Extinction lens tube and lidar

Abstract

This application relates to the field of lidar technology and provides an extinction lens barrel and a lidar system. The extinction lens barrel includes a lens barrel body with a first optical channel and a first mounting slot. A three-dimensional extinction structure is disposed on the lens barrel body. The first mounting slot is located at the light output end of the first optical channel and is used to mount a beam splitter. The three-dimensional extinction structure is located on one side of the first mounting slot and is used to reflect and / or absorb stray light to the outside of the lens barrel body. According to Lambert's law, Ii = In·cosi, the three-dimensional extinction structure of this application differs from the common single-sloping-plane extinction. With the structural dimensions unchanged, the three-dimensional extinction structure can significantly increase the tilt angle of the remaining reflected light hitting the inclined plane, so that more stray light is reflected or directly absorbed, effectively reducing the stray light diffusely reflected back to the receiving optical system, thereby improving the detection accuracy of the lidar.

Description

Technical Field

[0001] This application belongs to the field of lidar technology, and more specifically, relates to an extinction lens tube and lidar. Background Technology

[0002] A lidar is a device that detects the three-dimensional spatial position or velocity of a target object by emitting laser signals and receiving echo signals. While receiving echo signals, existing lidar systems inevitably also receive noise signals from nature, such as sunlight or other light sources. Furthermore, backscattered light from the laser signal during propagation, signals from other lidar systems, and stray light signals generated within the optical system can also affect the lidar system's detection, reducing its signal-to-noise ratio and detection probability.

[0003] In practical applications, based on different working principles, lidar can be divided into: triangulation-based lidar, time-of-flight (TOF) lidar, and phase-based lidar; and based on different structures, lidar can be divided into: coaxial lidar and non-coaxial lidar.

[0004] Please refer to Figure 1 The basic form of the coaxial optical path of a current lidar is as follows: the laser is emitted from the light source, collimated into approximately parallel light by the collimation system, exits through the transmission surface of the perforated reflector, and illuminates the object being measured. The light diffusely reflected by the object is reflected by the reflection surface of the perforated reflector and the deflector, and then focused onto the receiving device by the receiving optical system.

[0005] like Figure 2 As shown, the existing perforated reflector has the following specific form: the transmitting surface is coated with a film with transmission function, and the reflecting surface is coated with a film with reflection function. The laser collimated spot exits through the transmitting surface. Since the laser collimated spot is smaller than the aperture of the receiving optical system, part of the light diffusely reflected by the object can be partially reflected back to the receiving optical system through the reflecting surface, achieving coaxial transmission and reception.

[0006] Since the perforated reflector cannot achieve 100% transmission, the untransmitted light will form stray light in the mirror tube after being reflected by the transmission surface. The stray light will then pass through diffuse reflection and the perforated reflector transmission surface and return directly to the receiving device through the receiving optical system.

[0007] In the above scheme, the coaxial optical path will generate internal stray light, which will directly pass through the receiving optical system to reach the receiving device, interfering with the echo signal and affecting the detection accuracy of the lidar. Therefore, it needs to be improved. Summary of the Invention

[0008] The purpose of this application is to provide an extinction lens barrel and a lidar to solve the following technical problems:

[0009] Existing lidar coaxial optical paths generate internal stray light that directly passes through the receiving optical system to the receiving device, interfering with the echo signal and affecting the lidar's detection accuracy.

[0010] To achieve the above objectives, firstly, the technical solution adopted in this application is:

[0011] An extinction lens barrel is provided, including a lens barrel body, the lens barrel body having a first optical channel and a first mounting groove, a three-dimensional extinction structure being provided on the lens barrel body, the first mounting groove being located at the light output end of the first optical channel, the first mounting groove being used to mount a beam splitter, and the three-dimensional extinction structure being located on one side of the first mounting groove and being used to reflect stray light and / or absorb stray light to the outside of the lens barrel body.

[0012] In one feasible technical solution of this application, the first optical channel is arranged along the X-axis direction, and the three-dimensional extinction structure includes an X-axis reflecting slope, a Y-axis reflecting slope and a Z-axis reflecting slope. The X-axis reflecting slope is projected inclined in the X-axis direction, the Y-axis reflecting slope is projected inclined in the Y-axis direction, and the Z-axis reflecting slope is projected inclined in the Z-axis direction.

[0013] In one feasible technical solution of this application, diffuse reflection structures are provided on the X-axis reflecting slope, the Y-axis reflecting slope, and the Z-axis reflecting slope.

[0014] In one feasible technical solution of this application, the diffuse reflection structure is a material coating or a matte tooth.

