Laser radar

Abstract

A laser radar, comprising a transmitter (110), a receiver (120), a beam splitter (130) and an optical device. The transmitter (110) is configured to generate detection light. The receiver (120) is configured to receive echo light formed by the detection light which is reflected by an object. The beam splitter (130) is configured to separate a light path of the echo light from a light path of the detection light. The optical device comprises: a common lens group (141), the common lens group (141) being configured to transmit the detection light and the echo light and converge the echo light to the receiver (120); and a transmitting lens group (142), the transmitting lens group (142) and the common lens group (141) being configured to collimate the detection light. The laser radar is provided with the common lens group (141), such that the number of non-common optical devices at a transmitting end and a receiving end in the laser radar can be reduced, which facilitates simplifying the structure of the laser radar and reducing the impact of the tolerance of the optical device in the laser radar on the performance of the laser radar.

Description

LiDAR

[0001] This disclosure claims priority to a Chinese patent application titled “Laser Radar” with application number 202410111184.2 filed on January 25, 2024, and priority to a Chinese patent application titled “Laser Radar” with application number 202420189597.8 filed on January 25, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

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

[0003] LiDAR is a range-finding sensor with long detection range, high resolution, and minimal environmental interference. It is widely used in autonomous driving, intelligent robots, drones, and other fields. Autonomous driving technology is developing rapidly, with LiDAR serving as a core sensor.

[0004] In a LiDAR scanner, the reflective surface of the scanner reflects the light beam, forming a scanning beam for three-dimensional space scanning. The LiDAR scanner uses the reciprocating motion of the reflective surface to scan the scanning beam within the LiDAR's field of view.

[0005] However, existing lidars find it difficult to balance detection performance, simplify structure, and reduce installation difficulty. Summary of the Invention

[0006] The problem solved by the present disclosure is to simplify the structure of the laser radar and reduce the difficulty of installation and adjustment while ensuring the detection performance of the laser radar.

[0007] To solve the above problems, the present disclosure provides a laser radar, comprising:

[0008] A transmitter and a receiver, wherein the transmitter is configured to generate a detection light, and the receiver is configured to receive the echo light formed by the reflection of the detection light by an object; a spectrometer, wherein the spectrometer is configured to separate the optical path of the echo light from the optical path of the detection light; an optical device, wherein the optical device comprises: a common lens group, wherein the common lens group is configured to transmit the detection light and the echo light; the common lens group is further configured to converge the echo light to the receiver; and an emission lens group, wherein the emission lens group is located in the optical path between the transmitter and the spectrometer, and the emission lens group and the common lens group are configured to collimate the detection light.

[0009] Optionally, the optical center of the beam splitter is located within an aperture stop formed by the detection light passing through the emitting lens group.

[0010] Optionally, the focus of the emission lens group is located at the center of the aperture stop.

[0011] Optionally, the emission lens group is configured to compress the divergence angle of the detection light generated by the emitter.

[0012] Optionally, the detection light sequentially transmits the emission lens group and the common lens group to form a telecentric optical path.

[0013] Optionally, the angle between the principal ray of the detection light and the optical axis of the emitting lens group is less than 5°.

[0014] Optionally, all lenses of the emitting lens group are positive lenses.

[0015] Optionally, the optical device further includes: a receiving lens group, wherein the receiving lens group is located in the optical path between the receiver and the spectrometer, and the receiving lens group and the shared lens group cooperate to converge the echo light to the receiver.

[0016] Optionally, all lenses of the receiving lens group are positive lenses.

[0017] Optionally, the laser radar further includes: a receiving reflector, wherein the receiving reflector is located between the receiving lens group and the receiver to change the optical path of the echo light.

[0018] Optionally, the laser radar further includes: a transmitting reflector, wherein the transmitting reflector is located between the transmitting lens group and the transmitter to change the optical path of the detection light.

[0019] Optionally, the receiver includes: a detector, which is a two-dimensional array detector, and the two-dimensional array detector includes: a plurality of detection areas, and the plurality of detection areas correspond one-to-one to the plurality of lasers of the transmitter.

[0020] Optionally, the receiver includes: a plurality of detectors, and the plurality of detectors correspond one-to-one to the plurality of lasers of the transmitter.

[0021] Optionally, the plurality of detectors are arranged in an array; detectors in adjacent columns are staggered along the column direction, or detectors in adjacent rows are staggered along the row direction.

