Laser radar

Abstract

The utility model discloses a laser radar, comprising an optical scanning module comprising a transmission scanning unit and a reflection scanning unit; the hollow rotating body supports and drives the optical scanning module to rotate; the transmitting-receiving lens group supports the lens cone and extends into the hollow rotating body; the first lens group is arranged in the transmitting-receiving lens group supporting lens barrel; the second lens group surrounds the transmitting-receiving lens group to support the outside of the lens barrel and is arranged in the hollow rotating body; the N laser light sources are circumferentially distributed below the receiving and transmitting lens group supporting lens cone; the N photoelectric detection units are circumferentially distributed below the receiving and transmitting lens group supporting lens cone; the first lens group and the second lens group share the optical scanning module. The optical axis of the first lens group coincides with the optical axis of the second lens group. The rotation axis of the transmission scanning unit coincides with the rotation axis of the reflection scanning unit. The laser radar is compact and simple in structure, and is provided with a coaxial nested optical path system with parallel optical paths, so that high-density space scanning is realized, and the scanning efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of laser radar based on photoelectric detection, in particular to a laser radar. Background Art

[0002] LiDAR is used to actively emit laser signals to detect and scan the environment in order to perceive the three-dimensional information of targets in the environment.

[0003] Due to its high precision and high resolution measurement advantages, LiDAR has been widely used in various fields. Especially in the fields of self-driving cars and interactive robots, LiDAR is indispensable as a core sensor.

[0004] Due to the performance limitations of the platform on which it is mounted, the LiDAR needs to be further reduced in size to ensure that the structure is as compact and simple as possible, thereby reducing the space requirements for the platform on which it is mounted. At the same time, the scanning performance must be guaranteed to achieve field of view coverage. Summary of the invention

[0005] The technical problem solved by the utility model is to provide a laser radar, which can compress the volume as much as possible and ensure a compact and simple structure.

[0006] Furthermore, a coaxial nested optical path system with parallel optical paths is used to achieve spatial high-density scanning and improve scanning efficiency.

[0007] Furthermore, the scanning points are distributed obliquely and circumferentially within the scanning field of view, so as to quickly traverse and cover the predetermined field of view.

[0008] The utility model discloses a laser radar, comprising:

[0009] An optical scanning module, comprising a transmission scanning unit and a reflection scanning unit;

[0010] A hollow rotating body, used to support and drive the optical scanning module to rotate;

[0011] The transmitting and receiving mirror group supports the mirror barrel and extends into the interior of the hollow rotating body;

[0012] A first lens group is arranged inside the supporting lens barrel of the transmitting and receiving lens group;

[0013] A second lens group is disposed around the outside of the transmitting and receiving lens group supporting lens barrel and is disposed inside the hollow rotating body;

[0014] N laser light sources are circumferentially distributed below the supporting lens barrel of the transceiver lens assembly;

[0015] N photoelectric detection units are circumferentially distributed below the supporting lens barrel of the transmitting and receiving lens group;

[0016] The first and second mirror groups share the optical scanning module, and the laser radar field of view coverage is achieved through the rotation scanning of the optical scanning module.

[0017] The optical axis of the first lens group coincides with the optical axis of the second lens group;

[0018] The rotation axis of the transmission scanning unit coincides with the rotation axis of the reflection scanning unit.

[0019] The optical axis of the first mirror group coincides with the rotation axis of the transmission scanning unit.

[0020] The transmission scanning unit is a circular wedge mirror, and the lower surface of the circular wedge mirror is not perpendicular to the rotation axis of the circular wedge mirror.

[0021] The hollow rotating body further includes an inner rotating body and an outer rotating body;

[0022] The transmission scanning unit is mounted on the top of the inner rotating body, and the transmission scanning unit is driven to rotate by rotating the inner rotating body;

[0023] The reflection scanning unit is mounted on the top of the outer rotating body, and the reflection scanning unit is driven to rotate by rotating the outer rotating body.

