-optical modulator 33, the third photoelectric detector 36, the eighth amplifying circuit 40 and the third filter circuit 44 are sequentially connected, and the output end of the third filter circuit 44 is connected to the high-precision phase measuring board card 46; the other output end of the fourth two-way branching optical fiber 31 is connected to the input end of the fourth photodetector 37, and is connected to the high-precision phase measurement board card 46 through the ninth amplifying circuit 41 and the fourth filtering circuit 45 in sequence.
The phase laser ranging method for the difference frequency modulation and demodulation of the coarse and fine measuring rule is applied to the phase laser ranging device for the difference frequency modulation and demodulation of the coarse and fine measuring rule, and is characterized by comprising the following steps of:
step 1, the multi-frequency generation module 1 and the laser 19 are started, and the output frequency is v 1 、v 1 -f 1 、v 2 、v 3 And v 3 The output laser is divided into two paths of laser by a first two-path beam splitting optical fiber 20, wherein one path of laser is input into a first electro-optical modulator 21 at the frequency v 1 And v 3 Is intensity modulated under the drive of sine wave, and the other laser is input into a second electro-optical modulator 22 at the frequency v 2 And v 3 Intensity modulation is carried out under the driving of sine wave of +f, and two paths of modulated output laser are synthesized into one beam of laser through a two-way beam splitting optical fiber 23;
step 2, a beam of laser generated in the step one is incident into a spectroscope 27 through a collimator No. 24 and is divided into two beams of laser, one beam of laser is used as reference light and is input into an optical signal receiving and processing module 4 through a collimator No. 25, and the other beam of laser is used as measuring light and is emitted to a measuring pyramid prism 29 through a beam expander group 28;
step 3, starting measurement, moving a measurement pyramid prism 29 to a target end, reflecting measurement light by the pyramid prism 29, then entering a spectroscope 27 again by a beam expander group 28, and inputting laser output by the spectroscope 27 into an optical signal receiving and processing module 4 through a third collimator 26, wherein the laser is measurement light carrying distance information;
step 4, the reference light input to the optical signal receiving and processing module 4 from step 2 is split into two beams of laser light by the three-beam two-way beam splitting optical fiber 30, one beam of laser light enters the three-beam electro-optical modulator 32 at the frequency v 1 -f 1 Intensity modulation is carried out under the driving of sine wave of reference light, and the light intensity change frequency in the reference light is v 1 After modulation, the precision measuring ruler of (2) generates a difference frequency signal f 1 With accurate measuring rule phase information, the high-frequency signals are amplified and filtered by the first photoelectric detector 34, the sixth amplifying circuit 38 and the first filter circuit 42 in sequence, so that only the frequency f is output 1 The other beam of the three-path light-splitting optical fiber 30 passes through the second photoelectric detector 35, the seventh amplifying circuit 39 and the second filtering circuit 43 to filter out signals with other frequencies, and outputs only the signals with the frequency v 2 And f;
step 5, the measuring light input to the optical signal receiving and processing module 4 from step 3 is split into two beams by the four-way optical splitting fiber 31, one beam enters the four-way electro-optical modulator 33 to be at the frequency v 1 -f 1 Intensity modulation is carried out under the driving of sine wave of (2), and the change frequency of the light intensity in the measuring light is v 1 After modulation, the precision measuring ruler of (2) generates a difference frequency signal f 1 With accurate measuring rule distance measuring phase information, the high-frequency signals are amplified and filtered by the third photoelectric detector 36, the eighth amplifying circuit 40 and the third filter circuit 44 in sequence, so that only the frequency f is output 1 The other beam of the four-path light-splitting optical fiber 31 outputs signals with other frequencies after passing through the four-photoelectric detector 37, the nine-amplification circuit 41 and the four-filtering circuit 45, and outputs signals with the frequency v 2 And f;
step 6, high-precision phase measurement board card 46 minThe other pair of frequencies is f 1 、v 2 And measuring the phase difference between the reference signal and the measurement signal, the phase difference being respectivelyAnd->The data synthesis unit of the high-precision phase measurement board card synthesizes the three phase difference values to generate a distance value, the frequency of the rough measurement ruler is f, the wavelength is lambda, and the distance measurement value of the rough measurement ruler is +.>Frequency v 2 The signal of (2) is a secondary rough measuring scale, and the wavelength is lambda 2 The distance measurement of the secondary rough measuring scale is +.>Frequency v 1 The signal of (2) is a precision measuring rule, and the wavelength is lambda 1 The measured distance is->
To solve the frequency v of the precision measuring ruler 1 The problems of over high difficulty in detection or poor detection effect are solved, and the difference frequency demodulation is realized by carrying out secondary intensity modulation on the reference light and the measurement return light. With frequency v 1 -f 1 The sine signal pair of (2) measures the accurate measuring scale signal in the return lightPerforming a second intensity modulation, wherein +.>When the linear modulation operating point is located, the modulated output optical signal is +.>Generating a difference frequency signal->The phase contains the precisely measured phase information, and a detector is used for detecting a difference frequency signal f with lower frequency 1 And carrying out phase discrimination to obtain a precise measurement result.
