Laser emission scanning device and laser radar system

Abstract

The invention relates to the technical field of laser equipment, and discloses a laser emission scanning device and a laser radar system.The laser emission scanning device comprises a plurality of light sources which are arranged at intervals in the light emitting direction of the light sources or arranged at intervals at angles along arcs with openings deviating from the light emitting faces of the light sources and used for outputting a plurality of laser beams; the light beam shaping unit is arranged on the light emitting sides of the multiple light sources and used for shaping the multiple laser beams into multiple linear light beams separated from one another, the laser beams correspond to the linear light beams one to one, and an included angle is formed between every two adjacent linear light beams; the scanning unit is arranged on the side, away from the light source, of the light beam shaping unit and used for receiving the multiple linear light beams shaped by the light beam shaping unit and reflecting the multiple linear light beams to a target detection area through rotary scanning. Through the above mode, the structure of the laser radar is simplified and the size of the laser radar is reduced while the wide-range scanning field of view of the laser radar is satisfied.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser equipment technology, and specifically to a laser emission scanning device and a laser radar system. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. A wide detection range is its important indicator.

[0003] In the prior art, laser radar generally adopts a point scanning and splicing method to achieve a wide range of scanning field of view. Specifically, the laser radar uses multiple laser transceivers arranged at an angle in space, and cooperates with a scanning mirror array to splice multiple small fields of view scanned separately by laser beams output by multiple laser emitting devices into a large field of view, thereby realizing a wide range of scanning field of view of the laser radar. However, the laser radar that uses multiple laser transceivers in conjunction with a scanning mirror array to achieve large field of view scanning not only has a complex system structure, but also has a large size and high production cost. Summary of the invention

[0004] In view of the above problems, the embodiments of the present application provide a laser emission scanning device and a laser radar system, which simplifies the structure of the laser radar and reduces the size of the laser radar while meeting the large-range scanning field of view of the laser radar.

[0005] According to one aspect of an embodiment of the present application, a laser emitting scanning device is provided, which includes: a plurality of light sources, which are arranged at intervals along their light emitting directions or at intervals along an arc of an opening away from a light emitting surface of the light source, for outputting a plurality of laser beams; a beam shaping unit, which is arranged on the light emitting side of the plurality of light sources, for shaping the plurality of laser beams into a plurality of mutually separated line beams, wherein the laser beams correspond to the line beams one-to-one, and angles are formed between adjacent line beams; a scanning unit, which is arranged on a side of the beam shaping unit away from the light source, for receiving the plurality of line beams shaped by the beam shaping unit, and rotating and scanning to reflect the plurality of line beams to a target detection area.

[0006] In an optional manner, the angles between adjacent line light beams are equal and equal to a first preset angle; the scanning unit is used to rotate and scan a second preset angle to reflect multiple line light beams to a target detection area, wherein the second preset angle is greater than or equal to the first preset angle.

[0007] In an optional manner, when the multiple light sources are arranged at a first preset distance along the direction of their light emitting fast axes, the multiple light sources are arranged along their optical axes, and adjacent light sources are arranged at a second preset distance along the direction of the optical axes.

[0008] In an optional manner, the beam shaping unit includes a microlens array and a fast-axis collimating lens group; the microlens array is arranged on the light-emitting side of the multiple light sources, and is used to homogenize the multiple laser beams in the slow-axis direction; the fast-axis collimating lens group is arranged between the microlens array and the multiple light sources or on the side of the microlens array away from the multiple light sources, and is used to perform angular deflection and divergence angle collimation on the multiple laser beams or the homogenized laser beams in the fast-axis direction before emitting.

[0009] In an optional manner, the laser emitting scanning device also includes a beam expander lens group; the beam expander lens group is arranged on one side of the scanning unit reflecting the line light beam, and is used to expand the angle between adjacent line light beams reflected by the scanning unit and then emit them to the target detection area.

[0010] According to one aspect of an embodiment of the present application, a laser radar system is provided, comprising: a laser emission scanning device provided in any of the above embodiments and a receiving device for receiving a light beam reflected from a target detection area.

[0011] In an optional manner, the receiving device is disposed at one end of the scanning unit along the slow axis direction of the laser beam.

[0012] In an optional manner, the receiving device includes a wide-angle lens group and an array detector; the wide-angle lens group is arranged at one end of the scanning unit along the slow axis direction, and is used to converge the light beam reflected from the target detection area; the array detector is arranged on the side of the wide-angle lens group away from the target detection area, and is used to receive the light beam converged by the wide-angle lens group.

[0013] In an optional manner, the receiving device and the beam shaping unit are arranged on the same side of the scanning unit, and the distance between the receiving device and the target detection area is smaller than the distance between the beam shaping unit and the target detection area; the scanning unit is also used to receive the light beam reflected by the target detection area and reflect the reflected light beam to the receiving device; the receiving device is used to receive the reflected light beam.