[0024] The supporting lens barrel of the transmitting and receiving lens group extends into the upper end of the inner rotating body to be adjacent to the transmission scanning unit.

[0025] The rotation speed of the inner rotating body is lower than the rotation speed of the outer rotating body.

[0026] The inner wall and / or outer wall of the supporting lens barrel of the transmitting and receiving lens assembly is provided with grooves to eliminate stray light.

[0027] The N laser light sources are arranged corresponding to the first lens group, and the N photoelectric detection units are arranged corresponding to the second lens group; or,

[0028] The N laser light sources are arranged corresponding to the second lens group, and the N photoelectric detection units are arranged corresponding to the first lens group.

[0029] The N laser light sources correspond to the N photoelectric detection units one by one, and together form N parallel optical path transceiver pairs. The laser light source and the photoelectric detection unit forming the same parallel optical path transceiver pair have the same phase relative to the optical axis.

[0030] The laser radar of the utility model has a small size, a compact and simple structure, and a low cost. At the same time, a coaxial nested optical path system with parallel optical paths can realize high-density spatial scanning and improve scanning efficiency.

[0031] The laser radar of the utility model can realize the oblique and surrounding distribution of scanning points within the scanning field of view, and quickly traverse and cover the predetermined field of view in space. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A Shown is a schematic diagram of the optical path of the laser radar of the present utility model.

[0033] Figure 1B Shown is a schematic structural cross-sectional diagram of the laser radar of the present utility model.

[0034] Figure 1C Shown is a partial structural cross-sectional schematic diagram of the laser radar of the present invention.

[0035] Figure 2 , 3 Shown is a schematic diagram of the top view of the arrangement of the laser light source and the photoelectric detection unit of the utility model.

[0036] Figure 4-6 Shown is a schematic diagram of the optical path of the laser emission module of the present invention.

[0037] Figure 7 , 8 Shown is the scan pattern projected into the environment. DETAILED DESCRIPTION

[0038] The implementation process of the technical solution of the present utility model is described below in conjunction with specific embodiments, which is not intended to limit the present utility model.

[0039] The utility model provides a laser radar, which can compress the volume as much as possible, ensure the compact and simple structure, and reduce the cost. At the same time, a coaxial nested optical path system with parallel optical paths can realize high-density spatial scanning and improve scanning efficiency.

[0040] The laser radar of the utility model can realize the oblique and surrounding distribution of scanning points within the scanning field of view, and quickly traverse and cover the predetermined field of view in space.

[0041] like Figure 1A The figure shows the optical path schematic diagram of the laser radar of the utility model. Figure 1B The figure shows a schematic cross-sectional view of the structure of the laser radar of the utility model. The laser radar of the utility model comprises:

[0042] Hollow rotating body, optical scanning module and transceiver detection module.

[0043] The hollow rotating body is used to accommodate the transceiver detection module and support and drive the optical scanning module to rotate, so that the transceiver detection module is located above the optical scanning module and forms a transceiver light path to realize field scanning.

[0044] The optical scanning module includes a transmission scanning unit 21 and a reflection scanning unit 22 . The reflection scanning unit 22 may be a reflection mirror or a light-transmitting medium having a reflection surface.

[0045] The transceiver detection module includes a transceiver lens group supporting lens barrel 30 , a first lens group 31 , a second lens group 32 , a laser light source 33 and a photoelectric detection unit 34 .

[0046] like Figure 2 , 3 Shown is a schematic diagram of the top view of the arrangement of the laser light source and the photoelectric detection unit of the utility model.

[0047] The utility model has N laser light sources 33 and N photoelectric detection units 34. The N laser light sources 33 are distributed in a circle around the axis 0, and can be further distributed in a centrally symmetrical or uniform distribution around the axis 0. The N photoelectric detection units 34 are distributed in a circle around the axis 0, and can be further distributed in a centrally symmetrical or uniform distribution around the axis 0 (e.g. Figure 3 as shown), evenly distributed.

