CN112327275A

CN112327275A - Laser radar

Info

Publication number: CN112327275A
Application number: CN202011071904.5A
Authority: CN
Inventors: 吴世祥; 申士林; 向少卿
Original assignee: Hesai Technology Co Ltd
Current assignee: Hesai Technology Co Ltd
Priority date: 2019-01-07
Filing date: 2019-01-07
Publication date: 2021-02-05
Anticipated expiration: 2039-01-07
Also published as: CN112327275B; WO2020143542A1; CN109814086B; CN109814086A

Abstract

The invention provides a laser radar which comprises a laser transmitting module, a light splitting module, a scanning module and a receiving module, wherein the laser transmitting module is used for transmitting a pulse laser beam; the light splitting module is used for splitting the pulse laser beam into N incident beams; the scanning module is used for reflecting the N incident beams to a three-dimensional space and receiving and reflecting the N echo beams reflected by the target to be measured; the receiving module is used for receiving and processing the N echo light beams; the laser radar of the invention utilizes the light splitting module, so that on the premise of meeting the scanning field of the laser radar, less than N light sources can be adopted, the cost of the laser radar is reduced, the signal-to-noise ratio of an optical channel is reduced, and the distance measurement capability of the laser radar is improved.

Description

Laser radar

Technical Field

The invention relates to the technical field of environment perception, in particular to a laser radar.

Background

In the automatic driving technology, an environment sensing system is a basic and crucial ring and is a guarantee for the safety and intelligence of an automatic driving automobile, and in an environment sensing sensor, a laser radar has incomparable advantages in the aspects of reliability, detection range, distance measurement precision and the like.

The vehicle-mounted laser radar is used as an important sensor for sensing surrounding information, and the field of view and the scanning precision are important parameters of the vehicle-mounted laser radar. For a horizontal field of view, the prior art usually enlarges the field angle by arranging an optical lens in front of the scanning device, or arranges a plurality of laser radars to splice the collected fields of view. The front lens group requires a complicated lens group to enlarge the field angle, and the enlarged field angle reduces the effective aperture in equal proportion, especially when the laser radar receives light, the laser radar is affected by external interference light, and thus the distance measuring capability of the laser radar is reduced. The solution of multiple lidar splices can add significantly to the overall cost. In addition, a scheme of splicing the collected view fields by using a plurality of laser emission units is adopted, but the problems of high cost, heat dissipation caused by the working of the plurality of laser emission units and large volume still exist.

The laser radar needs to satisfy the performances of small volume, high reliability, high imaging frame frequency, high resolution, long-range distance measurement and the like. The existing laser radar is difficult to balance between small volume and multiple performance parameters, how to reasonably arrange the internal space of the laser radar, and on the premise of meeting the design of a specific light path, the space utilization rate is improved, the structure is more compact, the heat dissipation performance is improved, and the improvement is still needed at present.

Disclosure of Invention

The invention solves the technical problems of high cost, large volume, long and short distance measurement and the like of the laser radar in the prior art.

In order to solve the above technical problem, an embodiment of the present invention provides a laser radar, including a laser emitting module, a light splitting module, a scanning module, and a receiving module, wherein:

the laser emission module is used for emitting a pulse laser beam;

the light splitting module is used for splitting the pulse laser beam into N incident beams and transmitting the N incident beams to the scanning module, wherein N is more than or equal to 2;

the scanning module is used for reflecting the N incident beams to a three-dimensional space and receiving and reflecting N echo beams of the N incident beams after the N incident beams are reflected by a target to be detected in the three-dimensional space;

the receiving module is used for receiving and processing the N echo light beams; the receiving module comprises a reflecting unit, a converging unit, an extinction component and a detecting unit which are arranged in sequence;

the reflection unit is used for reflecting the echo light beam reflected by the scanning module;

the convergence unit is used for converging the echo light beam reflected by the reflection unit;

the extinction component is arranged between the convergence unit and the detection unit;

the detection unit is used for receiving and processing the echo light beam converged by the convergence unit;

the supporting body is provided with a light-transmitting structure, and the light-transmitting structure is used for only passing the incident light beam and the echo light beam;

the light splitting module and the scanning module correspondingly form N sub-scanning view fields, and the N sub-scanning view fields are spliced through the view fields to form the total view field of the laser radar.

Optionally, the spectroscopy module comprises a spectroscopy element and a reflective element, wherein:

the light splitting element is used for splitting one part of the pulse laser beam into N-1 beams of the N incident light beams and transmitting and incidence the other part of the pulse laser beam to the reflecting element;

and the reflecting element is used for reflecting another part of the pulse laser beam to form one of the N incident beams.

Optionally, the light splitting element includes a first light splitting element and a second light splitting element, wherein:

the first light splitting element is used for reflecting one part of the pulse laser beams to the scanning module to form a first incident light beam and transmitting the other part of the pulse laser beams to form a first transmitted light beam;

the second light splitting element is used for reflecting one part of the first transmitted light beam to the scanning module to form a second incident light beam and transmitting the other part of the first transmitted light beam to form a second transmitted light beam;

the reflecting element is used for reflecting the second transmitted light beam to the scanning module to form a third incident light beam.

Optionally, the ratio of the light intensities of the first incident light beam, the second incident light beam and the third incident light beam is x: y: z, wherein y is ≧ x and y is ≧ z.

Optionally, the reflection unit is disposed on an optical path formed by the incident light beam incident from the light splitting module to the scanning module.

Optionally, the reflection unit has a light-transmitting portion for being penetrated to pass the incident light beam.

Optionally, the light-transmitting portion is a light-transmitting hole.

Optionally, the light-transmitting structure includes N groups of optical channels, each group of optical channels includes a first sub optical channel and a second sub optical channel, the first sub optical channel is communicated with the second sub optical channel, and the first sub optical channel and the second sub optical channel are arranged at an included angle;

the first sub-optical channel is used for passing the incident light beam and the echo light beam,

the second sub-optical channel is used for passing and transmitting the echo light beam to the detection unit.

