CN216310259U - Near-field signal modulation and three-direction fluorescence receiving device for laser radar - Google Patents

Abstract

The utility model discloses a near-field signal modulation and three-direction fluorescence receiving device for a laser radar, which comprises a shell, an optical fiber, an optical lens assembly, a chopping disk, a motor and a photoelectric detector, wherein the shell is provided with a plurality of optical fibers; an arc-shaped sliding rail is arranged on the shell, and a fastening assembly is arranged on the sliding rail; the optical fiber is assembled with the fastening component through the optical fiber connector, and the optical fiber slides and is locked on the sliding rail through the fastening component; the optical lens component is packaged in the shell and is optically coupled with the optical fiber; the chopper disk is positioned between the optical fiber and the optical lens component, is provided with a light through hole and a light screen, and is driven by a motor to rotate; the photoelectric detector is used for performing photoelectric conversion processing on an optical signal output by the optical lens assembly. The laser radar receiving system can not only chop the saturation signal returned by the low altitude to improve the photoelectric response of the photoelectric detector; and the modulation can be realized for the chopping height of the near-field signal of the laser radar, and the consistency of the chopping height of the near-field signal in three directions is realized.

Description

Near-field signal modulation and three-direction fluorescence receiving device for laser radar

Technical Field

The utility model belongs to the technical field of atmospheric environment monitoring equipment, relates to a laser radar, and particularly relates to a signal receiving device for the laser radar.

Background

The laser radar is an active remote sensing monitoring device and has the advantages of high space-time resolution, high measurement accuracy and the like. In recent years, with the development of laser technology and photoelectric detection technology, laser radars are gradually applied to the detection and research field of middle and high-rise atmosphere. In order to meet the requirement of the laser radar for measuring the three-dimensional wind field of the high-rise atmosphere, a receiving system of the laser radar is required to be capable of receiving laser fluorescence echo signals in three directions (such as vertical direction, east direction and north direction) at the same time, and high-sensitivity detection can be realized on weak optical fluorescence signals returned by the high-rise atmosphere (80-120 km away from the ground) in the three directions, so that the requirement of measuring the wind speed in each direction is met.

If the receiving system of the laser radar receives in a single direction and the detection height is low, high laser energy is not needed, and low-altitude saturation can not occur, so that when a receiving optical path is designed, special processing on a received low-altitude signal is not needed, and the requirement on the overall design of the receiving optical path is not high.

If the laser radar is used for measuring a middle and high-rise atmospheric wind field, three-direction observation data are needed to perform inversion of a three-dimensional wind field in the atmosphere. At this time, the receiving system in a single direction cannot meet the signal receiving requirement, and a three-direction weak optical fluorescence signal receiving system needs to be designed. In a three-direction fluorescent signal receiving system, in order to ensure the collimation of the receiving light path in each detection direction so as to improve the receiving efficiency of signals, the receiving light paths in three directions need to be redesigned. In addition, when the high and medium-altitude atmosphere is detected, the detection distance is long, and high laser energy is needed, so that the low-altitude signal is easily saturated, and therefore, in a receiving system, the receiving light paths in three directions need to be chopped, so that the influence of the low-altitude signal saturation problem on the photoelectric detector in the process of collecting the high-altitude signal is reduced. However, when the low-altitude signals in the three directions are chopped simultaneously, there is a problem that the chopping heights of the low-altitude signals in the three directions are not uniform, which affects the signal processing in the later stage, and therefore, it is necessary to modulate the near-field signal of the laser radar.

Disclosure of Invention

The utility model aims to provide a near-field signal modulation and three-direction fluorescence receiving device for a laser radar, which can chop three-direction saturated signals returned by the laser radar at low altitude and can modulate the chopping height of the near-field signal of the laser radar.

