Lidar

Abstract

The application provides a laser radar, which comprises a transmitting device and at least two receiving devices; the transmitting device comprises a laser transmitting plate, a microlens assembly and a microlens prism assembly, the laser transmitting plate emits laser to a to-be-measured object, the microlens assembly is used for collimating the laser to the microlens prism assembly, and the microlens prism assembly is used for diverging the collimated laser; the at least two receiving devices are arranged on the two sides of the transmitting device respectively, and each receiving device comprises a laser receiving plate, a lens group and an angle expander group, and the laser reflected by the to-be-measured object is sequentially converged to the laser receiving plate through the angle expander group and the lens group. By arranging the at least two receiving devices on the two sides of the transmitting device, the at least two receiving devices can receive the laser reflected by the to-be-measured object, so that the laser radar has an extremely large received pitch field angle range, and the pitch field angle range of the laser radar is improved, and the measurement range of the laser radar is increased.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and more particularly to a lidar. Background Technology

[0002] With the development and application of lidar technology, the market demand for lidar with a large elevation field of view is increasing. However, the elevation field of view of the receiving device of the lidar currently on the market is not large, that is, the receiving range of the receiving device is small. This means that laser light at certain angles cannot be received, thus limiting the elevation field of view range of the lidar, and consequently limiting the measurement range of the lidar. Utility Model Content

[0003] The main objective of this application is to provide a lidar with an ultra-large receiving pitch field of view, thereby increasing the pitch field of view range of the lidar.

[0004] This application provides a lidar system, which includes:

[0005] The emitting device includes a laser emitting plate, a microlens assembly, and a microprism assembly. The laser emitting plate emits a laser beam toward the object under test. The microlens assembly is used to collide the laser beam with the microprism assembly, and the microprism assembly is used to diverge the collimated laser beam.

[0006] At least two receiving devices are respectively disposed on both sides of the transmitting device. Each receiving device includes a laser receiving plate, a lens group, and a wide-angle lens group. The laser reflected back by the object under test is converged onto the laser receiving plate by the wide-angle lens group and the lens group in sequence.

[0007] In one embodiment, at least two of the receiving devices are symmetrically arranged about the transmitting device.

[0008] In one embodiment, the laser emitting plate includes at least one light-emitting unit for emitting the laser;

[0009] The microlens assembly includes at least one microlens array, wherein the microlenses in the microlens array correspond to the light-emitting unit, the light-emitting unit is located at the focal point of the microlens, and the microlens array is used to collimate the laser emitted by the light-emitting unit;

[0010] The microprism assembly includes a light-transmitting substrate and a microprism array formed on a surface of the light-transmitting substrate away from the microlens assembly. The microprism array includes reflective microprisms and refractive microprisms. The reflective microprisms are disposed near the edge of the light-transmitting substrate, and the refractive microprisms are disposed near the center of the light-transmitting substrate. The microprisms in the microprism array correspond to the microlenses in the microlens array.

[0011] In one embodiment, the tilt angle of the reflective microprism increases sequentially from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, and the tilt angle of the reflective microprism is greater than or equal to the critical refraction angle of the reflective microprism, wherein the tilt angle of the reflective microprism is the angle between the inclined surface of the reflective microprism and the surface of the light-transmitting substrate.

[0012] In one embodiment, the tilt angle of the refractive microprism decreases sequentially from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, wherein the tilt angle of the refractive microprism is the angle between the inclined surface of the refractive microprism and the surface of the light-transmitting substrate.

[0013] In one embodiment, in the microlens assembly, at least one of the microlenses does not correspond to the microprisms in the microprism array but corresponds to the direct-lighting area of ​​the light-transmitting substrate, so that the collimated laser directly passes through the direct-lighting area and is emitted directly.

[0014] In one embodiment, the direct-light region is located near the center of the light-transmitting substrate, and the reflective microprism and the refractive microprism are symmetrically arranged about the direct-light region.

[0015] In one embodiment, the inclined surface of the reflective microprism is coated with an internal reflective film, and the inclined surface of the refractive microprism is coated with an antireflective film.

[0016] In one embodiment, the expanding lens group includes a first expanding lens and a second expanding lens. The laser reflected back by the object under test passes sequentially through the first expanding lens and the second expanding lens before being directed towards the lens group. The radius of curvature of the surface of the first expanding lens facing the second expanding lens is smaller than the radius of curvature of the surface facing the object under test, and both are positive values. The radius of curvature of the surface of the second expanding lens facing the lens group is smaller than the radius of curvature of the surface facing the first expanding lens, and both are positive values.