Optionally, the support body has a first end and a second end, the first sub-optical channel communicates the first end and the second end, and the second sub-optical channel communicates the second end;

the reflection unit is arranged at the communication position of the first sub-optical channel and the second sub-optical channel;

the convergence unit is arranged in the second sub-optical channel.

Optionally, the second sub optical channels of each group of optical channels are parallel to each other, and the first sub optical channels of each group of optical channels are paths extending from the corresponding first ends to the corresponding second ends by a preset length in a preset direction, where the preset direction is a direction from the central point of the scanning module to the central point of the reflection unit.

Optionally, the first end portions of each set of said light channels intersect.

Optionally, the support further has a third end, and the second sub-optical channel is further connected to the third end; and/or the presence of a gas in the gas,

the first end is also provided with at least one supporting arm, and the supporting arm is used for fixing the scanning module.

Optionally, the laser emission module includes a collimation unit, and the collimation unit is configured to adjust the pulse laser beam into a parallel beam and to enter the light splitting module;

the support body still includes the collimated light passageway, the collimated light passageway is located one side of N second sub-optical channel, the collimated light passageway with the second sub-optical channel is parallel, the collimation unit set up in the collimated light passageway.

Optionally, the extinction component is an extinction cylinder, one end of the extinction cylinder is connected to the support, and an opening at the other end of the extinction cylinder faces the detection unit.

Optionally, the inner wall of the extinction cylinder is of a tapered multi-section stepped hole structure, the large-diameter end of the extinction cylinder is connected with the supporting body, and the outlet of the small-diameter end of the extinction cylinder faces the detection unit.

Optionally, the inner side wall of the extinction cylinder is provided with one or a combination of any of extinction threads, extinction rings and extinction materials.

Optionally, the material of the light extinction component is metal or plastic.

Optionally, the scanning module has a movable part, and a side of the movable part facing the light splitting module has a reflection surface for reflecting the incident light beam;

the other area of the side of the scanning module facing the light splitting module except the reflecting surface is defined as a first area, and at least part of the first area is plated with a light extinction material.

Optionally, the lidar further comprises a control module, wherein:

the control module is respectively connected with the laser emission module, the scanning module and the N detection units;

the control module is used for respectively controlling the laser emitting module to emit the pulse laser beam, controlling the rotation and/or swing of the movable part and controlling the detection unit to receive and process the echo light beam.

Optionally, the laser radar further comprises a housing and a bottom plate, an opening is formed in the bottom end of the housing, and the housing and the bottom plate are connected in a sealing manner to form an accommodating cavity;

the laser emission module, the scanning module, the control module and the support body are all accommodated in the accommodating cavity.

Optionally, the laser radar further includes a power supply module, and the power supply module is disposed in the accommodating cavity;

the shell is provided with a side wall, and the power supply module, the control module and the laser emission module are respectively arranged at the positions, close to the side wall, in the accommodating cavity.

Optionally, at least a partial region of the outer side of the housing is provided with heat dissipating teeth.

Optionally, the laser emission module comprises a light source and a fiber optic connection assembly, wherein:

the light source is used for emitting the pulse laser beam;

the optical fiber connecting component is coupled with the light source and used for transmitting the pulse laser beam.

Optionally, the laser emission module further includes a deflection unit, the deflection unit is disposed between the collimation unit and the light splitting module, and is configured to deflect the parallel light beam adjusted by the collimation unit, and to emit the deflected parallel light beam to the light splitting module.

Optionally, a hollow area is disposed on the side wall, the hollow area is opposite to the light exit side of the scanning module, and the laser radar further includes a front window, which covers the hollow area and is configured to transmit the incident light beam reflected by the scanning module and the echo light beam; and/or the presence of a gas in the gas,

the convergence unit comprises a filtering subunit and a convergence subunit, the filtering subunit is arranged in front of the convergence subunit along a transmission path of the echo light beam, the filtering subunit is used for transmitting the echo light beam reflected by the reflection unit and filtering out optical signals outside a preset wavelength range, and the convergence subunit is used for converging the echo light beam transmitted by the filtering subunit; and/or the presence of a gas in the gas,

the detection unit comprises a receiving circuit board, at least one detector is arranged on the receiving circuit board, and the detector is arranged on one side face, facing the convergence unit, of the receiving circuit board.

By adopting the technical scheme, the laser radar has the following beneficial effects:

in the above scheme, laser radar utilizes the beam splitting module to carry out beam splitting processing to pulse laser beam, so can be adopting less than N light sources, only adopt under the condition of a light source even, still satisfy laser radar to the demand of scanning visual field simultaneously, consequently can effectively reduce laser radar's cost and reduce laser radar's volume. And the light source is a part with relatively more heat dissipation in the laser radar, and the reduction of the number of the light sources can also reduce the heat production in the laser radar, thereby improving the working efficiency and reliability of the laser radar.

Furthermore, the laser radar in the embodiment of the invention can also be provided with a support body, and because the light-transmitting structure is arranged in the support body to transmit the light beams, and the position and the size of the light-transmitting structure can ensure that only the incident light beams and the echo light beams in the corresponding direction of the preset sub-scanning view field pass through, the interference of the ambient light can be reduced.

Furthermore, the light-transmitting structure and the light path of the support body meet the compact design, the first sub-light channels of the N groups of light channels converge towards the scanning module and extend for a preset length, and the light channels are arranged in such a way, so that the space occupied by the light path for the support body is reduced, the utilization rate of the internal space of the support body is improved, the height of the support body is reduced, and the overall height of the laser radar can be reduced.

Furthermore, in the embodiment of the present invention, an extinction cylinder is disposed between the convergence unit and the detection unit, and the extinction cylinder can consume an unexpected light beam, so that interference of ambient stray light and crosstalk between N echo light beams can be reduced, and a signal-to-noise ratio of each optical channel is improved, thereby improving a distance measurement capability of the entire laser radar.

Furthermore, the inner wall of the extinction cylinder is set to be in a tapered multi-section stepped hole structure, the large-diameter end of the extinction cylinder is connected with the supporting body, and the outlet of the small-diameter end of the extinction cylinder faces the detection unit, so that light of a non-target light channel can be consumed in continuous reflection, and the efficiency of eliminating crosstalk between stray light and N echo light beams can be improved.