[0022] Optionally, the receiver includes a plurality of detector groups, one of the plurality of detector groups includes a plurality of detectors, and the plurality of detector groups correspond one-to-one to the plurality of lasers of the transmitter.

[0023] Optionally, the groups are arranged along the row direction, the multiple detectors in the same detector group among the multiple detector groups are arranged along the column direction, and the detectors of adjacent detector groups are staggered along the column direction; or, the multiple detector groups are arranged along the column direction, the multiple detectors in a detector group among the multiple detector groups are arranged along the row direction, and the detectors of adjacent detector groups are staggered along the row direction.

[0024] Optionally, the laser radar further includes: a light homogenizer, which is located in the optical path of the detection light.

[0025] Optionally, the laser in the transmitter and the detector in the receiver are arranged on the same circuit board.

[0026] Optionally, the beam splitter includes an aperture reflector or a partial reflector.

[0027] Optionally, the optical center of the beam splitter is the center of the aperture of the aperture reflector; or, the optical center of the beam splitter is the center of the transmission area in the partial reflector.

[0028] Optionally, it also includes: a scanner, which is configured to emit the detection light to the outside of the laser radar and receive the echo light emitted to the spectrometer; the spectrometer transmits the detection light generated by the transmitter to the scanner, and the spectrometer also transmits the echo light received by the scanner to the receiver.

[0029] Optionally, the scanner includes: at least one reflecting surface that moves around a rotation axis, and an angle between the reflecting surface and the rotation axis has a preset value.

[0030] Optionally, the scanner includes: a plurality of the reflecting surfaces, and the angles between the plurality of reflecting surfaces and the rotating shaft are the same.

[0031] Optionally, the field of view of the laser radar includes: an edge area and a central area, the central area is located between the two edge areas; the detection light reflected by adjacent reflecting surfaces covers the central area; the detection light reflected by adjacent reflecting surfaces covers different edge areas.

[0032] Optionally, the scanner has an even number of reflective surfaces, wherein adjacent reflective surfaces have different angles with the rotation axis, and spaced reflective surfaces have the same angle with the rotation axis.

[0033] The technical solution disclosed in this disclosure has the following advantages:

[0034] In some embodiments of the present disclosure, the optical device includes a shared lens group and a transmitting lens group, wherein the shared lens group is configured to converge the return light to the receiver, and the transmitting lens group and the shared lens group are configured to collimate the detection light. Providing the shared lens group can reduce the number of non-shared optical devices at the transmitting and receiving ends of the laser radar, simplifying the structure of the laser radar and reducing the impact of the tolerance of the optical devices on the laser radar performance.

[0035] In other embodiments of the present disclosure, the optical center of the beam splitter is located within the aperture formed by the probe light passing through the transmitting lens group; the transmitting lens group is configured to compress the divergence angle of the probe light generated by the transmitter. The arrangement of the beam splitter and the transmitting lens group is conducive to improving the transmission efficiency of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work. The drawings are used to provide a further understanding of the present disclosure and constitute part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the drawings:

[0037] FIG1 shows a functional block diagram of an embodiment of a laser radar of the present disclosure;

[0038] FIG2 shows a schematic diagram of an optical path structure of a laser radar consistent with some embodiments of the present disclosure;

[0039] FIG3 shows a schematic structural diagram of an aperture reflector of a beam splitter in a laser radar consistent with some embodiments of the present disclosure;

[0040] FIG4 shows a schematic diagram of the structure of a partial reflector of a beam splitter in a laser radar consistent with some embodiments of the present disclosure;

[0041] FIG5 shows a functional block diagram of another embodiment of the laser radar of the present disclosure;

[0042] FIG6 shows another optical path structure schematic diagram of a laser radar consistent with some embodiments of the present disclosure;

[0043] FIG7 shows a corresponding schematic diagram of a laser and a detector in a laser radar consistent with some embodiments of the present disclosure;

[0044] FIG8 shows a functional block diagram of another embodiment of the laser radar of the present disclosure;

[0045] FIG9 shows another optical path structure schematic diagram of a laser radar consistent with some embodiments of the present disclosure;

[0046] FIG10 shows a schematic diagram of the field of view of a laser radar consistent with some embodiments of the present disclosure;

[0047] FIG11 shows a corresponding schematic diagram of another laser and detector in a laser radar consistent with some embodiments of the present disclosure;

[0048] FIG12 shows a corresponding schematic diagram of yet another laser and detector in a lidar consistent with some embodiments of the present disclosure. DETAILED DESCRIPTION

[0049] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0050] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present disclosure. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present disclosure, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0051] In the description of this disclosure, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0052] In the present disclosure, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0053] The disclosure below provides many different embodiments or examples for realizing different structures of the present disclosure. In order to simplify the content of the present disclosure, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present disclosure. In addition, the present disclosure may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0054] As can be seen from the background technology, it is difficult for the laser radar in the existing technology to simplify the laser radar structure and reduce the difficulty of installation and adjustment while ensuring the detection performance.