[0017] In one embodiment, the lens group includes a first lens, a second lens, and a third lens; the laser beam converged by the expanding lens group passes sequentially through the first lens, the second lens, and the third lens before being incident on the laser receiving plate; wherein, the radius of curvature of the surface of the first lens facing the second lens is negative, and the radius of curvature of the surface of the first lens facing the expanding lens group is positive; the radius of curvature of the surface of the second lens facing the third lens is greater than the radius of curvature of the surface facing the first lens, and both are negative; the radius of curvature of the surface of the third lens facing the laser receiving plate is smaller than the radius of curvature of the surface facing the second lens, and both are negative.

[0018] This application provides a lidar, which includes a transmitting device and at least two receiving devices. The transmitting device includes a laser emitting plate, a microlens assembly, and a microprism assembly. The laser emitting plate emits laser light towards the object to be measured. The microlens assembly is used to collide the laser light with the microprism assembly, and the microprism assembly is used to diverge the collimated laser light. At least two receiving devices are respectively disposed on both sides of the transmitting device. Each receiving device includes a laser receiving plate, a lens group, and a wide-angle lens group. The laser light reflected back from the object to be measured passes sequentially through the wide-angle lens group and the lens group and converges onto the laser receiving plate. By distributing at least two receiving devices on both sides of the transmitting device, both receiving devices can receive the laser light reflected back from the object to be measured, thereby giving the lidar an extremely large elevation field of view, thus increasing the elevation field of view and measurement range. Furthermore, this lidar also has advantages such as simple structure and low manufacturing cost. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a cross-sectional structure of a lidar provided in an embodiment of this application;

[0021] Figure 2 for Figure 1 The diagram shown is a structural schematic of the transmitting device in a lidar system.

[0022] Figure 3 for Figure 1 The diagram shown is a structural schematic of the receiving device in a lidar system.

[0023] Figure 4 for Figure 1The diagram shows the field of view range of the lidar.

[0024] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] 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.

[0027] Please refer to Figures 1 to 3 , Figure 1 A schematic diagram of a cross-sectional structure of a lidar provided in an embodiment of this application; Figure 2 for Figure 1 The diagram shown is a structural schematic of the transmitting device in a lidar system. Figure 3 for Figure 1 The diagram shows the structure of the receiving device in a lidar system. Figures 1 to 3 Only a portion of the structure is shown. It is understood that the actual lidar 100, transmitter 10, and receiver 20 also include other components or structures not shown in the figures.

[0028] like Figure 1 and Figure 2 As shown, the lidar 100 includes a transmitting device 10, which includes a microlens assembly 11, a microprism assembly 12, and a laser emitting plate 13. The laser emitting plate 13 is used to emit laser light towards the object to be measured.

[0029] In one embodiment, the laser emitting plate 13 includes at least one light-emitting unit for emitting laser light. It should be noted that... Figure 2 The laser emitting plate 13 shown only schematically illustrates 11 light-emitting units. In practical applications, the number and arrangement of these light-emitting units can be set according to actual needs.

[0030] In one embodiment, the light-emitting unit can be a vertical-cavity surface-emitting laser (VCSEL), or other lasers, such as an edge-emitting laser (EEL). The specific type of the light-emitting unit can be set according to actual needs, and no specific limitation is made here.

[0031] like Figure 2 As shown, the microlens assembly 11 is used to collimate the laser to the microprism assembly 12. The laser emitted by the light-emitting unit is incident on the microlens assembly 11, the microlens assembly 11 collimates the laser, and the collimated laser is incident on the microprism assembly 12.

[0032] In one embodiment, such as Figure 2 As shown, the microlens assembly 11 includes a first light-transmitting substrate 111 and at least one microlens array 112, wherein the microlenses in the microlens array 112 correspond to the light-emitting unit, the light-emitting unit is located at the focal point of the microlens, and the microlens array 112 is used to collimate the laser emitted by the light-emitting unit.

[0033] In one embodiment, when the light-emitting unit is a vertical cavity surface-emitting laser, the microlens array 112 can be a microspherical lens array or a microaspherical lens array.

