CN112711031B - Improved quasi-blind area-free Doppler coherent laser radar wind speed measurement system and method - Google Patents
Improved quasi-blind area-free Doppler coherent laser radar wind speed measurement system and method Download PDFInfo
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- CN112711031B CN112711031B CN202011490655.3A CN202011490655A CN112711031B CN 112711031 B CN112711031 B CN 112711031B CN 202011490655 A CN202011490655 A CN 202011490655A CN 112711031 B CN112711031 B CN 112711031B
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- 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
- G01S17/50—Systems of measurement based on relative movement of target
- G01S17/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
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- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
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- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
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- Optical Radar Systems And Details Thereof (AREA)
Abstract
The application relates to the technical field of laser radars, in particular to an improved quasi-blind area-free Doppler coherent laser radar wind speed measurement system and method. The application has the advantages that: the application adjusts the included angle between the laser transmitting optical axis and the laser receiving optical axis, removes the influence of the intermediate frequency signal on the useful wind speed signal, thereby improving the signal-to-noise ratio and realizing the detection precision and the resolution capability of the weak wind field signal.
Description
The application discloses a system and a method for measuring the wind speed of a quasi-blind-zone-free Doppler dry-seeking laser radar, which are provided with application numbers of 201910608446.5.
Technical Field
The application relates to the technical field of laser radars, in particular to an improved system and method for measuring wind speed of a quasi-blind-zone-free Doppler coherent laser radar.
Background
The real-time atmospheric wind field information can provide atmospheric wind field data support for wind power generation site selection, climate monitoring and pollution transportation; meanwhile, the real-time wind direction shear also can influence the navigation stability of the aircraft, and the detection and early warning of the real-time wind field in the field of aviation are important for the take-off and landing of the civil aircraft. The prior art for obtaining the atmospheric wind field has more technical methods, such as measuring the atmospheric wind field by using a conventional meteorological sounding balloon, measuring the atmospheric wind field by using a microwave anemometer radar, measuring the atmospheric wind field by using a laser coherent radar and the like; various wind field measurement means are applied in different fields. The conventional sounding method is applied to the meteorological field more, and has the advantages that an atmospheric wind field is directly obtained according to the GPS position change of the sounding balloon, and the measurement method is direct, and the measurement height can reach twenty-thirty kilometers above ground; the disadvantage is that the period of measuring the wind field is long, and a group of wind profiles requires 1-2 hours. The microwave wind-finding radar is more in current application, has the advantages that microwaves can observe an atmospheric wind field all-weather without being interfered by cloud layers, and has the disadvantages that the transmitting/receiving antenna array of the microwave wind-finding radar is large in volume and a blind area in low altitude is published and reported about one hundred meters. For a laser coherent wind-finding radar, two systems of continuous laser and pulse laser coherent wind-finding exist at present, the continuous laser radar focuses on low-altitude wind field measurement, and the maximum measurement height is low; the pulse laser radar can measure a high-altitude wind field but has a large low-altitude blind area. The low-altitude blind area of the disclosed continuous laser coherent wind-finding radar is about tens of meters, and the blind area of the pulse laser radar, which is limited by the pulse width and is due to the reflection of the transmitting laser end face, is larger than that of the continuous laser radar, and is about hundreds of meters. Therefore, the laser coherent wind-finding radar with two systems does not solve the problem of low-altitude blind areas.
Disclosure of Invention
Aiming at the problems of large low-altitude blind area, low resolution and complex system existing in the laser coherent wind measurement technology, the application provides an improved system and a method for measuring the wind speed of a quasi-blind area-free Doppler coherent laser radar.
In order to achieve the above purpose, the present application adopts the following technical scheme:
the improved quasi-blind area-free Doppler coherent laser radar wind speed measurement system comprises a transmitting device and a receiving device, wherein an included angle alpha is formed between a laser transmitting optical axis transmitted to the atmosphere by the transmitting device and a laser receiving optical axis of the receiving device, and the included angle alpha is adjustable.
Preferably, the transmitting device comprises a transmitting optical fiber and a first beam expander which are sequentially arranged on a laser transmitting optical axis, the main vibration light passes through the first beam expander to be emitted out of the transmitting device after being transmitted by the transmitting optical fiber, and a transmitting moving assembly for driving the end face to move is further arranged at the output end face of the transmitting optical fiber;
the receiving device comprises a second beam expander and a receiving optical fiber which are sequentially arranged on a laser receiving optical axis, the receiving light passing through the second beam expander is input into the input end face of the receiving optical fiber, and a receiving moving assembly for adjusting the position of the end face is arranged at the input end face of the receiving optical fiber.
