Laser radar

Abstract

The present application is applicable to the technical field of laser radars, and provides a laser radar, comprising: a transceiving module (100), a scanning module (200), a conical lens (300), and a conical reflecting mirror (400) which are sequentially arranged in an emitting direction of detection light. The tip of the conical lens (300) and the tip of the conical reflecting mirror (400) are arranged opposite to each other, and the optical axes of the conical lens (300) and the conical reflecting mirror (400) are located on the same straight line. The detection light can sequentially pass through the scanning module (200), the conical lens (300), and the conical reflecting mirror (400) to irradiate a target area, and is reflected by an obstacle in the target area to form echo light; and the echo light can sequentially pass through the conical reflecting mirror (400), the conical lens (300), and the scanning module (200), and is finally received and processed by the transceiving module (100). The laser radar provided by the present application can achieve 360° multi-line scanning, and has a simple architecture, high reliability, and a low price.

Description

LiDAR

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on July 27, 2023, with application number PCT / CN2023 / 109612 and application name “Lidar”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of laser radar technology, and in particular to a laser radar. Background Art

[0003] LiDAR architectures can be categorized by scanning angle into 360-degree surround-view LiDAR and forward-looking LiDAR. Compared to forward-looking LiDAR, 360-degree surround-view LiDAR offers a wider field of view and a more comprehensive understanding of the environment. However, current 360-degree surround-view LiDARs utilize a rotating system to achieve multi-line scanning, resulting in a complex architecture. Technical issues

[0004] The purpose of the embodiments of the present application is to provide a laser radar. Technical Solutions

[0005] The technical solution adopted in the embodiment of this application is:

[0006] A laser radar is provided, comprising a transceiver module, a scanning module, a conical lens, and a conical reflector, which are sequentially arranged along the emission direction of detection light, wherein the tips of the conical lens and the conical reflector are arranged opposite to each other and their optical axes are located on the same straight line;

[0007] The transceiver module is used to provide detection light and also to receive and process echo light;

[0008] The scanning module is used to change the propagation direction of the detection light and the echo light;

[0009] The conical lens is used for allowing the detection light and the echo light to pass through, and is also used for correcting the detection light and the echo light;

[0010] The conical reflector is used to reflect the detection light and the echo light;

[0011] The detection light can pass through the scanning module, the conical lens, and the conical reflector in sequence to irradiate the target area, and be reflected by the obstacles in the target area to form the echo light. The echo light can pass through the conical reflector, the conical lens, and the scanning module in sequence, and finally be received and processed by the transceiver module.

[0012] In some embodiments, the transceiver module includes a light source, a collimating lens, a receiving module and a spectrometer module, the collimating lens is located on the light output side of the light source, the spectrometer module is located on the light output side of the light source, and the receiving module is located on the light output side of the spectrometer module;

[0013] The light source is used to provide the detection light;

[0014] The collimating lens is used to collimate the detection light;

[0015] The receiving module is used to receive and process the echo light;

[0016] The light splitting module is used to allow one of the detection light and the echo light to pass through, and to reflect the other light.

[0017] In some embodiments, the transceiver module further includes a cylindrical mirror located between the light source and the spectrometer module, and the cylindrical mirror is used to allow the detection light to pass through, so as to cooperate with the conical lens to correct the detection light.

[0018] In some embodiments, the equivalent curvature radius of the light incident surface and / or the light exit surface of the cylindrical mirror is adjustable.

[0019] In some embodiments, the equivalent radius of curvature is -200 mm to 200 mm.

[0020] In some embodiments, the cylindrical mirror is a liquid zoom lens, a liquid crystal lens, or an adjustable metasurface lens.

[0021] In some embodiments, the cylindrical mirror can be moved between the light source and the light splitting module.

[0022] In some embodiments, the laser radar also includes an angle expansion lens group, which is arranged between the scanning module and the conical lens. The angle expansion lens group is used to expand the output angle of the detection light and is also used to cooperate with the conical lens to correct the detection light.

[0023] In some embodiments, the angle expansion lens group includes at least two convex lenses arranged in sequence along the emission direction of the detection light;

[0024] Alternatively, the angle expansion lens group includes a convex lens and a concave lens sequentially arranged along the emitting direction of the detection light.

[0025] In some embodiments, the cone angle of the conical lens is 40°~120°, and the cone angle of the conical reflector is 40°~120°.

[0026] In some embodiments, the conical reflector includes a plurality of conical surfaces, and the conical lens also includes a plurality of conical surfaces;

[0027] In the same mirror body, the cone angles of all the conical surfaces decrease successively from the tip to the other end of the mirror body.

[0028] In some embodiments, the conical reflector includes three conical surfaces, and the conical lens also includes three conical surfaces;

[0029] In the same mirror body, the cone angles of the three conical surfaces decrease successively from the tip to the other end of the mirror body, and the cone angle of each conical surface is within a preset range, which is 40°~120°. Beneficial effects

[0030] The beneficial effect of the laser radar provided by the embodiment of the present application is that it includes a transceiver module, a scanning module, a conical lens and a conical reflector arranged in sequence along the emission direction of the detection light, the conical lens and the tip of the conical reflector are arranged relative to each other and the optical axes of the two are located on the same straight line, wherein the setting of the conical reflector can cooperate with the scanning module to achieve 360° multi-line detection, so that the laser radar can use one or several transceiver pairs to achieve multi-line scanning, and there is no linear correlation between the number of lines and the number of transceiver pairs, which can reduce the number of transceiver pairs required in the transceiver module of the laser radar, thereby reducing the production cost of the transceiver module and the laser radar, and can adapt to the cost requirements of many scenarios such as consumption and industry. The setting of the conical lens can reduce the divergence angle of the detection light and the echo light, reduce the aberration defects in the detection light and the echo light, so that the ranging capability of the laser radar can meet the use requirements. In addition, the laser radar provided by the embodiment of the present application can abandon the overall rotation scanning scheme and only use a single scanning module, while the other components are fixedly arranged, which can make the overall architecture of the laser radar simple and highly reliable. The laser radar provided in the embodiments of the present application can be widely used in robotics, industrial automation, logistics, self-driving taxis, surveying and inspection, and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] FIG1 is a schematic diagram of the structure of a laser radar provided in one embodiment of the present application, in which the solid arrows indicate the propagation direction of the detection light, and the dotted arrows indicate the propagation direction of the return light;

