CN114740452A - Off-axis laser radar - Google Patents

Off-axis laser radar Download PDF

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Publication number
CN114740452A
CN114740452A CN202210275218.2A CN202210275218A CN114740452A CN 114740452 A CN114740452 A CN 114740452A CN 202210275218 A CN202210275218 A CN 202210275218A CN 114740452 A CN114740452 A CN 114740452A
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China
Prior art keywords
detector
lens group
condenser lens
lidar
laser emitter
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CN202210275218.2A
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Chinese (zh)
Inventor
任玉松
白玉茹
林建东
单建勇
李进强
任雨杭
秦屹
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Whst Co Ltd
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Whst Co Ltd
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Priority to CN202210275218.2A priority Critical patent/CN114740452A/en
Publication of CN114740452A publication Critical patent/CN114740452A/en
Pending legal-status Critical Current

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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
    • G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
    • 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
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Electromagnetism (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

The invention relates to an off-axis laser radar which comprises a transmitting unit, a receiving unit and a light-transmitting outer cover, wherein the transmitting unit comprises a laser transmitter. The receiving unit comprises a detector and a condenser lens group, the detector is located on one side of the laser emitter along the first direction, the condenser lens group is arranged on one side of the detector along the second direction, the focal position of the condenser lens group is located on one side, away from the laser emitter, of the main optical axis of the condenser lens group, and the detector is located on the focal position of the condenser lens group. The scanning unit is arranged on one side of the detector and the laser transmitter along the second direction, and the condenser lens group is positioned between the scanning unit and the detector. The condensing lens is eccentrically arranged, so that the distance between the laser emitter and the detector can be increased under the condition that the size of the scanning unit is not changed, the electromagnetic interference on the detector caused by instantaneous large current generated by the laser diode can be reduced, and the detection precision is increased.

Description

Off-axis laser radar
Technical Field
The invention relates to the technical field of laser radars, in particular to an off-axis laser radar.
Background
The laser radar comprises a laser transmitter, a detector and a scanning unit. The laser emitter emits light beam (i.e. emission beam) to the target, the detector compares the received light beam (i.e. detection beam) reflected from the target with the emission beam, and after proper processing, the related information of the target, such as distance, direction, height, speed, attitude, and even shape of the target, can be obtained, wherein the scanning unit is located on the optical path of the emission beam and the detection beam and is used for increasing the scanning angle to obtain a larger field angle.
Lidar generally employs TOF principles for ranging. The laser emitter is a laser diode, the laser diode is driven by a narrow pulse driving technology, and a large current flows in a short time to generate instantaneous high peak power for forming laser. However, when a laser diode generates a transient large current, electromagnetic interference may be generated on the detector, so that an error of a detection signal received by the detector is large.
Disclosure of Invention
Therefore, it is necessary to provide an off-axis lidar for solving the problem that the error of the detection signal received by the detector is large.
An iso-axial lidar comprising:
the transmitting unit comprises a laser transmitter, and the laser transmitter is used for generating a transmitting light beam;
the scanning unit is arranged on one side of the emitting unit along the second direction, deflects the emitting light beam emitted by the emitter and enables the emitting light beam to emit to a target object; and
the receiving unit comprises a detector and a condenser lens group, the detector is located on one side of the laser emitter along a first direction, the condenser lens group is located between the scanning unit and the detector, the focal position of the condenser lens group is located on one side, away from the laser emitter, of a main optical axis of the condenser lens group, the detector is located at the focal position of the condenser lens group, the condenser lens group receives a detection beam reflected by a target object and converges the detection beam to the detector, and the first direction is perpendicular to the second direction.
In one embodiment, the condenser lens group includes an optical pyramid and a biconic lens, which are respectively disposed on the probe beam along a second direction; and the thickness of the optical pyramid in the second direction gradually increases along the direction from the laser emitter to the detector.
In one embodiment, the biconic lens is disposed on a side of the optical pyramid away from the detector, and a side of the biconic lens away from the optical pyramid is a biconic surface.
In one embodiment, a cross-section of the condenser lens group in the second direction is arcuate in shape.
In one embodiment, the scanning unit includes a power mechanism and a mirror, the power mechanism is configured to drive the mirror to rotate, a reflection surface of the mirror is disposed at an angle to the first direction, and the mirror is configured to receive the emission beam and reflect the emission beam to a target object.
In one embodiment, the rotation center of the reflector is located on an extension line of a main optical axis of the condenser lens group.