Preferably, the transmitting moving assembly comprises a first fixing piece for fixing the output end face of the transmitting optical fiber and a transmitting translation table, wherein the transmitting translation table is used for fixing the first fixing piece and driving the optical fiber end face on the first fixing piece to move in a set direction; similarly, the receiving moving assembly comprises a second fixing piece for fixing the input end face of the receiving optical fiber and a receiving translation table, wherein the receiving translation table is used for fixing the second fixing piece and driving the optical fiber end face on the second fixing piece to move in a set direction.
Preferably, the system further comprises a laser reflection unit, the laser reflection unit comprises an emission optical adjustment lens, a receiving optical adjustment lens and a blade prism, the emission optical adjustment lens reflects incident light emitted by the emission device to the upper edge position of one coating surface of the blade prism and then reflects the incident light to the atmosphere, and the receiving optical adjustment lens continues to reflect the received light to a second beam expander in the receiving device after the upper edge position of the other coating surface of the blade prism reflects the received light to the receiving optical adjustment lens.
Preferably, the angles of the transmitting optical adjusting lens and the receiving optical adjusting lens are adjustable.
Preferably, a diaphragm is arranged on the blade prism along the direction parallel to the laser receiving optical axis.
Preferably, the system further comprises a laser generating unit, wherein the laser generating unit comprises a laser, and laser emitted by the laser is pulse laser or continuous laser.
The method for using the improved quasi-blind area-free Doppler coherent laser radar wind speed measurement system, wherein the system further comprises a coupler, a photoelectric differential detector and a processing control unit, and the method comprises the following steps of:
s1, adjusting a transmitting device and a receiving device to enable a laser transmitting optical axis of the transmitting device and a laser receiving optical axis of the receiving device to be located on the same plane, wherein the plane is a plane A;
s2, determining displacement surfaces of the transmitting mobile assembly and the receiving mobile assembly, and ensuring that the displacement surfaces of the transmitting mobile assembly and the receiving mobile assembly are parallel to a plane A;
s3, the processing control unit controls the included angle between the moving direction of the transmitting moving assembly and the laser transmitting optical axis, and the position of the focusing focus of the transmitting laser is ensured to be always on the laser transmitting optical axis in the moving process of the transmitting moving assembly; meanwhile, the processing control unit ensures that echo signals at the focus of the emitted laser are always coupled into the receiving optical fiber at the focus of the receiving device by adjusting the position of the receiving mobile component;
s4, calibrating according to the theoretical relation between the included angle alpha between the laser emission optical axis and the laser receiving optical axis and the positions of the emission mobile assembly and the receiving mobile assembly in the moving process of the emission mobile assembly and the receiving mobile assembly, so as to obtain the included angle between the laser emission optical axis and the laser receiving optical axis according to the translation amount of the emission mobile assembly and the receiving mobile assembly, and further obtain the measuring height of the radar;
s5, after the echo signals with the designated height pass through the coupler and the local oscillation light beat frequency, the photoelectric differential detector converts the beat frequency signals which are the light signals into electric signals, and the electric signals are transmitted to the processing control unit for fast Fourier transformation, so that the radial wind speed of the current point is obtained.
Preferably, the system further comprises a laser reflection unit, and in step S1, the angles of the laser transmitting lens and the laser receiving lens in the laser reflection unit are required to be adjusted, so that the laser transmitting optical axis of the transmitting device and the laser receiving optical axis of the receiving device are located on the same plane; in step S3, when the included angle between the moving direction of the output end face of the transmitting optical fiber and the laser transmitting optical axis is changed, the transmitting optical adjusting lens is moved to realize that the transmitting light edge coincides with the upper edge of the blade prism; meanwhile, the receiving optical adjusting lens is moved, so that the included angle between the laser transmitting optical axis and the laser receiving optical axis is as small as possible on the premise that the transmitting device and the receiving device keep no light cutting.
The application has the advantages that:
(1) With the conventional coaxial structure, due to reflection of the end face and the mirror surface of the optical fiber, an intermediate frequency signal exists in the echo signal, and the intermediate frequency signal may drown an unused wind speed signal, so that a wind speed at a lower height cannot be detected during low-altitude measurement. The application adjusts the included angle between the laser transmitting optical axis and the laser receiving optical axis, removes the influence of the intermediate frequency signal on the useful wind speed signal, thereby improving the signal-to-noise ratio and realizing the detection precision and the resolution capability of the weak wind field signal. The wind profile measuring device can measure wind profiles with different heights by adjusting the included angle alpha.