[0055] To solve the technical problem, the present disclosure provides a laser radar, comprising: a transmitter and a receiver, wherein the transmitter is configured to generate detection light, and the receiver is configured to receive echo light formed by reflection of the detection light by an object; a spectrometer, wherein the spectrometer is configured to separate the optical path of the echo light from the optical path of the detection light; an optical device, wherein the optical device comprises: a common lens group, wherein the common lens group is configured to transmit the detection light and the echo light, and the common lens group is further configured to converge the echo light to the receiver; and an emitting lens group, wherein the emitting lens group is located in the optical path between the transmitter and the spectrometer, and the emitting lens group and the common lens group are configured to collimate the detection light.

[0056] The laser radar disclosed in the present invention is provided with the shared lens group, which can reduce the number of non-shared optical devices at the transmitting and receiving ends of the laser radar, is conducive to simplifying the structure of the laser radar, and can reduce the impact of the tolerance of the optical devices in the laser radar on the performance of the laser radar.

[0057] In order to make the above-mentioned objects, features and advantages of the present disclosure more obvious and easy to understand, specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0058] 1 , there is shown a functional block diagram of an embodiment of a laser radar of the present disclosure.

[0059] With reference to FIG2 , FIG2 shows a schematic diagram of the optical path structure of a laser radar consistent with some embodiments of the present disclosure.

[0060] The laser radar includes: a transmitter 110 and a receiver 120, the transmitter 110 can generate detection light, and the receiver 120 can receive echo light formed by the reflection of the detection light by an object; a spectrometer 130, the spectrometer 130 can separate the optical path of the echo light from the optical path of the detection light; an optical device, the optical device includes: a shared lens group 141, the shared lens group 141 can transmit the detection light and the echo light; the shared lens group 141 can also converge the echo light to the receiver 120; an emitting lens group 142, the emitting lens group 142 is located in the optical path between the transmitter 110 and the spectrometer 130, and the emitting lens group 142 and the shared lens group 141 can collimate the detection light.

[0061] The specific technical solution of the laser radar embodiment is described in detail below with reference to the accompanying drawings.

[0062] The emitter 110 may generate detection light.

[0063] In some embodiments, the transmitter 110 may include multiple lasers, each of which may generate a beam of probe light, and the emission areas formed by the probe light in the field of view of the laser radar do not overlap. For example, the multiple lasers may be arranged along a preset first direction so that the generated probe light covers the vertical field of view of the laser radar, and the total emission area formed by the probe light generated by the multiple lasers in the field of view of the laser radar may match the vertical field of view of the laser radar, where the first direction corresponds to the direction of the vertical field of view of the laser radar.

[0064] In some embodiments, the laser may be a vertical-cavity surface-emitting laser (VCSEL). In other embodiments of the present disclosure, the laser may also be an edge-emitting laser (EEL) or other light emitter capable of generating laser light. The wavelength of the laser light emitted by the laser may be any one of 905 nm, 940 nm, or 1550 nm, and the laser may also emit laser light of other wavelengths.

[0065] The receiver 120 can detect the echo light generated by the light reflected by the object.

[0066] In some embodiments of the present disclosure, the receiver 120 may include: 1 detector, which may be a two-dimensional array detector, which may include: multiple detection areas, and the multiple detection areas correspond one-to-one to the multiple lasers of the transmitter 110.

[0067] For example, a two-dimensional array detector may include multiple detection regions arranged in two dimensions, which may be activated by two-dimensional addressing to receive echo light. The detection regions may include single-photon detectors, which may be single-photon avalanche diodes (SPADs) or silicon photomultipliers (SiPMs).

