WO2019136854A1 - 激光雷达及其工作方法 - Google Patents

激光雷达及其工作方法 Download PDF

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Publication number
WO2019136854A1
WO2019136854A1 PCT/CN2018/081367 CN2018081367W WO2019136854A1 WO 2019136854 A1 WO2019136854 A1 WO 2019136854A1 CN 2018081367 W CN2018081367 W CN 2018081367W WO 2019136854 A1 WO2019136854 A1 WO 2019136854A1
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WO
WIPO (PCT)
Prior art keywords
laser
laser beam
grating
angle
laser radar
Prior art date
Application number
PCT/CN2018/081367
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English (en)
French (fr)
Inventor
王瑞
李娜
卢炎聪
向少卿
李一帆
Original Assignee
上海禾赛光电科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Priority claimed from CN201810036235.4A external-priority patent/CN108226945A/zh
Priority claimed from CN201810045754.7A external-priority patent/CN108375762B/zh
Priority claimed from CN201810045703.4A external-priority patent/CN108226899B/zh
Application filed by 上海禾赛光电科技有限公司 filed Critical 上海禾赛光电科技有限公司
Priority to KR1020207019296A priority Critical patent/KR102532239B1/ko
Priority to JP2020538624A priority patent/JP7322037B2/ja
Priority to EP18899543.5A priority patent/EP3742199A4/en
Priority to US16/011,127 priority patent/US10473767B2/en
Publication of WO2019136854A1 publication Critical patent/WO2019136854A1/zh
Priority to US16/564,842 priority patent/US10816647B2/en
Priority to US17/032,192 priority patent/US12019187B2/en
Priority to US18/375,870 priority patent/US20240027587A1/en
Priority to US18/384,631 priority patent/US20240061086A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4814—Constructional features, e.g. arrangements of optical elements of transmitters alone
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/42—Simultaneous measurement of distance and other co-ordinates
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
    • G01S17/931—Lidar systems specially adapted for specific applications for anti-collision purposes of land vehicles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4811—Constructional features, e.g. arrangements of optical elements common to transmitter and receiver
    • G01S7/4812—Constructional features, e.g. arrangements of optical elements common to transmitter and receiver transmitted and received beams following a coaxial path
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/10—Scanning systems
    • G02B26/105—Scanning systems with one or more pivoting mirrors or galvano-mirrors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10—Beam splitting or combining systems
    • G02B27/106—Beam splitting or combining systems for splitting or combining a plurality of identical beams or images, e.g. image replication
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10—Beam splitting or combining systems
    • G02B27/1086—Beam splitting or combining systems operating by diffraction only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4814—Constructional features, e.g. arrangements of optical elements of transmitters alone
    • G01S7/4815—Constructional features, e.g. arrangements of optical elements of transmitters alone using multiple transmitters