[0033] FIG2 is a schematic diagram of the structure of a laser radar provided in another embodiment of the present application, in which the solid arrows represent the propagation direction of the detection light, and the dotted arrows represent the propagation direction of the return light;

[0034] FIG3 is a schematic diagram of a concentric circle scanning pattern formed by a scanning module in a laser radar provided by an embodiment of the present application;

[0035] FIG4 is a schematic diagram of the propagation direction of the detection light before and after reflection by the conical reflector in the laser radar provided by an embodiment of the present application, wherein the solid arrow in the figure indicates the propagation direction of the detection light;

[0036] FIG5 is a schematic diagram of the structure of a cylindrical mirror in a laser radar provided in one embodiment of the present application;

[0037] FIG6 is a schematic diagram of the structure of a cylindrical mirror in a laser radar provided in another embodiment of the present application;

[0038] FIG7 is a schematic diagram of the structure of a cylindrical mirror in a laser radar provided in another embodiment of the present application;

[0039] FIG8 is a schematic diagram of the structure of a laser radar provided in another embodiment of the present application, in which the solid arrows represent the propagation direction of the detection light, and the dotted arrows represent the propagation direction of the echo light;

[0040] FIG9 is a schematic diagram of the structure of an angle-expanding lens assembly in a laser radar according to an embodiment of the present application, wherein the solid arrow in the figure indicates the propagation direction of the detection light;

[0041] FIG10 is a schematic diagram of the structure of an angle-expanding lens assembly in a laser radar provided in another embodiment of the present application, wherein the solid arrow in the figure indicates the propagation direction of the detection light;

[0042] FIG11 is a schematic diagram of the structure of a laser radar provided in another embodiment of the present application, in which the solid arrows represent the propagation direction of the detection light, and the dotted arrows represent the propagation direction of the echo light;

[0043] FIG12 is a schematic diagram showing how deformation of a scanning trajectory changes with scanning angle when a laser radar according to an embodiment of the present application is used for detection;

[0044] Figure 13 is a structural schematic diagram of a conical lens and a conical reflector used in a laser radar provided in another embodiment of the present application. The solid arrow in the figure indicates the propagation direction of the detection light.

[0045] Description of reference numerals:

[0046] 100. Transceiver module; 111. Light source; 112. Collimating lens; 120. Receiving module; 121. Reflecting element; 122. Detection component; 130. Spectrometer module; 140. Cylindrical mirror; 141. Optical substrate; 142. Electrolyte; 143. Oily non-polar substance; 144. Cylindrical lens; 145. Liquid crystal layer; 146. Liquid crystal substrate glass; 147. Substrate; 148. Metasurface; 149. Adjustable material layer; 150. Transparent electrode layer; 200. Scanning module; 300. Conical lens; 400. Conical reflector; 410. Conical surface; 500. Angle expansion lens group; 510. Convex lens; 520. Concave lens; α1. Cone angle of conical lens; α2. Cone angle of conical reflector. Modes for Carrying Out the Invention

[0047] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit this application.

[0048] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0049] In order to illustrate the technical solution provided by this application, a detailed description is given below with reference to specific drawings and embodiments.

[0050] Referring to Figure 1 , an embodiment of the present application provides a laser radar. The laser radar includes a transceiver module 100, a scanning module 200, a conical lens 300, and a conical reflector 400, which are sequentially arranged along the direction of emission of detection light. The tips of the conical lens 300 and the conical reflector 400 are positioned opposite each other, with their optical axes co-aligned.

[0051] The transceiver module 100 is used to provide probe light and also to receive and process echo light. The transceiver module 100 in this embodiment may, depending on the application, include only a laser and a detector, where the laser is used to provide probe light and the detector is used to receive and process echo light. Alternatively, it may include a laser, a detector, and other optical components, where the optical components may be at least one or more of a collimating lens, a reflective element, and the like, depending on the specific application. A laser and a detector form a transceiver pair, and the transceiver module 100 may include one or more transceiver pairs.

[0052] The scanning module 200 is used to change the propagation direction of the detection light and the echo light. The scanning module 200 can use a galvanometer, a rotating mirror or other scanning devices according to the use requirements. The scanning module 200 can realize two-dimensional scanning of the detection light.

[0053] The conical lens 300 is used to allow the detection light and the echo light to pass through and is also used to correct the detection light and the echo light. The conical lens 300 can be a cone structure with at least one conical surface, a frustum structure, or an irregular structure, and the specific structure can be selected according to the specific application needs. The tip of the conical surface of the conical lens 300 faces the conical reflector 400, that is, away from the scanning module 200. The conical lens 300 can reduce the divergence angle of the detection light and the echo light and correct light aberrations.

[0054] Conical reflector 400 is used to reflect the detection light and the return light. Conical reflector 400 can be a cone, a frustum, or an irregular structure with at least one conical surface. The specific structure can be selected based on the actual use. The tip of the conical surface of conical reflector 400 faces conical lens 300.

[0055] The detection light can pass through the scanning module 200, the conical lens 300, and the conical reflector 400 in sequence to irradiate the target area, and be reflected by the obstacles in the target area to form echo light; the echo light can pass through the conical reflector 400, the conical lens 300, and the scanning module 200 in sequence, and finally be received and processed by the transceiver module 100.

[0056] The working principle of the laser radar provided in this embodiment is as follows:

[0057] When the target area needs to be detected, the transceiver module 100 sends out a detection light. The detection light first passes through the scanning module 200 to change the propagation direction to form a scanning light, then passes through the conical lens 300 to reduce the divergence angle, and is reflected by the conical reflector 400 to irradiate the target area.