[0048] The number of laser light sources 33 and photoelectric detection units 34 is the same, preferably 4, 8, 16 or 32. The positions of N laser light sources 33 and N photoelectric detection units 34 correspond to each other to form a transceiver pair, that is, the same transceiver pair (such as Figure 3 The laser light source 33 in FIG. 330 is in the same phase with the photodetection unit 34 relative to the axis O. The laser light source 33 is disposed at the periphery of the photodetection unit 34. In another embodiment, the positions of the photodetection unit 34 and the laser light source 33 can be swapped, and the photodetection unit 34 can also be disposed at the periphery of the laser light source 33.

[0049] The transceiver mirror assembly support barrel 30 is used as a support member to accommodate and carry the transceiver mirror assembly, which includes a first lens group and a second lens group. The transceiver mirror assembly support barrel 30 is a hollow cylinder, the first lens group 31 is arranged inside the transceiver mirror assembly support barrel 30, and the second lens group 32 is arranged around the outside of the transceiver mirror assembly support barrel 30.

[0050] When the laser light source 33 is arranged on the periphery of the photoelectric detection unit 34, the first mirror group 31 corresponds to the photoelectric detection unit 34 to form a light signal receiving optical path, and the second mirror group 32 corresponds to the laser light source 33 to form a laser emission optical path; when the photoelectric detection unit 34 is arranged on the periphery of the laser light source 33, the first mirror group 31 corresponds to the laser light source 33 to form a laser emission optical path, and the second mirror group 32 corresponds to the photoelectric detection unit 34 to form a light signal receiving optical path.

[0051] by Figure 1A , 1BFor example, N laser light sources 33 are distributed below the transceiver lens group support lens barrel 30, corresponding to the second lens group 32. The laser beam projected by the laser light source 33 is collimated and focused through the laser emission optical path of the second lens group 32. The laser emission optical path is used to shape the optical path of the N laser beams emitted by the N laser light sources. The shaped laser beams enter the environment through the transmission scanning unit 21 and the reflection scanning unit 22. The N laser light sources are located on the focal plane of the laser emission optical path of the second lens group 32.

[0052] The second lens group 32 at least includes a first optical lens 321 and a second optical lens 322. The first optical lens 321 and the second optical lens 322 are annular and are sleeved on the periphery of the transceiver lens group support lens barrel 30, and are correspondingly arranged above the laser light source 33.

[0053] The echo laser beam returned from the environment is guided to the photoelectric detection unit 34 via the optical signal receiving optical path of the first mirror group 31, and the N photoelectric detection units 34 are located on the focal plane of the optical signal receiving optical path of the first mirror group 31. The laser light source and the photoelectric detection unit can be located on different circuit boards, the circuit boards can be parallel to each other, and the laser light source and the photoelectric detection unit can also be located on the same circuit board.

[0054] The first lens group 31 at least includes: a first optical lens 311 and a second optical lens 312. The first optical lens 311 and the second optical lens 312 can both be circular lenses, and are disposed inside the transceiver lens group support barrel 30. N photoelectric detection units are circumferentially distributed below the transceiver lens group support barrel.

[0055] The optical axis (axis O) of the first lens group coincides with the optical axis (axis O) of the second lens group to form a coaxial nested optical path system. The laser emission optical path and the optical signal receiving optical path form parallel optical paths, so the utility model can form N parallel optical path transceiver pairs.

[0056] Based on the N parallel optical path transceiver pairs, the laser emission optical path and the optical signal receiving optical path, N groups of laser detection pointing angles with different directions but the same magnitude are formed.

[0057] Through this optical signal receiving optical path, each photoelectric detection unit can receive the echo laser beam from a specific spatial field of view angle, thus realizing the overall field of view transmission and reception closed loop of the laser radar.

[0058] The first and second mirror groups share the optical scanning module, and the laser radar field of view is covered by rotating scanning of the optical scanning module.