Definitions

  • the invention relates to the field of photoelectric detection, in particular to a laser radar and a working method thereof.
  • Lidar is a commonly used ranging sensor with long detection range, high resolution and low environmental interference. It is widely used in intelligent robots, drones, and unmanned driving.
  • the working principle of the lidar is similar to that of the microwave radar. It uses the time it takes for the light wave to travel between the radar and the target to estimate the distance.
  • the initial lidar was a single-line lidar, that is, there was only one laser and detector, and its scanning target range was limited, which easily caused the lack of detection targets.
  • multi-line lidars are increasingly becoming the focus of research and commercial use. Multi-line lidars are arranged in the vertical direction using multiple lasers and corresponding detectors, increasing the detection range in the vertical direction.
  • the existing multi-line radar has the disadvantages of high cost and difficulty in installation.
  • the problem solved by the present invention is to provide a laser radar and a working method thereof, which can reduce the cost of the laser radar device and is simple to install.
  • the invention provides a laser radar, comprising: a transmitting device, wherein the transmitting device is adapted to generate a first laser beam; and a beam splitting device, wherein the beam splitting device is adapted to divide the first laser beam into a plurality of seconds propagating in different directions a laser beam; at least a portion of the second laser beam is reflected by the object to be detected to form an echo beam; and receiving means adapted to receive the echo beam.
  • the spectroscopic device has an optical axis, and a plane perpendicular to the optical axis is a target plane; and the spectroscopic device is further adapted to make the plurality of second laser beams become dense in the target plane distributed.
  • the spot formed by the second laser beam gradually decreases in density in a direction away from the optical axis.
  • the spectroscopic device has an adjustment axis parallel to the optical axis; the spectroscopic device is adapted to rotate around the adjustment axis to change a propagation direction of the plurality of second laser beams.
  • the spectroscopic device is a grating or a fiber splitter.
  • the spectroscopic device is a Daman grating.
  • the spectroscopic device is a one-dimensional grating, the spectroscopic device has a first grating period in a first direction; the first grating period is d, and the wavelength of the first laser beam is ⁇ ,
  • the spectroscopic device is an m ⁇ 1 splitting grating, m is a number of splitting of the laser beam along the first direction; and the angle of rotation of the spectroscopic device around the adjustment axis is smaller than Where ⁇ is the preset angle of view.
  • the first grating period of the spectroscopic device is in a range of 47 ⁇ m to 57 ⁇ m; and the wavelength of the first laser beam is in a range of 895 nm to 915 nm.
  • the spectroscopic device is a two-dimensional grating, the spectroscopic device has a first grating period in a first direction and a second grating period in a second direction, the first direction being perpendicular to the second direction;
  • the first grating period is d 1
  • the second grating period is d 2
  • the wavelength of the first laser beam is ⁇
  • the beam splitting device is an m ⁇ n splitting grating
  • m is along the first
  • the first grating period of the spectroscopic device is in a range of 47 ⁇ m to 57 ⁇ m; the wavelength of the first laser beam is in a range of 895 nm to 915 nm; and the second grating period is in a range of 47 ⁇ m to 57 ⁇ m.
  • the transmitting device has a scanning rotating axis intersecting the first laser beam propagation direction, the transmitting device is adapted to rotate around the scanning rotating axis; the optical axis of the beam splitting device and the scanning rotation The angle of the shaft is greater than 0° and less than or equal to 90°.
  • the spectroscopic device has at least one splitting direction perpendicular to an optical axis, the splitting direction and a plane of the optical axis being a splitting plane; and the plurality of second laser beams are on at least one of the splitting planes
  • the projections are offset from each other; the angle between the splitting direction and the scanning rotation axis is greater than or equal to 0° and less than 90°.
  • the light splitting device is a grating
  • the light splitting device has a first grating period in a first direction
  • the light splitting direction is the first direction
  • the method further includes: a galvanometer, the galvanometer includes a first reflecting surface, wherein the first reflecting surface is adapted to reflect the second laser beam; the galvanometer has a vibration rotating axis, and the galvanometer is suitable Rotating around the vibration rotation axis, an angle between the vibration rotation axis and a normal line of the first reflection surface is greater than zero.
  • the beam splitting device is a one-dimensional grating, and the plurality of second laser beams are located in the same plane; a plane of the plurality of second laser beams projected to the first reflecting surface is a propagation plane, and the A reflecting surface has an intersection with the propagation plane, and an angle between the vibration rotating axis and the intersection line is greater than 0°.
  • the transmitting device has a scanning rotating axis intersecting the first laser beam propagation direction, and the transmitting device is adapted to rotate around the scanning rotating axis; the vibration rotating axis and the scanning rotating axis The angle between them is greater than 0°.
  • the method further includes: a half mirror, wherein the half mirror is adapted to transmit at least a portion of the second laser beam and incident on a first reflecting surface of the galvanometer;
  • the transflective mirror includes a second reflective surface adapted to reflect an echo beam reflected back through the galvanometer into the receiving device.
  • the method further includes: receiving a convergence lens for concentrating an echo beam emitted through the half mirror into the receiving device; a distance between the receiving device and the focus of the receiving condenser lens is smaller than receiving The condenser lens is half the depth of focus.
  • the transmitting device is adapted to simultaneously generate a plurality of first laser beams having different propagation directions.
  • the present invention also provides a working method of a laser radar, comprising: providing a laser radar, the laser radar comprising: a transmitting device, wherein the transmitting device is adapted to generate a first laser beam; and the spectroscopic device, wherein the spectroscopic device is suitable Separating the first laser beam into a plurality of second laser beams propagating in different directions; the second laser beam is reflected by the object to be detected to form an echo beam; and receiving means, the receiving device is adapted to receive the echo a light beam; causing the emitting device to generate a first laser beam; the first laser beam passing through the beam splitting device, divided into a plurality of second laser beams having different propagation directions; at least part of the second laser beam reaching the The object to be detected is reflected back to form an echo beam; the echo beam is received by the receiving device.
  • the spectroscopic means is adapted to gradually reduce the distribution density of the plurality of second laser beams in a direction away from the optical axis in a plane perpendicular to the optical axis.
  • the dense distribution of the plurality of second laser light velocities enables more of the second laser beam to be concentrated on the horizontal line and close to the ground, so that the laser radar is hindered during the running of the vehicle.
  • the location of the object has a high angular resolution, which can effectively improve the accuracy of the recognition of the obstacle by the laser radar, and is beneficial to expanding the application prospect of the laser radar on the vehicle.
  • the light splitting device is a grating; the light splitting device has at least one light splitting direction perpendicular to the optical axis, and the light splitting direction and the plane of the optical axis are a light splitting plane; The projections of the laser beams on at least one of the beam splitting planes are offset from each other; the angle of the splitting direction with the scanning axis of rotation is greater than or equal to 0° and less than 90°.
  • the emitting device includes a plurality of lasers and a converging lens in which the light emitting directions are parallel to each other, and the converging lens is adapted to converge the first laser beam generated by the plurality of lasers to the spectroscopic device;
  • the lens is capable of causing a plurality of lasers having the same light-emitting direction to generate a first laser beam that is concentrated to the spectroscopic device, thereby reducing the mounting difficulty of the plurality of lasers and generating a plurality of first laser beams having different propagation directions, thereby
  • the installation difficulty of the plurality of lasers can be effectively reduced, the installation cost is reduced, the accuracy of the optical path of the first laser beam can be effectively improved, and the detection accuracy and detection precision of the laser radar are improved.
  • the first laser beam is divided into a plurality of second laser beams by the spectroscopic device, and a plurality of second laser beams can be obtained by one laser, thereby saving a large amount of lasers. Furthermore, the cost and installation difficulty of the laser radar can be reduced.
  • the lidar has a high field of view and angular resolution and is low in cost.
  • the spectroscopic device is rotated to change a propagation direction of the plurality of second laser beams according to a preset vertical resolution.
  • the rotation direction of the plurality of second laser beams can be changed by the rotation of the spectroscopic device to achieve the purpose of adjusting the vertical angular resolution of the laser radar, and the laser radar can be resolved at a high angle under different environmental requirements.
  • the balance of the rate and the large angle of view is beneficial to improve the detection accuracy and accuracy of the laser radar.
  • 1 is a schematic structural view of a multi-line laser radar laser
  • Figure 11 is a schematic diagram of an enlarged optical path of an echo beam in the embodiment of the laser radar shown in Figure 9;
  • FIG. 12 is a schematic diagram of a spot formed by the plurality of second laser beams on the target plane when the galvanometer is stationary, in the embodiment of the laser radar shown in FIG. 9;
  • Figure 16 is a schematic view showing the distribution of spots formed on the target plane before and after the rotation of the spectroscopic device in the embodiment of the laser radar shown in Figure 15;
  • Lidar devices have many problems, such as high cost and difficulty in installation. Now combined with a kind of laser radar, the reason why the laser radar is high in cost and difficult to install is analyzed.
  • the laser radar apparatus mainly includes a laser for emitting laser light and a detector for receiving light reflected back by the object to be inspected.
  • the laser emits laser light to the object to be inspected; after the emitted laser light is projected onto the object to be inspected, it is reflected by the target and folded back and collected by the detector.
  • the laser of the multi-line laser radar includes a plurality of lasers 10 for emitting laser light and a lens 20 for causing laser beams emitted from lasers 10 at different positions to have different propagation directions.
  • the plurality of lasers 10 are distributed in a plane perpendicular to the main optical axis of the lens 20 (horizontal plane in Fig. 1).
  • the present invention provides a laser radar and a working method thereof.
  • the first laser beam is divided into a plurality of second laser beams by a beam splitting device, and a plurality of second laser beams can be obtained by one laser, thereby enabling A large number of lasers are saved, which in turn can reduce the cost and installation difficulty of the laser radar.
  • the lidar has a high field of view and angular resolution and is low in cost.
  • the laser radar includes: a transmitting device 110 (shown in FIG. 3), the transmitting device 110 is adapted to generate a first laser beam 110a; a beam splitting device 120 (shown in FIG. 3), and the beam splitting device 120 is adapted to The first laser beam 110a is divided into a plurality of second laser beams 120b propagating in different directions; at least part of the second laser beams 120b are reflected by the object to be detected to form an echo beam; and the receiving device 130 is adapted to receive The echo beam.
  • the spectroscopic device 120 is capable of dividing the first laser beam 110a into a plurality of second laser beams 120b propagating in different directions.
  • the second laser beam 120b propagating in different directions can detect the object to be detected in different directions, thereby increasing the field angle and angular resolution of the laser radar; dividing the first laser beam 110a into multiple beams by the beam splitting device
  • the second laser beam 120b can obtain a plurality of second laser beams by one laser, thereby saving a large amount of lasers, thereby reducing the cost and installation difficulty of the laser radar.
  • the lidar has a high field of view and angular resolution and is low in cost.
  • the emitting device 110 acts as a light source for generating a first laser beam 110a.
  • the transmitting and receiving module 100 includes a transmitting structure 101 and a receiving device 130, and the transmitting structure 101 includes the transmitting device and the beam splitting device 120.
  • the laser radar further includes: a fixing mechanism 102, wherein the fixing mechanism 102 is suitable for realizing the fixing of the entire laser radar; a rotating mechanism 103, the rotating mechanism 103 is located at the transmitting and receiving module 100 and the Between the fixing mechanisms 102, the rotating mechanism 103 is adapted to implement a connection between the transmitting and receiving module 100 and the fixing mechanism 102.
  • the laser radar is mounted on the ground, and the laser radar is fixed relative to the ground.
  • the scanning rotation axis 111 is perpendicular to a horizontal plane.
  • the lidar may be mounted on a car or aircraft, and the scanning axis of rotation may be oblique to the horizontal plane.
  • the wavelength of the first laser beam 110a is in the range of 895 nm to 915 nm, for example, 905 nm.
  • the laser in the range of 895 nm to 915 nm is an infrared laser with high penetrability, which is invisible light. Therefore, setting the wavelength range of the first laser beam 110a reasonably can effectively reduce the interference of the laser radar to the surrounding environment. The detection distance of the laser radar can be effectively improved.
  • the spectroscopic device 120 is configured to achieve splitting, thereby dividing the first laser beam 110a into a plurality of second laser beams 120b propagating in different directions.
  • the laser radar further includes: a beam expanding collimating device 140, wherein the beam expanding collimating device 140 is disposed between the transmitting device 110 and the beam splitting device 120. In the optical path of the laser beam 110a.
  • the beam splitting device 120 can divide a first laser beam 110a into a plurality of second laser beams 120, reduce the number of lasers, reduce the cost and assembly difficulty of the laser radar under the premise of increasing the resolution of the laser radar angle. In order to achieve both performance improvement and cost reduction.
  • the spectroscopic device 120 has an optical axis 121, and the extending direction of the optical axis 121 is consistent with the propagation direction of the formed second laser beam 120b.
  • the emitting device 110 has a scan.
  • the rotation axis 111, the angle between the optical axis 121 of the spectroscopic device 120 and the scanning rotation axis 111 is greater than 0° and less than or equal to 90°, that is, the optical axis 121 and the scanning rotation axis 111 intersect.
  • the emission is performed along with the The rotation of the device 110 changes the direction of propagation of the first laser beam 110a, and the direction of propagation of the plurality of second laser beams 120a also changes, thereby enabling the plurality of second laser beams 120a to face a certain space.
  • the scanning can effectively improve the spatial resolution of the laser radar, which is beneficial to the improvement of the detection capability of the laser radar.
  • the optical axis 121 is perpendicular to the scanning rotation axis 111, so that the scanning of the plurality of second laser beams 120a in a range of 360° in the plane perpendicular to the scanning rotation axis 111 can be effectively ensured. Effectively expanding the field of view of the laser radar in the plane perpendicular to the scanning rotation axis 111 is advantageous for the expansion of the lidar detection range.
  • the step of preventing the splitting direction 124 from being perpendicular to the scanning rotation axis 111 enables the plurality of second laser beams 120b to form a certain divergence angle, thereby effectively improving the vertical angular resolution of the laser radar, thereby facilitating improvement.
  • the detection capability of the lidar. Therefore, the plurality of second laser beams 120b formed include a plurality of second laser beams 120b whose propagation directions are different from the scanning rotation axis 111, and the laser radar can be increased parallel to the scanning rotation axis 111. Angle resolution and field of view.
  • the plurality of second laser beams include a plurality of second laser beams having the same angle of propagation as the axis of rotation.
  • the light splitting direction 124 and the scanning rotation axis 111 are parallel to each other, and the divergence angle of the plurality of second laser beams 120b can be effectively increased, thereby increasing the vertical angle of view of the laser radar. It is beneficial to expand the detection range of the laser radar.
  • the laser radar is mounted on the ground, the scanning rotating shaft 111 is perpendicular to a horizontal plane, and thus the optical axis 121 of the spectroscopic device 120 is parallel to a horizontal plane, and the transmitting device 110 rotates around the scanning rotating axis 111 of a vertical horizontal plane. Therefore, the plurality of second laser beams are propagated in various directions in the horizontal plane, and the angle of view and the horizontal angle resolution of the laser radar in the horizontal direction can be effectively increased.
  • a large horizontal field of view angle and a large horizontal angle resolution can effectively expand the detection range of the laser radar, and is beneficial to improving the laser radar.
  • the light splitting direction 124 is parallel to the scanning rotation axis 111, and thus the light splitting direction is perpendicular to a horizontal plane, so the spectroscopic device 120 can form a first laser beam 110a to form a plurality of second staggered in the vertical horizontal direction.
  • the laser beam 120b can improve the vertical angular resolution of the laser radar without increasing the number of lasers and reducing the vertical field of view of the laser radar, thereby effectively improving the obstacles around the traffic equipment of the laser radar.
  • the detection success rate is beneficial to achieve a large angle of view, high angular resolution, and low manufacturing cost, which is beneficial to make the laser radar more suitable for transportation applications.
  • the plane perpendicular to the optical axis 121 is the target plane 123
  • the beam splitting device 120 is further adapted to distribute the spots formed by the plurality of second laser beams 120b in the target plane 120. That is to say, the spot formed after the plurality of second laser beams 120b are projected onto the target plane 123 is non-uniformly distributed.
  • the second laser beam 120b is concentrated on a partial area of the target plane 123, thereby increasing the density of the second laser beam 120b in a partial space between the beam splitting device 120 and the target plane 123, thereby achieving partial spatial angular resolution.
  • the improvement of the local spatial angular resolution and the utilization of the second laser beam 120b reduce the number of the second laser beam 120b without the detecting function, and can effectively reduce the laser under the premise of ensuring the local angular resolution.
  • the number is beneficial to reduce the manufacturing cost and assembly difficulty, and can also reduce the system load, is beneficial to increase the scanning frequency, and is beneficial to improve the performance of the laser radar.
  • Having more of the second laser beam 120b concentrated in the vicinity of the optical axis 121 can effectively improve the angular resolution of the space of the laser radar in the vicinity of the optical axis 121 without increasing equipment cost and assembly difficulty.
  • the rate is favorable for improving the utilization rate of the second laser beam 120b, and is advantageous for achieving both manufacturing cost and detection performance.
  • the transmitting device 110 is rotatable around the scanning rotating shaft 111, and the plurality of second laser beams 120b are in a direction of intersection with the scanning rotating shaft 111, and thus are perpendicular to the scanning rotating shaft 111.
  • the angular resolution of the lidar is related to the rate of change of the direction of propagation of the second laser beam 120b, i.e., to the rate of rotation of the transmitting device 110.
  • the magnitude of the field of view of the laser radar, the angular resolution level is related to the number of the second laser beam 120b and the interval between adjacent second laser beams, and
  • the splitting direction is related to the angle between the scanning axis 111.
  • the object to be detected is usually an obstacle near a bottom surface of a pedestrian, a vehicle, or the like, so that more second laser beams 120b are concentrated near the optical axis 121.
  • the method that is, concentrating more of the second laser beam 120b near the ground, thereby improving the vertical angular resolution of the laser radar without increasing the manufacturing cost, assembling difficulty, and reducing the vertical angle of view.
  • the spatial distribution of the plurality of second laser beams 120b can be more suitable for a real traffic environment, which is advantageous for making the laser radar more suitable for applications in the transportation field.
  • the increase of the vertical angle resolution of the horizontal surface and the bottom surface attachment can reduce the number of lasers under the premise of ensuring the vertical angle resolution, which is advantageous for reducing manufacturing cost and assembly difficulty, and also reducing system load. It is beneficial to increase the scanning frequency and is beneficial to improve the scanning accuracy of the laser radar.
  • the grating divides one of the first laser beams 110a into the plurality of second laser beams 120b by diffraction and interference of light.
  • the light splitting device 120 is a grating
  • the light splitting device 120 has a first grating period in a first direction
  • the light splitting direction 124 of the light splitting device 120 includes the first direction.
  • the grating principle formula is:
  • the sine function value of the angle is close to the corresponding angle value; when the angle is small, the sine function value of the angle is smaller than the corresponding angle value, and the larger the angle, the sine function value of the angle and the corresponding angle value The difference between the two is greater.
  • the angle ⁇ between the second laser beam 120b and the normal to the grating plane is small, and the angle ⁇ and the diffraction of the second laser beam 120b are small.
  • the order m is linear; when the diffraction order m of the second laser beam 120b is large, the angle ⁇ between the second laser beam 120b and the normal to the grating plane is larger, and the angle ⁇ is larger than
  • the sinusoidal function value of the included angle ⁇ is larger than the linear relationship of the diffraction order m of the second laser beam 120b.
  • the angle ⁇ between the second laser beam 120b and the normal to the grating plane and the difference between the angles ⁇ of the second laser beam 120b of different stages and the normal of the grating plane Gradually increasing, that is, the angle between adjacent second laser beams 120b is gradually increased, that is, the second laser light 120b is more concentrated in the direction of the normal to the grating plane.
  • the spectroscopic device 120 when configured as a grating, the direction of the normal of the grating plane is parallel to the optical axis 121. Therefore, the method of setting the spectroscopic device 120 as a grating can enable A plurality of second laser beams 120b are concentrated on the optical axis 121.
  • the method of disposing the spectroscopic device 120 as a grating not only enables the spectroscopic device 120 to perform the function of splitting to reduce the number of lasers, but also enables the second laser beam 120b to exhibit a dense and non-uniform distribution.
  • the second laser light 120b is concentrated more in the direction of the optical axis 121, so that low cost, high angular resolution, and large angle of view can be achieved, which is advantageous in achieving cost control and performance improvement.
  • the light splitting by the grating the number of optical components is small, the optical path structure is simple, and the optical path precision of the laser radar is improved; and the grating manufacturing process is mature, the manufacturing cost is low, and the light splitting device 120 is set as a grating.
  • the manufacturing cost of the spectroscopic device 120 can be effectively reduced.
  • the spectroscopic device 120 is a Daman grating.
  • a Daman grating is a phase grating with unequal spacing and periodic repetition.
  • a Daman grating is a diffractive optical element that splits a single beam into several equal-intensity beams. Therefore, the spectroscopic device 120 is configured as a Daman grating, and the first laser beam 110a can be divided into a plurality of second laser beams 120b having different light intensities in different directions, which can effectively improve the plurality of The uniformity of the intensity of the second laser beam 120b can be avoided because a certain light intensity of the plurality of second laser beams 120b is too small to be detected, and the detection distance of the plurality of second laser beams 120b can be effectively ensured.
  • the successful detection of the echo beam by the receiving device 130 is beneficial to improving the detection distance of the laser radar, and is advantageous for achieving high vertical angle resolution and large detection distance, and is beneficial to improving the laser radar. The accuracy and accuracy of the detection of the target to be detected.
  • the Daman grating includes a plurality of first and second regions alternately arranged.
  • the distance between adjacent first regions or the distance between adjacent second regions is the grating period of the grating.
  • the widths of the plurality of first regions of the Daman grating are different, and the widths of the plurality of second regions are different.
  • the Daman grating makes the light intensity of the generated plurality of second laser beams equal by rationally designing the grating period, the first region width, and the second region width.
  • the spectroscopic device 120 is a one-dimensional Daman grating. Therefore, in the spectroscopic device 120, the first region and the second region are strips having parallel extending directions, and the first region and the second region are The extending direction of the region is perpendicular to the light splitting direction; and the light splitting direction 124 is perpendicular to the horizontal plane, so that the extending direction of the first region and the second region is parallel to the horizontal plane.
  • the spectroscopic device 120 is a one-dimensional Darman grating, and the one-dimensional Darman grating is designed and manufactured at a low cost, and can effectively control the manufacturing cost of the laser radar.
  • the spectroscopic device 120 is a 1 ⁇ 9 split-beam one-dimensional Daman grating.
  • the spectroscopic device 120 may also be configured as a 1 ⁇ 5 split, 1 ⁇ 15 split, 1 ⁇ 32 split, or 1 ⁇ 64 split Daman grating.
  • the magnitude of the angle ⁇ between the second laser beam 120b and the normal to the grating plane is related to the diffraction order m, the wavelength ⁇ of the first laser beam 110a, and the grating period d. Therefore, the wavelength ⁇ of the first laser beam 110a is constant, and in the case where the parameters of the spectroscopic device 120 are determined, the angle ⁇ between the second laser beam 120b of different orders and the normal of the grating plane is different, that is, multiple beams can be obtained.
  • a second laser beam 120b that propagates in different directions.
  • the grating period of the one-dimensional Daman grating is in the range of 47 ⁇ m to 57 ⁇ m, for example, 52 ⁇ m.
  • the phase turning points of the spectroscopic device 120 are 0.06668, 0.12871, 0.28589, 0.45666, and 0.59090.
  • the spectroscopic device may also be configured as a two-dimensional Daman grating, and the two-dimensional Daman grating can make the horizontal emission angle and the vertical emission angle of the second laser beam different.
  • the vertical angular resolution and horizontal angular resolution of the laser radar can be increased.
  • the horizontal direction is a direction parallel to the horizontal plane, which is perpendicular to the direction of the horizontal plane.
  • Figure 4 shows a schematic view of the receiving portion of the optical path of the laser radar embodiment of Figure 2.
  • the plurality of second laser beams 120b formed are emitted from the emission structure 101, at least part of the second laser beams 120b are projected onto the object to be detected, and reflected by the object to be detected to form an echo beam 130c; the receiving device 130 receives the echo beam 130c; and obtains information of the object to be detected according to the received echo beam 130c.
  • the receiving device 130 includes a plurality of detectors 131, and each of the detectors 131 is adapted to receive an echo beam 130c reflected by the corresponding second laser beam through the object to be detected.
  • the detector 131 is a photodiode or a photomultiplier tube, an avalanche photodiode or an infrared and visible light detector device.
  • the receiving device 130 further includes: a receiving condenser lens 132 adapted to converge the echo beam 130c to the detector 131, the beam splitting device 131 to the receiving converging lens 132
  • the focal plane is less than half the focal depth of the receiving condenser lens focal length 132.
  • the spectroscopic device 131 is located at a focal plane of the receiving converging lens 132.
  • the echo beam 130c formed by the second laser beam 120b having the same propagation direction is transmitted through the reception condenser lens 132 and condensed to the surface of the same detector 131; the echo beam 130c formed by the second laser beam 120b having different propagation directions
  • the receiving condenser lens 132 transmits and converges to different detectors 131. Therefore, according to the propagation direction of the echo beam 130c, the orientation of the object to be detected can be obtained.
  • the receiving device 130 is separate from the transmitting structure 101.
  • the discrete arrangement of the receiving device 130 and the transmitting structure 101 can prevent the echo beam 130c from passing through the beam splitting device 120, thereby avoiding the influence of the beam splitting device 120 on the propagation direction of the echo beam 130c, which is beneficial for determining The location of the target to be detected.
  • the receiving device 130 further includes an analyzing device (not shown). After the detector 131 receives the echo beam 130c, the optical signal of the echo beam 130c is converted into an electrical signal; the analyzing device is configured to analyze the electrical signal to obtain the target to be detected. position.
  • the present embodiment is the same as the first embodiment, and the present invention will not be described again.
  • the difference between the embodiment and the foregoing embodiment is that, in the embodiment, the spectroscopic device 220 has an adjustment shaft 225 parallel to an optical axis (not shown); the spectroscopic device 220 is suitable for the winding
  • the adjustment shaft 225 rotates to change the propagation direction of the plurality of second laser beams.
  • the rotation direction of the plurality of second laser beams can be changed by the rotation of the spectroscopic device 220 to achieve the purpose of adjusting the angular resolution of the laser radar; and the rotation of the spectroscopic device 220 can also be partially overlapped.
  • the second laser beam position is staggered to achieve the purpose of increasing the angular resolution; therefore, the spectroscopic device 220 is set to be rotatable, and the laser radar can be used in high-angle resolution and large-vision.
  • the balance of the field angle is beneficial to improve the detection accuracy and accuracy of the laser radar.
  • the spectroscopic device 220 is a two-dimensional grating. Therefore, the spectroscopic device 220 has a first grating period d 1 in a first direction and a second grating period d 2 in a second direction, the second direction being perpendicular to the first direction. Specifically, the spectroscopic device 220 is a two-dimensional Daman grating.
  • the exit angles of the plurality of second laser beams formed by the beam splitting device 220 and the wavelength of the first laser beam are ⁇ and the parameters of the spectroscopic device 220 are related.
  • the wavelength ⁇ of the first laser beam is in the range of 895 nm to 915 nm, for example, 905 nm.
  • the first grating period d 1 of the spectroscopic device 220 is in the range of 47 ⁇ m to 57 ⁇ m, for example 52 ⁇ m
  • the second grating period d 2 is in the range of 47 ⁇ m to 57 ⁇ m, for example 52 ⁇ m.
  • a rectangular coordinate system is established on the spectroscopic device 220: the mutually perpendicular x-direction and the y-direction are located in the grating plane of the spectroscopic device 220, and the spectroscopic device 220
  • the normal of the grating plane is the z direction. Therefore, the z direction is parallel to the optical axis direction.
  • the laser radar is mounted on the ground, the optical axis is parallel to the horizontal plane, so the y direction is perpendicular to the horizontal plane, and the x direction is parallel to the horizontal plane, that is, the plane defined by the x direction and the z direction is parallel to level.
  • the adjustment axis 225 of the spectroscopic device 220 is parallel to the optical axis, and thus the z-axis is parallel to the adjustment axis 225.
  • the rotation of the spectroscopic device 220 about the adjustment axis 225 is a rotation in the x-y plane with the z direction as the rotation axis.
  • the change in the angle between the first direction and the y direction of the spectroscopic device 220 is the angle at which the spectroscopic device 220 rotates about the adjustment axis 225.
  • the second laser beam emerging (only considering the phase term related to the direction of propagation) can be expressed as:
  • d 1 is the first grating period
  • d 2 is a second grating period
  • n x and n y represent diffraction orders in the x direction and the y direction, respectively.
  • the angle ⁇ between the second laser beam propagation direction and the grating plane normal is:
  • the angles between adjacent second laser beams are different for different diffraction orders n y in the y direction, however, since the first grating period d 1 is much larger than the wavelength of the first laser beam Therefore, the angle between the adjacent second laser beams having different diffraction orders n y in the y direction is approximately equal.
  • the plurality of second laser beams are arranged in a matrix on the target plane, and FIG. 6 shows that the laser radar embodiment shown in FIG. 5 is at an angle of 0 between the first direction and the positive y direction.
  • the angle ⁇ between the second laser beam propagation direction and the grating plane normal is:
  • the spots formed by the plurality of second laser beams on the target plane are still arranged in a matrix, but as the spectroscopic device 220 rotates, the matrix formed by the spots also rotates, and FIG. 7 shows the first
  • the angle between the direction and the acute angle of the y direction is At the time, the laser radar embodiment shown in Figure 5 is a schematic representation of the spot formed on the target plane.
  • the spots arranged in the x direction are staggered as the spectroscopic device 220 rotates; each spot on the target plane corresponds to one of the second laser beams, and the adjacent spot in the y direction.
  • the splitting device 220 rotates, a difference occurs between more second laser beams and a horizontal plane, that is, the rotation of the spectroscopic device 220 can effectively improve the vertical angle resolution of the laser radar. rate. Therefore, the spectroscopic device 220 is set to be rotatable, and the angular resolution of the laser radar can be realized under different environmental requirements, which is beneficial to improving the detection precision and accuracy of the laser radar.
  • the spectroscopic device 220 is an m ⁇ n split two-dimensional Daman grating, m is a number of second laser beams formed along the first direction, and n is a location along the second direction. The number of second laser beams is formed.
  • the first direction is parallel to the y direction, that is, the angle between the first direction and the y direction is When it is 0, the position of the spectroscopic device 220 is the initial position.
  • the change in the angle between the first direction and the y direction of the spectroscopic device 220 is the angle at which the spectroscopic device 220 rotates about the adjustment axis 225. Therefore, the first direction and the y direction are at an acute angle The angle of the spectroscopic device 220 is rotated about the adjustment axis 225.
  • the angle at which the spectroscopic device 220 rotates around the adjustment shaft 225 is To In the range, that is, the angle between the first direction and the y direction in To Within the scope.
  • Reasonably setting the range of rotation angle of the spectroscopic device 220 can not only increase the angular resolution of the laser radar, but also can approach the distance between adjacent spots in the y direction, so that the angle between adjacent second laser beams is increased. Consistent, thereby improving the uniformity of the distribution of the second laser beam in the vertical direction, which is beneficial to the improvement of the performance of the laser radar.
  • the spectroscopic device 220 is 32 ⁇ 32 split, the first grating period d 1 and the second grating period d 2 are 52 ⁇ m, and the first laser beam wavelength is 905 nm.
  • the angle of view of the laser radar is about 30°, and the angle between the second laser beam and the horizontal plane is in the range of -20° to +10°, adjacent to the second laser beam.
  • the angles are approximately equal, so the vertical angular resolution of the lidar is about 0.9375° (30°/32) before rotation; after rotation, the vertical angular resolution of the lidar is about 0.0293° (30°/ (32 ⁇ 32)).
  • the laser radar has a high angular resolution in a direction parallel to the axis of rotation.
  • the spectroscopic device may also be a 5 ⁇ 5 splitting, 8 ⁇ 8 splitting, 16 ⁇ 16 splitting or 5 ⁇ 8 splitting Daman grating.
  • the spectroscopic device is configured as a two-dimensional Dammann grating. But this practice is only an example.
  • the light splitting device may also be configured as a one-dimensional grating to reduce the manufacturing cost of the grating and the manufacturing process difficulty, thereby achieving the purpose of controlling the cost.
  • the spectroscopic device may also be configured as a one-dimensional Darman grating.
  • the spectroscopic device When the spectroscopic device is configured as a one-dimensional grating, the spectroscopic device has a first grating period d 1 along a first direction, and an angle between a second laser beam propagation direction and a y direction is:
  • ⁇ is the wavelength of the first laser beam, It is an acute angle between the first direction of the spectroscopic device and the y direction.
  • n y is the diffraction order in the y direction.
  • the spot 341 is a spot formed when the angle between the first direction and the y direction of the spectroscopic device is 0; the angle between the first direction and the y direction of the spectroscopic device 342 is The spot formed by the time.
  • the distance between adjacent spots decreases in the y direction, and the angle between adjacent second laser beams decreases, and the vertical resolution of the laser radar increases accordingly.
  • the farthest distance between the plurality of spots 341 is r 1 along the y direction; the first of the spectroscopic devices
  • the angle between the direction and the acute angle of the y direction is In the y direction, the farthest distance between the plurality of spots 342 is r 2 ; obviously, r 1 is greater than r 2 .
  • the farthest distance between the spots is related to the vertical field of view of the lidar: in the y-direction, the greater the distance between the spots, the greater the vertical field of view. Therefore, in this embodiment, the vertical field of view of the laser radar decreases as the spectroscopic device rotates.
  • the spectroscopic device is a one-dimensional grating, the spectroscopic device has a first grating period along a first direction; the first grating period is d, and the wavelength of the first laser beam is ⁇ ,
  • the spectroscopic device is an m ⁇ 1 splitting grating, m is a number of splitting of the laser beam along the first direction; and the angle of rotation of the spectroscopic device around the adjustment axis is smaller than
  • ⁇ is the preset angle of view.
  • Properly setting the rotation angle of the spectroscopic device can make the field of view angle larger than the preset field of view angle ⁇ , so that the laser radar has a larger field of view angle while ensuring a higher angular resolution of the laser radar.
  • the preset viewing angle ⁇ is greater than or equal to 5°.
  • the spectroscopic device can be rotated around the adjustment axis, that is, the angle between the first direction and the y direction of the spectroscopic device is adjustable.
  • the position of the spectroscopic device may also be fixed, that is, the angles of the first direction and the y direction of the spectroscopic device are fixed values to improve the stability and accuracy of the laser radar optical path system. In order to achieve the purpose of improving the performance of the laser radar.
  • the angle between the adjacent second laser beam in the y direction can be reduced by making the first direction of the spectroscopic device at an angle with the y direction, in a limited second Under the premise of the number of laser beams, the purpose of improving the resolution of the upper angle in the y direction is achieved.
  • the transmitting device has a scanning rotating axis that intersects the first laser beam propagation direction, and the transmitting device is adapted to rotate around the scanning rotating axis;
  • the beam splitting device has at least a splitting direction perpendicular to the optical axis, the splitting direction and the plane of the optical axis being a splitting plane; projections of the plurality of second laser beams on at least one of the splitting planes are mutually offset;
  • the splitting direction is The angle of the scanning rotation axis is greater than or equal to 0° and less than 90°.
  • the light splitting device is a grating, the light splitting device has a first grating period in a first direction; and the light splitting direction is the first direction.
  • the spectroscopic device when configured as a grating, the spectroscopic device may be disposed such that an angle between the first direction and the scanning rotating axis is greater than or equal to 0° and less than 90°, so that the second laser beam is as far as possible
  • the direction of the scanning rotation axis is staggered, so that the angular resolution along the scanning rotation axis direction is improved with a limited number of second laser beams.
  • FIG. 10 is a schematic diagram of an enlarged optical path of a first laser beam and a second laser beam in a region 41 of the laser radar embodiment shown in FIG. 9.
  • FIG. 11 is an enlarged optical path diagram of an echo beam in the laser radar embodiment shown in FIG. .
  • the present embodiment is the same as the foregoing embodiment, and the present invention is not described herein again.
  • the laser radar further includes: a galvanometer 450, the galvanometer 450 includes a first reflective surface 450a, and the first reflective surface 450a is adapted to reflect The second laser beam; the galvanometer 450 has a vibration rotation axis (not shown), and the galvanometer 450 is adapted to rotate about the vibration rotation axis, the vibration rotation axis and the first reflection The angle between the normals of face 450a is greater than zero.
  • the propagation direction of the second laser beam reflected by the first reflection surface 450a can be changed, thereby increasing the scanning range of the second laser beam and increasing
  • the angle of view of the laser radar is large; and the rotation of the galvanometer 450 is as long as the minimum angle between the two laser beams before the rotation is scanned, and the obtained angle of view can reach the second laser beam.
  • the maximum angle between the angles therefore, the combination of the galvanometer 450 and the beam splitting device 420 can obtain a larger angle of view through the smaller Mirror 450 angle, so it can be effective under the same field of view.
  • the rotation angle of the galvanometer 450 is reduced, and the rotation period of the galvanometer 450 is reduced, thereby facilitating the scanning frame rate of the laser radar.
  • the spectroscopic device 420 is a one-dimensional grating. Specifically, the spectroscopic device 420 is a one-dimensional Daman grating. After being split by the spectroscopic device 420, the plurality of second laser beams formed are located in the same plane.
  • a plane of the plurality of second laser beams projected onto the first reflecting surface 450a is a plane of propagation (not shown), the first reflecting surface 450a having an intersection with the plane of propagation, the axis of vibration and the axis
  • the angle between the intersection lines is greater than 0°.
  • an angle between the vibration rotating shaft and the intersection line is 90°.
  • the transmitting device 410 has a scanning rotation axis (not shown) that intersects the first laser beam propagation direction, and the transmitting device 410 is adapted to rotate about the scanning rotation axis; the vibration rotation axis The angle between the scanning axis and the scanning axis is greater than 0°. In this embodiment, an angle between the vibration rotating shaft and the scanning rotating shaft is 90°.