In order to solve the technical problems, the utility model adopts the following technical scheme:

a near-field signal modulation and three-direction fluorescence receiving device for a laser radar comprises a shell, an optical fiber, an optical lens assembly, a chopping disk, a motor and a photoelectric detector; the shell comprises a front panel and a rear panel which are in relative position relation, the front panel is provided with three arc-shaped slide rails, and each slide rail is provided with a fastening component with adjustable tightness; the optical fibers comprise three optical fibers and are used for receiving laser fluorescence echo signals from three directions; each optical fiber is provided with an optical fiber connector, the three optical fibers are correspondingly assembled with the fastening components on the three slide rails through the respective optical fiber connectors, and the optical fibers slide and are locked on the slide rails through the fastening components; the optical lens assembly comprises three paths, is packaged in the shell, is optically coupled with the three optical fibers in a one-to-one correspondence mode, and is used for respectively carrying out collimation and convergence processing on three paths of optical signals emitted by the three optical fibers; the chopper disk is sealed in the shell and positioned between the optical fiber and the optical lens assembly, a plurality of light through holes distributed along the circumferential direction are formed in the chopper disk, and a light shielding plate is formed between every two adjacent light through holes; the motor is arranged on the shell and is in shaft connection with the chopping disk and used for driving the chopping disk to rotate so that the light shielding plate and the light through hole alternately pass through the light incidence end face of the optical lens assembly; the photoelectric detector comprises three paths, is arranged on the rear panel of the shell, is optically coupled with the three paths of optical lens assemblies in a one-to-one correspondence mode, and is used for carrying out photoelectric conversion processing on optical signals output by the three paths of optical lens assemblies.

In some embodiments of the present application, in order to provide a time reference for the light emitting timing of the laser and the collection timing of the echo signal, a photoelectric sensor is further provided in the laser radar receiving system, the photoelectric sensor is mounted on the front panel of the housing, and when the chopping disk rotates, the light shielding plate and the light through hole alternately pass through the photosensitive surface of the photoelectric sensor to generate a detection signal in a pulse form, and the detection signal is sent to a control circuit of the laser radar to realize timing control. The control circuit is also used for receiving detection signals output by the photoelectric detector and controlling the working state of the motor.

In some embodiments of the present application, the photoelectric sensor and the three optical fibers are preferably arranged in a circumferential manner on the front panel of the housing, so as to be matched with a chopper plate, so as to realize chopping of low-altitude saturated signals and collection of high-altitude anemometry signals.

In some embodiments of the present application, it is preferable that the chopper plate is designed to be a disk shape on which four light passing holes and four light shielding plates are formed; preferably, the central angles of the four light through holes and the four light shielding plates are designed to be equal and are alternately and uniformly distributed on the disc; and in the rotation process of the chopping disk, the four light through holes of the chopping disk are respectively opposite to the photoelectric sensor and the three optical lens components one by one, so that the modulation requirements of the near-field signals of the laser radar on different chopping heights are met.

In some embodiments of the present application, in order to simplify the structural design, it is preferably designed that the slide rail penetrates through the front panel of the housing, a light shielding disc is installed on the fastening component, the light shielding disc shields other parts except the fastening component on the slide rail, so as to prevent ambient light from entering the housing through the slide rail, and generate interference on accurate reception of the laser fluorescence echo signal.

In some embodiments of the present application, the fastening assembly includes a fastening screw and a fastening nut; preferably, the fastening screw is designed into a hollow tube shape, inserted into the slide rail and in threaded connection with the optical fiber connector of the optical fiber, so that an optical signal emitted through the optical fiber can be smoothly incident to the optical lens assembly through the hollow area of the fastening screw, and accurate conduction of a laser fluorescence echo signal is realized; and the fastening nut is in threaded connection with the fastening screw so as to be used for screwing and fixing the fastening screw on the slide rail to realize the positioning of the optical fiber on the slide rail, and the position of the optical fiber on the slide rail can be adjusted by unscrewing the fastening nut.

In some embodiments of the present application, the optical lens assembly includes a lens barrel, a collimating lens, an interference filter, and a condensing lens; the lens cone is provided with a light incidence end face and a light emergence end face which are in a relative position relation; the collimating lens is arranged in the lens barrel, is positioned on one side of the light incidence end face of the lens barrel and is used for optically coupling with the optical fiber; the interference filter is arranged in the lens barrel, is positioned behind the collimating lens in the light transmission direction and is used for filtering interference light in the collimated light emitted by the collimating lens; the converging lens is arranged in the lens barrel, is positioned on one side of the light emergent end face of the lens barrel and is used for being optically coupled with the photoelectric detector.

In some embodiments of the present application, the collimating lens is preferably an aspheric collimating lens to better optically collimate the planar divergent light source exiting through the optical fiber.

