Scanning device for laser radar

Abstract

The utility model discloses a scanning device for a laser radar, and the device comprises a supporting ring which is provided with a cavity; the first scanning assembly is located in the cavity, the first scanning assembly comprises a first optical element, a first driving device and a first rotating support, and the first rotating support is driven by the first driving device to drive the first optical element to rotate around a rotating shaft; the second scanning assembly is located in the cavity, the second scanning assembly comprises a second optical element, a second driving device and a second rotating support, and the second rotating support is driven by the second driving device to drive the second optical element to rotate relative to the supporting ring; a part of the first rotating support extends into the inner space of the second rotating support, and a ventilation gap exists between the part of the first rotating support and the second rotating support. The combined driving device is used for realizing combined driving of laser scanning with multiple optical elements. The structure of the internal space of the scanning device is reasonably arranged, so that the volume is compressed.

Description

Technical Field

[0001] The utility model relates to the technical field of lidar based on photoelectric detection, and particularly relates to a scanning device for a lidar. Background Art

[0002] The lidar is used for three-dimensional scanning and recognition of target objects in the environment. Due to its advantages of long measurement range, high precision, strong directivity, high resolution, anti-interference, and the ability to obtain three-dimensional data of target objects, it has been widely used in various fields, such as topographic mapping, engineering exploration, power inspection, vegetation monitoring, intelligent navigation, and many other fields.

[0003] The scanning device of the lidar usually has a rotating optical element, which rotates to expand the scanning range. How to achieve the combined drive of multi-mirror group scanning and how to reasonably utilize the internal structure of the scanning device to compress the volume are the common pursuits of those skilled in the art. Summary of the Invention

[0004] The technical problem solved by the utility model is to provide a scanning device for a lidar, which is used to achieve the combined drive of laser scanning with multiple optical elements.

[0005] Furthermore, the internal space of the scanning device is reasonably arranged in terms of structure to compress the volume.

[0006] Furthermore, a position for the lens barrel is reserved in the internal space of the scanning device to achieve a specific scanning mode of the utility model.

[0007] The utility model discloses a scanning device for a lidar, which comprises:

[0008] A support ring, having a cavity;

[0009] A first scanning assembly, located in the cavity. The first scanning assembly includes a first optical element, a first driving device, and a first rotating bracket. The first rotating bracket drives the first optical element to rotate around the rotation axis under the drive of the first driving device;

[0010] A second scanning assembly, located in the cavity. The second scanning assembly includes a second optical element, a second driving device, and a second rotating bracket. The second rotating bracket drives the second optical element to rotate relative to the support ring under the drive of the second driving device;

[0011] A part of the first rotating bracket extends into the internal space of the second rotating bracket, and there is a ventilation gap between this part of the first rotating bracket and the second rotating bracket.

[0012] One side of the first driving device abuts against the support ring, and the other side abuts against the first rotating bracket;

[0013] One side of the second driving device abuts against the support ring, and the other side abuts against the second rotating bracket.

[0014] The first driving device includes a first bearing and a first motor device. The first bearing is located between the support ring and the first rotating bracket, and the first motor device is located between the support ring and the first rotating bracket.

[0015] The second driving device includes a second bearing and a second motor device. The second bearing is located between the support ring and the second rotating bracket, and the second motor device is located between the support ring and the second rotating bracket.

[0016] The first optical element extends into the internal space of the second rotating bracket.

[0017] The first rotating bracket includes a rotating support frame and an optical element carrier. The rotating support frame is used to accommodate the optical barrel of the lidar, and the optical element carrier is used to carry the first optical element. The rotating support frame and the optical element carrier are arranged along the axial direction of the rotating shaft.

[0018] The cross-section of the rotating support frame has a first abutting area, a second abutting area, and a third abutting area connected in sequence. The first abutting area abuts against the optical element carrier, the second abutting area abuts against the first bearing, and the third abutting area abuts against the first motor device.

[0019] The cross-section of the rotating support frame is stepped, and the first, second, and third abutting areas are respectively located on the first, second, and third steps.