In one embodiment, the laser radar further includes a light-transmitting housing, and the transmitting unit, the receiving unit, and the scanning unit are located in the light-transmitting housing.
In one embodiment, the inner wall of the light-transmitting outer cover is a curved surface structure.
In one embodiment, the emission unit further includes a collimating lens located on a path of the emission beam and disposed between the laser emitter and the scanning unit.
In one embodiment, the cross section of the collimating lens along the second direction is a rectangular structure, the fast axis direction of the laser emitter is along the long side direction of the rectangular structure, and the slow axis direction of the laser emitter is along the short side direction of the rectangular structure.
In the above-mentioned off-axis lidar, the condensing lens group is disposed between the scanning unit and the detector, so that the detection beam from the scanning unit can be converged onto the detector through the condensing lens group. And because the focus position of the condensing lens group deviates from the main optical axis of the condensing lens group, when the laser scanning device is in actual use, the detector can be arranged at the focus position of the condensing lens group, and meanwhile, the distance between the main optical axis of the condensing lens group and the emission unit is equal to the distance between the existing detector and the laser emitter, namely, the distance between the detection light beam irradiated on the scanning unit and the emission light beam is kept unchanged, and the size of the scanning unit can also be kept unchanged. And the focal position of the condensing lens group is positioned on one side of the main optical axis of the condensing lens group far away from the laser emitter, namely under the condition of keeping the size of the scanning unit unchanged, the distance between the laser emitter and the detector can be increased, so that the electromagnetic interference on the detector when the laser diode generates instantaneous large current is reduced, and the detection precision is increased.
Drawings
FIG. 1 is a schematic diagram of an internal structure of an off-axis lidar in an embodiment;
FIG. 2 is an internal schematic view of an off-axis lidar;
FIG. 3 is a schematic structural diagram of a condenser lens assembly;
fig. 4 is an external structural diagram of the anisometric lidar.
Reference numerals: 100-a transmitting unit; 110-a laser emitter; 120-a collimating lens;
200-a receiving unit; 210-a detector; 220-a condenser lens group; 221-biconic lens; 222-optical pyramid;
300-a scanning unit; 310-a power mechanism; 320-a mirror;
400-a light-transmissive envelope; 410-a mounting seat; 420-upper cover.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will recognize without departing from the spirit and scope of the present invention.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.
Referring to fig. 1 and 2, an embodiment of the present invention provides an iso-axis lidar including a transmitting unit 100, a receiving unit 200, and a scanning unit 300.
The transmitting unit 100 comprises a laser emitter 110, the laser emitter 110 being configured to generate an emission beam. The scanning unit 300 is disposed at one side of the laser emitter 110 along the second direction OY, and the scanning unit 300 deflects the emission beam emitted by the laser emitter 110, so that the emission beam is reflected to the target object in different directions, thereby implementing laser scanning.
The receiving unit 200 includes a detector 210 and a condenser lens group 220, the detector 210 is located at a side of the laser emitter 110 along the first direction OX, the condenser lens group 220 is located between the scanning unit 300 and the detector 210, a focal position of the condenser lens group 220 is located at a side of a main optical axis of the condenser lens group 220 away from the laser emitter 110, and the detector 210 is located at a focal position of the condenser lens group 220. The emission beam can be reflected by the target object after irradiating the target object, the detection beam reflected by the target object is reflected to the condensing lens group 220 through the scanning unit 300, the condensing lens group 220 receives the detection beam reflected by the target object and converges the detection beam to the detector 210, and the detector 210 compares the emission beam with the detection beam, so that the related information of the target, such as the distance, the direction, the height, the speed, the posture, even the shape and other parameters of the target, can be obtained. Wherein the first direction OX is perpendicular to the second direction OY. The first direction OX may be a horizontal direction and the second direction OY a vertical direction.
By providing the condensing lens group 220, the condensing lens group 220 is disposed between the scanning unit 300 and the detector 210, and thus the probe beam from the scanning unit 300 can pass through the condensing lens group 220 to be condensed onto the detector 210. In practical use, the detector 210 may be disposed at the focal position of the condenser lens group 220, and the distance between the main optical axis of the condenser lens group 220 and the emission unit 100 is equal to the distance between the existing detector 210 and the laser emitter 110, that is, the distance between the emission beam and the detection beam irradiated on the scanning unit 300 is kept constant, and the size of the scanning unit 300 is also kept constant. And because the focal position of the condenser lens group 220 is located on the side of the main optical axis of the condenser lens group 220 away from the laser emitter 110, that is, under the condition that the size of the scanning unit 300 is not changed, the distance between the laser emitter 110 and the detector 210 can be increased, so as to reduce the electromagnetic interference generated on the detector 210 when the laser diode generates instantaneous large current, and increase the detection accuracy.