In some embodiments of the present application, the photo detector preferably employs a photomultiplier tube, and the photomultiplier tube is provided with a heat sink and a heat dissipation fan for cooling the photomultiplier tube, so as to ensure that the photoelectric conversion efficiency of the photomultiplier tube is not changed due to temperature rise, thereby realizing high-sensitivity detection of weak optical signals.

In some embodiments of the present application, the photodetector is preferably mounted outside the back panel of the housing to facilitate rapid heat dissipation from the photodetector during operation.

Compared with the prior art, the utility model has the advantages and positive effects that: the laser radar receiving device can not only realize the accurate receiving of the three-direction laser fluorescence echo signals returned by the middle-high atmosphere when the laser radar detects the omnidirectional wind field of the middle-high atmosphere; and through designing the chopping disk, the saturated signal returned by the low altitude can be chopped, so that the photoelectric response of the photoelectric detector to the high altitude fluorescence echo signal is improved. Simultaneously, to the circular-arc slide rail of the adjustable optic fibre position of three optic fibre designs, can adjust the not equidirectional laser radar near field signal's of regulation chopper height from this to realize the high uniformity of the laser radar near field signal chopper of three direction, then eliminated because of the high nonconformity of the low latitude signal chopper of three direction and lead to the difficult problem of post signal processing.

Other features and advantages of the present invention will become more apparent from the detailed description of the embodiments of the present invention when taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic overall structure diagram of an embodiment of a near-field signal modulation and three-directional fluorescence receiving apparatus for a lidar according to the present invention;

FIG. 2 is a schematic view of the receiver shown in FIG. 1 with a front panel of the housing removed;

FIG. 3 is a schematic structural view of a slide rail, a fastening assembly and a shading plate;

FIG. 4 is a schematic diagram of a laser radar near-field signal chopping height modulation process;

FIG. 5 is a diagram of the position relationship between the optical lens in the lens barrel and the photosensitive surface of the photodetector and an optical path diagram;

fig. 6 is a rear view of the receiving device shown in fig. 1.

Detailed Description

The following detailed description of embodiments of the utility model refers to the accompanying drawings.

It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, it should be noted that in the description of the present invention, the terms "mounted" and "connected" are to be interpreted broadly unless explicitly defined or limited otherwise. For example, it may be a fixed connection, a detachable connection or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In order to chop and modulate near-field echo signals of the laser radar in three directions, the receiving system of the laser radar of the present embodiment includes a housing 10, three optical fibers 21, 22, and 23, a chopping disk 40, three groups of optical lens assemblies 50, and three photodetectors 31, 32, and 33, which are shown in fig. 1, 2, and 6.

The housing 10 is preferably defined by a front panel 12 and a rear panel 13, an upper panel 11 and a lower panel 16, and a left side panel 15 and a right side panel 14, which are in a relative position, and the lower panel 16 is provided with a fixing screw hole 20, so that the housing 10 can be mounted on an optical flat plate for placing a receiving system in a laser radar by using a screw.

Three arc- shaped slide rails 17, 18, 19 are opened on the front panel 12 of the housing 10, as shown in fig. 1. The three arc- shaped slide rails 17, 18, 19 are distributed along the circumferential direction, and may be three arcs on the same circle. A fastening assembly 43 is mounted on each of the arc- shaped slide rails 17, 18, 19 for mounting the three optical fibers 21, 22, 23 on the three slide rails 17, 18, 19 in a one-to-one correspondence.

Since the chopping height of the laser fluorescence echo signal received by the laser radar is closely related to the chopping time of the chopping edge of the chopping disk 40, if the three optical fibers 21, 22, 23 are directly fixed to the front panel 12 of the housing 10, it is difficult to ensure the consistency of the chopping heights of the three-direction received signals. Therefore, the present embodiment designs three circular arc- shaped slide rails 17, 18 and 19 as shown in fig. 1 for performing chopper modulation on the near-field saturation signal of the laser radar.