[0034] In one embodiment, when the light-emitting unit is a side-emitting laser, the microlens assembly 11 includes two first transparent substrates 111 and two microlens arrays 112, wherein the two microlens arrays 112 are a fast-axis collimating microcylindrical lens array and a slow-axis collimating microcylindrical lens array, respectively, and the two microlens arrays 112 are respectively formed on the surfaces of the two first transparent substrates 111 that are away from the light-emitting unit. In this way, after the laser is emitted from the light-emitting unit, it passes sequentially through the first transparent substrate 111, the fast-axis collimating microcylindrical lens array, the other first transparent substrate 111, and the slow-axis collimating microcylindrical lens array.

[0035] like Figure 2 As shown, the microprism assembly 12 is used to diverge the aligned laser, thereby forming measurement lasers in different directions, which are directed at the object to be measured.

[0036] In one embodiment, the microprism assembly 12 includes a light-transmitting substrate 121 and a microprism array 122 formed on a surface of the light-transmitting substrate 121 remote from the microlens assembly 11. The microprism array 122 includes reflective microprisms 1221 and refractive microprisms 1222. The reflective microprisms 1221 are disposed near the edge of the light-transmitting substrate 121, and the refractive microprisms 1222 are disposed near the center of the light-transmitting substrate 121. The microprisms in the microprism array 122 correspond to the microlenses in the microlens array 112. That is, as... Figure 2 As shown, from the edge to the center of the light-transmitting substrate 121 (i.e. Figure 2 (As indicated by arrows A and B), the reflecting microprism 1221 is closer to the edge of the light-transmitting substrate 121 than the refractive microprism 1222, and the refractive microprism 1222 is closer to the center of the light-transmitting substrate 121 than the reflecting microprism 1221.

[0037] In one embodiment, the inclined surface of the reflective microprism 1221 is coated with an internal reflective film. Of course, in other embodiments, the inclined surface of the reflective microprism 1221 may not be coated with an internal reflective film, or may be partially coated with an internal reflective film; no specific limitations are imposed here.

[0038] In one embodiment, such as Figure 2 As shown, in the direction from the edge of the light-transmitting substrate 121 to the center of the light-transmitting substrate 121 (i.e. Figure 2 (As indicated by arrows A and B) the tilt angle α of the reflective microprism 1221 increases sequentially, and the tilt angle α of the reflective microprism 1221 is greater than or equal to the critical refraction angle of the reflective microprism 1221. The tilt angle α of the reflective microprism 1221 is the angle between the inclined surface of the reflective microprism 1221 and the surface of the light-transmitting substrate 121.

[0039] In one embodiment, the inclined surface of the refractive microprism 1222 is coated with an antireflective film. Of course, in other embodiments, the inclined surface of the refractive microprism 1222 may not be coated with an antireflective film, as long as its refractive function can be achieved and refracted light at the corresponding angle can be obtained.

[0040] In one embodiment, such as Figure 2 As shown, in the direction from the edge of the light-transmitting substrate 121 to the center of the light-transmitting substrate 121, the tilt angle θ of the refractive microprism 1222 decreases sequentially, wherein the tilt angle θ of the refractive microprism 1222 is the angle between the inclined surface of the refractive microprism 1222 and the surface of the light-transmitting substrate 121.

[0041] In one embodiment, such as Figure 2As shown, in the microlens assembly 11, there is at least one microlens that does not correspond to the microprisms in the microprism array 122 but corresponds to the direct-lighting region C of the light-transmitting substrate 121, so that the collimated laser directly passes through the direct-lighting region C and is emitted directly, thereby forming a laser with a 90° pitch field of view in the emitted light path.

[0042] In one embodiment, the direct-light region C is located near the center of the light-transmitting substrate 121, so that both the reflective microprism 1221 and the refractive microprism 1222 can be symmetrically arranged about the direct-light region C. For example, as Figure 2 As shown, the reflecting microprisms 1221 located on the left and right sides of the direct-light region C are symmetrically arranged about the direct-light region C. Similarly, the refractive microprisms 1222 located on the left and right sides of the direct-light region C are symmetrically arranged about the direct-light region C. In this way, the reflecting microprism 1221 and the refractive microprism 1222 located on the right side of the direct-light region C perform internal reflection and refraction of the laser beam after direct illumination, respectively, and the elevation field of view of the emitted laser can be achieved from 0° to 90°. Meanwhile, the reflecting microprism 1221 and the refractive microprism 1222 located on the left side of the direct-light region C perform internal reflection and refraction of the laser beam after direct illumination, and the elevation field of view of the emitted laser can be achieved from 90° to 180°. At the same time, since the direct-light region C does not refract the laser beam after direct illumination, the elevation field of view of the laser emitted from the direct-light region C can be 90°. Therefore... Figure 2 The transmitting device 10 shown can achieve a pitch field of view range of 0° to 180°, so that the lidar 100 has a panoramic pitch field of view range in the transmission optical path, which increases the measurement range and applicability of the lidar 100.

