Lidar system, three-dimensional imaging control method and device

Abstract

The application provides a laser radar system, a three-dimensional imaging control method and device, and relates to the technical field of radar detection. The application performs beam collimation processing on laser beams emitted by multiple emission channels of a semiconductor laser array in a semiconductor fast-axis direction through a fast-axis collimation lens, and performs beam expansion and superposition on the processed laser beams in a semiconductor slow-axis direction through an expansion lens to form a same laser beam, and then performs beam collimation processing on the laser beam in a semiconductor slow-axis direction through a slow-axis collimation lens. The processed laser beam is uniformly lightened by a microlens array and is projected onto a target object surface by a laser scanning component for laser scanning, so that the laser receiving component receives the laser beam reflected by the target object surface through the laser scanning component to obtain a corresponding three-dimensional scanning image, thereby effectively improving the radar resolution while maintaining the size of the whole machine.

Description

Technical Field

[0001] This application relates to the field of radar detection technology, and more specifically, to a lidar system, a three-dimensional imaging control method, and an apparatus. Background Technology

[0002] With the continuous development of science and technology, radar detection technology has gradually matured, and its application in various industries has become increasingly widespread. Among these applications, autonomous driving is a crucial area for radar detection technology. As autonomous driving technology becomes more prevalent, the demands on lidar are also increasing. Current lidar systems can no longer meet the ever-growing radar resolution requirements within the same overall size. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a lidar system, a three-dimensional imaging control method and device, which can effectively reduce the instantaneous field of view of the lidar system in the semiconductor slow axis direction and the semiconductor fast axis direction during the laser scanning process, so as to effectively improve the radar resolution while maintaining the overall size of the machine.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0005] In a first aspect, this application provides a lidar system, the system comprising a semiconductor laser array, a fast-axis collimating lens, a beam expander lens, a slow-axis collimating lens, a microlens array, a laser scanning component, and a laser receiving component;

[0006] The fast-axis collimating lens is disposed in the laser emission path of the semiconductor laser array and is used to collimate the laser beams emitted by the multiple emission channels of the semiconductor laser array in the semiconductor fast-axis direction, wherein the stacking direction of the multiple emission channels is parallel to the semiconductor slow-axis direction.

[0007] The beam expanding lens is disposed on the collimating optical path of the fast-axis collimating lens and is used to expand and overlap the various laser beams processed by the fast-axis collimating lens into a single large laser beam in the semiconductor slow-axis direction.

[0008] The slow-axis collimating lens is disposed in the light transmission path of the beam expander lens and is used to perform beam collimation processing in the semiconductor slow-axis direction on the large laser beam obtained by the beam expander lens.

[0009] The microlens array is disposed in the collimating optical path of the slow-axis collimating lens and is used to homogenize the large laser beam processed by the slow-axis collimating lens.

[0010] The laser scanning component is disposed in the light output path of the microlens array and is used to project the large laser beam processed by the microlens array onto the surface of the target object for laser scanning.

[0011] The laser receiving component is used to receive and image the large laser beam reflected from the surface of the target object by the laser scanning component, thereby obtaining a three-dimensional scan image of the surface of the target object.

[0012] In an optional embodiment, the laser scanning assembly includes a horizontal scanning control device and a vertical scanning control device;

[0013] The vertical scanning control device is disposed in the beam reflection path of the horizontal scanning control device, and is used to project the large laser beam reflected by the horizontal scanning control device from the microlens array onto the surface of the target object for laser scanning, or to reflect the large laser beam from the surface of the target object to the laser receiving component via the horizontal scanning control device; wherein, the horizontal scanning control device is used to control the large laser beam projected onto the surface of the target object to perform laser scanning in the horizontal direction, and the vertical scanning control device is used to control the large laser beam projected onto the surface of the target object to perform laser scanning in the vertical direction.

[0014] In an optional embodiment, the horizontal scanning control device includes a prism, which adjusts the horizontal beam projection position of the large laser beam to be projected through the prism.

[0015] The vertical scanning control device includes a galvanometer, which adjusts the vertical beam projection position of the large laser beam to be projected via the galvanometer.

[0016] In an optional embodiment, the laser receiving component includes a receiving lens group and a receiving chip;

[0017] The receiving lens group is disposed in the beam reflection path of the laser scanning component and is used to converge the large laser beam reflected by the laser scanning component.

[0018] The receiving chip is disposed in the light output path of the receiving lens group and is used to receive and image the large laser beam converged by the receiving lens group.