(2) According to the application, the coplanar laser emission optical axis and the laser receiving optical axis and the parallel displacement surfaces in the emission moving assembly and the receiving moving assembly are realized, so that the brightest area near the optical axis of the echo signal is always kept at the center of the optical fiber end face of the receiving device when the emission moving assembly and the receiving moving assembly move, and the receiving efficiency of the radar is ensured. Specifically, the transmitting optical fiber and the receiving optical fiber in the application both use single-mode polarization maintaining optical fibers, the diameter of the fiber core is about ten micrometers, and the receiving view field is in micro radian magnitude, so that the coupling efficiency is improved.
(3) According to the application, the included angle between the laser emission optical axis and the laser receiving optical axis is obtained by calibrating the moving position of the emission moving assembly, and the radar measurement height is determined by the included angle, so that the laser emission optical axis and the laser receiving optical axis can be intersected at a few meters in low altitude by changing the position of the output end face of the emission optical fiber; the method realizes the quasi-blind zone-free measurement of the atmospheric wind field. In addition, the application can only detect echo signals in the crossing area of the two beams of light of the laser transmitting optical axis and the laser receiving optical axis, and the high resolution is related to the length of the crossing area only; the application has small actual light beam overlapping area and high measurement resolution.
(4) The wind-finding radar adopts air scattering light as a signal to measure a wind field, and the air scattering signal is very weak; according to the application, the knife-edge prism is adopted to transmit and receive laser, so that the included angle between the laser transmitting optical axis and the receiving laser optical axis is as small as possible under the determined transmitting/receiving caliber, the cross area at the measuring height can be obviously increased, the effective echo volume is increased, and the echo signal intensity is increased. The light shielding diaphragm is arranged at the top end of the blade prism, so that forward scattered light of the emitted laser is prevented from entering the receiving device, the emitted light path and the received light path are completely independent, the emitted light is prevented from interfering the receiving device, and the imaging signal-to-noise ratio is improved.
(5) The application is compatible with two systems of pulse laser and continuous laser; compared with the traditional pulse radar, when the pulse system is adopted, the receiving device only detects echo signals near the crossing position of the optical axis, the echo signals are not influenced by pulse width and are not interfered by emitted laser, and the radar can detect signals in ten meters in low altitude; and because the peak power of the pulse radar is high, the scheme can also measure the atmospheric wind field with the height range of thousands of meters.
(6) The processing control unit is used for completing detection of Doppler frequency shift signals caused by a wind field and obtaining radial wind speed of the laser emission direction, and meanwhile, controlling the emission device and the receiving device to realize measurement of wind speeds and wind directions at different heights.
Drawings
FIG. 1 is a schematic diagram of the structural design of the radar of the present application.
Fig. 2 is a schematic view of the coplanar laser transmitting optical axis and the laser receiving optical axis and the moving direction of the translation stage.
FIG. 3 shows the Doppler shift signal of the wind field for measuring the height of 8 meters in practice.
FIG. 4 shows a wind field Doppler shift signal measured with a continuous laser at 280 meters height in accordance with the present application.
FIG. 5 is a plot of visibility monitoring for the test period of the present application.
1-laser generating unit 11-laser 12-local oscillation light
2-laser emitting unit
21-first fixing piece 22-transmitting translation stage 23-first beam expander 24-transmitting optical fiber
3-laser reflection unit
31-transmitting optical adjusting lens 32-receiving optical adjusting lens 33-blade prism
4-laser receiving unit
41-second fixing piece 42-receiving translation stage 43-second beam expander 44-receiving optical fiber
5-coupler 6-photoelectric differential detector 7-processing control unit 8-diaphragm
9-laser emission optical axis 10-laser reception optical axis
Detailed Description
As shown in fig. 1, an improved quasi-blind area-free doppler coherent laser radar wind speed measurement system comprises a laser generating unit 1, a transmitting device 2, a laser reflecting unit 3, a receiving device 4, a coupler 5, a photoelectric differential detector 6 and a processing control unit 7.
The laser generating unit 1 comprises a laser 11, a beam splitter for splitting the laser emitted by the laser 11 into two beams, and an acousto-optic modulator arranged on the coaxial direction of one beam of laser, wherein a frequency shifter is integrated inside the laser 11 to enable a fixed frequency difference to exist between the local oscillation light 12 and the main laser 13. The output end of the acousto-optic modulator outputs main vibration light which is sent to the transmitting device (2), and the other beam is used as local vibration light. The frequency of the laser changes to generate fixed frequency shift after the laser passes through the acousto-optic modulator. The main vibration light is transmitted to the air through the transmitting device 2 and the laser reflecting unit 3 to measure Doppler shift caused by the air, the echo signal carrying the Doppler shift signal is sequentially transmitted to the coupler 5 through the laser reflecting unit 3 and the receiving device 4 to be input into the coupler 5 together with the local vibration light signal sent by the laser generating unit 1 to be coupled, the light signal at the output end of the coupler 5 is transmitted to the photoelectric differential detector 6, the photoelectric differential detector 6 converts the light signal into an electric signal and then transmits the electric signal to the processing control unit 7 to be processed, and then the air Doppler shift signal is detected to obtain the atmospheric wind speed.
