A lidar and its receiver blind spot compensation mechanism

Abstract

This invention provides a lidar and its receiving blind spot compensation mechanism. The receiving blind spot compensation mechanism includes a concave mirror placed outside the L-shaped light-transmitting tube of the lidar. The emitted beam of the lidar passes through the lower port of the L-shaped light-transmitting tube, is reflected at the corner inside the L-shaped light-transmitting tube, and then exits from the upper port of the L-shaped light-transmitting tube to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light-transmitting tube is reflected by the concave mirror and enters the receiving mirror. This invention achieves compensation for the blind spot of the lidar, improving the detection efficiency of nearby targets.

Description

Technical Field

[0001] This utility model relates to the field of lidar technology, specifically to a lidar and its receiving blind spot compensation mechanism. Background Technology

[0002] Coaxial LiDAR systems are characterized by their compact structure, high integration, small scanning blind zone, and high stability, making them adaptable to complex and ever-changing environments and scenarios, and their applications are becoming increasingly widespread. To constrain the transmission path of the emitted beam and shield it from stray light interference with echo laser detection, a light guide is typically placed in the emitted optical path of the LiDAR, confining the emitted beam within the guide structure. While the light guide suppresses invalid echo light, it also introduces the problem of physical obstruction of the received beam. Because the surfaces of most real-world targets are rough, although the emitted beams of the LiDAR are parallel, when the laser beam strikes the rough surface of the target, the reflected light diffuses in different directions. When the target is very close to the LiDAR, the angle between the propagation direction of the light diffusely reflected from different points on the target surface and the receiving optical axis can be very wide, containing a large number of large-angle reflected rays. The wide-angle diffuse reflection light generated by the target object at close range is blocked by the light tube, resulting in a large amount of effective echo light failing to reach the receiving device, thus forming a close-range detection blind zone for lidar (especially lidar with coaxial transceiver). Utility Model Content

[0003] The purpose of this invention is to provide a lidar and its receiving blind spot compensation mechanism to improve the echo detection intensity of targets at close range and reduce the close-range detection blind spot of the lidar.

[0004] To solve the above-mentioned technical problems, this utility model provides a receiving blind spot compensation mechanism for lidar, including a concave mirror disposed outside the L-shaped light transmission tube of the lidar; The output beam of the lidar passes through the lower port of the lidar's L-shaped light tube, and after being reflected at the corner inside the L-shaped light tube, it is emitted from the upper port of the L-shaped light tube to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light tube is reflected by the concave mirror and then enters the receiving mirror.

[0005] According to the above scheme, the concave mirror is a spherical concave mirror.

[0006] According to the above scheme, the concave mirror is a parabolic concave mirror.

[0007] According to the above scheme, the projection of the concave mirror onto the receiving mirror of the lidar is within the receiving range of the receiving mirror.

[0008] According to the above scheme, the concave mirror is set at the outer corner of the L-shaped light tube of the lidar.

[0009] This utility model also provides a lidar, including a housing, an optical cover, a mirror rotation assembly, a laser transceiver assembly, and a concave mirror; The bottom of the optical cover is connected to the top of the housing, and the reflective rotating component and the laser transceiver component are distributed vertically within the cavity formed by the optical cover and the housing; The mirror rotation assembly includes a motor, a mirror, and an L-shaped light-transmitting tube; the motor is fixed inside the top of the optical cover, the mirror is connected to the output shaft of the motor, and the L-shaped light-transmitting tube is connected to the mirror surface of the mirror; The laser transceiver assembly includes a receiver mount, a photodetector, a receiver, a collimating tube, a collimating lens, and a laser transmitter. The receiver mount is located at the bottom of the housing, the photodetector is located on the bottom surface of the receiver mount, the receiver is connected to the top of the receiver mount, the collimating tube passes through the central axis of the receiver, and the collimating lens and the laser transmitter are located at the top and bottom of the collimating tube, respectively. The laser beam emitted by the laser emitter is collimated into a parallel beam by a collimating lens and then enters the lower port of the L-shaped light tube. After being reflected by a mirror in the L-shaped light tube, it exits from the upper port of the L-shaped light tube to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light tube is reflected by a concave mirror and enters the receiving mirror. The diffuse reflection beam that enters the receiving mirror is focused by the receiving mirror onto the photodetector.

[0010] According to the above scheme, the concave mirror is a spherical concave mirror.

[0011] According to the above scheme, the concave mirror is a parabolic concave mirror.

[0012] According to the above scheme, the projection of the concave mirror in the direction of the receiving mirror is within the receiving range of the receiving mirror.

[0013] According to the above scheme, the concave mirror is placed at the outer corner of the L-shaped light-transmitting tube.