In order to solve the problem of poor low-frequency modulation effect of the electro-optical modulator, a coarse measuring scale is generated through differential frequency modulation of double high-frequency signals. The laser modulation module respectively carries out high-frequency v on the laser through the electro-optic modulator 3 And v 3 Light intensity modulation of +f, detecting difference frequency signal with frequency f in measuring light and reference light in light signal receiving and processing module as rough measuring scale, setting frequency v at photoelectric detector 3 And v 3 The measured optical signal of +f is:wherein-> The light intensity signal with the frequency f which can be detected by the photodetector is:>the phase of the rough measurement ruler signal is taken as a rough measurement distance measurement result.
The frequency generated by the multi-frequency generation module 1 is v 1 And v 1 -f 1 The signal of (2) comes from the same signal source-crystal oscillator 5, so the detected accurate measurement difference frequency signal f 1 Common mode noise is eliminated, and the frequency stability is good.
The above-mentioned only is a preferred embodiment of the device and method for measuring the phase laser of the differential frequency modulation and demodulation of the coarse and fine measuring scales, and the protection scope of the device and method for measuring the phase laser of the differential frequency modulation and demodulation of the coarse and fine measuring scales is not limited to the above-mentioned embodiments, and all technical solutions under the concept belong to the protection scope of the invention. It should be noted that modifications and variations can be made by those skilled in the art without departing from the principles of the present invention, which is also considered to be within the scope of the present invention.
Claims (5)
1. A phase laser ranging device for modulating and demodulating the difference frequency of a coarse and fine measuring ruler is characterized in that: the device comprises: the system comprises a multi-frequency generation module, a laser modulation module, a measuring light path and an optical signal receiving and processing module, wherein the multi-frequency generation module generates three paths of outputs, two paths of outputs are input to the laser modulation module to modulate laser, and the other path of outputs are input to the optical signal processing and receiving module; the output light of the laser modulation module is input into a measuring light path, two paths of output light of the measuring light path are respectively measuring light and reference light, and the two paths of output light of the measuring light path are respectively input into an optical signal receiving and processing module for phase measurement;
the multi-frequency generation module comprises a first crystal oscillator, a second crystal oscillator, a third crystal oscillator, a first phase-locking frequency multiplication circuit, a second phase-locking frequency multiplication circuit, a third phase-locking frequency multiplication circuit, a fourth phase-locking frequency multiplication circuit, a first to fifth amplifying circuit, a first power synthesizer and a second power synthesizer;
the output end of the first crystal oscillator is connected to the input end of the first phase-locked frequency doubling circuit and passes through the first amplifying circuit; the output signal of the first crystal oscillator is connected to the input end of the second phase-locked frequency doubling circuit, and passes through the second amplifying circuit, the output end of the second crystal oscillator is connected to the input end of the third amplifying circuit, and the output signal of the third crystal oscillator is connected to the input end of the third phase-locked frequency doubling circuit, and passes through the fourth amplifying circuit; the output signal of the third crystal oscillator is connected to the input end of the fourth phase-locked frequency doubling circuit and passes through the fifth amplifying circuit; the output end of the first amplifying circuit and the output end of the fifth amplifying circuit are respectively input to two input ends of the first power synthesizer, the output end of the first power synthesizer is connected to the first input end of the first electro-optical modulator to serve as driving signals, the output end of the third amplifying circuit and the output end of the fourth amplifying circuit are respectively input to two input ends of the second power synthesizer, the output end of the second power synthesizer is connected to the first input end of the second electro-optical modulator to serve as driving signals, and the output end of the second amplifying circuit is connected to the input ends of the third electro-optical modulator and the fourth electro-optical modulator to serve as driving signals;
the laser modulation module comprises a laser, a first electro-optical modulator, a second electro-optical modulator, a first double-path light splitting optical fiber and a second double-path light splitting optical fiber; the output of the laser is connected to a first two-way branching optical fiber and is divided into two ways, one output end of the first two-way branching optical fiber is connected to the second input end of the first electro-optical modulator, the other output end of the first electro-optical modulator and the output end of the second electro-optical modulator are respectively connected to the two input ends of the second two-way branching optical fiber, and the output end of the second two-way branching optical fiber is connected to the input end of the measuring light path;