Furthermore, the inner side wall of the extinction cylinder is provided with one or the combination of any more of extinction threads, extinction rings and extinction materials, so that the effect of eliminating stray light can be further improved.

Furthermore, the laser radar in the embodiment of the invention adopts plastic as the material of the extinction cylinder, so that an electromagnetic interference path can be effectively cut off, the electromagnetic compatibility of a laser radar system is improved, and the normal work of the laser radar in an electromagnetic environment can be ensured.

Furthermore, the laser radar in the embodiment of the invention can share one or more light sources, a plurality of laser emission sub-modules do not need to be arranged to correspond to a plurality of receiving sub-modules, the space actually occupied by the laser emission module is saved, the positions of the laser emission modules can be flexibly arranged by utilizing the optical fiber connecting assembly, and the heat dissipation in the laser radar is facilitated.

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 description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a block diagram of a lidar according to one embodiment of the present invention;

FIG. 2 is a perspective view of a portion of a lidar according to one embodiment of the present invention;

FIG. 3 is a perspective view of the internal structure of a lidar according to one embodiment of the present invention;

FIG. 4 is a perspective view of a support body according to one embodiment of the present invention;

FIG. 5 is a perspective view of the support body of FIG. 4 from another perspective;

FIG. 6 is a perspective view of an extinction cartridge in accordance with one embodiment of the invention;

FIG. 7 is a perspective view of the extinction cylinder of FIG. 6 from another perspective;

FIG. 8 is a schematic cross-sectional view of the matting barrel of FIG. 6;

FIG. 9 is a cross-sectional view of a portion of a lidar in accordance with one embodiment of the present invention;

fig. 10 is a schematic diagram of a transmitting light path of the lidar according to one embodiment of the present invention.

The following is a supplementary description of the drawings:

10-a laser emission module; 101-a light source; 102-a fiber optic connection assembly; 103-a collimating unit; 104-a deflection unit;

20-a light splitting module; 21-a light splitting element; 211-a first light splitting element; 212-a second light splitting element; 22-a reflective element; 23-a fixed seat;

30-a scanning module; 301-a movable part; 302-a first region;

40-a receiving module; 400-a receiving submodule; 401-a reflection unit; 402-a convergence unit; 4021-a filtration subunit; 4022-convergence subunit; 403-a detection unit; 4031-a receiving circuit board;

50-a support; 500-optical channel; 501-a first sub-optical channel; 502-a second sub-optical channel; 5021-a joint; 503-collimated light channel; 51-a first end; 52-second end, 53-third end; 54-a support arm;

60-a delustering cylinder; 601-a connecting part;

70-a control module;

1001-pulsed laser beam; 1002-a first incident beam; 1003-first transmitted beam; 1004 — a second incident beam; 1005-a second transmitted beam; 1006 — third incident beam.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the invention. In the description of the present invention, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred 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, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein.

To solve the problems of the laser radar in the prior art, such as high cost and large size, fig. 1 shows a block diagram of the laser radar according to an embodiment of the present invention, and the technical solution of the present invention is described below with reference to fig. 1. As shown in fig. 1, an embodiment of the present invention provides a laser radar, which may include a laser emitting module 10, a light splitting module 20, a scanning module 30, and a receiving module 40, where:

the laser emitting module 10 is configured to emit a pulse laser beam;

the light splitting module 20 is configured to split the pulse laser beam into N incident light beams and transmit the N incident light beams to the scanning module 30, where N is greater than or equal to 2;

the scanning module 30 is configured to reflect the N incident light beams to a three-dimensional space, and to receive and reflect N echo light beams of the N incident light beams reflected by a target to be measured in the three-dimensional space;

the receiving module 40 is configured to receive and process the N echo light beams;

the spectroscopy module 20 and the scanning module 30 may correspondingly form N sub-scanning fields, and the N sub-scanning fields may be spliced to form a total field of the lidar.

Specifically, when the laser radar is in a working state, the laser emitting module 10 emits a pulse laser beam and transmits the pulse laser beam to the light splitting module 20 or directly enters the light splitting module 20, the light splitting module 20 splits the pulse laser beam into N incident beams and reflects the N incident beams to the scanning module 30, the scanning module 30 reflects the N received incident beams to a three-dimensional space for detection, and a target to be detected in the three-dimensional space is reflected to form N echo beams; the scanning module 30 may receive the N echo beams and reflect the N echo beams to the receiving module 40; the receiving module 40 receives and processes the N echo beams to obtain the required environmental sensing data. By applying the scheme, the pulse laser beam is split into N incident beams by the light splitting module and is emitted into the target space at different field angles, the scanning of a plurality of sub-scanning field fields can be directly realized, the scanning mode is simple, the system complexity is low, the integration is convenient, and the cost and the complexity of the laser radar can be reduced.

In addition, when the laser radar is in an operating state, the spectroscopy module 20 and the scanning module 30 form N corresponding transmitting optical paths, the scanning module 30 forms N corresponding receiving optical paths with the N receiving modules 40, the N transmitting optical paths and the N receiving optical paths correspond one to one, and the N transmitting optical paths and the N receiving optical paths may be partially coaxial.

In addition, because the light splitting module performs light splitting processing on the pulse laser beam, in the actual use process, the transmitting module of the laser radar can be used under the condition that less than N light sources are adopted, even only one light source is adopted, the number of the light sources of the laser transmitting module does not form the limitation of the invention, and a person skilled in the art can flexibly select the light sources according to the requirement of scanning density, the heat dissipation problem and the size requirement of the laser radar and the size limitation of the scanning module.

It should be noted that, a person skilled in the art may set the size of N according to actual needs, for example, the person skilled in the art may set an appropriate value of N by balancing the requirement of the size of the field of view and the requirement of the volume of the laser radar, as long as N is a positive integer not less than 2. In a specific application, for example, a technician may set N to 3, may also set N to 5, and may also set N to 6, where the specific value of N does not set any limit to the scope of the present invention. In order to make the technical scheme of the invention better understood and realized by those skilled in the art, N-3 is taken as an example to illustrate the technical scheme of the invention.