[0014] Beneficial effects This invention utilizes a concave mirror to ensure that a portion of the effective echo light outside the light-transmitting tube in the diffuse reflection beam generated by a near-range target is reflected by the concave mirror and enters the receiving mirror. This significantly increases the total amount of echo light reaching the receiving mirror, enhancing the detection intensity of echo signals from near-range targets. Because the concave mirror itself has focusing properties, compared to other reflective elements such as plane mirrors, it can more efficiently shape and converge the divergent diffuse reflection light to the receiving mirror, further improving the utilization rate of the echo light, enhancing the blind spot compensation effect, and ensuring the stability and reliability of near-range target detection. Compared to lidar systems without this blind spot compensation mechanism, this invention does not require altering the constraint of the L-shaped light-transmitting tube on the emitted beam and its stray light shielding function. While retaining the advantages of the original structure, it achieves blind spot compensation by adding a concave mirror. The structure is simple and highly compatible, effectively balancing the obstruction problem of the light-transmitting tube with the echo detection efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a lidar structure according to an embodiment of the present invention.

[0016] In the diagram: 1-casing, 2-optical cover, 3-motor, 4-reflector, 5-light tube, 6-concave mirror, 7-aperture, 8-receiving mirror mount, 9-receiving mirror, 10-photodetector, 11-collimating lens tube, 12-collimating mirror, 13-laser emitter. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0018] See Figure 1 This embodiment discloses a blind spot compensation mechanism for lidar, including a concave mirror 6; The output beam of the lidar passes through the lower port of the L-shaped light tube 5 of the lidar, and after being reflected at the corner inside the L-shaped light tube 5, it is emitted from the upper port of the L-shaped light tube 5 to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light tube is reflected by the concave mirror 6 and enters the receiving mirror 9.

[0019] Furthermore, the concave mirror 6 is a spherical concave mirror 6.

[0020] Furthermore, the concave mirror 6 is a parabolic concave mirror 6.

[0021] Furthermore, the projection of the concave mirror 6 onto the receiving mirror 9 of the lidar is within the receiving range of the receiving mirror 9.

[0022] Furthermore, the concave mirror 6 is positioned at the outer corner of the L-shaped light-transmitting tube 5 of the lidar.

[0023] See Figure 1 This embodiment also discloses a lidar, including a housing 1, an optical cover 2, a rotating reflector 4, a laser transceiver assembly, and a concave mirror 6; The bottom of the optical cover 2 is connected to the top of the housing 1, and the reflective rotating component and the laser transceiver component are distributed vertically within the cavity formed by the optical cover 2 and the housing 1. The rotating assembly of the reflector 4 includes a motor 3, a reflector 4, and an L-shaped light-transmitting tube 5; the motor 3 is fixed inside the top of the optical cover 2, the reflector 4 is connected to the output shaft of the motor 3, and the L-shaped light-transmitting tube 5 is connected to the mirror surface of the reflector 4. The laser transceiver assembly includes a receiver mount 8, a photodetector 10, a receiver 9, a collimating tube 11, a collimating lens 12, and a laser emitter 13. The receiver mount 8 is located at the bottom of the housing 1, the photodetector 10 is located on the bottom surface of the receiver mount 8, the receiver 9 is connected to the top of the receiver mount 8, the collimating tube 11 passes through the central axis of the receiver 9, and the collimating lens 12 and the laser emitter 13 are respectively located at the top and bottom of the collimating tube 11. The laser beam emitted by the laser emitter 13 is collimated into a parallel beam by the collimating lens 12 and then enters the lower port of the L-shaped light tube 5. After being reflected by the reflecting mirror 4 in the L-shaped light tube 5, it is emitted from the upper port of the L-shaped light tube 5 to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light tube is reflected by the concave mirror 6 and enters the receiving mirror. The reflected beam that enters the receiving mirror 9 is focused by the receiving mirror 9 onto the photodetector 10.

[0024] Furthermore, the top of the collimating lens tube 11 is connected to an aperture 7 for pressing the collimating lens 12, and the top of the aperture 7 extends to form an extension sleeved on the outside of the L-shaped light tube 5.

[0025] Furthermore, the concave mirror 6 is a spherical concave mirror 6.

[0026] Furthermore, the concave mirror 6 is a parabolic concave mirror 6.

[0027] Furthermore, the projection of the concave mirror 6 onto the receiving mirror 9 is within the receiving range of the receiving mirror 9.

[0028] Furthermore, the concave mirror 6 is positioned at the outer corner of the L-shaped light-transmitting tube 5. The width of the concave mirror 6 in the horizontal direction is greater than the outer diameter of the L-shaped light-transmitting tube 5.