[0058] During the above process, because the scanning module 200 can change the propagation direction of the probe light, two-dimensional scanning is achieved. Specifically, the scanning module 200 can form a concentric circular scanning pattern as shown in FIG3 . Therefore, the scanning light can be irradiated onto different positions on the same circumference of the conical lens 300, and further onto different positions on the same circumference of the conical reflector 400, performing 360° detection, as shown in FIG4 . Furthermore, because the scanning module 200 can change the propagation direction of the probe light, the scanning light can be irradiated onto different positions along the generatrix of the conical lens 300, so that the probe light emitted by the conical reflector 400 forms a concentric circular spot trajectory.

[0059] After the detection light is irradiated into the target area, if there is an obstacle in the target area, the detection light will be reflected by the obstacle to form an echo light. The echo light can first be reflected by the conical reflector 400, then irradiated by the conical lens 300, and then passed through the conical lens 300. After being corrected by the conical lens 300, it is irradiated by the scanning module 200. The scanning module 200 then changes the propagation direction and reaches the transceiver module 100. Finally, the transceiver module 100 receives and processes the light, and then transmits the corresponding digital signal to the outside for reception and processing by the external signal processing device, and then obtains the corresponding detection result.

[0060] The conical reflector 400 is designed to project the concentric circular light spot trajectory into a multi-layer circular scan (as shown in Figure 4), achieving a scanning effect equivalent to or comparable to that of a multi-line LiDAR. Compared to a flat reflector, the conical reflector 400 has a curved surface. This curvature scatters the light spot into an elongated strip, causing it to diffuse and severely impact the LiDAR's ranging performance. Therefore, a conical lens 300 is required to compensate for this diffuse light spot.

[0061] The conical surfaces of the conical reflector 400 and the conical lens 300 can be simulated using optical simulation software, allowing them to effectively compensate for each other. Furthermore, by properly setting the spacing between the conical reflector 400 and the conical lens 300, the detection light can achieve a beam expansion effect when passing through the conical reflector 400 and the conical lens 300. This allows the detection light to not only achieve spot shaping but also increase the scanning angle when passing through the conical reflector 400 and the conical lens 300. For example, with an exit angle of ±9.5 degrees, the scanning angle can reach 34 degrees after passing through the two conical elements.

[0062] During the entire process, the setting of the conical reflector 400 can cooperate with the scanning module 200 to achieve 360° detection. However, since the reflective surface of the conical reflector 400 is a curved surface, scattering occurs after the light is reflected by it, making the size of the light spot irradiated to the target area larger, affecting the ranging capability of the laser radar. The setting of the conical lens 300 can, on the one hand, reduce the angle of the detection light before it reaches the conical reflector 400, and can also reduce the aberration defects in the detection light to a certain extent, thereby reducing the size of the light spot corresponding to the light emitted outward after the detection light passes through the conical reflector 400, and to a certain extent reduce the aberration and light spot dispersion of the detection light emitted by the laser radar; on the other hand, it can also reduce the angle of the detection light, and can also reduce the aberration defects in the echo light to a certain extent, thereby making the size of the scanning device smaller, and can also improve the imaging quality of the laser radar itself or the imaging quality of the external signal processing device connected to the laser radar to a certain extent.

[0063] These aberrations refer to discrepancies between the results obtained by tracing non-paraxial and paraxial rays in actual optical systems, and these deviations from the ideal conditions of Gaussian optics (first approximation theory or paraxial rays). These aberration defects include, but are not limited to, spherical aberration, coma, astigmatism, field curvature, and distortion.

[0064] The laser radar provided in the embodiment of the present application includes a transceiver module 100, a scanning module 200, a conical lens 300 and a conical reflector 400, which are arranged in sequence along the emission direction of the detection light. The conical lens 300 and the tip of the conical reflector 400 are arranged relative to each other and the optical axes of the two are located on the same straight line. The setting of the conical reflector 400 can cooperate with the scanning module 200 to achieve 360° multi-line detection, so that the laser radar can use one or more transceiver pairs to achieve multi-line scanning. There is no linear correlation between the number of lines and the number of transceiver pairs. This can reduce the number of transceiver pairs required in the transceiver module 100 in the laser radar, thereby reducing the production cost of the transceiver module 100 and the laser radar, and can adapt to the cost requirements of many scenarios such as consumption and industry. The setting of the conical lens 300 can reduce the divergence angle of the detection light and the echo light, reduce the aberration defects in the detection light and the echo light, and thus make the ranging capability of the laser radar meet the use requirements. Furthermore, the laser radar provided by the embodiments of the present application can abandon the overall rotating scanning solution and only use a single scanning module 200, while other components are fixed, which can make the overall architecture of the laser radar simple and highly reliable. The laser radar provided by the embodiments of the present application can be widely used in robotics, industrial automation, logistics, self-driving taxis, surveying and inspection, and other fields.

[0065] As shown in FIG1 , in some embodiments, the transceiver module 100 includes a light source 111, a collimating lens 112, a receiving module 120, and a spectrometer module 130. The collimating lens 112 is located on the light-emitting side of the light source 111. The spectrometer module 130 is located on the light-emitting side of the light source 111, and the receiving module 120 is located on the light-emitting side of the spectrometer module 130.

[0066] The light source 111 is used to provide detection light. The light source 111 in this embodiment may include one or more lasers, which can be specifically set according to the needs of use. The collimating lens 112 in this embodiment may include one or more lenses for collimating the detection light. The collimating lens 112 can adopt a spherical lens or an aspherical lens, which can be specifically set according to the needs of use. It should be noted that the detection light can form a parallel beam or not form a parallel beam after passing through the collimating lens. In either case, the divergence angle of the detection light will be reduced.

[0067] The receiving module 120 is used to receive and process the echo light. The receiving module 120 in this embodiment may include one or more detectors, and may also include a detector and a reflective optical component, which can be configured based on usage requirements. When the receiving module 120 includes a detector and a reflective optical component, the reflective optical component may include one or more reflective elements, and may also include other optical elements for light shaping, which can be configured based on usage requirements. The reflective optical component can be used to change the propagation direction of the echo light so that the echo light can be irradiated onto the detector and thereby received by the detector. The detector is used to receive the echo light reflected by the reflective optical component, process the echo light, convert the light into an electrical signal, and output it.