[0020] In the space sandwiched between the support ring and the first and second rotating brackets, the first motor device, the first bearing, the second bearing, and the second motor device are arranged in sequence along the axial direction of the rotating shaft.

[0021] The second optical element includes a support platform, a weight unit, and a reflective dielectric mirror. The support platform is mounted on the second rotating bracket.

[0022] The support platform has an abutting portion and a top portion. The abutting portion abuts against the inner wall of the second rotating bracket, and the top portion is located at the upper edge of the second rotating bracket.

[0023] The top surface of the support platform has a first area. The first area is adjacent to the reflective dielectric mirror and is located in the light-emitting area of the reflective dielectric mirror. The first area is provided with a plurality of grooves.

[0024] The first optical element is a circular wedge mirror. The upper and lower surfaces of the circular wedge mirror are not perpendicular to the rotating shaft. The inclination angle of the lower surface of the circular wedge mirror is greater than or equal to 2° and less than or equal to 4°.

[0025] The present utility model also discloses a lidar, including the scanning device described above.

[0026] The above technical solution of the present utility model is used to achieve a combined drive for laser scanning with multiple optical elements. At the same time, the internal space of the scanning device is reasonably arranged in terms of structure to compress the volume. In addition, through reasonable selection and arrangement of structural members, the rotation is more stable, and the distribution of the scanned laser points is more uniform. At the same time, stray light can be absorbed to ensure the accuracy of the received signals. The present utility model reserves the position of the lens barrel in the internal space of the scanning device to achieve the specific scanning mode of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The schematic diagram of the principle of the lidar of the present utility model is shown.

[0028] Figure 2 The schematic cross-sectional view of the structure of the scanning device for the lidar of the present utility model is shown.

[0029] Figure 3 The overall schematic diagram of the support ring equipped with a driving device and a rotating bracket is shown.

[0030] Figure 4 The schematic cross-sectional view of the structure of the first scanning component is shown.

[0031] Figure 5 The partial schematic cross-sectional view of the structure of the second scanning component is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The implementation process of the technical solution of the present utility model is described below in conjunction with specific embodiments, which shall not be construed as a limitation to the present utility model.

[0033] The present utility model provides a scanning device and a lidar for a lidar, as Figure 1 The schematic diagram of the principle of the lidar of the present utility model is shown.

[0034] The scanning device 100 is arranged in the lidar. The scanning device 100 includes a first scanning component and a second scanning component. The first scanning component includes a first optical element 31, and the first optical element can be a circular wedge mirror. The second scanning component includes a second optical element 32, and the second optical element can be a rotating mirror. The circular wedge mirror is driven to rotate around the axis O, and the rotating mirror is driven to rotate around the axis O, and the two rotate in the same direction.

[0035] The lidar has N laser light sources 1 for forming N laser beams, a laser emission optical path 41, N photoelectric detection units 2, and an optical signal reception optical path 42. The laser emission optical path 41 is annular and is sleeved around the periphery of the optical signal reception optical path 42. The optical signal reception optical path 42 is circular.

[0036] The N laser light sources 1 are located on the laser emission optical path focal plane of the laser emission optical path 41, and are circumferentially distributed around the axis O. Further, they are evenly distributed or centrosymmetrically distributed with the axis O as the central axis. The distances of the N laser light sources 1 from the axis O are the same, and the N laser light sources are arranged in sequence with the same angular difference relative to the axis O.

[0037] The N photoelectric detection units 2 are located on the optical signal reception optical path focal plane of the optical signal reception optical path 42. Corresponding to the N laser light sources, the N photoelectric detection units are circumferentially distributed on the optical signal reception optical path focal plane. Further, they are evenly distributed or centrosymmetrically distributed with the central axis. The distances of the N photoelectric detection units 2 from the optical axis are the same. In an optimized embodiment, the N photoelectric detection units 2 are arranged in sequence with the same angular difference relative to the axis O. The photoelectric detection unit 2 receives the echo laser beam of the laser beam projected by the laser light source 1, and the N laser light sources and the N photoelectric detection units are in one-to-one correspondence. The laser light source and the photoelectric detection unit with a corresponding relationship form a transceiver pair, and the laser light source and the photoelectric detection unit forming the same transceiver pair have the same phase relative to the axis O of the laser emission optical path.