In some embodiments, the receiving module may include N sets of receiving sub-modules, and any one set of receiving sub-modules includes a reflecting unit, a converging unit, and a detecting unit, which are sequentially disposed. For example, as shown in fig. 1 and fig. 2, the receiving module 40 may include three sets of receiving sub-modules 400, and any one of the receiving sub-modules 400 includes a reflecting unit 401, a converging unit 402, and a detecting unit 403, which are sequentially disposed.

The reflection unit 401 is located between the spectroscopy module 20 and the scanning module 30, and reflects the echo beam;

the converging unit 402 is configured to converge the echo light beam reflected by the reflecting unit 401;

the detecting unit 403 is configured to receive and process the echo light beam converged by the converging unit 402 to obtain distance information of the obstacle.

In some embodiments, the reflection unit is disposed on an optical path formed by the incident light beam incident from the light splitting module to the scanning module. The reflection unit may be further configured to transmit the incident light beam. Specifically, the reflection unit is provided with a light-transmitting portion for being penetrated to pass the incident light beam. The light-transmitting part can be a light-transmitting hole or a light-transmitting area, and in practical application, the light-transmitting area can be a transparent glass flat sheet or a transparent plastic flat sheet or a lens.

In a possible embodiment, as shown in fig. 2 and 3, the reflecting unit 401 is a mirror with a light-transmitting hole, i.e. a pinhole mirror. The size of the light hole may be 1.0-2.0 times the incident beam diameter. The preparation process of the reflection unit 401 may be as follows: firstly, a light-transmitting hole with a diameter equivalent to that of the incident beam and a little larger than that of the incident beam is punched on a ground and polished glass substrate, and then a total reflection film is plated on one surface of the substrate.

In another possible embodiment, the reflection unit 401 is a mirror with a light transmission region, and can be prepared by first grinding and polishing a substrate, plating an antireflection film on one surface of the substrate, plating an antireflection film in a predetermined light transmission region on the other surface of the substrate, and plating a total reflection film in a region outside the predetermined light transmission region, wherein the predetermined light transmission region is a circular hole, and the diameter of the predetermined light transmission region is greater than or equal to the diameter of the incident light beam.

In other possible embodiments, the reflection unit 401 may also implement this function by using a polarization splitting sheet.

In some embodiments, the incident light beam passing through the light-transmitting portion is coaxial with the echo light beam reflected by the scanning module 30.

In some embodiments, the above-mentioned light splitting module comprises a light splitting element and a reflecting element, wherein:

the beam splitting element is used for splitting one part of the pulse laser beam into N-1 beams of the N incident beams and transmitting and irradiating the other part of the pulse laser beam to the reflecting element;

the reflecting element is used for reflecting another part of the pulse laser beam to form one of the N incident beams.

Specifically, the spectral module comprises N-1 spectral elements and a reflecting element, wherein the N-1 spectral elements and the reflecting element are arranged at intervals along a first direction;

the N-1 light splitting elements divide the pulse laser beam into N-1 incident light beams, and the incident light beams are incident on the scanning module to correspondingly form N-1 sub-scanning view fields;

the pulse laser beam which passes through the (N-1) th light splitting element is reflected by the reflecting element to form an Nth incident light beam, and the Nth incident light beam is incident on the scanning module to correspondingly form a sub-scanning view field; the horizontal N sub-scanning fields are arranged in parallel, and a compact optical structure is realized while the horizontal field is enlarged by field splicing.

In some embodiments, the light splitting element 21 may be an aperture mirror, a half-mirror, a polarizing beam splitter, or a beam splitter using a coating method. Further, the splitting ratio of the single splitting element 21 may be, but is not limited to, a transmittance of 10% to 50% and a reflectance of 50% to 90%.

In some embodiments, as shown in fig. 2 and fig. 3, the light splitting element 21 includes a first light splitting element 211 and a second light splitting element 212, wherein:

the first beam splitter 211 is configured to reflect a portion of the pulsed laser beam to the scanning module to form a first incident beam, and transmit another portion of the pulsed laser beam to form a first transmitted beam;

the second beam splitter 212 is configured to reflect a portion of the first transmitted beam to the scan module to form a second incident beam, and transmit another portion of the first transmitted beam to form a second transmitted beam;

the reflective element 22 is configured to reflect the second transmitted light beam to the scanning module to form a third incident light beam.

Specifically, the first light splitting element 211 is configured to receive the pulse laser beam, form a first incident beam and a first transmitted beam, and inject the first incident beam into the scanning module 30 to correspondingly form a first sub-scanning field;

the second beam splitter 212 is configured to receive the first transmitted light beam, form a second incident light beam and a second transmitted light beam, and inject the second incident light beam into the scanning module 30 to correspondingly form a second sub-scanning field;

the reflective element 22 is configured to receive the second transmitted light beam, reflect the second transmitted light beam to form a third incident light beam, and enter the scanning module 30 to correspondingly form a third sub-scanning field. In a specific implementation, each sub-scanning field may be set to 20 °, and then after the first sub-scanning field, the second sub-scanning field, and the third sub-scanning field are spliced, the horizontal total field of view of the laser radar may reach 60 °.

In some embodiments, the ratio of the intensity of the first incident light beam, the intensity of the second incident light beam, and the intensity of the third incident light beam is x: y: z, wherein y is ≧ x and y is ≧ z. In the specific implementation, the light intensity ratio x of the three is as follows: y: the value of z can be 1:2:1 or 2:5:2, and the like, and the light intensity ratio of the three can be arbitrarily taken according to the actual application scene and the system performance requirement.

In some embodiments, as shown in fig. 3 and 9, the splitter module 20 further includes a fixing base 23 for mounting the splitter element 21 and the reflecting element 22. Specifically, the first light splitting element 211, the second light splitting element 212, and the reflection element 22 are sequentially disposed on the fixing base 23 at intervals according to a predetermined splitting optical path. The first light splitting element 211, the second light splitting element 212, and the reflecting element 22 are located on the same straight line.