  • the vibration rotation axis is parallel to the first reflection surface 450a.
  • the vibration rotation axis is parallel to the first reflection surface 450a to facilitate the mounting of the galvanometer 450.
  • the vibrating rotating shaft may have an acute angle with the first reflecting surface.
  • the galvanometer 260 is a laser scanning galvanometer or a microelectromechanical scanning galvanometer.
  • the laser radar further includes: a collimating lens 451, wherein the collimating lens 451 is adapted to collimate a plurality of second laser beams. And a focusing lens 452, wherein the focusing lens 452 is adapted to converge the collimated second laser beam to the first reflecting surface 450a of the galvanometer 450.
  • a distance between the spectroscopic device 420 and a focus of the collimating lens 451 is less than a half of a focal depth of the collimating lens 451. Specifically, the spectroscopic device 420 is located at a focal plane of the collimating lens 451. .
  • the distance between the galvanometer 450 and the focusing lens 452 is less than half the depth of focus of the focusing lens 452. Specifically, in the embodiment, the galvanometer 450 is located at a focal plane of the focusing lens 452.
  • the focus of the focus lens 452 coincides with the focus of the collimator lens 451, and the optical axis of the focus lens 452 coincides with the optical axis of the collimator lens 451.
  • the arrangement of the collimating lens 451 and the focusing lens 452 can increase the number of second laser beams that the second laser beam converges to the first reflecting surface of the galvanometer 450, thereby enabling the number of second laser beams reflected by the galvanometer 450 to be increased.
  • the angle of view of the lidar can be increased.
  • the first light beam is linearly polarized light. Since the polarization of the linearly polarized light has directivity, the degree of depolarization of the laser radar is small. Therefore, it is possible to filter out stray light having different polarization directions according to the polarization direction of the first light beam, thereby improving the signal-to-noise ratio of the laser radar.
  • the laser radar further includes: a half mirror 453, wherein the half mirror 453 is adapted to transmit at least part of the second laser beam and inject into The first reflecting surface 450a of the galvanometer 450; the half mirror 453 includes a second reflecting surface 453a, and the second reflecting surface 453a is adapted to reflect the echo beam reflected back through the galvanometer 450 to the In the receiving device 430.
  • the half mirror 453 can separate the echo beam from the second laser beam, thereby preventing the second laser beam from interfering with the receiving device 430, reducing the influence of the second laser beam on the detection result, and improving the laser.
  • the accuracy of the radar can also be achieved by using the semi-transparent mirror to achieve optical path overlap, thereby shortening the optical path of the laser radar, effectively reducing the volume of the optical system, and reducing the volume of the laser radar.
  • the second reflecting surface 453a of the half mirror 453 faces the first reflecting surface 450a of the galvanometer 450.
  • the laser radar further includes: a receiving convergence lens 454 for concentrating an echo beam emitted through the half mirror 453 into the receiving device 430; the receiving device 430 The distance from the focus of the receiving condenser lens 454 is less than half the focal depth of the second focus 454 lens.
  • the distance between the receiving converging lens 454 and the detector is less than half the depth of focus of the receiving converging lens 454.
  • the detector is located at a focal plane of the receiving condenser lens 454.
  • the lidar is capable of acquiring a larger field of view angle through a smaller oscillating mirror 260 rotation angle.
  • the performance of the laser radar in this embodiment is analyzed below.
  • the fractional device 420 is set as a 1 ⁇ 9 split-beam one-dimensional Darman grating.
  • the beam splitting device can also be provided as other parameters, other kinds of optical components, and cannot limit the invention.
  • the focusing lens 452 converges, and the plurality of second laser beams are focused on a central position of the first reflecting surface 450a.
  • a plane at any point on the surface of the object to be detected 409 is a target plane, and a distance between the target plane and a center position of the first reflective surface 450a is 1. It should be noted that, in this embodiment, the target plane is perpendicular to a horizontal plane.
  • FIG. 12 a schematic diagram of a spot formed by the plurality of second laser beams on the target plane at different moments of galvanic vibration is illustrated in the laser radar embodiment of Figure 9.
  • the established Cartesian coordinate system includes: an x direction, a y direction, and a z direction perpendicular to each other, wherein the y direction is parallel to the grating period direction of the spectroscopic device 420, that is, the y direction is parallel The light splitting direction of the spectroscopic device 420.
  • a plurality of second laser beams formed by the spectroscopic device 420 are reflected by the first reflecting surface 450a, and then projected onto the target plane to form a plurality of spots. 441.
  • the plurality of spots 441 form a 1 ⁇ 9 spot array on the target plane, and the spot array has an array period dy along the y direction, that is, a spacing between adjacent spots 441 in the y direction is dy.
  • the vibration rotation axis is parallel to the horizontal plane, and when the first reflection surface 450a rotates clockwise around the vibration rotation axis, the galvanometer The rotation angle of 450 is a positive value, and when the first reflection surface 450a is rotated counterclockwise about the vibration rotation axis, the rotation angle of the galvanometer 450 is a negative value.
  • the normal rotation angle of the first reflecting surface 450a is also + ⁇ radians, according to optical reflection.
  • the second laser beam reflected by the first reflecting surface 450a is rotated through an angle of 2 ⁇ radians.
  • the second after rotation A laser beam forms a spot 442 on the target plane.
  • the spot 442 is located on the side of the spot 441 along the positive y direction, and the interval between the spot 442 and the spot 441 is approximately dy/2.
  • the second laser beam forms a spot 443 on the target plane.
  • the spot 443 is located on the side of the spot 441 in the negative y direction, and the interval between the spot 443 and the spot 441 is approximately dy/2.
  • the region between the connected second laser beams can be scanned by the second laser beam.
  • the field of view of the laser radar is a superposition of the maximum angle between the rotation of the galvanometer 450 and the maximum angle between the plurality of second laser beams reflected by the galvanometer 450.
  • the rotation period of the mirror is beneficial to improve the scanning frame rate of the laser radar.
  • the rotation of the galvanometer 450 about the vibration rotation axis can increase the laser radar to rotate perpendicular to the scan.
  • the angle of view of the axis direction when the vibration rotating shaft has an acute angle with the propagation plane, the rotation of the galvanometer 450 about the vibration rotating axis can increase the direction of the laser radar in a direction perpendicular to the scanning rotation axis and parallel to the scanning rotation axis direction. Field of view.
  • the spectroscopic device may further be a two-dimensional Daman grating, and when the vibrating rotating shaft is not perpendicular to the first reflecting surface, the galvanometer rotates around the vibrating rotating shaft, By means of a smaller galvanometer rotation angle, the laser radar has a larger angle of view along a direction perpendicular to the scanning rotation axis and parallel to the scanning rotation axis direction, and the propagation range of the plurality of second laser beams can be effectively expanded. It is beneficial to increase the angular resolution and field of view of the laser radar in all directions.
  • FIG. 15 a schematic structural view of a fifth embodiment of the laser radar of the present invention is shown.
  • the present invention is the same as the foregoing embodiment, and the present invention is not described herein again.
  • the embodiment is different from the previous embodiment in that, in this embodiment, the transmitting device 510 is adapted to simultaneously generate a plurality of first laser beams having different propagation directions.
  • the spectroscopic device 520 can divide each of the first laser beams 510a into a plurality of second laser beams 520b, so that the generation of the plurality of propagating different first laser beams 510a can increase the number of the formed second laser beams 520b. Moreover, the second laser beam 520b generated by the first laser beam 510a having different propagation directions has different propagation directions, so that the angular resolution of the laser radar can be further increased.
  • the transmitting device 510 includes: a plurality of lasers 511, the light emitting directions of the plurality of lasers 511 are parallel to each other; and the collecting lens 512, the collecting lens 512 is suitable for making The first laser beam generated by the plurality of lasers 511 is concentrated to the spectroscopic device 520.
  • the concentrating lens 512 can generate a plurality of lasers 511 having the same light-emitting direction to generate a first laser beam 510a condensed to the spectroscopic device 520, thereby reducing the installation difficulty of the plurality of lasers 511 and generating a plurality of propagation directions.
  • Different first laser beams 510a can effectively reduce the installation difficulty of the plurality of lasers 511, which is advantageous for reducing the installation cost, and can effectively improve the accuracy of the optical path of the first laser beam 510a, and is advantageous for improving the laser light. Radar detection accuracy and detection accuracy.
  • the laser radar further has a plurality of beam expanding collimating devices (not shown), and the plurality of beam expanding collimating devices are in one-to-one correspondence with the plurality of lasers 511, and the beam expanding The straight devices are respectively used to diffuse and collimate the first laser beam generated by the corresponding laser.
  • the optical axis of the converging lens 512 coincides with the optical axis of the spectroscopic device 520; the light emitting direction of the plurality of lasers 512 is parallel to the optical axis of the converging lens 512.
  • the plurality of first laser beams 510a generated by the plurality of lasers 512 are parallel to each other, parallel to the optical axis of the converging lens 512, transmitted through the converging lens 512, and the plurality of first laser beams 510a are concentrated.
  • the splitting device 520 has different angles between different first laser beams 510a and the optical axis of the spectroscopic device 520. Therefore, the plurality of second laser beams 520a generated by each of the first laser beams 510a are The angle of the optical axis of the beam splitting device 520 is also different, so that the purpose of increasing the angular resolution and the angle of view of the laser radar can be achieved.
  • the plurality of lasers 510 are arranged in a direction perpendicular to a horizontal plane, and the light splitting direction of the light splitting device 520 is perpendicular to a horizontal plane, so that the generation of the plurality of first laser beams 510a can effectively expand the
  • the vertical field of view of the lidar increases the vertical angular resolution of the lidar.
  • the distance from the spectroscopic device 520 to the focal plane of the converging lens 512 is less than half of the focal depth of the converging lens 512. Specifically, the spectroscopic device 520 is located at a focal plane of the converging lens 512.
  • the spectroscopic device 520 is a two-dimensional grating. Specifically, the spectroscopic device 520 is a two-dimensional Daman grating. Moreover, the beam splitting means 520 is adapted to rotate about an adjustment axis of a parallel optical axis. As shown in FIG. 16, a distribution diagram of a spot formed on the target plane before and after the spectroscopic device 520 is rotated about the adjustment axis is shown in the embodiment. It can be seen that the combination of the formation of the plurality of first laser beams and the rotation of the spectroscopic device 520 can effectively improve the angular resolution of the laser radar and effectively expand the field of view of the laser radar.
  • the transmitting device forms a plurality of first laser beams with different propagation directions through the converging lens 512.
  • the transmitting device may further include a plurality of lasers 611, and the light emitting directions of the plurality of lasers 611 intersect at least two or two, that is, the plurality of lasers 611 The light directions are not parallel or different. This method can effectively reduce the number of optical components and simplify the optical path of the laser radar.
  • the method that the spectroscopic device is configured as a Daman grating is only an example.
  • the spectroscopic device may further include a fiber splitter, planar diffraction.
  • Other optical components such as gratings or blazed gratings, or photonic crystal components designed to meet functional requirements.
  • the spectroscopic device may be an optical system composed of a plurality of optical elements (for example, a lens, a beam splitter, or the like).
  • the spectroscopic device may be provided as any optical system or optical component capable of dividing a first laser beam into a plurality of second laser beams having different propagation directions by light refraction, reflection, diffraction or interference.
  • the laser radar further includes a scanning device to ensure The angle of view and angular resolution of the lidar in the horizontal and vertical directions.
  • the present invention also provides a working method of a laser radar.
  • the working method of the laser radar comprises: first performing step S100, providing a laser radar, referring to FIG. 2 to FIG. 4, the laser radar comprising: a transmitting device 110 (shown in FIG. 3), the transmitting device 110 being adapted to generate a first laser beam 110a (shown in FIG. 3); a beam splitting device 120 (shown in FIG. 3), the beam splitting device 120 being adapted to divide the first laser beam 110a into a plurality of second laser beams propagating in different directions 120b (shown in FIG. 3); the second laser beam (shown in FIG. 3) is reflected by the object to be detected (not shown) to form an echo beam 130c (as shown in FIG. 4); the receiving device 130 (As shown in FIG. 3), the receiving device 130 is adapted to receive the echo beam 130c.
  • the spectroscopic device is a Daman grating to prevent the light intensity of a certain one of the plurality of second laser beams from being too small to be detected, and the plurality of second lasers can be effectively ensured.
  • the detection distance of the light beam ensures the successful detection of the echo beam by the receiving device, which is beneficial to improving the detection accuracy and accuracy of the laser radar to be detected.
  • step S200 is executed to enable the transmitting device 110 to generate a first laser beam 110a; the first laser beam 110a is divided into a plurality of second laser beams 120b having different propagation directions through the beam splitting device 120; The second laser beam 120b is reflected by the target to be detected to form an echo beam 130c.
  • the step of causing the transmitting device 110 to generate the first laser beam 110a is to turn on the laser in the transmitting device 110, so that the laser generates the first laser beam 110a.
  • step S300 is performed to receive the echo beam 130c through the receiving device 130.
  • step S300 is performed, and the process of receiving the echo beam 130c by the receiving device includes: the plurality of detectors 131 simultaneously receiving the echo beam 130c to reduce loss and increase a scanning frequency.
  • the step S300 is performed, and the process of receiving the echo beam by the receiving device may further include: the plurality of detectors sequentially receiving the corresponding echo beam.
  • the plurality of detectors can receive the corresponding echo beams according to a certain timing, thereby preventing interference between different echo beams, so as to ensure detection accuracy and accuracy of the laser radar.
  • the division of the first laser beam 110a into the plurality of second laser beams 120b by the spectroscopic device 120 enables a plurality of second laser beams 120b to be obtained by one laser, thereby enabling a large amount of lasers to be saved, thereby enabling the laser radar to be reduced. Cost and installation difficulty.
  • the lidar has a high field of view and angular resolution and is low in cost.
  • FIG. 5 there is shown a schematic structural view of a laser radar provided in a second embodiment of the laser radar operating method of the present invention.
  • the present embodiment is the same as the first embodiment, and the present invention is not described herein again.
  • the present embodiment is different from the foregoing embodiment in that, in the present embodiment, the spectroscopic device 220 has an adjustment shaft 225 parallel to the optical axis; the spectroscopic device 220 is adapted to rotate about the adjustment shaft 225.
  • the rotation of the spectroscopic device 220 can effectively adjust the angular resolution and the angle of view of the laser radar, so that the preset resolution can be set according to different environmental requirements, and the high-angle resolution of the laser radar can be realized.
  • the combination of the large angle of view and the large angle of view is beneficial to improve the detection accuracy and accuracy of the laser radar, and is beneficial to improving the performance of the laser radar in different environments.
  • the spectroscopic device 220 is a two-dimensional grating, and the spectroscopic device 220 has a first grating period in a first direction and a second grating period in a second direction, the first The direction is perpendicular to the second direction; the first grating period is d 1 , the second grating period is d 2 , the wavelength of the first laser beam is ⁇ , and the spectroscopic device 220 is m ⁇ n splitting a grating, m is a number of second laser beams formed along the first direction, n is a number of second laser beams formed along the second direction; and the process of rotating the spectroscopic device 220 about the adjustment axis 225
  • the range of the angle at which the spectroscopic device 220 rotates is: To
  • Reasonably adjusting the range of rotation angle of the spectroscopic device 220 can not only increase the angular resolution of the laser radar, but also can match the angle between adjacent second laser beams, thereby improving the vertical direction of the second laser beam.
  • the uniformity of distribution is conducive to the improvement of the performance of the laser radar.
  • the spectroscopic device may also be configured as a one-dimensional grating.
  • the spectroscopic device is a one-dimensional grating
  • the spectroscopic device has a first grating period in a first direction; the first grating period is d, the wavelength of the first laser beam is ⁇ , and the spectroscopic device is a m ⁇ 1 split grating, m is a number of splitting of the laser beam along the first direction; in a process of rotating the spectroscopic device around the adjustment axis, the angle of rotation of the spectroscopic device is less than Where ⁇ is the preset angle of view.
  • the process of rotating the spectroscopic device around the adjustment axis reasonably controls the angle of rotation of the spectroscopic device, so that the angle of view can be made larger than the preset angle of view ⁇ , thereby ensuring that the laser radar has a higher angular resolution.
  • Lidar has a large field of view.
  • the preset viewing angle ⁇ is greater than or equal to 5°.
  • FIG. 9 there is shown a schematic structural view of a laser radar provided in a third embodiment of the laser radar operating method of the present invention.
  • the laser radar further includes: a galvanometer, the galvanometer includes a first reflecting surface, and the first reflecting surface is adapted to reflect the second a laser beam; the galvanometer has a vibration rotation axis, and the galvanometer is adapted to rotate about the vibration rotation axis, and an angle between the vibration rotation axis and a normal line of the first reflection surface is greater than zero.
  • step 200 is performed to enable the transmitting device to generate a first laser beam.
  • step 220 is performed.
  • the galvanometer mirror changes the propagation direction of the second laser beam reflected from the galvanometer.
  • the combination of the galvanometer 450 and the spectroscopic device 420 can obtain a larger angle of view through a smaller galvanometer 450 angle, so that the rotation angle of the galvanometer 450 can be effectively reduced under the same viewing angle requirement.
  • the rotation period of the small galvanometer 450 is beneficial to improve the scanning frame rate of the laser radar.
  • the light splitting device 420 is a grating
  • the light splitting device 420 has a first grating period in a first direction
  • the second laser beam reflected by the galvanometer is in a first direction.
  • the minimum angle between them is ⁇ 1
  • the scanning rotation axis hangs in the first direction. Therefore, during the rotation of the galvanometer, the galvanometer rotation angle is greater than or equal to ⁇ 1 /2.
  • the smaller rotation angle of the galvanometer 450 can effectively shorten the vibration period of the galvanometer 450, thereby facilitating the scanning frame rate of the laser radar.
  • FIG. 15 there is shown a schematic structural view of a laser radar provided in a fourth embodiment of the laser radar operating method of the present invention.
  • the present embodiment is the same as the foregoing embodiment, and the present invention is not described herein again.
  • the present embodiment is different from the foregoing embodiment in that, in this embodiment, the transmitting device is adapted to simultaneously generate a plurality of first laser beams having different propagation directions; and the transmitting device includes a plurality of lasers.
  • step S200 the step of causing the transmitting device 510 to generate the first laser beam 510a includes turning on at least one laser to generate at least one first laser beam according to a preset resolution.
  • the spectroscopic device 520 can divide each of the first laser beams 510a into a plurality of second laser beams 520b, and the different propagation directions of the first laser beams 510 are formed by being split by the spectroscopic device 520.
  • the plurality of second laser beams 520b travel in different directions.
  • the more the number of lasers is turned on the higher the energy consumption of the laser radar, the higher the compliance of the laser radar optical system, so according to the preset resolution, the number of the turned-on lasers is reasonably set and the reasonably selected is turned on.
  • the laser can improve the utilization of the second laser beam under the premise of ensuring the resolution requirement, effectively control the energy consumption of the laser radar, effectively reduce the compliance of the laser radar optical system, and save energy. Extending the use time is beneficial to reduce the loss and prolong the service life, and is beneficial to achieve both angular resolution and energy consumption control.