[0068] Each detection area in the plurality of detection areas may include a plurality of pixels. A pixel may include a plurality of SPADs. For example, each pixel in the plurality of pixels may include 2×2 or 3×3 SPADs, and each pixel in the plurality of pixels (for example, 4 or 9 SPADs) may be individually strobed to output a signal for subsequent circuit collection and processing. In other embodiments of the present disclosure, each detection area in the plurality of detection areas may include a plurality of detection units, such as SPADs. Each detection unit in the plurality of detection units may be individually strobed to output a signal for subsequent circuit collection and processing.

[0069] Multiple detection areas in a two-dimensional array detector can be detected using a time-sharing activation method, each pixel in the detection area can be selected and controlled using an independent addressing method, and multiple SPADs (for example, 2×2 or 3×3 SPADs) can be activated simultaneously as a pixel. The lidar can produce a higher point cloud density.

[0070] In some embodiments, the two-dimensional array detector may further include a compensation region surrounding the plurality of detection regions.

[0071] The compensation area may include multiple pixels. The pixel may include multiple SPADs. For example, each of the multiple pixels may include 2×2 or 3×3 SPADs, and each of the multiple pixels (4 or 9 SPADs) may be individually strobed to output 1 signal for subsequent circuit collection and processing. In other embodiments of the present disclosure, the compensation area may include multiple detection units, such as SPADs. Each of the multiple detection units may be individually strobed to output 1 signal for subsequent circuit collection and processing.

[0072] Multiple compensation areas in a two-dimensional array detector can be detected using a time-sharing activation method, each pixel in the compensation area can be selected and controlled using an independent addressing method, and multiple SPADs (for example, 2×2 or 3×3 SPADs) can be activated simultaneously as a pixel, and the lidar can produce a higher point cloud density. The two-dimensional array detector can achieve alignment of the transmitting field of view and the receiving field of view by addressing and selecting the pixels in the detection area and the compensation area. The pixels in the activated compensation area and the pixels in the activated detection area can be combined to form a compensation detection area. The compensation detection area corresponds one-to-one to the laser. The compensation area can compensate for the deviation between the transmitting field of view and the receiving field of view, which can simplify or omit the optical device adjustment process and reduce the difficulty of adjustment.

[0073] It should also be noted that, in some embodiments shown in FIG. 1 and FIG. 2 , a filter 121 is further provided in the return light path upstream of the receiver 120 to suppress stray light and improve the signal-to-noise ratio.

[0074] The optical splitter 130 can separate the optical path of the echo light and the optical path of the probe light.

[0075] In some embodiments, the beam splitter 130 may include an apertured reflector or a partial reflector. Using an apertured reflector or a partial reflector for beam splitting can reduce the requirements of the laser radar for the transmitter 110. For example, the transmitter can emit unpolarized light or circularly polarized light, and the laser radar does not use a polarization beam splitter, which helps reduce costs.

[0076] Figure 3 illustrates a schematic diagram of an aperture reflector for a beam splitter in a laser radar system consistent with some embodiments of the present disclosure. As shown in Figure 3 , beam splitter 130 includes an aperture reflector. The aperture reflector includes a reflective surface 132 and an aperture 131 within the reflective surface 132. In some embodiments, the reflective surface 132 and aperture 131 are both circular and concentrically arranged.

[0077] In some embodiments, the beam splitter 130 has an optical center 133 . As shown in FIG. 3 , the optical center 133 of the aperture reflector in the beam splitter 130 is the geometric center of the aperture 131 .

[0078] In some other embodiments, the beam splitter includes a partial reflector, which includes a reflective region and a transmissive region. The transmissive region can transmit the probe light, and the reflective region can transmit the echo light, and the reflective region surrounds the transmissive region.

[0079] Figure 4 illustrates a schematic diagram of a partial reflector for a beam splitter in a laser radar consistent with some embodiments of the present disclosure. In some embodiments, as shown in Figure 4 , the partial reflector includes a reflective region 231 and a transmissive region 232 , with the reflective region 231 surrounding the transmissive region 232 . The transmissive region 232 can transmit the probe light, while the reflective region 232 can reflect the return light.

[0080] For example, the optical center 233 of the beam splitter is the geometric center of the area in the partial reflector that transmits the probe light. As shown in Figure 4, the optical center 233 of the beam splitter is the center of the transmission area in the partial reflector.

[0081] Continuing with reference to Figure 1, in some embodiments, the laser radar also includes: a scanner 160, which can emit detection light to the outside of the laser radar and receive echo light and emit it to the spectrometer 130; the spectrometer 130 transmits the detection light generated by the transmitter 110 to the scanner 160, and the spectrometer 130 also transmits the echo light received from the scanner 160 to the receiver 120.