[0015] To achieve the above objectives, secondly, the technical solution adopted in this application is:

[0016] A lidar is provided, including the above-described extinction lens tube, wherein a beam splitter is installed in the first mounting slot.

[0017] In one feasible technical solution of this application, the angle between the beam splitter and the first optical channel is between 40 and 50 degrees.

[0018] In one feasible technical solution of this application, the beam splitter is a punched-hole reflector, and the surface of the punched-hole reflector is provided with a transmission surface region and a reflection surface region, wherein the transmission surface region is located within the reflection surface region.

[0019] In one feasible technical solution of this application, a coating layer with a transmission function is provided on the transmissive surface region, and a coating layer with a reflection function is provided on the reflective surface region.

[0020] In one feasible technical solution of this application, the lens barrel body is further provided with a second optical channel and a second mounting groove. The second optical channel is arranged parallel to and spaced apart from the first optical channel. The second mounting groove is located at the optical input end of the second optical channel. The first mounting groove and the second mounting groove are located at the same end of the lens barrel body.

[0021] The lidar also includes a reflector, a laser emitter, a collimating lens group, and a receiver mounted on the lens barrel body. The reflector is mounted in the second mounting slot, the collimating lens group is located in the first optical channel, the laser emitter is located at the end of the first optical channel away from the first mounting slot, and the receiver is located at the end of the second optical channel away from the second mounting slot.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] Stray light reflected by the beam splitter will strike the nearby three-dimensional extinction structure. According to Lambert's law, Ii = In·cosi, the three-dimensional extinction structure differs from the common single-sloping-plane extinction. With the structural dimensions unchanged, compared with the conventional lens tube structure, the three-dimensional extinction structure can significantly increase the tilt angle of the remaining reflected light hitting the inclined plane, so that more stray light is reflected or directly absorbed, effectively reducing the stray light diffusely reflected back to the receiving optical system, thereby improving the detection accuracy of lidar. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram illustrating the basic principle of the coaxial optical path in existing lidar technologies.

[0026] Figure 2 This is a schematic diagram of the structure of a perforated reflector in the prior art.

[0027] Figure 3 This is a three-dimensional structural diagram of the matting lens tube in an embodiment of this application.

[0028] Figure 4 This is a front view of the extinction lens tube in an embodiment of this application, to show the structure of the X-axis reflective slope.

[0029] Figure 5This is a left sectional view of the extinction lens tube in an embodiment of this application, to show the structure of the Z-axis reflective slope.

[0030] Figure 6 This is a top sectional view of the extinction lens tube in an embodiment of this application, to show the structure of the Y-axis reflective slope.

[0031] Figure 7 This is a schematic diagram of the internal structure of the lidar in an embodiment of this application.

[0032] The following are the labeling elements in the figure:

[0033] 100. Lens tube body; 11. First optical channel; 12. First mounting slot; 13. Three-dimensional extinction structure; 131. X-axis reflecting slope; 132. Y-axis reflecting slope; 133. Z-axis reflecting slope; 14. Second optical channel; 15. Second mounting slot;

[0034] 200. Beam splitter;

[0035] 300. Reflector;

[0036] 400. Laser emitter;

[0037] 500, collimating lens group;

[0038] 600, Receiver. Detailed Implementation

[0039] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0040] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0041] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0043] Currently, lidar systems are widely used in the field of intelligent driving, playing an important role in distance measurement, target recognition, and road monitoring.

[0044] In the field of intelligent driving, lidar systems can perceive the driving environment. The working principle is to emit collimated detection light into the surrounding environment through a laser emitter, and receive the reflected light formed when the detection light encounters the object being measured in the surrounding environment through a laser receiver. Then, the position, size and other information of the object in the surrounding environment can be calculated using the time-of-flight method.

[0045] A lidar is a device that detects the three-dimensional spatial position or velocity of a target object by emitting laser signals and receiving echo signals. While receiving echo signals, existing lidar systems inevitably also receive noise signals from nature, such as sunlight or other light sources. Furthermore, backscattered light from the laser signal during propagation, signals from other lidar systems, and stray light signals generated within the optical system can also affect the lidar system's detection, reducing its signal-to-noise ratio and detection probability.

[0046] LiDAR has advantages such as high accuracy, fast operation speed and high efficiency, and is an indispensable core sensor in fields such as autonomous driving, robot positioning and navigation, space environment mapping, and security.

[0047] In practical applications, based on different working principles, lidar can be divided into: triangulation-based lidar, time-of-flight (TOF) lidar, and phase-based lidar; and based on different structures, lidar can be divided into: coaxial lidar and non-coaxial lidar.