[0014] In an optional manner, when the laser emission scanning device also includes a beam expander lens group, the beam expander lens group is also used to converge the light beam reflected from the target detection area; the scanning unit is also used to receive the light beam converged by the beam expander lens group and reflect the converged light beam to the receiving device; the receiving device is also used to receive the converged light beam.

[0015] In an optional manner, the receiving device includes a wide-angle lens group and an array detector; the wide-angle lens group and the beam shaping unit are arranged on the same side of the scanning unit, and the distance between the wide-angle lens group and the target detection area is smaller than the distance between the beam shaping unit and the target detection area; the wide-angle lens group is used to converge the reflected light beam; the array detector is arranged on the side of the wide-angle lens group away from the scanning unit, and is used to receive the light beam converged by the wide-angle lens group.

[0016] In the laser emitting scanning device of the present application, by arranging multiple light sources at intervals or at interval angles, a beam shaping unit arranged on the light emitting side of the light source can shape multiple laser beams into multiple line beams that are separated from each other and form an angle with each other, and by the rotation scanning of a scanning unit arranged on the light emitting side of the beam shaping unit, the received multiple line beams are reflected to the target detection area, so that the multiple line beams in the target detection area can be spliced ​​through the small-range scanning field of view of each line beam to achieve a large-range scanning field of view. In the above manner, a laser emitting scanning device is used, and by cooperating with a receiving device for receiving reflected light, the structure of the laser radar can be simplified and the volume of the laser radar can be reduced while meeting the large-range scanning field of view of the laser radar, thereby reducing the cost of the laser radar.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0019] Figure 1 A schematic diagram of the optical path structure of a laser emitting scanning device provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of the optical path structure of a light source provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of the optical path structure of a light source provided in another embodiment of the present application;

[0022] Figure 4 A schematic diagram of the optical path structure of a light source provided in another embodiment of the present application;

[0023] Figure 5 The scanning field of view of the laser emission scanning device provided in the embodiment of the present application;

[0024] Figure 6 A schematic diagram of the optical path structure of a light source provided in an embodiment of the present application;

[0025] Figure 7A schematic diagram of the optical path structure of a light source and a beam shaping unit provided in an embodiment of the present application;

[0026] Figure 8 A schematic diagram of the optical path structure of a laser emitting scanning device provided in an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of the front view structure of the laser radar system provided in an embodiment of the present application;

[0028] Fig.10 A schematic diagram of the optical path structure of a laser radar system provided in another embodiment of the present application;

[0029] Fig.11 A schematic diagram of the side view structure of a scanning unit and a receiving device provided in an embodiment of the present application.

[0030] The reference numerals in the specific implementation manner are as follows:

[0031] 10. LiDAR system;

[0032] 20. Target detection area; 21. Local scanning area;

[0033] 100, laser emission scanning device; 110, light source; 120, beam shaping unit; 121, microlens array; 122, fast axis collimating lens group; 130, scanning unit; 140, beam expanding lens group;

[0034] 200. Receiving device; 210. Wide-angle lens group; 220. Area array detector. DETAILED DESCRIPTION

[0035] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0037] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0038] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0040] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0041] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0042] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0043] LiDAR is a radar system that emits laser beams to detect target characteristics such as position and speed. Its working principle is to first emit a detection laser beam to the target, and then compare the received signal reflected from the target with the transmitted signal. After appropriate processing, relevant information about the target can be obtained, such as target distance, direction, altitude, speed, attitude, and even shape parameters, so as to detect, track and identify the target.

[0044] FOV (Field of View) range is an important indicator of LiDAR products. In the prior art, LiDAR generally uses point scanning and splicing to achieve a wide range of scanning field of view. Specifically, LiDAR uses multiple laser emitting devices and multiple laser receiving devices (collectively referred to as laser transceivers), and multiple laser transceivers are arranged at angles in space, and cooperate with the scanning mirror array to scan multiple fixed small fields of view separately with the laser beams output by multiple laser emitting devices, and then use the two-dimensional scanning function of the scanning mirror to splice multiple small fields of view into a large field of view, so as to achieve a wide range of scanning field of view of LiDAR. However, LiDAR that uses multiple laser transceivers and scanning mirror arrays to achieve large field of view scanning not only has a complex system structure, but also has a large volume and high production cost.

[0045] Based on this, an embodiment of the present application provides a laser emitting scanning device, which arranges multiple light sources and cooperates with a beam shaping unit to output multiple line light beams that are separated from each other and form an angle, and realizes the splicing of multiple line light beams in a small field of view in the target detection area through the rotation scanning of the scanning unit. Therefore, by adopting a laser emitting scanning device and cooperating with a receiving device for receiving reflected light, the structure of the laser radar can be simplified and the volume of the laser radar can be reduced while meeting the large-range scanning field of view of the laser radar, thereby reducing the cost of the laser radar.