[0082] The multiple lasers of the transmitter 110 are arranged along the first direction. In some embodiments shown in FIG1 , the scanner 160 is a one-dimensional scanner that scans the probe light along a second direction that intersects the first direction, for example, the second direction is perpendicular to the first direction.

[0083] The scanner 160 may include at least one of a MEMS, a polygonal mirror, a galvanometer mirror, or a oscillating mirror. The scanner 160 may reflect the detection light so that the detection light is emitted in different directions outside the laser radar to form a horizontal field of view of the laser radar. As shown in FIG2 , the scanner 160 includes: at least one reflecting surface that moves around the rotation axis 163, for example, the reflecting surface can rotate 360°, and the angle between the reflecting surface and the rotation axis 163 has a preset value. In some embodiments, the preset value may be 0°. In some embodiments, the preset value may be any non-zero angle, for example, 0.1°, 0.2°, 1°, 5°, -0.1°, -0.2°, -1°, -5°, etc. Among them, the positive and negative values ​​indicate that the directions of the angles between the reflecting surface and the rotation axis are different.

[0084] In some embodiments as shown in Figure 2, the scanner 160 includes a multi-faceted rotating mirror 161, which includes multiple reflecting surfaces, such as reflecting surface 1621, reflecting surface 1622, reflecting surface 1623, reflecting surface 1624 and reflecting surface 1625, and the multiple reflecting surfaces all rotate 360° around the rotation axis 163.

[0085] The angles between the multiple reflective surfaces and the rotation axis 163 are not all the same. At least one reflective surface has a different angle with the rotation axis 163 than the angles between the other reflective surfaces 162 and the rotation axis 163. The angles between reflective surfaces 1621, 1622, 1623, 1624, and 1625 and the rotation axis 163 are not all the same. For example, reflective surfaces 1621, 1623, and 1625 have the same angle α with the rotation axis 163; reflective surfaces 1622 and 1624 have the same angle β with the rotation axis 163. However, reflective surfaces 1621 and 1622 have different angles with the rotation axis 163, namely, angle α and angle β are different. Continuing with Figures 1 and 2, the lidar also includes an optical system for transmitting detection light and return light. The optical system includes a common lens group 141 and a transmitting lens group 142.

[0086] The transmitting lens group 142 is located in the optical path between the beam splitter 130 and the transmitter 110. The transmitting lens group 142 and the common lens group 141 sequentially transmit the detection light from the transmitter 110, and the detection light is emitted from the laser radar.

[0087] As shown in Figures 1 and 2, the laser radar also includes a scanner 160, and a shared lens group 141 is located in the optical path between the beam splitter 130 and the scanner 160. The probe light generated by the transmitter 110 is sequentially transmitted through the transmitting lens group 142 and the beam splitter 130, and then transmitted to the shared lens group 141. The probe light transmitted by the beam splitter 130 is transmitted through the shared lens group 141 and reflected by the scanner 160 to the outside of the laser radar, and then emitted from the laser radar.

[0088] The transmitting optical system in the laser radar includes a shared lens group 141 and a transmitting lens group 142. The transmitting optical system adjusts the optical path of the detection light and shapes and collimates the detection light. Transmitting lens group 142 includes at least one lens, and shared lens group 141 includes at least one lens. The optical parameters of the lenses of transmitting lens group 142 and shared lens group 141 can be determined based on the transmission requirements of the detection light. In some embodiments, transmitting lens group 142 can include one to three lenses, and shared lens group 141 can include one to three lenses.

[0089] In some embodiments of the present disclosure, the emitting lens group 142 can compress the divergence angle of the detection light generated by the emitter 110 so that the detection light is transmitted to the optical center or near the optical center of the spectrometer 130. For example, the opening 131 of the aperture reflector shown in Figure 3 is the optical center of the spectrometer, and the transmission area 232 of the local reflector shown in Figure 4 is the optical center of the spectrometer, so that as much detection light as possible is emitted from the spectrometer 130, which is beneficial to improving the emission efficiency of the lidar.

[0090] In some embodiments, the optical center of the beam splitter 130 is located within the aperture stop formed by the probe light passing through the emission lens group 142.

[0091] In some embodiments of the present disclosure, the emitter 110 may be located on the focal plane of the emission lens group 142 .