[0019] In an optional embodiment, the receiving lens group includes a fast-axis receiving cylindrical lens and a slow-axis receiving cylindrical lens.

[0020] The cylindrical extension direction of the fast-axis receiving cylindrical lens is parallel to the direction of the semiconductor fast axis, and is used to adjust the imaging width of the receiving chip;

[0021] The cylindrical extension direction of the slow-axis receiving cylindrical lens is parallel to the slow-axis direction of the semiconductor, and is used to adjust the imaging height of the receiving chip.

[0022] In an optional embodiment, the effective aperture width of the fast-axis collimating lens is greater than or equal to the chip width of the receiving chip, and the effective aperture height of the slow-axis collimating lens is greater than or equal to the chip height of the receiving chip.

[0023] In an optional embodiment, both the fast-axis collimating lens and the slow-axis collimating lens are made of cylindrical lenses;

[0024] The cylindrical extension direction of the fast-axis collimating lens is parallel to the fast-axis direction of the semiconductor, and the cylindrical extension direction of the slow-axis collimating lens is parallel to the slow-axis direction of the semiconductor.

[0025] In an optional embodiment, the lens surface of the beam expander near the fast-axis collimating lens is convex.

[0026] The lens surface of the beam expander lens near the slow-axis collimating lens is either convex or concave.

[0027] Secondly, this application provides a three-dimensional imaging control method, applied to a radar control device communicatively connected to the lidar system described in any of the foregoing embodiments, the method comprising:

[0028] Control each emission channel of the semiconductor laser array to emit a laser beam;

[0029] The laser scanning component controls the laser scanning position of the large laser beam, which has been processed by a fast-axis collimating lens, a beam expander, a slow-axis collimating lens, and a microlens array, and projects it onto the surface of the target object.

[0030] The laser receiving component is controlled to receive and image the large laser beam reflected from the surface of the target object via the laser scanning component, thereby obtaining a three-dimensional scan image of the surface of the target object.

[0031] Thirdly, this application provides a three-dimensional imaging control device, applied to a radar control device communicatively connected to the lidar system described in any of the foregoing embodiments, the device comprising:

[0032] The laser emission control module is used to control each emission channel of the semiconductor laser array to emit a laser beam.

[0033] The laser scanning control module is used to control the laser scanning component to adjust the laser scanning position of the large laser beam obtained by processing through the fast-axis collimating lens, the beam expander, the slow-axis collimating lens and the microlens array on the surface of the target object.

[0034] The laser imaging control module is used to control the laser receiving component to receive and image the large laser beam reflected from the surface of the target object through the laser scanning component, thereby obtaining a three-dimensional scan image of the surface of the target object.

[0035] In this case, the beneficial effects of the embodiments of this application may include the following:

[0036] This application uses a fast-axis collimating lens to collimate the laser beams emitted by multiple emission channels stacked along the semiconductor slow axis of a semiconductor laser array. Then, a beam expander lens expands and merges these individual laser beams along the semiconductor slow axis into a single large laser beam. A slow-axis collimating lens then collimates this large laser beam along the semiconductor slow axis. A microlens array homogenizes this large laser beam, and a laser scanning component projects it onto the surface of a target object for laser scanning. The laser receiving component then receives and images the large laser beam reflected from the target object's surface, obtaining a three-dimensional scanned image of the target object's surface. By utilizing the combined light processing of the fast-axis collimating lens, beam expander lens, and slow-axis collimating lens, the instantaneous field of view along both the semiconductor slow and fast axes of the laser radar system during laser scanning is effectively reduced, thereby improving radar resolution while maintaining the overall system size.

[0037] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the deployment of a lidar system provided in an embodiment of this application;

[0040] Figure 2 A schematic diagram illustrating the composition of the laser receiving component provided in an embodiment of this application;

[0041] Figure 3 This is a schematic diagram illustrating the communication between the lidar system and the radar control device provided in an embodiment of this application.

[0042] Figure 4 A schematic flowchart of the three-dimensional imaging control method provided in the embodiments of this application;

[0043] Figure 5 This is a schematic diagram of the composition of the three-dimensional imaging control device provided in the embodiments of this application.