[0068] The spectrometer module 130 is used to allow one of the detection light and the echo light to pass through and reflect the other light. Exemplarily, the spectrometer module 130 can split the detection light and the echo light by deflection or transmission. For example, in Figure 1, the spectrometer module 130 allows the detection light to pass through and deflects (e.g., reflects) the echo light before transmitting it. In other embodiments, the laser radar can also be configured so that the spectrometer module 130 deflects the received detection light and then transmits it, allowing the received echo light to pass through.

[0069] The transceiver module 100 provided in this embodiment has a simple structure and adopts a coaxial setting, which allows the transmitting optical path and the receiving optical path to share the same scanning module 200, conical lens 300 and conical reflector 400 to complete three-dimensional imaging, thereby reducing the number of components required for the laser radar and reducing the cost.

[0070] In some embodiments, the collimating lens 112 may be an aspheric lens, so that the collimating lens 112 can have a better curvature radius, maintain good aberration correction and higher resolution, and can be smaller than a collimating lens 112 using a spherical lens.

[0071] In one specific embodiment, the light source uses a 905nm semiconductor laser, one of the most mature wavelengths for laser ranging, with a stable and mature supply chain. After passing through an aspheric collimating lens, the beam divergence angle can reach 3mrad to 5mrad along one axis and 8mrad to 10mrad along the other.

[0072] As shown in FIG1 , in some embodiments, the receiving module 120 includes a reflective element 121 and a detection assembly 122, which are sequentially arranged along the propagation direction of the echo light. The reflective element 121 is used to reflect the echo light transmitted by the scanning module 200. The detection assembly 122 is used to receive the echo light reflected by the reflective element 121 and process the echo light.

[0073] The reflective element 121 is an optical element that operates according to the law of reflection and can be one or more reflective mirrors, or other reflective optical elements (such as reflective paper, reflective sheet, etc.). The reflective mirrors can be plane mirrors, spherical mirrors, or aspherical mirrors, depending on the application needs. A fully reflective mirror is generally used.

[0074] The detection assembly 122 may include one or more detectors according to the use requirements. In addition, the detection assembly 122 may also include a circuit board for supporting the detectors, etc., which may be specifically set according to the use requirements.

[0075] The receiving module 120 adopts the structure provided in this embodiment, which has a simple structure and can enable the detection component 122 and the light source to be arranged in parallel, so that the volume of the transceiver module 100 is relatively small.

[0076] In addition, in current multi-line LiDARs, the number of channels in the stacked transceiver pairs and signal processing circuits is consistent with the number of lines. For example, a 16-line LiDAR contains 16 transceiver units and signal processing circuits. This technical feature causes the material cost to increase proportionally with the number of lines, and the production process assembly costs and subsequent use costs are also high. However, in the LiDAR provided in this embodiment, only one or several transceiver pairs can be provided, thereby reducing the price of the LiDAR.

[0077] As shown in Figure 1, in an optional embodiment, the reflective element 121 includes a plane reflector. With this structure, the reflective element 121 has a simple structure and is easy to assemble.

[0078] As shown in Figure 2, in some embodiments, the transceiver module further includes a cylindrical mirror 140 located between the light source 111 and the light splitting module 130. The cylindrical mirror 140 is used to allow the detection light to pass through, so as to cooperate with the conical lens 300 to correct the detection light.

[0079] The cylindrical mirror 140 located between the light source 111 and the spectrometer module 130 means that the cylindrical mirror 140 can be located between the light source 111 and the collimating lens 112, or between the collimating lens 112 and the spectrometer module 130. When the collimating lens 112 has multiple lenses, the cylindrical mirror 140 can also be located between different lenses of the collimating lens 112, which can be specifically set according to usage needs.

[0080] Since the smaller the diameter of the conical reflector 400, the smaller the radius of curvature, the greater the accompanying optical distortion. However, large distortion is not the most fatal. For vertical scanning, at different vertical scanning angles, the corresponding curvature radius is different at different positions of the conical reflector 400. In this case, the relatively arranged conical reflector 400 and the conical lens 300 cannot ensure that the light spot obtains the optimal spot quality at all vertical angles. Therefore, we need to introduce a cylindrical mirror 140 to further compensate the detection light before the detection light enters the scanning module 200.

[0081] The cylindrical mirror 140 is an aspheric lens, which can effectively reduce the spherical aberration of the detection light. According to the needs of use, any one of the following can be used: a plano-convex cylindrical lens, a plano-concave cylindrical lens, a double-convex cylindrical lens, a double-concave cylinder, a meniscus cylindrical mirror, a cylindrical-intersecting cylindrical mirror and an irregular cylindrical lens.

[0082] The main function of the cylindrical mirror 140 in this embodiment is to compensate for the divergence of the light spot caused by the subsequent conical lens 300 and the conical reflector 400 due to the presence of their own conical surfaces. Specifically, the cylindrical mirror 140 can cooperate with the conical lens 300 to correct the detection light. For example, at certain scanning angles, when the cylindrical mirror 140 is not provided, the light emitted by the conical lens 300 and the conical reflector 400 is not good, and a cylindrical mirror 140 with a converging function is required to correct it. In this case, the cylindrical mirror 140 can adopt any structure with a positive optical focal length, or the specific structure of the cylindrical mirror 140 can be determined based on testing or simulation; if a cylindrical mirror 140 with a diverging function is required to correct it, then the cylindrical mirror 140 can adopt any structure with a negative optical focal length, or the specific structure of the cylindrical mirror 140 can be determined based on testing or simulation.

[0083] The use of the laser radar provided in this embodiment can further reduce the aberration defects of the detection light emitted by the laser radar and improve the ranging capability of the laser radar.

[0084] The cylindrical mirror 140 can be positioned in various locations depending on the application. For example, in some embodiments, the cylindrical mirror 140 is located between the collimating lens 112 and the spectrometer module 130. In other embodiments, multiple collimating lenses 112 are provided, and the cylindrical mirror 140 is located between the multiple collimating lenses 112. Regardless of the location, the cylindrical mirror 140 can be used in conjunction with the conical lens to correct the detection light. The specific location can be determined based on the laser radar's emitted light spot size and detection performance.