[0092] In some embodiments of the present disclosure, the transmitting optical system may include a telecentric lens. The detection light may sequentially transmit through the transmitting lens group 142 and the shared lens group 141 to form a telecentric optical path. In some embodiments, the angle between the chief ray of the detection light and the optical axis of the transmitting lens group 142 may be less than 5° to improve the telecentricity of the telecentric optical path and the detection performance of the lidar.

[0093] In some embodiments, as shown in FIG2 , all lenses in transmitting lens group 142 are positive lenses, thereby compressing the divergence angle of the detection light and ensuring the telecentricity of the detection light's optical path. Transmitting lens group 142 is a positive lens group, with one to three lenses in transmitting lens group 142 being positive lenses. Transmitting lens group 142 has a short focal length, which effectively compresses the laser radar's optical path length along the detection light's propagation direction, facilitating the miniaturization of the laser radar.

[0094] The emitted detection light is reflected outside the laser radar to form an echo light, and the scanner 160 of the laser radar receives the echo light and reflects the received echo light toward the common lens group 141. The common lens group 141 converges the echo light to the receiver 120.

[0095] The shared lens group 141 can constitute the receiving lens of the laser radar optical system. In some embodiments, the shared lens group 141 has at least one lens. The selection and design of the lens of the shared lens group 141 can be determined based on the reception requirements of the echo light.

[0096] Since the lenses of the common lens group 141 are used for both converging the echo light and collimating the detection light, the selection and design of the lenses of the common lens group 141 take into account both the emission requirements of the detection light and the reception requirements of the echo light.

[0097] In some embodiments as shown in Figures 1 and 2, the optical device also includes: a receiving lens group 143, which is located in the optical path between the receiver 120 and the spectrometer 130. The receiving lens group 143 and the shared lens group 141 cooperate to converge the echo light to the receiver 120.

[0098] In some embodiments shown in Figures 1 and 2, the receiving lens group 143 and the shared lens group 141 can cooperate with each other to form a receiving lens group of the lidar optical system to adjust the optical path of the echo light so that the echo light converges to the receiver 120.

[0099] The receiving lens group 142 may have at least one lens, and the selection and design of the lens of the transmitting lens group 142 may be determined based on the emission requirements of the detection light and in combination with the lenses of the shared lens group 141. In some embodiments, the receiving lens group 143 may have 1 to 3 lenses.

[0100] In some embodiments as shown in FIG2 , the lenses of the receiving lens group 143 are all positive lenses, so that the receiving lens group 143 and the shared lens group 141 cooperate to converge the echo light. The receiving lens group 143 is a positive lens group, and 1 to 3 lenses in the receiving lens group 143 are all positive lenses.

[0101] The lenses in the receiving lens group 143 are all convex lenses that converge light. The focal length of the receiving lens group 143 is short, which can effectively compress the optical path length of the laser radar along the propagation direction of the echo light, which is conducive to the miniaturization of the laser radar.

[0102] In some embodiments, a filter 121 is further provided in the optical path upstream of the receiver 120 ; as shown in FIG. 1 and FIG. 2 , the filter 121 is located in the optical path between the receiving lens group 143 and the receiver 120 .

[0103] 5 , there is shown a functional block diagram of another embodiment of the laser radar disclosed herein.

[0104] With reference to FIG6 , FIG6 shows another optical path structure schematic diagram of a laser radar consistent with some embodiments of the present disclosure.

[0105] The present disclosure does not repeat the same aspects as the above embodiments. The differences from the above embodiments include that in some embodiments shown in Figures 5 and 6, the laser radar further includes: a transmitting reflector 245, which is located between the transmitting lens group 242 and the transmitter 210 to change the optical path of the detection light.

[0106] By setting up the transmitting reflector 245, the light path is redirected to other directions of the laser radar, thereby compressing the space occupied by the optical device in the laser radar.

[0107] In some embodiments as shown in FIG6 , the transmitter 210 generates a cross section of the optical path direction of the probe light parallel to the optical path direction of the echo light incident on the receiver 220 , and the probe light and the echo light are not coplanar.

[0108] It should be noted that some embodiments shown in Figures 5 and 6 are different from the aforementioned embodiments in that the scanner 260 includes a swinging mirror, which includes a reflecting surface 261 that swings back and forth. The swinging mirror can scan the detection light along a second direction, which intersects with the first direction. The swinging mirror scans the detection light along the second direction to form a horizontal field of view of the laser radar.