Specifically, as to the operation process of the optical splitting module, as described in detail with reference to fig. 10, when the laser radar is in an operating state, the pulsed laser beam 1001 is emitted to the first optical splitting element 211, a part of the pulsed laser beam is reflected by the first optical splitting element 211, a part of the pulsed laser beam is transmitted by the first optical splitting element 211, and a first incident beam 1002 and a first transmitted beam 1003 are respectively formed, and then the first incident beam 1002 is incident to the scanning module 30 and is reflected by the scanning module 30 to form a first emission optical path.

In addition, the first transmitted beam 1003 enters the second beam splitting element 212, a part of the first transmitted beam is reflected by the second beam splitting element 212, and a part of the first transmitted beam is transmitted by the second beam splitting element 212 to form a second incident beam 1004 and a second transmitted beam 1005, respectively, and the second incident beam 1004 also enters the scanning module 30 and is reflected by the scanning module 30 to form a second emission light path;

the second transmitted beam 1005 is incident on the reflective element 22, and then can be reflected by the reflective element 22 to form a third incident beam 1006, and the third incident beam 1006 is also incident on the scanning module 30 and then reflected by the scanning module 30 to form a third emission light path.

In an embodiment of the present invention, the laser radar may further include a supporting body, and the supporting body may be specifically disposed between the light splitting module and the detection unit, that is, the supporting body may be located on an incident light path formed by the incident light beam passing through, and the echo light beam is coaxial with the incident light beam, and correspondingly, the supporting body is also located on an echo light path formed by the echo light beam passing through. And the support body is provided with a light-transmitting structure, and the size and the position of the light-transmitting structure are related to the size and the position of the echo light beam when the echo light beam is incident on the support body, so that the light-transmitting structure can ensure that only the light beam in the same direction as the incident light beam and the echo light beam passes through as much as possible, thereby reducing the interference of stray light, and improving the distance measurement capability and the distance measurement accuracy of the laser radar. It should be noted that it is not excluded that ambient stray light having a direction consistent with the direction of the echo light beam enters the light-transmitting structure.

For example, as shown in fig. 3, 4 and 9, the laser radar includes a support 50, the support 50 is disposed between the spectroscopy module 20 and the detection unit 403, and the support 50 is provided with a light-transmitting structure, which is configured to pass only the incident light beam and the echo light beam, without excluding the entrance of ambient light in different directions.

In some embodiments, as shown in fig. 4 and 5, the light-transmitting structure includes three sets of light channels 500, each set of the light channels 500 includes a first sub-light channel 501 and a second sub-light channel 502, the first sub-light channel 501 is communicated with the second sub-light channel 502, and the first sub-light channel 501 and the second sub-light channel 502 are disposed at an included angle.

Moreover, the incident light beam can be incident to the scanning module 30 through the first sub-optical channel 501, when the light beam is reflected back by the target to be measured, the echo light beam can also be incident through the first optical channel 501, and after being transmitted through the first optical channel 501, the echo light beam is incident to the reflection element, then is reflected by the emission element, enters the second sub-optical channel 502, and finally is transmitted to the detection unit 403. The position and the size of any group of optical channels can ensure that only the incident light beams and the echo light beams corresponding to the group of optical channels can pass through, and the interference of ambient light is prevented.

In some embodiments, the support body has a first end and a second end, the first sub-optical channel communicates the first end and the second end, and the second sub-optical channel connects the second end; the reflection unit is arranged at the communication position of the first sub-optical channel and the second sub-optical channel; the convergence unit is arranged in the second sub-optical channel.

The support body is also provided with a third end, and the second sub-optical channel is also communicated to the third end. It should be noted that the second sub optical channel does not necessarily have to penetrate through to the third end, and if the second sub optical channel may be in the form of a blind hole, the detection unit may be disposed at a bottom end in the second sub optical channel.

In some embodiments, as shown in fig. 4 and 5, the supporting body 50 has a first end 51, a second end 52 and a third end 53, the first sub-optical channel 501 communicates with the first end 51 and the second end 52, and the second sub-optical channel 502 communicates with the second end 52 and the third end 53. The reflection unit 401 is disposed at a communication position between the first sub optical channel 501 and the second sub optical channel 502, and the N reflection units 401 of the receiving module 40 face the scanning module 30. The converging unit 402 is disposed in the second sub-optical channel 502.

The reflection unit 401 and the convergence unit 402 are disposed at predetermined angles with respect to their corresponding light channels 500, respectively. With regard to the setting of the predetermined angle, in one embodiment, the N converging units 402 of the N groups of receiving sub-modules 400 may be all arranged perpendicular to the second sub-optical channel 502, that is, the predetermined angle is set to 90 °. In another embodiment, the reflection units 401 may be mounted at the second end 52 of the supporting body 50, and the N reflection units 401 of the N groups of receiving sub-modules 400 form an included angle of 45 ° with the bottom surface of the supporting body 50, that is, the predetermined angle is set to be 45 °. The reflection surfaces of the N reflection units 401 face the scan module 30.

As shown in fig. 3, the receiving module 40 has three reflecting units 401, and the three reflecting units 401 respectively correspond to the first light splitting element 211, the second light splitting element 212 and the reflecting element 22 one by one, so as to ensure that the three incident light beams generated by the light splitting module 20 can penetrate through the light-transmitting portions (i.e., light-transmitting holes) of the reflecting units 401 and enter the scanning module 30.

In a possible embodiment, the first sub-optical channels of the N groups of optical channels are parallel to each other, the second sub-optical channels of the N groups of optical channels are also parallel to each other, and the exit position of the first sub-optical channel near the scanning module side is provided with a deflection prism to deflect an incident light beam to the scanning module, while ensuring that the echo light beams corresponding to the respective groups of optical channels return to the respective optical channels through the deflection prism.

