CN219936106U - Laser radar system - Google Patents
Laser radar system Download PDFInfo
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- CN219936106U CN219936106U CN202320899364.2U CN202320899364U CN219936106U CN 219936106 U CN219936106 U CN 219936106U CN 202320899364 U CN202320899364 U CN 202320899364U CN 219936106 U CN219936106 U CN 219936106U
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- 230000003287 optical effect Effects 0.000 claims abstract description 26
- 238000012545 processing Methods 0.000 claims abstract description 26
- 239000013307 optical fiber Substances 0.000 claims abstract description 24
- 238000001514 detection method Methods 0.000 claims description 23
- 239000000835 fiber Substances 0.000 claims description 17
- 238000002310 reflectometry Methods 0.000 claims description 7
- 101100456571 Mus musculus Med12 gene Proteins 0.000 claims 1
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- 230000010355 oscillation Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
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- 230000008569 process Effects 0.000 description 4
- 230000035559 beat frequency Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
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- 230000025518 detection of mechanical stimulus involved in sensory perception of wind Effects 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
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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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Abstract
The utility model proposes a lidar system comprising: the output end of the seed source laser is connected with the input end of the optical fiber beam splitter; two output ends of the optical fiber beam splitter are respectively connected with the input end of the acousto-optic modulator and the first input end of the coupler; the output end of the acousto-optic modulator is connected with the input end of the optical fiber amplifier, and pulse laser is output to the first end of the circulator by the optical fiber amplifier; the second end of the circulator is connected with the input end of the telescope, the output end of the telescope is connected to the input end of the scanning assembly, and the third end of the circulator is connected to the second input end of the coupler; the optical coupler is connected with the balance detector; the output end of the balance detector is connected with the input end of the data acquisition card, the first control signal output end of the data acquisition card is connected with the signal input end of the scanning assembly, the second control signal output end is connected with the signal input end of the acousto-optic modulator, and the signal output end is connected with the signal input end of the signal processing board.
Description
Technical Field
The utility model belongs to the technical field of laser radars, and particularly relates to a laser radar system.
Background
Atmospheric detection is an important means for human research on aerodynamics and climate change, and particularly has very important roles in various fields such as wind power, military, environment, aviation, weather, ocean and the like, and particularly for detecting the height of an atmospheric wind field and a cloud layer. In the wind power field, wind resource exploration at the early stage of fan erection, yaw correction in the power generation process and wind power test are realized by wind measuring equipment; for military application fields, personnel, equipment parachuting, gun shooting and other military operations, weather protection needs to be achieved through atmospheric wind field detection, and weather forecast of the military site needs to be judged by integrating the height information of local cloud layers. In the taking-off and landing process of the aviation aircraft, the detection of wind field and cloud layer information near the ground can ensure the flight safety.
At present, the main means of multi-element atmosphere detection are a sonde and a microwave radar. The detection scheme of the sonde can influence the safety of an airspace, aviation accidents are easy to cause, and the real-time performance of data cannot be guaranteed. The microwave radar is widely applied to the military field, the detection accuracy is limited by weather conditions, the detection performance of the microwave radar is poor under the condition of sunny days, and in addition, the microwave radar is easily interfered by an electromagnetic field.
Disclosure of Invention
In order to make up for the defects of the prior art, the utility model provides a laser radar system.
The technical scheme adopted for solving the technical problems is as follows:
a lidar system, comprising: the device comprises a pulse fiber laser module, an optical path control and receiving and transmitting module, a balance detection module and a signal processing module; wherein:
a pulsed fiber laser module comprising: the device comprises a seed source laser, an optical fiber beam splitter, an acousto-optic modulator and an optical fiber amplifier;
the optical path control and receiving-transmitting module includes: the device comprises a circulator, a telescope and a scanning assembly;
a balance detection module, comprising: an optical coupler, a balance detector;
a signal processing module, comprising: the data acquisition card and the signal processing board;
the output end of the seed source laser is connected with the input end of the optical fiber beam splitter; one of the two output ends of the optical fiber beam splitter is connected with the input end of the acousto-optic modulator, and the other output end of the optical fiber beam splitter is connected with the first input end of the coupler; the output end of the acousto-optic modulator is connected with the input end of the optical fiber amplifier, and pulse laser is output to the first end of the circulator by the optical fiber amplifier; the second end of the circulator is connected with the input end of the telescope, the output light of the telescope is sequentially reflected to the atmosphere in a plurality of directions through the scanning assembly, and the generated back scattered light signals are received and returned to the input end of the telescope; the third end of the circulator is connected to the second input end of the coupler; two output ports of the optical coupler are simultaneously connected to two input ends of the balance detector; the output end of the balance detector is connected with the input end of the data acquisition card, the first control signal output end of the data acquisition card is connected with the signal input end of the scanning assembly, the second control signal output end of the data acquisition card is connected with the signal input end of the acousto-optic modulator, and the signal output end of the data acquisition card is connected with the signal input end of the signal processing board.