[0109] Figure 7 shows a schematic diagram of the correspondence between lasers and detectors in a lidar consistent with some embodiments of the present disclosure. In some embodiments of the present disclosure, receiver 220 includes: multiple detectors (for example, including detector 221a and detector 221b), and the multiple detectors correspond one-to-one with the multiple lasers (including laser 211a and laser 211b) of transmitter 210. Referring to Figure 7, for example, laser 211a corresponds to detector 221a, and laser 211b corresponds to detector 221b, and the corresponding laser's transmitting field of view matches the detector's receiving field of view. In some embodiments, multiple detectors 221 are arranged in an array; adjacent columns of detectors 221 are staggered along the column direction, or adjacent rows of detectors are staggered along the row direction. The column direction of the detector arrangement corresponds to a first direction, which corresponds to the vertical field of view of the lidar. The row direction of the detector arrangement corresponds to a second direction, which corresponds to the horizontal field of view of the lidar.

[0110] As shown in Figure 7, the multiple detectors of receiver 220 are arranged in an array. Multiple detectors 221a are arranged along columns, and multiple detectors 221b are arranged along columns. The columns containing detectors 221a and 221b are adjacent to each other along rows. Along the rows, no other detectors are positioned between the columns of detectors 221a and 221b. Along the columns, one detector 221a is positioned between two adjacent detectors 221b, and another detector 221b is positioned between two adjacent detectors 221a.

[0111] The multiple lasers of transmitter 210 correspond one-to-one with the multiple detectors. In some embodiments, as shown in FIG7 , multiple lasers 211a are arranged along the column direction, and multiple lasers 211b are arranged along the column direction. The columns formed by lasers 211a and the columns formed by lasers 211b are adjacent to each other along the row direction. Along the row direction, no other lasers are arranged between the columns formed by lasers 211a and the columns formed by lasers 211b. Furthermore, along the column direction, one laser 211a is located between two adjacent lasers 211b, and one laser 211b is located between two adjacent lasers 211a.

[0112] It should be noted that, in other embodiments of the present disclosure, detectors in adjacent rows may also be staggered along the row direction.

[0113] Referring to FIG8 , FIG8 shows a functional block diagram of another embodiment of the laser radar disclosed herein.

[0114] With reference to FIG9 , FIG9 shows another optical path structure schematic diagram of a laser radar consistent with some embodiments of the present disclosure.

[0115] The present disclosure will not elaborate on the similarities with the previous embodiments. The difference from the previous embodiments is that in some embodiments shown in Figures 8 and 9, the laser radar further includes: a receiving reflector 344, which is located between the receiving lens group 343 and the receiver 320 and is used to change the optical path of the echo light.

[0116] By setting the receiving reflector 344, the light path is redirected to other directions of the laser radar, thereby compressing the space occupied by the optical device of the laser radar.

[0117] In some embodiments as shown in FIG8 and FIG9 , the laser radar has a transmitting reflector 345 and a receiving reflector 344 , and the transmitting reflector 345 and the receiving reflector 344 make the detection light and the return light coplanar.

[0118] In some embodiments, the laser in the transmitter 310 and the detector in the receiver 320 can be disposed on the same circuit board 350. In some embodiments shown in Figures 8 and 9, the laser radar has a transmitting reflector 345 and a receiving reflector 344 so that the laser in the transmitter 310 and the detector in the receiver 320 can be disposed on the same circuit board.

[0119] In some embodiments, the scanner 360 includes: a plurality of reflective surfaces 362 , and the angles between the plurality of reflective surfaces 362 and the rotation axis 363 are the same.

[0120] As shown in Figures 8 and 9 , the polygon mirror 361 of the scanner 360 is a four-sided mirror having four reflective surfaces 362. The angles between the four reflective surfaces 362 and the rotation axis 363 are not all the same. For example, the angle between at least one of the four reflective surfaces 362 and the rotation axis 363 is different from the angles between the other reflective surfaces 362 and the rotation axis 163.

[0121] In some embodiments, the scanner 360 may have an even number of reflective surfaces 362, wherein adjacent reflective surfaces 362 have different angles with the rotation axis 363, while alternate reflective surfaces 362 have the same angle with the rotation axis 363. For example, as shown in FIG9 , in the multi-faceted rotating mirror 361 of the scanner 360, the angles of the four reflective surfaces 362 along the circumference of the rotation axis 363 with the rotation axis 363 are +1°, -1°, +1°, and -1°, respectively.