[0043] Additionally, it should be noted that the aforementioned light-transmitting substrate 121 can also be referred to as the second light-transmitting substrate.

[0044] like Figure 1 and Figure 3 As shown, the lidar also includes two receiving devices 20, which are respectively disposed on both sides of the transmitting device 10, for receiving the laser reflected back by the object to be measured.

[0045] In one embodiment, such as Figure 1 As shown, the two receiving devices 20 are symmetrically arranged about the transmitting device 10. Of course, in other embodiments, the two receiving devices 20 may not be symmetrically arranged about the transmitting device 10, as long as both receiving devices 20 can receive the light reflected back from the object under test. Alternatively, the positions of the two receiving devices 20 can be designed according to requirements to achieve the desired elevation field of view. Furthermore, the number of receiving devices 20 is not limited. Figure 1The two shown can be more than one, that is, the lidar 100 includes at least two receiving devices 20. The specific number of receiving devices 20 can be designed according to the requirements and is not specifically limited here.

[0046] like Figure 1 and Figure 3 As shown, the receiving device 20 includes an expanding lens group 21, a lens group 22, and a laser receiving plate 23. The laser reflected back by the object under test passes through the expanding lens group 21 and the lens group 22 in sequence and is converged onto the laser receiving plate 23. Thus, by setting at least two receiving devices 20, all the laser reflected back by the object under test can be received, thereby achieving a large pitch field of view in the receiving optical path, thereby improving the overall pitch field of view of the lidar 100 and increasing the measurement range of the lidar 100.

[0047] In one embodiment, such as Figure 3 As shown, the expanding lens group 21 includes a first expanding lens 211 and a second expanding lens 212. The laser reflected back by the object under test passes through the first expanding lens 211 and the second expanding lens 212 in sequence before being directed towards the lens group 22. The radius of curvature of the surface of the first expanding lens 211 facing the second expanding lens 212 is smaller than the radius of curvature of the surface facing the object under test, and both are positive values. The radius of curvature of the surface of the second expanding lens 212 facing the lens group 22 is smaller than the radius of curvature of the surface facing the first expanding lens 211, and both are positive values.

[0048] In one embodiment, such as Figure 3 As shown, the lens group 22 includes a first lens 221, a second lens 222, and a third lens 223. The laser beam converged by the expanding lens group 21 passes sequentially through the first lens 221, the second lens 222, and the third lens 223 before being incident on the laser receiving plate 23. The radius of curvature of the surface of the first lens 221 facing the second lens 222 is negative, and the radius of curvature of the surface of the first lens 221 facing the expanding lens group 21 is positive. The radius of curvature of the surface of the second lens 222 facing the third lens 223 is greater than the radius of curvature of the surface facing the first lens 221, and both are negative. The radius of curvature of the surface of the third lens 223 facing the laser receiving plate 23 is smaller than the radius of curvature of the surface facing the second lens 222, and both are negative.

[0049] By rationally designing the parameters and positions of each lens, the elevation field of view of each receiving device 20 can reach 120°. Since at least two receiving devices 20 are positioned on either side of the transmitting device 10 and will not be obstructed, the elevation field of view of the receiving device 20 will not be lost. When the transmission elevation field of view of the transmitting device 10 is within the range of 0° to 180°, Figure 1The receiving device 20 shown above can receive reflected laser beams with angles ranging from below zero degrees to above 90 degrees. Figure 1 The receiving device 20 shown below can receive reflected laser angles ranging from less than 90° to greater than 180°, thus giving the lidar 100 an ultra-large pitch field of view in both transmission and reception, resulting in a panoramic pitch field of view. When the motor in the lidar 100 drives the transmitting device 10 and the receiving device 20 to rotate, a 360°*360° panoramic field of view can be achieved, such as... Figure 4 As shown.