[0085] The cylindrical mirror 140 can adopt a fixed structure in which the equivalent radius of curvature of both the light-emitting surface and the light-entering surface is fixed, or it can adopt a variable structure in which at least one of the equivalent radius of curvature of the light-emitting surface and the light-entering surface is variable. In the case where the size of the conical reflector 400 and the conical lens 300 is limited by the overall size requirements of the product (for example, in a small-sized lidar product, the diameter of the conical lens 300 and the conical reflector 400 is required to be no more than 80 mm), the cylindrical mirror 140 adopts a fixed structure and cannot obtain consistent light spot quality at all angles. To alleviate this problem, in some embodiments, the equivalent radius of curvature of the light-entering surface and / or the light-emitting surface of the cylindrical mirror 140 is adjustable. The above-mentioned adjustable equivalent radius of curvature includes but is not limited to the following situations:

[0086] The first is that the actual curvature radius of the light incident surface and the light emitting surface of the cylindrical mirror 140 does not change, but the refractive index of the cylindrical mirror 140 changes, such as a liquid crystal lens. At this time, the light emitting effect through the cylindrical mirror 140 changes, and it can be considered that the equivalent curvature radius of the light incident surface and / or light emitting surface of the cylindrical mirror 140 has changed.

[0087] The second type is that the actual curvature radius of the light incident surface and / or the light exit surface of the cylindrical mirror 140 changes, and the light exiting effect through the cylindrical mirror 140 changes. At this time, the actual curvature radius of the light incident surface and / or the light exit surface of the cylindrical mirror 140 is the equivalent curvature radius of the corresponding surface.

[0088] When in use, the use status of the cylindrical mirror 140 can be adjusted according to the scanning angle, that is, the equivalent curvature radius of the light incident surface and / or the light exit surface of the cylindrical mirror can be adjusted, so that the cylindrical mirror 140 and the conical lens 300 can be matched to make the aberration of the detection light emitted by the laser radar smaller and the spot size smaller, so as to meet the detection needs under different scanning angles.

[0089] By using the laser radar provided in this embodiment, the laser radar can obtain relatively consistent spot quality at different scanning angles, and the detection effect can meet the preset requirements, which can broaden the scope of application of the laser radar.

[0090] To ensure that the laser radar's spot quality meets preset requirements at all vertical scanning angles, the equivalent radius of curvature can be anywhere from -200 mm to 200 mm, as determined by the scanning angle and the structures of the conical lens 300 and conical reflector 400.

[0091] In some optional embodiments, the equivalent radius of curvature can be any value between -70 mm and 200 mm, so that the spot quality of the laser radar meets the preset requirements at all vertical scanning angles.

[0092] The cylindrical lens 140 may be a liquid zoom lens, a liquid crystal lens, or an adjustable metasurface lens.

[0093] A liquid zoom lens is an optical element that can adjust its focal length by changing its shape. It consists of a layer of liquid, typically a transparent dielectric material such as silicone or polymer. Liquid zoom lenses use external stimuli such as electric fields, pressure, or sound waves to change the shape of the liquid, thereby altering the path of light through the lens and its focus. Liquid zoom lenses offer the following advantages over traditional fixed-focal-length lenses: 1. Adjustable focal length: Liquid zoom lenses enable continuous and stepless focus adjustment without the need for mechanical lens movement or replacement of lenses with different focal lengths. This makes liquid zoom lenses more flexible and convenient for a variety of applications. 2. Fast response: Liquid zoom lenses can rapidly adjust their focal length in response to external stimuli, resulting in a relatively fast response speed. This is particularly beneficial for applications requiring frequent or rapid focus adjustments. 3. Small and lightweight: Liquid zoom lenses are more compact and lightweight than traditional mechanical focusing systems, making them suitable for small devices and portable applications. These advantages have led to the large-scale application of liquid lenses in consumer electronics, such as mobile phones. The operating principle of liquid zoom lenses can vary depending on the type of external stimulus. Taking an electric field as an example, when an electric field is applied, the charge distribution within a liquid variable focus lens changes, causing the shape and refractive index of the liquid to change, thereby altering the focal length of the lens. By controlling the magnitude and direction of the electric field, precise control of the focal length can be achieved. Liquid variable focus lenses have a wide range of applications, including photography, medical imaging, laser systems, and autonomous driving. Their flexibility, fast response, and small size and lightness bring new possibilities to these applications. In some embodiments, as shown in Figure 5, the overall shape of the liquid variable focus lens resembles a cylinder. Its upper and lower surfaces are composed of two optical substrates 141 (thin glass sheets). The inner wall of the lens is divided into two layers: one cylindrical and the other frustum-conical. Both layers are composed of metal electrodes. A layer of insulating material is applied between the two electrodes to prevent electrical conduction between them. The container of the liquid variable focus lens is filled with two liquids: an electrolyte 142 and an oily non-polar substance 143. Because they are immiscible, the two liquids will naturally form a clearly visible lens layer at their contact surface, which has a converging effect on light.

[0094] Liquid crystal lenses are optical devices that utilize liquid crystals. They can adjust the focus of light by changing the arrangement of liquid crystal molecules. Liquid crystal lenses typically consist of two parallel glass sheets with a layer of liquid crystal material sandwiched between them. The operating principle of a liquid crystal lens is to apply an electric field to alter the alignment of the liquid crystal molecules, thereby changing the focal length and focusing effect of the lens. Depending on the arrangement of the liquid crystal molecules, liquid crystal lenses can achieve either positive or negative lens effects. A positive lens focuses light toward the center, while a negative lens disperses it. Liquid crystal lenses are widely used in optical systems such as cameras, microscopes, and projectors. They offer the following features: 1. Adjustable focal length: By changing the arrangement of liquid crystal molecules, the focal length can be adjusted, thereby controlling the focus of light. 2. Fast response: Liquid crystal lenses have a fast response speed, capable of adjusting the focal length within milliseconds, making them suitable for real-time adjustment needs. 3. No mechanical movement: Compared to traditional mechanical lenses, liquid crystal lenses require no mechanical movement, eliminating the wear and noise associated with mechanical components. 4. Compact and lightweight: Liquid crystal lenses are compact and lightweight, making them suitable for applications requiring a compact design. 5. Low power consumption: Liquid crystal lenses only require the application of an electric field to alter the arrangement of liquid crystal molecules, resulting in low power consumption. Liquid crystal materials are readily available and inexpensive due to their large-scale industrial application, and the manufacturing process is relatively simple. In some embodiments, as shown in FIG6 , the liquid crystal lens comprises a cylindrical lens 144, a liquid crystal layer 145, and a liquid crystal substrate glass 146, stacked in sequence. During operation, an ITO transparent electrode can be used to power the liquid crystal layer. At different voltages, the equivalent curvature can be adjusted, and even a negative lens can be switched to a positive lens.