the measuring light path comprises a first collimator, a second collimator, a third collimator, a spectroscope, a beam expander group and a measuring pyramid; the output end of the second two-way branching optical fiber is connected to the input end of the first collimator, the output end of the first collimator is connected to the first input end of the spectroscope, the first output of the spectroscope is used as reference light to be connected to the input end of the second collimator, the output end of the second collimator is connected to one input end of the optical signal receiving and processing module, the second output of the spectroscope is connected to the input end of the beam expanding lens group, the output end of the beam expanding lens group is connected to the input end of the measuring pyramid, the output end of the measuring pyramid is connected to the second input end of the spectroscope through the beam expanding lens group, the third output end of the spectroscope is connected to the optical path of the input end of the third collimator to serve as measuring light, and the output end of the third collimator is input to the other input end of the optical signal receiving and processing module;
the optical signal receiving and processing module comprises a third two-way light splitting optical fiber, a fourth two-way light splitting optical fiber, a third electro-optical modulator, a fourth electro-optical modulator, a first to fourth photoelectric detector, a sixth to ninth amplifying circuit, a first to fourth filter circuit and a high-precision phase measuring board card; the optical path of one output end of the measuring optical path is used as reference light, is connected with the input end of the third two-way light splitting optical fiber and is divided into two paths, one output end of the third two-way light splitting optical fiber is connected to the input end of the third electro-optical modulator, the output end of the third electro-optical modulator is connected to the input end of the first photoelectric detector, the output end of the first photoelectric detector, the sixth amplifying circuit and the first filtering circuit are sequentially connected, the output end of the first filtering circuit is connected to the high-precision phase measuring board card, and the other output end of the third two-way light splitting optical fiber is connected to the input end of the second photoelectric detector, and sequentially passes through the seventh amplifying circuit and the second filtering circuit and is then connected to the high-precision phase measuring board card;
the optical path of the other output end of the measuring optical path is used as measuring light, is connected with the input end of the fourth two-way branching optical fiber and is divided into two paths, one output end of the fourth two-way branching optical fiber is connected to the input end of the fourth electro-optical modulator, the output end of the fourth electro-optical modulator, the third photoelectric detector, the eighth amplifying circuit and the third filtering circuit are sequentially connected, and the output end of the third filtering circuit is connected to the high-precision phase measuring board card; the other output end of the fourth two-way branching optical fiber is connected to the input end of the fourth photoelectric detector and is connected to the high-precision phase measuring board card through the ninth amplifying circuit and the fourth filtering circuit in sequence.
2. A method for measuring distance by using phase laser with difference frequency modulation and demodulation of a coarse and fine measuring ruler, which is based on the phase laser distance measuring device with difference frequency modulation and demodulation of the coarse and fine measuring ruler, and is characterized in that: the method comprises the following steps:
step 1: starting the multi-frequency generation module and the laser, wherein the output frequency is v 1 、v 1 -f 1 、v 2 、v 3 And v 3 The output laser is divided into two paths of laser by a first two-path beam splitting optical fiber, wherein one path of laser is input into a first electro-optical modulator at the frequency v 1 And v 3 The intensity modulation is carried out under the driving of sine wave of the second path of laser is input to a second electro-optical modulator, and the frequency is v 2 And v 3 Intensity modulation is carried out under the driving of sine waves of +f, and two paths of modulated output laser are synthesized into one beam of laser through a two-way beam splitting optical fiber;
step 2: the laser generated in the step 1 is incident into a spectroscope through a first collimator and is divided into two laser beams, one laser beam is used as reference light and is input into an optical signal receiving and processing module through a second collimator, and the other laser beam is used as first measuring light and is emitted to a measuring pyramid prism through a beam expander group;