The transmitting device 2 comprises a transmitting optical fiber 24 and a first beam expander 23 which are sequentially arranged on a laser transmitting optical axis 9, the main vibration light is transmitted through the transmitting optical fiber 24 and then passes through the first beam expander 23 to be emitted out of the transmitting device 2, and a transmitting moving assembly for driving the end face to move is further arranged at the output end face of the transmitting optical fiber 24. The launch moving assembly comprises a first fixing piece 21 for fixing the output end face of the launch optical fiber 24, and a launch translation stage 22, wherein the launch translation stage 22 is used for fixing the first fixing piece 21 and driving the optical fiber end face thereon to move in a set direction.
The receiving device 4 comprises a second beam expander 43 and a receiving optical fiber 44 which are sequentially arranged on the laser receiving optical axis 10, the receiving light passing through the second beam expander 43 is input into the input end face of the receiving optical fiber 44, and a receiving moving assembly for adjusting the position of the end face is arranged at the input end face of the receiving optical fiber 44. The receiving and moving assembly comprises a second fixing piece 41 for fixing the input end face of the receiving optical fiber 44, and a receiving translation table 42, wherein the receiving translation table 42 is used for fixing the second fixing piece 41 and driving the optical fiber end face thereon to move in a set direction.
The movement of the emission translation stage 22 enables the emission laser to be focused at different heights; and simultaneously, the position of the receiving translation stage 42 is adjusted to realize the echo signal at the focus of the emitted laser, and the receiving translation stage 42 moves so that the input end face of the receiving optical fiber 44 is always positioned at the focus of the receiving device.
In this embodiment, the structure of the transmitting device 2 and the receiving device are the same, i.e., mass production is possible, and the production cost is reduced.
The laser reflection unit 3 includes an emission optical adjustment lens 31, a receiving optical adjustment lens 32, and a blade prism 33, where the emission optical adjustment lens 31 reflects incident light emitted by the emission device 2 to an upper edge position of a coated surface of the blade prism 33 and then reflects the incident light to the atmosphere, and the receiving optical adjustment lens 32 continues to reflect the received light to a second beam expander 43 in the receiving device 4 after the upper edge position of another coated surface of the blade prism 33 reflects the received light to the receiving optical adjustment lens 32. The angles of the transmitting optical adjustment lens 31 and the receiving optical adjustment lens 32 are adjustable. The functions of the transmitting optical adjustment lens 31, the receiving optical adjustment lens 32, and the blade prism 33 in the optical lens group 3 are: the upper edge of the emission light beam is overlapped with the upper edge of the blade prism, the upper edge of the receiving light beam is overlapped with the upper edge of the blade prism, and the included angle between the emission optical axis 9 and the laser receiving optical axis 10 can be as small as possible through two overlapping operations, so that the overlapping area of the two light beams is increased, and the echo signal intensity is further increased. The blade prism 33 is provided with a diaphragm 8 in a direction parallel to the laser receiving optical axis 10. When the transmitting translation stage 22 moves, the direction of the transmitting light beam is changed, and the laser irradiated to the upper edge of the blade prism 33 is diffracted, so that part of the laser is directly incident into the receiving device 4; and the laser forward scattered light may also enter the receiving means 4. The signal intensity of the direct or forward scattered light of the emitting device 2 is much stronger than the backscattered signal intensity of the measuring altitude air. The diaphragm 8 closely connected with the upper edge of the blade prism 33 plays a role in avoiding interference of the transmitted beam signal with the received signal, and the transmitting device 2 and the receiving device 4 are completely independent.