[0046] See also Figure 1-Figure 4 , Figure 1 The optical path structure schematic diagram of the laser emitting scanning device provided in the embodiment of the present application is shown. Figure 2-Figure 4 Schematic diagrams of the optical path structures of light sources provided in several embodiments of the present application are shown, wherein: Figure 1The x-axis direction is the slow axis direction of the laser beam, the y-axis direction is the fast axis direction of the laser beam, the z-axis direction is the optical path direction, and the z-axis direction is perpendicular to the x-axis direction and the y-axis direction. As shown in the figure, the laser emission scanning device 100 includes: a light source 110, a beam shaping unit 120 and a scanning unit 130. Multiple light sources 110 are arranged at intervals along their light-emitting directions or at angles along the arcs of the openings away from the light-emitting surfaces of the light sources 110, for outputting multiple laser beams. The beam shaping unit 120 is arranged on the light-emitting side of the multiple light sources 110, and is used to shape the multiple laser beams into multiple separated line beams, wherein the laser beams correspond to the line beams one by one, and an angle is formed between adjacent line beams. The scanning unit 130 is arranged on the side of the beam shaping unit 120 away from the light source 110, and is used to receive the multiple line beams shaped by the beam shaping unit 120, and rotate and scan to reflect the multiple line beams to the target detection area 20.

[0047] In the embodiment of the present application, the fast axis direction of the light source 110 is the fast axis direction of the laser beam output by it (the y-axis direction in the figure). Specifically, the plurality of light sources 110 may be arranged at intervals along the slow axis direction, or may be arranged at intervals along the slow axis direction. Figure 1 The spacing distance along the fast axis direction is shown. Figure 1 The distance between the multiple light sources 110 along the fast axis is only used as an example for explanation, which does not constitute a limitation on the present application. The distances between adjacent light sources 110 may be equal or unequal. Figure 1 The adjacent light sources 110 shown in FIG. 1 are spaced apart by a distance d; the plurality of light sources 110 may also be Figure 2-Figure 4 As shown, the light sources 110 are arranged at intervals along the arc, wherein the angles formed between adjacent light sources 110 may be equal or unequal, for example, Figure 2 As shown, they are arranged at a preset angle α1 along the arc line S1, or, Figure 3 The light sources 110 are arranged at a preset angle α2 along the arc S2, or at a preset angle α3 along the arc S3. The above arrangement of the light sources 110 is not only beneficial for heat dissipation of each light source 110, but also allows the multiple light sources 110 to output multiple laser beams to the beam shaping unit 120.

[0048] The beam shaping unit 120 is arranged on the light-emitting side of the plurality of light sources 110, so that the beam shaping unit 120 can change the emission angle of the laser beam output by each light source 110 to achieve the deflection of the laser beam, thereby shaping each laser beam into a line beam. Specifically, the laser beam corresponds to the line beam one by one, that is, when the number of light sources 110 is 3 and 3 laser beams are output, 3 line beams can be obtained after being shaped by the beam shaping unit 120; when the number of light sources 110 is 5 and 5 laser beams are output, 5 line beams can be obtained after being shaped by the beam shaping unit 120. Figure 1 Only three light sources 110 are used as an example for illustration, which does not constitute a limitation to the present application.

[0049] When the beam shaping unit 120 shapes the multiple laser beams output by the multiple light sources 110 arranged as above, multiple separated line beams can be obtained, and an angle is formed between any two adjacent line beams, and the angles between adjacent line beams can be equal or unequal, wherein, Figure 1 The angles between adjacent line beams are equal. Taking the interval between any two adjacent light sources 110 being equal and equal to d, and the focal length f of the beam shaping unit 120 as an example, after the beam shaping unit 120 shapes the multiple laser beams, the interval distance d, the focal length f and the angle θ between the adjacent line beams satisfy the formula: d=f·tan(θ).

[0050] The scanning unit 130 is a MEMS scanning mirror (Micro-Electro-Mechanical System Scanning Mirror) that can realize one-dimensional scanning, two-dimensional scanning or three-dimensional scanning according to different vibration frequencies. In the embodiment of the present application, the one-dimensional scanning function of the scanning unit 130 is mainly used. The scanning unit 130 is arranged on the light-emitting side of the beam shaping unit 120, so that the scanning unit 130 can receive multiple line beams emitted after shaping by the beam shaping unit 120, and reflect the multiple line beams, thereby changing the optical path direction of each line beam to reflect to the target detection area 20, thereby realizing scanning of the target detection area 20. Since the multiple line beams output by the beam shaping unit 120 are separated from each other, and the adjacent line beams form an angle, there is still an angle between the adjacent line beams after being reflected by the scanning unit 130. When the scanning unit 130 rotates and scans, each line beam can form its corresponding scanning field of view.