step 3: moving the measuring pyramid prism to a target end, wherein the first measuring light is reflected by the pyramid prism and then is incident to the spectroscope through the beam expanding lens group again, and the laser output by the spectroscope is second measuring light carrying distance information and is input to the optical signal receiving and processing module through the third collimator;
step 4: the reference light input into the optical signal receiving and processing module according to the step 2 is divided into two laser beams by a three-way and two-way beam splitting optical fiber, one of the two laser beams enters a three-way electro-optical modulator at the frequency v 1 -f 1 Intensity modulation is carried out under the driving of sine wave of reference light, and the light intensity change frequency in the reference light is v 1 After modulation, the precision measuring ruler of (2) generates a difference frequency signal f 1 With accurate measuring rule phase information, the high-frequency signal is amplified and filtered by a first photoelectric detector, a sixth amplifying circuit and a first filtering circuit in sequence, and only the output frequency is f 1 The other beam of the three-path light splitting optical fiber is filtered to obtain signals with additional frequencies after passing through a second photoelectric detector, a seventh amplifying circuit and a second filtering circuit, and the signals are respectively output with the frequency v 2 And f;
step 5: the second measuring light input to the optical signal receiving and processing module according to the step 3 is divided into two beams by a four-way double-path light splitting optical fiber, wherein one beam enters a four-way electro-optical modulator at the frequency v 1 -f 1 Intensity modulation is carried out under the driving of sine wave of the second measuring light, and the change frequency of the light intensity in the second measuring light is v 1 After modulation, the precision measuring ruler of (2) generates a difference frequency signal f 1 With accurate measuring rule distance measuring phase information, the high-frequency signals are amplified and filtered by a third photoelectric detector, an eighth amplifying circuit and a third filtering circuit in sequence, and only the output frequency is f 1 The other beam of the four-path light splitting optical fiber outputs signals with additional frequencies after passing through a four-photoelectric detector, a nine-amplifying circuit and a four-filtering circuit, and outputs signals with the frequency v 2 And f;
step 6, the high-precision phase measurement board card respectively corresponds to the frequency f 1 、v 2 And f, measuring the phase difference between the reference signal and the measurement signal, the phase difference being respectivelyAnd->The data synthesis unit of the high-precision phase measurement board card synthesizes the three phase difference values to generate a distance value, the frequency of the rough measurement ruler is f, the wavelength is lambda, and the distance measurement value of the rough measurement ruler is +.>
Frequency v 2 The signal of (2) is a secondary rough measuring scale, and the wavelength is lambda 2 The distance measurement of the secondary rough ruler is represented by the following formula:
wherein the floor () function is a rounding function with a frequency v 1 The signal of (2) is a precision measuring rule, and the wavelength is lambda 1 ；
The measured distance is represented by the following formula:
3. the method for measuring the distance of the phase laser of the coarse and fine measuring ruler by difference frequency modulation and demodulation according to claim 2, which is characterized in that: performing second intensity modulation on the reference light and the second measuring light to realize difference frequency demodulation, and using the frequency v 1 -f 1 The sine signal pair of (2) measures the accurate measuring scale signal in the return lightPerforming a second intensity modulation, wherein +.>
When located at the linear modulation operating point, the modulated output optical signal is represented by:
the difference frequency signal is generated by the following expression:
the phase contains precisely measured phase information, and a detector is used for detecting a difference frequency signal f with lower frequency 1 And carrying out phase discrimination to obtain a precise measurement result.
4. The method for measuring the distance of the phase laser of the coarse and fine measuring ruler by difference frequency modulation and demodulation according to claim 3, which is characterized in that:
coarse measuring scale is generated through difference frequency modulation of double high-frequency signals, and high-frequency v is carried out on laser in a laser modulation module through an electro-optical modulator respectively 3 And v 3 Light intensity modulation of +f, detecting a difference frequency signal with frequency f in the second measuring light and the reference light as a rough measuring scale in the light signal receiving and processing module, the frequency v at the photodetector is represented by the following formula 3 And v 3 Measurement optical signal of +f:
the light intensity signal detected by the photodetector at frequency f is represented by:
and the phase is the rough measurement distance measurement result as the rough measurement ruler signal.
