Laser receiving unit, laser receiving module, laser radar and intelligent equipment

Abstract

The embodiment of the present application discloses a laser receiving unit. The laser receiving unit includes a laser receiver and a light adjusting component. The light adjusting component includes an optical transmission part and an optical attenuation part. The optical transmission part performs total internal reflection processing on the echo signal, and then transmits the echo signal processed by total internal reflection to the laser receiving surface of the laser receiver. The optical attenuation part performs intensity attenuation processing on the echo signal, and then transmits the echo signal processed by intensity attenuation to the laser receiving surface of the laser receiver. The present application sets an optical transmission part and utilizes the performance of the optical transmission part to reflect the echo signal reflected by an object at a relatively close distance back to the laser receiving surface of the laser receiver in the form of total internal reflection, thereby effectively expanding the signal receiving range of the laser receiver. The present application performs attenuation processing on the echo signal reflected by objects at medium and short distances, reduces the intensity of the echo signal incident on the laser receiving surface, and avoids saturation of the laser receiver.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser radar technology, and specifically to a laser receiving unit, a laser receiving module, a laser radar and an intelligent device. Background Art

[0002] Lidar (Light Detection and Ranging) is used to detect targets. It consists of a laser transmitter and a laser receiver. Typically, the optical axis of the laser transmitter and the laser receiver, as provided by related technologies, are separated by a certain distance. As a result, the closer the target is to the lidar, the less likely the laser receiver is to receive the echo signal reflected from the close-range target. This results in a narrow signal reception range for the laser receiver, making it difficult for the lidar to effectively detect close-range targets. Summary of the Invention

[0003] In order to solve the above technical problems, the embodiments of the present application provide a laser receiving unit, a laser receiving module, a laser radar and an intelligent device to improve the technical problem of the narrow signal receiving range of the laser receiver provided by the related technology.

[0004] In a first aspect, an embodiment of the present application provides a laser receiving unit, comprising a laser receiver and a light adjustment component, wherein the light adjustment component comprises an optical transmission portion and an optical attenuation portion; the optical transmission portion is arranged around the laser receiver, and the optical transmission portion is configured to perform total internal reflection processing on the echo signal from a first position range, and then transmit the echo signal subjected to the total internal reflection processing to the laser receiving surface of the laser receiver; the optical attenuation portion is arranged on the laser receiving surface of the laser receiver, and the optical attenuation portion is configured to perform intensity attenuation processing on the echo signal from a second position range, and then transmit the echo signal subjected to the intensity attenuation processing to the laser receiving surface of the laser receiver.

[0005] Optionally, the orthographic projection of the optical transmission portion on the laser receiving surface is located on a side of the light adjusting component away from the laser emitter.

[0006] Optionally, the optical transmission part includes a first upper surface and a first lower surface arranged opposite to each other, the first upper surface is configured to receive an echo signal, wherein the first upper surface is provided with a first optical film, and the first lower surface is provided with a second optical film, the reflectivity of the first optical film is less than a first preset threshold, the reflectivity of the second optical film is greater than a second preset threshold, and the second preset threshold is greater than the first preset threshold.

[0007] Optionally, the orthographic projection of the optical attenuation portion on the laser receiving surface at least partially overlaps with the area where the laser receiver is located; or,

[0008] The orthographic projection of the optical attenuation portion on the laser receiving surface covers the area where the laser receiver is located.

[0009] Optionally, the optical attenuation portion includes a second upper surface and a second lower surface arranged opposite to each other, the second upper surface being configured to receive an echo signal, wherein the second upper surface is provided with a third optical film, and the second lower surface is provided with a fourth optical film, the reflectivity of the third optical film is greater than a third preset threshold but less than a fourth preset threshold, the reflectivity of the fourth optical film is less than a fifth preset threshold, and the fifth preset threshold is less than the third preset threshold.

[0010] Optionally, the light adjusting member is a curved prism, and the curved prism includes the optical transmission part and the optical attenuation part. The optical transmission part is arranged around the laser receiver, and the optical attenuation part is arranged on the laser receiving surface of the laser receiver.

[0011] Optionally, an incident angle of an echo signal from any incident position of the optical transmission portion in the optical transmission portion is greater than a critical angle.

[0012] Optionally, the light adjusting component is an arrayed waveguide structure, which includes the optical transmission part and the optical attenuation part. The optical transmission part is arranged around the laser receiver, and the optical attenuation part is arranged on the laser receiving surface of the laser receiver.

[0013] Optionally, at least one first reflecting surface is provided in the optical transmission portion, and the at least one first reflecting surface is sequentially and obliquely arranged in the optical transmission portion along a light propagation direction of the echo signal in the optical transmission portion, and a reflectivity of the first reflecting surface is greater than a sixth preset threshold;

[0014] A plurality of second reflection surfaces are provided in the optical attenuation portion. Along the light propagation direction of the echo signal in the optical attenuation portion, the plurality of second reflection surfaces are arranged in sequence and tilted behind the first reflection surface. The reflectivity of the second reflection surface is less than or equal to the reflectivity of the first reflection surface.

[0015] Optionally, the arrayed waveguide structure includes a waveguide upper surface and a waveguide lower surface arranged opposite to each other, the waveguide upper surface is configured to receive an echo signal, and along the propagation direction of the light, the first reflecting surface is arranged at an acute angle to the waveguide upper surface, and / or the second reflecting surface is arranged at an acute angle to the waveguide upper surface, and the acute angle is [ , ] any value between ].

[0016] Optionally, in the arrayed waveguide structure, the mirror distances between two adjacent second reflection surfaces are equal, and the projection length of the second reflection surface on the upper surface of the waveguide is equal to the mirror distance; or, in the arrayed waveguide structure, the mirror distances between two adjacent second reflection surfaces are equal, and the projection length of the second reflection surface on the upper surface of the waveguide is equal to the target distance, and the target distance is the sum of the mirror distance and a preset margin length.

[0017] Optionally, along the propagation direction of the light, the reflectivity of the last second reflective surface among the plurality of second reflective surfaces is greater than a seventh preset threshold, and the seventh preset threshold is greater than the sixth preset threshold.

[0018] Optionally, the light adjusting member is a grating waveguide structure, the grating waveguide structure includes an optical transmission portion and an optical attenuation portion, the optical transmission portion is arranged around the laser receiver, and the optical attenuation portion is arranged on the laser receiving surface of the laser receiver;

[0019] The optical transmission portion includes a grating portion and a first waveguide portion. The grating portion is arranged around the laser receiver and located above the first waveguide portion. The grating portion is configured to change the direction of the echo signal from a first position range incident on the first waveguide portion, so that the echo signal undergoes total internal reflection in the first waveguide portion, and the diffraction angle of the grating portion is greater than the critical angle of the first waveguide portion.

[0020] In a second aspect, an embodiment of the present application provides a laser receiving module, comprising at least one laser receiving array, wherein the laser receiving array comprises a plurality of the aforementioned laser receiving units and a laser receiving board, wherein the plurality of laser receiving units are arranged on the laser receiving board in a matrix arrangement.

[0021] In a third aspect, an embodiment of the present application provides a laser radar, including:

[0022] The above-mentioned laser receiving module;

[0023] The laser emission module includes at least one laser emission array, which includes multiple laser emitters and a laser emission board. The multiple laser emitters are arranged on the laser emission board in a matrix arrangement. One laser emitter corresponds to one laser receiver, wherein the optical axis of the laser emitter is separated from the optical axis of the laser receiver by a preset distance.

[0024] In a fourth aspect, an embodiment of the present application provides a smart device comprising the above-mentioned laser radar.

[0025] The beneficial effects of the embodiments of the present application are as follows: by providing an optical transmission unit and utilizing the performance of the optical transmission unit, the embodiments of the present application reflect the echo signal reflected by a relatively close object back to the laser receiving surface of the laser receiver in the form of total internal reflection, thereby effectively expanding the signal reception range of the laser receiver and facilitating more effective detection of the distances of different objects at close range. The embodiments of the present application attenuate the echo signal reflected by objects at medium and short distances, reducing the intensity of the echo signal incident on the laser receiving surface at this time, avoiding saturation of the laser receiver, and facilitating improved discrimination of objects at medium and short distances, thereby improving the detection reliability and accuracy of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0027] Figure 1 A schematic diagram of the structure of a laser radar provided for related technologies;

[0028] Figure 2 A schematic structural diagram of a laser receiving unit provided in an embodiment of the present application;

[0029] Figure 3 Based on Figure 1 The schematic diagram of the laser radar receiving the echo signals at relatively close distance and medium-short distance shown;

[0030] Figure 4 A schematic diagram of a laser radar provided in an embodiment of the present application receiving echo signals at relatively close and medium distances;

[0031] Figure 5 This is a schematic structural diagram of a laser receiving unit provided in yet another embodiment of the present application, wherein the light adjustment member is a curved prism;

[0032] Figure 6 This is a schematic structural diagram of a laser receiving unit provided in yet another embodiment of the present application, wherein the light adjustment component is an arrayed waveguide structure;

[0033] Figure 7 This is a schematic structural diagram of a laser receiving unit provided in yet another embodiment of the present application, wherein the light adjustment component is an arrayed waveguide structure;

[0034] Figure 8 This is a schematic structural diagram of a laser receiving unit provided in yet another embodiment of the present application, wherein the light adjustment component is an arrayed waveguide structure;

[0035] Figure 9 This is a schematic structural diagram of a laser receiving unit provided in yet another embodiment of the present application, wherein the light adjustment component is an arrayed waveguide structure;

[0036] Figures 10a to 10e Schematic diagram of the structures of various gratings provided in the embodiments of this application;

[0037] Figure 11 This is a schematic structural diagram of a laser receiving unit provided by yet another embodiment of the present application, wherein the light adjustment component is a grating waveguide structure;

[0038] Figure 12 A schematic diagram of how echo energy varies with distance provided in an embodiment of the present application;

[0039] Figure 13 A schematic structural diagram of a laser receiving module provided in an embodiment of the present application;

[0040] Figure 14 An equivalent schematic diagram of a laser receiving module provided in an embodiment of the present application receiving echo signals from different independent channels;

[0041] Figure 15 An equivalent schematic diagram of a laser receiving module receiving echo signals from different independent channels provided in another embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as being "electrically connected" to another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "upper", "lower", "inner", "outer", "bottom" and the like used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0043] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items. In addition, the technical features involved in the different embodiments of this application described below may be combined with each other as long as they do not conflict with each other.

[0044] Many application scenarios have certain standards and requirements for the detection range of LiDAR. LiDAR can be used not only to detect targets at long distances, but also to detect targets at close ranges. In theory, the laser signal emitted by the laser transmitter can be received by the laser receiver, that is, the laser signal emitted by the laser transmitter corresponds to the laser signal received by the laser receiver. Due to the system design of LiDAR, the transmission and reception of LiDAR are designed to be off-axis. In off-axis radar, the following problems are prone to occur:

[0045] The farther the distance between the target object and the laser radar, the easier it is for the echo signal reflected by the distant target object to fall on the laser receiving surface of the laser receiver. The closer the distance between the target object and the laser radar, the easier it is for the echo signal reflected by the close target object to deviate from the laser receiving surface of the laser receiver.

[0046] As the distance between a relatively close target and the LiDAR decreases, for example, a 5-meter target gradually approaches the LiDAR, the energy of the echo signal received by the laser receiver's laser receiving surface gradually weakens until the echo signal moves beyond the laser receiver's laser receiving surface, making the LiDAR unable to reliably detect the close target. It is understood that targets within 5 meters are considered relatively close targets relative to the LiDAR.

[0047] Furthermore, when a medium-to-close target approaches the lidar, there may be a period of time during which the reflected echo signal does not deviate from the laser receiver's laser receiving surface. However, the energy of the echo signal at this time is very strong. A highly sensitive lidar has a signal strength range that allows for accurate measurement. When the energy of the echo signal exceeds this range, the laser receiver enters saturation. When the laser receiver is near or at saturation, its response no longer follows a linear relationship with the input echo signal, but rather a nonlinear one. This nonlinear response weakens the differences between echo signals, resulting in a decrease in the lidar's ability to distinguish between different echo signals. It is understandable that targets within 5 to 10 meters are considered medium-to-close range targets relative to the lidar.

[0048] See also Figure 1 The laser radar includes a laser transmitter 11 and a laser receiver 12. The laser transmitter 11 is provided with a transmitting lens 13, and the laser receiver 12 is provided with a receiving lens 14. The first optical axis O1 of the transmitting lens 13 and the second optical axis O2 of the receiving lens 14 are separated by a preset distance D.

[0049] The laser radar is used to detect the surrounding environment. The surrounding environment is provided with a first object 15, a second object 16 and a third object 17. The distance between the first object 15 and the laser radar is greater than the distance between the second object 16. Relative to the laser radar, the distance between the first object 15 and the laser radar is 100 meters, the distance between the second object 16 and the laser radar is 30 meters, and the distance between the third object 17 and the laser radar is 50 meters.

[0050] The laser transmitter 11 transmits a first laser signal 111 , a second laser signal 112 and a third laser signal 113 . The first laser signal 111 is incident on the first object 15 , is reflected by the first object 15 to form a first echo signal 151 , and the first echo signal 151 is incident back on the laser receiving surface of the laser receiver 12 .

[0051] The second laser signal 112 is incident on the second object 16 and reflected by the second object 16 to form a second echo signal 161. Since the second object 16 is a target at a relatively close distance, the second echo signal 161 does not enter the laser receiving surface of the laser receiver 12, but moves out of the laser receiving surface of the laser receiver 12, resulting in the laser radar not detecting the second object 16.

[0052] The third laser signal 113 is incident on the third object 17 and is reflected by the third object 17 to form a third echo signal 171. Since the third object 17 is a medium-to-short distance target, the energy of the third echo signal 171 is relatively large. Although the third echo signal 171 can be incident back on the laser receiving surface of the laser receiver 12, the laser receiver is in a saturated state and cannot accurately detect the distance between the third object 17 and the laser radar.

[0053] In the process of implementing the embodiments of the present application, the inventors discovered the following related technologies for overcoming the problem of echo signals at close distances deviating from the laser receiving surface, specifically as follows:

[0054] ① Related technologies place a prism on the transmitting or receiving lens side. The prism can deflect the outgoing laser signal at a certain angle or refract the echo signal within a certain distance range to the laser receiving surface of the laser receiver. The disadvantage of this approach is that the prism assembly requirements are high, and the process and processing costs are high.

[0055] ② Related technologies place scatterers on the receiving side to scatter short-range echo signals back to the laser receiving surface of the laser receiver. The disadvantage of this approach is that the scatterers have a large scattering angle, which can easily scatter scattered light into other laser receiving channels, causing laser crosstalk and adding significant crosstalk noise to the laser point cloud.

[0056] The embodiment of the present application reflects the echo signal reflected by a relatively close object back to the laser receiving surface of the laser receiver in the form of total internal reflection. This effectively expands the signal reception range of the laser receiver and facilitates more effective detection of the distances of different objects at close distances. At the same time, the embodiment of the present application attenuates the echo signal reflected by objects at medium and short distances, reducing the intensity of the echo signal incident on the laser receiving surface at this time, avoiding saturation of the laser receiver, and facilitating improved discrimination of medium and short distance objects, thereby improving the detection reliability and accuracy of the lidar.

[0057] Hereinafter, the embodiment of the present application provides a laser receiving unit. Figure 2 The laser receiving unit 200 includes a laser receiver 300 and a light adjusting component 400 .

[0058] The laser receiver 300 is provided with a laser receiving surface for receiving the echo signal reflected by the object. The laser receiver 300 includes a photodiode receiver, an avalanche photodiode receiver, a single photon avalanche photodiode receiver, a silicon photomultiplier diode receiver, a quadrant detector, a focal plane array detector, etc.

[0059] The light adjusting member 400 includes an optical transmission portion 41 and an optical attenuation portion 42 . The optical transmission portion 41 and the optical attenuation portion 42 may be integrally formed or may be two separate optical components.

[0060] The optical transmission part 41 is disposed around the laser receiver 300. In some embodiments, the orthographic projection of the optical transmission part 41 on the laser receiving surface is located on a side of the light adjusting member 400 away from the laser emitter.

[0061] Please combine Figure 2 The orthographic projection of the optical transmission unit 41 on the laser receiving surface 31 contacts the area where the laser receiver 300 is located. The echo signal that has just deviated from the laser receiving surface 31 can be incident on the optical transmission unit 41. The optical transmission unit 41 can perform total internal reflection processing on the echo signal and then transmit the echo signal after total internal reflection processing to the laser receiving surface of the laser receiver 300. In this way, the embodiment of the present application does not need to design and enlarge the receiving surface of the laser receiver, and can transmit the light spot at medium and short distances to the receiver, thereby saving design costs.

[0062] The optical transmission unit 41 performs total internal reflection on the echo signal from the first position range and then transmits the processed echo signal to the laser receiving surface of the laser receiver 300. Total internal reflection means that the echo signal incident on the optical transmission unit 41 is reflected within the optical transmission unit 41 and does not transmit outside the optical transmission unit 41.

[0063] The first position range is the range within which the distance from the laser radar is less than a first preset distance threshold. The first preset distance threshold is customized by the designer based on the radar's detection requirements. For example, if the first preset distance threshold is 5 meters and the first position range is 0 to 5 meters, the optical transmission unit 41 can perform total internal reflection processing on echo signals within 5 meters.

[0064] In some embodiments, the optical transmission portion 41 is disposed at a first preset position, and is capable of performing total internal reflection processing on the echo signal from within the first position range, and then transmitting the echo signal processed by total internal reflection processing to the laser receiving surface of the laser receiver 300 .

[0065] The first preset position is determined by the designer using a laser optical path simulation tool, combining the positions of the laser emitter and the laser receiver. Laser optical path simulation tools include Ansys Zemax OpticStudio, LightTools, ASAP, and the SeeLight optical system virtual simulation experiment platform. Ansys Zemax OpticStudio uses advanced ray tracing algorithms to simulate the behavior of light in optical systems, and can analyze and optimize the performance of optical components such as lenses and reflectors. LightTools can create, observe, modify, and analyze optical systems through drawing graphics, and can directly describe components such as light sources, lenses, reflectors, and optical paths in optical systems. ASAP is based on non-sequential ray tracing and can simulate the performance of optical systems in 3D space. It can simulate and analyze almost any geometric shape and various optical phenomena such as scattering and diffraction. The SeeLight optical system virtual simulation experiment platform has 72 basic optical component models and 8 fiber laser component models, supporting the design and simulation of a variety of optical components and complex optical paths.

[0066] For example, if the offset distance between the optical axis of the laser transmitter and the optical axis of the laser receiver is d1, and the echo signal from within a range of 5 meters needs to be processed by total internal reflection, the embodiment of the present application can obtain the position relative to the laser receiver 300 through simulation calculation, and the first preset position is (x1, y1).

[0067] If the offset distance between the optical axis of the laser transmitter and the optical axis of the laser receiver is d2, and the echo signal from within a range of 5 meters needs to be processed by total internal reflection, the embodiment of the present application can obtain the position relative to the laser receiver 300 through simulation calculation, and the first preset position is (x2, y2).

[0068] If the offset distance between the optical axis of the laser transmitter and the optical axis of the laser receiver is d3, and the echo signal from within a range of 4 meters needs to be processed by total internal reflection, the embodiment of the present application can obtain the position relative to the laser receiver 300 through simulation calculation, and the first preset position is (x3, y3).

[0069] It is understandable that those skilled in the art can combine the contents disclosed in the embodiments of the present application with the characteristics of their own products to perform simulation operations on the position and structural characteristics of the optical transmission part 41, and ultimately be able to find a first preset position with the following functions: performing total internal reflection processing on the echo signal from within the first position range.

[0070] The embodiment of the present application sets up an optical transmission part 41 and utilizes the performance of the optical transmission part 41 to reflect the echo signal reflected by an object at a relatively close distance back to the laser receiving surface of the laser receiver in the form of total internal reflection. This can effectively expand the signal receiving range of the laser receiver, which is conducive to more effective detection of the distance of different objects at close distances.

[0071] The optical attenuation unit 42 is disposed on the laser receiving surface of the laser receiver 300 . The optical attenuation unit is used to perform intensity attenuation processing on the echo signal from the second position range and then transmit the intensity attenuated echo signal to the laser receiving surface of the laser receiver 300 .

[0072] The intensity attenuation process refers to moderately attenuating the intensity of the echo signal incident on the optical attenuation unit 42 to prevent the intensity of the echo signal incident on the laser receiving surface from being too high and causing the laser receiver to enter a saturation state.

[0073] The second position range is defined as the range within which the distance from the laser radar is greater than or equal to the second preset distance threshold and less than the third preset distance threshold. The second and third preset distance thresholds are defined by the designer based on engineering experience. For example, if the second preset distance threshold is 5 meters and the third preset distance threshold is 10 meters, the second position range is between 5 and 10 meters. In other words, the optical attenuation unit 42 is configured to attenuate the intensity of echo signals within the range of 5 to 10 meters and then transmit the attenuated echo signals to the laser receiving surface of the laser receiver 300.

[0074] In some embodiments, the optical attenuation portion 42 is disposed at a second preset position. The second preset position is determined by the designer through simulation using a laser light path simulation tool, combining the position of the laser emitter, the position of the laser receiver, and the position of the optical transmission portion 41 .

[0075] In some embodiments, please combine Figure 2 The orthographic projection of the optical attenuation portion 42 on the laser receiving surface at least partially overlaps the area where the laser receiver is located. The optical attenuation portion 42 can perform intensity attenuation processing on a portion of the echo signal incident on the laser receiving surface, and then transmit the intensity-attenuated echo signal to the laser receiving surface of the laser receiver 300. In this way, the embodiment of the present application does not require the design of a large-scale optical attenuation portion 42, and only needs to perform intensity attenuation processing on a portion of the echo signal incident on the laser receiving surface, thereby saving design costs and meeting the needs of some special scenarios.

[0076] In other embodiments, the optical attenuation portion 42 has an orthographic projection on the laser receiving surface covering the area where the laser receiver 300 is located. The optical attenuation portion 42 can perform intensity attenuation processing on all echo signals incident on the laser receiving surface, and then transmit the echo signals after intensity attenuation processing to the laser receiving surface of the laser receiver 300. In this way, the embodiments of the present application can ensure that saturation will not occur at any point on the laser receiving surface of the laser receiver 300.

[0077] In contrast, the embodiment of the present application sets an optical attenuation unit 42 and utilizes the characteristics of the optical attenuation unit 42 to attenuate the echo signal reflected by objects at medium and short distances, thereby reducing the intensity of the echo signal incident on the laser receiving surface at this time, avoiding saturation of the laser receiver, and helping to improve the discrimination of objects at medium and short distances, thereby improving the detection reliability and accuracy of the laser radar.

[0078] In order to elaborate on the technical effects of the laser receiving unit provided in the embodiment of the present application, the embodiment of the present application combines Figure 3 and Figure 4 This is elaborated in detail as follows:

[0079] See also Figure 3 The first echo signal 21 from a relatively close distance passes through the receiving lens 14 but does not enter the laser receiver 300. Instead, it falls next to the laser receiver 300, causing the laser receiver 300 to be unable to receive the first echo signal 21. The second echo signal 22 from a medium-short distance passes through the receiving lens 14 and directly enters the laser receiver 300. At this time, the intensity of the second echo signal 22 is too high, which can easily cause the laser receiver 300 to enter a saturated state.

[0080] See also Figure 4In the embodiment of the present application, a light adjustment component 400 is added. On the one hand, the first echo signal 21 is incident on the optical transmission part 41. The optical transmission part 41 performs total internal reflection processing on the first echo signal 21, and then transmits the echo signal after the total internal reflection processing to the laser receiving surface of the laser receiver 300. In this way, the embodiment of the present application can effectively expand the signal receiving range of the laser receiver, which is conducive to more effective detection of the distance of different objects at close range.

[0081] On the other hand, the second echo signal 22 enters the optical attenuation unit 42, and the optical attenuation unit 42 performs intensity attenuation processing on the second echo signal 22, and then transmits the echo signal after intensity attenuation processing to the laser receiving surface of the laser receiver 300. In this way, the embodiment of the present application can avoid the saturation phenomenon of the laser receiver, which is beneficial to improve the discrimination of objects at medium and short distances.

[0082] In some embodiments, see Figure 5 The optical transmission portion 41 includes a first upper surface 41a and a first lower surface 41b arranged opposite to each other. The first upper surface 41a is used to receive the echo signal. The first upper surface 41a is provided with a first optical film, and the first lower surface 41b is provided with a second optical film. The reflectivity of the first optical film is less than the first preset threshold, the reflectivity of the second optical film is greater than the second preset threshold, and the second preset threshold is greater than the first preset threshold.

[0083] The first optical film is made of a film material with low reflectivity, and the second optical film is made of a film material with high reflectivity. The materials of the first optical film and the second optical film are customized by the designer based on engineering experience.

[0084] The first optical film includes a single-layer antireflection film, a multi-layer antireflection film, a broadband antireflection film, a V-groove antireflection film, a subwavelength structure antireflection film, a zirconium oxide film layer, an aluminum oxide film layer, a calcium fluoride film layer, a barium fluoride film layer, a polymethyl methacrylate film layer, a cycloolefin polymer film layer, and the like.

[0085] The second optical thin film includes an aluminum film, a silver film, a gold film, a multilayer film based on titanium dioxide and silicon dioxide, a multilayer film based on zinc sulfide and magnesium fluoride, and the like.

[0086] The first preset threshold and the second preset threshold are customized by the designer based on engineering experience. For example, the first preset threshold is any value between 1% and 10%, and illustratively, the first preset threshold is 2%. The second preset threshold is any value between 90% and 98%, and illustratively, the second preset threshold is 95%.

[0087] In the embodiment of the present application, a film layer with a reflectivity less than a first preset threshold is selected as the first optical film, and a film layer with a reflectivity greater than a second preset threshold is selected as the second optical film. The first optical film can increase the incidence rate of the echo signal from the first position range, so that more echo signals from the first position range can be deflected to the interior of the optical transmission part 41 for total internal reflection processing. The second optical film can reduce the transmittance of the echo signal from the first position range, gather more echo signals to be deflected to the interior of the optical transmission part 41 for total internal reflection processing, thereby improving the signal reception rate of the laser receiver.

[0088] In some embodiments, please combine Figure 5 The optical attenuation portion 42 includes a second upper surface 42a and a second lower surface (not shown) arranged opposite to each other. The second upper surface 42a is used to receive the echo signal. The second upper surface 42a is provided with a third optical film, and the second lower surface is provided with a fourth optical film. The reflectivity of the third optical film is greater than the third preset threshold but less than the fourth preset threshold. The reflectivity of the fourth optical film is less than the fifth preset threshold, and the fifth preset threshold is less than the third preset threshold.

[0089] The third optical film adopts a film material with medium to low reflectivity, and the fourth optical film adopts a film material with even lower reflectivity. The materials of the third optical film and the fourth optical film are customized by the designer based on engineering experience.

[0090] The third optical film includes magnesium fluoride film, a multilayer film composed of silicon dioxide and tantalum pentoxide, a multilayer film composed of titanium dioxide and silicon dioxide, a composite film composed of silver and silicon dioxide, a composite film composed of aluminum and magnesium fluoride, and the like.

[0091] The fourth optical film includes a magnesium fluoride single-layer antireflection film, a multilayer antireflection film composed of titanium dioxide and silicon dioxide, a multilayer antireflection film composed of tantalum pentoxide and silicon dioxide, a gradient refractive index nanostructure antireflection film, a porous silicon antireflection film, and the like.

[0092] The third, fourth, and fifth preset thresholds are customized by the designer based on engineering experience. For example, the third preset threshold is any value between 5% and 20%, and the fourth preset threshold is, for example, any value between 10% and 30%. The fifth preset threshold is any value between 1% and 10%, and for example, the fifth preset threshold is 2%.

[0093] In the embodiment of the present application, a film layer having a reflectivity greater than the third preset threshold but less than the fourth preset threshold is selected as the third optical film, and a film layer having a reflectivity less than the fifth preset threshold is selected as the fourth optical film. The third optical film can reduce the incidence rate of the echo signal from the second position range, thereby reducing the energy of the echo signal from the second position range. The fourth optical film can increase the transmittance of the echo signal from the second position range, so that more echo signals can be incident on the laser receiving surface of the laser receiver, thereby avoiding the laser receiver entering a saturation state due to an excessively strong echo signal, which is beneficial to improving the discrimination of the point cloud signal.

[0094] The light adjusting component provided in the embodiments of the present application has various product forms. The following describes the three product forms of the light adjusting component, namely, a curved prism, an arrayed waveguide structure, and a grating waveguide structure. It should be understood that the curved prism, arrayed waveguide structure, and grating waveguide structure mentioned below are not intended to unduly limit the scope of protection of the embodiments of the present application. The details are as follows:

[0095] ① When the light adjustment element is a curved prism:

[0096] The curved prism can not only be used to perform total internal reflection processing on the echo signal from the first position range and then transmit the echo signal processed by total internal reflection to the laser receiving surface of the laser receiver, but also can be used to perform intensity attenuation processing on the echo signal from the second position range and then transmit the echo signal processed by intensity attenuation to the laser receiving surface of the laser receiver.

[0097] Please combine Figure 5 The curved prism includes an optical transmission portion 41 and an optical attenuation portion 42, which are integrally formed. The optical transmission portion 41 is disposed around the laser receiver 300. For example, the optical transmission portion 41 is located on the side of the curved prism away from the laser emitter. The optical attenuation portion 42 is disposed on the laser receiving surface of the laser receiver 300.

[0098] like Figure 5 As shown, the first echo signal 21 is incident on the optical transmission unit 41. The optical transmission unit 41 performs total internal reflection processing on the first echo signal 21 and then transmits the echo signal after the total internal reflection processing to the laser receiving surface of the laser receiver 300. The second echo signal 22 is incident on the optical attenuation unit 42. The optical attenuation unit 42 performs intensity attenuation processing on the second echo signal 22 and then transmits the echo signal after the intensity attenuation processing to the laser receiving surface of the laser receiver 300.

[0099] The incident angle of the echo signal from any incident position of the optical transmission portion in the optical transmission portion is greater than the critical angle. For example, the critical angle is 41.8°.

[0100] According to the law of refraction, when light travels from a denser medium to a less dense medium, there exists a critical angle C that satisfies the following conditions: , n1 is the refractive index of the denser medium, n2 is the refractive index of the less dense medium. If the refractive index of the curved prism is n1=1.5, and the refractive index of air is n2=1, when the echo signal is projected into the air, the critical angle Therefore, when the incident angle of the echo signal from any incident position of the optical transmission part in the optical transmission part is greater than 41.8°, the optical transmission part can perform total internal reflection processing on the echo signal and then transmit the echo signal after the total internal reflection processing to the laser receiving surface of the laser receiver.

[0101] It is understood that the embodiments of this application utilize a laser optical path simulation tool to simulate a curved prism, thereby enabling the curved prism to exhibit the following functionality: the incident angle of the echo signal from any incident position within the optical transmission portion is greater than the critical angle within the optical transmission portion. It is also understood that this simulation method is well known to those skilled in the art and will not be further elaborated upon here. However, the content disclosed in the embodiments of this application is original to the applicant.

[0102] ② When the light adjustment component is an array waveguide structure:

[0103] The arrayed waveguide structure can not only be used to perform total internal reflection processing on the echo signal from the first position range and then transmit the echo signal processed by total internal reflection to the laser receiving surface of the laser receiver, but also can be used to perform intensity attenuation processing on the echo signal from the second position range and then transmit the echo signal processed by intensity attenuation to the laser receiving surface of the laser receiver.

[0104] See also Figure 6 The array waveguide structure includes an optical transmission part 41 and an optical attenuation part 42, and the optical transmission part 41 and the optical attenuation part 42 are integrally formed. The optical transmission part 41 is arranged around the laser receiver 300. For example, the optical transmission part 41 is located on the side of the array waveguide structure away from the laser transmitter. The optical attenuation part 42 is arranged on the laser receiving surface of the laser receiver 300. It can be understood that the orthographic projection of the optical attenuation part 42 on the laser receiving surface at least partially overlaps with the area where the laser receiver is located. Or, as Figure 11 As shown, the orthographic projection of the optical attenuation portion 42 on the laser receiving surface covers the area where the laser receiver is located.

[0105] The optical transmission unit 41 is provided with at least one first reflective surface 43. These surfaces are arranged in a sequence and angled along the direction of light propagation of the echo signal within the optical transmission unit 41. The reflectivity of each first reflective surface 43 is greater than a sixth preset threshold. The first reflective surface 43 is configured to deflect the echo signal from the first position range back to the optical transmission unit 41 for total internal reflection, allowing the echo signal to enter the laser receiving surface of the laser receiver. The sixth preset threshold is customizable by the designer based on engineering experience; for example, the sixth preset threshold is 60%.

[0106] The optical attenuation section 42 is provided with a plurality of second reflective surfaces 44. These second reflective surfaces 44 are sequentially arranged obliquely behind the first reflective surface 43, along the light propagation direction of the echo signal within the optical attenuation section 42. In some embodiments, the mirror distance between any two adjacent second reflective surfaces within the optical attenuation section 42 is equal. The reflectivity of the second reflective surfaces 44 is less than or equal to the reflectivity of the first reflective surface 43. Exemplarily, the reflectivity of the second reflective surfaces 44 is 30%.

[0107] When the echo signal from the first position range enters the optical transmission unit 41, it propagates laterally within the optical transmission unit 41, passing through the first reflection surface 43. The echo signal is then reflected by the first reflection surface 43 toward the second reflection surface 44a. A small portion of the echo signal is able to pass through the second reflection surface 44a, while the majority of the echo signal is reflected by the second reflection surface 44a back to the laser receiving surface of the laser receiver.

[0108] A small portion of the echo signal passes through second reflective surface 44a and continues to propagate forward. When the echo signal that has passed through second reflective surface 44a encounters second reflective surface 44b, a small portion of the echo signal is able to pass through second reflective surface 44b, while the majority of the echo signal is reflected by second reflective surface 44b back to the laser receiving surface of the laser receiver. And so on.

[0109] The embodiment of the present application can reliably deflect the echo signal to the laser receiving surface of the laser receiver by providing a multi-stage second reflection surface 44 .

[0110] When the echo signal from the second position range is incident on the optical attenuation part 42, when the echo signal encounters the second reflection surface 44, most of the echo signal is transmitted through the second reflection surface 44 and enters the laser receiving surface of the laser receiver, and a small part of the echo signal will be reflected by the second reflection surface 44 and cannot enter the laser receiving surface of the laser receiver. In this way, the embodiment of the present application can also attenuate the echo signal to a certain extent through the second reflection surface 44, slightly reduce the intensity of the echo signal from medium and short distances, thereby avoiding excessive attenuation of the echo signal from medium and short distances.

[0111] like Figure 6As shown, the array waveguide structure includes a waveguide upper surface 6a and a waveguide lower surface 6b arranged opposite to each other. The waveguide upper surface 6a is used to receive the echo signal. Along the propagation direction of the light, the first reflection surface and the waveguide upper surface 6a are arranged at an acute angle. The acute angle is [ , ], for example, the acute angle is 45°. Along the light propagation direction, the second reflecting surface 44 is set at an acute angle with the upper surface 6a of the waveguide. The acute angle is [ , ] any value between, for example, the acute angle is 45°.

[0112] It is understandable that the included angle between the second reflecting surface 44 and the waveguide upper surface 6 a may be the same as or different from the included angle between the second reflecting surface 44 and the waveguide upper surface 6 a.

[0113] In some embodiments, along the direction of light propagation, the reflectivity of the last second reflective surface among the multiple second reflective surfaces is greater than a seventh preset threshold, and the seventh preset threshold is greater than the sixth preset threshold. For example, the seventh preset threshold is 100% or 98%, etc.

[0114] See also Figure 7 In this embodiment of the present application, the reflectivity of the last second reflective surface 44c is set to a seventh preset threshold value along the direction of light propagation of the echo signal within the optical transmission unit 41. After the echo signal is reflected by the first reflective surface 43 within the optical transmission unit 41 and then processed by multiple second reflective surfaces 44, a residual echo signal continues to propagate. When the remaining echo signal encounters the last second reflective surface 44c with high reflectivity, the remaining echo signal can be fully or nearly fully deflected to the laser receiving surface of the laser receiver, thereby ensuring that the echo signal is fully or maximally deflected to the laser receiving surface of the laser receiver, which helps improve the signal reception rate of the laser receiver.

[0115] In some embodiments, see Figure 8 In the arrayed waveguide structure, the distances between two adjacent second reflection surfaces 44 are equal, and the projection length of the second reflection surface on the upper surface of the waveguide is equal to the distance between the two adjacent second reflection surfaces 44 .

[0116] The projected length of the second reflection surface 44 on the upper surface of the waveguide is k=h / tanα, where k is the projected length of the second reflection surface on the upper surface of the waveguide, h is the thickness of the arrayed waveguide structure, and α is the angle of the second reflection surface.

[0117] When the distance d between two adjacent second reflective surfaces 44 is equal to the projected length k of the second reflective surfaces 44 on the waveguide surface, the second reflective surfaces are densely arranged within the optical attenuation section 42. When an echo signal is incident on any position of the optical attenuation section 42, the echo signal at any incident position will encounter the second reflective surface, and the transmittance of the echo signal is affected by the second reflective surface. Echo signals from the second position range are likely to encounter the second reflective surface, which attenuates the intensity of the echo signal. The attenuated echo signal then enters the laser receiving surface of the laser receiver.

[0118] In other embodiments, see Figure 9 In the array waveguide structure, the distances between two adjacent second reflection surfaces 44 are equal, and the projection length of the second reflection surface 44 on the upper surface of the waveguide is equal to the target distance, which is the sum of the mirror distance and the preset margin length.

[0119] When k=d+e, e is the preset margin length, k is the projected length of the second reflective surface on the upper surface of the waveguide, and d is the distance between two adjacent second reflective surfaces 44. Compared to the approach in the above embodiment, the second reflective surfaces are sparsely arranged within the optical transmission portion 41 or the optical attenuation portion 42, so that echo signals with an angle less than a preset range with respect to the optical axis of the laser receiver can be incident on the laser receiving surface of the laser receiver from the area corresponding to the preset margin length. In other words, echo signals with a small angle with respect to the optical axis of the laser receiver can directly pass through the arrayed waveguide structure and be received by the laser receiver.

[0120] When the echo signal from a long distance (i.e., the echo signal whose incident angle with the optical axis of the laser receiver is at a small angle) is incident on the laser receiving surface of the laser receiver from the area corresponding to the preset margin length e, the echo signal can directly transmit through the optical attenuation portion 42 and maintain a high energy to be incident on the laser receiving surface of the laser receiver. Therefore, the embodiment of the present application does not attenuate the echo signal with a small angle with the optical axis of the laser receiver to a large extent, ensuring that the echo signal from a long distance maintains a high energy to be incident on the laser receiving surface of the laser receiver, which is beneficial to improving the laser radar's ability to reliably and accurately detect obstacles at a longer distance.

[0121] When the echo signal from medium and short distances (i.e., the echo signal whose incident angle is at a large angle to the optical axis of the laser receiver) is incident on the array waveguide structure, the echo signal is affected by the second reflection surface in the array waveguide, and the echo signal will be reflected multiple times between the second reflection surfaces and then incident on the laser receiving surface of the laser receiver. Therefore, the embodiment of the present application can attenuate the echo signal that is at a large angle to the optical axis of the laser receiver to a certain extent, thereby ensuring that the high-energy echo signal from medium and short distances will not be incident on the laser receiving surface of the laser receiver with higher energy, thereby avoiding saturation of the laser receiver, which is beneficial for the laser radar to reliably and accurately detect obstacles at medium and short distances.

[0122] When the echo signal from a closer distance (due to the light spot offset at a close distance of the off-axis system) will first be incident on at least one first reflection surface in the optical transmission part 41, the echo signal at a closer distance can be incident on the laser receiving surface of the laser receiver after being deflected by the first reflection surface, thereby ensuring that the laser receiver receives the echo signal from a closer distance, so that the laser radar can reliably and accurately detect obstacles at a closer distance.

[0123] In the embodiment of the present application, a first reflecting surface and a second reflecting surface are configured in the light adjusting component according to the following expression k=d+e, so that the light adjusting component can be compatible with reliably and accurately detecting objects at any distance, thereby improving the detection capability of the laser receiving unit in different scenarios.

[0124] ③ When the light adjustment component is a grating waveguide structure:

[0125] The grating waveguide structure can not only be used to perform total internal reflection processing on the echo signal from the first position range and then transmit the echo signal processed by total internal reflection to the laser receiving surface of the laser receiver, but also can be used to perform intensity attenuation processing on the echo signal from the second position range and then transmit the echo signal processed by intensity attenuation to the laser receiving surface of the laser receiver.

[0126] Grating waveguide structure includes surface relief grating structure. For details, please refer to Figures 10a to 10d , the surface relief grating structure is a rectangular grating, or, the surface relief grating structure is a tilted grating, or, the surface relief grating structure is a blazed grating, or, the surface relief grating structure is an analog grating. Figure 10e , the grating waveguide structure is a volume holographic grating structure.

[0127] The grating waveguide structure includes an optical transmission portion 41 and an optical attenuation portion 42. The optical transmission portion 41 is disposed around the laser receiver 300, for example, on the side of the curved prism away from the laser emitter. The optical attenuation portion 42 is disposed on the laser receiving surface of the laser receiver 300.

[0128] See also Figure 11 The optical transmission portion 41 includes a grating portion 111 and a waveguide portion 112. The grating portion 111 is disposed around the laser receiver and above the waveguide portion 112. The grating portion 111 is configured to change the direction of the echo signal from within the first position range incident on the waveguide portion 112, causing the echo signal to undergo total internal reflection in the waveguide portion 112. The diffraction angle of the grating portion is greater than the critical angle of the waveguide portion.

[0129] When the echo signal from the first position range is incident on the grating portion 111, the grating portion 111 diffracts the echo signal into the waveguide portion 112, changing the original propagation direction of the echo signal so that the echo signal undergoes total internal reflection in the waveguide portion 112 and is finally incident on the laser receiving surface of the laser receiver.

[0130] When the echo signal from the second position range is incident on the optical attenuation part 42, the optical attenuation part 42 has no grating structure. Therefore, the propagation direction of the echo signal does not change. The echo signal is incident on the laser receiving surface of the laser receiver after passing through the optical attenuation part 42.

[0131] The embodiment of the present application adopts a grating waveguide structure, which can effectively change the propagation direction of the echo signal from the first position range, so that the echo signal from the first position range can reliably undergo total internal reflection in the waveguide portion 112, and can then reliably enter the laser receiving surface of the laser receiver.

[0132] In order to verify the benefits of the laser receiving unit provided in the embodiment of the present application, the embodiment of the present application combines Figure 12 To explain this:

[0133] like Figure 12 As shown, the closer distance is the distance from r1 to r2.

[0134] The laser radar detects the first object. The energy change of the echo signal reflected by the first object is as follows: Figure 12 As shown in curve 121, in the related art, the energy of the echo signal is relatively weak within the distance between r1 and r2, and the energy of the echo signal detected by the laser receiver does not exceed the detection threshold, resulting in the laser receiver being unable to identify the valid point cloud points detected at a closer distance. As shown in curve 122, in the embodiment of the present application, the energy of the echo signal shows a significant increase within the distance between r1 and r2, and exceeds the detection threshold, and the laser receiver is able to identify the valid point cloud points detected at a closer distance. This shows that the embodiment of the present application deflects the echo signal reflected at a closer distance back to the laser receiving surface, thereby more reliably and accurately detecting objects at a closer distance.

[0135] The medium and short distances are from r2 to r3. Within the range from r2 to r3, the energy of the echo signal shown by curve 121 is higher than the energy of the echo signal shown by curve 122. This shows that the embodiment of the present application attenuates the echo energy at medium and short distances, which can avoid oversaturation of the laser receiver and improve the differentiation of the point cloud.

[0136] The laser radar detects the second object. The energy change of the echo signal reflected by the second object is as follows: Figure 12 As shown. Curve 123 is the energy change curve of the echo signal generated based on the related art, and curve 124 is the energy change curve of the echo signal generated based on the embodiment of the present application. It is understood that the analysis of curves 123 and 124 is as described above and will not be repeated here.

[0137] As another aspect of the present invention, the present invention provides a laser receiving module. Figure 13 The laser receiving module 130 includes at least one laser receiving array, wherein the receiving array can be a receiving linear array or a receiving area array. The laser receiving array includes multiple laser receiving units 200 and a laser receiving board 131 described in the above embodiments. The multiple laser receiving units 200 are arranged on the laser receiving board 131 in a matrix arrangement.

[0138] like Figure 13 As shown, the laser receiving plate 131 is provided with a near-field receiving area 132 and a far-field receiving area 133, and a plurality of laser receiving units 200 are arranged in a matrix arrangement in the near-field receiving area 132 and the far-field receiving area 133 of the laser receiving plate 131, wherein the near-field receiving area 132 is used for arranging the receiving units 200 provided with light adjustment parts, and the far-field receiving area 133 is used for arranging the laser receivers without light adjustment parts.

[0139] As an example, multiple adjacent laser receivers may share the same light adjustment member, wherein the multiple laser receivers may be arranged in a row (e.g., 1xn, n≥1), a column (e.g., nx1, n≥1), or a block (e.g., 3x3, 4x3, 4x4), etc. Figure 14When the laser radar's transmission and reception are arranged in a left-right layout, taking the example of each row of laser receivers sharing the same light adjustment component in the near-field receiving area 132, the row of laser receivers is used to receive the echo signal 141 transmitted by the same light adjustment component and process the echo signal according to the method of the above embodiment. It can be understood that since different rows of laser receiving units 200 correspond to different light adjustment components, this can avoid optical crosstalk between different rows and improve detection reliability. It can be understood that when the laser radar's transmission and reception are arranged in a top-down layout, each column of laser receivers can also share the same light adjustment component in the near-field receiving area 132. The column of laser receivers is used to receive the echo signal 141 transmitted by the same light adjustment component and process the echo signal according to the method of the above embodiment.

[0140] As another example, at least two adjacent rows of receivers may share the same light adjusting member, or at least two columns of receivers may share the same light adjusting member, or at least two adjacent blocks of receivers may share the same light adjusting member. Figure 15 At least two rows of laser receivers are spatially arranged to form a laser receiving array, which is used to receive echo signal 151 transmitted by the same optical adjustment component. Specifically, after entering the optical adjustment component, echo signal 151 is transmitted to at least two rows of laser receivers to form sub-echo signals. Through this structural design, receivers in adjacent rows, columns, or blocks of the array can share an independent channel (i.e., share the same optical adjustment component), and laser receiving units at different positions in the laser receiving array respectively receive sub-echo signals from the corresponding channel. Using this structure, embodiments of the present application can further achieve multiplexing of optical adjustment components of laser receivers in adjacent rows, columns, or blocks, using fewer optical adjustment components to meet the spot offset detection requirements of near-field receivers at different positions.

[0141] As yet another aspect of the embodiments of the present application, the embodiments of the present application provide a laser radar that can be applied to any type of smart device, including vehicles, drones, robots, etc.

[0142] The laser radar includes a laser receiving module and a laser transmitting module. The laser transmitting module includes at least one laser transmitting array, which includes multiple laser emitters and a laser transmitting board. The multiple laser emitters are arranged on the laser transmitting board in an array arrangement. The array arrangement can be, for example, a matrix arrangement. The optical axis of the laser emitter is separated from the optical axis of the laser receiver by a preset distance. The correspondence between laser emitters and receivers can be one laser emitter corresponding to one laser receiver, one emitter corresponding to multiple laser receivers, multiple laser emitters corresponding to one laser receiver (for example, one laser transmitting block corresponding to one laser receiver), or multiple laser emitters corresponding to multiple laser receivers (for example, one laser transmitting block corresponding to one laser receiving block). The correspondence between laser emitters and laser receivers is not limited in this application.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A laser receiving unit, characterized in that: The optical attenuator comprises a laser receiver and a light adjusting member, wherein the light adjusting member comprises an optical transmission portion and an optical attenuation portion. The optical attenuator is an arrayed waveguide structure, wherein the arrayed waveguide structure comprises the optical transmission portion and the optical attenuation portion, and the optical transmission portion and the optical attenuation portion are integrally formed. The optical transmission portion is disposed around the laser receiver, and the optical attenuation portion is disposed on the laser receiving surface of the laser receiver. The optical transmission portion is configured to perform total internal reflection processing on an echo signal from a first position range, and then transmit the echo signal after the total internal reflection processing to a laser receiving surface of the laser receiver. The optical transmission portion is provided with at least one first reflection surface, and the at least one first reflection surface is sequentially and obliquely arranged in the optical transmission portion along a light propagation direction of the echo signal in the optical transmission portion. The reflectivity of the first reflection surface is greater than a sixth preset threshold value. The optical attenuation unit is arranged on the laser receiving surface of the laser receiver, and is configured to perform intensity attenuation processing on the echo signal from the second position range, and then transmit the echo signal after the intensity attenuation processing to the laser receiving surface of the laser receiver. A plurality of second reflection surfaces are provided in the optical attenuation unit. Along the light propagation direction of the echo signal in the optical attenuation unit, the plurality of second reflection surfaces are arranged in sequence and tilted behind the first reflection surface. The reflectivity of the second reflection surface is less than or equal to the reflectivity of the first reflection surface. When the echo signal from the first position range is incident on the optical transmission unit, the echo signal propagates laterally in the optical transmission unit. During the propagation process, the echo signal passes through the first reflection surface, and the echo signal is reflected by the first reflection surface to the second reflection surface. The echo signal can be reflected back to the laser receiving surface by the second reflection surface.

2. The laser receiving unit according to claim 1, characterized in that The orthographic projection of the optical transmission portion on the laser receiving surface is located on a side of the light adjusting component away from the laser emitter.

3. The laser receiving unit according to claim 1, wherein: The optical transmission part includes a first upper surface and a first lower surface arranged opposite to each other, and the first upper surface is configured to receive an echo signal, wherein the first upper surface is provided with a first optical film, and the first lower surface is provided with a second optical film, the reflectivity of the first optical film is less than a first preset threshold, the reflectivity of the second optical film is greater than a second preset threshold, and the second preset threshold is greater than the first preset threshold.

4. The laser receiving unit according to claim 1, wherein: The orthographic projection of the optical attenuation portion on the laser receiving surface at least partially overlaps with the area where the laser receiver is located; or, The orthographic projection of the optical attenuation portion on the laser receiving surface covers the area where the laser receiver is located.

5. The laser receiving unit according to claim 4, characterized in that: The optical attenuation portion includes a second upper surface and a second lower surface arranged opposite to each other, the second upper surface being configured to receive an echo signal, wherein a third optical film is provided on the second upper surface, and a fourth optical film is provided on the second lower surface, the reflectivity of the third optical film is greater than a third preset threshold but less than a fourth preset threshold, the reflectivity of the fourth optical film is less than a fifth preset threshold, and the fifth preset threshold is less than the third preset threshold.

6. The laser receiving unit according to claim 1, characterized in that: The arrayed waveguide structure comprises an upper waveguide surface and a lower waveguide surface arranged opposite to each other, wherein the upper waveguide surface is configured to receive an echo signal, and along the propagation direction of the light, the first reflection surface is arranged at an acute angle to the upper waveguide surface, and / or the second reflection surface is arranged at an acute angle to the upper waveguide surface, wherein the acute angle is [ , ] any value between ].

7. A laser receiving module, characterized in that: It comprises at least one laser receiving array, which comprises a plurality of laser receiving units and a laser receiving board according to any one of claims 1 to 6, and the plurality of laser receiving units are arranged on the laser receiving board in an array arrangement.

8. A laser radar, characterized in that: include: The laser receiving module according to claim 7; The laser emission module includes at least one laser emission array, which includes multiple laser emitters and a laser emission board. The multiple laser emitters are arranged on the laser emission board in an array arrangement, wherein the optical axis of the laser emitter is separated from the optical axis of the laser receiver by a preset distance.

9. A smart device, characterized in that: Including the laser radar as described in claim 8.

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