[0051] Please refer to Figure 5 , Figure 5 The scanning field of view of the laser emission scanning device provided in the embodiment of the present application is shown. As shown in the figure, when the scanning unit reflects three line beams to the target detection area 20, the multiple line beams form three local scanning areas 21 (solid lines) in the target detection area 20. At this time, the area between adjacent local scanning areas 21 belongs to the field of view scanned by the line beams. Figure 1 When scanning in the direction of the rotating arrow shown in FIG. 1 is counterclockwise, each line beam moves in the target detection area 20 along the z-axis direction in the figure, and each local scanning area 21 corresponding to each line beam in the target detection area 20 moves along the z-axis direction in the figure, such as moving to Figure 5The local scanning area 21 shown in the dotted part, as the scanning unit 130 rotates and scans, the local scanning area 21 corresponding to each line beam is continuously spliced, and finally forms a large-scale scanning field of view. Among them, when the scanning unit 130 rotates and scans at an angle less than the angle between any adjacent line beams, that is, less than the minimum angle between adjacent line beams, the scanning fields obtained by scanning each line beam are separated from each other, and finally form a large-scale scanning field of view with a spacing area; when the scanning unit 130 rotates and scans at an angle equal to the angle between adjacent line beams, and the angles between adjacent line beams are equal, the scanning fields of view of each line beam are equal, and finally can be completely spliced ​​into a large-scale scanning field of view; when the scanning unit 130 rotates and scans at an angle greater than or equal to the angle between any adjacent line beams, that is, greater than or equal to the minimum angle between adjacent line beams, the scanning fields of view of each line beam overlap, and finally can form a large-scale scanning field of view with an overlapping area.

[0052] In the laser emitting scanning device 100 of the present application, by arranging multiple light sources 110 at intervals or at interval angles, the beam shaping unit 120 arranged on the light emitting side of the light source 110 can shape multiple laser beams into multiple line beams that are separated from each other and form an angle with each other, and through the rotation scanning of the scanning unit 130 arranged on the light emitting side of the beam shaping unit 120, the received multiple line beams are reflected to the target detection area 20, so that the multiple line beams in the target detection area 20 can be stitched through the small-range scanning field of view of each line beam to achieve a large-range scanning field of view. In the above manner, a laser emitting scanning device 100 is used, and by cooperating with a receiving device for receiving reflected light, the structure of the laser radar can be simplified and the volume of the laser radar can be reduced while satisfying the large-range scanning field of view of the laser radar, thereby reducing the cost of the laser radar.

[0053] In order to improve the reliability of the laser radar, this application further proposes an implementation method, please continue to refer to Figure 1 and Figure 5 , the angles between adjacent line beams are equal and equal to the first preset angle. The scanning unit 130 is used to rotate and scan at a second preset angle to reflect multiple line beams to the target detection area 20, wherein the second preset angle is greater than or equal to the first preset angle.

[0054] When the angles between any adjacent line beams among the multiple line beams output after shaping by the beam shaping unit 120 are equal and equal to the first preset angle θ, the angles between adjacent line beams reflected by the scanning unit 130 to the target detection area 20 are also equal to the first preset angle θ, and the sizes of the fields of view to be scanned between the line beams are equal, i.e., equal field of view scanning.

[0055] When the second preset angle β is equal to the first preset angle θ, after the scanning unit 130 rotates counterclockwise to scan the second preset angle β, the scanning fields of view of each line light beam can be spliced ​​into a large-range scanning field of view; when the second preset angle β is greater than the first preset angle θ, after the scanning unit 130 rotates counterclockwise to scan the second preset angle β, the scanning fields of view of each line light beam overlap, and finally a large-range scanning field of view with an overlapping area is formed.

[0056] For example, the laser emitting scanning device 100 is to achieve the following Figure 5 In the scanning field of view of 120°×25° shown in the figure, if the angular space in the z-axis direction is -60°~60°, and the angular space in the x-axis direction is -12.5°~12.5°, when the number of line beams is 3, the first preset angle θ is 40°, and the second preset angle β is also 40°, then after the scanning unit 130 rotates counterclockwise to scan 40°, the scanning fields of view of each line beam can be spliced ​​to achieve a scanning field of view of 120°×25°; when the number of line beams is 5, the first preset angle θ is 40°, and the second preset angle β is also 40°. θ is 24°, and the second preset angle β is also 24°. After the scanning unit 130 rotates counterclockwise to scan 24°, the scanning fields of view of each line light beam can be spliced ​​to achieve a scanning field of view of 120°×25°; when the number of line light beams is 5 and the first preset angle θ is 24°, the second preset angle β is set to 30°. After the scanning unit 130 rotates counterclockwise to scan 30°, the fields of view scanned by adjacent line light beams overlap, and after splicing, a scanning field of view of 126°×25° can be achieved.

[0057] By outputting multiple line light beams with equal included angles between adjacent line light beams, and rotating the scanning unit 130 to scan at an angle greater than or equal to the included angle, not only can equal-field-of-view scanning of each line light beam be achieved, but the scanning fields of view of each line light beam can also be spliced ​​into a complete large-range scanning field of view, thereby improving the reliability of the laser radar.