[0095] Metasurfaces are an important research topic in planar optics. By arranging subwavelength nanoantennas, equivalent to arbitrary phase delays and phase distribution curves, the effects of complex optical systems can be simulated within an ultra-thin plane. Active metasurfaces, on the other hand, incorporate electrically, temperature-, or light-adjustable materials (such as liquid crystals) onto the surface of nanoantennas. This allows the phase response of the nanoantennas to be altered upon injection of an external stimulus, thereby achieving an adjustable metasurface. In some embodiments, as shown in FIG7 , an adjustable metasurface lens includes a substrate 147, a metasurface 148, an adjustable material layer 149 (such as a liquid crystal material or a phase change material layer), and a transparent electrode layer 150, which are stacked in sequence.

[0096] When in use, a suitable lens can be selected as the cylindrical lens 140 according to the respective characteristics of a liquid zoom lens, a liquid crystal lens, or an adjustable metasurface lens. Regardless of which lens is used, the cylindrical lens 140 can adjust the curvature radius of the deformed surface, and the technology is mature.

[0097] It should be noted that when the transceiver module has both a collimating lens and a cylindrical lens, the cylindrical lens can be located on the light-emitting side of the collimating lens, or between the collimating lens and the light source, or between multiple lenses when the collimating lens has multiple lenses. The specific location can be determined based on the light-emitting effect.

[0098] To alleviate the aforementioned issues, in other embodiments, the cylindrical mirror can be moved between the light source and the spectrometer. This embodiment allows for manual or mechanical adjustment of the cylindrical mirror (e.g., through a linear drive mechanism). This adjustment enables zooming, enabling the LiDAR to achieve relatively consistent light spot quality even when the scanning angle changes, in conjunction with the conical lens and conical reflector.

[0099] As mentioned above, the smaller the diameter of the conical reflector 400, the smaller the radius of curvature, and the greater the accompanying optical distortion. However, large distortion is not the most fatal. For vertical scanning, at different vertical scanning angles, the corresponding curvature radius is different at different positions of the conical reflector 400. In this case, the relatively arranged conical reflector 400 and the conical lens 300 cannot ensure that the light spot obtains the optimal spot quality at all vertical angles. In order to alleviate this problem, in addition to adding a cylindrical mirror 140 as described in the above embodiments, other solutions can also be adopted. As shown in Figure 8, in some embodiments, the laser radar also includes an angle expansion lens group 500. The angle expansion lens group 500 is arranged between the scanning module 200 and the conical lens 300. The angle expansion lens group 500 is used to expand the exit angle of the detection light, and is also used to cooperate with the conical lens 300 to correct the detection light.

[0100] In this embodiment, the angle expansion lens group 500 may include at least one convex lens 510, and may also include a concave lens 520, or other lenses. The specific details can be determined according to the needs of use. There is no sole limitation here. As long as the angle expansion lens group 500 can achieve the expansion of the exit angle of the detection light and the final light spot emitted by the conical reflector 400 can be optimized, it will be sufficient.

[0101] By using the laser radar provided in this embodiment, the emission angle of the detection light can be further increased, thereby increasing the emission field angle of the laser radar, reducing the aberration defects of the detection light emitted by the laser radar, and improving the ranging capability of the laser radar.

[0102] The above-mentioned angle-expanding lens assembly 500 can be configured in various forms according to the needs of use. As shown in Figure 9, in some embodiments, the angle-expanding lens assembly 500 includes at least two convex lenses 510 arranged in sequence along the emission direction of the detection light. As shown in Figure 10, in other embodiments, the angle-expanding lens assembly 500 includes a convex lens 510 and a concave lens 520 arranged in sequence along the emission direction of the detection light. In other embodiments, other forms can also be adopted. The number of lenses in the angle-expanding lens assembly 500 can be two or even more, depending on the specific needs of use.

[0103] When the angle expansion lens assembly 500 includes at least two convex lenses 510 sequentially arranged along the direction of the detection light, a Keplerian-type angle expansion lens assembly is employed. When the angle expansion lens assembly 500 includes a convex lens 510 and a concave lens 520 sequentially arranged along the direction of the detection light, a Galilean-type angle expansion lens assembly is employed. Regardless of the type of angle expansion lens assembly 500 employed, both beam expansion and spot optimization can be achieved, and the specific configuration can be determined based on actual use.

[0104] It should be noted that in order to achieve optimal spot quality at all vertical angles for the light spot emitted by the laser radar, a cylindrical mirror 140 can be optionally installed between the light source 111 and the spectrometer module 130, as shown in FIG2 ; an angle-expanding lens assembly 500 can also be optionally installed between the scanning module 200 and the conical lens 300, as shown in FIG8 ; or an angle-expanding lens assembly 500 can be installed both between the light source 111 and the spectrometer module 130 and between the scanning module 200 and the conical lens 300, as shown in FIG11 . The specific configuration can be determined based on actual use needs. The above-mentioned use needs include but are not limited to the requirements for the emission field of view angle and / or the requirements for the spot size.

[0105] In some embodiments, the scanning module 200 may include at least one of a solid beam deflector, a liquid beam deflector, and a liquid crystal beam deflector. The solid beam deflector may include at least one of a MEMS (Micro-Electro-Mechanical System) mirror, a scanning prism, a spatial light modulator (SLM), and an optical phased array (OPA), or may include a mirror and a drive mechanism for rotating the mirror, such as a voice coil motor (VCM) or a mechanical motor. The liquid beam deflector may include a liquid mirror or a liquid prism driven by electrowetting, dielectrophoresis, or a mechanical motor.