[0038] The laser beam emitted by the laser light source 1 is collimated by the laser emission optical path 41 and then enters the first optical element. The rotating first optical element refracts it to continuously adjust its propagation direction, and then passes through the rotating second optical element and is projected into the external environment of the lidar to achieve 360-degree full-field scanning. Each collimated laser beam (L A 、L B 、L C 、L D ) has the same angle size but different directions with respect to the optical axis O. The first and second optical elements correspond to each other in the axial direction of the axis O.

[0039] Through the above scanning device, it is possible to achieve that the scanning points are inclined and circumferentially distributed and diffused within the scanning field of view, and quickly scan and traverse and cover the points in the predetermined field of view.

[0040] As Figure 2 shown is the structural cross-sectional schematic diagram of the scanning device. As Figure 3 shown is the structural schematic diagram of the support ring. As Figure 4 shown is the structural cross-sectional schematic diagram of the first scanning component.

[0041] The scanning device 100 further includes a support ring, which is a hollow cylindrical structure with a cavity inside. The support ring can be integrally formed or composed of two support sub-rings 101 and 102 connected to each other. The connection method can include bonding, snapping, etc., and is not limited thereto.

[0042] A first scanning assembly, located inside the cavity. The first scanning assembly includes a first rotating bracket 11, a first driving device, and a first optical element 31. The first rotating bracket drives the first optical element to rotate around the rotation axis O under the drive of the first driving device.

[0043] A second scanning assembly, located inside the cavity. The second scanning assembly includes a second rotating bracket 21, a second driving device, and a second optical element 32. The second rotating bracket drives the second optical element to rotate relative to the support ring under the drive of the second driving device.

[0044] Figure 3 Shown is a schematic diagram of the overall support ring assembled with a driving device and a rotating bracket.

[0045] The first scanning assembly is closer to the laser emission optical path 41 and the optical signal receiving optical path 42 than the second scanning assembly.

[0046] One side of the first driving device abuts against the support ring, and the other side abuts against the first rotating bracket.

[0047] Specifically, the first driving device includes a first bearing 12 and a first motor device 13. The first rotating bracket 11 includes a rotating support frame 112 and an optical element carrier 111, which are connected to each other.

[0048] The first bearing 12 is located between the support ring 102 and the first rotating bracket 11, and the first motor device 13 is located between the support ring 102 and the first rotating bracket 11.

[0049] The optical signal receiving optical path 42 is fixed inside the optical lens barrel 40, and the laser emission optical path 41 is fixed on the outer wall of the optical lens barrel. The first rotating bracket is a hollow cylinder, and a quasi-direct light passage is formed inside it. The optical lens barrel extends into the inside of the first rotating bracket 11 but does not contact the first rotating bracket.

[0050] The first rotating bracket includes a rotating support frame 112 and an optical element carrier 111. The rotating support frame and the optical element carrier are arranged axially along the axis O.

[0051] The optical element carrier 111 is used to carry the first optical element 31. The first optical element 31 is located above the optical lens barrel and receives N collimated laser beams. The rotation axis O of the first optical element coincides with the optical axis of the optical signal receiving optical path 42 and the optical axis of the laser emission optical path 41. The first optical element 31 faces the laser emission optical path 41 and can receive all the beams emitted from the laser emission optical path 41.

[0052] The first optical element is a circular wedge mirror, and the upper and lower surfaces of the circular wedge mirror are not perpendicular to the axis O. The inclination angle of the lower surface of the circular wedge mirror is greater than or equal to 2° and less than or equal to 4°. The wedge angle of the circular wedge mirror is greater than or equal to 3° and less than or equal to 14°.