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Abstract

一种激光雷达及其工作方法，通过分光装置（120，220，420，520）将第一激光光束（110a，510a）分为多束第二激光光束（120b，520b），能够通过一个激光器（10，510，511，512，611）获得多束第二激光光束（120b，520b），从而能够大量节约激光器（10，510，511，512，611）的数量，进而能够降低激光雷达的成本及安装难度。激光雷达具有较高的视场角和角分辨率，且成本低。

Description

激光雷达及其工作方法
本申请要求2018年1月15日提交中国专利局、申请号为201810036235.4、发明名称为“激光雷达及其工作方法”、2018年1月17日提交中国专利局、申请号为201810045754.7、发明名称为“激光雷达及其工作方法”以及2018年1月17日提交中国专利局、申请号为201810045703.4、发明名称为“激光雷达及其工作方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及光电探测领域，尤其涉及一种激光雷达及其工作方法。
背景技术
激光雷达是一种常用的测距传感器，具有探测距离远、分辨率高、受环境干扰小等特点，广泛应用于智能机器人、无人机、无人驾驶等领域。激光雷达的工作原理与微米波雷达的工作原理类似，都是利用光波往返于雷达和目标之间所用的时间来评估距离的大小。
一开始的激光雷达是单线激光雷达，也就是只有一个激光器和探测器，其扫描的目标范围有限，容易造成检测目标的缺失。为了弥补单线激光雷达的缺点，多线激光雷达越来越成为研究和商用的焦点。多线激光雷达采用多个激光器和相应的探测器在垂直方向进行排列，增加了垂直方向上的探测范围。
然而，现有的多线雷达具有成本高，且安装难度大的缺点。
发明内容
本发明解决的问题是提供一种激光雷达及其工作方法，能够降低激光雷达装置的成本，且安装简单。
本发明提供一种激光雷达，包括：发射装置，所述发射装置适宜于产生第一激光光束；分光装置，所述分光装置适宜于将第一激光光束分为沿不同方向传播的多个第二激光光束；至少部分所述第二激光光束经待探测目标反射形成回波光束；接收装置，所述接收装置适宜于接收所述回波光束。
可选的，所述分光装置具有光轴，垂直所述光轴的平面为目标平面；所述分光装置还适宜于使所述多个第二激光光束在所述目标平面内所成光斑疏密分布。
可选的，在所述目标平面内，所述第二激光光束所形成光斑沿远离所述光轴的方向分布密度逐渐减小。
可选的，所述分光装置具有与光轴平行的调节轴；所述分光装置适宜于绕所述调节轴旋转以改变所述多个第二激光光束的传播方向。
可选的，所述分光装置为光栅或光纤分束器。
可选的，所述分光装置为达曼光栅。
可选的，所述分光装置为一维光栅，所述分光装置具有沿第一方向的第一光栅周期；所述第一光栅周期为d，所述第一激光光束的波长为λ，所述分光装置为m×1分束的光栅，m为沿所述第一方向的激光光束的分束个数；所述分光装置绕所述调节轴旋转的角度小于
Figure PCTCN2018081367-appb-000001
其中，α为预设视场角。
可选的，所述分光装置的第一光栅周期在47μm到57μm范围内；所述第一激光光束的波长在895nm到915nm范围内。
可选的，所述分光装置为二维光栅，所述分光装置具有沿第一方 向的第一光栅周期和沿第二方向的第二光栅周期，所述第一方向与第二方向垂直；所述第一光栅周期为d 1，所述第二光栅周期为d 2，所述第一激光光束的波长为λ，所述分光装置为m×n分束的光栅，m为沿所述第一方向所形成第二激光光束个数，n为沿所述第二方向所形成第二激光光束个数；所述分光装置绕所述调节轴旋转的角度在
Figure PCTCN2018081367-appb-000002
到
Figure PCTCN2018081367-appb-000003
范围内。
可选的，所述分光装置的第一光栅周期在47μm到57μm范围内；所述第一激光光束的波长在895nm到915nm范围内；所述第二光栅周期在47μm到57μm范围内。
可选的，所述发射装置具有与所述第一激光光束传播方向相交的扫描旋转轴，所述发射装置适宜于绕所述扫描旋转轴旋转；所述分光装置的光轴与所述扫描旋转轴的夹角大于0°，且小于或等于90°。
可选的，所述分光装置具有至少一个与光轴垂直的分光方向，所述分光方向与所述光轴所在平面为分光平面；所述多个第二激光光束在至少一个所述分光平面上的投影相互错开；所述分光方向与所述扫描旋转轴的夹角为大于或等于0°，且小于90°。
可选的，所述分光装置为光栅，所述分光装置具有沿第一方向的第一光栅周期；所述分光方向为所述第一方向。
可选的，还包括：振镜，所述振镜包括第一反射面，所述第一反射面适宜于反射所述第二激光光束；所述振镜具有振动旋转轴，所述振镜适宜于绕所述振动旋转轴旋转，所述振动旋转轴与所述第一反射面的法线之间的夹角大于零。
可选的，所述分光装置为一维光栅，所述多个第二激光光束位于同一平面内；投射至所述第一反射面的多个第二激光光束所在平面为传播平面，所述第一反射面与传播平面具有交线，所述振动旋转轴与所述交线之间的夹角大于0°。
可选的，所述发射装置具有与所述第一激光光束传播方向相交的扫描旋转轴，所述发射装置适宜于绕所述扫描旋转轴旋转；所述振动旋转轴与所述扫描旋转轴之间的夹角大于0°。
可选的，还包括：准直透镜，所述准直透镜适宜于对多个第二激光光束进行准直处理，使多个第二激光光束的传播方向平行；聚焦透镜，所述聚焦透镜适宜于将经过准直处理的第二激光光束会聚至所述振镜的第一反射面。
可选的，还包括：半透半反镜，所述半透半反镜适宜于使至少部分所述第二激光光束透过，并入射至所述振镜的第一反射面；所述半透半反镜包括第二反射面，所述第二反射面适宜于将经过振镜反射回的回波光束反射至所述接收装置中。
可选的，还包括：接收会聚透镜，用于将经所述半透半反镜出射的回波光束会聚至所述接收装置中；所述接收装置与接收会聚透镜焦点之间的距离小于接收会聚透镜焦深的一半。
可选的，所述发射装置适宜于同时产生多个传播方向不同的第一激光光束。
可选的，所述发射装置包括多个激光器，所述多个激光器的出光方向至少两两相交。
可选的，所述发射装置包括：多个激光器，所述多个激光器的出光方向相互平行；会聚透镜，所述会聚透镜适宜于使多个激光器产生的第一激光光束会聚至所述分光装置；所述分光装置到所述会聚透镜焦平面的距离小于会聚透镜焦深的一半。
相应的，本发明还提供一种激光雷达的工作方法，包括：提供激 光雷达，所述激光雷达包括：发射装置，所述发射装置适宜于产生第一激光光束；分光装置，所述分光装置适宜于将第一激光光束分为沿不同方向传播的多个第二激光光束；所述第二激光光束经待探测目标反射形成回波光束；接收装置，所述接收装置适宜于接收所述回波光束；使所述发射装置产生第一激光光束；所述第一激光光束经过所述分光装置，分为多个传播方向不相同的第二激光光束；至少部分所述第二激光光束到达所述待探测目标后反射形成回波光束；通过所述接收装置接收所述回波光束。
可选的，所述分光装置具有与光轴平行的调节轴；所述分光装置适宜于绕所述调节轴旋转；使所述发射装置产生第一激光光束，所述第一激光光束经所述分光装置分为所述多个第二激光光束之后，根据预设分辨率，旋转所述分光装置。
可选的，所述分光装置为一维光栅，所述分光装置具有沿第一方向的第一光栅周期；所述第一光栅周期为d，所述第一激光光束的波长为λ，所述分光装置为m×1分束的光栅，m为沿所述第一方向的激光光束的分束个数；绕所述调节轴旋转所述分光装置的过程中，所述分光装置旋转的角度小于
Figure PCTCN2018081367-appb-000004
其中，α为预设视场角。
可选的，所述分光装置为二维光栅，所述分光装置具有沿第一方向的第一光栅周期和沿第二方向的第二光栅周期，所述第一方向与第二方向垂直；所述第一光栅周期为d 1，所述第二光栅周期为d 2，所述第一激光光束的波长为λ，所述分光装置为m×n分束的光栅，m为沿所述第一方向所形成第二激光光束个数，n为沿所述第二方向所形成第二激光光束个数；绕所述调节轴旋转所述分光装置的过程中，所 述分光装置旋转的角度的范围为：
Figure PCTCN2018081367-appb-000005
到
Figure PCTCN2018081367-appb-000006
可选的，所述激光雷达还包括：振镜，所述振镜包括第一反射面，所述第一反射面适宜于反射所述第二激光光束；所述振镜具有振动旋转轴，所述振镜适宜于绕所述振动旋转轴旋转，所述振动旋转轴与所述第一反射面的法线之间的夹角大于零；使所述发射装置产生第一激光光束，所述第一激光光束经所述分光装置分为所述多个第二激光光束之后，旋转所述振镜，改变自振镜反射出的第二激光光束的传播方向。
可选的，所述分光装置为光栅，所述分光装置具有沿第一方向的第一光栅周期，所述振镜反射出的第二激光光束在沿第一方向之间的最小夹角为θ1，所述扫描旋转轴垂于所述第一方向；旋转所述振镜的过程中，使振镜旋转角度大于或等于θ 1/2。
可选的，所述发射装置适宜于同时产生多个传播方向不同的第一激光光束；所述发射装置包括多个激光器；使所述发射装置产生第一激光光束的步骤包括，根据预设分辨率，开启至少一个激光器以产生至少一个第一激光光束。
可选的，所述接收装置包括多个探测器，各探测器分别适宜于接收相应的第二激光光束经待探测目标反射的回波光束；通过所述接收装置接收所述回波光束的过程包括：所述多个探测器同时接收所述回波光束；或者，所述多个探测器依次接收所对应的回波光束。
可选的，所述分光装置为达曼光栅。
与现有技术相比，本发明的技术方案具有以下优点：
本发明技术方案提供的激光雷达包括分光装置，所述分光装置能够将所述第一激光光束分为多个沿不同方向传播的第二激光光束。沿不同方向传播的第二激光光束能够对不同方位的待探测目标进行检测，从而能够增加所述激光雷达的视场角和角分辨率；通过分光装置将第一激光光束分为多束第二激光光束能够通过一个激光器获得多束第二激光光束，从而能够大量节约激光器的数量，进而能够降低所述激光雷达的成本及安装难度。所述激光雷达具有较高的视场角和角分辨率，且成本低。
本发明可选方案中，所述分光装置还适宜于使所述多个第二激光光束在垂直所述光轴的平面内呈疏密分布；从而能够在所述第二激光光束数量不增加的情况下，有效提高部分垂直所述光轴的平面内角分辨率，有利于提高所述多个第二激光光束的利用率，有利于实现高分辨率和低成本的兼顾。
本发明可选方案中，在垂直所述光轴的平面内，所述分光装置适宜于使所述多个第二激光光束沿远离所述光轴的方向分布密度逐渐减小。当所述光轴平行于水平面时，所述多个第二激光光速的疏密分布，能够使更多的第二激光光束聚集于水平线和靠近地面，使所述激光雷达在车辆行驶过程中障碍物所处位置具有较高的角分辨率，能够有效提高所述激光雷达对障碍物识别的准确性，有利于拓展所述激光雷达在车辆上的应用前景。
本发明可选方案中，所述分光装置具有与光轴平行的调节轴，所述分光装置适宜于绕所述调节轴选旋转以改变所述多个第二激光光束的传播方向。通过所述分光装置的旋转，能够改变所述多个第二激光光束的传播方向，以达到调节所述激光雷达垂直角分辨率的目的；而且分光装置的旋转，还能够使在垂直方向上部分重叠的第二激光光束位置错开，从而达到增大垂直角分辨率的目的；因此所述将所述分 光装置设置为可旋转的做法，能够实现不同环境需求下，所述激光雷达在高角分辨率和大视场角的平衡，有利于提高所述激光雷达的探测精度和准确度。
本发明可选方案中，所述分光装置为光栅或光纤分束器。将所述分光装置设置为光栅的做法，不仅能够使所述分光装置实现分光的作用以减小激光器的数量，还能够使所述第二激光光束呈现疏密的非均匀分布，能够兼顾低成本、高角分辨率以及大视场角，有利于实现成本控制和性能改善的兼顾。
本发明可选方案中，所述分光装置为达曼光栅。达曼光栅是一种能将单一光束分成若干等强度光束的衍射光学元件，因此将所述分光装置设置为达曼光栅的做法，能够有效提高所述多个第二激光光束的光强均匀性，能够避免因所述多个第二激光光束中某束光强度过小而难以被探测器检测，能够有效保证所述多个第二激光光束的探测距离，保证所述接收装置对所述回波光束的成功探测，有利于提高所述激光雷达的探测距离，有利于实现高垂直角分辨率和大探测距离的兼顾，有利于提高所述激光雷达对待探测目标的探测精度和准确性。
本发明可选方案中，所述分光装置为一维光栅，所述分光装置绕所述调节轴旋转的角度小于
Figure PCTCN2018081367-appb-000007
合理设置所述分光装置旋转角度，能够使视场角大于预设视场角α，从而能够在保证激光雷达具有较高角分辨率的情况下，使激光雷达上具有较大的视场角。
本发明可选方案中，所述分光装置为二维光栅，所述分光装置绕 所述调节轴旋转的角度范围为
Figure PCTCN2018081367-appb-000008
Figure PCTCN2018081367-appb-000009
合理设置所述分光装置旋转角度，不仅能够增大激光雷达的角分辨率，还能够使相邻第二激光光束的夹角相等，从而提高第二激光光束的分布均匀性，有利于激光雷达性能的改善。
本发明可选方案中，所述发射装置具有扫描旋转轴，所述发射装置适宜于绕所述扫描旋转轴旋转；所述扫描旋转轴的延伸方向与所述分光装置的光轴方向的夹角大于0°，且小于或等于90°。所述发射装置的旋转，能够有效扩大所述激光雷达的扫描范围，有利于激光雷达探测能力的改善和探测范围的扩大。
本发明可选方案中，所述分光装置为光栅；所述分光装置具有至少一个与光轴垂直的分光方向，所述分光方向与所述光轴所在平面为分光平面；所述多个第二激光光束在至少一个所述分光平面上的投影相互错开；所述分光方向与所述扫描旋转轴的夹角为大于或等于0°，且小于90°。通过使所述分光方向与所述扫描旋转轴的夹角为大于或等于0°，且小于90°，能够使所述第二激光光束尽量沿扫描旋转轴的方向错开，从而在有限的第二激光光束数量的前提下，达到提高沿扫描旋转轴方向角分辨率的目的。
本发明可选方案中，所述激光雷达还包括适宜于绕所述振动旋转轴旋转的振镜，所述振镜具有适宜于反射所述第二激光光束的第一反射面。通过所述振镜绕所述振动旋转轴的旋转，能够改变经所述第一反射面反射的第二激光光束的传播方向，从而能够增大所述第二激光 光束的扫描范围、增大激光雷达视场角；而且所述振镜的旋转只要使旋转前第二激光光束之间最小夹角范围内均被扫描，获取的视场角便能够达到第二激光光束之间的最大夹角范围，因此，所述振镜与分光装置的组合能够通过较小的振镜转角获取较大的视场角，所以在相同的视场角要求下，能够有效减小振镜的旋转角度，减小振镜的旋转周期，从而有利于提高激光雷达的扫描帧频。
本发明可选方案中，所述分光装置为二维光栅；将二维光栅和所述振镜组合使用，能够有效扩大所述多个第二激光光束的传播范围，有利于增加激光雷达沿各方向的角分辨率和视场角。
本发明可选方案中，所述激光雷达好包括半透半反镜，以分离回波光束和第二激光光束，从而防止第二激光光束对接收装置的干扰，降低第二激光光束对检测结果的影响，提高所述激光雷达的精度；还能够利用所述半透半反镜实现光路重叠，从而缩短所述激光雷达的光路，能够有效减小光学***体积，有利于减小所述激光雷达的体积。
本发明可选方案中，所述发射装置适宜于同时产生传播方向不同的第一激光光束。所述分光装置能够使每一个第一激光光束经分为多个第二激光光束，因此多个传播不同的第一激光光束的产生能够增加所形成第二激光光束的数量，且由传播方向不同的第一激光光束产生的第二激光光束传播方向均不相同，从而能够进一步增加激光雷达的角分辨率。
本发明可选方案中，所述发射装置包括多个出光方向相互平行的激光器和会聚透镜，所述会聚透镜适宜于使多个激光器产生的第一激光光束会聚至所述分光装置；所述会聚透镜能够使出光方向相同的多个激光器产生会聚至所述分光装置的第一激光光束，既能够降低所述多个激光器的安装难度，又能够产生多个传播方向不同的第一激光光束，从而能够有效降低所述多个激光器的安装难度，有利于降低安装成本，还能够有效提高所述第一激光光束光路的准确性，有利于提高所述激光雷达的探测准确性和探测精度。
本发明技术方案提供的激光雷达工作方法中，通过所述分光装置将第一激光光束分为多束第二激光光束能够通过一个激光器获得多束第二激光光束，从而能够大量节约激光器的数量，进而能够降低所述激光雷达的成本及安装难度。所述激光雷达具有较高的视场角和角分辨率，且成本低。
本发明的可选方案中，形成所述多个第二激光光束之后，根据预设垂直分辨率，旋转所述分光装置以改变所述多个第二激光光束的传播方向。通过所述分光装置的旋转，能够改变所述多个第二激光光束的传播方向，以达到调节所述激光雷达垂直角分辨率的目的，能够实现不同环境需求下，所述激光雷达在高角分辨率和大视场角的平衡，有利于提高所述激光雷达的探测精度和准确度。
本发明可选方案中，所述发射装置具有多个激光器；因此使所述发射装置产生第一激光光束的步骤中，可以根据预设的垂直分辨率，开启至少一个激光器以产生至少一个第一激光光束。所述激光雷达的能耗与开启的激光器数量相关，因此通过对开启激光器数量的控制以优化所述激光雷达的能耗，从而实现角分辨率和节能的兼顾。
附图说明
图1是一种多线激光雷达激光器的结构示意图；
图2是本发明激光雷达第一实施例的立体结构示意图；
图3是图2所示激光雷达实施例的发射部分光路示意图；
图4是图2所示激光雷达实施例的接收部分光路示意图；
图5是本发明激光雷达第二实施例的部分结构示意图；
图6是在所述第一方向与y正方向夹角为0时，图5所示激光雷达实施例在目标平面上所形成光斑的示意图；
图7是在所述第一方向与y方向锐角夹角为
Figure PCTCN2018081367-appb-000010
时，图5所示激 光雷达实施例在目标平面上所形成光斑的示意图；
图8是本发明激光雷达第三实施例在目标平面上所形成光斑的示意图；
图9是本发明激光雷达第四实施例的光路示意图；
图10是图9所示激光雷达实施例中区域41中第一激光光束和第二激光光束的放大光路示意图；
图11是图9所示激光雷达实施例中回波光束的放大光路示意图；
图12是图9所示激光雷达实施例中，在振镜静止时所述多个第二激光光束在所述目标平面上所形成光斑的示意图；
图13是图9所示激光雷达实施例中，所述振镜450旋转θ＝dy/4l弧度时所述多个第二激光光束在所述目标平面上所形成光斑的示意图；
图14是图9所示激光雷达实施例中，所述振镜450旋转θ＝-dy/4l弧度时，所述多个第二激光光束在所述目标平面上所形成光斑的示意图；
图15是本发明激光雷达第五实施例的结构示意图；
图16是图15所示激光雷达实施例中所述分光装置绕所述调节轴旋转前后在所述目标平面上所形成光斑的分布示意图；
图17是本发明激光雷达第六实施例的结构示意图。
具体实施方式
激光雷达装置存在诸多问题，例如：成本高、安装难度大。现结合一种激光雷达，分析所述激光雷达成本高、安装难度大的原因。
激光雷达装置主要包括用于发射激光的激光器和用于接收由待检目标反射回的光线的探测器。在激光雷达的工作过程中，激光器向 待检目标发射激光；所发射激光投射至待检目标上之后，被待见目标反射而折返被探测器采集。
传统的激光雷达装置仅包括一个激光器和一个探测器，因此，激光雷达装置仅能同时发射一束激光，从而引起了激光雷达的垂直角分辨率过低的问题。为了提高激光雷达的垂直角分辨率，提出了一种多线激光雷达。
图1是一种多线激光雷达的激光器的结构示意图。
请参考图1，所述多线激光雷达的激光器包括多个用于发射激光的激光器10以及用于使不同位置激光器10发射的激光具有不同的传播方向的透镜20。所述多个激光器10分布于沿垂直于透镜20主光轴(图1中为水平面)的平面内。
每个激光器10发射一束激光光束，每个经透镜20透射的激光光束对应着不同的激光出射角度，从而增加雷达在垂直方向上的分辨率。因此，所述多线激光雷达每个发射角度需要有一个激光器10与其相对应，从而导致激光雷达的成本较高。另外，多线激光雷达的每个激光器10需要在有限的空间内放置在固定的位置，使得安装较困难。
为解决所述技术问题，本发明提供了一种激光雷达及其工作方法，通过分光装置将第一激光光束分为多束第二激光光束能够通过一个激光器获得多束第二激光光束，从而能够大量节约激光器的数量，进而能够降低所述激光雷达的成本及安装难度。所述激光雷达具有较高的视场角和角分辨率，且成本低。
为使本发明的上述目的、特征和优点能够更为明显易懂，下面结合附图对本发明的具体实施例做详细的说明。
参考图2至图4，是本发明激光雷达第一实施例的结构示意图。其中，图2是所述激光雷达实施例的立体结构示意图；图3示出了图2所示激光雷达实施例的发射部分光路示意图。
所述激光雷达包括：发射装置110(如图3所示)，所述发射装 置110适宜于产生第一激光光束110a；分光装置120(如图3所示)，所述分光装置120适宜于将第一激光光束110a分为沿不同方向传播的多个第二激光光束120b；至少部分所述第二激光光束120b经待探测目标反射形成回波光束；接收装置130，所述接收装置适宜于接收所述回波光束。
所述分光装置120能够将所述第一激光光束110a分为多个沿不同方向传播的第二激光光束120b。沿不同方向传播的第二激光光束120b能够对不同方位的待探测目标进行检测，从而能够增加所述激光雷达的视场角和角分辨率；通过分光装置将第一激光光束110a分为多束第二激光光束120b能够通过一个激光器获得多束第二激光光束，从而能够大量节约激光器的数量，进而能够降低所述激光雷达的成本及安装难度。所述激光雷达具有较高的视场角和角分辨率，且成本低。
所述发射装置110作为光源，用于产生第一激光光束110a。
本实施例中，所述激光雷达具有发射接收模块100，所述发射接收模块100包括所述发射装置110、所述分光装置120以及所述接收装置130。
具体的，所述发射接收模块100包括发射结构101和接收装置130，所述发射结构101包括所述发射装置和分光装置120。
如图2所示，本实施例中，所述发射装置110具有与所述第一激光光束110a传播方向相交的扫描旋转轴111，所述发射装置110适宜于绕所述扫描旋转轴111旋转，即所述第一激光光束110a与所述扫描旋转轴111之间的夹角大于零；所以随着所述发射装置110的转动，所述第一激光光束110a的传播方向也会发生变化。所以所述发射装置的旋转，能够有效扩大所述激光雷达的扫描范围，有利于激光雷达探测能力的改善和探测范围的扩大。
本实施例中，所述激光雷达还包括：固定机构102，所述固定机 构102适宜于实现整个所述激光雷达的固定；旋转机构103，所述旋转机构103位于所述发射接收模块100和所述固定机构102之间，所述旋转机构103适宜于实现所述发射接收模块100和所述固定机构102之间的连接。
具体的，所述发射装置110固定于所述发射接收模块100内，所述旋转机构103适宜于使所述发射接收模块100绕所述扫描旋转轴111旋转，从而实现所述发射装置110绕所述扫描旋转轴111的旋转。
本实施例中，所述激光雷达安装于地面，所述激光雷达相对于地面固定。所述扫描旋转轴111垂直于水平面。在其他实施例中，所述激光雷达可以安装于汽车或者飞机上，所述扫描旋转轴可以与水平面斜交。
如图3所示，本实施例中，所述发射装置110产生一个第一激光光束110a。所述发射装置110为1个激光器。具体的，所述发射装置110为固体激光器或者光纤激光器。
此外，本实施例中，所述第一激光光束110a的波长在895nm到915nm范围内，例如为905nm。895nm到915nm范围内的激光为具有较高穿透能力的红外激光，为不可见光，因此将所述第一激光光束110a的波长范围合理设置能够有效降低所述激光雷达对周围环境的干扰，还能够有效改善所述激光雷达的探测距离。
但是本发明其他实施例中，所述发射装置110也可以包括其他类型的激光器；所述第一激光光束也可以是其他波长范围的激光。
所述分光装置120用于实现分光，从而将所述第一激光光束110a分为沿不同方向传播的多个第二激光光束120b。
