Outer protection structure of laser radar and laser radar
By adopting the design of a hemispherical optical window and locking sleeve in the external protection structure of the lidar, the problems of laser beam morphology and energy loss are solved, and more efficient ranging and wider scope of application are achieved.
Patent Information
- Application Number
- CN202421300276.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-06-07
AI Technical Summary
The external protection structure of existing lidar cannot effectively maintain the beam form of laser light, resulting in beam energy loss and affecting distance measurement capability.
A hemispherical optical window is used as the core component of the outer protection structure. By setting up a locking sleeve and an outer shell, a sealed cavity is formed to ensure that the laser light signal is not disturbed and the incoming channel is maintained, and the beam form is maintained.
It effectively reduces the energy loss of the laser beam, maintains the shape of the beam, improves the distance measurement ability, and provides dust-proof and waterproof protection, enhancing the comprehensive performance of the external protection structure.
Smart Images
Figure CN223006299U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lidar based on photoelectric detection, in particular to an outer protection structure of a lidar and a lidar. Background Art
[0002] A lidar measures the spatial position of an object in the environment by emitting a laser signal and receiving its echo signal, so as to realize three-dimensional perception of the surrounding environment. Due to the characteristics of large measurement distance, high precision, large detection range, and stability and being not easily interfered, it has been widely used in fields such as intelligent vehicles, robots, forestry exploration, pile measurement, and power inspection.
[0003] As an outer protection structure of a lidar, it is an essential structural module of the lidar device, used to protect the internal modules of the lidar, prevent damage caused by collision and impact, and at the same time has functions such as dust and water protection, to protect the normal operation of the internal opto-mechanical and electrical components of the lidar.
[0004] At the same time, in the prior art, a lidar usually having a 360-degree scanning field of view usually has a cylindrical optical window, and the curvature of each point is different. For the laser signal emitted by an EEL laser emitter, its light spot is narrow and long, and after passing through the optical window, the laser beam will be further expanded and diverged, thereby affecting the beam intensity per unit area and reducing the ranging ability. Summary of the Invention
[0005] The technical problem solved by the utility model is to provide an outer protection structure of a lidar, which forms an emission and injection channel for laser light signals, maintains the beam form of the laser light, and reduces the beam energy loss.
[0006] Furthermore, it tightly protects the internal modules of the lidar and prevents dust and water.
[0007] Furthermore, while not affecting the ranging performance of the lidar, it protects the human eye from harm, so as to enhance the comprehensive performance of the outer protection structure and expand the applicable range of the lidar.
[0008] The utility model discloses an outer protection structure of a lidar, including: a hemispherical optical window, a locking compression sleeve, and a housing shell;
[0009] The hemispherical optical window is arranged at the top of the housing shell, and is used for emitting laser light signals and injecting echo signals. The curvature of each point on the hemispherical optical window is the same. A cavity is formed inside the hemispherical optical window and the housing shell. The hemispherical optical window is used to accommodate the scanning module of the lidar to complete 360-degree scanning;
[0010] This locking bushing is used to connect and compress the hemispherical optical window and the outer shell, and ensure the sealing of the cavity.
[0011] The thickness of each point on the hemispherical optical window is the same.
[0012] This thickness is 1 mm - 3 mm.
[0013] The hemispherical optical window includes an anti-reflection film layer and a light-transmitting medium layer, or the hemispherical optical window includes an anti-reflection film layer, a light-transmitting medium layer and a self-cleaning layer.
[0014] The hemispherical optical window includes an anti-reflection film layer, a light-transmitting medium layer and an eye-safe filter layer, and the wavelength band of the eye-safe filter layer is 1540 nm - 1560 nm.
[0015] The light-transmitting medium layer is a plastic injection molding substrate layer or a glass substrate layer.
[0016] The hemispherical optical window has a first snap portion, the outer shell has a second snap portion, and the locking bushing has a U-shaped structure. The U-shaped structure realizes the connection and compression of the hemispherical optical window and the outer shell by clamping the first and second snap portions.
[0017] A clamping portion is provided at the vertex of the inner wall of the hemispherical optical window to position and support the scanning module of the lidar.
[0018] The roughness of the inner wall of the hemispherical optical window is less than 0.02 microns, and the roughness of the outer wall of the hemispherical optical window is less than 0.02 microns.
[0019] The present utility model also discloses a lidar having the outer protection structure described above.
[0020] The outer protection structure of the present utility model forms an emission and incident channel for laser light signals, maintains the beam shape of the laser light, and reduces the beam energy loss. At the same time, it tightly protects the internal modules of the lidar, prevents dust and water, and ensures the normal operation of the internal opto-mechanical and electrical components of the lidar. While not affecting the ranging performance of the lidar, it protects the human eye from harm, so as to enhance the comprehensive performance of the outer protection structure and expand the applicable range of the lidar. Description of the Drawings
[0021] Figure 1 Shown is a schematic structural diagram of an outer protection structure of a lidar according to the present utility model.
[0022] Figure 2 Shown is a schematic structural diagram of an internal structure of a lidar according to the present utility model.