[0048] In order to effectively solve the following technical problems objectively existing in the existing lidar technology: "The coaxial optical path will generate internal stray light, which directly passes through the receiving optical system to reach the receiving device, interfering with the echo signal and affecting the detection accuracy of lidar", the technical solution of this application is provided.

[0049] Please refer to the following: Figures 2-7 The extinction lens barrel and lidar provided in the embodiments of this application will now be described.

[0050] This application provides an example of an matte lens tube; please refer to [link / reference]. Figures 3 to 6 The system includes a lens barrel body 100, which has a first optical channel 11 and a first mounting groove 12. A three-dimensional extinction structure 13 is provided on the lens barrel body 100. The first mounting groove 12 is located at the light output end of the first optical channel 11 and is used to mount a beam splitter 200. The three-dimensional extinction structure 13 is located on one side of the first mounting groove 12 and is used to reflect stray light and / or absorb stray light to the outside of the lens barrel body 100.

[0051] Specifically, the lens barrel body 100 is a plastic structure, wherein the three-dimensional matting structure 13 is integrally injection molded inside the lens barrel body 100.

[0052] The matting lens barrel provided in this application has the following foreseeable beneficial technical effects compared with the prior art:

[0053] Stray light reflected by beam splitter 200 will hit the nearby three-dimensional extinction structure 13. According to Lambert's law, Ii = In·cosi, the three-dimensional extinction structure 13 is different from the common single-sloping surface extinction. With the structural size unchanged, compared with the conventional lens tube structure, the three-dimensional extinction structure 13 can significantly increase the tilt angle of the remaining reflected light hitting the slope, so that more stray light is reflected or directly absorbed, effectively reducing the stray light diffusely reflected back to the receiving optical system, thereby improving the detection accuracy of lidar.

[0054] Specifically, to facilitate a quick understanding of this solution by those skilled in the art, the first optical channel 11 is arranged along the X-axis direction, and the three-dimensional extinction structure 13 includes an X-axis reflecting slope 131, a Y-axis reflecting slope 132, and a Z-axis reflecting slope 133. The X-axis reflecting slope 131 is projected with an inclined projection in the X-axis direction, the Y-axis reflecting slope 132 is projected with an inclined projection in the Y-axis direction, and the Z-axis reflecting slope 133 is projected with an inclined projection in the Z-axis direction.

[0055] Furthermore, diffuse reflection structures are provided on the X-axis reflecting slope 131, Y-axis reflecting slope 132 and Z-axis reflecting slope 133 to significantly enhance the ability of the three-dimensional extinction structure 13 to reflect stray light and / or absorb stray light.

[0056] Specifically, in this embodiment, the diffuse reflection structure is a material coating; in other embodiments, the diffuse reflection structure may also be appropriately sized matting teeth.

[0057] This application also provides a lidar system; please refer to [link / reference]. Figure 3 and Figure 7 Including the aforementioned extinction lens tube, a beam splitter 200 is installed in the first mounting slot 12.

[0058] In one feasible technical solution of this application, the angle between the beam splitter 200 and the first optical channel 11 is between 40 and 50 degrees. In this embodiment, the angle is preferably 45 degrees.

[0059] Please refer to again Figure 2 The beam splitter 200 is a perforated reflector 300, and the surface of the perforated reflector 300 is provided with a transmission surface area and a reflection surface area.

[0060] The transmissive surface region is located within the reflective surface region. A coating layer with a transmissive function is provided on the transmissive surface region, and a coating layer with a reflective function is provided on the reflective surface region.

[0061] For the purpose of quick and easy understanding by those skilled in the art, the transmissive surface area is referred to as the transmissive surface, and the reflective surface area is referred to as the reflective surface.

[0062] In this embodiment, the lens barrel body 100 is also provided with a second optical channel 14 and a second mounting groove 15. The second optical channel 14 is arranged parallel to and spaced apart from the first optical channel 11. The second mounting groove 15 is located at the light input end of the second optical channel 14. The first mounting groove 12 and the second mounting groove 15 are located at the same end of the lens barrel body 100.

[0063] The lidar also includes a reflector 300, a laser emitter 400, a collimating lens group 500, and a receiver 600 mounted on the lens barrel body 100.

[0064] The reflector 300 is installed in the second mounting slot 15, the collimating lens group 500 is located in the first optical channel 11, the laser emitter 400 is located at the end of the first optical channel 11 away from the first mounting slot 12, and the receiver 600 is located at the end of the second optical channel 14 away from the second mounting slot 15.