需要说明的是，本实施例中，所述激光雷达还包括：扩束准直装置140，所述扩束准直装置140设置于所述发射装置110和所述分光装置120之间的第一激光光束110a的光路中。
所述扩束准直装置140适宜于对所述第一激光光束110a进行扩 束和准直，即增加传播相同距离时所述第一激光光束110a的光斑直径，并减小所述第一激光光束110a的发散角。
所述扩束准直装置140能够增加所述第一激光光束110a的光斑直径，从而能够有利于回波光束的接收；所述扩束准直装置140还能够减小所述第一激光光束110a的发散角，从而提高所述第一激光光束110a传播方向控制的精度，有利于提高所述激光雷达的探测精度。具体的，本实施例中，所述扩束准直装置140为望远镜。
所述分光装置120能够将一个第一激光光束110a分为多个第二激光光束120，在增大所述激光雷达角分辨率的前提下，减少激光器的数量，降低激光雷达的成本和装配难度，从而实现性能提高和成本降低的兼顾。
如图3所示，所述分光装置120具有光轴121，所述光轴121的延伸方向与所形成的第二激光光束120b的传播方向相一致；另一方面，所述发射装置110具有扫描旋转轴111，所述分光装置120的光轴121与所述扫描旋转轴111的夹角大于0°，且小于或等于90°，也就是说，所述光轴121与所述扫描旋转轴111相交。
如图3所示，由于所述分光装置120光轴121与所述扫描旋转轴111相交，而且所述扫描旋转轴111与所述第一激光光束110a的传播方向相交，因此随着所述发射装置110的转动，所述第一激光光束110a的传播方向发生变化，所述多个第二激光光束120a的传播方向也会发生变化，从而能够使所述多个第二激光光束120a对一定空间的扫描，能够有效提高所述激光雷达的空间分辨率，有利于所述激光雷达探测能力的改善。
本实施例中，所述光轴121垂直所述扫描旋转轴111，因此能够有效保证所述多个第二激光光束120a对垂直所述扫描旋转轴111平面内360°范围内的扫描，从而能够有效扩大所述激光雷达在垂直所述扫描旋转轴111平面内的视场角，有利于所述激光雷达探测范围的扩大。
此外，本实施例中，所述分光装置120具有与光轴121垂直的分光方向124，所述分光方向124与所述光轴121所在平面为分光平面(图中未示出)；所述多个第二激光光束120b在所述分光平面上的投影相互错开；所述分光方向124与所述扫描旋转轴111的夹角为大于或等于0°，且小于90°，即避免所述分光方向124垂直所述扫描旋转轴111。
避免所述分光方向124垂直所述扫描旋转轴111设置，能够使所述多个第二激光光束120b形成一定的发散角，从而有效提高所述激光雷达的垂直角分辨率，进而有利于改善所述激光雷达的探测能力。所以所形成的多条第二激光光束120b中包括若干传播方向与所述扫描旋转轴111的夹角不相同的第二激光光束120b，能够增加所述激光雷达的平行于所述扫描旋转轴111的角分辨率和视场角。在其他实施例中，所述多条第二激光光束中包括若干传播方向与旋转轴的夹角相同的第二激光光束。
本实施例中，所述分光方向124与所述扫描旋转轴111相互平行，能够有效增大所述多个第二激光光束120b的发散角，从而提高所述激光雷达的垂直视场角，有利于扩大所述激光雷达的探测范围。
具体的，所述激光雷达安装于地面，所述扫描旋转轴111垂直于水平面，因此所述分光装置120的光轴121平行水平面，所述发射装置110绕垂直水平面的所述扫描旋转轴111旋转，从而使所述多个第二激光光束向水平面内各个方向传播，能够有效增大所述激光雷达沿水平方向的视场角及水平角分辨率。
特别是当所述激光雷达应用于汽车等交通设备时，较大的水平方向视场角以及较大的水平角分辨率，能够有效扩大所述激光雷达的探测范围，有利于提高所述激光雷达对交通设备周围障碍物的探测成功率。
此外，所述分光方向124与所述扫描旋转轴111平行，因此所述分光方向垂直于水平面，因此所述分光装置120能够使一个第一激光 光束110a形成多个沿垂直水平面方向错开的第二激光光束120b，从而能够在不增加激光器数量，不减小激光雷达垂直视场角的情况下，提高所述激光雷达的垂直角分辨率，进而能够有效提高所述激光雷达对交通设备周围障碍物的探测成功率，有利于实现大视场角、高角分辨率、低制造成本的兼顾，有利于使所述激光雷达更适宜于交通领域的应用。
继续参考图3，垂直所述光轴121的平面为目标平面123，所述分光装置120还适宜于使所述多个第二激光光束120b在所述目标平面120内所成光斑疏密分布，也就是说，所述多个第二激光光束120b投射至所述目标平面123上后所形成光斑为非均匀分布。
将所述分光装置120设置为使所述第二激光光束120b在所述目标平面123内形成光斑非均匀分布的做法，能够在不增加所述第二激光光束120b数量的前提下，使更多的第二激光光束120b集中于所述目标平面123的部分面积上，从而提高所述分光装置120与所述目标平面123之间部分空间的第二激光光束120b密度，从而达到提高部分空间角分辨率、提高第二激光光束120b利用率的目的。
另一方面，局部空间角分辨率的提高、第二激光光束120b利用率的提高，降低无探测功能的第二激光光束120b的数量，在保证局部角分辨率的前提下，能够有效减小激光器的数量，有利于降低制造成本和装配难度，还能够减小***负荷，有利于提高扫描频率，有利于改善所述激光雷达的性能。
本实施例中，在所述目标平面123内，所述分光装置120使所述多个第二激光光束120b所形成光斑沿远离所述光轴121的方向分布密度逐渐减小，也就是说，所述分光装置120能够使更多的第二激光光束120b集中于所述光轴121附近，使靠近所述光轴121位置所述第二激光光束120b的数量较多、密度较大；使远离所述光轴121位置所述第二激光光束120b的数量较少、密度较小。
使更多的第二激光光束120b集中于所述光轴121附近的做法， 能够在不增加设备成本、装配难度的前提下，有效提高所述激光雷达在所述光轴121附近空间的角分辨率，有利于提高所述第二激光光束120b的利用率，有利于实现制造成本和探测性能的兼顾。
本实施例中，所述发射装置110能够绕所述扫描旋转轴111旋转，所述多个第二激光光束120b传播方向与所述扫描旋转轴111相交，因此在垂直所述扫描旋转轴111方向上，所述激光雷达的角分辨率与所述第二激光光束120b的传播方向变化速率相关，即与所述发射装置110的旋转速率相关。
在所述扫描旋转轴111平行的平面内，所述激光雷达的视场角大小、角分辨率高低与所述第二激光光束120b的数量以及相邻第二激光光束之间的间隔相关，与所述分光方向与所述扫描旋转轴111方向之间的夹角大小相关。
本实施例中，所述分光方向124与所述扫描旋转轴111方向相互平行，能够在不增加第二激光光束120b数量的情况下，尽可能增大所述多个第二激光光束120b的发散角，以获得较大的垂直视场角；而使更多的第二激光光束120b集中于所述光轴121附近，能够在保证较大垂直视场角的前提下，减小所述光轴121附近相邻所述第二激光光束120b之间的间隔，以达到提高垂直角分辨率的目的。
具体的，本实施例中，所述激光雷达安装于地面，所述扫描旋转轴111垂直于水平面，所述光轴121平行水平面，所述分光方向124垂直于水平面，使更多的第二激光光束120b集中于所述光轴121附近的做法，能够有效提高所述激光雷达在水平面附近空间的垂直角分辨率，有利于提高所述激光雷达对水平面附近障碍物的探测成功率。
特别是当所述激光雷达应用于汽车的交通设备时，待探测目标通常为行人、车辆等靠近底面附近的障碍物，因此使更多的第二激光光束120b集中于所述光轴121附近的做法，也就是使更多的第二激光光束120b集中于地面附近，从而在不增加制造成本、装配难度，不减小垂直视场角的前提下，提高所述激光雷达的垂直角分辨率，能够 使所述多个第二激光光束120b的空间分布更适宜于真实的交通环境，有利于使所述激光雷达更适宜于交通领域的应用。
另一方面，水平面、底面附件的垂直角分辨率的增大，能够在保证垂直角分辨率的前提下，减小激光器的数量，有利于降低制造成本和装配难度，还能够减小***负荷，有利于提高扫描频率，有利于改善所述激光雷达的扫描准确性。
本实施例中，所述分光装置120为光栅。
光栅是通过光线的衍射和干涉作用将一个所述第一激光光束110a分为所述多个第二激光光束120b。具体的，所述分光装置120为光栅，所述分光装置120具有沿第一方向的第一光栅周期；所述分光装置120的分光方向124包括所述第一方向。
具体的，光栅原理公式为：
dsin(θ)＝mλ
其中，d为光栅周期；m为衍射级次；λ为第一激光光束110a的波长，θ为所述第二激光光束120b与光栅平面法线之间的夹角。所以根据所述光栅原理公式可以知道：sin(θ)＝mλ/d。
而当角度较小时，角度的正弦函数值与相应的角度值相近；当角度较小时，角度的正弦函数值小于相应的角度值，且角度越大，角度的正弦函数值与相应的角度值之间的差值越大。
因此所述第二激光光束120b衍射级数m较小时，所述第二激光光束120b与光栅平面法线之间夹角θ较小，所述夹角θ与所述第二激光光束120b的衍射级数m成线性的关系；所述第二激光光束120b衍射级数m较大时，所述第二激光光束120b与光栅平面法线之间夹角θ较大，所述夹角θ大于所述夹角θ的正弦函数值，更大于所述第二激光光束120b衍射级数m的线形关系。
所以随着衍射级数m的增大，所述第二激光光束120b与光栅平 面法线之间夹角θ，不同级数第二激光光束120b与光栅平面法线之间夹角θ的差值逐渐增大，即相邻第二激光光束120b之间的夹角逐渐增大，也就是说，所述第二激光光线120b更集中于所述光栅平面法线的方向。
如图3所示，所述分光装置120设置为光栅时，所述光栅平面法线的方向与所述光轴121相平行，因此，将所述分光装置120设置为光栅的做法，能够使更多的第二激光光线120b集中于所述光轴121。
所以将所述分光装置120设置为光栅的做法，不仅能够使所述分光装置120实现分光的作用以减小激光器的数量，还能够使所述第二激光光束120b呈现疏密的非均匀分布，使所述第二激光光线120b更集中于所述光轴121的方向，从而能够兼顾低成本、高角分辨率以及大视场角，有利于实现成本控制和性能改善的兼顾。
此外，通过光栅进行分光，光学元件数量较少，光路结构简单，有利于提高所述激光雷达的光路精度；而且光栅制作工艺成熟，制作成本较低，将所述分光装置120设置为光栅，也能够有效降低所述分光装置120的制作成本。
具体的，所述分光装置120为达曼光栅。
达曼光栅是一种具有不等间距、周期重复的相位光栅。达曼光栅是一种能将单一光束分成若干等强度光束的衍射光学元件。因此将所述分光装置120设置为达曼光栅的做法，能够将一个所述第一激光光束110a分为沿不同方向、光强相等的多个第二激光光束120b，能够有效提高所述多个第二激光光束120b的光强均匀性，能够避免因所述多个第二激光光束120b中某束光强度过小而难以被探测，能够有效保证所述多个第二激光光束120b的探测距离，保证所述接收装置130对所述回波光束的成功探测，有利于提高所述激光雷达的探测距离，有利于实现高垂直角分辨率和大探测距离的兼顾，有利于提高所述激光雷达对待探测目标的探测精度和准确性。
具体的，达曼光栅包括多个交替排列的第一区和第二区。光束透射达曼光栅的过程中，经所述第一区透射的光束所延迟的相位与经所述第二区透射的光束的所延迟相位之间存在π弧度的差值。相邻第一区之间的距离或相邻第二区之间的距离为光栅的光栅周期。达曼光栅的多个第一区的宽度不相同，多个第二区的宽度不相同。达曼光栅通过合理设计所述光栅周期、第一区宽度和第二区宽度使得所产生的多束第二激光光束的光强相等。
本实施例中，所述分光装置120为一维达曼光栅，因此所述分光装置120中，第一区和第二区为延伸方向平行的条形，所述第一区和所述第二区的延伸方向垂直所述分光方向；而所述分光方向124垂直于水平面，所以所述第一区和所述第二区的延伸方向平行于水平面。
此外，经达曼光栅分束所形成的等强度光束数量越多，即一个所述第一激光光束110a经所述分光装置120分束所形成第二激光光束120b的数量越多，所述激光雷达的视场角越大、角分辨率越高
本实施例中，所述分光装置120为一维达曼光栅，一维达曼光栅设计、制造成本较低，能够有效控制所述激光雷达的制造成本。具体的，所述分光装置120为1×9分束的一维达曼光栅。本发明其他实施例中，所述分光装置120还可以设置为1×5分束、1×15分束、1×32分束或1×64分束的达曼光栅。
此外，根据光栅原理方程，所述第二激光光束120b与光栅平面法线之间夹角θ的大小与衍射级次m、第一激光光束110a的波长λ以及光栅周期d相关。因此第一激光光束110a的波长λ一定，所述分光装置120的参数确定的情况下，不同级次的第二激光光束120b与光栅平面法线之间夹角θ不相同，即能够得到多束沿不同方向传播的第二激光光束120b。
所以本实施例中，所述一维达曼光栅的光栅周期在47μm到57μm范围内，例如52μm。具体的，本实施例中，所述分光装置120的相位转折点为0.06668，0.12871，0.28589，0.45666，0.59090。
需要说明的是，本发明其他实施例中，所述分光装置还可以设置为二维达曼光栅，二维达曼光栅能够使所述第二激光光束的水平发射角度和垂直发射角度不相同，从而能够增加激光雷达的垂直角分辨率和水平角分辨率。水平方向为平行于水平面的方向，所述垂直方向垂直于水平面的方向。
继续参考图2、图3和图4，其中图4示出了图2所示激光雷达实施例的接收部分光路示意图。
所形成的多个第二激光光束120b从所述发射结构101中出射，至少部分所述第二激光光束120b投射至待探测目标上，经待探测目标反射形成回波光束130c；所述接收装置130接收所述回波光束130c；根据所接收回波光束130c分析获得所述待探测目标的信息。
如图4所示，本实施例中，所述接收装置130包括多个探测器131，各探测器131分别适宜于接收相应的第二激光光束经待探测目标反射的回波光束130c。具体的，所述探测器131为光电二极管或光电倍增管、雪崩光电二极管或红外和可见光探测器件等。
此外，所述接收装置130还包括：接收会聚透镜132，所述接收会聚透镜132适于将所述回波光束130c会聚至所述探测器131，所述分光装置131到所述接收会聚透镜132焦平面的距离小于所述接收会聚透镜焦132焦深的一半。具体的，本实施例中，所述分光装置131位于所述接收会聚透镜132的焦平面处。
传播方向相同的第二激光光束120b所形成的回波光束130c经所述接收会聚透镜132透射，会聚至同一探测器131表面；传播方向不相同的第二激光光束120b所形成的回波光束130c经所述接收会聚透镜132透射，会聚至不同的探测器131，因此根据所述回波光束130c的传播方向，能够获得所述待探测目标的方位。
所述接收装置130与所述发射结构101分立。所述接收装置130与所述发射结构101的分立设置，能够避免所述回波光束130c经过 所述分光装置120，从而避免分光装置120对所述回波光束130c传播方向的影响，有利于确定待探测目标的位置。
此外，本实施例中，所述接收装置130还包括分析装置(图中未示出)。所述探测器131接收所述回波光束130c之后，将所述回波光束130c的光信号转化为电信号；所述分析装置用于对所述电信号进行分析从而获取所述待探测目标的位置。
参考图5，示出了本发明激光雷达第二实施例的部分结构示意图。
本实施例与第一实施例相同之处，本发明不再赘述。本实施例与前述实施例不同之处，首先在于，本实施例中，所述分光装置220具有与光轴(图中未示出)平行的调节轴225；所述分光装置220适宜于绕所述调节轴225旋转以改变所述多个第二激光光束的传播方向。
通过所述分光装置220的旋转，能够改变所述多个第二激光光束的传播方向，以达到调节所述激光雷达角分辨率的目的；而且分光装置220的旋转，还能够使在部分重叠的第二激光光束位置错开，从而达到增大角分辨率的目的；因此所述将所述分光装置220设置为可旋转的做法，能够实现不同环境需求下，所述激光雷达在高角分辨率和大视场角的平衡，有利于提高所述激光雷达的探测精度和准确度。
此外，本实施例中，所述分光装置220为二维光栅。所以所述分光装置220具有沿第一方向的第一光栅周期d 1和沿第二方向的第二光栅周期d 2，所述第二方向与所述第一方向相垂直。具体的，所述分光装置220为二维达曼光栅。
二维达曼光栅的第一区和第二区沿第一方向和第二方向呈矩阵式排列。所述第一光栅周期d 1为沿第一方向上相邻第一区之间的距离，或者沿第一方向上相邻第二区之间的距离；所述第二光栅周期d 2为沿第二方向上相邻第一区之间的距离，或者沿第二方向上相邻第二区之间的距离。达曼光栅的多个第一区的宽度不相同，多个第二区的宽度亦不相同。达曼光栅通过合理设计所述第一光栅周期d 1、第二光栅周 期d 2、第一区宽度和第二区宽度使得所产生的多个第二激光光束的光强相等。
需要说明的是，根据光栅原理方程，将所述分光装置220设置为光栅时，经所述分光装置220分束所形成的多个第二激光光束的出射角度与所述第一激光光束的波长λ以及所述分光装置220的参数相关。具体的，本实施例中，所述第一激光光束的波长λ在895nm到915nm范围内，例如905nm。所述分光装置220的第一光栅周期d 1在47μm到57μm范围内，例如52μm，第二光栅周期d 2在47μm到57μm范围内，例如52μm。
具体的，如图5所示，为了分析清晰，在所述分光装置220上建立直角坐标系：相互垂直的x方向和y方向位于所述分光装置220的光栅平面内，以所述分光装置220光栅平面的法向为z方向。所以z方向平行于光轴方向。
本实施例中，所述激光雷达安装于地面，所述光轴平行于水平面，所以y方向垂直于水平面，x方向平行于水平面，也就是说，x方向和z方向所确定的平面为平行于水平面。
此外，本实施例中，所述分光装置220的调节轴225平行于所述光轴，因此所述z轴与所述调节轴225平行。所述分光装置220绕所述调节轴225的旋转即为在x-y平面内，以z方向为旋转轴的旋转。所述分光装置220的第一方向与y方向之间夹角的变化即为所述分光装置220绕所述调节轴225旋转的角度。
将第一激光光束简化为平面波，则出射的第二激光光束(仅考虑与传播方向有关相位项)可以表示为：
E＝exp(j(k xx+k yy+k zz))
其中，当所述第一方向与y方向平行、即所述第一方向与y方向夹角为0时：
Figure PCTCN2018081367-appb-000011
Figure PCTCN2018081367-appb-000012
Figure PCTCN2018081367-appb-000013
式中，d 1为所述第一光栅周期；d 2为第二光栅周期，n x和n y分别代表在x方向和y方向上的衍射级次。
则根据光栅原理公式，第二激光光束传播方向与光栅平面法线之间的夹角θ为：
Figure PCTCN2018081367-appb-000014
由上式可以看出，对于y方向上的衍射级次n y不同时，相邻第二激光光束之间的夹角不相同，然而由于第一光栅周期d 1远大于第一激光光束的波长，因此，y方向上的衍射级次n y不同的相邻第二激光光束之间的夹角近似相等。所述多个第二激光光束在目标平面上所形成光斑呈矩阵式排列，图6示出了在所述第一方向与y正方向夹角为0时，图5所示激光雷达实施例在目标平面上所形成光斑的示意图。
当所述第一方向与y方向不平行、所述第一方向与y方向锐角夹角为
Figure PCTCN2018081367-appb-000015
时，所形成第二激光光束(仅考虑与传播方向有关相位项)可以表示为：
E＝exp(j(k xx+k yy+k zz))
其中，
Figure PCTCN2018081367-appb-000016
Figure PCTCN2018081367-appb-000017
Figure PCTCN2018081367-appb-000018
则根据光栅原理公式，第二激光光束传播方向与光栅平面法线之间的夹角θ为：
Figure PCTCN2018081367-appb-000019
多条第二激光光束在目标平面上所形成光斑依旧呈矩阵式排列，但是随着所述分光装置220的转动，光斑所形成的矩阵也随之转动，图7示出了在所述第一方向与y方向锐角夹角为
Figure PCTCN2018081367-appb-000020
时，图5所示激光雷达实施例在目标平面上所形成光斑的示意图。
如图6和图7所示，沿x方向排列的光斑随着所述分光装置220的转动而错开；目标平面上的每一个光斑与一个所述第二激光光束相对应，y方向相邻光斑之间的距离越大，所对应第二激光光束与水平面之间夹角越大；与水平面之间夹角具有差异的第二激光光束的数量越多，所述激光雷达的垂直角分辨率越高。
因此随着所述分光装置220的转动，更多的第二激光光束与水平面之间的夹角出现差异，也就是说，所述分光装置220的转动能够有效提高所述激光雷达的垂直角分辨率。所以所述将所述分光装置220设置为可旋转的做法，能够实现不同环境需求下，所述激光雷达的角分辨率，有利于提高所述激光雷达的探测精度和准确度。
本实施例中，所述分光装置220为m×n分束的二维达曼光栅，m为沿所述第一方向所形成第二激光光束个数，n为沿所述第二方向的所形成第二激光光束个数。
根据光栅原理方程，近似可以得到，所述第一方向与y方向之间 的锐角夹角
Figure PCTCN2018081367-appb-000021
为
Figure PCTCN2018081367-appb-000022
还需要说明的是，本实施例中，以所述第一方向与y方向平行、即所述第一方向与y方向夹角
Figure PCTCN2018081367-appb-000023
为0时，所述分光装置220的位置为初始位置。由于所述分光装置220的第一方向与y方向之间夹角的变化即为所述分光装置220绕所述调节轴225旋转的角度。因此所述第一方向与y方向锐角夹角
Figure PCTCN2018081367-appb-000024
的角度即为所述分光装置220绕所述调节轴225旋转的角度。
本实施例中，所述分光装置220绕所述调节轴225旋转的角度在
Figure PCTCN2018081367-appb-000025
到
Figure PCTCN2018081367-appb-000026
范围内，即所述第一方向与y方向锐角夹角
Figure PCTCN2018081367-appb-000027
在
Figure PCTCN2018081367-appb-000028
到
Figure PCTCN2018081367-appb-000029
范围内。合理设置所述分光装置220旋转角度范围，不仅能够增大激光雷达的角分辨率，还能够沿y方向相邻光斑之间的距离接近，从而使相邻第二激光光束之间的夹角相一致，从而提高第二激光光束在垂直方向上的分布均匀性，有利于激光雷达性能的改善。
具体的，本实施例中，所述分光装置220为32×32分束，所述第一光栅周期d 1和第二光栅周期d 2为52μm，所述第一激光光束波长 为905nm。沿y方向，所述激光雷达的视场角约为30°，所述第二激光光束与水平面之间夹角在-20°到+10°范围内，相邻所述第二激光光束之间的夹角近似相等，所以旋转之前，所述激光雷达的垂直角分辨率约为0.9375°(30°/32)；旋转之后，所述激光雷达的垂直角分辨率约为0.0293°(30°/(32×32))。由此可见：在沿平行于所述旋转轴的方向上，所述激光雷达具有很高的角分辨率。本发明其他实施例中，所述分光装置还可以是5×5分束、8×8分束、16×16分束或5×8分束的达曼光栅。
需要说明的是，本实施例中，所述分光装置设置为二维达曼光栅。但是这种做法仅为一实例。本发明其他实施例中，所述分光装置也可以设置为一维光栅，以降低光栅制造成本和制作工艺难度，从而达到控制成本的目的。具体的，所述分光装置也可以设置为一维达曼光栅。
当所述分光装置设置为一维光栅时，所述分光装置具有沿第一方向的第一光栅周期d 1，所形成第二激光光束传播方向与y方向之间的夹角为：