[0044] Icons: 10-LiDAR system; 11-Semiconductor laser array; 12-Fast axis collimating lens; 13-Beam expander lens; 14-Slow axis collimating lens; 15-Microlens array; 16-Laser scanning assembly; 17-Laser receiving assembly; 171-Receiving lens group; 172-Receiving chip; 20-Radar control equipment; 200-3D imaging control device; 210-Laser emission control module; 220-Laser scanning control module; 230-Laser imaging control module. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0047] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0048] In the description of this application, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0049] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0050] In the description of this application, it should also be understood that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0052] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the deployment of a lidar system 10 provided in an embodiment of this application. In this embodiment, the lidar system 10 may include a semiconductor laser array 11, a fast-axis collimating lens 12, a beam expander lens 13, a slow-axis collimating lens 14, a microlens array 15, a laser scanning component 16, and a laser receiving component 17. Through the coordinated optical processing between the semiconductor laser array 11, the fast-axis collimating lens 12, the beam expander lens 13, and the slow-axis collimating lens 14, the instantaneous field of view angles in the semiconductor slow-axis and semiconductor fast-axis directions during laser scanning of the lidar system 10 are effectively reduced, thereby effectively improving radar resolution while maintaining the overall system size. The semiconductor slow-axis direction is a specific direction parallel to the semiconductor junction plane of the corresponding semiconductor laser array 11, and the semiconductor fast-axis direction is a specific direction perpendicular to the semiconductor junction plane of the corresponding semiconductor laser array 11.

[0053] In this embodiment, the semiconductor laser array 11 has a non-rotationally symmetric waveguide structure. The original laser beam emitted directly from the semiconductor laser array 11 has a large divergence angle in both the semiconductor fast axis and semiconductor slow axis directions, which generally cannot meet the increasingly demanding radar resolution requirements. The semiconductor laser array 11 may include multiple semiconductor chips, each corresponding to one emission channel of the semiconductor laser array 11. The laser beams emitted by the semiconductor laser array 11 through each emission channel are asymmetrical in the semiconductor slow axis and semiconductor fast axis directions. The stacking direction of the multiple emission channels of the semiconductor laser array 11 is parallel to the semiconductor slow axis direction. Furthermore, compared to semiconductor laser arrays where the channel stacking direction is parallel to the semiconductor fast axis direction, the original laser beam emitted by the semiconductor laser array 11 with the channel stacking direction parallel to the semiconductor slow axis direction used in this application has a smaller initial emission angle.

[0054] In this embodiment, since the laser beam emitted by the semiconductor laser array 11 through a single emission channel has different divergence angles in the semiconductor slow axis direction and the semiconductor fast axis direction, the fast axis collimating lens 12 can be disposed in the laser emission optical path of the semiconductor laser array 11 to perform beam collimation processing on the laser beams emitted by the multiple emission channels of the semiconductor laser array 11 in the semiconductor fast axis direction, so as to converge the laser beams emitted by the multiple emission channels in the semiconductor fast axis direction, thereby reducing the divergence angle of the laser beams emitted by the multiple emission channels in the semiconductor fast axis direction, and achieving the collimation effect on the original laser beam emitted by the semiconductor laser array 11 in the semiconductor fast axis direction.

[0055] In this embodiment, the beam expander 13 is disposed on the collimating optical path of the fast-axis collimating lens 12, and is used to expand and merge the various laser beams processed by the fast-axis collimating lens 12 into a single large laser beam in the semiconductor slow-axis direction. This allows the multiple laser beams processed by the fast-axis collimating lens 12 to be converged into a larger emission spot, so that the converged emission spot can be divided into more linear small collimated spots. This ensures that more linear small collimated spots can effectively improve the radar resolution of the lidar system 10 when applied to laser scanning.

[0056] In this embodiment, the slow-axis collimating lens 14 is disposed on the light transmission path of the beam expander lens 13, and is used to perform beam collimation processing on the large laser beam obtained by the beam expander lens 13 in the semiconductor slow-axis direction, so as to converge the large laser beam obtained by the beam expander lens 13 in the semiconductor slow-axis direction, thereby reducing the divergence angle of the large laser beam obtained by the beam expander lens 13 in the semiconductor slow-axis direction, and achieving the collimation effect on the original laser beam emitted by the semiconductor laser array 11 in the semiconductor slow-axis direction.

[0057] In this case, the lidar system 10 provided in this application can effectively reduce the instantaneous field of view angles of the semiconductor slow axis direction and the semiconductor fast axis direction when the lidar system 10 emits laser during laser scanning by means of the light processing cooperation between the fast axis collimating lens 12, the beam expanding lens 13 and the slow axis collimating lens 14.