As a preferred embodiment, the fastening assembly 43 may include a fastening screw 46 and a fastening nut 45, as shown in fig. 3. The fastening screw 46 is preferably designed as a hollow tubular structure and is externally threaded. The three optical fibers 21, 22, 23 are respectively provided with optical fiber connectors 25, 26, 27, the optical fiber connectors 25, 26, 27 are provided with internal threads, the optical fiber connectors 25, 26, 27 are fixedly connected with the fastening screws 46 in a threaded manner, and laser fluorescence echo signals transmitted through the optical fibers 21, 22, 23 can be transmitted to the rear optical lens assembly 50 through the hollow part of the fastening screws 46. Three fastening screws 46 provided with the optical fibers 21, 22 and 23 are respectively inserted into the three slide rails 17, 18 and 19 and are tightened by fastening nuts 45 to realize the installation and positioning of the optical fibers 21, 22 and 23 on the slide rails 17, 18 and 19.

In this embodiment, three slide rails 17, 18, 19 preferably penetrate the front panel 12 of the housing to facilitate the assembly of the fastening assembly 43 on the slide rails 17, 18, 19. Since the sliding rails 17, 18, and 19 form light transmission holes, in order to prevent stray light outside the housing 10 from entering the interior of the housing 10 through the sliding rails 17, 18, and 19, and thus having a large influence on the optical signal collection of the optical element enclosed in the interior of the housing 10, the present embodiment preferably mounts a light shielding plate 44 on the fastening screw 46, as shown in fig. 3. The light shielding plate 44 is located inside the front panel 12 of the housing to shield the light holes formed by the slide rails 17, 18, 19 from light.

As a preferred embodiment, the shutter disk 44 is preferably designed as a disk of larger dimensions. When the chopping height of the near-field signal of the laser radar needs to be modulated, the fastening nuts 45 are unscrewed, and the positions of the fastening screws 46 in the slide rails 17, 18 and 19 are adjusted, so that the positions of the optical fibers 21, 22 and 23 relative to the chopping disk 40 are adjusted. During the process of adjusting the fastening screw 46, the light shielding plate 44 moves along with the fastening screw 46 to shield other light transmitting areas on the slide rails 17, 18, 19 except the fastening screw 46 to block the external stray light. After the optical fibers 21, 22, 23 are adjusted in position, the fastening nuts 45 are tightened to position the optical fibers 21, 22, 23 on the slide rails 17, 18, 19.

In the present embodiment, three optical fibers 21, 22, 23 are used to conduct three directions of laser fluorescence echo signals collected via the telescope of the laser radar. The optical fiber 21 is used for conducting laser fluorescence echo signals in the vertical direction; the optical fiber 22 is used for conducting laser fluorescence echo signals in the east direction; the optical fiber 23 is used for transmitting the laser fluorescence echo signal in the north direction. A photoelectric sensor 24 is also disposed on the front panel 12 of the housing 10, and as shown in fig. 1, the photoelectric sensor is preferably arranged in a circle with three optical fibers 21, 22, 23 to cooperate with the chopper disk 40 to generate a timing control signal as a time reference to coordinate the timing of the collection of the outgoing light and the echo signal of the laser.

Enclosed in the housing 10 is a chopper disk 40 and an optical lens assembly 50, as shown in fig. 2. The chopper wheel 40 is preferably designed as a circular disk, which is located between the optical fibers 21, 22, 23 and the optical lens assembly 50 and has a plurality of light passing holes 41 formed therein. A plurality of light passing holes 41 are arranged circumferentially on the disk, and a light shielding plate 42 is formed between two adjacent light passing holes 41.

As a preferred embodiment, four light passing holes 41 may be formed in the chopper wheel 40, thereby forming four light-shielding plates 42. It is preferable to design the central angles of the four light passing holes 41 and the four light shielding plates 42 to be equal, that is, the four light passing holes 41 and the four light shielding plates 42 are alternately and uniformly distributed on the disk. Wherein, the light-passing hole 41 is used for passing optical signals; the light shielding plate 42 is used for blocking the optical fibers 21, 22 and 23 from conducting optical signals to the optical lens assembly 50, so that chopping of low-altitude echo saturation signals is realized.