[0053] The rotation support frame and the optical element carrier are stably connected to each other. The connection methods can include snap-fitting, bonding, etc., and are not limited thereto.

[0054] The cross-section of the rotation support frame has a first abutting area, a second abutting area, and a third abutting area connected in sequence. The first abutting area abuts the optical element carrier 111, the second abutting area abuts the first bearing 12, and the third abutting area abuts the first motor device 13, so that the first bearing and the first motor device are at different axial heights (along the axis O), in order to compress the radial radius of the scanning device. In one embodiment, the cross-section of the rotation support frame is stepped, and the first, second, and third abutting areas are respectively located on the first, second, and third steps. The third abutting area can be the first magnetic yoke 1121.

[0055] A part of the first rotating bracket extends into the internal space of the second rotating bracket, that is, a part of the first rotating bracket is arranged in parallel with the second rotating bracket in the radial direction (along the axis O). There is a ventilation gap between the part of the first rotating bracket and the second rotating bracket, so that the first rotating bracket and the second rotating bracket do not interfere with each other when rotating respectively, and form air ducts for heat dissipation respectively, and the two rotating brackets are partially overlapped in layout to save space and compress the volume.

[0056] Specifically, the first optical element extends into the internal space of the second rotating bracket to compress the optical path as much as possible and avoid waste of the energy of the laser signal.

[0057] The second optical element is a reflector or a reflective dielectric mirror or other mirror bodies that can achieve reflection.

[0058] One side of the second driving device abuts against the support ring, and the other side abuts against the second rotating bracket.

[0059] Specifically, the second driving device includes a second bearing 22 and a second motor device 23. The second bearing 22 is located between the support sub-ring 101 and the second rotating bracket 21, and the second motor device is located between the support sub-ring 101 and the second rotating bracket 21.

[0060] The second optical element 32 includes a support platform 321, a reflective dielectric mirror 322, and a counterweight unit 323. The reflective dielectric mirror has a first surface A for reflection, and the counterweight unit is adjacent to the first surface. The support platform surrounds and bears the counterweight unit and the reflective dielectric mirror, and the support platform is mounted on the second rotating bracket 21. The support platform is stably connected to the counterweight unit and the reflective dielectric mirror, and the support platform rotates with the second rotating bracket 21.

[0061] The support platform 321 has a abutting portion and a top abutting portion. The abutting portion abuts against the inner wall of the second rotating bracket, that is, the other side of the second magnetic yoke 211, and the top abutting portion is located at the upper edge of the second rotating bracket, that is, the upper edge of the second magnetic yoke 211. By arranging the rotor and the support platform carrying the reflective dielectric mirror on both sides of the second rotating bracket, and although the abutting portion of the rotor and the support platform is separated by the second rotating bracket but the positions are corresponding, the rotational power is directly transmitted to the second rotating bracket and the support platform, making the rotation more stable.

[0062] See Figure 5 , on the top surface of the support platform 321, there is a first area. The first area is adjacent to the reflective dielectric mirror 322 and is located in the light output area of the reflective dielectric mirror. The laser beams entering and leaving the reflective dielectric mirror 322 all pass through the first area 3211. The first area is provided with a plurality of grooves, and the grooves are used to reflect and absorb the stray light entering and leaving the reflective dielectric mirror 322, so as to reduce the stray light noise and ensure the accuracy of the received signal.

[0063] In the axial direction, the first motor device 13, the first bearing 12, the second bearing 22, and the second motor device 23 are arranged in sequence along the axial direction. Since in the channel sandwiched by the support ring and the two rotating brackets, the two motor devices are respectively located at the head and tail of the channel, and the two bearings are relatively enclosed inside the channel, it is difficult for the lubricating grease added to the bearings to leak out of the channel, avoiding contamination of the optical elements.

[0064] The above technical solution of the present utility model is used to realize the combined drive with multi-optical element laser scanning. At the same time, the internal space of the scanning device is reasonably arranged in terms of structure to compress the volume. In addition, by reasonably selecting and arranging the structural members, the rotation is more stable and the distribution of the scanning laser points is more uniform. The present utility model reserves the position of the lens barrel in the internal space of the scanning device to realize the specific scanning mode of the present utility model.