[0058] In this embodiment, the microlens array 15 is disposed on the collimating optical path of the slow-axis collimating lens 14, and is used to homogenize the large laser beam processed by the slow-axis collimating lens 14. Specifically, by expanding the total size and beam spacing of the laser beam emitted by the semiconductor laser array 11 through the beam expander lens 13, the spacing between the multiple microlens units included in the microlens array 15 can be effectively increased, reducing the fabrication difficulty of the microlens array 15. Simultaneously, the homogenizing effect of the microlens array 15 is effectively improved, avoiding diffraction interference in the homogenized large laser beam and enhancing the beam collimation effect.

[0059] In this embodiment, the laser scanning component 16 is disposed in the light output path of the microlens array 15, and is used to project the large laser beam processed by the microlens array 15 onto the surface of the target object for laser scanning. The laser scanning component 16 can adjust the scanning position of the large laser beam processed by the microlens array 15 in the horizontal and / or vertical directions to achieve the desired scanning field of view in both directions, thereby effectively ensuring that the lidar system 10 can maintain the desired scanning field of view.

[0060] In this embodiment, the laser receiving component 17 is disposed on the beam reflection path of the laser scanning component 16. The laser scanning component 16 can receive a large laser beam reflected from the surface of the target object and reflect the received large laser beam back to the laser receiving component 17 for imaging, thereby obtaining a three-dimensional scanned image of the target object's surface. The laser receiving component 17 can calculate the flight time of the same large laser beam by statistically analyzing the start time and beam scanning direction angle of the large laser beam emitted by the laser scanning component 16, and the end time of the received and reflected large laser beam. Then, it calculates the scanning distance of the large laser beam at the corresponding beam scanning direction angle (i.e., the distance between the laser scanning component 16 and the target object's surface in the scanning direction corresponding to the beam scanning direction angle) according to the standard speed of light and the calculated flight time. At this point, the laser receiving component 17 can perform three-dimensional imaging based on the scanning distance corresponding to different beam scanning direction angles to obtain a three-dimensional scanned image of the target object's surface.

[0061] In this process, it is worth noting that the laser receiving component 17 may include multiple receiving channels, and beams are received through each receiving channel. Specifically, when the beam expanding lens 13 expands and overlaps the laser beams corresponding to the multiple emitting channels in the semiconductor slow axis direction into a single large laser beam, it effectively avoids misalignment and overlap of the laser beams corresponding to different emitting channels when received by the laser receiving component 17, thereby effectively improving laser crosstalk between a single receiving channel of the laser receiving component 17 and other receiving channels.

[0062] Therefore, based on the characteristic that radar resolution is inversely correlated with the emission field of view during radar laser scanning, this application utilizes the optical processing coordination between the fast-axis collimating lens 12, the beam expanding lens 13, and the slow-axis collimating lens 14 to effectively reduce the instantaneous field of view of the laser radar system 10 in the semiconductor slow-axis direction and the semiconductor fast-axis direction during laser scanning, so as to effectively improve radar resolution while maintaining the overall size of the device.

[0063] Optionally, in this embodiment, the laser scanning component 16 may include a horizontal scanning control device and a vertical scanning control device. The horizontal scanning control device controls the large laser beam projected onto the surface of the target object to perform laser scanning in the horizontal direction, and the vertical scanning control device controls the large laser beam projected onto the surface of the target object to perform laser scanning in the vertical direction. The vertical scanning control device is disposed in the beam reflection path of the horizontal scanning control device, so that when the horizontal scanning control device receives the large laser beam from the microlens array 15, the horizontal scanning control device reflects the received large laser beam to the vertical scanning control device, and the vertical scanning control device projects the large laser beam reflected by the horizontal scanning control device onto the surface of the target object for laser scanning. Furthermore, when the vertical scanning control device receives the large laser beam reflected from the surface of the target object, the vertical scanning control device reflects the received large laser beam back to the horizontal scanning control device, and the horizontal scanning control device reflects the received large laser beam to the laser receiving component 17.

[0064] In this embodiment, the horizontal scanning control device includes a prism, and adjusts the beam projection position of the large laser beam to be projected in the horizontal direction using the prism; the vertical scanning control device includes a galvanometer, and adjusts the beam projection position of the large laser beam to be projected in the vertical direction using the galvanometer.