The specific method for using the system is as follows:
s1, adjusting the emitting device 2 and the receiving device 4 to enable a laser emitting optical axis 9 of the emitting device 2 and a laser receiving optical axis 10 of the receiving device 4 to be located on the same plane, wherein the plane is a plane A;
s2, determining displacement surfaces of the transmitting mobile assembly and the receiving mobile assembly, and ensuring that the displacement surfaces of the transmitting mobile assembly and the receiving mobile assembly are parallel to a plane A;
s3, a processing control unit 7 controls the included angle between the moving direction of the transmitting moving assembly and the laser transmitting optical axis 9, and the position of the focusing focus of the transmitting laser is ensured to be always on the laser transmitting optical axis 9 in the moving process of the transmitting moving assembly; meanwhile, the processing control unit 7 ensures that the echo signal at the focus of the emitted laser is always coupled into the receiving optical fiber 44 at the focus of the receiving device 4 by adjusting the position of the receiving mobile component;
s4, calibrating according to the theoretical relation between the included angle alpha of the laser emission optical axis 9 and the laser receiving optical axis 10 and the positions of the emission mobile assembly and the receiving mobile assembly in the moving process of the emission mobile assembly and the receiving mobile assembly, so as to obtain the included angle between the laser emission optical axis 9 and the laser receiving optical axis 10 according to the translation amount of the emission mobile assembly and the receiving mobile assembly, and further obtain the measuring height of the radar;
s5, after the echo signals with the designated height pass through the coupler 5 and the local oscillation light beat frequency, the photoelectric differential detector 6 converts the beat frequency signals which are the optical signals into electric signals, and the electric signals are transmitted to the processing control unit 7 for fast Fourier transformation, so that the radial wind speed of the current point is obtained.
When the system further includes the laser reflection unit 3, in step S1, the angles of the laser emission lens 31 and the laser receiving lens 32 in the laser reflection unit 3 need to be adjusted so that the laser emission optical axis 9 of the emission device 2 and the laser receiving optical axis 10 of the receiving device 4 are located on the same plane; in step S3, when the moving direction of the output end face of the emission optical fiber 24 changes with the included angle of the laser emission optical axis 9, the emission optical adjusting lens 31 is moved to realize the coincidence of the emission light edge and the upper edge of the blade prism; meanwhile, the receiving optical adjusting lens 32 is moved, so that the included angle between the laser transmitting optical axis 9 and the laser receiving optical axis 10 is as small as possible on the premise that the transmitting device 2 and the receiving device 4 keep no light cutting.
In order to realize the most basic principle of the present application, the laser reflection unit 3 in fig. 1 is removed to obtain a schematic diagram as shown in fig. 2.
In the figure, the X-O-Y plane represents a plane a in which the emission optical axis 9 and the laser receiving optical axis 10 are located, the displacement planes of the emission translation stage 22 and the receiving translation stage 42 are parallel to the plane a, the Y axis is parallel to the laser receiving optical axis 10, and the X axis is parallel to the central line of the first beam expander 23 and the second beam expander 43. The output end face of the transmitting optical fiber 24 mounted thereon is moved accordingly by the transmitting translation stage 22, causing the orientation of the transmitting optical axis 9 to change in the a-plane. The distance between the system and the position of the intersection of the laser light emitting axis 9 and the laser light receiving axis 10 represents the detection distance of the radar. The driving movement direction of the receiving translation stage 42 is parallel to or coincides with the laser receiving optical axis 10, and the corresponding optical fiber end surfaces are respectively and simultaneously driven to move at the transmitting translation stage 22 and the receiving translation stage 42, so that the focus of the air scattering signal at the intersection point of the laser transmitting optical axis 9 and the laser receiving optical axis 10 on the second beam expander 43 just falls on the input end surface of the receiving optical fiber 44.
The output end face of the transmitting optical fiber 24 is driven to move by the transmitting translation stage 22The position of the focal point of the radiation beam is also changed, and the installation angle β of the radiation translation stage 22 is calculated by calculating such that the radiation beam focal point is exactly at the intersection point of the laser radiation optical axis 9 and the laser receiving optical axis 10 when the output end face of the radiation optical fiber 24 is moved in the moving direction. The method for determining the included angle alpha comprises the following steps: firstly, determining the distance delta between the center point of the first beam expander 23 and the center point of the second beam expander 43; next, a virtual measuring point (x, y) is determined on the laser receiving optical axis 10, the included angle alpha between the laser transmitting optical axis 9 passing through the measuring point and the laser receiving optical axis 10 is calculated, and the center distance between the measuring point and the first beam expander 23 is calculatedWherein (x, y) 0 ) Is the center position coordinate of the second beam expander 43. Then, the image distance v of the measurement point imaged by the first beam expander 23 is calculated according to the object-image relationship. Finally, the output end face position coordinates (x ', y') of the transmitting optical fiber 24 are calculated:
by the above formula, two groups of included angles α and the coordinates of the positions of the output end surfaces of the corresponding transmitting optical fibers 24 are calculated, and the installation angle β of the transmitting translation stage 22 is calculated.