In a possible embodiment, the second sub optical channels of each group of the optical channels are parallel to each other, and the first sub optical channel of each group of the optical channels is a path extending from the corresponding first end to the corresponding second end by a predetermined length in a predetermined direction, where the predetermined direction is a direction from a center point of the scanning module to a center point of the reflection unit. That is, the first sub-optical channels of each group respectively penetrate through the first end, and the preset directions of the first sub-optical channels of each group are all directed to the reflection side of the scanning module by the reflection unit.

In some embodiments, the first end portions of each set of said light channels intersect.

Specifically, referring to fig. 4 and 5, the second sub-optical channels 502 of the three sets of optical channels 500 are parallel to each other, and the first sub-optical channels 501 of the three sets of optical channels 500 converge toward the scanning module 30 and extend by a predetermined length; the first sub-optical channels 501 of the N groups of optical channels 500 intersect toward one end portion of the scan module 30. By arranging the optical channel 500 in this way, the space occupied by the optical path in the support body 50 can be reduced, the utilization rate of the internal space of the support body 50 is improved, and the height of the support body 50 is reduced, so that the overall height of the laser radar can be further reduced.

In some embodiments, the first sub-optical channel and the second sub-optical channel are both hollow through holes, and air or other light-transmitting media are filled in the first sub-optical channel and the second sub-optical channel.

In some embodiments, the first end of the supporting body is further provided with at least one supporting arm, and the supporting arm is connected with the scanning module and used for fixing the scanning module.

Specifically, as shown in fig. 4 and 5, two supporting arms 54 are disposed at an interval on the first end 51 of the supporting body 50, the supporting arms 54 are connected to the scanning module 30, and the supporting arms 54 are disposed at an angle, such as 45 °, to the third end 53 of the supporting body 50, respectively, so as to ensure that the reflection side of the scanning module 30 can receive the incident light beam and the echo light beam. In a possible embodiment, the supporting arm 54 may be formed integrally with the supporting body 50.

In some embodiments, the receiving module further includes an extinction component disposed between the converging unit and the detecting unit for preventing the N echo beams from crosstalk with each other.

In some embodiments, the extinction member is an extinction cylinder 60, and as shown in fig. 9, one end of the extinction cylinder 60 is connected to the support 50, and the other end of the extinction cylinder 60 is opened toward the detection unit 403; the extinction cylinder 60 is in communication with the second sub optical channel 502. The extinction cylinder 60 is used to consume stray light in the continuous reflection.

In some embodiments, as shown in fig. 7 and fig. 9, the inner wall of the extinction tube 60 has a tapered multi-step hole structure, the large diameter end of the extinction tube 60 is connected to the supporting body 50, and the outlet of the small diameter end of the extinction tube 60 faces the detection unit 403. The number of the sections of the stepped hole is more than or equal to 2. The multi-section stepped hole structure can form a plurality of reflection steps, increases the reflection area, can reflect stray light for multiple times or multiple stages to consume crosstalk light, and improves extinction efficiency. Specifically, the number of stages of the stepped hole is determined according to the expected extinction ratio, the space of assembly, and the volume of the entire laser radar. Preferably, as shown in fig. 8, the number of the stepped hole is 11.

In some embodiments, a connection portion 601 is disposed on an outer wall of the large-diameter end of the extinction cylinder 60, a coupling portion 5021 is disposed at an end of the second sub-optical channel 502 close to the detection unit 403, and the connection portion 601 is connected to the coupling portion 5021 in a matching manner. Specifically, the large-diameter end of the matting tube 60 is fixed to the support 50 by a screw connection, a bayonet connection, a plug-in fixation, an adhesion, or the like. For example, as shown in fig. 5, 6, and 9, the connection portion 601 is a male screw, the coupling portion 5021 is a female screw that engages with the male screw, and the matting tube 60 is screwed to the support 50.

In another possible embodiment, the inner wall of the extinction cylinder 60 has a tapered structure, and the contour dimension of the inner wall of the extinction cylinder 60 near the end of the detection unit 403 is smaller than the contour dimension of the inner wall of the extinction cylinder 60 near the end of the convergence unit 402. Preferably, the cross section of the matting tube 60 is circular.

In a possible embodiment, the entire matting tube 60 may have a cylindrical structure, a square-funnel structure, a tapered structure, a funnel structure, or the like.

In some embodiments, the inner side wall of the extinction cylinder 60 is provided with one or a combination of any of extinction threads, extinction rings and extinction materials, so as to further increase the effect of eliminating stray light. In addition, the internal surface area of the extinction cylinder is increased by utilizing the multi-section stepped hole structure, and the extinction material coated on the internal surface is matched to absorb stray light, so that the extinction efficiency is further improved.

In some embodiments, the material of the matting barrel 60 is metal or plastic. Preferably, the material of the matting tube 60 is plastic. In order to eliminate stray light and prevent crosstalk between echo beams of different optical channels, the end of the extinction cylinder 60 close to the detection unit 403 should be as close to the detection unit 403 as possible. When the extinction cylinder 60 is made of metal, a parasitic capacitance is formed between the extinction cylinder 60 and the detection unit 403, so that electromagnetic interference is caused to the detection unit 403. In addition, since the photodetector needs to be set at a higher bias voltage during operation, the bias voltage may cause air breakdown between the detection unit 403 and the extinction cylinder 60 in some extreme cases. Therefore, the extinction barrel 60 made of plastic can effectively cut off an electromagnetic interference path and improve the electromagnetic compatibility of the laser radar system, so that the laser radar can normally work in an electromagnetic environment.

In some embodiments, the light extinction member may be integrally formed with the support body.

In some embodiments, the scanning module 30 may be an electrostatic galvanometer, an electromagnetic galvanometer, a piezoelectric galvanometer, an electrothermal galvanometer, or the like. The scanning module 30 can also change the direction of the pulse laser beam reflected to the three-dimensional space by rotating or swinging, thereby scanning the target in the three-dimensional space.