In order to drive the chopping disk 40 to rotate, the present embodiment is further provided with a motor 55 disposed on the front panel 12 of the housing 10, as shown in fig. 1, and the body portion is preferably disposed on the outer side of the front panel 12, and the rotating shaft of the motor 55 penetrates through the front panel 12 and is coupled to the chopping disk 40 to drive the chopping disk 40 to rotate, so that the light passing hole 41 and the light shielding plate 42 of the chopping disk 40 alternately rotate through the light incident end face of the optical lens assembly 50 and the photosensitive surface of the photosensor 24. The chopping disk 40 can chop the three-direction optical signals transmitted by the optical fibers 21, 22, 23 to the optical lens assembly 50 during the high-speed rotation process, so as to reduce the influence of the low-altitude saturation signal on the acquisition of the high-altitude fluorescence echo signal by the photodetectors 31, 32, 33. When the light-passing hole 41 and the light shielding plate 42 of the chopping disk 40 alternately pass through the photosensitive surface of the photoelectric sensor 24, the photoelectric sensor 24 outputs a pulse signal as a time sequence control signal of the laser radar system, and the pulse signal is used as a time reference to coordinate the light-emitting and echo signal acquisition time sequence of the laser, so that chopping of a low-altitude echo saturation signal and acquisition and storage of a high-altitude wind measurement signal are realized.

As a preferred embodiment, when the chopping disk 40 is designed to be in a certain position, as shown in fig. 4, its four light-passing holes 41 are respectively aligned with the three optical lens assemblies 50 and the photoelectric sensor 24 one by one, and in the specific implementation, the delay of the pulse signal output by the photoelectric sensor 24 can be adjusted, so as to meet the modulation requirements of the laser radar on the low-altitude echo saturation signals at different chopping heights.

The specific modulation process of the chopping height is as follows: referring to fig. 4, assuming that the chopper wheel 40 rotates clockwise, the optical fiber splice 25 in the vertical direction is first locked to the slide rail 17 in the vertical direction with reference to the echo signal in the vertical direction. When the chopping edge 47 of the chopping disk shown in fig. 4 turns to the vertically oriented fiber stub 25, the vertical channel starts receiving signals from the chopping height. At this time, if the east-direction channel and the north-direction channel are to obtain the same chopping height, the chopping edge 48 is required to be just turned to the east-direction optical fiber connector 26 and the chopping edge 49 is required to be just turned to the north-direction optical fiber connector 27 while the chopping edge 47 is turned to the vertical-direction optical fiber connector 25, which requires precise adjustment of the positions of the east-direction optical fiber connector 26 and the north-direction optical fiber connector 27 on the slide rails 18 and 19 of the east-direction optical fiber connector and the north-direction optical fiber connector with respect to the echo signals received by the laser radar. If the chopping height of the east-oriented near-field echo signal is lower than that of the vertical-direction near-field echo signal, the east-oriented optical fiber connector 26 needs to adjust the position on the arc-shaped slide rail 18 in the counterclockwise direction until the chopping height of the east-oriented near-field echo signal is consistent with that of the vertical-direction near-field echo signal; if the chopping height of the east-direction near-field echo signal is higher than the chopping height of the vertical-direction near-field echo signal, the east-direction optical fiber connector 26 needs to be adjusted in position on the arc-shaped slide rail 18 in the clockwise direction until the chopping height of the east-direction near-field echo signal is consistent with the chopping height of the vertical-direction near-field echo signal. And modulating the consistency of the chopping height of the near-field echo signal in the north direction according to the method until the consistency of the chopping height of the near-field echo signal in the vertical direction is consistent with the chopping height of the near-field echo signal in the vertical direction. Therefore, consistency of the chopping heights of the near-field echo signals of the laser radar in the three directions is achieved.

In this embodiment, the optical lens assembly 50 is provided with three paths, and is packaged in the housing 10, and the layout position of the optical lens assembly is opposite to the layout position of the three optical fibers 21, 22, and 23 in the front-back direction, and is respectively used for performing processing such as collimation, convergence, and the like on the optical signals from the three directions transmitted by the three optical fibers 21, 22, and 23.

Specifically, as shown in fig. 2 and 5, a lens barrel 51 and optical lenses arranged in the lens barrel 51 are provided in each of the optical lens assemblies 50. The optical lenses include preferably a collimating lens 52, an interference filter 53 and a converging lens 54. The collimating lens 52 is disposed on the light incident end face side of the lens barrel 51, optically coupled to the optical fiber 21/22/23, and configured to receive and optically collimate the optical signal transmitted and output by the optical fiber 21/22/23 to form parallel light. In the present embodiment, the optical signal emitted through the optical fiber 21/22/23 is a generally planar divergent light source, and the specific installation position of the collimator lens 52 in the lens barrel 51 can be determined according to the focal length of the collimator lens 52 and the divergent angle of the fiber planar light source. As a preferred embodiment, the collimating lens 52 preferably adopts an aspheric collimating lens, such as an optical lens with model number ACL2520A, to better perform optical collimation on the planar divergent light source emitted from the optical fiber 21/22/23.