[0065] Alternatively, please refer to Figure 2 , Figure 2 This is a schematic diagram of the composition of the laser receiving component 17 provided in this application embodiment. In this application embodiment, the laser receiving component 17 may include a receiving lens group 171 and a receiving chip 172. The receiving lens group 171 is disposed in the beam reflection path of the laser scanning component 16, and is used to converge the large laser beam reflected by the laser scanning component 16; the receiving chip 172 is disposed in the light output path of the receiving lens group 171, and is used to receive and image the large laser beam converged by the receiving lens group 171. The aforementioned multiple receiving channels are disposed at the receiving chip 172, which may include any one or more photodiodes selected from avalanche photodiodes (APDs), silicon photomultiplier tubes (SiPMs), and single-photon avalanche diodes (Spads), and realizes the light receiving function through the included photodiodes.

[0066] In this process, the receiving lens group 171 can be directly implemented using a standard receiving lens. The overall receiving end field of view (FOV) of the laser receiving component 17 is consistent with the overall emitting end field of view of the laser beam emitted by the laser scanning component 16. At this time, the imaging height (b) of the receiving chip 172, the focal length (f) of the standard receiving lens, and the overall receiving end field of view (FOV) are related by the relationship "b / 2=f*tan(FOV / 2)". Therefore, based on the laser radar system 10, the radar resolution of the focal length laser radar system 10 can be further improved by increasing the focal length of the standard receiving lens.

[0067] The receiving lens group 171 can also be obtained by combining a fast-axis receiving cylindrical lens and a slow-axis receiving cylindrical lens. The cylindrical extension direction of the fast-axis receiving cylindrical lens is parallel to the semiconductor fast-axis direction, used to adjust the imaging width of the receiving chip 172; the cylindrical extension direction of the slow-axis receiving cylindrical lens is parallel to the semiconductor slow-axis direction, used to adjust the imaging height of the receiving chip 172. The field of view (FOV) of the laser receiving assembly 17 at the receiving end in the semiconductor slow-axis direction is the same as the field of view (FOV) of the laser scanning assembly 16 at the emitting end in the semiconductor slow-axis direction when emitting the laser beam. 慢轴 The field of view (FOV) of the laser receiving component 17 in the semiconductor fast axis direction is consistent with that of the laser scanning component 16 when emitting the laser beam in the semiconductor fast axis direction. 快轴 To maintain consistency, the multiple receiving channels of the receiving chip 172 may include at least one receiving channel for the semiconductor fast axis direction (hereinafter referred to as "fast axis receiving channel") and at least one receiving channel for the semiconductor slow axis direction (hereinafter referred to as "slow axis receiving channel").

[0068] In this case, the imaging width (b) of the receiving chip 172 in the semiconductor fast axis direction 快轴 ), fast-axis receiving cylindrical lens focal length (f 快轴 and the field of view (FOV) of the emitter along the fast axis of the semiconductor. 快轴 There is a correlation between "b" and "b". 快轴 / 2=f 快轴 *tan(FOV 快轴 / 2”, the resolution angle (θ) of the lidar system 10 in the semiconductor fast axis direction, and the focal length (f) of the fast axis receiving cylindrical lens. 快轴 There is a correlation between θ and the fast axis receiving channel. 快轴 / Total number of fast axis receiving channels" or "tan(θ) = Size of a single fast axis receiving channel / f 快轴The radar resolution of the receiving chip 172 in the semiconductor fast axis direction is inversely correlated with the angle between the receiving chip 172 and the resolution in the semiconductor fast axis direction.

[0069] The imaging height (b) of the receiving chip 172 in the semiconductor slow axis direction 慢轴 ), slow-axis receiving cylindrical lens focal length (f 慢轴 and the field of view (FOV) of the emitter in the slow axis direction of the semiconductor. 慢轴 There is a correlation between "b" and "b". 慢轴 / 2=f 慢轴 *tan(FOV 慢轴 / 2”, the resolution angle (δ) of the lidar system 10 in the semiconductor slow axis direction, and the focal length (f) of the slow axis receiving cylindrical lens. 慢轴 There is a correlation between the slow axis receiving channel and the slow axis receiving channel: "δ=f" 慢轴 / Total number of slow axis receiving channels" or "tan(δ) = Size of a single slow axis receiving channel / f 慢轴 The radar resolution of the receiving chip 172 in the semiconductor slow axis direction is inversely correlated with the angle between the receiving chip 172 and the resolution in the semiconductor slow axis direction.