As shown in fig. 2 and 3, the scanning module 30 has a movable portion 301, and a side of the movable portion 301 facing the spectroscopic module 20 has a reflection surface for reflecting a light beam; the other area of the side of the scanning module 30 facing the spectroscopy module 20 except the reflection surface is defined as a first area 302, and at least a part of the first area 302 is coated with a light extinction material. Preferably, the first region 302 is entirely plated with a matte material. The scanning module 30 further includes a driving mechanism for driving the movable portion 301 to rotate or swing periodically.

In some embodiments, as shown in fig. 1, the lidar further includes a control module 70, the control module 70 is respectively connected to the laser emitting module 10, the scanning module 30 and N of the detecting units 403, and the control module 70 is configured to respectively control the laser emitting module 10 to emit the pulse laser beam, control the rotation or swing of the movable portion 301, and control the detecting units 403 to receive and process the echo beam. Specifically, the control module 70 controls the rotation or oscillation of the movable portion 301 through the driving mechanism.

In some embodiments, the control module 70 is a control circuit board.

In some embodiments, the lidar further includes a housing and a bottom plate, the bottom end of the housing has an opening, the housing and the bottom plate are hermetically connected to form an accommodating cavity, and the laser emitting module 10, the scanning module 30, the control module 70 and the supporting body 50 are all accommodated in the accommodating cavity.

In a possible embodiment, the scanning module 30 is located in the upper space of the accommodating chamber, and the scanning module 30 is fixedly mounted on the top wall of the housing without the support arm 54 of the support 50.

In some embodiments, the laser radar further includes a power module disposed in the accommodating cavity; the housing has a side wall, and the power module, the control module 70 and the laser emitting module 10 are respectively disposed in the accommodating cavity at positions close to the side wall, so that heat generated by the power module, the control module 70 and the laser emitting module 10 in the working process can be conducted to the outside through the housing.

In some embodiments, the housing is a box-shaped structure with an open bottom end, the side walls of the housing include a first side wall, a second side wall, a third side wall and a fourth side wall, the laser emitting module 10 is disposed near or attached to an inner surface of the first side wall, the power module is disposed near or attached to an inner surface of the second side wall, the control module 70 is disposed near or attached to an inner surface of the third side wall, and the receiving unit is also disposed near an inner surface side of the second side wall. In addition, heat conducting gel, cooling gas or cooling device may be disposed around the laser emitting module 10 to further enhance the heat dissipation effect.

In some embodiments, at least a partial region of the outer side of the housing is provided with heat dissipating teeth. In a possible embodiment, the first side wall, the second side wall, and the third side wall are each provided with a plurality of the heat dissipation teeth, and the number and distribution of the heat dissipation teeth may be flexibly arranged according to the heat dissipation requirement of the laser radar and the appearance requirement, such as parallel and spaced distribution, or staggered distribution, involute distribution, annular distribution, and the like.

In some embodiments, a hollow area is disposed on the sidewall, the hollow area is opposite to the light emitting side of the scanning module 30, and the laser radar further includes a front window covering the hollow area, and configured to transmit the incident light beam reflected by the scanning module 30 and transmit the echo light beam. Specifically, the hollow area is located on the fourth sidewall.

In some embodiments, the front window may be a laser window mirror, which is disposed to protect the scanning module 30 from splashes and other hazards in the workplace, and the laser window mirror is usually made of a material that is highly transparent to laser light with a specific wavelength, and is coated with an anti-reflection film to reduce loss due to reflection.

In some embodiments, as shown in fig. 1, the laser emitting module 10 includes a light source 101, a fiber connection assembly 102, and a collimating unit 103, where the light source 101 is configured to emit the pulsed laser beam;

the optical fiber connection assembly 102 is coupled to the light source 101, and is configured to transmit the pulse laser beam emitted by the light source 101 to the collimating unit 103;

the collimating unit 103 is configured to adjust the pulse laser beam into a parallel beam and to irradiate the beam splitting module 20.

In some embodiments, the laser emitting module 10 has M light sources 101, where M ≧ 1, and when the laser emitting module 10 has a plurality of light sources 101, the plurality of light sources 101 may be spaced apart by an optical fiber in a vertical field of view of the lidar. In a possible embodiment, the laser emitting module 10 may employ less than N light sources 101 (i.e., M < N), or even only one light source 101 (i.e., M ═ 1).

In some embodiments, the light source 101 may be a laser, such as a semiconductor laser, a wavelength tunable solid-state laser, or a fiber laser, and different types of lasers may emit laser beams having different wavelengths.

In some embodiments, the collimating unit 103 is a collimating lens, and the fiber connecting assembly 102 includes an optical fiber, and the collimating lens has a focal point at the position of the exit end face of the optical fiber and has a function of converting the light emitted from the optical fiber bundle into a parallel light beam. The collimating lens may be composed of one or more lenses.

In some embodiments, the end face of the end of the optical fiber is cut to form an angle of 45 degrees with the extending direction of the optical fiber, and the end face is coated with a high-reflection medium coating to provide a mirror surface, so that the light beam in the optical fiber is reflected by the end face and enters the collimating unit 103, and the light beam is collimated by the collimating unit 103 and then enters the spectral module 20.

In some embodiments, the support further includes a collimating light channel, the collimating light channel is located at one side of the N second sub-light channels, and the collimating unit is disposed in the collimating light channel.

In a possible embodiment, as shown in fig. 4 and 5, the collimating light channel 503 is parallel to the second sub-light channel 502, and the collimating unit 103 is perpendicular to the collimating light channel 503.

In some embodiments, the laser emitting module 10 further includes a deflecting unit 104, and the deflecting unit 104 is disposed between the collimating unit 103 and the light splitting module 20, and is configured to deflect the parallel light beams adjusted by the collimating unit 103 and emit the parallel light beams to the light splitting module 20.

In a possible embodiment, the deflecting unit 104 is located at one end of the collimating light channel 503 close to the light splitting module 20, and the deflecting unit 104 and the light splitting element 21 of the light splitting module 20 are located on the same straight line, as shown in fig. 2 and 3, the deflecting unit 104 may be fixed on the fixing base 23, and the deflecting unit 104 may be close to or abut against the first light splitting element 211.