In some embodiments, the condenser lens group 220 includes an optical pyramid 222 and a biconic lens 221, the optical pyramid 222 and the biconic lens 221 are sequentially disposed on the optical path of the probe beam along the second direction OY, and the optical pyramid 222 gradually increases in thickness along the second direction OY along the direction from the laser emitter 110 to the detector 210. Where the second direction OY is the vertical direction, the thickness of the optical pyramid 222 along the second direction OY is the thickness of the optical pyramid 222 along the vertical direction.
In the present embodiment, since the thickness of the optical pyramid 222 along the second direction OY gradually increases along the direction from the laser emitter 110 to the detector 210, and the detection beam is deflected to the side where the thickness of the optical pyramid 222 is larger, that is, the detection beam is deflected to the side away from the laser emitter 110 according to the principle of refraction of light, the scanning unit 300 can realize that the detector 210 is away from the laser emitter 110 without changing the paths of the emission beam and the detection beam, that is, without increasing the size of the scanning unit 300. The biconic lens 221 is arranged to compensate for aberration caused by the optical pyramid 222, that is, the biconic lens 221 can converge the detection beams to reduce the light spot, so as to reduce the size of the receiving surface of the detector 210 and further reduce the size of the whole off-axis laser radar.
In some of these embodiments, the biconic lens 221 is disposed on a side of the optical cone 222 away from the detector 210, and a side of the biconic lens 221 away from the optical cone 222 is a biconic surface. That is, the probe beam reflected by the scanning unit 300 first passes through the converging action of the biconic lens 221, and then is deflected by the optical pyramid 222, so that the spot position is far away from the laser emitter 110, i.e., the detector 210 is far away from the laser emitter 110. Wherein the biconic lens 221 and the optical pyramid 222 may be spaced apart along the second direction OY. Alternatively, the biconic lens 221 may be integrally formed with the optical pyramid 222, and referring to fig. 3, preferably, the biconic lens 221 is integrally formed with the optical pyramid 222 for reducing assembly errors.
When the biconic lens 221 and the optical pyramid 222 are integrally disposed, a surface of the biconic lens 221 away from the optical pyramid 222 is a biconic aspheric surface, and a surface of the optical pyramid 222 away from the biconic lens 221 is a plane, a spherical surface, or an odd-order aspheric surface.
In other embodiments, it is also possible that the biconic lens is disposed on a side of the optical cone near the detector. The detection light beam reflected by the scanning unit firstly undergoes deflection through the optical pyramid and then undergoes the gathering action of the biconical lens, so that the light spot position is far away from the laser emitter, namely the detector is far away from the laser emitter.
In some embodiments, the scanning unit 300 comprises a power mechanism 310 and a mirror 320, wherein the power mechanism 310 is configured to rotate the mirror 320, a reflection surface of the mirror 320 faces the laser emitter 110 and the detector 210, and a reflection surface of the mirror 320 is disposed at an angle with respect to the first direction OX.
In this embodiment, referring to fig. 1, the off-axis lidar further includes a mounting base 410, the transmitting unit 100 and the receiving unit 200 are respectively disposed on the mounting base 410, a supporting frame 440 is further disposed on the mounting base 410, the supporting frame 440 is used for supporting the power mechanism 310 and the reflector 320, and the power mechanism 310 drives the reflector 320 to rotate.
The reflecting surface can be a plane reflecting surface, a cylindrical surface reflecting surface, a spherical surface reflecting surface, a cylindrical surface aspheric surface reflecting surface, a spherical surface aspheric surface reflecting surface, a free-form surface reflecting surface and the like. The angle between the reflecting surface and the first direction OX may be any angle between zero and 90 degrees, preferably, the angle between the reflecting surface of the mirror 320 and the first direction OX is 45 °, and 45 ° is set, so that the emitted light beam can be reflected in a wide range, and a wide scanning range can be obtained. By providing the rotatable mirror 320, the emission beam emitted by the laser emitter 110 is irradiated on the mirror 320, and the mirror 320 can reflect the emission beam in different directions, thereby achieving the scanning of the laser.
In other embodiments, the scanning unit may also be a MEMS micro-galvanometer. The MEMS micro-vibrating mirror is made of monocrystalline silicon, is an optical device for making a movable structure into a chip, and has the advantages of high reliability, small volume and light weight.