Preferably, the scanning assembly includes: two high reflectivity flat mirrors and a servo system for controlling the movement of the flat mirrors.
Preferably, the two high reflectivity flat mirrors are disposed at 45 degrees to the respective rotation axes, wherein the rotation axis of the first flat mirror coincides with the optical axis of the telescope, and the rotation axis of the second flat mirror is perpendicular to the optical axis and passes through the center of the first mirror.
Preferably, the balanced detector employs heterodyne circuitry to reduce noise in the detected signal.
Preferably, the fiber amplifier comprises a fiber laser amplifier in the form of a multistage amplified MOPA.
The beneficial effects of the utility model are as follows:
the utility model provides an implementation scheme of a laser radar system capable of detecting an atmospheric wind field and cloud layer height simultaneously, which integrates the laser radar system technology and the laser atmospheric cloud height detection technology in principle and system, realizes the atmospheric multi-parameter detection of the laser radar and has the advantages of high resolution, small volume, low cost, full functions and electromagnetic interference resistance.
Drawings
The utility model is further described below with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of a lidar system according to the present utility model.
Detailed Description
The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.
In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.
As shown in fig. 1, the lidar system according to the present utility model includes: the device comprises a pulse fiber laser module 1, an optical path control and receiving and transmitting module 4, a balance detection module 2 and a signal processing module 3.
The pulse fiber laser module 1 has the following functions: generating pulse laser signals, for example, the single pulse energy of the pulse laser is between 10 and 150uj, the pulse width of the pulse is between 50 and 400ns, the repetition frequency of the pulse is between 5 and 30kHz, the on-off extinction ratio of the pulse laser is more than 80dB, and the linewidth of the laser signals is less than 50kHz.
In one embodiment, the pulsed fiber laser module 1 comprises: a seed source laser 5, a fiber beam splitter 6, an acousto-optic modulator 7 and a fiber amplifier 8. The seed source laser 5 is, for example, a single-frequency laser, the linewidth of which is smaller than 50kHz, and the output power of which is larger than 20mw. The optical fiber beam splitter 6 is used for realizing the light splitting of the light path and divides the laser light of the seed source laser 5 into two according to a specific proportion. The acousto-optic modulator 7 can realize on-off modulation and frequency shift modulation of laser. The fiber Amplifier 8 may take the form of a multi-stage amplified MOPA (Master Oscillator Power-Amplifier, master oscillator power Amplifier) fiber laser Amplifier.
The optical path control and receiving-transmitting module 4 has the functions of: the signal of the pulse laser is transmitted to the atmosphere, the change of the emergent direction of the pulse laser signal is realized, and the echo signal generated by the atmospheric scattering is collected into the balance detection module 2.
In one embodiment, the optical path control and transceiver module 4 includes: circulator 9, telescope 10, scanning assembly. The telescope 10 is used for realizing beam expansion of light beams, and collimating and expanding pulse laser emitted by an optical fiber. The scanning assembly may be comprised of two high reflectivity mirrors and a servo system to control their motion. Preferably, the two high-reflectivity plane mirrors are arranged at 45 degrees with respect to the respective rotation axes, wherein the rotation axis of the first plane mirror coincides with the optical axis of the telescope, and the rotation axis of the second plane mirror is perpendicular to the optical axis and passes through the center of the first plane mirror. Wherein the first plane mirror is earlier than the second plane mirror in the emergent light path.
The function of the balance detection module 2 is: the optical signal is converted into an electrical signal. The balance detection module enables the laser radar system to perform beat frequency processing on the atmosphere echo signal and the local oscillation light and generate Doppler frequency shift electric signals.
In one embodiment, the balance detection module 2 comprises: an optical coupler 11, and a balance detector 12. The optocoupler 11 has four ports, two input ends and two output ends, and the splitting ratio of the two output ends can be 1:1. In one embodiment, the detection principle of the balanced detector is coherent balanced detection. Preferably, balanced detector 12 may employ heterodyne circuitry to reduce noise in the detected signal.
The function of the signal processing module 3 is: and the electric signal is processed, and the wind field and cloud height information of the atmosphere to be detected are output. The signal processing module 3 can also control the scanning component to realize optical path scanning, and simultaneously control the acousto-optic modulator 7 to convert continuous light into pulse light.