[0050] The lidar 100 provided in this application embodiment has at least two receiving devices 20 arranged on both sides of the transmitting device 10, so that at least two receiving devices 20 can receive the laser reflected back by the object to be measured, thereby giving the lidar 100 an ultra-large receiving pitch field of view range, thereby increasing the pitch field of view range of the lidar 100 and increasing the measurement range of the lidar 100. At the same time, the lidar 100 also has the advantages of simple structure and low manufacturing cost.

[0051] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, the components and arrangements of specific examples are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application are within the scope of protection claimed by this application.

[0052] Furthermore, reference numerals and / or reference letters may be repeated in different examples in this application. Such repetition is for simplification and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, this application provides examples of various specific processes and materials; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

Claims

1. A lidar, characterized in that, include: The emitting device includes a laser emitting plate, a microlens assembly, and a microprism assembly. The laser emitting plate emits laser light toward the object to be tested. The microlens assembly is used to collide the laser light with the microprism assembly. The microprism assembly is used to diverge the collimated laser light. as well as At least two receiving devices are respectively disposed on both sides of the transmitting device. Each receiving device includes a laser receiving plate, a lens group, and a wide-angle lens group. The laser reflected back by the object under test is converged onto the laser receiving plate by the wide-angle lens group and the lens group in sequence.

2. The lidar according to claim 1, characterized in that, At least two of the receiving devices are symmetrically arranged about the transmitting device.

3. The lidar according to claim 1, characterized in that, The laser emitting plate includes at least one light-emitting unit, which is used to emit the laser; The microlens assembly includes at least one microlens array, wherein the microlenses in the microlens array correspond to the light-emitting unit, the light-emitting unit is located at the focal point of the microlens, and the microlens array is used to collimate the laser emitted by the light-emitting unit; The microprism assembly includes a light-transmitting substrate and a microprism array formed on a surface of the light-transmitting substrate away from the microlens assembly. The microprism array includes reflective microprisms and refractive microprisms. The reflective microprisms are disposed near the edge of the light-transmitting substrate, and the refractive microprisms are disposed near the center of the light-transmitting substrate. The microprisms in the microprism array correspond to the microlenses in the microlens array.

4. The lidar according to claim 3, characterized in that, In the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, the tilt angle of the reflective microprism increases sequentially, and the tilt angle of the reflective microprism is greater than or equal to the critical refraction angle of the reflective microprism, wherein the tilt angle of the reflective microprism is the angle between the inclined surface of the reflective microprism and the surface of the light-transmitting substrate.

5. The lidar according to claim 3, characterized in that, In the direction from the edge of the light-transmitting substrate to the center of the light-transmitting substrate, the tilt angle of the refractive microprism decreases sequentially, wherein the tilt angle of the refractive microprism is the angle between the inclined surface of the refractive microprism and the surface of the light-transmitting substrate.

6. The lidar according to claim 3, characterized in that, In the microlens assembly, at least one microlens does not correspond to a microprism in the microprism array but corresponds to the direct-light region of the light-transmitting substrate, so that the collimated laser directly passes through the direct-light region and is emitted directly.

7. The lidar according to claim 6, characterized in that, The direct-light region is located near the center of the light-transmitting substrate, and the reflective microprism and the refractive microprism are symmetrically arranged about the direct-light region.

8. The lidar according to claim 3, characterized in that, The inclined surface of the reflective microprism is coated with an internal reflective film, and the inclined surface of the refractive microprism is coated with an anti-reflective film.

9. The lidar according to claim 1, characterized in that, The expanding lens group includes a first expanding lens and a second expanding lens. The laser reflected back by the object under test passes sequentially through the first expanding lens and the second expanding lens before being directed towards the lens group. The radius of curvature of the surface of the first expanding lens facing the second expanding lens is smaller than the radius of curvature of the surface facing the object under test, and both are positive values. The radius of curvature of the surface of the second expanding lens facing the lens group is smaller than the radius of curvature of the surface facing the first expanding lens, and both are positive values.

10. The lidar according to claim 1, characterized in that, The lens group includes a first lens, a second lens, and a third lens. Laser light converged by the expanding lens group passes sequentially through the first lens, the second lens, and the third lens before entering the laser receiving plate. Specifically, the radius of curvature of the surface of the first lens facing the second lens is negative, and the radius of curvature of the surface of the first lens facing the expanding lens group is positive. The radius of curvature of the surface of the second lens facing the third lens is greater than the radius of curvature of the surface facing the first lens, and both are negative. The radius of curvature of the surface of the third lens facing the laser receiving plate is smaller than the radius of curvature of the surface facing the second lens, and both are negative.

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