[0070] Therefore, when the total number of slow-axis receiving channels and the total number of fast-axis receiving channels are fixed, by reducing the instantaneous field of view corresponding to the semiconductor fast-axis direction and the semiconductor slow-axis direction, the receiving end field of view of the laser receiving component 17 in the semiconductor fast-axis direction and the semiconductor slow-axis direction can be reduced, thereby effectively reducing the resolution angle of the laser receiving component 17 in the semiconductor fast-axis direction and the semiconductor slow-axis direction, and thus effectively improving the radar resolution of the laser receiving component 17 in the semiconductor fast-axis direction and the semiconductor slow-axis direction. At the same time, when the size of a single slow-axis receiving channel and the size of a single fast-axis receiving channel are fixed, by increasing the focal length of the slow-axis receiving cylindrical lens and the fast-axis receiving cylindrical lens, the resolution angle of the laser receiving component 17 in the semiconductor fast-axis direction and the semiconductor slow-axis direction can be effectively reduced, thereby effectively improving the radar resolution of the laser receiving component 17 in the semiconductor fast-axis direction and the semiconductor slow-axis direction.

[0071] In this embodiment, to ensure that the large laser beam projected after being processed by the fast-axis collimating lens 12 and the slow-axis collimating lens 14 can completely cover the receiving chip 172 when it is received by the laser receiving component 17, the effective aperture width of the fast-axis collimating lens 12 must be greater than or equal to the chip width of the receiving chip 172, and the effective aperture height of the slow-axis collimating lens 14 must be greater than or equal to the chip height of the receiving chip 172, so as to ensure that the receiving chip 172 can achieve a complete optical information reception effect.

[0072] In this embodiment, both the fast-axis collimating lens 12 and the slow-axis collimating lens 14 are made of cylindrical lenses. The cylindrical extension direction of the fast-axis collimating lens 12 is parallel to the semiconductor fast-axis direction, so as to effectively achieve beam collimation of the laser beam in the semiconductor fast-axis direction through the cylindrical curvature of the fast-axis collimating lens 12; the cylindrical extension direction of the slow-axis collimating lens 14 is parallel to the semiconductor slow-axis direction, so as to effectively achieve beam collimation of the laser beam in the semiconductor slow-axis direction through the cylindrical curvature of the slow-axis collimating lens 14.

[0073] In this embodiment, the lens surface of the beam expander 13 near the fast-axis collimating lens 12 is convex to focus the received laser beam in the semiconductor slow-axis direction. The lens surface of the beam expander 13 near the slow-axis collimating lens 14 can be either convex or concave to expand the focused laser beam. If a beam expander 13 with a concave lens surface near the slow-axis collimating lens 14 and a beam expander 13 with a convex lens surface near the slow-axis collimating lens 14 have the same laser beam expanding effect, the overall height of the former beam expander 13 is often greater than that of the latter. Therefore, to effectively reduce the overall height of the beam expander 13 in the lidar system 10, the lens surface of the beam expander 13 near the slow-axis collimating lens 14 can be directly set to a convex shape.

[0074] In one embodiment of this invention, the beam expander 13 can be implemented using a thick biconvex lens. This utilizes the negative lens characteristics exhibited by the thick biconvex lens in the aforementioned lidar system 10 to ensure that the beam expander 13 achieves the aforementioned beam expansion function. Simultaneously, it can effectively reduce the overall height of the laser emitting components of the lidar system 10 (including the semiconductor laser array 11, the fast-axis collimating lens 12, the beam expander 13, the slow-axis collimating lens 14, and the microlens array 15), further reducing the overall height of the lidar system 10. Specifically, the lens thickness of the beam expander 13 can be 7.922 cm, the radius of curvature of the lens surface near the fast-axis collimating lens 12 is 1.104 cm, and the radius of curvature of the lens surface near the slow-axis collimating lens 14 is -4.366 cm. In this case, the focal length of the beam expander 13 is negative.

[0075] Alternatively, please refer to Figure 3 , Figure 3This is a schematic diagram illustrating the communication between the lidar system 10 and the radar control device 20 provided in this embodiment. In this embodiment, the lidar system 10 and the radar control device 20 are communicatively connected. The radar control device 20 controls the lidar system 10 to perform radar detection scanning on the surface of a target object, obtaining a three-dimensional scan image of the target object's surface. The radar control device 20 can be, but is not limited to, a smartphone, tablet computer, or in-vehicle computer.

[0076] In this application, to ensure that the radar control device 20 can control the lidar system 10 to achieve high-resolution three-dimensional scanning imaging of the target object surface, this application embodiment provides a three-dimensional imaging control method applied to the radar control device 20 to achieve the aforementioned objective. The three-dimensional imaging control method provided in this application will be described in detail below.

[0077] Please refer to Figure 4 , Figure 4 This is a schematic flowchart of a three-dimensional imaging control method provided in an embodiment of this application. In this embodiment, the three-dimensional imaging control method may include steps S310 to S330.