It should be noted that the laser emission module may only have a light source, and a pulse laser beam emitted by the light source directly enters the light splitting module; or, the laser emission module may only include a light source and an optical fiber connection assembly, and the pulse laser beam emitted by the light source is transmitted through the optical fiber connection assembly and then enters the light splitting module.

In some embodiments, as shown in fig. 9, the converging unit 402 includes a filtering subunit 4021 and a converging subunit 4022, the filtering subunit 4021 is disposed before the converging subunit 4022 along the receiving optical path, the filtering subunit 4021 is configured to transmit the echo beam reflected by the reflecting unit 401 and filter an optical signal outside a preset wavelength range, and the converging subunit 4022 is configured to converge the echo beam transmitted by the filtering subunit. In a specific embodiment, the above-mentioned converging subunit 4022 may be a lens, i.e., composed of one or more, i.e., two or more, lenses.

In some embodiments, as shown in fig. 9, the detecting unit 403 includes a receiving circuit board 4031, and the receiving circuit board 4031 is provided with at least one detector, which is disposed on a side surface of the receiving circuit board 4031 facing the converging unit 402. The detector may be a PIN photosensor, an avalanche photodiode, or a geiger mode avalanche photodiode. Preferably, the photosensitive surface of the detector may be located at the focal plane of the converging subunit 4022.

In some embodiments, the receiving module further includes a receiving and adjusting bracket, the receiving and adjusting sub-bracket is provided with a mounting portion for adjusting and fixing N receiving circuit boards of the receiving module, and the receiving circuit boards are connected with the mounting portion. The receiving and adjusting bracket is connected with the bottom plate or the supporting body.

In some embodiments, the fixing base and the supporting body can be of an integrally formed structure, so that integration and convenient and quick installation of equipment are facilitated.

It should be understood that the above description is only exemplary of the present invention, and is not intended to limit the present invention, and that any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a laser radar, its characterized in that includes laser emission module, beam splitting module, scanning module, supporter and receiving module, wherein:

the laser emission module is used for emitting a pulse laser beam;

2. The lidar of claim 1, wherein the spectroscopy module comprises a spectroscopy element and a reflective element, wherein:

3. The lidar of claim 2, wherein the beam splitting element comprises a first beam splitting element and a second beam splitting element, wherein:

4. The lidar of claim 3, wherein the first incident beam, the second incident beam, and the third incident beam have a ratio of x: y: z, wherein y is ≧ x and y is ≧ z.

5. The lidar of claim 1, wherein the reflection unit is disposed on an optical path formed by the incident beam from the beam splitting module to the scanning module.

6. The lidar of claim 5, wherein the reflection unit has a light-transmitting portion for being penetrated to pass the incident light beam.

7. The lidar of claim 6, wherein the light-transmissive portion is a light-transmissive hole.

8. The lidar of claim 1, wherein the light-transmissive structure comprises N sets of optical channels, each set of optical channels comprising a first sub-optical channel and a second sub-optical channel, the first sub-optical channel and the second sub-optical channel being in communication, the first sub-optical channel and the second sub-optical channel being disposed at an included angle;

the first sub-optical channel is used for passing the incident light beam and the echo light beam;

9. The lidar of claim 8, wherein the support body has a first end and a second end, the first sub-optical channel communicating the first end and the second end, the second sub-optical channel communicating the second end;

the convergence unit is arranged in the second sub-optical channel.

10. The lidar of claim 9, wherein the second sub-optical channels of each set of the optical channels are parallel to each other, and the first sub-optical channel of each set of the optical channels is a path extending from the corresponding first end to the corresponding second end by a predetermined length in a predetermined direction, wherein the predetermined direction is a direction from a center point of the scanning module to a line connecting center points of the reflection units.

11. The lidar of claim 9, wherein the corresponding first end portions of each set of the optical channels intersect.

12. The lidar of claim 9, wherein the support body further has a third end, the second sub optical channel further connected to the third end; and/or the presence of a gas in the gas,

13. The lidar of claim 1, wherein the laser emission module comprises a collimating unit for adjusting the pulsed laser beam into a parallel beam and incident to the beam splitting module;

14. The lidar of claim 1, wherein the extinction member is an extinction cylinder, one end of the extinction cylinder is connected to the support, and the other end of the extinction cylinder is opened toward the detection unit.

15. The lidar of claim 14, wherein the inner wall of the extinction cylinder is in a tapered multi-section stepped hole structure, the large diameter end of the extinction cylinder is connected to the supporting body, and the outlet of the small diameter end of the extinction cylinder faces the detection unit.

16. The lidar of claim 15, wherein the inner side wall of the extinction cylinder is provided with one or a combination of any of extinction threads, an extinction ring and an extinction material.

17. The lidar of claim 1, wherein the extinction member is made of metal or plastic.

18. The lidar of claim 1, wherein the scanning module has a movable portion having a reflective surface on a side thereof facing the spectroscopic module for reflecting the incident beam;

19. The lidar of claim 18, further comprising a control module connected to the lasing module, the scanning module, and the N detection units, respectively;

20. The lidar of claim 19, further comprising a housing and a base plate, wherein the bottom end of the housing has an opening, and the housing and the base plate are hermetically connected to form an accommodating cavity;

21. The lidar of claim 20, further comprising a power module disposed within the receiving chamber;

22. Lidar according to claim 21, wherein at least a partial region of the outer side of the housing is provided with heat dissipating teeth.

23. The lidar of claim 1 or 7, wherein the laser emission module comprises a light source and a fiber optic connection assembly, wherein:

the light source is used for emitting the pulse laser beam;

24. The lidar of claim 13, wherein the laser emitting module further comprises a deflecting unit disposed between the collimating unit and the beam splitting module, and configured to deflect the parallel beam adjusted by the collimating unit and to emit the deflected parallel beam to the beam splitting module.

25. The lidar of claim 21, wherein a hollowed-out region is disposed on the sidewall, the hollowed-out region being opposite to the light exit side of the scanning module, the lidar further comprising a front window covering the hollowed-out region for transmitting the incident light beam reflected by the scanning module and transmitting the echo light beam; and/or the presence of a gas in the gas,