[0058] In order to compensate for the back focus variation caused by the spacing of the multiple light sources 110, the present application further proposes an implementation method, see Figure 6 , Figure 6 A schematic diagram of the optical path structure of the light source provided in an embodiment of the present application is shown. When a plurality of light sources 110 are arranged at a first preset distance along the direction of their light emitting fast axis, the plurality of light sources 110 are arranged along their optical axis direction (z-axis direction in the figure), and adjacent light sources 110 are arranged at a second preset distance along the direction of the optical axis. Figure 1 The arrangement of the plurality of light sources 110 spaced apart by a distance d along the slow axis is merely taken as an example for illustration, and does not constitute a limitation to the present application.

[0059] Specifically, the plurality of light sources 110 may be arranged asymmetrically along the center line of the optical axis, or may be arranged Figure 6As shown, the center lines along the optical axis are symmetrically arranged. For example, when the number of light sources 110 is an even number, the center line l is located between the optical axes of the two light sources 110 at the middle positions. When the number of light sources 110 is an odd number, the center line l is the optical axis of the light source 110 at the middle position. The figure only takes five light sources 110 as an example for illustration, which does not constitute a limitation to the present application.

[0060] Since the refraction angles of the light beam at the center and edge of the lens are different, spherical aberration may occur in the imaging. Therefore, when any two adjacent light sources 110 are spaced apart by a first preset distance d, the adjacent light sources 110 are spaced apart by a second preset distance L along the optical axis, that is, the interval between any two adjacent light sources 110 is equal to the second preset distance L, so that the divergence angle of the laser beam output by the light sources 110 on both sides of the edge when incident on the beam shaping unit 120 is smaller, thereby reducing the exit angle of the line beam, so that the angle between the laser beam output by the edge light source 110 and the laser beam output by the adjacent position light source 110 after being shaped by the beam shaping unit 120 is θ. For example, when the focal length of the beam shaping unit 120 is f, the second preset distance L satisfies the formula:

[0061]

[0062] By means of the above method, the back focus variation caused by the spacing of the multiple light sources 110 can be compensated, so that the angles between any two adjacent line beams output after shaping by the beam shaping unit 120 are equal, thereby achieving equal field of view scanning of each line beam.

[0063] In order to shape multiple laser beams into multiple line beams separated from each other and at an angle to each other, the present application further proposes an implementation method, see Figure 7 , Figure 7 The schematic diagram of the optical path structure of the light source and the beam shaping unit provided in the embodiment of the present application is shown. As shown in the figure, the beam shaping unit 120 includes a microlens array 121 and a fast-axis collimating lens group 122. The microlens array 121 is arranged on the light-emitting side of the multiple light sources 110, and is used to homogenize the multiple laser beams in the slow axis direction. The fast-axis collimating lens group 122 is arranged between the microlens array 121 and the multiple light sources 110 or on the side of the microlens array 121 away from the multiple light sources 110, and is used to deflect the multiple laser beams or the homogenized laser beams in the fast axis direction and collimate the divergence angle before emitting.

[0064] The microlens array 121 may be a conventional microlens array 121 used alone, or may be a conventional microlens array 121 symmetrical in pairs. The microlens array 121 is arranged on the light-emitting side of the plurality of light sources 110, so that the microlens array 121 can rearrange the beams in the angular space along the slow axis direction for each laser beam, and finally achieve the homogenization effect of each laser beam in the slow axis direction.

[0065] The fast axis collimating lens group 122 may use a cylindrical mirror, a plano-convex lens or a concave-convex lens, or a circular lens or a circular lens group. Specifically, the fast axis collimating lens group 122 may be disposed between the plurality of light sources 110 and the microlens array 121, and the laser beam outputted by each light source 110 may be collimated and deflected in the fast axis direction, so that the laser beam is approximately parallel in the fast axis direction, that is, emitted to the microlens array 121 with a very small beam divergence angle, and after being homogenized by the microlens array 121 in the slow axis direction, a plurality of line beams separated from each other and at an angle to each other are obtained; the fast axis collimating lens group 122 may also be disposed on the light-emitting side of the microlens array 121, and the laser beam homogenized in the slow axis direction may be collimated and deflected in the fast axis direction, so that the laser beam is approximately parallel in the fast axis direction, that is, emitted with a very small beam divergence angle, thereby obtaining a plurality of line beams separated from each other and at an angle to each other.

[0066] By means of a microlens array 121 arranged on the light-emitting side of the plurality of light sources 110, and a fast-axis collimating lens group 122 arranged between the microlens array 121 and the plurality of light sources 110 or on the light-emitting side of the microlens array 121, each laser beam can be homogenized in the slow-axis direction, and beam collimation and beam deflection can be performed in the fast-axis direction, and finally a plurality of line beams separated from each other and forming an angle between each other are output to the scanning unit 130, thereby realizing a wide range of field of view scanning under the rotation scanning of the scanning unit 130.