After the theoretical relationship among the position coordinates of the output end face of the transmitting optical fiber 24, the focusing focal point coordinates of the transmitting laser, and the installation angle β of the transmitting translation stage 22 is obtained, the relationship between the displacement amount of the transmitting translation stage 22 and the included angle α of the laser transmitting optical axis 9 and the laser receiving optical axis 10 can be easily calculated according to the geometric relationship. However, since the initial position of the emission translation stage 22 is relative, when the correspondence between the theoretical coordinate and the actual position is not established yet, it is necessary to calibrate the emission laser focusing positions (x, y) and the output end face positions (x ', y') of the emission optical fiber 24 once under the actual atmospheric condition, so as to achieve the correspondence between the theoretical coordinate system and the actual position. After calibration, the measurement height of the radar can be calculated according to the relation between the translational amount of the transmitting translational stage 22 and the included angle alpha.
The measured height and the position of the receiving translation stage 42 accord with the basic object-image relationship; after one calibration, the corresponding relationship between the object-image relationship and the position of the receiving translation stage 42 can be established. After the corresponding relation between the theoretical movement position and the actual position of the output end face of the transmitting optical fiber 24 and the input end face of the receiving optical fiber 44 is determined, the transmitting translation stage 22 and the receiving translation stage 42 can be quantitatively controlled by the processing control unit 7 under the actual atmospheric condition, so that the measurement of wind fields with different heights can be realized. In the application, the launching translation stage 22 only needs to move unidirectionally and does not need to move in one two-dimensional direction, so that the workload of adjusting the launching translation stage 22 is reduced, and meanwhile, a driving structure and a guiding structure which are required to move in one dimension can be saved, thereby saving the system cost.
According to the design, the Doppler frequency shift signal caused by the air movement with the height of 8 meters is measured in the actual atmosphere, and the test result is shown in fig. 3; the test result proves that the application has the capability of measuring the atmospheric wind field within 10 meters at low altitude, thereby achieving the expected purpose. At the same time, by electrically controlling the positions of the transmitting translation stage 22 and the receiving translation stage 42, doppler frequency shift signals are caused for the wind speeds of 16 meters in height and 280 meters in height.
The atmospheric visibility of the test period was measured by using a visibility meter, and the measurement result showed that the visibility exceeded 50 km, which was a very clean air test condition. The lower the visibility, the stronger the echo signal, the easier the test, and the higher the visibility, the more difficult the test is. In addition, in order to further verify the system capacity, the whole system is arranged on a supporting platform, a two-dimensional scanning turntable is arranged below the supporting platform, and the two-dimensional scanning turntable realizes rotation in the horizontal plane direction and rotation in the vertical direction. The measured Doppler shift signal of 280 meters in height varies with the azimuth angle of rotation of the two-dimensional turntable as shown in FIG. 4. The system can obtain Doppler frequency shift signals with 8 meters height, particularly 280 meters height at the low altitude under the clean atmosphere condition that the visibility exceeds 50 km based on the rotation azimuth angle of the two-dimensional turntable, the experimental result is shown in fig. 5, and the experimental result verifies that the method can measure not only low altitude wind fields but also wind fields with other heights, and proves the feasibility of the adopted method.
The above embodiments are merely preferred embodiments of the present application and are not intended to limit the present application, and any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of the present application.
Claims (5)
1. An improved quasi-blind area-free Doppler coherent laser radar wind speed measurement system is characterized by comprising a transmitting device (2) and a receiving device (4), wherein an included angle alpha is formed between a laser transmitting optical axis (9) transmitted to the atmosphere by the transmitting device (2) and a laser receiving optical axis (10) of the receiving device (4), and the included angle alpha is adjustable;
the system also comprises a laser reflection unit (3), wherein the laser reflection unit (3) comprises an emission optical regulation lens (31), a receiving optical regulation lens (32) and a blade prism (33), the emission optical regulation lens (31) reflects incident light emitted by the emission device (2) to the upper edge position of one coating surface of the blade prism (33) and then reflects the incident light to the atmosphere, and the receiving optical regulation lens (32) continues to reflect the received light to a second beam expander (43) in the receiving device (4) after the upper edge position of the other coating surface of the blade prism (33) reflects the received light to the receiving optical regulation lens (32);
the emitting device (2) comprises an emitting optical fiber (24) and a first beam expander (23) which are sequentially arranged on a laser emitting optical axis (9), main vibration light is transmitted through the emitting optical fiber (24) and then emitted out of the emitting device (2) through the first beam expander (23), and an emitting moving assembly for driving the end face to move is further arranged at the output end face of the emitting optical fiber (24);
the receiving device (4) comprises a second beam expander (43) and a receiving optical fiber (44) which are sequentially arranged on a laser receiving optical axis (10), wherein receiving light passing through the second beam expander (43) is input into an input end face of the receiving optical fiber (44), and a receiving moving assembly for adjusting the position of the end face is arranged at the input end face of the receiving optical fiber (44);
the emission moving assembly comprises a first fixing piece (21) for fixing the output end face of the emission optical fiber (24), and an emission translation table (22), wherein the emission translation table (22) is used for fixing the first fixing piece (21) and driving the optical fiber end face on the first fixing piece to move in a set direction; similarly, the receiving moving assembly comprises a second fixing piece (41) for fixing an input end face of the receiving optical fiber (44), and a receiving translation table (42), wherein the receiving translation table (42) is used for fixing the second fixing piece (41) and driving the optical fiber end face on the second fixing piece to move in a set direction.