Figure PCTCN2018081367-appb-000030
其中，λ是第一激光光束的波长，
Figure PCTCN2018081367-appb-000031
是所述分光装置的第一方向与y方向锐角夹角。n y是y方向上的衍射级次。
如图8所示，示出了本发明激光雷达第三实施例在目标平面上所形成光斑的示意图。其中，光斑341为所述分光装置的第一方向与y方向锐角夹角为0时所形成的光斑；光斑342所述分光装置的第一方向与y方向锐角夹角为
Figure PCTCN2018081367-appb-000032
时所形成的光斑。
随着所述分光装置的旋转，沿y方向上，相邻光斑之间的距离减小，相邻第二激光光束之间的夹角减小，所述激光雷达的垂直辨率随之增大。
但是如图8所示，所述分光装置的第一方向与y方向锐角夹角为 0时，沿y方向，多个光斑341之间最远距离为r 1；，所述分光装置的第一方向与y方向锐角夹角为
Figure PCTCN2018081367-appb-000033
时，沿y方向，多个光斑342间最远距离为r 2；显然，r 1大于r 2。沿y方向，所述光斑之间最远距离与所述激光雷达的垂直视场角相关：沿y方向，光斑之间最远距离越大，垂直视场角越大。所以本实施例中，随着所述分光装置的旋转，所述激光雷达的垂直视场角会减小。
本实施例中，所述分光装置为一维光栅，所述分光装置具有沿第一方向的第一光栅周期；所述第一光栅周期为d，所述第一激光光束的波长为λ，所述分光装置为m×1分束的光栅，m为沿所述第一方向的激光光束的分束个数；所述分光装置绕所述调节轴旋转的角度小于
Figure PCTCN2018081367-appb-000034
其中，α为预设视场角。合理设置所述分光装置的旋转角度，能够使视场角大于预设视场角α，从而在保证激光雷达具有较高角分辨率的情况下，使激光雷达具有较大的视场角。具体的，本实施例中，所述预设视场角α大于或等于5°。
还需要说明的是，所述第二实施例与所述第三实施例中，所述分光装置能够绕所述调节轴旋转，即所述分光装置的第一方向与y方向的角度为可调，以适应不同的使用环境。但是本发明其他实施例中，所述分光装置的位置也可以固定，即所述分光装置的第一方向与y方向的角度为固定值，以提高所述激光雷达光路***的稳定性和精确性，从而达到改善激光雷达性能的目的。
当所述分光装置的位置固定时，可以通过使所述分光装置的第一方向与y方向呈一定角度，从而减小相邻第二激光光束在y方向上的夹角，在有限的第二激光光束数量前提下，达到提高y方向上角分辨 率的目的。
具体的，本发明其他实施例中，所述发射装置具有与所述第一激光光束传播方向相交的扫描旋转轴，所述发射装置适宜于绕所述扫描旋转轴旋转；所述分光装置具有至少一个与光轴垂直的分光方向，所述分光方向与所述光轴所在平面为分光平面；所述多个第二激光光束在至少一个所述分光平面上的投影相互错开；所述分光方向与所述扫描旋转轴的夹角为大于或等于0°，且小于90°。所述分光装置为光栅，所述分光装置具有沿第一方向的第一光栅周期；所述分光方向为所述第一方向。所以所述分光装置设置为光栅时，所述分光装置可以设置为第一方向与所述扫描旋转轴之间夹角大于或等于0°，且小于90°，以使所述第二激光光束尽量沿扫描旋转轴的方向错开，从而在有限的第二激光光束数量的前提下，达到提高沿扫描旋转轴方向角分辨率的目的。
参考图9至图11，示出了本发明激光雷达第四实施例的光路示意图。其中，图10是图9所示激光雷达实施例中区域41中第一激光光束和第二激光光束的放大光路示意图；图11是图9所示激光雷达实施例中回波光束的放大光路示意图。
如图9至图11所示，本实施例与前述实施例相同之处，本发明在此不再赘述。本实施例与前述实施例不同之处在于，本实施例中，所述激光雷达还包括：振镜450，所述振镜450包括第一反射面450a，所述第一反射面450a适宜于反射所述第二激光光束；所述振镜450具有振动旋转轴(图中未示出)，所述振镜450适宜于绕所述振动旋转轴旋转，所述振动旋转轴与所述第一反射面450a的法线之间的夹角大于零。
通过所述振镜450绕所述振动旋转轴的旋转，能够改变经所述第一反射面450a反射的第二激光光束的传播方向，从而能够增大所述第二激光光束的扫描范围、增大所述激光雷达的视场角；而且所述振镜450的旋转只要使旋转前第二激光光束之间最小夹角范围内均被 扫描，所获取的视场角便能够达到第二激光光束之间的最大夹角范围，因此，所述振镜450与分光装置420的组合能够通过较小的振镜450转角获取较大的视场角，所以在相同的视场角要求下，能够有效减小振镜450的旋转角度，减小振镜450的旋转周期，从而有利于提高激光雷达的扫描帧频。
本实施例中，所述分光装置420为一维光栅。具体的，所述分光装置420为一维达曼光栅。经所述分光装置420分束，所形成的多个第二激光光束位于同一平面内。
投射至所述第一反射面450a的多个第二激光光束所在平面为传播平面(图中未示出)，所述第一反射面450a与传播平面具有交线，所述振动旋转轴与所述交线之间的夹角大于0°。本实施例中，所述振动旋转轴与所述交线之间的夹角为90°。
此外，所述发射装置410具有与所述第一激光光束传播方向相交的扫描旋转轴(图中未示出)，所述发射装置410适宜于绕所述扫描旋转轴旋转；所述振动旋转轴与所述扫描旋转轴之间的夹角大于0°。本实施例中，所述振动旋转轴与所述扫描旋转轴之间的夹角为90°。
本实施例中，所述振动旋转轴平行于所述第一反射面450a。所述振动旋转轴平行于所述第一反射面450a，有利于所述振镜450的安装。在其他实施例中，所述振动旋转轴可以与所述第一反射面之间具有锐角夹角。
具体的，本实施例中，所述振镜260为激光扫描振镜或微机电扫描振镜。
需要说明的是，如图9和图10所示，本实施例中，所述激光雷达还包括：准直透镜451，所述准直透镜451适宜于对多个第二激光光束进行准直处理，使多个第二激光光束的传播方向平行；以及聚焦透镜452，所述聚焦透镜452适宜于将经过准直处理的第二激光光束会聚至所述振镜450的第一反射面450a。
所述分光装置420与所述准直透镜451的焦点之间的距离小于所述准直透镜451的焦深的一半，具体的，所述分光装置420位于所述准直透镜451的焦平面处。
所述振镜450与所述聚焦透镜452之间的距离小于聚焦透镜452焦深的一半。具体的，本实施例中，所述振镜450位于所述聚焦透镜452的焦平面处。
所述聚焦透镜452的焦点与所述准直透镜451的焦点重合，且所述聚焦透镜452的光轴与准直透镜451的光轴重合。所述准直透镜451和聚焦透镜452的设置能够增加第二激光光束汇聚到振镜450第一反射面的第二激光光束的数量，从而能够使增加振镜450反射出的第二激光光束数量，从而能够增加激光雷达的视场角。
本实施例中，所述第一光束为线偏振光。由于线偏振光的偏振具有方向性，激光雷达的退偏度很小，因此，能够根据第一光束的偏振方向，滤除偏振方向不同的杂散光，从而能够提高激光雷达的信噪比。
此外，如图9和图11所示，所述激光雷达还包括：半透半反镜453，所述半透半反镜453适宜于使至少部分所述第二激光光束透过，并入射至所述振镜450的第一反射面450a；所述半透半反镜453包括第二反射面453a，所述第二反射面453a适宜于将经过振镜450反射回的回波光束反射至所述接收装置430中。
所述半透半反镜453能够使回波光束与第二激光光束分离，从而能够从而防止第二激光光束对接收装置430的干扰，降低第二激光光束对检测结果的影响，提高所述激光雷达的精度；还能够利用所述半透半反镜实现光路重叠，从而缩短所述激光雷达的光路，能够有效减小光学***体积，有利于减小所述激光雷达的体积。如图9所示，所述半透半反镜453的第二反射面453a朝向所述振镜450的第一反射面450a。
另外，本实施例中，所述激光雷达还包括：接收会聚透镜454， 用于将经所述半透半反镜453出射的回波光束会聚至所述接收装置430中；所述接收装置430与接收会聚透镜454焦点之间的距离小于第二聚焦454透镜焦深的一半。
所述接收会聚透镜454与所述探测器之间的距离小于所述接收会聚透镜454焦深的一半。具体，本实施例中，所述探测器位于所述接收会聚透镜454的焦平面处。
所述激光雷达能够通过较小的振镜260旋转角获取较大的视场角。以下对本实施例中激光雷达的性能进行分析。
本实施例中，以所述分数装置420设置为1×9分束的一维达曼光栅。但是本发明其他事实中，所述分束装置也可以设置为其他参数、其他种类的光学元件，并不能以此限制本发明。
本实施例中，经所述聚焦透镜452会聚，所述多个第二激光光束聚焦于所述第一反射面450a的中心位置。所述待探测目标409表面任意一点所在的平面为目标平面，所述目标平面与所述第一反射面450a中心位置之间的距离为l。需要说明的是，本实施例中，所述目标平面垂直于水平面。
结合参考图12至图14，示出了图9所示激光雷达实施例在振镜振动不同时刻所述多个第二激光光束在所述目标平面上所形成光斑的示意图。
在所述目标平面上建立直角坐标系，所建立直角坐标系包括：两两互相垂直的x方向、y方向和z方向，其中y方向与所述分光装置420光栅周期方向平行，即y方向平行于所述分光装置420的分光方向。
如图12所示，本实施例中，经所述分光装置420分光所形成的多个第二激光光束，经所述第一反射面450a反射后，投射至所述目标平面上形成多个光斑441，所述多个光斑441在所述目标平面上形成1×9的光斑阵列，所述光斑阵列具有沿y方向的阵列周期dy，即 沿y方向相邻光斑441之间的间距为dy。
需要说明的是，本实施例中，为简化计算，假设所述振动旋转轴平行于水平面，且当所述第一反射面450a绕所述振动旋转轴沿顺时针方向转动时，所述振镜450的旋转角度为正值，当所述第一反射面450a绕所述振动旋转轴沿逆时针方向转动时，所述振镜450的旋转角度为负值。
对于一个第二激光光束而言，在入射角度不发生变化的前提下，所述振镜450旋转θ弧度时，所述第一反射面450a的法向转动角度也为+θ弧度，根据光学反射原理，经所述第一反射面450a反射的第二激光光束转过角度为2θ弧度。
如图13所述，所述振镜450旋转θ＝dy/4l弧度时，经所述第一反射面450a反射的第二激光光束转过角度为2θ＝dy/2l弧度，旋转后的第二激光光束在所述目标平面上形成光斑442。光斑442位于光斑441沿y正方向的一侧，光斑442与光斑441之间间隔约为dy/2。
如图14所述，所述振镜450旋转θ＝-dy/4l弧度时，经所述第一反射面450a反射的第二激光光束转过角度为2θ＝-dy/2l弧度，旋转后的第二激光光束在所述目标平面上形成光斑443。光斑443位于光斑441沿y负方向的一侧，光斑443与光斑441之间间隔约为dy/2。
由图13和图14可以知道，当所述振镜450旋转角度在-dy/4l弧度到dy/4l弧度之间时，相连第二激光光束之间区域均能够被所述第二激光光束扫描到。所以所述激光雷达的视场角即为所述振镜450旋转的最大角度与经所述振镜450反射的多个第二激光光束之间最大夹角的叠加。
本实施例中，所述分数装置420设置为1×9分束的一维达曼光栅；在y方向上，所述激光雷达的视场角为9dy/l弧度。具体的，假设dy/l＝10°，则所述振镜450旋转的最大角度为5°，所述激光雷达沿y方向的视场角为90°。因此，所述振镜与分光装置的组合能 够通过较小的振镜转角获取较大的视场角，而且在相同的视场角要求下，能够有效减小振镜的旋转角度，减小振镜的旋转周期，从而有利于提高激光雷达的扫描帧频。
本实施例中，当所述振动旋转轴平行于所述传播平面且平行于所述第一反射面450a时，所述振镜450绕所述振动旋转轴旋转能够增加激光雷达沿垂直于扫描旋转轴方向的视场角。当所述振动旋转轴与所述传播平面具有锐角夹角时，所述振镜450绕所述振动旋转轴旋转能够增加激光雷达沿垂直于扫描旋转轴方向以及平行于所述扫描旋转轴方向的视场角。
本发明其他实施例中，所述分光装置还可以为二维达曼光栅，当所述振动旋转轴不垂直于所述第一反射面时，所述振镜绕所述振动旋转轴旋转，能够通过较小的振镜转角，使激光雷达具有较大的沿垂直于扫描旋转轴方向以及平行于所述扫描旋转轴方向的视场角，能够有效扩大所述多个第二激光光束的传播范围，有利于增加激光雷达沿各方向的角分辨率和视场角。
参考图15，示出了本发明激光雷达第五实施例的结构示意图。
本实施例与前述实施例相同之处本发明在此不再赘述。本实施例与前述实施例不同之处在于，本实施例中，所述发射装置510适宜于同时产生多个传播方向不同的第一激光光束。
所述分光装置520能够使每一个第一激光光束510a经分为多个第二激光光束520b，因此多个传播不同的第一激光光束510a的产生能够增加所形成第二激光光束520b的数量，且由传播方向不同的第一激光光束510a产生的第二激光光束520b传播方向均不相同，从而能够进一步增加激光雷达的角分辨率。
具体的，如图15所示，本实施例中，所述发射装置510包括：多个激光器511，所述多个激光器511的出光方向相互平行；会聚透镜512，所述会聚透镜512适宜于使多个激光器511产生的第一激光 光束会聚至所述分光装置520。
所述会聚透镜512能够使出光方向相同的多个激光器511产生会聚至所述分光装置520的第一激光光束510a，既能够降低所述多个激光器511的安装难度，又能够产生多个传播方向不同的第一激光光束510a，从而能够有效降低所述多个激光器511的安装难度，有利于降低安装成本，还能够有效提高所述第一激光光束510a光路的准确性，有利于提高所述激光雷达的探测准确性和探测精度。
本实施例中，所述激光雷达还具有多个扩束准直装置(图中未标示)，所述多个扩束准直装置与所述多个激光器511一一对应，所述扩束准直装置分别用于对所对应激光器所产生的第一激光光束进行扩散和准直。
具体的，本实施例中，所述会聚透镜512的光轴与所述分光装置520的光轴重合；所述多个激光器512的出光方向平行于所述会聚透镜512的光轴。
因此所述多个激光器512所产生的多个第一激光光束510a相互平行，平行于所述会聚透镜512的光轴，经所述会聚透镜512透射，所述多个第一激光光束510a会聚于所述分光装置520上，且不同第一激光光束510a与所述分光装置520光轴的夹角均不相同，因此每一个第一激光光束510a所产生的多个第二激光光束520a与所述分光装置520光轴的夹角也不相同，从而能够达到增大所述激光雷达角分辨率和视场角的目的。
具体的，本实施例中，所述多个激光器510沿垂直水平面的方向排列，所述分光装置520的分光方向垂直水平面，因此所述多个第一激光光束510a的产生，能够有效扩大所述激光雷达的垂直视场角、提高所述激光雷达的垂直角分辨率。
需要说明的是，本实施例中，所述分光装置520到所述会聚透镜512焦平面的距离小于所述会聚透镜512焦深的一半。具体的，所述 分光装置520位于所述会聚透镜512的焦平面处。
此外，本实施例中，所述分光装置520为二维光栅。具体的，所述分光装置520为二维达曼光栅。而且，所述分光装置520适宜于绕平行光轴的调节轴旋转。如图16所示，示出了本实施例中，所述分光装置520绕所述调节轴旋转前后在所述目标平面上所形成光斑的分布示意图。由此可见，所述多个第一激光光束的形成与旋转所述分光装置520的组合，能够有效提高所述激光雷达的角分辨率、能够有效拓展所述激光雷达的视场角。
还需要说明的是，本实施例中，所述发射装置通过所述会聚透镜512形成多个传播方向不同的第一激光光束。如图17所示，本发明其他实施例中，所述发射装置也可以包括多个激光器611，所述多个激光器611的出光方向至少两两相交，也就是说，所述多个激光器611的出光方向不平行或者不相同。这种方式能够有效减少光学元件的数量，简化所述激光雷达的光路。
此外，需要说明的是，上述实施例中，所述分光装置设置为达曼光栅的做法仅为一实例，本发明其他实施例中，所述分光装置还可以为包括光纤分束器、平面衍射光栅或者闪耀光栅等在内的其他光学元件，或者是经设计满足功能需求的光子晶体元件。此外，所述分光装置也可以是由多个光学元件(例如透镜、分光镜等)组成的光学***。所述分光装置可以设置为能够通过光线折射、反射、衍射或者干涉作用，将一个第一激光光束分为多个传播方向不同的第二激光光束的任意光学***或者光学元器件。
其中，由于平面衍射光栅、闪耀光栅通常为一维光栅，因此在一些实施例中，将所述分光装置设置为平面衍射光栅、闪耀光栅时，所述激光雷达还包括有扫描器件，以保证所述激光雷达水平方向和垂直方向的视场角和角分辨率。
相应的，本发明还提供一种激光雷达的工作方法。
所述激光雷达的工作方法包括：首先执行步骤S100，提供激光 雷达，参考图2至图4，所述激光雷达包括：发射装置110(如图3所示)，所述发射装置110适宜于产生第一激光光束110a(如图3所示)；分光装置120(如图3所示)，所述分光装置120适宜于将第一激光光束110a分为沿不同方向传播的多个第二激光光束120b(如图3所示)；所述第二激光光束(如图3所示)经待探测目标(图中未示出)反射形成回波光束130c(如图4所示)；接收装置130(如图3所示)，所述接收装置130适宜于接收所述回波光束130c。
所述激光雷达的具体技术方案，参考前述激光雷达的具体实施例，本发明在此不再赘述。
具体的，本实施例中，所述分光装置为达曼光栅，以避免因所述多个第二激光光束中某束光强度过小而难以被检测，能够有效保证所述多个第二激光光束的探测距离，保证所述接收装置对所述回波光束的成功探测，有利于提高所述激光雷达对待探测目标的探测精度和准确性。
接着，执行步骤S200，使所述发射装置110产生第一激光光束110a；所述第一激光光束110a经过所述分光装置120，分为多个传播方向不相同的第二激光光束120b；至少部分所述第二激光光束120b到达所述待探测目标后反射形成回波光束130c。
本实施例中，使所述发射装置110产生第一激光光束110a的步骤即为开启所述发射装置110中的激光器，使所述激光器产生第一激光光束110a。
之后，执行步骤S300，通过所述接收装置130接收所述回波光束130c。
如图4所示，所述接收装置包括多个探测器130，各探测器130分别适宜于接收相应的第二激光光束(图中未示出)经待探测目标反射的回波光束130c。
本实施例中，执行步骤S300，通过所述接收装置接收所述回波光束130c的过程包括：所述多个探测器131同时接收所述回波光束130c，以减小损耗，提高扫描频率。
本发明其他实施例中，执行步骤S300，通过所述接收装置接收所述回波光束的过程也可以包括：所述多个探测器依次接收所对应的回波光束。具体的，所述多个探测器可以依照一定时序接收所对应的回波光束，从而防止不同回波光束之间的干扰，以保证所述激光雷达的探测精度和准确性。
通过所述分光装置120将第一激光光束110a分为多束第二激光光束120b能够通过一个激光器获得多束第二激光光束120b，从而能够大量节约激光器的数量，进而能够降低所述激光雷达的成本及安装难度。所述激光雷达具有较高的视场角和角分辨率，且成本低。
参考图5，示出了本发明激光雷达工作方法第二实施例中所提供激光雷达的结构示意图。
本实施例与第一实施例相同之处，本发明在此不再赘述。本实施例与前述实施例不同之处在于，本实施例中，所述分光装置220具有与光轴平行的调节轴225；所述分光装置220适宜于绕所述调节轴225旋转。
所以执行步骤200，使所述发射装置产生第一激光光束，所述第一激光光束经所述分光装置220分为所述多个第二激光光束之后，执行步骤S210，根据预设垂直分辨率，旋转所述分光装置220。
根据前述分析，所述分光装置220的旋转，能够有效调节所述激光雷达的角分辨率和视场角，因此根据不同环境需求，设置预设分辨率，能够实现所述激光雷达的高角分辨率和大视场角的兼顾，有利于提高所述激光雷达的探测精度和准确度，有利于改善所述激光雷达在不同环境下的应用表现。
需要说明的是，本实施例中，所述分光装置220为二维光栅，所述分光装置220具有沿第一方向的第一光栅周期和沿第二方向的第二光栅周期，所述第一方向与第二方向垂直；所述第一光栅周期为d 1，所述第二光栅周期为d 2，所述第一激光光束的波长为λ，所述分 光装置220为m×n分束的光栅，m为沿所述第一方向所形成第二激光光束个数，n为沿所述第二方向所形成第二激光光束个数；绕所述调节轴225旋转所述分光装置220的过程中，所述分光装置220旋转的角度的范围为：
Figure PCTCN2018081367-appb-000035
到
Figure PCTCN2018081367-appb-000036
合理调节所述分光装置220旋转角度范围，不仅能够增大激光雷达的角分辨率，还能够使相邻第二激光光束之间的夹角相一致，从而提高第二激光光束在垂直方向上的分布均匀性，有利于激光雷达性能的改善。
还需要说明的是，本发明其他实施例中，所述分光装置也可以设置为一维光栅。所述分光装置为一维光栅时，所述分光装置具有沿第一方向的第一光栅周期；所述第一光栅周期为d，所述第一激光光束的波长为λ，所述分光装置为m×1分束的光栅，m为沿所述第一方向的激光光束的分束个数；绕所述调节轴旋转所述分光装置的过程中，所述分光装置旋转的角度小于
Figure PCTCN2018081367-appb-000037
其中，α为预设视场角。绕所述调节轴旋转所述分光装置的过程合理控制所述分光装置旋转的角度，能够使视场角大于预设视场角α，从而在保证激光雷达具有较高角分辨率的情况下，使激光雷达具有较大的视场角。具体的，一些实施例中，所述预设视场角α大于或等于5°。
参考图9至图11，示出了本发明激光雷达工作方法第三实施例中所提供激光雷达的结构示意图。
本实施例与前述实施例相同之处，本发明在此不再赘述。本实施例与前述实施例不同之处在于，本实施例中，所述激光雷达还包括：振镜，所述振镜包括第一反射面，所述第一反射面适宜于反射所述第二激光光束；所述振镜具有振动旋转轴，所述振镜适宜于绕所述振动旋转轴旋转，所述振动旋转轴与所述第一反射面的法线之间的夹角大于零。
因此本实施例中，执行步骤200，使所述发射装置产生第一激光光束，所述第一激光光束经所述分光装置分为所述多个第二激光光束之后，执行步骤220，旋转所述振镜，改变自振镜反射出的第二激光光束的传播方向。
所述振镜450与分光装置420的组合能够通过较小的振镜450转角获取较大的视场角，所以在相同的视场角要求下，能够有效减小振镜450的旋转角度，减小振镜450的旋转周期，从而有利于提高激光雷达的扫描帧频。
需要说明的是，本实施例中，所述分光装置420为光栅，所述分光装置420具有沿第一方向的第一光栅周期，所述振镜反射出的第二激光光束在沿第一方向之间的最小夹角为θ 1，所述扫描旋转轴垂于所述第一方向。因此旋转所述振镜的过程中，使振镜旋转角度大于或等于θ 1/2。所述振镜450较小的旋转角度，能够有效缩短所述振镜450的振动周期，从而有利于提高所述激光雷达的扫描帧频。
参考图15，示出了本发明激光雷达工作方法第四实施例中所提供激光雷达的结构示意图。
本实施例与前述实施例相同之处，本发明在此不再赘述。本实施例与前述实施例不同之处在于，本实施例中，所述发射装置适宜于同时产生多个传播方向不同的第一激光光束；所述发射装置包括多个激光器。
所以执行步骤S200，使所述发射装置510产生第一激光光束510a的步骤包括，根据预设分辨率，开启至少一个激光器以产生至少一个第一激光光束。
根据前述分析可知，所述分光装置520能够使每一个第一激光光束510a分为多个第二激光光束520b，而不同传播方向第一激光光束510，经所述分光装置520分束后所形成的多个第二激光光束520b传播方向不尽相同。
另一方面，激光器开启数量越多，所述激光雷达的能耗越高，所述激光雷达光学***的符合越高，因此根据预设分辨率，合理设置开启激光器的数量以及合理选择所开启的激光器，能有在保证使用分辨率要求的前提下，提高所述第二激光光束的利用率，有效控制所述激光雷达的能耗，有效降低所述激光雷达光学***的符合，有利于节省能源、延长使用时间，有利于降低损耗、延长使用寿命，有利于实现角分辨率和能耗控制的兼顾。