The interference filter 53 is preferably installed between the collimating lens 52 and the converging lens 54, and is used for filtering interference light from the collimated parallel light output by the collimating lens 52, and then conducting the filtered parallel light to the converging lens 54.

The converging lens 54 is installed on one side of the light exit end face of the lens barrel 51, and is used for converging the parallel light from which the interference light is filtered onto the photodetector 31/32/33 for performing photoelectric conversion processing. In a preferred embodiment, the converging lens 54 is preferably a plano-convex lens, such as an optical lens with a model number LA1422, to obtain better converging effect.

In the present embodiment, the photodetectors 31, 32, and 33 are arranged in three ways, and are mounted on the housing 10, for example, on the rear panel 13 of the housing 10, as shown in fig. 6, and are preferably located outside the rear panel 13, so that the heat generated by the photodetectors 31, 32, and 33 can be rapidly released to the outside. The three- way photodetectors 31, 32, and 33 are disposed on the rear panel 13 of the housing at positions opposite to the three-way optical lens assembly 50, and are respectively used for performing photoelectric conversion on the light signals emitted from three directions after the three-way optical lens assembly 50 is collimated, filtered, and converged.

As a preferred embodiment, the photodetectors 31, 32, 33 preferably employ a photomultiplier tube having a window protection lens 38 and a photosensitive surface 39, and as shown in fig. 5, the focusing lens 54 focuses the optical signal to the window protection lens 38 of the photomultiplier tube and then to the photosensitive surface 39 of the photomultiplier tube, so as to realize photoelectric conversion in a photon counting manner.

This embodiment can further install fin and radiator fan 34 on photomultiplier to be arranged in cooling down the photomultiplier of working process, make its work in the best temperature range all the time, guarantee then that photomultiplier's photoelectric conversion efficiency can not change, realize the high sensitivity to weak light signal and detect.

In order to improve the stability of the mounting and fixing of the photodetectors 31, 32, 33 and the heat sink fan 34 on the rear panel 13 of the housing, in this embodiment, preferably three fixing bottom plates 37 are mounted on the rear panel 13 of the housing 10, the photodetectors 31, 32, 33 and the heat sink fan 34 are mounted on the fixing bottom plates 37, and three light passing holes are formed in the rear panel 13 of the housing 10, and each of the photodetectors 31, 32, 33 is optically coupled with the converging lens 54 in the three-way optical lens assembly 50 through one light passing hole, respectively, so as to accurately detect the optical signals in three directions.

A control circuit is arranged in the laser radar, and a time sequence control circuit, a power supply control circuit, a data acquisition circuit and the like can be arranged in the control circuit. The time sequence control circuit is used for receiving pulse signals output by the photoelectric sensor 24, generating time sequence control signals and sending the time sequence control signals to the processor so as to coordinate the light emitting time sequence of the laser and the collection time sequence of echo signals. The power control circuit can be connected with the power input interface 35 of the motor 55 and the photodetectors 31, 32, 33 to control the power supply of the motor 55 and the photodetectors 31, 32, 33. The data acquisition circuit receives the electrical signals output by the photodetectors 31, 32, 33 through their signal output interfaces 36 to generate observation data. The observation data is combined with the existing inversion algorithm to invert the three-dimensional wind field in the atmosphere for monitoring the atmospheric environment.

The laser radar receiving device of the embodiment can effectively receive three-direction weak fluorescence echo signals of a middle-high atmospheric wind field, and can well meet the requirement of the laser radar for measuring the middle-high atmospheric omnidirectional wind field.

Of course, the above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, it is possible to make various modifications and decorations without departing from the principle of the present invention, and these modifications and decorations should be regarded as the protection scope of the present invention.