2. The improved quasi-blind area-free doppler coherent lidar wind speed measurement system of claim 1, wherein the angle of the transmit optical adjustment lens (31) and the receive optical adjustment lens (32) is adjustable.
3. The improved quasi-blind area-free doppler coherent laser radar wind speed measurement system according to claim 1, characterized in that a diaphragm (8) is mounted on the blade prism (33) in a direction parallel to the laser receiving optical axis (10).
4. The improved quasi-blind area-free doppler coherent lidar wind speed measurement system according to claim 1, characterized in that the system further comprises a laser generating unit (1), the laser generating unit (1) comprising a laser (11), the laser (11) emitting laser light being a pulsed laser or a continuous laser.
5. A method of using the improved quasi-blind area free doppler coherent lidar wind speed measurement system of any of claims 1 to 4, characterized in that the system further comprises a laser reflection unit (3), a coupler (5), a photo differential detector (6), a process control unit (7), the method comprising the steps of:
s1, adjusting a transmitting device (2) and a receiving device (4) to enable a laser transmitting optical axis (9) of the transmitting device (2) and a laser receiving optical axis (10) of the receiving device (4) to be located on the same plane, wherein the plane is a plane A; the angles of the laser transmitting lens (31) and the laser receiving lens (32) in the laser reflecting unit (3) are required to be adjusted, so that the laser transmitting optical axis (9) of the transmitting device (2) and the laser receiving optical axis (10) of the receiving device (4) are positioned on the same plane;
s2, determining displacement surfaces of the transmitting mobile assembly and the receiving mobile assembly, and ensuring that the displacement surfaces of the transmitting mobile assembly and the receiving mobile assembly are parallel to a plane A;
s3, a processing control unit (7) controls the moving direction of the transmitting moving assembly so as to change the included angle between the laser transmitting optical axis (9) and the laser receiving optical axis (10), and the position of the focusing focus of the transmitting laser is ensured to be always on the laser transmitting optical axis (9) in the moving process of the transmitting moving assembly according to the set angle; meanwhile, the processing control unit (7) ensures that an echo signal at the focus of the emitted laser is always coupled into the receiving optical fiber (44) at the focus of the receiving device (4) by adjusting the position of the receiving mobile component; when the included angle between the moving direction of the output end face of the emitting optical fiber (24) and the laser emitting optical axis (9) is changed, the emitting optical adjusting lens (31) is moved to enable the emitting light edge to coincide with the upper edge of the knife edge prism; meanwhile, the receiving optical adjusting lens (32) is moved, so that the included angle between the laser emission optical axis (9) and the laser receiving optical axis (10) is as small as possible on the premise that the emission device (2) and the receiving device (4) keep no light cutting;
s4, calibrating according to the theoretical relation between the included angle alpha of the laser emission optical axis (9) and the laser receiving optical axis (10) and the positions of the emission mobile assembly and the receiving mobile assembly in the moving process of the emission mobile assembly and the receiving mobile assembly, so as to obtain the included angle between the laser emission optical axis (9) and the laser receiving optical axis (10) according to the translation amount of the emission mobile assembly, and further obtain the measuring height of the radar;
s5, after the echo signals with the designated height pass through the coupler (5) and the beat frequency of the local oscillation light, the photoelectric differential detector (6) converts the beat frequency signals which are the optical signals into electric signals, and the electric signals are transmitted to the processing control unit (7) for fast Fourier transformation, so that the radial wind speed of the current point is obtained.