In an embodiment, the signal processing module 3 comprises: a data acquisition card 13 and a signal processing board 14.
As shown in fig. 1, specifically, the output end of the seed source laser 5 is connected to the input end of the fiber optic beam splitter 6; one of the two output ends of the optical fiber beam splitter 6 is connected with the input end of the acousto-optic modulator 7, and the other output end is connected with the first input end of the coupler 11; the output end of the acousto-optic modulator 7 is connected with the input end of the optical fiber amplifier 8, and pulse laser is output to the first end of the circulator 9 by the optical fiber amplifier 8; the second end of the circulator 9 is connected with the input end of the telescope 10, the output light of the telescope is sequentially reflected to the atmosphere in a plurality of directions through the scanning assembly, and the third end of the circulator 9 is connected with the second input end of the coupler 11; the two outputs of the optocoupler 11 are simultaneously connected to the two inputs of the balance detector 12; the output end of the balance detector 12 is connected with the input end of the data acquisition card 13, the first control signal output end of the data acquisition card 13 is connected with the signal input end (not shown in the figure) of the scanning component, the second control signal output end of the data acquisition card 13 is connected with the signal input end of the acousto-optic modulator 7, and the signal output end of the data acquisition card 13 is connected with the signal input end of the signal processing board 14.
The working process of the laser radar system provided by the utility model is as follows: the continuous laser light emitted from the seed source laser 5 is split into two signal lights by the beam splitter 6, one of the signal lights is transmitted to the input end of the acousto-optic modulator 7 as signal light to be modulated, and the other signal light is transmitted to the first input end of the coupler 11 as local oscillation light. The acousto-optic modulator 7 modulates the local oscillation signal light to become pulse signal light and generates a frequency shift. The optical fiber amplifier 8 amplifies the pulse optical signal, the amplified pulse optical signal is transmitted to the first end of the circulator 9, and then is output to the input end of the telescope 10 by the second end of the circulator 9, and the two high-reflectivity plane mirrors 15 and 16 in the scanning assembly are controlled by the motor, so that the laser emergent angles are 1, 2, 3, 4 and 5, wherein the 1 direction is vertical ground upwards, the 2-bit direction is upwards 30 degrees in the east oblique direction, the 3-bit direction is upwards 30 degrees in the south oblique direction, the 4-bit direction is upwards 30 degrees in the west oblique direction, and the 5-bit direction is upwards 30 degrees in the north oblique direction. The control instruction of the motor is controlled by the electric signal sent by the data acquisition card 13, so that the pulse light signals are alternately output to the atmosphere from the above five directions. The atmosphere produces a back-scattering of the pulsed light signal, which is received by the same lens and returned to the input of the telescope 10, and then input to the circulator 9 via the second end of the circulator 9, the circulator 9 outputting the echo signal from the third end to the second input of the coupler 11. The coupler 11 couples the echo signal and the local oscillation light received by the first input end to two input ends of the balance detector 12, and in the process, beat frequency of the echo signal and the local oscillation light is completed. The balanced detector 12 detects the beat frequency optical signal and converts the optical signal into a Doppler shift signal related to the velocity of the atmospheric motion. The frequency shift signal enters the input end of the data acquisition card 13 from the output end of the balance detector 12, and the data acquisition card 13 performs analog-digital conversion on the frequency shift signal to convert the frequency shift signal into a digital signal, and finally outputs the digital signal to the signal processing board 14. The signal processing board carries out algorithm processing on the digital signals to obtain radial wind speed information corresponding to the moment detection lens. Next, the data acquisition card 13 sends out a timing pulse to realize the optical path switching of the scanning component, and the above workflow is repeated. Until all the radial wind speeds and the echo signal intensities in all the postures are collected by the signal processing board 14, and then the software algorithm of the signal processing board 14 calculates corresponding synthetic wind field information and cloud height information.
In order to verify the practicability of the laser radar system, the embodiment uses a telescope group as a receiving and transmitting antenna of the laser radar system. The experimental procedure was as follows:
step 101, according to the structural schematic diagram 1, a test link is built.
Step 102, turning on a seed source laser, and adjusting the output power of the seed source laser to be between 30 and 40 mw.
Step 103, starting an acousto-optic modulator, a fiber amplifier, a scanning assembly and a balance detector.