[0023] Figure 3A 、 3BThe figure shows a schematic diagram of the material composition of the hemispherical optical window of the present utility model.
[0024] Figure 4 The figure shows a schematic cross-sectional view of an outer protection structure of a lidar of the present utility model. Detailed implementation manners
[0025] The following describes the implementation process of the technical solution of the present utility model in combination with specific embodiments, which shall not be construed as a limitation to the present utility model.
[0026] As Figure 1 The figure shows a schematic structural view of an outer protection structure of a lidar of the present utility model. As Figure 2 The figure shows a schematic structural view of an internal structure of a lidar of the present utility model.
[0027] The outer protection structure 100 is applied to a lidar. The outer protection structure 100 covers internal modules such as the transceiver module, optical system, scanning module, circuit board card, and mechanical structure of the lidar. It is used to protect the internal modules, ensure the normal operation of the internal opto-mechanical and electrical components of the lidar, prevent damage caused by collision and impact, and at the same time form an emission and injection channel for laser light signals, maintain the beam shape of the laser light, and reduce the beam energy loss.
[0028] In order to achieve a large scanning field of view, the internal modules of the lidar include a scanning module 40, an optical system 50, and a circuit board card 60. The transceiver module is arranged on the surface of the circuit board card 60, the optical system 50 is arranged above the circuit board card 60, and the scanning module 40 is arranged above the optical system 50. The scanning module 40 rotates around the optical axis O, the optical system 50 is arranged around the optical axis O, and other mechanical structures are used to assist in realizing the above position relationship.
[0029] The optical system 50 includes a transmitting optical lens group 52 and a receiving optical lens group 51. The transmitting optical lens group 52 is arranged around the receiving optical lens group 51. The transmitting optical lens group 52 and the receiving optical lens group 51 are coaxial, that is, both are arranged around the optical axis O. N transmitting modules correspond to the transmitting optical lens group 52 and are arranged circumferentially around the optical axis O. N receiving modules are also arranged circumferentially around the optical axis O, and the N receiving modules correspond to the receiving optical lens group 51.
[0030] The rotation of the scanning module 40 around the optical axis O can drive the N laser light signals emitted by the N transmitting modules to perform 360-degree scanning. The laser light signals need to pass through the outer protection structure 100 and enter the environment to realize the three-dimensional perception of the target objects in the environment.
[0031] The scanning module 40 includes a scanning rotation module 41 and a transmission rotation module 42. Each laser light signal is guided by the dual optical paths of the scanning rotation module 41 and the transmission rotation module 42, achieving a large field of view scanning of 360 degrees horizontally and in the vertical direction.
[0032] The outer protection structure 100 includes: a hemispherical optical window 10, a locking bushing 20, and a housing shell 30.
[0033] The hemispherical optical window 10 is disposed at the top of the housing shell 30, such that a cavity is formed inside the hemispherical optical window and the housing shell. The cavity is used to accommodate the internal modules of the lidar as Figure 2 shown. The locking bushing 20 is used to connect and compress the hemispherical optical window 10 and the housing shell 30, and ensure the sealing of the cavity.
[0034] In order to cooperate with the entry and exit of the laser light signal, the position of the hemispherical optical window 10 is set at the top to accommodate the scanning module 40, for the laser light signal to emit and the echo signal to enter to complete 360-degree scanning. That is, the scanning rotation module 41 and the transmission rotation module 42 are inserted into the hemispherical optical window 10. Since the rotation of the scanning module 40 forms a scanning field of view in a three-dimensional space band, and the scanning points are relatively uniform, in order to ensure that the optical path of the laser light signal remains the original route when passing through the hemispherical optical window 10, and there is no random optical path change and uneven energy dissipation while achieving the established scanning field of view, the optical window is set in the shape of a hemisphere, and the curvature of each point on the hemispherical optical window is the same, such that the degree of light deflection of each point on the optical window is the same, maintaining the beam shape of the laser light.
[0035] In an optimized embodiment, the thickness of each point on the hemispherical optical window is also the same, and the thickness can be 1 mm - 3 mm. To maintain the signal distribution pattern of all laser light signals when passing through the hemispherical optical window 10.
[0036] The surface roughness of the inner wall of the hemispherical optical window is less than 0.02 microns, and the surface roughness of the outer wall of the hemispherical optical window is less than 0.02 microns, to improve the quality of the emitted laser beam.
[0037] Such as Figure 3A 、 3BAs shown, the hemispherical optical window 10 may include an anti-reflection film layer 101, a light-transmitting medium layer 102, and a self-cleaning layer 103. The light-transmitting medium layer is a glass substrate layer, or the light-transmitting medium layer is a plastic injection molding substrate layer. The material of the hemispherical optical window 10 can efficiently maintain the light energy of the laser light signal, while avoiding the attachment of impurities to the window as much as possible, thereby ensuring that the laser radar has a longer ranging capability. Alternatively, the hemispherical optical window 10 only includes the anti-reflection film layer 101 and the light-transmitting medium layer 102, and the anti-reflection film layer 101 is arranged on the outer layer.