In some embodiments, the center of rotation of the mirror 320 is located on an extension of the primary optical axis of the condenser lens group 220.
In the present embodiment, the area of the mirror 320 satisfies: when the reflecting mirror 320 rotates to any angle, the reflecting mirror 320 can receive all the emitted light beams from the laser emitter 110 and all the detecting light beams reflected by the target object and capable of illuminating the condenser lens group 220. The specific shape of the mirror 320 is not limited herein.
Since the mirror 320 is disposed at an angle to the first direction OX, the mirror 320 is rotated. When the reflector 320 rotates, the detection beam from the target object is reflected to the condenser lens assembly 220 along different directions, which easily causes the center position of the light spot converged by the condenser lens assembly 220 to change, so that the detector 210 may not receive a complete light spot, and further the detection of the partial angle signal by the detector 210 is affected. The rotation center of the reflector 320 is located on the extension line of the main optical axis of the condenser lens group 220, and according to the principle of light refraction, the center position of the light spot converged by the condenser lens group 220 is not changed no matter what angle the reflector 320 rotates. When the laser radar detection device is used, the central position of the detector 210 is aligned with the central position of a light spot, and meanwhile, the receiving surface of the detector 210 is larger than the size of the light spot, so that the consistency of detection signals of the laser radar at different angles can be met.
In some embodiments, referring to fig. 2 and 4, the off-axis lidar further includes a light-transmitting housing 400 and an upper cover 420, the light-transmitting housing 400 is disposed on the mounting base 410, and the upper cover 420 is fastened to the light-transmitting housing 400, that is, the mounting base 410, the light-transmitting housing 400 and the upper cover 420 form a closed cavity, and the transmitting unit 100, the receiving unit 200 and the scanning unit 300 are disposed in the closed cavity.
Further, the inner wall of the light-transmitting housing 400 is a curved surface structure, and specifically, along the second direction OY, the inner diameter of the light-transmitting housing 400 increases gradually from the base 410 to the upper cover 420. Since the light-transmitting cover 400 is not completely light-transmitting, a part of the emitted light beam irradiated onto the light-transmitting cover 400 is directly reflected. Therefore, the inner wall of the light-transmissive cover 400 is provided as a curved structure. Due to the curvature of the curved surface structure, the return angle of the emitted light beam directly reflected by the light-transmissive cover 400 may be changed such that the portion of the light beam does not directly reach the detector 210, preventing the portion of the emitted light beam from being directly detected by the detector 210, thereby affecting the detection accuracy of the detector 210.
Further, the main optical axis of the condensing lens group 220, the central axis of the transparent housing 400, and the rotation axis of the power mechanism 310 are overlapped, so that the power mechanism 310 and the condensing lens group 220 are conveniently installed and positioned in the transparent housing 400.
In some embodiments, a cross-section of the condenser lens group 220 along the second direction OY has an arcuate shape. Specifically, the cross section of the condenser lens group 220 along the second direction OY may have a more-semicircular structure or a less-semicircular structure.
In the present embodiment, the projection of the light-transmissive cover 400 on the mount 410 is circular. Without affecting the light beam emitted by the laser emitter 110, it is preferable that the projection of the condenser lens group 220 on the mounting base 410 is a multi-semicircle structure, and the multi-semicircle structure can increase the area of the detection light beam received by the condenser lens group 220 as much as possible, thereby increasing the detection range of the detector 210.
In some embodiments, the emission unit 100 further includes a collimating lens 120, the collimating lens 120 is located at the emission side of the laser emitter 110, and the collimating lens 120 is located on the optical path of the emission light beam and is disposed between the laser emitter 110 and the scanning unit 300.
In this embodiment, the laser emitter 110 may be a laser diode, and the collimating lens 120 is disposed to collimate an output light spot of the laser diode due to a characteristic of high astigmatism of an output light of the laser diode. Specifically, one side of the collimating lens 120 close to the reflector 320 is a convex surface, and the diameter of a light spot of a light beam emitted by the laser diode is reduced after the light beam is focused and collimated by the collimating lens 120, so that the energy is concentrated, and the irradiation distance of the emitted light beam can be increased.
Further, the laser emitter 110 may be divided into a fast axis and a slow axis due to different divergence degrees in two perpendicular directions, and the divergence angle in the fast axis direction is larger than that in the slow axis direction. Therefore, in the present embodiment, the collimating lens 120 is configured as a rectangular structure, the slow axis direction of the laser emitter 110 is along the short side direction of the rectangular structure, and the fast axis direction of the laser emitter 110 is along the long side direction of the rectangular structure, so that the long side direction of the collimating lens 120 can receive a wide range of fast axis diverging beams as much as possible. That is, the cross section of the collimating lens 120 along the second direction OY is made into a rectangular shape, so as to reduce the area of the cross-sectional profile as much as possible under the premise of ensuring the light-emitting energy, thereby reducing the size of the reflector 320, and further reducing the size of the radar.