Step 104, starting a signal processing module, and sending a pulse modulation signal with a pulse width of 200ns and a repetition frequency of 20kHz to the acousto-optic modulator, wherein the acousto-optic modulator can generate a frequency shift of 80MHz, so that the acousto-optic modulator outputs pulse laser, and the pulse width is 20ns and the repetition frequency is 20kHz. Meanwhile, the signal processing module sends an instruction to the scanning assembly, so that two reflecting glasses in the scanning assembly are controlled by the motor, and the laser emergent angles are in directions 1, 2, 3, 4 and 5. The direction 1 is vertical to the ground and upwards 30 degrees in the eastern direction, the direction 2 is upwards 30 degrees in the eastern direction, the direction 3 is upwards 30 degrees in the southward direction, the direction 4 is upwards 30 degrees in the westernly direction, and the direction 5 is upwards 30 degrees in the northward direction. Pulse light signals are output to the atmosphere in turn from the five directions, echo signals in all directions are collected through signal processing in each direction, fourier transformation is carried out, and corresponding data caching is carried out.
Step 105, after the signal processing module finishes collecting and buffering the data in 5 directions, the wind profile power spectrum and the atmospheric backscattering curve of the laser radar system can be checked through an additional signal processing output display terminal. And obtaining corresponding cloud height information and corresponding profile information through a post-processing algorithm.
The utility model provides a multi-element meteorological detection scheme for simultaneously detecting an atmospheric wind field and a cloud layer height laser radar system, which integrates the laser radar system technology with the laser atmospheric cloud height detection technology on the principle and system, realizes the atmospheric multi-parameter detection of the laser radar, and has the advantages of high resolution, small volume, low cost, complete functions and electromagnetic interference resistance. The laser radar system can be applied to the fields of weather guarantee of military operations, taking-off and landing safety guarantee of aviation aircrafts, weather forecast and the like.
The foregoing has shown and described the basic principles, principal features and advantages of the utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims. The scope of the utility model is defined by the appended claims and equivalents thereof.
Claims (5)
1. A lidar system, comprising: the device comprises a pulse fiber laser module, an optical path control and receiving and transmitting module, a balance detection module and a signal processing module; wherein:
a pulsed fiber laser module comprising: the device comprises a seed source laser, an optical fiber beam splitter, an acousto-optic modulator and an optical fiber amplifier;
the optical path control and receiving-transmitting module includes: the device comprises a circulator, a telescope and a scanning assembly;
a balance detection module, comprising: an optical coupler, a balance detector;
a signal processing module, comprising: the data acquisition card and the signal processing board;
the output end of the seed source laser is connected with the input end of the optical fiber beam splitter; one of the two output ends of the optical fiber beam splitter is connected with the input end of the acousto-optic modulator, and the other output end of the optical fiber beam splitter is connected with the first input end of the coupler; the output end of the acousto-optic modulator is connected with the input end of the optical fiber amplifier, and pulse laser is output to the first end of the circulator by the optical fiber amplifier; the second end of the circulator is connected with the input end of the telescope, the output light of the telescope is sequentially reflected to the atmosphere in a plurality of directions through the scanning assembly, and the generated back scattered light signals are received and returned to the input end of the telescope; the third end of the circulator is connected to the second input end of the coupler; two output ports of the optical coupler are simultaneously connected to two input ends of the balance detector; the output end of the balance detector is connected with the input end of the data acquisition card, the first control signal output end of the data acquisition card is connected with the signal input end of the scanning assembly, the second control signal output end of the data acquisition card is connected with the signal input end of the acousto-optic modulator, and the signal output end of the data acquisition card is connected with the signal input end of the signal processing board.
2. The lidar system of claim 1, wherein the scanning assembly comprises: two high reflectivity flat mirrors and a servo system for controlling the movement of the flat mirrors.
3. The lidar system of claim 2, wherein the two high-reflectivity mirrors are disposed at 45 degrees to respective axes of rotation, wherein the axis of rotation of the first mirror coincides with the optical axis of the telescope and the axis of rotation of the second mirror is perpendicular to the optical axis and passes through the center of the first mirror.
4. The lidar system of claim 1, wherein the balanced detector comprises a heterodyne circuit to reduce noise in the detected signal.
5. The lidar system of claim 1, wherein the fiber amplifier comprises a fiber laser amplifier in the form of a multi-stage amplification MOPA.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320899364.2U CN219936106U (en) | 2023-04-20 | 2023-04-20 | Laser radar system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202320899364.2U CN219936106U (en) | 2023-04-20 | 2023-04-20 | Laser radar system |
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| CN219936106U true CN219936106U (en) | 2023-10-31 |
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| CN202320899364.2U Active CN219936106U (en) | 2023-04-20 | 2023-04-20 | Laser radar system |
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