Claims (10)

1. A near-field signal modulation and three-direction fluorescence receiving device for a laser radar, comprising:

the shell comprises a front panel and a rear panel which are in relative position relation, three arc-shaped slide rails are arranged on the front panel, and a fastening component with adjustable tightness is respectively arranged on each slide rail;

the optical fiber comprises three optical fibers and is used for receiving laser fluorescence echo signals from three directions; each optical fiber is provided with an optical fiber connector, the three optical fibers are correspondingly assembled with the fastening components on the three slide rails through the respective optical fiber connectors, and the optical fibers slide and are locked on the slide rails through the fastening components;

the optical lens assembly comprises three paths, is packaged in the shell, is optically coupled with the three optical fibers in a one-to-one correspondence mode, and is used for respectively carrying out collimation and convergence processing on three paths of optical signals emitted by the three optical fibers;

the chopping disk is packaged in the shell and positioned between the optical fiber and the optical lens assembly, a plurality of light through holes distributed along the circumferential direction are formed in the chopping disk, and a light shielding plate is formed between every two adjacent light through holes;

the motor is arranged on the shell and is in shaft connection with the chopping disk and used for driving the chopping disk to rotate so that the light shielding plate and the light through hole alternately pass through the light incidence end face of the optical lens assembly;

and the photoelectric detector comprises three paths of optical lenses, is arranged on the rear panel of the shell, is optically coupled with the three paths of optical lens assemblies in a one-to-one correspondence mode, and is used for carrying out photoelectric conversion processing on optical signals output by the three paths of optical lens assemblies.

2. The near-field signal modulation and three-directional fluorescence receiving apparatus for lidar according to claim 1, further comprising:

a photoelectric sensor mounted on the front panel of the housing, the light blocking plate and the light passing hole alternately passing through a photosensitive surface of the photoelectric sensor when the chopper wheel rotates;

and the control circuit receives detection signals output by the photoelectric detector and the photoelectric sensor and controls the working state of the motor.

3. The near-field signal modulation and three-directional fluorescence receiving device for lidar of claim 2, wherein the photoelectric sensor and the three optical fibers are arranged circumferentially on a front panel of the housing.

4. The near-field signal modulation and three-directional fluorescence receiving apparatus for lidar according to claim 3, wherein the chopper plate is a circular plate on which four light passing holes and four light blocking plates are formed; the central angles of the four light through holes and the four light shielding plates are equal, and the four light through holes and the four light shielding plates are alternately and uniformly distributed on the disc; and in the rotation process of the chopping disk, the chopping disk is provided with positions at which four light through holes are respectively opposite to the photoelectric sensor and the three optical lens assemblies one by one.

5. The near-field signal modulation and three-directional fluorescence receiving device for lidar according to any one of claims 1 to 4, wherein the slide rail penetrates through a front panel of the housing, and a light shielding plate is mounted on the fastening assembly, and the light shielding plate shields the slide rail from other parts except the fastening assembly, so as to block ambient light from entering the housing through the slide rail.

6. The near-field signal modulation and three-directional fluorescence receiving device for lidar according to claim 5, wherein the fastening component comprises a fastening screw and a fastening nut; the fastening screw is in a hollow tubular shape, is inserted into the slide rail and is in threaded connection with the optical fiber connector of the optical fiber; the fastening nut is in threaded connection with the fastening screw and is used for screwing the fastening screw and fixing the fastening screw on the sliding rail.

7. The near-field signal modulation and three-directional fluorescence receiving apparatus for lidar according to any one of claims 1 to 4, wherein the optical lens assembly comprises:

a lens barrel having a light incident end surface and a light exit end surface in a relative positional relationship;

the collimating lens is arranged in the lens barrel, is positioned on one side of the light incidence end surface of the lens barrel and is used for optically coupling with the optical fiber;

the interference filter is arranged in the lens barrel, is positioned behind the collimating lens in the light transmission direction, and is used for filtering interference light in the collimated light emitted by the collimating lens;

and the converging lens is arranged in the lens barrel, is positioned on one side of the light emergent end surface of the lens barrel and is used for optically coupling with the photoelectric detector.

8. The near-field signal modulation and three-directional fluorescence receiving apparatus for lidar according to claim 7, wherein the collimating lens is an aspheric collimating lens.

9. The near-field signal modulation and three-directional fluorescence receiving device for lidar according to any one of claims 1 to 4, wherein the photodetector is a photomultiplier tube on which a heat sink and a heat radiation fan are mounted.

10. The near-field signal modulation and three-directional fluorescence receiving device for lidar according to claim 9, wherein the photodetector is installed outside a rear panel of the housing.

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