[0065] The above embodiments are only used to describe the technical solutions of the present utility model and are not regarded as limitations on the present utility model.

Claims

1. A scanning device for lidar, characterized in that, The scanning device includes: A support ring having a cavity; A first scanning assembly located within the cavity, the first scanning assembly including a first optical element, a first driving device, and a first rotating bracket, and the first rotating bracket drives the first optical element to rotate around a rotation axis under the drive of the first driving device; A second scanning assembly located within the cavity, the second scanning assembly including a second optical element, a second driving device, and a second rotating bracket, and the second rotating bracket drives the second optical element to rotate relative to the support ring under the drive of the second driving device; A part of the first rotating bracket extends into the internal space of the second rotating bracket, and there is a ventilation gap between this part of the first rotating bracket and the second rotating bracket.

2. The scanning device for lidar according to claim 1, characterized in that, One side of the first driving device abuts against the support ring, and the other side abuts against the first rotating bracket; One side of the second driving device abuts against the support ring, and the other side abuts against the second rotating bracket.

3. The scanning device for lidar according to claim 2, wherein The first driving device includes a first bearing and a first motor device, the first bearing is located between the support ring and the first rotating bracket, and the first motor device is located between the support ring and the first rotating bracket; The second driving device includes a second bearing and a second motor device, the second bearing is located between the support ring and the second rotating bracket, and the second motor device is located between the support ring and the second rotating bracket.

4. The scanning device for lidar according to claim 1, characterized in that, The first optical element extends into the internal space of the second rotating bracket.

5. The scanning device for lidar according to claim 1 or 2, characterized in that, The first rotating bracket includes a rotating support frame and an optical element carrier frame. The rotating support frame is used to accommodate the optical barrel of the lidar, and the optical element carrier frame is used to carry the first optical element. The rotating support frame and the optical element carrier frame are arranged axially along the rotation axis.

6. The scanning device for lidar according to claim 3, characterized in that, The first rotating bracket includes a rotating support frame and an optical element carrier frame. The rotating support frame is used to accommodate the optical barrel of the lidar, and the optical element carrier frame is used to carry the first optical element. The rotating support frame and the optical element carrier frame are arranged axially along the rotation axis.

7. The scanning device for lidar according to claim 6, wherein, The cross-section of the rotating support frame has a first abutting area, a second abutting area, and a third abutting area connected in sequence. The first abutting area abuts against the optical element carrier frame, the second abutting area abuts against the first bearing, and the third abutting area abuts against the first motor device.

8. The scanning device for lidar according to claim 7, characterized in that, The cross-section of the rotating support frame is stepped, and the first, second, and third abutting areas are respectively located on the first, second, and third steps.

9. The scanning device for lidar according to claim 3, characterized in that, In the space sandwiched between the support ring and the first and second rotating brackets, the first motor device, the first bearing, the second bearing, and the second motor device are arranged axially in sequence along the rotation axis.

10. The scanning device for lidar according to claim 1, characterized in that, The second optical element includes a support platform, a counterweight unit, and a reflective medium mirror, and the support platform is mounted on the second rotating bracket; The support platform has an abutting portion and a top abutting portion. The abutting portion abuts against the inner wall of the second rotating bracket, and the top abutting portion is located at the upper edge of the second rotating bracket.

11. The scanning device for lidar according to claim 10, characterized in that, The top surface of the support platform has a first area, the first area is adjacent to the reflective medium mirror and is located in the light-emitting area of the reflective medium mirror, and a plurality of grooves are provided in the first area.

12. The scanning device for lidar according to claim 1, wherein, The first optical element is a circular wedge mirror. Neither the upper surface nor the lower surface of the circular wedge mirror is perpendicular to the rotation axis. The inclination angle of the lower surface of the circular wedge mirror is greater than or equal to 2° and less than or equal to 4°.

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