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| CN113540950B (en) * | 2021-07-15 | 2023-03-14 | 中国人民解放军国防科技大学 | Electro-optic modulation depth real-time measurement and control system and method based on VIPA etalon |
| EP4379422A1 (en) * | 2021-08-17 | 2024-06-05 | Huawei Technologies Co., Ltd. | Transceiver optical system, lidar, terminal device, and method and apparatus |
| CN114265016B (en) * | 2021-12-28 | 2023-04-14 | 河北德冠隆电子科技有限公司 | Multi-angle adjustment wide area radar sensor system and method |
| CN114706099B (en) * | 2022-06-07 | 2022-11-22 | 成都凯天电子股份有限公司 | Laser wind finding radar optical module and measuring method thereof |
| CN117434296B (en) * | 2023-12-15 | 2024-03-15 | 南京牧镭激光科技股份有限公司 | Method, equipment and storage medium for measuring wind speed of fan impeller surface by laser double radars |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11304924A (en) * | 1998-04-23 | 1999-11-05 | Mitsubishi Electric Corp | Coherent lidar |
| CN1340699A (en) * | 2000-08-24 | 2002-03-20 | 中国科学院大气物理研究所 | Device for regulating parallelism between emitting and receiving optical axes of multi-wavelength laser radar |
| WO2004092767A1 (en) * | 2003-04-10 | 2004-10-28 | Eads Deutschland Gmbh | Method for detecting wind speeds using a doppler-lidar system, especially on aeroplanes, and doppler-lidar system |
| CN1932553A (en) * | 2006-09-30 | 2007-03-21 | 中国海洋大学 | Microwave windfinding laser radar apparatus |
| CN102353950A (en) * | 2011-10-18 | 2012-02-15 | 中国工程物理研究院应用电子学研究所 | Laser radar optical system with optical axis calibrating function and optical axis calibrating method |
| CN104007069A (en) * | 2014-05-20 | 2014-08-27 | 中国科学院合肥物质科学研究院 | Differential optical absorption spectroscopy measurement system based on off-axis paraboloid mirror |
| JP2015031648A (en) * | 2013-08-06 | 2015-02-16 | 株式会社東京精密 | Laser tracker |
| WO2016092705A1 (en) * | 2014-12-12 | 2016-06-16 | 三菱電機株式会社 | Laser radar device |
| CN108717195A (en) * | 2018-05-24 | 2018-10-30 | 远景能源（江苏）有限公司 | A kind of coherent Doppler wind-observation laser radar system and its control method |
| EP3462209A1 (en) * | 2016-08-10 | 2019-04-03 | Mitsubishi Electric Corporation | Optical axis adjustment mechanism and lidar device |
| CN109738880A (en) * | 2019-03-26 | 2019-05-10 | 深圳市镭神智能系统有限公司 | A kind of laser radar system and laser ranging system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5973779A (en) * | 1996-03-29 | 1999-10-26 | Ansari; Rafat R. | Fiber-optic imaging probe |
| JP6163821B2 (en) * | 2013-03-27 | 2017-07-19 | 三菱電機株式会社 | Optical transmitter and optical receiver |
| CN107783144A (en) * | 2017-10-30 | 2018-03-09 | 南京牧镭激光科技有限公司 | Windfinding laser radar apparatus |
-
2019
- 2019-07-08 CN CN201910608446.5A patent/CN110308454B/en active Active
- 2019-07-08 CN CN202011490655.3A patent/CN112711031B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11304924A (en) * | 1998-04-23 | 1999-11-05 | Mitsubishi Electric Corp | Coherent lidar |
| CN1340699A (en) * | 2000-08-24 | 2002-03-20 | 中国科学院大气物理研究所 | Device for regulating parallelism between emitting and receiving optical axes of multi-wavelength laser radar |
| WO2004092767A1 (en) * | 2003-04-10 | 2004-10-28 | Eads Deutschland Gmbh | Method for detecting wind speeds using a doppler-lidar system, especially on aeroplanes, and doppler-lidar system |
| CN1932553A (en) * | 2006-09-30 | 2007-03-21 | 中国海洋大学 | Microwave windfinding laser radar apparatus |
| CN102353950A (en) * | 2011-10-18 | 2012-02-15 | 中国工程物理研究院应用电子学研究所 | Laser radar optical system with optical axis calibrating function and optical axis calibrating method |
| JP2015031648A (en) * | 2013-08-06 | 2015-02-16 | 株式会社東京精密 | Laser tracker |
| CN104007069A (en) * | 2014-05-20 | 2014-08-27 | 中国科学院合肥物质科学研究院 | Differential optical absorption spectroscopy measurement system based on off-axis paraboloid mirror |
| WO2016092705A1 (en) * | 2014-12-12 | 2016-06-16 | 三菱電機株式会社 | Laser radar device |
| EP3462209A1 (en) * | 2016-08-10 | 2019-04-03 | Mitsubishi Electric Corporation | Optical axis adjustment mechanism and lidar device |
| CN108717195A (en) * | 2018-05-24 | 2018-10-30 | 远景能源（江苏）有限公司 | A kind of coherent Doppler wind-observation laser radar system and its control method |
| CN109738880A (en) * | 2019-03-26 | 2019-05-10 | 深圳市镭神智能系统有限公司 | A kind of laser radar system and laser ranging system |
Non-Patent Citations (1)
| Title |
|---|
| 王迎强 ; .相干多普勒激光雷达技术.雷达科学与技术.2007,(第02期),第100-105页. * |
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