[0059] The transmitting and receiving lens group supporting lens barrel 30 extends into the interior of the hollow rotating body.

[0060] The hollow rotating body further includes an inner rotating body 11 and an outer rotating body 12. The inner and outer rotating bodies are driven to rotate by motor power modules 41 and 42 respectively. The bearing module 411 is arranged on the outer wall of the inner rotating body 11, and the bearing module 421 is arranged between the inner and outer rotating bodies.

[0061] The transmission scanning unit 21 is mounted on the top of the inner rotating body 11 , and the transmission scanning unit 21 is driven to rotate by rotating the inner rotating body.

[0062] The top of the outer rotating body 12 is connected to the supporting member 13 through connecting members 14 and 15. The supporting member 13 is provided with the reflection scanning unit 22. The reflection scanning unit 22 is driven to rotate by rotating the outer rotating body 12.

[0063] The rotation axis of the transmission scanning unit coincides with the rotation axis of the reflection scanning unit.

[0064] In an optimized embodiment, the optical axis of the first lens group coincides with the rotation axis of the transmission scanning unit, both being axis O.

[0065] The outer rotating body 12 is sleeved on the outer upper part of the inner rotating body 11 , so that the reflection scanning unit 22 is located above the transmission scanning unit 21 .

[0066] The transceiver mirror group supporting lens barrel 30 extends into the upper end of the inner rotating body 11, so that the transceiver mirror group supporting lens barrel 30 is as close to the transmission scanning unit as possible, with a gap but no contact, compressing the size in the height direction, covering each other in the horizontal direction, and reducing the overall volume of the laser radar.

[0067] The transmission scanning unit 21 is a circular wedge mirror. The cross section of the circular wedge mirror is a wedge shape. Figure 1A As shown, it is circular in a plane perpendicular to the optical axis O.

[0068] In an optimized embodiment, the lower surface of the circular wedge mirror is not perpendicular to the rotation axis of the circular wedge mirror, so that part of the laser beam emitted by the laser light source fails to successfully transmit the circular wedge mirror and when reflected by the lower surface of the circular wedge mirror, it is reflected to the side wall of the transceiver mirror assembly supporting lens barrel 30 instead of returning along the original path. The side wall can be coated with black light-absorbing paint, so that the part of the laser beam that becomes stray light is absorbed to avoid noise in the optical system.

[0069] The inner side wall and / or the outer side wall of the transmitting and receiving lens assembly supporting lens barrel 30 may also be provided with grooves, such as Figure 1C The outer wall of the transceiver lens group support lens barrel 30 and the inner wall of the inner rotating body 11 together form an optical channel, which limits the channel range of the laser beam corresponding to the second lens group 32 and absorbs its stray light.

[0070] like Figure 4 As shown, in one embodiment, taking 4 laser light sources as an example, the laser emission optical path focuses and projects 4 laser beams L, and the 4 laser beams L form a spatial convergence emission mode around the optical axis O, so that the 4 laser beams L are all biased towards the optical axis O for central focus. In an optimized embodiment, the angle between each laser beam L and the optical axis O (the laser detection pointing angle of the laser emission optical path) is the same, but the directions are different, and they are uniformly focused toward the center. Each laser light source guides a channel, and the direction of each laser beam L forms a channel.

[0071] Based on the N parallel optical path transceiver pairs, the laser emission optical path and the optical signal receiving optical path, N groups of laser detection pointing angles with different directions but the same magnitude are formed.

[0072] like Figure 1A , 5 As shown, the laser light source is outside, the photoelectric detection unit is inside, and the focal length of the second lens group is ft( Figure 5 O1O3) is greater than the focal length of the first lens group fr( Figure 5 O1O2), the radius of the circle where the N laser light sources are located is Rt( Figure 5 O1F) is greater than the radius Rr ( Figure 5 O1E) and meet the following requirements:

[0073] tan(θt)=tan(θr)=Rt / ft=Rr / fr, ft>fr, Rt>Rr;

[0074] θt is the laser detection pointing angle of the laser emission optical path in the parallel optical path, and θr is the laser detection pointing angle of the optical signal receiving optical path in the parallel optical path.