Specifically, as shown in fig. 2, the fast axis divergence angle and the slow axis divergence angle of the laser diode and the length and width of the rectangular collimator lens 120 should satisfy the following conditions:
Figure BDA0003555598070000101
Figure BDA0003555598070000102
wherein, theta1Represents the laser diode fast axis divergence angle; theta2Represents the laser diode slow axis divergence angle; l is1Represents the length of the long side of the rectangle; l is2Represents the length of the short side of the rectangle; f. oflIndicating the focal length of the collimating lens.
In summary, the present application provides the condensing lens group 220, and the condensing lens group 220 is disposed between the scanning unit 300 and the detector 210, so that the detection beam from the scanning unit 300 can pass through the condensing lens group 220 and be condensed onto the detector 210. In practical use, the detector 210 may be disposed at the focal point of the condenser lens group 220, and the distance between the main optical axis of the condenser lens group 220 and the emitting unit 100 is equal to the distance between the existing detector 210 and the laser emitter 110, that is, the distance between the detecting beam and the detecting beam irradiated on the scanning unit 300 is kept unchanged, and the size of the scanning unit 300 is also kept unchanged. And because the focal position of the condenser lens group 220 is located on the side of the main optical axis of the condenser lens group 220 away from the laser emitter 110, that is, under the condition that the size of the scanning unit 300 is not changed, the distance between the laser emitter 110 and the detector 210 can be increased, so as to reduce the electromagnetic interference generated on the detector 210 when the laser diode generates instantaneous large current, and increase the detection accuracy.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. An off-axis lidar comprising:
the transmitting unit comprises a laser transmitter, wherein the laser transmitter is used for generating a transmitting beam;
the scanning unit is arranged on one side of the emission unit along the second direction, and deflects the emission beam emitted by the laser emitter to enable the emission beam to emit to a target object; and
the receiving unit comprises a detector and a condenser lens group, the detector is located on one side of the laser emitter along a first direction, the condenser lens group is located between the scanning unit and the detector, the focal point of the condenser lens group is located on one side, away from the laser emitter, of the main optical axis of the condenser lens group, the detector is located at the focal point of the condenser lens group, the condenser lens group receives a detection light beam reflected by a target object and converges the detection light beam to the detector, and the first direction is perpendicular to the second direction.
2. The iso-axial lidar of claim 1, wherein the condenser lens group comprises an optical pyramid and a biconic lens disposed in sequence along the second direction on the optical path of the probe beam; and the thickness of the optical pyramid in the second direction gradually increases along the direction from the laser emitter to the detector.
3. The iso-axial lidar of claim 2, wherein the biconic lens is disposed on a side of the optical pyramid away from the detector, and a side of the biconic lens away from the optical pyramid is biconic.
4. The iso-axial lidar of claim 1, wherein a cross-section of the condenser lens group in the second direction is arcuate in shape.
5. The off-axis lidar of claim 1, wherein the scanning unit comprises a power mechanism and a mirror, the power mechanism is configured to drive the mirror to rotate, a reflective surface of the mirror is disposed at an angle to the first direction, and the mirror is configured to receive the emitted light beam and reflect the emitted light beam to a target object.
6. The anisometric lidar of claim 5, wherein the center of rotation of said mirror is located on an extension of a main optical axis of said condenser lens group.
7. The iso-axial lidar of claim 1, further comprising a light-transmissive housing, the transmitting unit, the receiving unit, and the scanning unit being positioned within the light-transmissive housing.
8. The iso-axial lidar of claim 7, wherein the inner wall of the light transmissive enclosure is a curved structure.
9. The iso-axial lidar of claim 1, wherein the transmitting unit further comprises a collimating lens positioned on an optical path of the emitted beam and disposed between the laser emitter and the scanning unit.
10. The off-axis lidar of claim 9, wherein a cross section of the collimating lens in the second direction is a rectangular structure, a fast axis direction of the laser transmitter is along a long side direction of the rectangular structure, and a slow axis direction of the laser transmitter is along a short side direction of the rectangular structure.
CN202210275218.2A 2022-03-21 2022-03-21 Off-axis laser radar Pending CN114740452A (en)

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