Window for laser radar and laser radar

Abstract

The utility model relates to a window for a laser radar, and the laser radar comprises a receiving and transmitting module which is configured to be used for generating emitted light and receiving echo light; the scanning device is configured to be used for enabling the emitted light from the receiving and transmitting module to deflect to the window, the emitted light is emitted after transmitting through the window and is reflected by a target to form echo light, and the scanning device is further configured to be used for enabling the echo light transmitting through the window to deflect to the receiving and transmitting module. The receiving and transmitting module is used for receiving and detecting the echo light; wherein the inner surface and / or the outer surface of the window are / is a continuous surface, and each point on the continuous surface has curvature in at least one direction.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of laser radar and more particularly, to a window for laser radar and a laser radar comprising the window. BACKGROUND

[0002] Laser radar (LIDAR) is a commonly used ranging technology, which has the characteristics of long detection distance, high resolution, and small environmental interference, and is widely used in intelligent robots, unmanned aerial vehicles, unmanned driving and other fields. In recent years, with the rise of autonomous driving technology, laser radar as an important detection component has been paid more and more attention. Laser radar is a radar system that detects the position, speed and other characteristic quantities of a target by emitting a laser beam. Its working principle is to emit a detection signal (laser beam) to the target, then compare the received echo signal reflected from the target with the transmitted signal, and after appropriate processing, the relevant information of the target such as target distance, direction, height, speed, attitude, and even shape can be obtained, so as to detect, track and identify targets such as cars and pedestrians.

[0003] When the light beam passes through the surface of the optical device, it will be reflected and / or transmitted. When the window material of the laser radar reaches a certain reflectivity, the laser beam will be reflected multiple times inside the laser radar during transmission out of the window, resulting in multiple exit spots, which in turn can form noise points on the point cloud, and thus can affect the detection effect of the laser radar.

[0004] Specifically, Figure 1A A schematic diagram showing the emission beam path of the laser radar is shown. The laser radar can include an emission unit 11, a mirror 13 and a window 15. The emission unit 11 can be used to emit a light beam (as shown by the solid line in Figure 1A When the emitted light beam reaches the window 15 via reflection of the mirror 13, part of it is transmitted through the window 15 to reach the target 17 (which can be referred to as the main beam, as shown by the solid line), and the other part is reflected by the window 15 to the mirror 13, then reflected by the mirror 13 and transmitted through the window 15 to reach the interference object 19 (which can be referred to as the stray emission beam, as shown by the dashed line).

[0005] Figure 1B A schematic diagram showing the reception beam path of the laser radar is shown. The laser radar can also include a detection unit 12. For the main beam and the stray emission beam generated by the same light beam, the main beam reflected by the target 17 and the stray echo beam reflected by the interference object 15 have the same path after reflection of the mirror 13 when received by the laser radar, so the main beam and the stray echo beam will be received by the same detection unit 12. Specifically, the main beam Figure 1B(As shown by the solid line) After being reflected by target 17, the stray emitted beam passes through window 15 and is then reflected back to detection unit 12 by mirror 13. The stray emitted beam forms a stray echo beam after reaching the interfering object 19. Figure 1B (As shown by the dashed line in the middle), the stray echo beam passes through the viewing window 15, and after being reflected sequentially by the reflector 13, the viewing window 15 and the reflector 13, it follows the same path as the main echo beam and is also received by the detection unit 12.

[0006] The detection of stray light affects the detection of the main beam, creating noise in the point cloud and thus impacting the lidar's ability to detect targets. Therefore, a solution is needed to avoid or reduce the impact of stray light.

[0007] Based on the different layouts of the transmitting and receiving optical paths, lidar can be divided into off-axis and coaxial transceiver schemes. In the off-axis transceiver scheme, the transmitting and receiving optical paths are independent and are usually implemented using different mirror groups, each responsible for the laser transmission and reception functions. In the coaxial transceiver scheme, the transmitting and receiving optical paths at least partially share the optical axis and often share a single transceiver mirror group. The separation and combining of the transmitting and receiving beams are achieved through beam splitting elements (such as partial reflectors, pinhole reflectors, polarizing beam splitters, etc.).

[0008] Figure 2 This diagram illustrates the propagation paths of stray emitted light and stray echo light in a lidar system employing a side-axis transceiver when using a planar viewport. Figure 2 In this system, the lidar adopts a side-axis transceiver scheme. The lidar can use the rotating mirror 22 for scanning, and the window 24 is a planar window. Figure 2 In the illustrated off-axis transceiver scheme, the transmitting device 21 and the receiving device 23 are separate, for example... Figure 2 The transmitting device 21 and the receiving device 23 are arranged vertically to separate the transmitting beam emitted by the transmitting device 21 and the echo beam received by the receiving device 23, so that the transmission paths of some beams will not be the same.

[0009] The reflector of rotating mirror 22 typically has a reflectivity of 99%, which is suitable for lidar such as... Figure 2 When the planar window 24 is used, the main beam will generate stray emission beam 25 within a specific angle after one or more secondary reflections through the window 24. When the stray echo beam 26 is received, after one or more secondary reflections through the window 24 and then reflected by the mirror of the rotating mirror 22, it will have the same path as the main beam. Therefore, the main beam and the stray echo beam 26 will be received by the same detection unit 23, resulting in noise on the point cloud.

[0010] To avoid noise in point clouds, methods such as... Figure 3The window 34 shown is comprised of a first part (upper part) 34a and a second part (lower part) 34b, wherein the first part 34a and the second part 34b form an angle between them. Figure 3 As shown, the upper and lower parts of the window 34 are optimized to form a certain angle, so that the transmission and reception paths of the stray beam are inconsistent, thus preventing the stray light from being received by the detection unit 23 and avoiding the formation of noise on the point cloud. Specifically, during reception, since the lower part 34b and the upper part 34a of the window 34 form a certain angle, the transmission and reception paths of the main beam transmitted through the window 34 remain unchanged, while the stray echo light, after secondary reflection through the window 34b, will be deflected in the vertical direction, thus separating from the main beam.

[0011] However, the above combination Figure 3 The design of window 34 described above is only applicable to off-axis optical paths. For coaxial optical paths with a common transmit and receive optical path, the above solution still cannot avoid noise on the point cloud.

[0012] Specifically, when the lidar adopts a coaxial transceiver scheme (such as...) Figure 4 As shown, the lidar may include a transmitting unit 41, a reflector 40, a viewing window 44, and a receiving unit 43. The transmission paths of the transmitted beam 41a and the echo beam 43a are substantially the same. The light spots formed by the transmitted beam 41a and the echo beam 43a on the viewing window 44 partially overlap, and even if the viewing window 44 is at a certain angle vertically, it cannot change the fact that the main beam and stray beam have the same path during reception.

[0013] like Figure 5 As shown, the lidar employs a coaxial transceiver scheme and can include a transceiver unit 51, a rotating mirror 52, and a viewing window 53. In the lidar scheme using the rotating mirror 52, secondary reflections typically occur between the viewing window 53 and the rotating mirror 52, causing a false point 50c (noise point) to appear in the direction of another target 50b at certain angles, where a target 50a in one direction might be in that direction. Specifically, the signal detection capability of the light-receiving path corresponding to the noise point formed by the secondary reflection (coaxial transceiver unit 51 - rotating mirror 52 - viewing window 53 - rotating mirror 52 - viewing window 53 - target 50a) is approximately β of the main beam. 2 The value is 10 times, where β is the window reflectivity, typically ranging from 2% to 10%. For example, a PC window has a reflectivity of 10%, while a glass window has a reflectivity of 5%.

[0014] It can be seen that in the transceiving paraxial scheme, the noise problem caused by multiple reflections of the window can be solved by the corresponding windows of the transmitting module and the receiving module having an included angle, but in the transceiving coaxial scheme, the scheme does not work, that is, the existing laser radar adopting coaxial transceiving cannot solve the noise problem caused by multiple reflections of the window by the window having an included angle. Therefore, a laser radar transceiving coaxial solution capable of solving the noise problem caused by multiple reflections of the window is needed. Utility model content

[0015] To solve the above technical problems, the utility model provides a kind of window for laser radar, the laser radar includes: transceiving module is configured to generate transmitting light and receive echo light;And scanning device is configured to deflect the transmitting light from the transceiving module to the window, wherein the transmitting light transmits through the window and is emitted and forms echo light after being reflected by target, the scanning device is also configured to deflect the echo light transmitting through the window to the transceiving module, for the transceiving module receives and detects the echo light;Wherein, the inner surface and / or outer surface of the window is continuous surface, and each point on the continuous surface has curvature in at least one direction respectively.

[0016] Optionally, the points on the continuous surface are configured to at least one of the following: have a predetermined curvature in a first direction, the first direction corresponds to the scanning direction of the laser radar;Have a predetermined curvature in a second direction different from the first direction, the first direction corresponds to the scanning direction of the laser radar;Or have a corresponding predetermined curvature in the first direction and the second direction, the first direction corresponds to the scanning direction of the laser radar, and the second direction is different from the first direction.

[0017] Optionally, the curvature radii of the points on the continuous surface in the at least one direction are the same or different.

[0018] Optionally, the curvature radii of the points on the continuous surface in the at least one direction are in the range of 150mm to 400mm.

[0019] Optionally, the inner surface and / or outer surface of the window is provided with an anti-reflection film.

[0020] Optionally, the continuous surface is configured to protrude towards the external space of the laser radar, or protrude towards the internal space of the laser radar.

[0021] Optionally, the material of the window includes resin or glass.

[0022] The utility model still provides a kind of laser radar, the laser radar includes: transceiver module is configured to produce transmitting light and receive echo light;As any of the above paragraphs described window;And scanning device is configured to deflect the transmitting light from the transceiver module to the window, wherein the transmitting light is emitted after transmitting through the window and forms echo light after being reflected by target, the scanning device is also configured to deflect the echo light transmitting through the window to the transceiver module, for the transceiver module receives and detects the echo light.

[0023] Optionally, part of the light path of the transmitting light produced by the transceiver module is coaxial with part of the light path of the echo light received by the transceiver module.

[0024] Optionally, the scanning device includes a rotating mirror or a galvanometer.

[0025] Compared with the prior art, the utility model can at least achieve the following advantages:

[0026] The inner surface and / or the outer surface of the window of the utility model are continuous surfaces, and each point on the continuous surface has curvature in at least one direction, which can make the stray transmitting light formed by the transmitting light of different angles reflected by the window be projected in a divergent manner to the target during the scanning of the laser radar, and can also make the stray echo light of different angles reflected by the target be incident to the detector in a divergent manner, thereby achieving energy attenuation of the stray transmitting light and the stray echo light, effectively overcoming the noise problem, and further effectively suppressing the crosstalk phenomenon of the laser radar and improving the signal-to-noise ratio when the window is applied to the laser radar.

[0027] The points on the surface of the window can be set to have corresponding predetermined curvatures in one or more specific directions. In some embodiments, the direction of the curvature of each point on the surface of the window can be selected according to the energy distribution of the light spot, and the energy of the stray transmitting light and the stray echo light can be diverged in different directions, so that the stray transmitting light and the stray echo light reflected twice by the window can be dispersed more specifically, the noise points on the point cloud can be reduced or suppressed, and the detection effect of the laser radar can be improved.

[0028] The radius of curvature of each point on the window in a specific direction is set to be between 150mm and 400mm, so that the influence on the conventional measurement light and the echo light can be reduced, the laser radar has good long-distance measurement capability, and the formation of noise points can also be suppressed.

[0029] The inner surface and / or the outer surface of the window can be provided with an antireflection film, so that the transmittance of the window for the light beam can be improved, the intensity of the light beam reflected by the window can be reduced, and the formation of noise points can be further suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0030] For further elucidation of the embodiments of the present application, the embodiments of the present application will be specifically presented with reference to the accompanying drawings. It should be understood that these drawings can only depict typical embodiments of the present application, and therefore should not be considered as limiting the scope of protection claimed by the present application.

[0031] In addition, the main connection relationship or relative position relationship of each component is shown in the drawings, rather than all of these relationships, and each component and connection in the drawings is not necessarily drawn in proportion to the actual one.

[0032] Figure 1A A schematic diagram of a transmitting beam path of a laser radar is shown;

[0033] Figure 1B A schematic diagram of a receiving beam path of a laser radar is shown;

[0034] Figure 2 A schematic diagram of the propagation path of stray emission light and stray echo light beams of a laser radar employing paraxial transceiving when a planar window is employed is shown;

[0035] Figure 3 A schematic diagram of the propagation path of stray emission light and stray echo light beams of a laser radar employing paraxial transceiving when a window having an included angle is employed is shown;

[0036] Figure 4 A schematic diagram of an optical path of a laser radar employing coaxial transceiving is shown;

[0037] Figure 5 A schematic diagram of an optical path of a laser radar employing coaxial transceiving in which a noise point is formed is shown;

[0038] Figure 6A And Figure 6B A schematic diagram of an optical path of a laser radar including a window according to the present application is shown;

[0039] Figures 7A-7C A schematic diagram of the structure of a window according to a first embodiment of the present application is shown;

[0040] Figures 8A-8C A schematic diagram of the structure of a window according to a second embodiment of the present application is shown;

[0041] Figures 9A-9C A schematic diagram of the structure of a window according to a third embodiment of the present application is shown. DETAILED DESCRIPTION

[0042] The following detailed description refers to the accompanying drawings. The drawings show, by way of example, specific embodiments in which the claimed subject matter can be practiced. It should be noted that the following detailed description is intended to be illustrative and not limiting of the subject matter disclosed; modification and variations are possible in light of the above teachings without departing from the spirit and scope of the claimed subject matter.

[0043] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to one skilled in the art that the various embodiments described can be practiced without these specific details. In other instances, well-known structures have not been described in detail in order to avoid unnecessarily obscuring the aspects of various embodiments. Unless otherwise defined, terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0044] The terms "first", "second", etc. in the specification and claims of the present application do not imply any order, number or importance, but are only used to distinguish different components or features.

[0045] Embodiments of the present application are exemplary implementations or examples. References in the specification to "an embodiment", "one embodiment", "some embodiments", "an alternate embodiment", or "other embodiments" indicate that the alternative is included in at least some embodiments of the technology, but not necessarily all embodiments. The various appearances of "an embodiment", "one embodiment”, or "some embodiments" do not necessarily all refer to the same embodiments. Elements or aspects from one embodiment can be combined with elements or aspects from another embodiment.

[0046] To solve the above technical problems, the utility model provides a kind of for the window of laser radar, the laser radar includes: transceiver module is configured to produce emission light and receive echo light;And scanning device is configured to deflect the emission light from transceiver module to window, wherein emission light is emitted after transmitting through window and forms echo light after being reflected by target, scanning device is also configured to deflect the echo light transmitting through window to transceiver module, for transceiver module receives and detects echo light;Wherein, the inner surface and / or outer surface of window is continuous surface, and each point on continuous surface has curvature in at least one direction respectively.

[0047] The window according to the utility model can make the stray emission light formed after the reflection of the emitted light and the stray echo light formed after the reflection of the echo light be divergent or divergent after convergence to realize attenuation, can effectively overcome the noise problem, and can effectively inhibit the cross talk phenomenon of the laser radar, and improve the signal-to-noise ratio.

[0048] Figure 6A And Figure 6B A light path schematic diagram of a laser radar comprising the window according to the utility model is shown. The laser radar can comprise a transceiver module 61, a scanning device 62 and a window 63. The transceiver module 61 can be configured to generate probe light, and the generated probe light can form emitted light 62a after being deflected by the scanning device 62. The emitted light 62a can be transmitted through the window 63 and exit to a three-dimensional space. The emitted light 62a after exiting can form echo light 62b after being reflected by a target object 64. The echo light 62b can be received and detected by the transceiver module 61 after being deflected by the scanning device 62 after being transmitted through the window 63.

[0049] In order to attenuate the stray light formed after being reflected by the window 63, in the embodiments of the utility model, the inner surface 63a and / or the outer surface 63b of the window 63 is a continuous surface, and each point on the continuous surface has curvature in at least one direction respectively.

[0050] The continuous surface means that the surface is smooth and continuous without interruption or bending.

[0051] In addition, the meaning of "each point on the surface has curvature in at least one direction respectively" can be understood based on the following content. Assuming that a point E on a curved surface, the normal line of the curved surface at the point E is the z-axis, there are infinite cutting planes in different directions passing through the z-axis, each cutting plane intersects the curved surface to form an intersection line, and the curvature of the point on the intersection line represents the curvature of the point in the corresponding cutting plane direction. The point E on the continuous surface of the present application is arranged to have curvature in at least one of the directions, that is, at least one cutting plane passing through the normal line of the continuous surface at the point E intersects the curved surface to form an intersection line at the point E, and the intersection line has curvature (nonzero) at the point E. Each point on the continuous surface of the present application can have curvature in at least one direction respectively.

[0052] The window 63 can have an inner surface 63a and an outer surface 63b. In some embodiments, the points on the inner surface 63a and / or the outer surface 63b of the window 63 can have curvature in at least one direction, as described in more detail below in connection with the specific embodiments of Figures 7A-7C 、 Figures 8A-8C and Figures 9A-9C .

[0053] In the present utility model, the radius of curvature of each point on the continuous surface of the window 63 in the same direction can be the same or different. As described below in combination with specific embodiments, the radius of curvature of each point in a specific direction can be set in the range of 50mm-600mm, in the range of 100mm-500mm, or in the range of 150mm-400mm. In addition, the inner surface 63a and / or the outer surface 63b of the window 63 can be provided with an anti-reflection film to increase transmission. The continuous surface of the window 63 can be configured to protrude towards the external space of the lidar or protrude towards the internal space of the lidar, both of which can achieve the effect of making the reflected light diverge. The material of the window 63 can include resin or glass.

[0054] Example 1. Points on the window surface have a predetermined curvature in a first direction

[0055] In some embodiments, each point on the inner surface and / or the outer surface of the window can have a predetermined curvature in a first direction, wherein the first direction corresponds to the scanning direction of the lidar. For example, as shown in Figures 7A-7C The lidar can have a horizontal scanning direction (l-axis direction shown in the reference coordinate system mnl), and correspondingly, each point on the inner surface 63a and / or the outer surface 63b of the window 63 can be set to have curvature in at least the plane direction formed by the normal vector of each point and the horizontal vector j (which can be referred to as the first direction), and the horizontal vector j can be on the ml plane shown in the reference coordinate system mnl.

[0056] In this embodiment, one or both of the inner surface 63a or the outer surface 63b of the window 63 can be set as the surface as described above. For example, Figure 7A It is shown that both the inner surface 63a and the outer surface 63b of the window 63 are set to have curvature in at least the first direction on each point thereon. Figure 7B It is shown that only the outer surface 63b of the window 63 is set to have curvature in at least the first direction on each point thereon. Figure 7C It is shown that only the inner surface 63a of the window 63 is set to have curvature in at least the first direction on each point thereon. In the case where only one of the inner surface 63a and the outer surface 63b is set to have curvature in at least the first direction, the other one of the inner surface 63a and the outer surface 63b can be set to other suitable conditions, for example, as an example but not limitation, can be set as Figure 7B the inner surface 63a (as shown in Figure 7C the outer surface 63b (as shown in

[0057] In addition, as an example, Figures 7A-7CThe illustration shows a window 63 with its inner surface 63a and / or outer surface 63b protruding outwards (towards the lidar). However, other embodiments of the present invention may include a window 63 with its inner surface 63a and / or outer surface 63b protruding inwards (towards the lidar). Accordingly, when the inner surface 63a and / or outer surface 63b of the window 63 protrudes inwards, the inner surface 63a and / or outer surface 63b of the window 63 may be configured as continuous surfaces, and each point on the continuous surface may have curvature at least in a first direction.

[0058] return Figure 6A When points on the inner surface 63a and / or outer surface 63b of window 63 have curvature in the first direction, due to the small size of the emitted light spot, the curvature of window 63 has little effect on the divergence angle of the light spot. The emitted light 62a can be directly transmitted through window 63 parallel or nearly parallel, and after being reflected by target 64, it forms echo light 62b. After being transmitted through window 63, echo light 62b is deflected by scanning device 62 and can be received and detected by transceiver module 61. Due to the reflectivity of window 63, stray emitted light 62c reflected by window 63 is reflected by scanning device 62 and transmitted through window 63 to target 65. Since the reflection point of stray emitted light 62c on window 63 has curvature in the first direction, stray emitted light 62c is a light that converges first and then diverges. Therefore, the intensity of stray emitted light 62c projected onto target 65 is relatively small (compared to...). Figure 5 Compared to the stray emitted light formed by the mid-plane view window, the energy projected onto the target 65 decreases as the target 65 becomes farther away. Consequently, the intensity of the stray echo light (not shown in the figure) formed by the reflection of the stray emitted light from the target 65 is also smaller.

[0059] Similarly, combined Figure 6B As shown, stray echo light 62c from a relatively long distance from target 65 is transmitted almost parallel through radar window 63. The stray echo light 62c is first reflected once by scanning device 62 before reaching window 63. Because the points on window 63 have curvature in the first direction, the stray echo light 62c reflected from window 63 will first converge and then diverge before reaching transceiver module 61. Therefore, the spot of stray echo light 62c received at transceiver module 61 will also be diffused in the first direction. Since the detector size is fixed, the intensity of the divergent stray echo light 62c that ultimately enters the detector is relatively small, thus greatly reducing and suppressing noise caused by secondary reflection from window 63.

[0060] The divergence angle of the stray echo 62c is related to the curvature of the window 63; that is, the greater the curvature, the greater the divergence angle. Excessive curvature leads to a larger divergence angle of the emitted light spot, thus reducing the radar's rangefinding capability. Conversely, insufficient curvature makes the window nearly flat, resulting in inadequate divergence of stray light caused by secondary reflections, thus failing to effectively suppress noise. Therefore, in one embodiment of this invention, the radius of curvature of each point on the window 63 in the first direction is set within the range of 50mm to 600mm, 100mm to 500mm, and 150mm to 400mm (including the numerical endpoints). Furthermore, in embodiments of this invention, the curvature of each point on the surface of the window 63 in the first direction can be the same or different.

[0061] The window 63 of this invention allows the stray emitted light 62c formed by the reflection of the emitted light 62a to be projected onto the target 65 in a divergent manner. It also allows the stray echo light 62c reflected by the target 65 to be incident on the detector in a divergent manner, thereby achieving attenuation of stray echo light. Therefore, when this window 63 is applied to lidar, it can effectively overcome noise problems, effectively suppress crosstalk in lidar, and improve the signal-to-noise ratio.

[0062] Considering that the window 63 needs to improve transmittance and reduce reflectance, and taking into account other mechanical properties, the material of the window 63 may include resin or glass. In a specific embodiment, the material of the window 63 may include polycarbonate. Polycarbonate has good mechanical properties, high plasticity, high impact resistance, low density, and low cost. Glass has a wide range of applications in industrial products and has better reliability and lower reflectance. In addition, the inner surface 63a and / or the outer surface 63b of the window 63 may be provided with an anti-reflection coating to improve the transmittance of the window 63 to the light beam and reduce the intensity of the light beam reflected by the window 63.

[0063] As described above, at least one of the inner surface 63a and the outer surface 63b of the window 63 according to an embodiment of the present invention can be configured as a continuous surface with a predetermined curvature at each point on its surface in a first direction, thereby attenuating stray light. As an example, Figures 6A-6B Only the light path formed after reflection from the inner surface 63a of the window 63 is shown. It is understood that when the outer surface 63b of the window 63 is also configured as the surface described above in this invention, the light path emitted from the outer surface 63b is similar, and it also has the technical effect of attenuating stray light to reduce or remove noise on the point cloud.

[0064] Example 2. Points on the window surface have a predetermined curvature in a second direction

[0065] In some other embodiments, points on the inner and / or outer surfaces of the window may have a predetermined curvature in a second direction different from the first direction, wherein the first direction corresponds to the scanning direction of the lidar. For example, as in combination Figures 8A-8C As shown, the lidar can have a horizontal scanning direction (the l-axis direction shown in the reference coordinate system mnl). Correspondingly, each point on the inner surface 83a and / or outer surface 83b of the window 83 can be configured to have curvature in the plane direction formed by the normal vector of each point and the vertical vector k (this plane direction can be called the second direction). The vertical vector k can be located on the nm plane shown in the reference coordinate system mnl.

[0066] In this embodiment, one or both of the inner surface 83a or the outer surface 83b of the window 83 can be configured as the surfaces described above. For example, Figure 8A It is shown that the inner surface 83a and the outer surface 83b of the window 83 are both configured such that each point thereon has curvature at least in the second direction. Figure 8B It is shown that only the outer surface 83b of the window 83 is configured such that each point thereon has curvature at least in the second direction. Figure 8C It is shown that only the inner surface 83a of the viewport 83 is configured such that each point thereon has curvature at least in the second direction. While only one of the inner surface 83a and the outer surface 83b is configured to have curvature at least in the second direction, the other of the inner surface 83a and the outer surface 83b can be configured in other suitable ways; for example, by way of example and not limitation, it can be configured as follows: Figure 8B (inner surface 83a) and Figure 8C The plane shown is (outer surface 83b).

[0067] Furthermore, as an example, Figures 8A-8C The illustration shows a window 83 with its inner surface 83a and / or outer surface 83b protruding outwards (towards the lidar). However, other embodiments of the present invention may include a window 83 with its inner surface 83a and / or outer surface 83b protruding inwards (towards the lidar). Accordingly, when the inner surface 83a and / or outer surface 83b of the window 83 protrudes inwards, the inner surface 83a and / or outer surface 83b of the window 83 may be configured as continuous surfaces, and each point on the continuous surface may have curvature at least in a second direction.

[0068] and Figures 7A-7C Similarly, when each point on window 83 has curvature in the second direction, it can disperse stray light reflected by window 83. More specifically, window 83 can diffuse stray light in the second direction, thereby greatly reducing the intensity of stray emitted light reaching the target and stray echo light reflected back to the detector from the target, thus greatly reducing and suppressing noise caused by secondary reflection of window 83.

[0069] In addition, similarly, in order to balance the far vision ability and the noise suppression, the radius of curvature of each point on the surface of the window 83 in the second direction is set in the range of 50mm-600mm, in the range of 100mm-500mm, or in the range of 150mm-400mm (including the numerical end points). In addition, in the embodiments of the present application, the curvature of each point on the surface of the window 83 in the second direction can be the same or different.

[0070] Considering that the window 83 needs to improve the transmittance and reduce the reflectivity, and comprehensively considering other mechanical properties, the material of the window 83 can include resin or glass. In specific embodiments, the material of the window 83 can include polycarbonate. The polycarbonate material has good mechanical properties, strong plasticity, strong impact resistance, low density, low cost and other characteristics. Glass has a wide range of applications in industrial products, and has better reliability and lower reflectivity. In addition, the inner surface 83a and / or the outer surface 83b of the window 83 can be provided with an anti-reflection film to improve the transmittance of the window 83 to the light beam and reduce the intensity of the light beam reflected by the window 83.

[0071] Example 3. Points on the window surface have respective predetermined curvatures in a first direction and in a second direction

[0072] In yet other embodiments, each point on the inner surface and / or the outer surface of the window can have a corresponding predetermined curvature in both the first direction and the second direction, wherein the first direction corresponds to the scanning direction of the lidar, and the second direction is different from the first direction. For example, in combination with FIG. 9A, Figures 9A-9C As shown, the lidar can have a horizontal scanning direction (the l-axis direction shown in the reference coordinate system mnl), and correspondingly, each point on the inner surface 93a and / or the outer surface 93b of the window 93 can have a corresponding curvature in both the first direction and the second direction, wherein the first direction is the direction of the plane formed by the normal vector of each point on the inner surface 93a and / or the outer surface 93b of the window 93 and the horizontal vector j, which can be on the ml plane shown in the reference coordinate system mnl; the second direction is the direction of the plane formed by the normal vector of each point and the vertical vector k, which can be on the nm plane shown in the reference coordinate system mnl.

[0073] In this embodiment, one or both of the inner surface 93a or the outer surface 93b of the window 93 can be set as the surface as described above. For example, Figure 9A As shown, both the inner surface 93a and the outer surface 93b of the window 93 are set as surfaces on which each point has a corresponding curvature in both the first direction and the second direction. Figure 9B As shown, only the outer surface 93b of the window 93 is set as a surface on which each point has a corresponding curvature in both the first direction and the second direction. Figure 9CIt is shown that the inner surface 93a of the window 93 is provided as a continuous surface on which each point has a respective curvature in the first direction and the second direction. When only one of the inner surface 93a and the outer surface 93b is provided as a continuous surface on which each point has a respective curvature in the first direction and the second direction, the other one of the inner surface 93a and the outer surface 93b can be provided as other suitable cases, for example, as an example but not limitation, can be provided as a plane as shown in Figure 9B the inner surface 93a (inner surface 93a) and Figure 9C the outer surface 93b (outer surface 93b).

[0074] In addition, as an example, Figures 9A-9C It is shown that the inner surface 93a and / or the outer surface 93b of the window 93 is / are outwardly convex (outwardly to the outside of the lidar). However, other embodiments of the present application can include a window 93a whose inner surface 93a and / or outer surface 93b is / are inwardly convex (inwardly to the inside of the lidar). Correspondingly, when the inner surface 93a and / or the outer surface 93b of the window 93a is / are inwardly convex, the inner surface 93a and / or the outer surface 93b of the window 93a can be provided as a continuous surface, and each point on the continuous surface has a respective curvature in the first direction and the second direction, respectively.

[0075] Similar to Figures 7A-7C and Figures 8A-8C , when each point on the window 93 has a respective curvature in the first direction and the second direction, the stray light reflected through the window 93 can be dispersed, and more specifically, the window 93 can disperse the stray light in the first direction and the second direction, greatly reducing the intensity of the stray emission light reaching the target and the stray echo light reflected back to the detector from the target, and further greatly reducing and suppressing the noise caused by the secondary reflection of the window 93.

[0076] In addition, similarly, in order to balance the long-distance measurement capability and the noise suppression, the radius of curvature of each point on the surface of the window 93 in the first direction is respectively set in the range of 50mm-600mm, in the range of 100mm-500mm, or in the range of 150mm-400mm (including the numerical endpoints), and the radius of curvature of each point on the surface of the window 93 in the second direction is also respectively set in the range of 50mm-600mm, in the range of 100mm-500mm, or in the range of 150mm-400mm (including the numerical endpoints). In addition, in the embodiments of the present application, the curvatures of each point on the surface of the window 93 in the first direction can be the same or different; the curvatures of each point on the surface of the window 93 in the second direction can be the same or different.

[0077] In view of the need for the window 93 to have increased transmittance and decreased reflectance, and in view of other mechanical properties, the material of the window 93 can include resin or glass. In specific embodiments, the material of the window 93 can include poly carbonate. Poly carbonate material has good mechanical properties, is strong in plasticity, strong in impact resistance, low in density, and low in cost. Glass has a wide range of applications in industrial products, and has better reliability and lower reflectance. In addition, the inner surface 93a and / or the outer surface 93b of the window 93 can be provided with an anti-reflection film to improve the transmittance of the window 93 for the light beam and reduce the intensity of the light beam reflected by the window 93.

[0078] It should be understood that the above horizontal and vertical directions are relative to the case where the lidar has a horizontal scanning direction, and thus are merely exemplary embodiments for the convenience of description. In the case where the lidar has other scanning directions, the directions in which the points on the window surface have curvature described above can also be adjusted accordingly.