[0075] In another embodiment, the laser light source is inside and the photoelectric detection unit is outside. Figure 6 As shown, the focal length of the first lens group is ft( Figure 6 O1O2) is smaller than the focal length fr of the second lens group ( Figure 6 O1O3), the radius of the circle where the N laser light sources are located is Rt( Figure 6 O1E) is smaller than the radius Rr ( Figure 6 O1F), meet the following requirements:

[0076] tan(θt)=tan(θr)=Rt / ft=Rr / fr, ft <fr,Rt<Rr。

[0077] The transmitting and receiving optical paths are parallel to each other, the light beams corresponding to the same transmitting and receiving pair are parallel to each other, O2E is parallel to O3F, O2E is inside O3F, and the light beams of different transmitting and receiving pairs are distributed around the optical axis O.

[0078] The circular wedge mirror rotates 360 degrees around the axis, driving the laser beam projected by the laser light source to rotate periodically. The laser beam is reflected by the rotating reflector 22 and emitted into the environment, forming a scanning detection of the environment and also forming a scanning pattern. The rotating reflector 22 rotates 360 degrees around the axis, thereby realizing 360-degree spatial scanning and image rotation scanning of the laser beam.

[0079] The rotating reflector 22 has a reflective surface 221. The N laser beams are projected onto the reflective surface 221 after passing through the circular wedge mirror 21. A , L C After being emitted by the reflective surface 221, an outgoing light beam L1 is formed. A 、L1 C , the echo beams are R1 A 、R1 C , L1 A Parallel R1 A , L1 C Parallel R1 C , thus forming a parallel field of view for transmission and reception. Based on the angle between each laser beam and the optical axis, the symmetrical laser beam (for example, L A , L C ) have a larger angle space between them, and the parallel field of view for transmitting and receiving can expand the light receiving area, improve the efficiency of the optical system, and enhance the measurement accuracy. At the same time, the parallel field of view, in conjunction with the coaxial nested structure and the different directions of the laser beams, can increase the spacing between the multiple channels led by multiple laser light sources and enable the multiple channels on one side of the emitting surface 221 to form a larger angle with each other. The scanning points are then distributed in an inclined and surrounding manner within the scanning field of view, and the predetermined field of view is quickly traversed and covered in space.

[0080] In a preferred embodiment, the rotation speed of the circular wedge mirror 21 is lower than the rotation speed of the rotating reflector 22 .

[0081] The rotation of the optical scanning module drives the laser beams projected by N laser light sources to scan, and finally forms N groups of laser transceiver detection scanning trajectories in space. The spatial distribution of the N groups of laser transceiver detection scanning trajectories corresponds to the angular distribution of the N laser light sources on the laser focal plane. With the help of the optical scanning module, the laser radar forms a parallel field of view for transmission and reception.

[0082] like Figure 7 , 8 As shown in the figure, the final scanning pattern projected in the environment, the laser beam of each laser light source can generate a set of laser transceiver detection scanning tracks S (the four channels are S A , S B , S C , S D), each group of laser transceiver detection scanning trajectories is evenly distributed around a central axis, and the spatial distribution of the N groups of laser transceiver detection scanning trajectories corresponds to the angular distribution of the N laser light sources on the laser focal plane. Figure 7 This is a three-dimensional picture of the scanning trajectory of 4 sets of laser transceiver detection. Figure 8 The top view of the 4 sets of laser transceiver detection scanning trajectories. The 4 sets of laser transceiver detection scanning trajectories realize the intersection of scanning line space grid and achieve high-density spatial scanning.

[0083] Each set of laser transceiver detection scanning tracks S are distributed in an inclined and surrounding manner, so as to quickly cover the vertical and horizontal fields of view in a single circle scan and quickly traverse the space.