[0067] In order to expand the scanning field of view of each line beam, the present application further proposes an implementation method, see Figure 8 , Figure 8 The optical path structure schematic diagram of the laser emitting scanning device provided in the embodiment of the present application is shown. As shown in the figure, the laser emitting scanning device 100 further includes a beam expander group 140. The beam expander group 140 is arranged on the side of the scanning unit 130 reflecting the line beam, and is used to expand the angle between adjacent line beams reflected by the scanning unit 130 and then emit them to the target detection area 20.

[0068] The beam expander lens group 140 may use a cylindrical mirror, a meniscus lens, a plano-concave lens, a bi-concave lens, or a lens group capable of realizing a beam expansion function. The beam expander lens group 140 is arranged on the side of the scanning unit 130 reflecting the line beam, and the line beam can be deflected so that the angle between adjacent line beams increases, thereby increasing the spacing distance between each local scanning area 21 of each line beam on the target detection area 20.

[0069] Specifically, when the magnification of the beam expander group 140 is x and the angle between adjacent line beams output by the beam shaping unit 120 is θ, the angle fov between adjacent line beams output after passing through the beam expander group 140 is fov=θ·x. It can be seen that fov is the scanning field of view of each line beam after expansion by the beam expander group 140, so that each line beam emitted to the target detection area 20 can achieve the same range of scanning field of view while reducing the rotation scanning angle of the scanning unit 130, thereby reducing the movement amplitude of the scanning unit 130 and reducing the failure rate of the scanning unit 130, or, when the rotation scanning angle of the scanning unit 130 remains unchanged, the scanning field of view of each line beam is increased, so that the scanning fields of view of multiple line beams can be spliced ​​to obtain a larger range of scanning field of view.

[0070] According to another aspect of the embodiment of the present application, a laser radar system is also provided. Fig. 9 and Fig.10 , Fig. 9 FIG. 2 shows a schematic diagram of the front view structure of the laser radar system provided in an embodiment of the present application. Fig.10 A schematic diagram of the optical path structure of a laser radar system provided in another embodiment of the present application is shown, in which the dotted arrows represent the light beam reflected from the target detection area. As shown in the figure, the laser radar system 10 includes a laser emitting scanning device 100 provided in any of the above embodiments and a receiving device 200, and the receiving device 200 is used to receive the light beam reflected from the target detection area 20.

[0071] When the laser emitting scanning device 100 outputs a line light beam to the target detection area 20, the target detection area 20 reflects the light beam. After the receiving device 200 receives the light beam reflected by the target detection area 20, it detects the light beam, thereby realizing detection of the target detection area 20 and detection of a large field of view.

[0072] In the laser radar system 10 of the present application, by setting the distance or angle between the multiple light sources 110, the beam shaping unit 120 arranged on the light-emitting side of the light source 110 can shape the multiple laser beams into multiple line beams separated from each other and at an angle to each other, and by the rotation scanning of the scanning unit 130 arranged on the light-emitting side of the beam shaping unit 120, the received multiple line beams are reflected to the target detection area 20, so that the multiple line beams in the target detection area 20 can be spliced ​​through the small-range scanning field of view of each line beam to achieve a large-range scanning field of view, and finally the light beam reflected from the target detection area 20 is received and detected by the receiving device 200, thereby realizing the target detection function of the laser radar system 10. In the above manner, by using a laser emitting scanning device 100 and a receiving device 200, the structure of the laser radar system 10 can be simplified and the volume of the laser radar system 10 can be reduced while satisfying the large-range scanning field of view of the laser radar system 10, thereby reducing the cost of the laser radar system 10.

[0073] In order to reduce the lateral area of ​​the laser radar system 10, the present application further proposes an implementation method, please continue to refer to Fig. 9 The receiving device 200 is disposed at one end of the scanning unit 130 along the slow axis direction of the laser beam.

[0074] Specifically, the receiving device 200 is disposed on one side or the other side of the scanning unit 130 along the x-axis direction (for example Fig. 9 As shown above or below), and ensuring that the receiving device 200 can receive the light beam reflected by the target detection area 20, the lateral area of ​​the laser radar system 10 along the optical axis can be reduced while ensuring the reliability of the laser radar system 10. Fig. 9 The example in which the receiving device 200 is disposed above the scanning unit 130 along the x-axis direction is used for illustration only, and does not constitute a limitation to the present application.

[0075] In order to achieve wide-range field of view detection of laser radar, this application further proposes an implementation method, please continue to refer to Fig. 9 , and combined with Fig.11 , Fig.11 A schematic diagram of the side structure of a scanning unit and a receiving device provided in an embodiment of the present application is shown. Fig.11 Compared with the receiving device and scanning unit Fig. 9The receiving device 200 is placed 90° counterclockwise in the plane where the y-axis and the z-axis are located. As shown in the figure, the receiving device 200 includes a wide-angle lens group 210 and a planar array detector 220. The wide-angle lens group 210 is arranged at one end of the scanning unit 130 along the slow axis direction, and is used to converge the light beam reflected from the target detection area 20. The planar array detector 220 is arranged on the side of the wide-angle lens group 210 away from the target detection area 20, and is used to receive the light beam converged by the wide-angle lens group 210.