[0106] As shown in FIG1 , in some embodiments, the cone angle α1 of the conical lens 300 is 40° to 120°, and the cone angle α2 of the conical reflector 400 is 40° to 120°. That is, the cone angle α1 of the conical lens 300 is within the range of 40° to 120°, and the cone angle α2 of the conical reflector 400 is also within the range of 40° to 120°.

[0107] The cone angle α1 of the conical lens 300 refers to the angle between two generatrixes of an axial cross section of the conical lens 300 (a cross section passing through the axis of the conical surface).

[0108] The cone angle α2 of the conical reflecting mirror 400 refers to the angle between two generatrixes of an axial cross section of the conical reflecting mirror 400 (a cross section passing through the axis of the conical surface).

[0109] Because height is directly related to the physical angle of the cone (the angle between the oblique line of the cone section and the ground), the angle of the conical lens 300 cannot be too large to account for factors such as total internal reflection (based on the lens's refractive index, glass or plastic with a refractive index of approximately 1.4 is typically used. To avoid total internal reflection, the cone angle is usually required to be less than 45 degrees or even smaller). For the conical reflector 400, too small a cone angle will inevitably result in insufficient system output angle coverage, so a larger angle is usually required. The cone angle of the conical lens 300 is between 40° and 120°, and the cone angle of the conical reflector 400 is also between 40° and 120°, allowing the lidar to meet general detection needs.

[0110] The conical surface 410 on the conical lens 300 and conical reflector 400 can be a conical surface 410 with a constant cone angle, or it can be composed of multiple conical surfaces 410. In some cases, we require a vertical field of view covering a wider range, up to 60 degrees. In this case, if the conical reflector and conical lens 300 use conical surfaces with a single angle, the scanning angle requirements of the scanning module 200 will be greatly increased. Regardless of the architecture of the scanning module 200, large-angle scanning is very challenging and usually requires compromising key parameters such as scanning speed. To increase the detection field of view of the lidar, as shown in Figure 13, in some embodiments, the conical reflector 400 and conical lens 300 each include multiple conical surfaces 410. That is, the conical reflector 400 includes multiple conical surfaces 410, and the conical lens 300 also includes multiple conical surfaces 410. In the same mirror body, the cone angle of all conical surfaces 410 decreases from the tip to the other end of the mirror body. That is, the cone angles of all conical surfaces 410 in conical reflector 400 decrease sequentially from the tip of conical reflector 400 to the other end (i.e., the end where the bottom surface of conical reflector 400 is located). The cone angles of all conical surfaces 410 in conical lens 300 decrease sequentially from the tip of conical lens 300 to the other end (i.e., the end where the bottom surface of conical lens 300 is located). It should be understood that all of the conical surfaces described above refer to the optical surfaces used to receive detection light and echo light. Any other conical surfaces in conical reflector 400 and conical lens 300 are not included in the scope of these conical surfaces.

[0111] The laser radar provided in this embodiment uses a single conical surface 410 compared to the conical lens 300 and the conical reflector 400, so that the detection field angle of the laser radar can be larger.

[0112] As shown in FIG13 , in some embodiments, the conical reflector 400 and the conical lens 300 each include three conical surfaces 410. That is, the conical reflector 400 includes three conical surfaces 410, and the conical lens 300 also includes three conical surfaces 410. In the same mirror body, the cone angles of the multiple conical surfaces 410 decrease sequentially from the tip to the other end of the mirror body, and the cone angle of each conical surface is within a preset range. The preset range is 40° to 120°. That is, the cone angles of the three conical surfaces 410 in the conical reflector 400 decrease sequentially from the tip to the other end (i.e., the end where the bottom surface of the conical reflector 400 is located), and the cone angle of each conical surface is within a preset range, which is 40° to 120°. The cone angles of the three conical surfaces 410 in the conical lens 300 decrease successively from the tip of the conical lens 300 to the other end (i.e., the end where the bottom surface of the conical lens 300 is located), and the cone angle of each conical surface is within a preset range, which is 40°~120°.

[0113] In this way, when the scanning angle of the scanning module 200 remains unchanged (±10 degrees), the laser radar provided in this embodiment can achieve a detection field angle of 58 degrees, meeting general detection needs.

[0114] For ease of understanding, the working principle of the laser radar provided in this application is described using a specific embodiment shown in FIG2 .

[0115] In this embodiment, the laser radar includes a transceiver module 100, a scanning module 200, a conical lens 300, and a conical reflector 400, arranged sequentially along the direction of the detection light. The tips of the conical lens 300 and conical reflector 400 are positioned opposite each other, with their optical axes aligned. The transceiver module 100 includes a light source 111, a cylindrical mirror 140, a receiving module 120, and a spectrometer module 130.

[0116] The light source uses a 905nm semiconductor laser. The cylindrical mirror 140 has a flat light-entry surface and an adjustable effective radius of curvature on the light-exit surface. Cylindrical mirror 140 utilizes a liquid lens. The scanning module 200 consists of a reflector and a voice coil motor that drives the reflector. The voice coil motor enables 320Hz dual-axis scanning and incorporates Hall sensors for closed-loop scanning control, resulting in a field of view (FOV) of ±10 degrees. The motor scanning angle corresponds to the scanning angle of the optical axis. For in-plane scanning, the laser scanning angle is doubled, or ±20 degrees. However, for vertical scanning, the resulting laser scanning angle is smaller than in the other dimension because the plane of the optical axis and the incident light spot constantly changes during the scanning process. At 45-degree incidence, the field of view is reduced by up to 30% due to distortion, meaning that the vertical scanning angle is only approximately ±14 degrees. As shown in Figure 12, the scanning curve changes under different incident angles. When the incident angle is 90 degrees, the scanning trajectory is a perfect straight line. However, when the incident angle offset is larger, the deformation amount is larger, and the scanning angle also becomes smaller.