5. The method for measuring the distance of the phase laser of the coarse and fine measuring ruler by difference frequency modulation and demodulation according to claim 4, which is characterized in that:
the frequency generated by the multi-frequency generation module is v 1 And v 1 -f 1 The signals of the first crystal oscillator come from the same signal source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110925287.9A CN113671521B (en) | 2021-08-12 | 2021-08-12 | Coarse and fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110925287.9A CN113671521B (en) | 2021-08-12 | 2021-08-12 | Coarse and fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113671521A CN113671521A (en) | 2021-11-19 |
| CN113671521B true CN113671521B (en) | 2024-03-26 |
Family
ID=78542497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110925287.9A Active CN113671521B (en) | 2021-08-12 | 2021-08-12 | Coarse and fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113671521B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101349757A (en) * | 2008-09-10 | 2009-01-21 | 哈尔滨工业大学 | Active collaboration type phase laser distance measuring method and apparatus |
| CN102419166A (en) * | 2011-08-17 | 2012-04-18 | 哈尔滨工业大学 | High-precision multi-frequency phase-synchronized laser distance measurement device and method |
| CN104035087A (en) * | 2014-06-14 | 2014-09-10 | 哈尔滨工业大学 | High-accuracy synchronous multi-measurement-ruler based semiconductor laser distance measurement device and method |
| CN104155643A (en) * | 2014-06-14 | 2014-11-19 | 哈尔滨工业大学 | High-precision synchronous mixed heterodyne-mode phase laser range finding device and method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110174058B (en) * | 2019-06-06 | 2020-06-23 | 浙江理工大学 | Dynamic offset frequency locking type sine frequency scanning interference absolute distance measuring device and method |
-
2021
- 2021-08-12 CN CN202110925287.9A patent/CN113671521B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101349757A (en) * | 2008-09-10 | 2009-01-21 | 哈尔滨工业大学 | Active collaboration type phase laser distance measuring method and apparatus |
| CN102419166A (en) * | 2011-08-17 | 2012-04-18 | 哈尔滨工业大学 | High-precision multi-frequency phase-synchronized laser distance measurement device and method |
| CN104035087A (en) * | 2014-06-14 | 2014-09-10 | 哈尔滨工业大学 | High-accuracy synchronous multi-measurement-ruler based semiconductor laser distance measurement device and method |
| CN104155643A (en) * | 2014-06-14 | 2014-11-19 | 哈尔滨工业大学 | High-precision synchronous mixed heterodyne-mode phase laser range finding device and method |
Non-Patent Citations (2)
| Title |
|---|
| 基于双频调制信号的相位法距离测量研究;范圆圆;中国优秀硕士学位论文全文数据库 信息科技辑;正文第11-18页 * |
| 基于同步可调谐测尺方法的相位式激光测距技术研究;杨宏杰;万方学位论文;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113671521A (en) | 2021-11-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110061778B (en) | Optical fiber microwave and optical frequency simultaneous transmission device and transmission method | |
| CN104459683B (en) | Multiple target displacement high-precision measuring method based on microwave radar and system | |
| Donati | Electro-optical instrumentation: sensing and measuring with lasers | |
| CN102305591B (en) | Multi-frequency synchronization phase laser ranging device and method based on dual-acousto-optic shift frequency | |
| CN111693988A (en) | Laser millimeter wave integrated distance and speed measuring radar method and device | |
| CN113687377B (en) | Cooperative phase laser ranging device based on coarse and fine measuring ruler difference frequency modulation and demodulation | |
| CN110412606B (en) | Device and method for simultaneously measuring distance and displacement based on heterodyne laser interferometer | |
| CN108332735B (en) | Resonance type fiber-optic gyroscope coherent demodulation system and method based on external beam interference | |
| CN110596718B (en) | Phase distance measuring device and method based on laser heterodyne detection | |
| CN102680981A (en) | Distance measurement method and device based on orthogonal locking of microwave photon signals | |
| CN101354248A (en) | High precision absolute distance measuring instrument of frequency scanning interference method | |
| CN113589309B (en) | Non-cooperative target space position detection method based on microwave photon technology | |
| CN110133679B (en) | Doppler velocity measurement system based on monolithic integrated dual-frequency laser | |
| CN113687378B (en) | Multi-frequency mixed heterodyne type laser absolute ranging system and ranging method based on single light source | |
| US11378401B2 (en) | Polarization-maintaining fully-reciprocal bi-directional optical carrier microwave resonance system and angular velocity measurement method thereof | |
| CN113671521B (en) | Coarse and fine measuring ruler difference frequency modulation and demodulation phase laser ranging device and method | |
| CN112797973A (en) | Device and method for improving stability of fiber-optic gyroscope | |
| CN104049248A (en) | Superheterodyne and heterodyne combined type optical-aliasing-resistance laser ranging device and method | |
| CN114696899B (en) | Distance measurement method based on multi-frequency heterodyne principle and light-loaded microwave interference | |
| CN106936498B (en) | A kind of signal analysis method based on ultra wide band phase noise measuring system | |
| CN112129229B (en) | Quasi-distributed displacement measuring device and method based on photoelectric oscillator | |
| CN113702908A (en) | High-precision three-dimensional sound source positioning scheme based on PDH demodulation technology | |
| CN104155642A (en) | Traceable synchronous measurement ruler-based mixed double-light source laser range finding device and method | |
| Jacobson et al. | Novel interferometer for the measurement of plasma density | |
| Shao et al. | Microwave-photonic dynamic frequency-swept interferometry for fast ranging |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |