Laser radar detection method

Abstract

This invention relates to the field of distance detection technology and provides a lidar and lidar detection method. The lidar includes a receiving module and multiple transmitting modules, the combined emission field of view of the multiple transmitting modules matching the receiving field of view of the receiving module; each transmitting module includes a laser and an emission optical component located on the laser's emission side; the area of ​​the projection region of the laser's emission region onto the light-incident surface of the emission optical component is smaller than the area of ​​the light-incident surface; the emission optical component guides the laser beam emitted by the laser, so that the emission field of view angles of the multiple transmitting modules overlap; the lidar and lidar detection method provided by this invention, while ensuring a small size for each individual optical component, can avoid the occurrence of point cloud defects in the center field of view of the receiving module.

Description

Technical Field

[0001] This invention belongs to the field of distance detection technology, and particularly relates to a lidar detection method. Background Technology

[0002] As an active ranging device, the ranging performance of lidar is affected by various factors (such as power, stray light, and receiver aperture size). Currently, the emission power of lidar is limited by the size of the transmitting chip; the larger the transmitting chip, the greater the emission power. However, a larger transmitting chip also leads to more difficult hardware driving, inconsistent uniformity of the emitted light, and increased manufacturing costs.

[0003] Meanwhile, due to the limitations of the system architecture of the transmitting chip and the receiving detector, LiDAR cannot be designed as a coaxial system. Designing it as a coaxial system would significantly increase the cost and size of the LiDAR. Therefore, LiDAR is generally designed as an off-axis system. However, this type of LiDAR is limited by the aperture of the transmitting and receiving lenses, inevitably resulting in a certain distance between the transmitting lens and the receiving optical components, causing pixel offset. When a LiDAR has one receiving module and multiple transmitting modules, pixel offset often leads to the receiving module lacking a point cloud in the central field of view.

[0004] Therefore, it is essential to provide a lidar detection method that has a small emitter chip size and can avoid missing point clouds in the intermediate field of view. Summary of the Invention

[0005] The purpose of this invention is to provide a lidar detection method that features a small laser size and avoids the loss of point clouds in the intermediate field of view.

[0006] The present invention is implemented as follows: In a first aspect, a lidar is provided, including a receiving module and multiple transmitting modules, wherein the combination of the transmitting fields of view of the multiple transmitting modules is matched with the receiving field of view of the receiving module;

[0007] Each of the emitting modules includes a laser and an emitting optical component located on the light-emitting side of the laser; the area of ​​the projection region of the laser's light-emitting region onto the light-incident surface of the emitting optical component is smaller than the area of ​​the light-incident surface; the emission field of view of multiple emitting modules overlaps.

[0008] In an optional implementation, the receiving module has a first optical axis; the emitting optical component has a second optical axis for guiding at least a portion of the laser beam toward the side where the first optical axis is located.

[0009] Furthermore, the second optical axis of the emitting optical components of the plurality of emitting modules is parallel to the first optical axis of the receiving optical component; the center of the light-emitting region of the laser of the plurality of emitting modules is located on the side of the second optical axis of their respective emitting optical elements away from the first optical axis.

[0010] In an optional embodiment, the emitting optical components are used to perform angle reduction and beam expansion processing on the laser beam emitted by the laser; each of the emitting optical components includes an angle reduction component and a beam expansion component; the angle reduction component includes at least one lens for reducing the divergence angle of the laser beam and guiding at least a portion of the laser beam to be emitted toward the side where the first optical axis is located; the beam expansion component includes at least one lens for expanding the total emission field of view of the laser beam.

[0011] In another optional implementation, the second optical axis of the emitting optical component of the emitting module is set at an acute angle to the first optical axis of the receiving optical component; the emitting optical component is used to perform angle reduction and beam expansion processing on the laser beam emitted by the laser, so that the emission field of view of the multiple emitting modules overlaps.

[0012] In another alternative embodiment, each of the emitting optical components includes an angle reduction component, a beam expander component, and a beam homogenizer disposed along the emission optical path of the laser beam; the angle reduction component includes at least one lens for reducing the divergence angle of the laser beam; the beam expander component includes at least one lens for expanding the total emission field of view of the laser beam; and the beam homogenizer is used to expand the spot of the laser beam so that the emission field of view of the multiple emitting modules overlaps.

[0013] In one specific implementation, the receiving module includes a receiving optical component and a receiving sensor located on the light-emitting side of the receiving optical component; the receiving optical component includes a beam-shrinking component and a converging component arranged along the propagation optical path of the echo signal; the beam-shrinking component includes at least one lens for reducing the total receiving field of view of the echo signal; the converging component includes at least one lens for focusing the echo signal, after the field of view has been reduced by the beam-shrinking component, onto the receiving sensor.

[0014] Furthermore, the transmitting optical components of the multiple transmitting modules are all distortion-matched with the receiving optical components of the receiving module.

[0015] In one alternative embodiment, each of the emitting optical components includes at least one lens and satisfies the following condition: |m1|≤0.25%, where m1 is the f-theta distortion of the emitting optical component and |m1| is the absolute value of the f-theta distortion of the emitting optical component.

[0016] The receiving optical component includes at least one lens and satisfies the following condition: |n1|≤0.25%, where n1 is the f-theta distortion of the receiving optical component and |n1| is the absolute value of the f-theta distortion of the receiving optical component.

[0017] Furthermore, the laser includes a first light-emitting unit and a second light-emitting unit alternately arranged on the emitting plate along a first direction. The first light-emitting unit includes a first light source spaced apart along a second direction, and the second light-emitting unit includes a second light source spaced apart along a second direction. The second light source is located between two adjacent first light sources, and the second direction is perpendicular to the first direction.

[0018] Secondly, a lidar detection method is provided, based on the lidar provided in the above embodiments, including the following steps:

[0019] Obtain the distance to the target object;

[0020] Pixel offset parameters are calculated based on the distance to the target object; the pixel offset parameters include any one of pixel offset angle, offset size, and offset pixel number.

[0021] The correspondence between the laser in the transmitting module and the receiving sensor in the receiving module is determined based on the pixel offset parameters.

[0022] The laser in the control transmitting module emits light sequentially according to a preset timing sequence, while the receiving sensor in the control receiving module receives echo signals in a corresponding time interval according to the correspondence with the laser. The corresponding time interval is the preset time interval after the corresponding laser emits light.

[0023] The technical advantages of this invention compared to the prior art are as follows: The lidar provided in the embodiments of this invention includes a receiving module and multiple transmitting modules, wherein the combination of the transmitting field of view of the multiple transmitting modules is matched with the receiving field of view of the receiving module. This allows the size of the laser used in a single transmitting module to be smaller, thereby effectively reducing the power and cost of a single transmitting module. It also makes the related hardware driver easier to operate, and the position and light emission effect of a single transmitting module are easier to adjust, thus making it easier to ensure that the light emitted by multiple transmitting modules is evenly distributed.

[0024] Meanwhile, the transmitting module includes a transmitting optical component and a laser. The area of ​​the laser's projection onto the light-incident surface of the transmitting optical component is smaller than the area of ​​the light-incident surface. The transmitting optical component guides the laser beam so that the transmitting field of view of multiple transmitting modules overlaps. This overlapping area covers the central field of view, ensuring that even with pixel shifts during close-range detection by the lidar, the central field of view is still illuminated by laser light. This results in a point cloud in the central field of view of the receiving module, effectively preventing the point cloud from being missing in the central field of view of the receiving module. Furthermore, the center of the light-emitting area is located on the side of the second optical axis away from the receiving module. The transmitting optical component has a second optical axis and is used to guide at least a portion of the laser light to be emitted towards the side where the first optical axis is located, so that the transmitting field of view of multiple transmitting modules overlaps. This structure further reduces the size of the laser used in a single transmitting module. It also changes the inherent pattern in conventional lidar where small-volume lasers emit laser light entirely in a direction away from the first optical axis. Instead, it sets the emission direction of at least some lasers to face the side of the first optical axis, resulting in overlapping fields of view for multiple transmitting modules. This overlapping area covers the central field of view, ensuring that even with pixel shifts, the central region of the target object is still illuminated by laser light during close-range measurements. This also ensures that the central field of view of the receiving module contains a point cloud, effectively preventing point cloud loss in the central field of view of the receiving module.

[0025] In summary, the lidar provided in this embodiment of the invention, while ensuring a small size for each laser, can also avoid point cloud gaps in the center field of view of the receiving module. The lidar detection method provided in this embodiment of the invention, based on the lidar provided in this embodiment, can also achieve the above-mentioned effects. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the light emission effect of an existing off-axis optical system;

[0028] Figure 2 This is a schematic diagram of the optical path of a lidar provided in an embodiment of the present invention;

[0029] Figure 3 yes Figure 2A comparison of the optical paths of the receiving module and one of the transmitting modules when detecting targets at different detection distances;

[0030] Figure 4(a) is Figure 3 A schematic diagram of the light spot received by the receiving module when detecting target 1. The solid circle in the figure corresponds to the light spot emitted by one of the transmitting modules, and the dashed circle in the figure corresponds to the light spot emitted by the other transmitting module.

[0031] Figure 4(b) is Figure 3 A schematic diagram of the light spot received by the receiving module when detecting target 2. The solid circle in the figure corresponds to the light spot emitted by one of the transmitting modules, and the dashed circle in the figure corresponds to the light spot emitted by the other transmitting module.

[0032] Figure 5 yes Figure 2 A schematic diagram of the structure of the transmitting module used in the process;

[0033] Figure 6 yes Figure 2 A schematic diagram of the receiving module used in the process;

[0034] Figure 7 This is a schematic diagram of the optical path of a lidar provided in another embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the optical path of a lidar provided in another embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the optical path of a lidar provided in another embodiment of the present invention;

[0037] Figure 10 This is a schematic diagram of the structure of the transmitting module used in another embodiment of the present invention;

[0038] Figure 11 This is a schematic diagram showing the positional relationship between the first light-emitting unit and the second light-emitting unit used in an embodiment of the present invention;

[0039] Figure 12 This is a schematic diagram of the arrangement of light sources in a laser used in another embodiment of the present invention;

[0040] Figure 13 This is a schematic diagram of the arrangement of receiving units in a receiving detector used in an embodiment of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 100. Receiver module; 110. Receiver optical assembly; 111. Fifth lens; 112. Sixth lens; 113. Seventh lens; 114. Eighth lens; 115. Ninth lens; 116. Tenth lens; 120. Receiver detector; 121. Receiver unit; 130. Receiver plate; 140. First optical axis; 200. Transmitter module; 210. Transmitter optical assembly; 211. Second optical axis; 212. First lens; 213. Second lens; 214. Third lens; 215. Fourth lens; 216. Beam leveler; 220. Laser; 222. First light-emitting unit; 2221. First light source; 223. Second light-emitting unit; 2231. Second light source; 230. Transmitter plate; 300. Blind spot light source. Detailed Implementation

[0043] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means a plurality or more, unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of multiple components or the interaction relationship of multiple components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0048] like Figure 1 As shown, in existing off-axis optical systems, the emission field of view of the transmitting module 200 on the right corresponds to the receiving field of view of the receiving module 100 on the left. Furthermore, as the detection distance decreases, the central field of view is not illuminated, resulting in no point cloud in the central field of view of the receiving module 100. In existing off-axis optical systems, at close range, the central field of view of the target is not illuminated, leading to a blank area in the central field of view of the receiving module 100. The closer the detection distance, the larger the area without point cloud in the central field of view of the receiving module 100 becomes. However, lidar focuses on the central field of view; the absence of point cloud in the central field of view at close range is unacceptable. If multiple lidars are stitched together, all will display no point cloud in the center at close range.

[0049] Please refer to Figures 2 to 8 As shown, in one embodiment of the present invention, a lidar is provided. The lidar in this embodiment can be a solid-state lidar, used for navigation and obstacle avoidance, obstacle recognition, ranging, speed measurement, and autonomous driving functions in products such as automobiles, robots, logistics vehicles, and inspection vehicles.

[0050] The lidar includes a receiving module 100 and multiple transmitting modules 200. The receiving module 100 receives echo signals. The transmitting modules 200 emit detection lasers. The combined field of view of the multiple transmitting modules 200 is matched with the receiving field of view of the receiving module 100. This matching means that the combined field of view of the multiple transmitting modules 200 is greater than or equal to the receiving field of view of the receiving module 100.

[0051] It is understandable that "multiple" refers to two or more; when there are two transmitting modules 200, the two transmitting modules 200 are respectively set on both sides of the receiving module 100; when there are three or more transmitting modules 200, the multiple transmitting modules 200 are arranged around the receiving module 100.

[0052] More specifically, the emission field of view of multiple transmitting modules 200 can be equal or unequal. Generally, the sum of the emission field of view of multiple transmitting modules 200 should be equal to the receiving field of view of the receiving module 100. Let's take an example where there are two transmitting modules 200, and both have the same emission field of view. α1 = α2, and α1 + α2 = α3; where α1 is the emission field of view of one transmitting module 200, α2 is the emission field of view of the other transmitting module 200, and α3 is the receiving field of view of the receiving module 100. However, in practice, sometimes the edge field of view may lack point cloud coverage. Therefore, in the design, the sum of the emission field of view of multiple transmitting modules 200 can be set to be greater than the receiving field of view of the receiving module 100, so that the edge field of view of the lidar has point cloud coverage.

[0053] In this embodiment, the structures of the multiple emitting modules 200 can be identical or different. When the multiple emitting modules 200 are identical, assembly and positioning are more convenient compared to multiple different emitting modules 200, since the parameters of the multiple emitting modules 200 are the same. When the structures of the multiple emitting modules 200 are not completely identical, the combination of the multiple emitting modules 200 can be more diversified, which can meet more application scenarios. At the same time, using multiple emitting modules 200 can make the size of the emitting chip used in each emitting module 200 smaller, thereby effectively reducing the power and cost of a single emitting module 200. It can also make the related hardware drivers easier to operate, and the position and light emission effect of a single emitting module 200 are easier to adjust, thus making it easier to ensure that the light emitted by the multiple emitting modules 200 is evenly distributed.

[0054] The receiving module 100 has a first optical axis 140. The transmitting module 200 includes a transmitting optical component 210 and a laser 220. The laser 220 is located on the light-incident side of the transmitting optical component 210 and is used to emit laser light into the transmitting optical component 210. The area of ​​the projection region of the laser 220 onto the light-incident surface of the transmitting optical component 210 is smaller than the area of ​​the light-incident surface, so that the laser light emitted by the laser 220 can be incident on the transmitting optical component 210. Specifically, the laser 220 may include multiple independently arranged light emitters, or include a circuit board and multiple light emitters electrically connected to the circuit board. The light-incident region of the laser 220 is the combined region of the light-incident portions of the aforementioned light emitters. The aforementioned light emitters may be a transmitting chip, or a combination of a transmitting chip and a corresponding driving device.

[0055] In this embodiment, the laser 220 and the emitting optical component 210 can have various positional relationships. For example, the center of the light-emitting area of ​​the laser 220 can be located on the side of the second optical axis 211 away from the receiving module 100, or on the side of the receiving module 100, or on the second optical axis 211. The specific relationship can be determined based on factors such as the specific structure of the emitting optical component 210, the light-emitting effect, and the echo signal reception effect; no single limitation is made here. Specifically, the laser 220 in this embodiment generally includes multiple light emitters arranged in an array or other regular pattern. The center of the light-emitting area refers to the center of the regular shape formed by the multiple light emitters. For example, when the multiple light emitters form a rectangle in a two-dimensional array, the center of the light-emitting area is the intersection of the two diagonals of the rectangle; when the multiple light emitters are distributed in a circular array, the overall shape is circular, and the center of the light-emitting area is the center of the circle. The center of the light-emitting area is located on the side of the second optical axis 211 away from the receiving module 100 or on the side of the receiving module 100. It can be that the entire light-emitting area is located on the side of the second optical axis 211 away from the receiving module 100 or on the side of the receiving module 100, or more than half of the light-emitting area is located on the side of the second optical axis 211 away from the receiving module 100 or on the side of the receiving module 100. The specific choice can be made according to the detection needs, and there is no unique limitation here.

[0056] In one exemplary embodiment, when the number of transmitting modules 200 is two, the transmission field of view θ of the transmitting module 200 is... 发 It can be 0 < θ 发 ≤90 degrees. Specifically, the number of light-emitting units in the laser 220 can be designed according to actual needs, or the degree to which the emitting optical component 210 deflects the light can be designed to obtain the required emission field of view; the receiving field of view θ of the receiving module 100. 收 It can be 0 < θ 发 ≤180 degrees. Specifically, the receiving optical component 110 can be designed according to actual needs.

[0057] When the laser 220 includes an emitting chip, the entire light-emitting area is located on the side of the optical axis of the emitting optical component 210 away from the receiving module 100. Specifically, the emitting chip corresponding to the emitting module 200 on the left is positioned on the left side of the optical axis of the corresponding emitting optical component 210, and the emitting chip corresponding to the emitting module 200 on the right is positioned on the right side of the optical axis of the corresponding emitting optical component 210. Conversely, the entire light-emitting area is located on the side of the optical axis of the emitting optical component 210 closer to the receiving module 100. Specifically, the emitting chip corresponding to the emitting module 200 on the left is positioned on the right side of the optical axis of the corresponding emitting optical component 210, and the emitting chip corresponding to the emitting module 200 on the right is positioned on the left side of the optical axis of the corresponding emitting optical component 210.

[0058] The emitting optical component 210 has a second optical axis 211 and is used to collimate, expand, and guide at least a portion of the laser beam toward the side where the first optical axis 140 is located, so that the emission fields of the multiple emitting modules 200 have overlapping areas. In this embodiment, the emitting optical component 210 may include one or more lenses, and may also include other optical elements besides lenses that can cooperate with lenses to achieve the above-mentioned effects, such as light homogenizers, prisms, etc., as long as they can achieve the above-mentioned effects; no single limitation is made here.

[0059] The detection principle of the lidar provided in this embodiment of the invention is as follows:

[0060] Laser 220 emits a laser beam, which is then collimated, diffused, and has its propagation direction changed by the emitting optical component 210 before being emitted toward the target object. The laser beam is then reflected by the target object to form an echo signal, which is received and processed by the receiving module 100 to obtain information such as the distance and external shape of the target object.

[0061] During the above process, when the laser passes through the emitting optical component 210, at least a portion of the laser can change its original propagation direction through the emitting optical component 210, so that the emission field of view of multiple emitting modules 200 overlaps. This overlapping area covers the central field of view, so that when the lidar performs close-range detection, even if there is pixel shift, the central field of view will still be illuminated by laser, thereby making the central field of view of the receiving module 100 have point cloud, effectively avoiding the occurrence of point cloud missing phenomenon in the central field of view of the receiving module.

[0062] In one alternative implementation, at least a portion of the laser can be redirected by the emitting optical component 210 to propagate toward the side of the first optical axis 140 of the receiving module 100, so that the lasers emitted by the multiple emitting optical components are cross-emitted instead of being emitted outwards as in the prior art. This results in the lasers emitted by the multiple emitting modules 200 having an overlapping area in the central region of the target, i.e., a light spot in the central region of the target, thereby creating a point cloud in the central field of view of the receiving module 100.

[0063] Meanwhile, since the emission angle of each transmitting module 200 remains unchanged, and the target object is relatively close (i.e., the closer the detection distance, the larger the reflection angle of the laser after reflection from the target object), the more the light spot on the receiving image plane of the receiving module 100 shifts towards the center. This solves the problem of no point cloud in the central field of view at close range. It should be noted that the "close range" mentioned here has a certain range; when it is less than the minimum critical distance, the phenomenon of missing point cloud in the central field of view will still occur.

[0064] The lidar provided in this embodiment of the invention includes a receiving module 100 and multiple transmitting modules 200, wherein the multiple transmitting modules 200 are arranged around the receiving module 100, and the combination of the transmitting field of view of the multiple transmitting modules 200 matches the receiving field of view of the receiving module 100. This allows the size of the laser 220 used in a single transmitting module 200 to be smaller, thereby effectively reducing the power and cost of a single transmitting module 200. It also makes the related hardware drivers easier to operate, and the position and light emission effect of a single transmitting module 200 are easier to adjust, thus making it easier to ensure that the light emitted by the multiple transmitting modules 200 is evenly distributed.

[0065] Meanwhile, the emitting module 200 includes an emitting optical component 210 and a laser 220. The area of ​​the projection region of the laser 220 on the light-incident surface of the emitting optical component 210 is smaller than the area of ​​the light-incident surface of the emitting optical component 210. The center of the light-emitting region is located on the side of the second optical axis 211 away from the receiving module 100 or on the side of the receiving module 100. The emitting optical component 210 has a second optical axis 211 and is used to collimate, expand, and guide at least a portion of the laser beam toward the side where the first optical axis 140 is located, so that the emission fields of the multiple emitting modules 200 overlap. This structure further reduces the size of the laser 220 used in a single transmitting module 200. It also changes the inherent pattern in conventional lidar where the small-volume laser 220 emits laser light entirely in a direction away from the first optical axis 140. Instead, it sets the emission direction of at least some of the lasers 220 to face the side of the first optical axis 140. This results in overlapping fields of view for multiple transmitting modules 200, with this overlapping area covering the central field of view. Therefore, even with pixel shifts, the central region of the target will still be illuminated by laser light when the lidar performs close-range measurements. This ensures that the central field of view of the receiving module 100 contains a point cloud, effectively preventing point cloud loss in the central field of view of the receiving module 100.

[0066] In summary, the lidar provided by the embodiments of the present invention can avoid the occurrence of point cloud missing phenomena in the center field of view of the receiving module 100 while ensuring that the size of a single laser 220 is small.

[0067] Please refer to Figures 2 to 9As shown, in one specific embodiment, the lidar includes two transmitting modules 200, which are respectively disposed on opposite sides of the receiving module 100. This allows the emission fields of the two transmitting modules 200 to be roughly distributed on both sides of the receiving module 100, facilitating reception by the receiving module 100. Furthermore, the roughly distributed emission fields of the two transmitting modules 200 also facilitate the adjustment of at least one transmitting module 200 so that the emission fields of the two transmitting modules 200 overlap in the central field of view, ensuring that the emission fields of view fill the entire receiving field of view of the receiving module 100 and avoiding detection blind spots.

[0068] The transmitting module 200 in the above embodiments has multiple implementation methods. For ease of understanding, examples are given below.

[0069] The first implementation method, such as Figure 2 As shown:

[0070] The centers of the light-emitting regions of the lasers 220 of the multiple emitting modules 200 are all located on the side of the second optical axis 211 away from the receiving module 100. This can be either the entire light-emitting region located on the side of the second optical axis 211 away from the receiving module 100, or more than half of the light-emitting region located on the side of the second optical axis 211 away from the receiving module 100.

[0071] The emitting optical assembly 210 includes a reduction angle assembly and a beam expander assembly disposed along the emission optical path of the laser. The reduction angle assembly includes at least one lens and is used to reduce the divergence angle of the laser and guide the laser to be collimated towards the side where the first optical axis 140 is located. The beam expander assembly includes at least one lens and is used to expand the total emission field of view of the laser after it has been collimated by the reduction angle assembly.

[0072] Specifically, in this embodiment, the laser 220 is located at the object-side focal plane of the angle-reduction component, and the angle-reduction component collimates the laser output from the laser 220. The beam expander expands the field of view of the light signal directed towards the detection area by deflecting the light signal after collimation by the angle-reduction component. Both the angle-reduction component and the beam expander in this embodiment may include one or more lenses, and may also include optical elements other than lenses that can achieve corresponding optical effects (such as plane mirrors, prisms, etc.). In some embodiments, the angle-reduction component uses a collimating lens, and the beam expander uses a beam expander.

[0073] In this embodiment, more than half of the light-emitting area is located on the side of the second optical axis 211 away from the receiving module 100. That is, more than half of the light-emitting area of ​​the laser 220 corresponding to the transmitting module 200 on the left is set on the left side of the corresponding second optical axis 211, and more than half of the light-emitting area of ​​the laser 220 corresponding to the transmitting module 200 on the right is set on the right side of the corresponding second optical axis 211. This is so that most of the light emitted by each transmitting module 200 (except for light parallel to the second optical axis 211) can be emitted toward the direction of the first optical axis 140, instead of being emitted toward the direction away from the first optical axis 140 as in the prior art.

[0074] Preferably, the lasers 220 of the multiple transmitting modules 200 are all located on the side of the second optical axis 211 of their respective transmitting optical elements 210 that is away from the first optical axis 140. The transmitting modules 200 adopt this structure, which is simple in structure. In addition to the light rays parallel to the second optical axis 211, the remaining light rays emitted by the transmitting modules 200 can be emitted in the direction of another transmitting module 200. As the detection distance decreases from far to near, the light rays emitted by the multiple transmitting modules 200 will all deflect towards the direction closer to the center field of view, which can effectively avoid the occurrence of point cloud missing phenomenon in the center field of view of the receiving module 100, and the effect is good.

[0075] The second implementation method, taking two transmitting modules 200 as an example, has the center of the light-emitting area of ​​the laser 220 of one transmitting module 200 located on the side of the second optical axis 211 of the corresponding transmitting optical component 210 away from the receiving module 100, and the center of the light-emitting area of ​​the laser of the other transmitting module 200 located on the side of the second optical axis 211 of the corresponding transmitting optical component 210 close to the receiving module 100. The center of the light-emitting area located on the side of the second optical axis 211 away from the receiving module 100 can be either entirely located on the side of the second optical axis 211 away from the receiving module 100, or more than half of the light-emitting area can be located on the side of the second optical axis 211 away from the receiving module 100. Similarly, the center of the light-emitting area located on the side of the second optical axis 211 close to the receiving module 100 can be either entirely located on the side of the second optical axis 211 close to the receiving module 100, or more than half of the light-emitting area can be located on the side of the second optical axis 211 close to the receiving module 100.

[0076] In this embodiment, among the multiple emitting modules 200, at least a portion of the laser beam emitted by the emitting module 200 whose light-emitting area is located on the side of the second optical axis 211 away from the receiving module 100 is emitted towards the side of the first optical axis. As the detection distance increases, the pixels of this portion of the laser beam (denoted as the first laser beam) will shift towards the direction closer to the center of the field of view. At least a portion of the laser beam emitted by the emitting module 200 whose light-emitting area is located on the side of the second optical axis 211 close to the receiving module 100 is emitted away from the first optical axis. As the detection distance increases, the pixels of this portion of the laser beam (denoted as the second laser beam) will shift away from the direction of the center of the field of view. As long as, at the same detection distance, the offset of the pixels of the first laser beam towards the direction closer to the center of the field of view is greater than or equal to the offset of the pixels of the second laser beam towards the direction away from the center of the field of view, the phenomenon of missing point clouds in the center of the field of view of the receiving module 100 can be effectively avoided.

[0077] Specifically, in this embodiment, the laser 220 is located on the object-side focal plane of the angle reduction assembly. The structures of the angle reduction assembly and the beam expander assembly can be the same as or different from the first implementation, as long as the above-mentioned effects can be achieved. In this embodiment, the beam homogenizer 216 can be a diffuser, or other beam homogenizers that can achieve the above-mentioned effects.

[0078] In this embodiment, more than half of the light-emitting area is located on the side of the second optical axis 211 closer to the receiving module 100. That is, more than half of the light-emitting area of ​​the laser 220 corresponding to the transmitting module 200 on the left is set on the left side of the corresponding second optical axis 211, and more than half of the light-emitting area of ​​the laser 220 corresponding to the transmitting module 200 on the right is set on the right side of the corresponding second optical axis 211, so that at least part of the light emitted by each transmitting module 200 (excluding light rays parallel to the second optical axis 211) can be emitted toward the direction of the first optical axis 140, instead of all of them being emitted toward the direction away from the first optical axis 140.

[0079] In this manner, the light emitted by the laser 220 propagates in a direction away from or parallel to the second optical axis 211 after passing through the emitting optical component 210. However, after passing through the light homogenizer 216, some of the light is emitted towards another emitting module 200, which can also prevent the occurrence of point cloud missing phenomena in the center field of view of the receiving module 100.

[0080] The third implementation method, such as Figure 8 As shown:

[0081] The center of the light-emitting region is located on the side of the second optical axis 211 closer to the receiving module 100. The emitting optical assembly 210 includes a reduction angle assembly, a beam expander assembly, and a homogenizer 216 arranged along the emission optical path of the laser. The reduction angle assembly includes at least one lens and is used to reduce the divergence angle of the laser; the beam expander assembly includes at least one lens and is used to expand the total emission field of view of the laser after collimation by the reduction angle assembly. The homogenizer 216 is used to expand the spot of the laser beam after beam expansion by the beam expander assembly, so that the emission field of view of the multiple emitting modules 200 overlap.

[0082] Specifically, in this embodiment, the light source assembly 220 is located on the object-side focal plane of the angle reduction assembly. The structures of the angle reduction assembly and the beam expander assembly can be the same as or different from the first implementation method, as long as the above-mentioned effects can be achieved. In this embodiment, the light homogenizer 216 can be a diffuser, or other light homogenizers that can achieve the above-mentioned effects.

[0083] Of course, the transmitting module 200 is not limited to the two implementation methods mentioned above. Other structures can be used in other embodiments. The specific choice can be made flexibly according to the needs of use. No single limitation is made here.

[0084] While the first implementation method described above compensates for the point cloud in the central field of view, it results in missing point clouds in the edge field of view when measuring certain distances. To further address this issue, such as... Figure 2 , Figures 5 to 10 As shown, in an optional embodiment, the lidar further includes blind spot light sources 300 corresponding one-to-one with the plurality of lasers 220, with the blind spot light sources 300 located on the side of the corresponding laser 220 away from the receiving module 100. At least a portion of the light emitted by the blind spot light source 300 is located outside the light emitted by the corresponding laser 220. Specifically, the blind spot light source 300 in this embodiment can be the same as or different from the laser 220, and is not limited to a single one. The size and model of the emitting area of ​​the blind spot light source 300, the spacing between it and the corresponding laser 220, and other information can be determined according to the missing area of ​​the edge region of the receiving field of view, and is not limited to a single one. In use, the light emitted by the blind spot light source 300 can illuminate the edge region of the target object, thereby causing point clouds to exist in the edge field of view of the receiving module 100.

[0085] Reference Figure 5 As shown, in an optional embodiment, the emitting optical component 210 includes a first lens 212, a second lens 213, a third lens 214, and a fourth lens 215, wherein the angle reduction component includes the first lens 212, the second lens 213, and the third lens 214, and the beam expansion component includes the fourth lens 215.

[0086] This application does not limit the number of lenses included in the angle reduction component, as long as it can reduce the field of view of the laser and collimate the laser; similarly, it does not limit the number of lenses included in the beam expander component, as long as it can expand the emission field of view. The combination of the emission optical components 210 has diverse features and can meet more application needs.

[0087] In the above embodiments, the second optical axis 211 can be parallel to the first optical axis 140 or set at an acute angle. The specific form and angle can be flexibly set according to the light emission requirements. When the second optical axis 211 is parallel to the first optical axis 140, it is convenient to set the optical path. When the second optical axis 211 and the first optical axis 140 are set at an acute angle, compared with the second optical axis 211 being parallel to the first optical axis 140, the overlapping area of ​​the emission field of view of the multiple emission modules 200 can be set to be larger. This allows the central area of ​​the receiving field of view to still have point clouds when the target object is close. At the same time, the structure of the emission optical element does not need to be very complex to achieve the same effect as when the second optical axis 211 is parallel to the first optical axis 140.

[0088] In the above embodiments, as Figure 9 As shown, the receiving module 100 includes a receiving optical component 110, a receiving detector 120 located on the imaging side of the receiving optical component 110, and a receiving plate 130 electrically connected to the receiving detector 120. The receiving optical component 110 is used to perform beam-shrinking and focusing processing on the echo signal.

[0089] The receiving optical component 110 in this embodiment may include one or more lenses, and may also include other optical elements besides lenses that can cooperate with lenses to achieve the above-mentioned effects, such as prisms, as long as they can achieve the above-mentioned effects; no single limitation is made here. The receiving detector 120 may include multiple detectors arranged in an array. The number of detectors may be the same as or different from the number of light emitters. That is, the detectors may be set in a one-to-one correspondence with the light emitters in the transmitting module 200, or one light emitter may correspond to multiple detectors. The specific choice can be flexibly made according to the receiving effect, and no limitation is made here. The receiving board 130 is used to provide power to the detectors in the receiving detector 120, control their opening and closing, and receive data from the receiving detectors. The receiving module 100 adopts the structure of this embodiment, which is simple in structure and easy to assemble.

[0090] In an optional embodiment, the receiving optical component includes a beam-shrinking component and a converging component disposed along the propagation optical path of the echo signal; the beam-shrinking component includes at least one lens for reducing the total receiving field of view of the echo signal; the converging component includes at least one lens for focusing the echo signal, after the field of view has been reduced by the beam-shrinking component, onto the receiving detector.

[0091] More specifically, the beam-shrinking component reduces the total field of view of the echo signal by deflecting the light rays; the receiving detector is located on the image-side focal plane of the converging component and is used to focus the light signal, after the field of view has been reduced by the beam-shrinking component, onto the receiving detector.

[0092] Reference Figure 6 As shown, in an optional embodiment, the receiving optical component 110 includes a fifth lens 111, a sixth lens 112, a seventh lens 113, an eighth lens 114, a ninth lens 115, and a tenth lens 116; wherein the beam-shrinking component includes the fifth lens 111, and the converging component includes the sixth lens 112, the seventh lens 113, the eighth lens 114, the ninth lens 115, and the tenth lens 116.

[0093] This application does not limit the number of lenses included in the angle reduction component, as long as it can reduce the field of view of the echo signal and receive echo signals with a large field of view; similarly, it does not limit the number of lenses included in the converging component, as long as it can focus the echo signal onto the receiving detector 120. The combination of the receiving optical components 110 has diverse characteristics and can meet more usage requirements.

[0094] Furthermore, in order to solve the problem of mismatched lens distortion between the lens in the transmitting optical assembly and the lens in the receiving optical assembly, which leads to a decrease in the ranging performance of the ranging device, the transmitting optical assemblies 220 of the multiple transmitting modules 200 provided in this application embodiment are all mismatched with the receiving optical assemblies 120 of the receiving module 100.

[0095] Specifically, each emitting optical component 220 includes at least one lens and satisfies the following condition: |m1|≤0.25%, where m1 is the f-theta distortion of the emitting optical component 220 and |m1| is the absolute value of the f-theta distortion of the emitting optical component 220; wherein, the emitting lens 112 satisfies the following condition: m1=[( f1*θ1- f1*tanθ1) / f1*θ1] *100%, where: f1 is the effective focal length of the emitting optical component 220 in mm; θ1 is the total emission field of view of the emitting optical component 220, 0<θ1<π. As can be seen from the above conditional equation, the f-theta distortion m1 of the transmitting optical component 220 is related to the effective focal length f1 and the total emission field of view θ1 of the transmitting optical component 220. By reasonably designing the effective focal length f1 and the total emission field of view θ1 of the transmitting optical component 220, the absolute value of the f-theta distortion of the transmitting optical component 220 can be made less than or equal to 0.25%. The principle is simple and easy to design.

[0096] Specifically, the receiving optical component 120 includes at least one lens and satisfies the following condition: |n1|≤0.25%, where n1 is the f-theta distortion of the receiving optical component 120 and |n1| is the absolute value of the f-theta distortion of the receiving optical component 120; wherein, the receiving optical component 120 also satisfies the following condition: n1=[( f2*θ2- f2*tanθ2) / f2*θ2] *100%, where: f2 is the effective focal length of the receiving optical component 120 in mm; θ2 is the total receiving field of view of the receiving optical component 120, 0<θ2<π. As can be seen from the above conditional equation 2, the f-theta distortion of the receiving optical component 120 is related to the effective focal length f2 and the total receiving field of view θ2 of the receiving optical component 120. By reasonably designing the effective focal length f2 and the total receiving field of view θ2 of the receiving optical component 120, the absolute value of the f-theta distortion of the receiving optical component 120 can be made less than or equal to 0.25%. The principle is simple and easy to design.

[0097] The lidar provided in this application controls the absolute values ​​of the f-theta distortion of the transmitting optical component 220 and the receiving optical component 120 to be less than or equal to 0.25%, so that the distortion of the transmitting lens and the receiving lens are matched, thereby solving the problem in related technologies where the ranging performance of the ranging device is reduced due to the mismatch of the distortion of the transmitting lens and the receiving lens.

[0098] In the above embodiments, the transmitting optical component 210 and the receiving optical component 110 may have the same or different structures. When their structures are the same, the assembly direction of the transmitting optical component 210 along the laser optical path is opposite to the assembly direction of the receiving optical component 110 along the echo signal optical path. This not only facilitates design and installation but also facilitates distortion matching between the transmitting and receiving lenses, ensuring that the absolute values ​​of the f-theta distortion of both the transmitting and receiving lenses are controlled to be less than or equal to 0.25%. This solves the problem in related technologies where the ranging performance of the ranging device degrades due to distortion mismatch between the transmitting and receiving lenses.

[0099] In an optional embodiment, such as Figure 11 As shown, the laser 220 includes first light-emitting units 222 and second light-emitting units 223 arranged alternately along a first direction. Each first light-emitting unit includes first light sources 2221 spaced apart along a second direction, and each second light-emitting unit includes second light sources 2231 spaced apart along the second direction. The second light sources 2231 are located between two adjacent first light sources 2221, and the second direction is perpendicular to the first direction. The emission module 200 also includes an emission plate 230 electrically connected to each laser 220 in a one-to-one correspondence. The emission plate 230 is used to drive each light source in the laser 220 to emit light sequentially according to a preset timing sequence.

[0100] like Figure 13 As shown, the receiving detector 120 includes multiple receiving units 121 arranged in a two-dimensional array on the receiving plate 130; the receiving plate 130 is used to drive the receiving units 121 to receive echo signals according to a preset timing sequence.

[0101] Each light source corresponds to multiple receiving units 121 arranged in a two-dimensional array, and all light sources are combined to form a light-emitting area.

[0102] Specifically, the laser 220 in this embodiment can be composed of a single emitting chip or multiple light-emitting chips spliced ​​together. Each light-emitting chip can be provided with a first light-emitting unit and a second light-emitting unit. When the laser 220 is composed of multiple light-emitting chips spliced ​​together, the multiple light-emitting chips can be designed for horizontal field-of-view splicing, vertical field-of-view splicing, or simultaneous splicing of horizontal and vertical field-of-view. Similarly, multiple lidar sensors can also be spliced ​​together, including horizontal field-of-view splicing, vertical field-of-view splicing, or simultaneous splicing of horizontal and vertical field-of-view. When stitching together the fields of view of multiple lidars, it is necessary to consider that at close range, the lidar spot will shift towards the center of the field of view, resulting in areas of the edge field of view without light illumination. In this case, it is necessary to ensure that when stitching together the fields of view of two connected lidars, the edge fields of view at close range must at least meet. That is, the overlapping field of view of connected lidars at far range is at least the edge field of view range without point cloud at close range. Alternatively, the edge fields of view of multiple lidars can be overlapped. The overlapping pixels can be stitched together according to the number of pixel offsets at the closest measurement distance. In this way, there will be no gaps in the stitching of the fields of view of multiple lidars.

[0103] In practical applications, the first light source 2221 and the second light source 2231 can be either continuous emission light sources or pulsed emission light sources. The first light source 2221 and the second light source 2231 can be one or more combinations of light-emitting diodes (LEDs), laser diodes (LDs), and vertical-cavity surface-emitting lasers (VCSELs). This embodiment is not limited to the type of light source. The receiving unit 121 in this embodiment is a laser detector, and each receiving unit 121 can include one or more laser detectors, which can be flexibly selected according to the application requirements. The laser detector can be one or more combinations of avalanche photodiodes (APDs), single-photon avalanche diodes (SPADs), silicon photomultipliers (SiPMs), and multi-pixel photon counters (MPPCs).

[0104] The laser 220 provided in this embodiment allows for the placement of more light sources within a limited space, thereby effectively increasing the light source coverage area on the emitting plate 230 and the number of point clouds received per unit area by the receiving module 100, thus improving the detection accuracy of the lidar. Simultaneously, the correspondence between one light source and multiple receiving units 121 effectively reduces the probability of missing point clouds, further enhancing the detection accuracy of the lidar.

[0105] In an optional embodiment, the emission field of view of each light-emitting unit in the same column is the same and / or the emission field of view of each light-emitting unit in the same row is the same; the receiving field of view of each receiving unit in the same column is the same and / or the receiving field of view of each receiving unit in the same row is the same, so as to facilitate the splicing design of the receiving field of view and the emission field of view.

[0106] Please refer to Figure 12 and Figure 13 As shown, in another embodiment of the present invention, a lidar detection method is provided, based on the lidar provided in the above embodiment, including the following steps:

[0107] S1. Obtain the distance to the target object;

[0108] Specifically, the distance to a target can be detected using lidar.

[0109] S2. Calculate pixel offset parameters based on the target distance; pixel offset parameters include any one of pixel offset angle, offset size, and number of offset pixels.

[0110] Specifically, the degree of pixel offset can be derived from the following formulas: θ =artan(baseline / l H= fθ n = H / s, where θ The value is in radians, and the baseline is the distance between the first optical axis 140 and the second optical axis 211. l To measure distance, f For the focal length of the receiving optical component 110, n is the number of pixels offset, and s is the pixel size of the receiving detector. θ, H, and n can all represent the degree of offset. θ H represents the offset angle, H represents the offset size, and n represents the integer obtained by dividing the offset size by the received pixel size.

[0111] In the above expressions, the baseline is fixed after the LiDAR model is fixed or before measurement, and l is the target distance. During detection, the above formulas, the known distance between the first optical axis 140 and the second optical axis 211, and the detected target distance can be used to easily calculate offset parameters such as pixel offset angle, offset size, and number of offset pixels.

[0112] S3. Determine the correspondence between each light source in the transmitting module and each receiving unit in the receiving module based on the pixel offset parameters;

[0113] Because there is generally a one-to-one correspondence between the light source in the transmitting module and the receiving unit in the receiving module, that is, when a certain light source X emits light, there is a corresponding receiving unit Y in the receiving module to receive it. However, at close range, the position of the laser emitted by light source X on the receiving detector is offset. At this time, in order to detect the laser emitted by light source X, receiving unit Y cannot be used to receive it. In this case, the control system inside the lidar will adaptively adjust the receiving unit. For example, at a distance D1, receiving unit Y1 is used to receive the laser emitted by light source X; at a distance D2, receiving unit Y2 is used to receive the laser emitted by light source X; and at a distance D3, receiving unit Y3 is used to receive the laser emitted by light source X. Since the relationship between offset and distance can be obtained according to the above calculation formula, a lookup table can be stored in the data processing system according to the formula. This lookup table stores the correspondence between distance D and receiving unit. The control system can match different receiving units for receiving according to different distances, so that the echo signal illuminating the area of ​​the receiving unit can be received by the corresponding receiving unit, and irrelevant receiving units can be not activated, thereby avoiding power waste.

[0114] S4. Control each light source in the transmitting module to emit light sequentially according to a preset timing sequence, and simultaneously control each receiving unit in the receiving module to receive echo signals in the corresponding time interval according to the correspondence with each light source. The corresponding time interval is the preset time interval after the corresponding light source emits light.

[0115] Specifically, the sequential emission of light according to a preset timing sequence can mean that the light sources on a preset trajectory emit light sequentially, or that they emit light row by row or column by column, or that the emission order of each light source can be set by the user so that each light source emits light sequentially according to the above emission order. The specific choice can be made flexibly according to actual needs, and there is no single limitation here.

[0116] The aforementioned preset time interval can be within 1 second, 5 seconds, or other time periods after the light source emits light, depending on the reception effect.

[0117] To make it easier to understand, an example is given below.

[0118] The lidar includes two transmitting modules, which are located on opposite sides of the receiving module. Figure 1 This is a schematic diagram of a laser. Figure 2 This is a schematic diagram of a receiving detector; taking a 16*12 column of transmitting chips as an example; the transmission order is to transmit the first column first, then the second column, and so on up to the 12th column (from the diagram, it is from left to right); for each column, the first chip is transmitted first, then the second chip, and so on up to the 16th chip (from the diagram, it is from top to bottom).

[0119] When the distance to the target is D1, it can be set that when the first laser beam in the first column of the right-side transmitting module is emitted, the first 4*8 (rows 1-4 * columns 1-8) receiving unit in the first group of the receiving detector will receive it; when the second laser beam in the first column of the right-side transmitting module is emitted, the second 4*8 (rows 5-8 * columns 1-8) receiving unit in the first group of the receiving detector will receive it; and so on until the 16th laser beam in the right-side transmitting module is emitted, the 16th 4*8 (rows 61-64 * columns 1-8) receiving unit in the first group of the receiving detector will receive it.

[0120] When the first module in the second column of the transmitting module on the right emits a laser, the first 4*8 (rows 1-4 * columns 9-16) receiving unit in the second group of the receiving detector receives it. When the second module in the first column emits a laser, the second 4*8 (rows 5-8 * columns 9-16) receiving unit in the second group of the receiving detector receives it. And so on until the 16th module emits a laser, the 16th 4*8 (rows 61-64 * columns 9-16) receiving unit in the second group of the receiving detector receives it.

[0121] Up to the 12th column, 12 * 8 = 96 columns, so the 96 receiving units located on the left side of the receiving detector can receive the echo signals corresponding to the 12 light sources. Since there are two transmitting modules, there are at least 96 * 2 = 192 receiving units in the receiving detector.

[0122] When the target distance is D2, which is less than D1, the echo signal corresponding to the same laser line shifts position on the receiving module, specifically moving away from the corresponding light source. Therefore, the correspondence between the light source and the receiving unit needs to be adjusted accordingly. For example, when the target distance is D1, the laser emitted by the first light source is received through receiving units in rows 1-4. When the target distance is D2, this needs to be adjusted to be received by receiving units in rows 2-5. When the target distance is D3 (D3 is less than D2), it may be necessary to use receiving units in rows 2-6. This correspondence can be stored in the built-in data processing system of the lidar or in a data processing system connected to the lidar using a lookup table. When in use, after calculating the corresponding pixel offset parameters, the lookup table is consulted to find the corresponding light source and receiving unit relationship. The lidar's operating state is then adaptively adjusted according to this relationship to achieve accurate detection.

[0123] The lidar detection method provided in this invention is based on the lidar provided in the above embodiments. While ensuring that the size of a single laser is small, it can also avoid the occurrence of point cloud defects in the center field of view of the receiving module. At the same time, by using the lidar detection method provided in this invention, the correspondence between the light source and the receiving unit can be adaptively adjusted according to the distance to the target object (i.e., the degree of pixel offset), thereby achieving precise control of the receiving unit and avoiding energy waste.

[0124] The above description is merely a preferred embodiment of the present invention and only specifically describes the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and should not be construed as limiting the scope of protection of the present invention in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention, as well as other specific embodiments of the present invention that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of the present invention.

Claims

1. A lidar detection method, based on lidar, wherein the lidar includes a receiving module and multiple transmitting modules, and the combination of the transmitting fields of view of the multiple transmitting modules is matched with the receiving field of view of the receiving module; Each of the emitting modules includes a laser and an emitting optical component located on the laser's emission side; the area of ​​the projection region of the laser's emission region onto the light-incident surface of the emitting optical component is smaller than the area of ​​the light-incident surface; the emitting optical component is used to guide the laser beam emitted by the laser, so that the emission field of view of the multiple emitting modules overlaps; characterized in that: The lidar detection method includes the following steps: Obtain the distance to the target object; Pixel offset parameters are calculated based on the distance to the target object; the pixel offset parameters include any one of pixel offset angle, offset size, and offset pixel number. The correspondence between the laser in the transmitting module and the receiving sensor in the receiving module is determined based on the pixel offset parameters. The laser in the control transmitting module emits light sequentially according to a preset timing sequence, while the receiving sensor in the control receiving module receives echo signals in a corresponding time interval according to the correspondence with the laser. The corresponding time interval is the preset time interval after the corresponding laser emits light.

2. The lidar detection method as described in claim 1, characterized in that: The receiving module has a first optical axis; the transmitting optical component has a second optical axis for guiding at least a portion of the laser beam toward the side where the first optical axis is located.

3. The lidar detection method according to claim 2, characterized in that: The second optical axes of the transmitting optical components of the plurality of transmitting modules are all parallel to the first optical axis of the receiving module; The center of the light-emitting region of the lasers of the multiple emission modules is located on the side of the second optical axis of their respective emission optical elements that is away from the first optical axis.

4. The lidar detection method according to claim 3, characterized in that: The emitting optical component is used to reduce the angle and expand the beam of the laser emitted by the laser. Each of the emitting optical components includes an angle reduction component and a beam expander component; the angle reduction component includes at least one lens for reducing the divergence angle of the laser beam and guiding at least a portion of the laser beam toward the side where the first optical axis is located; the beam expander component includes at least one lens for expanding the total emission field of view of the laser beam.

5. The lidar detection method according to claim 2, characterized in that: The second optical axis of the transmitting optical component of the transmitting module is set at an acute angle to the first optical axis of the receiving module; the transmitting optical component is used to perform angle reduction and beam expansion processing on the laser beam emitted by the laser, so that the emission field of view of the multiple transmitting modules overlaps.

6. The lidar detection method according to claim 1, characterized in that: Each of the emitting optical components includes an angle reduction component, a beam expander component, and a beam homogenizer disposed along the emission optical path of the laser beam; the angle reduction component includes at least one lens for reducing the divergence angle of the laser beam; the beam expander component includes at least one lens for expanding the total emission field of view of the laser beam; the beam homogenizer is used to expand the spot of the laser beam so that the emission field of view of the multiple emitting modules overlaps.

7. The lidar detection method according to any one of claims 1-6, characterized in that: The receiving module includes a receiving optical component and a receiving sensor located on the light-emitting side of the receiving optical component; the receiving optical component includes a beam-shrinking component and a converging component arranged along the propagation optical path of the echo signal; the beam-shrinking component includes at least one lens for reducing the total receiving field of view of the echo signal; the converging component includes at least one lens for focusing the echo signal, after the field of view has been reduced by the beam-shrinking component, onto the receiving sensor.

8. The lidar detection method according to any one of claims 1-6, characterized in that: The transmitting optical components of the multiple transmitting modules are all distortion-matched with the receiving optical components of the receiving module.

9. The lidar detection method according to any one of claims 1-6, characterized in that: The laser includes a first light-emitting unit and a second light-emitting unit that are staggered on an emitting plate along a first direction. The first light-emitting unit includes a first light source that is spaced apart along a second direction. The second light-emitting unit includes a second light source that is spaced apart along a second direction. The second light source is located between two adjacent first light sources. The second direction is perpendicular to the first direction.

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