[0029] The optical path principle of the lidar in this utility model is as follows: the laser beam emitted from the laser emitter 13 is collimated into a parallel beam by the collimating lens 12 and then enters the lower port of the L-shaped light tube 5. After being reflected by the reflector 4, it is emitted from the upper port of the L-shaped light tube 5 and finally passes through the optical cover 2 and is projected onto the target object. When the parallel laser beam projected onto the target object undergoes diffuse reflection on the surface of the target object, part of the laser beam is reflected back to the upper port of the L-shaped light tube 5. This part of the light is either reflected by the reflector 4 and emitted from the lower port of the L-shaped light tube 5, blocked by the laser emitting component or blocked by the tube wall of the L-shaped light tube 5, and cannot be effectively received by the photoelectric detector 10. Another part of the laser beam is diffusely reflected by the target object to the area outside the L-shaped light tube 5. The closer the target object is to the lidar, the larger the angle between the laser beam diffusely reflected to the area outside the L-shaped light tube 5 and the receiving optical axis, and the smaller the proportion of light that meets the receiving field of view requirements (the angle with the receiving optical axis is less than a specific value). When the distance between the target object and the lidar is less than a specific distance value, the proportion is zero, and the area within this specific distance is the receiving blind zone. In order to project the laser echoes that are diffusely reflected by the target object to the outside of the L-shaped light tube 5 (whether they are outside the receiving field of view or blocked within the receiving field of view) onto the receiving mirror 9 and thus be detected by the photodetector 10, the laser radar receiving blind spot compensation device of this utility model sets a concave mirror 6 at the outer corner of the L-shaped light tube 5 to shape and reflect part of the laser beam diffusely reflected to the area below the L-shaped light tube 5 to the receiving mirror 9, and then converges it to the photodetector 10 through the receiving mirror 9.

[0030] By applying this utility model, at least the following technical effects are achieved: 1. This invention utilizes a concave mirror 6 positioned at the outer corner of an L-shaped light-transmitting tube 5. Light rays generated by a nearby target that cannot be effectively detected due to obstruction by the L-shaped light-transmitting tube 5 or exceeding the receiving field of view are shaped and reflected by the concave mirror 6 to the receiving mirror 9, and then converged onto the photodetector 10. This blind spot compensation mechanism improves the capture rate of diffusely reflected light from nearby targets, reduces the near-range detection blind zone of the coaxial laser radar, and thus expands the near-range measurement range of the laser radar.

[0031] 2. This utility model uses a concave mirror 6 to shape and reflect echo lasers that are outside the receiving field of view or blocked within the receiving field of view. Compared with a plane mirror, the concave mirror 6 has a stronger light-gathering ability.

[0032] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this utility model.

[0033] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A receiver blind spot compensation mechanism for lidar, characterized in that, Including a concave mirror positioned outside the L-shaped light-transmitting tube of the lidar; The output beam of the lidar passes through the lower port of the lidar's L-shaped light tube, and after being reflected at the corner inside the L-shaped light tube, it is emitted from the upper port of the L-shaped light tube to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light tube is reflected by the concave mirror and then enters the receiving mirror.

2. The reception blanking mechanism of the laser radar according to claim 1, wherein The concave mirror is a spherical concave mirror.

3. The reception blanking mechanism of the laser radar according to claim 1, wherein A concave mirror is a parabolic concave mirror.

4. The receiving blind-mechanism of the laser radar according to claim 1, wherein The projection of the concave mirror onto the receiving mirror of the lidar is within the receiving range of the receiving mirror.

5. The receive blanking mechanism of a lidar according to claim 1, wherein, The concave mirror is positioned at the outer corner of the L-shaped light tube of the lidar.

6. A lidar, characterized in that, Includes housing, optical cover, reflector rotation assembly, laser transceiver assembly, and concave mirror; The bottom of the optical cover is connected to the top of the housing, and the reflective rotating component and the laser transceiver component are distributed vertically within the cavity formed by the optical cover and the housing; The mirror rotation assembly includes a motor, a mirror, and an L-shaped light-transmitting tube; the motor is fixed inside the top of the optical cover, the mirror is connected to the output shaft of the motor, and the L-shaped light-transmitting tube is connected to the mirror surface of the mirror; The laser transceiver assembly includes a receiver mount, a photodetector, a receiver, a collimating tube, a collimating lens, and a laser transmitter. The receiver mount is located at the bottom of the housing, the photodetector is located on the bottom surface of the receiver mount, the receiver is connected to the top of the receiver mount, the collimating tube passes through the central axis of the receiver, and the collimating lens and the laser transmitter are located at the top and bottom of the collimating tube, respectively. The laser beam emitted by the laser emitter is collimated into a parallel beam by a collimating lens and then enters the lower port of the L-shaped light tube. After being reflected by a mirror in the L-shaped light tube, it exits from the upper port of the L-shaped light tube to the nearby target, generating a diffuse reflection beam. A portion of the diffuse reflection beam that does not enter the L-shaped light tube is reflected by a concave mirror and enters the receiving mirror. The diffuse reflection beam that enters the receiving mirror is focused by the receiving mirror onto the photodetector.

7. The lidar of claim 6, wherein, The concave mirror is a spherical concave mirror.

8. The lidar of claim 6, wherein, A concave mirror is a parabolic concave mirror.

9. The lidar of claim 6, wherein, The projection of the concave mirror onto the receiving mirror is within the receiving range of the receiving mirror.

10. The lidar of claim 6, wherein, The concave mirror is positioned at the outer corner of the L-shaped light-transmitting tube.

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