[0038] In another embodiment, the hemispherical optical window includes an anti-reflection film layer 101, a light-transmitting medium layer 102 and a human eye safety filter layer 104, or the hemispherical optical window includes a light-transmitting medium layer 102 and a human eye safety filter layer 104. The transmitting module can be selected as a transmitting module for transmitting a 1550nm laser light signal. Electromagnetic wave signals at 1400-2000nm are relatively safe for the human eye, so the wavelength of the human eye safety filter layer 104 is 1540nm-1560nm. The human eye safety filter layer 104 is a black filter film and can be made of silicon dioxide or polycrystalline silicon. By setting the human eye safety filter layer 104, the human eye can be protected from harm without affecting the ranging performance of the laser radar, so as to enhance the comprehensive performance of the external protection structure and expand the scope of application of the laser radar.
[0039] like Figure 4 The figure shows a cross-sectional schematic diagram of an outer protection structure of a laser radar of the present invention.
[0040] The hemispherical optical window has a dome structure and a first buckle portion 106 . As can be seen from the cross section, the cross section of the hemispherical optical window is Ω-shaped.
[0041] The upper edge of the outer shell 30 has a second buckle portion 301. The locking sleeve 20 is annular, and its cross section has a U-shaped structure 201, and the U-shaped structure 201 realizes the connection and compression of the hemispherical optical window and the outer shell by clamping the first and second buckle portions.
[0042] The first side wall of the U-shaped structure 201 presses the first snap-on portion 106, the upper second snap-on portion 301 of the outer shell shell 30 is hook-shaped, and the first side wall of the U-shaped structure 201 presses the second snap-on portion 301. A sealing strip can also be arranged between the first snap-on portion 106 and the second snap-on portion 301 to further clamp them to prevent water vapor or dust from entering the internal cavity of the outer protective structure and contaminating the internal optomechanical components of the laser radar.
[0043] A clamping part 105 is further arranged at the vertex of the inner wall of the hemispherical optical window. The clamping part 105 is used to position and support the scanning module of the lidar, especially the scanning and rotating module 41, so that the scanning and rotating module 41 is attached to the inner wall of the hemispherical optical window and rotates stably around the optical axis O to avoid eccentricity.
[0044] The outer protection structure of the present utility model serves as a channel for the laser beam to emit and enter, reduces the energy loss of the beam, and maintains the beam shape of the laser light. At the same time, it tightly protects the internal modules of the lidar, prevents dust and water, and ensures the normal operation of the internal opto-mechanical and electrical components of the lidar. While not affecting the ranging performance of the lidar, it protects the human eye from harm to enhance the comprehensive performance of the outer protection structure and expand the application range of the lidar.
[0045] The above embodiments are only used to describe the technical solutions of the present utility model and are not regarded as limitations to the present utility model.
Claims
1. An outer protection structure of a laser radar, characterized in that: include: Hemispherical optical window, locking sleeve and outer shell; The hemispherical optical window is arranged at the top of the shell body, and is used for the emission of laser light signals and the injection of echo signals. The curvature of each point on the hemispherical optical window is the same. The hemispherical optical window and the inside of the shell body form a cavity. The hemispherical optical window is used to accommodate the scanning module of the laser radar to complete 360-degree scanning. The locking sleeve is used to connect and compress the hemispherical optical window and the outer shell, and ensure the sealing of the cavity.
2. The outer protection structure of the laser radar according to claim 1, characterized in that: The thickness of each point on the hemispherical optical window is the same.
3. The outer protection structure of the laser radar according to claim 2, characterized in that: The thickness is 1 mm-3 mm.
4. The outer protection structure of the laser radar according to claim 1, characterized in that: The hemispherical optical window includes an anti-reflection film layer and a light-transmitting medium layer, or the hemispherical optical window includes an anti-reflection film layer, a light-transmitting medium layer and a self-cleaning layer.
5. The outer protection structure of the laser radar according to claim 1, characterized in that: The hemispherical optical window comprises a light-transmitting medium layer and an eye-safe filter layer, and the waveband of the eye-safe filter layer is 1540nm-1560nm.
6. The outer protection structure of the laser radar according to claim 4 or 5, characterized in that: The light-transmitting medium layer is a plastic injection-molded substrate layer or a glass substrate layer.
7. The outer protection structure of the laser radar according to claim 1, characterized in that: The hemispherical optical window has a first snap-fit portion, the outer shell has a second snap-fit portion, and the locking sleeve has a U-shaped structure. The U-shaped structure realizes the connection and compression of the hemispherical optical window and the outer shell by clamping the first and second snap-fit portions.
8. The outer protection structure of the laser radar according to claim 1, characterized in that: A fixing portion is provided at the vertex of the inner wall of the hemispherical optical window to position and support the scanning module of the laser radar.
9. The outer protection structure of the laser radar according to claim 1, characterized in that: The roughness of the inner wall of the hemispherical optical window is less than 0.02 microns, and the roughness of the outer wall of the hemispherical optical window is less than 0.02 microns.
10. A laser radar, characterized in that: The invention has an outer protective structure as claimed in any one of claims 1 to 9.