[0117] After the light source emits probe light, it is shaped by cylindrical mirror 140 and then strikes scanning module 200 at a 45-degree angle of incidence (the angle in the non-powered scanning state). Scanning module 200 produces a concentric circle pattern: 16 concentric circles correspond to 16 laser radar lines, and 32 lines correspond to 32 concentric circle scanning patterns. After the concentric circle laser pattern is scanned, it is projected onto conical lens 300 and conical reflector 400. In this embodiment, conical lens 300 and conical reflector 400 are designed with symmetrical dimensions: a base diameter of 50 mm, a reflector height of 25 mm, and a lens height of 20 mm. It should be noted that for ease of device processing, the conical tip can be flattened to a rounded shape without affecting the overall surface shape. Conical reflector 400 is precision CNC-finished metal with an aluminum or silver coating, while conical lens 300 is made of K9 glass. After passing through two symmetrically placed conical elements, the laser spot achieves a scanning angle of 34 degrees in the vertical direction, thereby achieving the completely equivalent effect of a multi-line lidar.

[0118] The above are merely optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A laser radar, characterized in that: It comprises a transceiver module (100), a scanning module (200), a conical lens (300) and a conical reflector (400) which are sequentially arranged along the emission direction of the detection light, wherein the tips of the conical lens (300) and the conical reflector (400) are arranged opposite to each other and the optical axes of the two are located on the same straight line; The transceiver module (100) is used to provide detection light and also to receive and process echo light; The scanning module (200) is used to change the propagation direction of the detection light and the echo light; The conical lens (300) is used for allowing the detection light and the echo light to pass through, and is also used for correcting the detection light and the echo light; The conical reflector (400) is used to reflect the detection light and the echo light; The detection light can sequentially pass through the scanning module (200), the conical lens (300), and the conical reflector (400) to irradiate into the target area, and be reflected by obstacles in the target area to form the echo light. The echo light can sequentially pass through the conical reflector (400), the conical lens (300), and the scanning module (200), and finally be received and processed by the transceiver module (100).

2. The laser radar according to claim 1, characterized in that The transceiver module (100) comprises a light source (111), a collimating lens (112), a receiving module (120) and a light splitting module (130), wherein the collimating lens (112) is located on the light output side of the light source (111), the light splitting module (130) is located on the light output side of the collimating lens (112), and the receiving module (120) is located on the light output side of the light splitting module (130); The light source (111) is used to provide the detection light; The collimating lens (112) is used to collimate the detection light; The receiving module (120) is used to receive and process the echo light; The light splitting module (130) is used to allow one of the detection light and the echo light to pass through, and to reflect the other light.

3. The laser radar according to claim 2, characterized in that The transceiver module (100) further comprises a cylindrical mirror (140) located between the light source (111) and the light splitting module (130), wherein the cylindrical mirror (140) is used to allow the detection light to pass through so as to cooperate with the conical lens (300) to correct the detection light.

4. The laser radar according to claim 3, characterized in that The cylindrical mirror (140) is located between the collimating lens (112) and the light splitting module (130); Alternatively, a plurality of collimating lenses (112) are provided, and the cylindrical mirror (140) is located between the plurality of collimating lenses (112).

5. The laser radar as claimed in claim 3, characterized in that The equivalent curvature radius of the light incident surface and / or the light emitting surface of the cylindrical mirror (140) is adjustable.

6. The laser radar according to claim 5, characterized in that The equivalent radius of curvature is -200 mm to 200 mm.

7. The laser radar according to claim 5, characterized in that The equivalent radius of curvature is -70 mm to 200 mm.

8. The laser radar as claimed in claim 5, characterized in that The cylindrical lens (140) is a liquid zoom lens, a liquid crystal lens or an adjustable metasurface lens.

9. The laser radar as claimed in claim 3, characterized in that The position of the cylindrical mirror (140) can be moved between the light source (111) and the light splitting module (130).

10. The laser radar according to any one of claims 1 to 9, characterized in that: The laser radar further comprises an angle-expanding lens group (500), wherein the angle-expanding lens group (500) is arranged between the scanning module (200) and the conical lens (300), and the angle-expanding lens group (500) is used to expand the emission angle of the detection light, and is also used to cooperate with the conical lens (300) to correct the detection light.

11. The laser radar according to claim 10, characterized in that The angle-expanding lens group (500) comprises at least two convex lenses (510) arranged in sequence along the emission direction of the detection light; Alternatively, the angle expansion lens group (500) comprises a convex lens (510) and a concave lens (520) which are sequentially arranged along the emission direction of the detection light.

12. The laser radar according to any one of claims 2 to 9, characterized in that: The collimating lens (112) is an aspherical lens.

13. The laser radar according to any one of claims 2 to 9, characterized in that: The receiving module (120) comprises a reflecting element (121) and a detecting component (122) which are sequentially arranged along the propagation direction of the echo light; the reflecting element (121) is used to reflect the echo light transmitted by the scanning module (200); and the detecting component (122) is used to receive the echo light reflected by the reflecting element (121) and process the echo light.

14. The laser radar according to any one of claims 1 to 9, characterized in that: The scanning module (200) includes at least one beam deflector selected from the group consisting of a solid beam deflector, a liquid beam deflector and a liquid crystal beam deflector.

15. The laser radar according to any one of claims 1 to 9, characterized in that: The cone angle (α1) of the conical lens is 40° to 120°, and the cone angle (α2) of the conical reflector is 40° to 120°.

16. The laser radar according to any one of claims 1 to 9, characterized in that: The conical reflector (400) includes a plurality of conical surfaces (410), and the conical lens (300) also includes a plurality of conical surfaces (410); In the same mirror body, the cone angles of all the conical surfaces (410) decrease successively from the tip of the mirror body to the other end.

17. The laser radar according to any one of claims 1 to 9, characterized in that: The conical reflector (400) includes three conical surfaces (410), and the conical lens (300) also includes three conical surfaces (410); In the same mirror body, the cone angles of the three conical surfaces (410) decrease in sequence from the tip of the mirror body to the other end, and the cone angle of each conical surface (410) is within a preset range, which is 40° to 120°.

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