[0078] Step S310: Control each emission channel of the semiconductor laser array to emit laser beams respectively.

[0079] Step S320: Control the laser scanning component to adjust the laser scanning position of the large laser beam obtained by processing the fast-axis collimating lens, the beam expander, the slow-axis collimating lens and the microlens array on the surface of the target object.

[0080] In this embodiment, the radar control device 20 can continuously adjust the laser scanning position of the large laser beam emitted by the laser scanning component 16 on the surface of the target object by controlling the horizontal scanning control device and the vertical scanning control device included in the laser scanning component 16, so that the laser scanning component 16 can perform a full scan of the surface of the target object.

[0081] Step S330: Control the laser receiving component to receive and image the large laser beam reflected from the surface of the target object through the laser scanning component, and obtain a three-dimensional scan image of the surface of the target object.

[0082] Therefore, by performing the above steps S310 to S330, this application can effectively utilize the high-resolution lidar system 10 to achieve high-resolution three-dimensional scanning imaging of the target object surface.

[0083] In this application, to ensure that the radar control device 20 can execute the aforementioned three-dimensional imaging control method by controlling the three-dimensional imaging control device, this application implements the aforementioned function by dividing the three-dimensional imaging control device into functional modules. The specific composition of the three-dimensional imaging control device provided in this application is described below.

[0084] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the composition of the three-dimensional imaging control device 200 provided in an embodiment of this application. In this embodiment, the three-dimensional imaging control device 200 may include a laser emission control module 210, a laser scanning control module 220, and a laser imaging control module 230.

[0085] The laser emission control module 210 is used to control each emission channel of the semiconductor laser array to emit laser beams.

[0086] The laser scanning control module 220 is used to control the laser scanning component to adjust the laser scanning position of the large laser beam obtained by processing through the fast-axis collimating lens, the beam expander, the slow-axis collimating lens and the microlens array on the surface of the target object.

[0087] The laser imaging control module 230 is used to control the laser receiving component to receive and image the large laser beam reflected from the surface of the target object through the laser scanning component, so as to obtain a three-dimensional scan image of the surface of the target object.

[0088] It should be noted that the basic principle and technical effects of the three-dimensional imaging control device 200 provided in this embodiment are the same as those of the aforementioned three-dimensional imaging control method. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the above description of the three-dimensional imaging control method.

[0089] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of the apparatus, methods, and computer program products according to embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0090] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part. If the function is implemented as a software functional module and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned readable storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0091] In summary, in the lidar system, three-dimensional imaging control method, and apparatus provided in this application, the laser beams emitted by multiple emission channels of a semiconductor laser array stacked along the semiconductor slow axis are collimated in the semiconductor fast axis direction using a fast-axis collimating lens. Then, a beam expander is used to expand and merge the individual laser beams processed by the fast-axis collimating lens into a single large laser beam in the semiconductor slow axis direction. Finally, a slow-axis collimating lens is used to collimate the large laser beam obtained from the beam expander in the semiconductor slow axis direction. Finally, a microlens array is used to collimate the slow-axis collimating lens. The large laser beam is then homogenized and then projected onto the surface of the target object by the laser scanning component, which uses a microlens array to perform laser scanning. This allows the laser receiving component to receive and image the large laser beam reflected from the target object's surface, obtaining a three-dimensional scanned image of the target object's surface. By utilizing the light processing coordination between the fast-axis collimating lens, the beam expanding lens, and the slow-axis collimating lens, the instantaneous field of view in the semiconductor slow-axis and semiconductor fast-axis directions of the lidar system during laser scanning is effectively reduced, thereby effectively improving the radar resolution while maintaining the overall size of the system.

[0092] The above descriptions are merely various embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A lidar system, characterized in that, The system includes a semiconductor laser array, a fast-axis collimating lens, a beam expander lens, a slow-axis collimating lens, a microlens array, a laser scanning component, and a laser receiving component; The fast-axis collimating lens is disposed in the laser emission path of the semiconductor laser array and is used to collimate the laser beams emitted by the multiple emission channels of the semiconductor laser array in the semiconductor fast-axis direction, wherein the stacking direction of the multiple emission channels is parallel to the semiconductor slow-axis direction. The beam expanding lens is disposed on the collimating optical path of the fast-axis collimating lens and is used to expand and overlap the various laser beams processed by the fast-axis collimating lens into a single large laser beam in the semiconductor slow-axis direction. The slow-axis collimating lens is disposed in the light transmission path of the beam expander lens and is used to perform beam collimation processing in the semiconductor slow-axis direction on the large laser beam obtained by the beam expander lens. The microlens array is disposed in the collimating optical path of the slow-axis collimating lens and is used to homogenize the large laser beam processed by the slow-axis collimating lens. The laser scanning component is disposed in the light output path of the microlens array and is used to project the large laser beam processed by the microlens array onto the surface of the target object for laser scanning. The laser receiving component is used to receive and image the large laser beam reflected from the surface of the target object by the laser scanning component, thereby obtaining a three-dimensional scan image of the surface of the target object.