[0076] It should be noted that the wide-angle lens group 210 used in this example can be an existing wide-angle lens group, which is composed of a series of lenses and can converge the light beam reflected by the target detection area 20. Specifically, the wide-angle lens group 210 is arranged at one end of the scanning unit 130 along the slow axis direction, that is, the wide-angle lens group 210 is arranged above the scanning unit 130 along the x-axis direction (such as Fig.11 The wide-angle lens group 210 is positioned at the side of the wide-angle lens group 210 away from the target detection area 20, so that the area array detector 220 can receive the light beam shaped and converged by the wide-angle lens group 210, and detect the light beam, so as to realize the detection of the target detection area 20 and the detection of a wide range of field of view.

[0077] In order to reduce the volume of the laser radar system 10, the present application further proposes an implementation method, please continue to refer to Fig.10 , the receiving device 200 and the beam shaping unit 120 are arranged on the same side of the scanning unit 130, and the distance between the receiving device 200 and the target detection area 20 is smaller than the distance between the beam shaping unit 120 and the target detection area 20. The scanning unit 130 is also used to receive the light beam reflected by the target detection area 20 and reflect the reflected light beam to the receiving device 200. The receiving device 200 is used to receive the reflected light beam.

[0078] Specifically, the receiving device 200 is arranged on one side of the scanning unit 130, and is located on the same side of the scanning unit 130 as the beam shaping unit 120, and the distance between the receiving device 200 and the target detection area 20 is smaller than the distance between the beam shaping unit 120 and the target detection area 20. When a scanning unit 130 with a larger area is arranged, the line beam output after shaping by the beam shaping unit 120 and the beam reflected by the target detection area 20 can be received in different areas of the scanning unit 130, and the beam reflected by the target detection area 20 can be reflected to the receiving device 200, so that the scanning unit 130 continuously reflects the beam reflected by the target detection area 20 to the receiving device 200 during the rotation scanning process, and the receiving device 200 detects the beam. In this way, the structure of the laser radar system 10 can be made more compact, thereby reducing the volume of the laser radar system 10 while ensuring the detection performance of the laser radar system 10.

[0079] In order to reduce the size of the receiving device 200, the present application further proposes an implementation method, please continue to refer to Fig.10 When the laser emitting scanning device 100 further includes a beam expander lens group 140, the beam expander lens group 140 is also used to converge the light beam reflected from the target detection area 20. The scanning unit 130 is also used to receive the light beam converged by the beam expander lens group 140 and reflect the converged light beam to the receiving device 200. The receiving device 200 is also used to receive the converged light beam.

[0080] When the laser emitting scanning device 100 also includes a beam expander lens group 140, that is, the beam expander lens group 140 is arranged on a side of the line light beam reflected by the scanning unit 130, the beam expander lens group 140 can receive the light beam reflected by the target detection area 20, and can converge the reflected light beam and output it to the scanning unit 130, thereby reducing the angle between the reflected light beams. Therefore, when the scanning unit 130 receives the converged light beam and rotates and scans to reflect the light beam, the receiving device 200 using a small field of view can receive the light beam reflected by the scanning unit 130, thereby achieving the purpose of reducing the volume of the receiving device 200.

[0081] In order to achieve wide-range field of view detection of laser radar, this application further proposes an implementation method, please continue to refer to Fig.10The receiving device 200 includes a wide-angle lens group 210 and an array detector 220. The wide-angle lens group 210 and the beam shaping unit 120 are arranged on the same side of the scanning unit 130, and the distance between the wide-angle lens group 210 and the target detection area 20 is smaller than the distance between the beam shaping unit 120 and the target detection area 20. The wide-angle lens group 210 is used to converge the reflected light beam. The array detector 220 is arranged on the side of the wide-angle lens group 210 away from the scanning unit 130, and is used to receive the light beam converged by the wide-angle lens group 210.

[0082] It should be noted that the specific implementation process and beneficial effects of the wide-angle lens group 210 and the area array detector 220 used in this example can be referred to in the aforementioned Fig.11 The wide-angle lens assembly 210 and the area array detector 220 of the illustrated embodiment are not described in detail herein.