[0065] Based on the numerous advantages of the aforementioned extinction lens tube, the lidar also possesses the aforementioned advantages through the above technical solution, namely:

[0066] Stray light reflected by beam splitter 200 will hit the nearby three-dimensional extinction structure 13. According to Lambert's law, Ii = In·cosi, the three-dimensional extinction structure 13 is different from the common single-sloping surface extinction. With the structural size unchanged, compared with the conventional lens tube structure, the three-dimensional extinction structure 13 can significantly increase the tilt angle of the remaining reflected light hitting the slope, so that more stray light is reflected or directly absorbed, effectively reducing the stray light diffusely reflected back to the receiving optical system, thereby improving the detection accuracy of lidar.

[0067] The laser beam emitted by the laser emitter 400 passes sequentially through the first optical channel 11 and the collimating lens group 500, and then through the beam splitter 200 before being emitted outward. After being reflected by the target object in the detection area, the reflected light signal returns. The reflected light signal is received and deflected by the beam splitter 200, and then reflected by the reflector 300 to be received by the receiver 600.

[0068] Through the above technical solutions, the components arranged in a straight line have a higher degree of integration, a higher space utilization rate, and a more compact internal structure and smaller size for the entire product.

[0069] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A matte lens tube, characterized in that, The system includes a lens barrel body (100), which has a first optical channel (11) and a first mounting groove (12). A three-dimensional extinction structure (13) is provided on the lens barrel body (100). The first mounting groove (12) is located at the light output end of the first optical channel (11). The first mounting groove (12) is used to mount a beam splitter (200). The three-dimensional extinction structure (13) is located on one side of the first mounting groove (12) and is used to reflect stray light and / or absorb stray light to the outside of the lens barrel body (100). The first optical channel (11) is arranged along the X-axis direction. The three-dimensional extinction structure (13) includes an X-axis reflecting slope (131), a Y-axis reflecting slope (132), and a Z-axis reflecting slope (133). The X-axis reflecting slope (131) is projected inclined in the X-axis direction, the Y-axis reflecting slope (132) is projected inclined in the Y-axis direction, and the Z-axis reflecting slope (133) is projected inclined in the Z-axis direction.

2. The matting lens tube as described in claim 1, characterized in that, The X-axis reflecting slope (131), the Y-axis reflecting slope (132), and the Z-axis reflecting slope (133) are all provided with diffuse reflection structures.

3. The matting lens tube as described in claim 2, characterized in that, The diffuse reflection structure is a material coating or a matte finish.

4. The matting lens tube as described in claim 1, characterized in that, The lens barrel body (100) is also provided with a second optical channel (14) and a second mounting groove (15). The second optical channel (14) is arranged parallel to and spaced apart from the first optical channel (11). The second mounting groove (15) is located at the light input end of the second optical channel (14). The second mounting groove (15) is used to install the reflector (300). The first mounting groove (12) and the second mounting groove (15) are located at the same end of the lens barrel body (100).

5. A lidar, characterized in that, Includes an extinction lens tube as described in any one of claims 1 to 4, wherein a beam splitter (200) is installed in the first mounting groove (12).

6. The lidar as described in claim 5, characterized in that, The angle between the beam splitter (200) and the first optical channel (11) is between 40 and 50 degrees.

7. The lidar as described in claim 5, characterized in that, The beam splitter (200) is a perforated reflector (300), and the surface of the perforated reflector (300) is provided with a transmission surface area and a reflection surface area, and the transmission surface area is located in the reflection surface area.

8. The lidar as described in claim 7, characterized in that, The transmissive surface region is provided with a coating layer that has a transmissive function, and the reflective surface region is provided with a coating layer that has a reflective function.

9. The lidar as described in claim 5, characterized in that, The lens barrel body (100) is also provided with a second optical channel (14) and a second mounting groove (15). The second optical channel (14) is arranged parallel to and spaced apart from the first optical channel (11). The second mounting groove (15) is located at the light input end of the second optical channel (14). The first mounting groove (12) and the second mounting groove (15) are located at the same end of the lens barrel body (100). The lidar also includes a reflector (300), a laser emitter (400), a collimating lens group (500), and a receiver (600) mounted on the lens barrel body (100). The reflector (300) is mounted in the second mounting slot (15), the collimating lens group (500) is located in the first optical channel (11), the laser emitter (400) is located at the end of the first optical channel (11) away from the first mounting slot (12), and the receiver (600) is located at the end of the second optical channel (14) away from the second mounting slot (15).

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