2. The system according to claim 1, characterized in that, The laser scanning assembly includes a horizontal scanning control device and a vertical scanning control device; The vertical scanning control device is disposed in the beam reflection path of the horizontal scanning control device, and is used to project the large laser beam reflected by the horizontal scanning control device from the microlens array onto the surface of the target object for laser scanning, or to reflect the large laser beam from the surface of the target object to the laser receiving component via the horizontal scanning control device; wherein, the horizontal scanning control device is used to control the large laser beam projected onto the surface of the target object to perform laser scanning in the horizontal direction, and the vertical scanning control device is used to control the large laser beam projected onto the surface of the target object to perform laser scanning in the vertical direction.

3. The system according to claim 2, characterized in that, The horizontal scanning control device includes a prism, which adjusts the horizontal beam projection position of the large laser beam to be projected through the prism. The vertical scanning control device includes a galvanometer, which adjusts the vertical beam projection position of the large laser beam to be projected via the galvanometer.

4. The system according to any one of claims 1-3, characterized in that, The laser receiving component includes a receiving lens group and a receiving chip; The receiving lens group is disposed in the beam reflection path of the laser scanning component and is used to converge the large laser beam reflected by the laser scanning component. The receiving chip is disposed in the light output path of the receiving lens group and is used to receive and image the large laser beam converged by the receiving lens group.

5. The system according to claim 4, characterized in that, The receiving lens group includes a fast-axis receiving cylindrical lens and a slow-axis receiving cylindrical lens; The cylindrical extension direction of the fast-axis receiving cylindrical lens is parallel to the direction of the semiconductor fast axis, and is used to adjust the imaging width of the receiving chip; The cylindrical extension direction of the slow-axis receiving cylindrical lens is parallel to the slow-axis direction of the semiconductor, and is used to adjust the imaging height of the receiving chip.

6. The system according to claim 4, characterized in that, The effective aperture width of the fast-axis collimating lens is greater than or equal to the chip width of the receiving chip, and the effective aperture height of the slow-axis collimating lens is greater than or equal to the chip height of the receiving chip.

7. The system according to claim 1, characterized in that, Both the fast-axis collimating lens and the slow-axis collimating lens are made of cylindrical lenses; The cylindrical extension direction of the fast-axis collimating lens is parallel to the fast-axis direction of the semiconductor, and the cylindrical extension direction of the slow-axis collimating lens is parallel to the slow-axis direction of the semiconductor.

8. The system according to claim 1, characterized in that, The lens surface of the beam expander lens near the fast-axis collimating lens is convex. The lens surface of the beam expander lens near the slow-axis collimating lens is either convex or concave.

9. A three-dimensional imaging control method, characterized in that, A radar control device communicatively connected to a lidar system according to any one of claims 1-8, the method comprising: Control each emission channel of the semiconductor laser array to emit a laser beam; The laser scanning component controls the laser scanning position of the large laser beam, which has been processed by a fast-axis collimating lens, a beam expander, a slow-axis collimating lens, and a microlens array, and projects it onto the surface of the target object. The laser receiving component is controlled to receive and image the large laser beam reflected from the surface of the target object via the laser scanning component, thereby obtaining a three-dimensional scan image of the surface of the target object.

10. A three-dimensional imaging control device, characterized in that, A radar control device communicatively connected to a lidar system according to any one of claims 1-8, the device comprising: The laser emission control module is used to control each emission channel of the semiconductor laser array to emit a laser beam. The laser scanning control module is used to control the laser scanning component to adjust the laser scanning position of the large laser beam obtained by processing through the fast-axis collimating lens, the beam expander, the slow-axis collimating lens and the microlens array on the surface of the target object. The laser imaging control module is used to control the laser receiving component to receive and image the large laser beam reflected from the surface of the target object through the laser scanning component, thereby obtaining a three-dimensional scan image of the surface of the target object.

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