[0083] The positions of the wide-angle lens group 210 and the array detector 220 in the laser radar system 10 of this example are similar to those in the above Fig.11 The difference between the positions of the wide-angle lens group 210 and the array detector 220 in the laser radar system 10 of the embodiment shown is that the wide-angle lens group 210 is arranged on one side of the scanning unit 130, and is located on the same side of the scanning unit 130 as the beam shaping unit 120, and the distance between the wide-angle lens group 210 and the target detection area 20 is smaller than the distance between the beam shaping unit 120 and the target detection area 20, so that a larger area of ​​the scanning unit 130 can be arranged to receive the beam shaped by the beam shaping unit 120 in different areas. The rear output line light beam and the light beam reflected by the target detection area 20 enable the scanning unit 130 to continuously reflect the light beam reflected by the target detection area 20 to the wide-angle lens group 210 during the rotational scanning process, so that the wide-angle lens group 210 can receive the light beam reflected by the target detection area 20, and shape the reflected light beam and converge it onto the area array detector 220 arranged on the side of the wide-angle lens group 210 away from the scanning unit 130, so as to detect the light beam and realize the detection of the target detection area 20 and the detection of a wide field of view.

Claims

1. A laser emitting scanning device, characterized in that: The laser emitting scanning device comprises: A plurality of light sources, the plurality of light sources are arranged at intervals along the light emitting direction thereof or at intervals along the arc of the opening away from the light emitting surface of the light source, for outputting a plurality of laser beams; A beam shaping unit, disposed on the light-emitting side of the plurality of light sources, for shaping the plurality of laser beams into a plurality of mutually separated line beams, wherein the laser beams correspond to the line beams one by one, and adjacent line beams form an angle between each other; The scanning unit is arranged on a side of the beam shaping unit away from the light source, and is used to receive the multiple line light beams shaped by the beam shaping unit, and to rotate and scan to reflect the multiple line light beams to a target detection area.

2. The laser emitting scanning device according to claim 1, characterized in that: The included angles between adjacent line light beams are equal, and the included angles are equal to a first preset angle; The scanning unit is used for rotating and scanning at a second preset angle to reflect the plurality of line light beams to a target detection area, wherein the second preset angle is greater than or equal to the first preset angle.

3. The laser emitting scanning device according to claim 1, characterized in that: When the plurality of light sources are arranged at a first preset distance along the direction of the light emitting fast axis, the plurality of light sources are arranged along the direction of the optical axis, and adjacent light sources are arranged at a second preset distance along the direction of the optical axis.

4. The laser emitting scanning device according to claim 1, characterized in that: The beam shaping unit includes a microlens array and a fast axis collimating lens group; The microlens array is arranged on the light-emitting side of the plurality of light sources, and is used to perform homogenization processing on the plurality of laser beams in the slow axis direction; The fast axis collimating lens group is arranged between the microlens array and the multiple light sources or on the side of the microlens array away from the multiple light sources, and is used to deflect the multiple laser beams or the homogenized laser beams in the fast axis direction and collimate the divergence angle before emitting.

5. The laser emitting scanning device according to claim 1, characterized in that: The laser emission scanning device also includes a beam expander lens group; The beam expander group is arranged on a side of the scanning unit reflecting the line light beam, and is used to expand the angle between adjacent line light beams reflected by the scanning unit and then emit them to the target detection area.

6. A laser radar system, characterized in that: The laser radar system comprises: a laser emitting scanning device as described in any one of claims 1 to 5; and A receiving device is used to receive the light beam reflected by the target detection area.

7. The laser radar system according to claim 6, characterized in that: The receiving device is arranged at one end of the scanning unit along the slow axis direction of the laser beam.

8. The laser radar system according to claim 7, characterized in that: The receiving device includes a wide-angle lens group and an array detector; The wide-angle lens group is arranged at one end of the scanning unit along the slow axis direction, and is used to converge the light beam reflected by the target detection area; The area array detector is arranged on a side of the wide-angle lens group away from the target detection area, and is used to receive the light beam converged by the wide-angle lens group.

9. The laser radar system according to claim 6, characterized in that: The receiving device and the beam shaping unit are arranged on the same side of the scanning unit, and the distance between the receiving device and the target detection area is smaller than the distance between the beam shaping unit and the target detection area; The scanning unit is also used to receive the light beam reflected by the target detection area and reflect the reflected light beam to the receiving device; The receiving device is used to receive the reflected light beam.

10. The laser radar system according to claim 9, characterized in that: When the laser emitting scanning device further includes a beam expanding lens group, the beam expanding lens group is also used to converge the light beam reflected by the target detection area; The scanning unit is also used to receive the light beam converged by the beam expander group and reflect the converged light beam to the receiving device; The receiving device is also used to receive the converged light beam.

11. The laser radar system according to claim 9, characterized in that: The receiving device includes a wide-angle lens group and an array detector; The wide-angle lens group and the beam shaping unit are arranged on the same side of the scanning unit, and the distance between the wide-angle lens group and the target detection area is smaller than the distance between the beam shaping unit and the target detection area; The wide-angle lens group is used to converge the reflected light beam; The area array detector is arranged on a side of the wide-angle lens group away from the scanning unit, and is used to receive the light beam converged by the wide-angle lens group.

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