[0079] The above shows three embodiments of the window of the utility model. Further, the window of the utility model can design the directions in which the points on the window surface have curvature according to the energy distribution of the light spot. For example, the light spot is concentrated in the horizontal and / or vertical direction after being scanned by the scanning device, and thus the settings of the above embodiments can be selected accordingly. In addition, in some other embodiments, the light spot can be concentrated in one or more other directions after being scanned by the scanning device, and thus the directions in which the points on the window surface have curvature can be set accordingly. However, it should be understood that the utility model can have a predetermined curvature in one or more other directions different from the above horizontal and vertical directions, and the utility model can also have a predetermined curvature in one or more directions not corresponding to the directions in which the energy is concentrated.

[0080] The utility model also provides a kind of lidar, for example Figures 6A-6B The lidar shown in the drawing. The lidar of the utility model can include: transceiver module 61, transceiver module 61 is configured to generate emission light and receive echo light;The window of any one of the above window embodiments;And scanning device 62, scanning device 62 is configured to deflect the emission light from transceiver module 61 to the window, wherein the emission light is emitted after transmitting through the window and forms echo light after being reflected by target, scanning device 62 is also configured to deflect the echo light transmitting through the window to transceiver module 61, for transceiver module 61 receives and detects echo light. In some embodiments of the utility model, scanning device 62 can include rotating mirror or galvanometer.

[0081] The new type of window can be applied to the coaxial or paraxial transceiving laser radar. Therefore, in some embodiments, the part of the light path of the emitted light generated by the transceiving module of the laser radar can be a coaxial light path with the part of the light path of the echo light received by the transceiving module. In some embodiments, the part of the light path of the emitted light generated by the transceiving module of the laser radar can be a paraxial light path with the part of the light path of the echo light received by the transceiving module.

[0082] It should be understood that the descriptions of positions and directions in this specification are made in conjunction with the specific embodiments shown in the drawings, and are therefore a relative position description. In other embodiments where the placement direction of the device, apparatus is opposite or different from the direction shown in the drawings, these position descriptions can be changed accordingly.

[0083] Therefore, without departing from the spirit and main points of the present application, those skilled in the art can make appropriate modifications and adjustments to the above specifically described embodiments. Therefore, it is intended that the claimed subject matter not be limited to the specific examples disclosed, but that all implementations falling within the scope of the appended claims and their equivalents be included.

Claims

1. A window for a lidar, the lidar comprising: a transceiver module configured to generate a transmitted light and receive a returned light; and a scanning device configured to deflect the transmitted light from the transceiver module to the window, wherein the transmitted light transmits through the window and exits and forms the returned light after being reflected by a target, the scanning device is further configured to deflect the returned light transmitting through the window to the transceiver module for the transceiver module to receive and detect the returned light. Characterized in that, an inner surface and / or an outer surface of the window is a continuous surface, and each point on the continuous surface has a curvature in at least one direction respectively.

2. The window of claim 1, wherein The point on the continuous surface is configured to at least one of the following: has a predetermined curvature in a first direction, the first direction corresponding to a scanning direction of the lidar; has a predetermined curvature in a second direction different from the first direction, the first direction corresponding to the scanning direction of the lidar; or has a corresponding predetermined curvature in the first direction and the second direction, the first direction corresponding to the scanning direction of the lidar, and the second direction being different from the first direction.

3. The window of claim 1, wherein The curvature radius of each point on the continuous surface in the at least one direction is the same or different.

4. The window of claim 1, wherein The curvature radius of each point on the continuous surface in the at least one direction is in a range of 150mm to 400mm.

5. The window of any of claims 1-4, wherein, The inner surface and / or the outer surface of the window is provided with an anti-reflection film.

6. The window of any of claims 1-4, wherein, The continuous surface is configured to be convex towards an external space of the lidar, or convex towards an internal space of the lidar.

7. The window of any of claims 1-4, wherein, The material of the window comprises resin or glass.

8. A lidar, comprising: The lidar comprises: a transceiver module configured to generate a transmitted light and receive a returned light; the window according to any one of claims 1-7; and a scanning device configured to deflect the transmitted light from the transceiver module to the window, wherein the transmitted light transmits through the window and exits and forms the returned light after being reflected by a target, the scanning device is further configured to deflect the returned light transmitting through the window to the transceiver module for the transceiver module to receive and detect the returned light.

9. The lidar of claim 8, wherein, A part of the light path of the transmitted light generated by the transceiver module is coaxial with a part of the light path of the returned light received by the transceiver module.

10. The lidar of claim 8, wherein, The scanning device comprises a rotating mirror or a galvanometer.

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