[0084] In addition, the circular wedge mirror 31 and the rotating reflector 32 have different rotation speeds, and the rotation speed of the inner rotating body is lower than that of the outer rotating body, so that the scanning points can have a greater difference.

[0085] 0.05<180<0.072

[0086] Δv

[0087] Δv is the difference between the angular velocity of the outer rotating body and the angular velocity of the inner rotating body.

[0088] Through the rotation speed setting, adjacent scanning circles can be slightly staggered from each other under the premise that the scanning trajectory gives priority to vertical coverage, that is, the scanning grid is further subdivided to improve the resolution.

[0089] The laser radar of the utility model has a small size, a compact and simple structure, and a low cost. At the same time, a coaxial nested optical path system with parallel optical paths can realize high-density spatial scanning and improve scanning efficiency.

[0090] The laser radar of the utility model can realize the oblique and surrounding distribution of scanning points within the scanning field of view, and quickly traverse and cover the predetermined field of view in space.

[0091] The above embodiments are only used to describe the technical solution of the present invention and are not to be regarded as limiting the present invention.

Claims

1. A laser radar, characterized in that: include: An optical scanning module, comprising a transmission scanning unit and a reflection scanning unit; A hollow rotating body, used to support and drive the optical scanning module to rotate; The transmitting and receiving mirror group supports the mirror barrel and extends into the interior of the hollow rotating body; A first lens group is arranged inside the supporting lens barrel of the transmitting and receiving lens group; A second lens group is disposed around the outside of the transmitting and receiving lens group supporting lens barrel and is disposed inside the hollow rotating body; N laser light sources are circumferentially distributed below the supporting lens barrel of the transceiver lens assembly; N photoelectric detection units are circumferentially distributed below the supporting lens barrel of the transmitting and receiving lens group; The first and second mirror groups share the optical scanning module, and the laser radar field of view coverage is achieved through the rotation scanning of the optical scanning module.

2. The laser radar according to claim 1, characterized in that The optical axis of the first lens group coincides with the optical axis of the second lens group; The rotation axis of the transmission scanning unit coincides with the rotation axis of the reflection scanning unit.

3. The laser radar according to claim 2, characterized in that The optical axis of the first mirror group coincides with the rotation axis of the transmission scanning unit.

4. The laser radar according to claim 1, characterized in that The transmission scanning unit is a circular wedge mirror, and the lower surface of the circular wedge mirror is not perpendicular to the rotation axis of the circular wedge mirror.

5. The laser radar according to claim 1, characterized in that: The hollow rotating body further includes an inner rotating body and an outer rotating body; The transmission scanning unit is mounted on the top of the inner rotating body, and the transmission scanning unit is driven to rotate by rotating the inner rotating body; The reflection scanning unit is mounted on the top of the outer rotating body, and the reflection scanning unit is driven to rotate by rotating the outer rotating body.

6. The laser radar according to claim 5, characterized in that The supporting lens barrel of the transmitting and receiving lens group extends into the upper end of the inner rotating body to be adjacent to the transmission scanning unit.

7. The laser radar according to claim 5, characterized in that The rotation speed of the inner rotating body is lower than the rotation speed of the outer rotating body.

8. The laser radar according to claim 1, characterized in that: The inner wall and / or outer wall of the supporting lens barrel of the transmitting and receiving lens assembly is provided with grooves to eliminate stray light.

9. The laser radar according to claim 1, characterized in that: The N laser light sources are arranged corresponding to the first lens group, and the N photoelectric detection units are arranged corresponding to the second lens group; or, The N laser light sources are arranged corresponding to the second lens group, and the N photoelectric detection units are arranged corresponding to the first lens group.

10. The laser radar according to claim 2, characterized in that: The N laser light sources correspond to the N photoelectric detection units one by one, and together form N parallel optical path transceiver pairs. The laser light sources and the photoelectric detection units forming the same parallel optical path transceiver pair have the same phase relative to the optical axis of the first mirror group.

Images