Claims (31)

  1. 一种激光雷达，其特征在于，包括：
    发射装置，所述发射装置适宜于产生第一激光光束；
    分光装置，所述分光装置适宜于将第一激光光束分为沿不同方向传播的多个第二激光光束；
    至少部分所述第二激光光束经待探测目标反射形成回波光束；
    接收装置，所述接收装置适宜于接收所述回波光束。
  2. 如权利要求1所述的激光雷达，其特征在于，所述分光装置具有光轴，垂直所述光轴的平面为目标平面；
    所述分光装置还适宜于使所述多个第二激光光束在所述目标平面内所成光斑疏密分布。
  3. 如权利要求2所述的激光雷达，其特征在于，在所述目标平面内，所述第二激光光束所形成光斑沿远离所述光轴的方向分布密度逐渐减小。
  4. 如权利要求1所述的激光雷达，其特征在于，所述分光装置具有与光轴平行的调节轴；所述分光装置适宜于绕所述调节轴旋转以改变所述多个第二激光光束的传播方向。
  5. 如权利要求1至4任意一项所述的激光雷达，其特征在于，所述分光装置为光栅或光纤分束器。
  6. 如权利要求5所述的激光雷达，其特征在于，所述分光装置为达曼光栅。
  7. 如权利要求4所述的激光雷达，其特征在于，所述分光装置为一维光栅，所述分光装置具有沿第一方向的第一光栅周期；
    所述第一光栅周期为d，所述第一激光光束的波长为λ，所述分光装置为m×1分束的光栅，m为沿所述第一方向的激光光束的分束 个数；
    所述分光装置绕所述调节轴旋转的角度小于
    Figure PCTCN2018081367-appb-100001
    其中，α为预设视场角。
  8. 如权利要求7所述的激光雷达，其特征在于，所述分光装置的第一光栅周期在47μm到57μm范围内；所述第一激光光束的波长在895nm到915nm范围内。
  9. 如权利要求4所述的激光雷达，其特征在于，所述分光装置为二维光栅，所述分光装置具有沿第一方向的第一光栅周期和沿第二方向的第二光栅周期，所述第一方向与第二方向垂直；
    所述第一光栅周期为d 1，所述第二光栅周期为d 2，所述第一激光光束的波长为λ，所述分光装置为m×n分束的光栅，m为沿所述第一方向所形成第二激光光束个数，n为沿所述第二方向所形成第二激光光束个数；
    所述分光装置绕所述调节轴旋转的角度在
    Figure PCTCN2018081367-appb-100002
    到
    Figure PCTCN2018081367-appb-100003
    范围内。
  10. 如权利要求9所述的激光雷达，其特征在于，所述分光装置的第一光栅周期在47μm到57μm范围内；所述第一激光光束的波长在895nm到915nm范围内；所述第二光栅周期在47μm到57μm范围内。
  11. 如权利要求1所述的激光雷达，其特征在于，所述发射装置具有与所述第一激光光束传播方向相交的扫描旋转轴，所述发射装 置适宜于绕所述扫描旋转轴旋转；
    所述分光装置的光轴与所述扫描旋转轴的夹角大于0°，且小于或等于90°。
  12. 如权利要求11所述的激光雷达，其特征在于，所述分光装置具有至少一个与光轴垂直的分光方向，所述分光方向与所述光轴所在平面为分光平面；
    所述多个第二激光光束在至少一个所述分光平面上的投影相互错开；
    所述分光方向与所述扫描旋转轴的夹角为大于或等于0°，且小于90°。
  13. 如权利要求12所述的激光雷达，其特征在于，所述分光装置为光栅，所述分光装置具有沿第一方向的第一光栅周期；
    所述分光方向为所述第一方向。
  14. 如权利要求1所述的激光雷达，其特征在于，还包括：振镜，所述振镜包括第一反射面，所述第一反射面适宜于反射所述第二激光光束；
    所述振镜具有振动旋转轴，所述振镜适宜于绕所述振动旋转轴旋转，所述振动旋转轴与所述第一反射面的法线之间的夹角大于零。
  15. 如权利要求14所述的激光雷达，其特征在于，所述分光装置为一维光栅，所述多个第二激光光束位于同一平面内；
    投射至所述第一反射面的多个第二激光光束所在平面为传播平面，所述第一反射面与传播平面具有交线，所述振动旋转轴与所述交线之间的夹角大于0°。
  16. 如权利要求14所述的激光雷达，其特征在于，所述发射装置具有与所述第一激光光束传播方向相交的扫描旋转轴，所述发射 装置适宜于绕所述扫描旋转轴旋转；
    所述振动旋转轴与所述扫描旋转轴之间的夹角大于0°。
  17. 如权利要求14所述的激光雷达，其特征在于，还包括：准直透镜，所述准直透镜适宜于对多个第二激光光束进行准直处理，使多个第二激光光束的传播方向平行；
    聚焦透镜，所述聚焦透镜适宜于将经过准直处理的第二激光光束会聚至所述振镜的第一反射面。
  18. 如权利要求14所述的激光雷达，其特征在于，还包括：半透半反镜，所述半透半反镜适宜于使至少部分所述第二激光光束透过，并入射至所述振镜的第一反射面；
    所述半透半反镜包括第二反射面，所述第二反射面适宜于将经过振镜反射回的回波光束反射至所述接收装置中。
  19. 如权利要求18所述的激光雷达，其特征在于，还包括：接收会聚透镜，用于将经所述半透半反镜出射的回波光束会聚至所述接收装置中；所述接收装置与接收会聚透镜焦点之间的距离小于接收会聚透镜焦深的一半。
  20. 如权利要求1所述的激光雷达，其特征在于，所述发射装置适宜于同时产生多个传播方向不同的第一激光光束。
  21. 如权利要求20所述的激光雷达，其特征在于，所述发射装置包括多个激光器，所述多个激光器的出光方向至少两两相交。
  22. 如权利要求20所述的激光雷达，其特征在于，所述发射装置包括：多个激光器，所述多个激光器的出光方向相互平行；会聚透镜，所述会聚透镜适宜于使多个激光器产生的第一激光光束会聚至所述分光装置；
    所述分光装置到所述会聚透镜焦平面的距离小于会聚透镜焦深的一半。
  23. 一种激光雷达的工作方法，其特征在于，包括：
    提供激光雷达，所述激光雷达包括：发射装置，所述发射装置适宜于产生第一激光光束；分光装置，所述分光装置适宜于将第一激光光束分为沿不同方向传播的多个第二激光光束；所述第二激光光束经待探测目标反射形成回波光束；接收装置，所述接收装置适宜于接收所述回波光束；
    使所述发射装置产生第一激光光束；所述第一激光光束经过所述分光装置，分为多个传播方向不相同的第二激光光束；
    至少部分所述第二激光光束到达所述待探测目标后反射形成回波光束；
    通过所述接收装置接收所述回波光束。
  24. 如权利要求23所述的工作方法，其特征在于，所述分光装置具有与光轴平行的调节轴；所述分光装置适宜于绕所述调节轴旋转；
    使所述发射装置产生第一激光光束，所述第一激光光束经所述分光装置分为所述多个第二激光光束之后，根据预设分辨率，旋转所述分光装置。
  25. 如权利要求24所述的工作方法，其特征在于，所述分光装置为一维光栅，所述分光装置具有沿第一方向的第一光栅周期；
    所述第一光栅周期为d，所述第一激光光束的波长为λ，所述分光装置为m×1分束的光栅，m为沿所述第一方向的激光光束的分束个数；
    绕所述调节轴旋转所述分光装置的过程中，所述分光装置旋转的角度小于
    Figure PCTCN2018081367-appb-100004
    其中，α为预设视场角。
  26. 如权利要求24所述的工作方法，其特征在于，所述分光装置为二维光栅，所述分光装置具有沿第一方向的第一光栅周期和沿第二方向的第二光栅周期，所述第一方向与第二方向垂直；
    所述第一光栅周期为d 1，所述第二光栅周期为d 2，所述第一激光光束的波长为λ，所述分光装置为m×n分束的光栅，m为沿所述第一方向所形成第二激光光束个数，n为沿所述第二方向所形成第二激光光束个数；
    绕所述调节轴旋转所述分光装置的过程中，所述分光装置旋转的角度的范围为：
    Figure PCTCN2018081367-appb-100005
    到
    Figure PCTCN2018081367-appb-100006
  27. 如权利要求23所述的工作方法，其特征在于，所述激光雷达还包括：
    振镜，所述振镜包括第一反射面，所述第一反射面适宜于反射所述第二激光光束；所述振镜具有振动旋转轴，所述振镜适宜于绕所述振动旋转轴旋转，所述振动旋转轴与所述第一反射面的法线之间的夹角大于零；
    使所述发射装置产生第一激光光束，所述第一激光光束经所述分光装置分为所述多个第二激光光束之后，旋转所述振镜，改变自振镜反射出的第二激光光束的传播方向。
  28. 如权利要求27所述的工作方法，其特征在于，所述分光装置为光栅，所述分光装置具有沿第一方向的第一光栅周期，所述振镜反射出的第二激光光束在沿第一方向之间的最小夹角为θ 1，所述扫描旋转轴垂于所述第一方向；
    旋转所述振镜的过程中，使振镜旋转角度大于或等于θ 1/2。
  29. 如权利要求23所述的工作方法，其特征在于，所述发射装置适宜于同时产生多个传播方向不同的第一激光光束；所述发射装置包括多个激光器；
    使所述发射装置产生第一激光光束的步骤包括，根据预设分辨率，开启至少一个激光器以产生至少一个第一激光光束。
  30. 如权利要求23所述的工作方法，其特征在于，所述接收装置包括多个探测器，各探测器分别适宜于接收相应的第二激光光束经待探测目标反射的回波光束；
    通过所述接收装置接收所述回波光束的过程包括：所述多个探测器同时接收所述回波光束；
    或者，所述多个探测器依次接收所对应的回波光束。
  31. 如权利要求23所述的工作方法，其特征在于，所述分光装置为达曼光栅。
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110988844A (zh) * 2019-12-27 2020-04-10 陈泽雄 一种光路***及激光雷达
EP3518000B1 (de) * 2018-01-26 2021-01-06 Sick Ag Optoelektronischer sensor und verfahren zur erfassung von objekten
CN112596043A (zh) * 2020-12-07 2021-04-02 西安工业大学 一种高角分辨率激光雷达及探测方法
CN113267777A (zh) * 2020-02-17 2021-08-17 上海禾赛科技有限公司 一种激光雷达
CN113740876A (zh) * 2021-08-13 2021-12-03 探维科技(北京)有限公司 三维激光雷达光路调节方法、装置和电子设备
CN113869196A (zh) * 2021-09-27 2021-12-31 中远海运科技股份有限公司 一种基于激光点云数据多特征分析的车型分类方法及装置
WO2022209369A1 (ja) * 2021-03-31 2022-10-06 ソニーセミコンダクタソリューションズ株式会社 光学モジュールおよび測距装置
CN115629370A (zh) * 2022-12-23 2023-01-20 浙江华是科技股份有限公司 激光雷达探测***及方法
WO2023071156A1 (zh) * 2021-10-26 2023-05-04 上海禾赛科技有限公司 Fmcw激光雷达及其光路转换模块、探测方法
WO2023096703A1 (en) * 2021-11-24 2023-06-01 Wrap Technologies, Inc. Systems and methods for generating optical beam arrays
CN116299339A (zh) * 2023-05-25 2023-06-23 西安炬光科技股份有限公司 激光发射装置、激光接收装置及激光雷达

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4253998A1 (en) * 2022-03-30 2023-10-04 Robert Bosch GmbH Lidar unit with diffractive optical element

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7583364B1 (en) * 2004-03-19 2009-09-01 University Corporation For Atmospheric Research High pulse-energy, eye-safe lidar system
CN102749626A (zh) * 2012-07-17 2012-10-24 奇瑞汽车股份有限公司 雷达传感器、汽车以及目标方位识别方法
CN104297760A (zh) * 2014-10-09 2015-01-21 中国科学院合肥物质科学研究院 车载脉冲式激光雷达***
CN106684694A (zh) * 2017-02-17 2017-05-17 北京工业大学 一种用于多线激光雷达的激光分束装置
CN206321794U (zh) * 2016-12-30 2017-07-11 深圳市速腾聚创科技有限公司 多线激光雷达
CN107153194A (zh) * 2016-12-30 2017-09-12 深圳市速腾聚创科技有限公司 多线激光雷达及多线激光雷达控制方法

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0283222B1 (en) * 1987-03-20 1994-01-12 Digital Optronics Corporation 3-Dimensional vision system utilizing coherent optical detection
JP3411780B2 (ja) * 1997-04-07 2003-06-03 レーザーテック株式会社 レーザ顕微鏡及びこのレーザ顕微鏡を用いたパターン検査装置
US7049586B2 (en) * 2002-02-21 2006-05-23 Applied Material Israel, Ltd. Multi beam scanning with bright/dark field imaging
EP2041515A4 (en) * 2006-07-13 2009-11-11 Velodyne Acoustics Inc HIGH DEFINITION LIDAR SYSTEM
CN103760682B (zh) * 2008-01-21 2016-08-31 苹果公司 用于使零级减少的光学设计
US8531650B2 (en) * 2008-07-08 2013-09-10 Chiaro Technologies LLC Multiple channel locating
JP5257053B2 (ja) * 2008-12-24 2013-08-07 株式会社豊田中央研究所 光走査装置及びレーザレーダ装置
KR101357051B1 (ko) * 2012-05-22 2014-02-04 한국생산기술연구원 3차원 스캐닝 시스템 및 이를 이용한 3차원 영상획득방법
JP6108812B2 (ja) * 2012-12-17 2017-04-05 オリンパス株式会社 挿入装置
US9903950B2 (en) * 2014-08-27 2018-02-27 Leica Geosystems Ag Multi-camera laser scanner
US10036803B2 (en) * 2014-10-20 2018-07-31 Quanergy Systems, Inc. Three-dimensional lidar sensor based on two-dimensional scanning of one-dimensional optical emitter and method of using same
CN107407553B (zh) * 2014-10-24 2020-07-28 魔眼公司 距离传感器
US9625582B2 (en) * 2015-03-25 2017-04-18 Google Inc. Vehicle with multiple light detection and ranging devices (LIDARs)
KR102454209B1 (ko) * 2015-07-30 2022-10-14 엘지이노텍 주식회사 광파 탐지 및 거리 측정 장치
WO2017073982A1 (ko) * 2015-10-30 2017-05-04 한국생산기술연구원 3차원 스캐닝 시스템
EP3408684A4 (en) * 2016-01-31 2019-10-02 Velodyne LiDAR, Inc. LIDAR-BASED 3-D IMAGERY WITH FAR-FIELD FIELD LIGHTING OVERLAPPING
CN106353766B (zh) * 2016-09-08 2019-10-11 上海理鑫光学科技有限公司 基于衍射光学元件的激光雷达多点测距***

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7583364B1 (en) * 2004-03-19 2009-09-01 University Corporation For Atmospheric Research High pulse-energy, eye-safe lidar system
CN102749626A (zh) * 2012-07-17 2012-10-24 奇瑞汽车股份有限公司 雷达传感器、汽车以及目标方位识别方法
CN104297760A (zh) * 2014-10-09 2015-01-21 中国科学院合肥物质科学研究院 车载脉冲式激光雷达***
CN206321794U (zh) * 2016-12-30 2017-07-11 深圳市速腾聚创科技有限公司 多线激光雷达
CN107153194A (zh) * 2016-12-30 2017-09-12 深圳市速腾聚创科技有限公司 多线激光雷达及多线激光雷达控制方法
CN106684694A (zh) * 2017-02-17 2017-05-17 北京工业大学 一种用于多线激光雷达的激光分束装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3742199A4

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3518000B1 (de) * 2018-01-26 2021-01-06 Sick Ag Optoelektronischer sensor und verfahren zur erfassung von objekten
US11624824B2 (en) 2018-01-26 2023-04-11 Sick Ag Optoelectronic sensor and method for detecting objects
CN110988844A (zh) * 2019-12-27 2020-04-10 陈泽雄 一种光路***及激光雷达
CN113267777A (zh) * 2020-02-17 2021-08-17 上海禾赛科技有限公司 一种激光雷达
CN112596043A (zh) * 2020-12-07 2021-04-02 西安工业大学 一种高角分辨率激光雷达及探测方法
CN112596043B (zh) * 2020-12-07 2024-03-29 西安工业大学 一种高角分辨率激光雷达及探测方法
WO2022209369A1 (ja) * 2021-03-31 2022-10-06 ソニーセミコンダクタソリューションズ株式会社 光学モジュールおよび測距装置
CN113740876A (zh) * 2021-08-13 2021-12-03 探维科技(北京)有限公司 三维激光雷达光路调节方法、装置和电子设备
CN113740876B (zh) * 2021-08-13 2023-04-14 探维科技(北京)有限公司 三维激光雷达光路调节方法、装置和电子设备
CN113869196A (zh) * 2021-09-27 2021-12-31 中远海运科技股份有限公司 一种基于激光点云数据多特征分析的车型分类方法及装置
CN113869196B (zh) * 2021-09-27 2022-04-19 中远海运科技股份有限公司 一种基于激光点云数据多特征分析的车型分类方法及装置
WO2023071156A1 (zh) * 2021-10-26 2023-05-04 上海禾赛科技有限公司 Fmcw激光雷达及其光路转换模块、探测方法
WO2023096703A1 (en) * 2021-11-24 2023-06-01 Wrap Technologies, Inc. Systems and methods for generating optical beam arrays
US11852439B2 (en) 2021-11-24 2023-12-26 Wrap Technologies, Inc. Systems and methods for generating optical beam arrays
CN115629370A (zh) * 2022-12-23 2023-01-20 浙江华是科技股份有限公司 激光雷达探测***及方法
CN116299339A (zh) * 2023-05-25 2023-06-23 西安炬光科技股份有限公司 激光发射装置、激光接收装置及激光雷达

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