[0122] It should be noted that the positive and negative values ​​of the angle between the reflecting surface 362 and the rotating axis 363 indicate that the directions of the angles formed between the reflecting surface 362 and the rotating axis 363 are different. In some embodiments, when the upper edge of the reflecting surface is close to the rotating axis and the lower edge of the reflecting surface is away from the rotating axis, the angle between the reflecting surface and the rotating axis is positive. When the lower edge of the reflecting surface is close to the rotating axis and the upper edge of the reflecting surface is away from the rotating axis, the angle between the reflecting surface and the rotating axis is negative. For example, if the angle between the reflecting surface 362 and the rotating axis 363 is +1°, the angle between the reflecting surface 362 and the rotating axis 363 is 1°, the upper edge of the reflecting surface 362 is close to the rotating axis 363, and the lower edge of the reflecting surface 362 is away from the rotating axis 363. If the angle between the reflecting surface 362 and the rotating axis 363 is -1°, the angle between the reflecting surface 362 and the rotating axis 363 is 1°, the lower edge of the reflecting surface 362 is close to the rotating axis 363, and the upper edge of the reflecting surface 362 is away from the rotating axis 363.

[0123] In some embodiments shown in FIG9 , the scanner 360 can scan the detection light in the horizontal direction, and the rotation axis 363 of the polygon mirror 361 intersects the horizontal plane, for example, the rotation axis 363 is perpendicular to the horizontal plane. The vertical field of view of the laser radar is -13° to +13°.

[0124] In some embodiments of the present disclosure, the field of view of the laser radar includes: an edge area and a central area, the central area is located between the two edge areas; the detection light reflected by adjacent reflecting surfaces covers the central area; the detection light reflected by adjacent reflecting surfaces covers different edge areas.

[0125] The scanner 360 is used to scan the probe light horizontally. FIG10 shows a schematic diagram of the field of view of a laser radar consistent with some embodiments of the present disclosure. As shown in FIG10 , the vertical field of view formed by the emitted probe light includes: a central region 305c and edge regions 305m located on both sides of the central region 305c. For example, the vertical field of view of the central region 305c ranges from -9° to +9°, the vertical field of view of the lower edge region 305m ranges from -13° to -9°, and the vertical field of view of the upper edge region 305m ranges from +9° to +11°. The probe light reflected by adjacent reflective surfaces 362 can all cover the central region 305c. The probe light reflected by adjacent reflective surfaces 362 covers the upper edge region 305m and the lower edge region 305m, respectively. For example, the probe light reflected by one reflective surface 362 covers the upper edge region 305m, while the probe light reflected by another adjacent reflective surface 362 covers the lower edge region 305m. In some embodiments, the frame rate of the central area 305 c is higher, and the frame rate of the edge area 305 m is lower. The central area 305 c is a high frame rate area, and the edge area 305 m is a low frame rate area.

[0126] By setting the angles between the multiple reflecting surfaces 362 of the polygonal mirror 361 and the rotation axis 363, the field of view of the laser radar can be expanded.

[0127] Figure 11 shows another schematic diagram of lasers and detectors in a lidar consistent with some embodiments of the present disclosure. Continuing with reference to Figure 8 and in conjunction with Figure 11 , in some embodiments of the present disclosure, receiver 320 includes multiple detector groups, each of which includes multiple detectors 321 , each corresponding one-to-one to multiple lasers 311 of transmitter 310 .

[0128] As shown in Figure 11 , laser 311 of transmitter 310 can be a large-light-emitting laser, such as a VCSEL. The probe light generated by laser 311 has a large emitting area, and the echo light generated by the probe light reflected by an object can be received by multiple detectors 321 of the corresponding detector group.

[0129] In some embodiments, multiple detector groups are arranged along the row direction, and multiple detectors 321 in the same detector group are arranged along the column direction; detectors of adjacent detector groups are staggered along the column direction.

[0130] Figure 11 shows four detector groups of receiver 320, using detector group 322a and detector group 322b as examples. Detector group 322a and detector group 322b are arranged along the row direction x1. The multiple detectors 321 of detector group 322a are arranged along the column direction y1, while the multiple detectors 321 of detector group 322b are arranged along the column direction y1.

[0131] The detector group 322a and the detector group 322b are adjacent to each other along the row direction x1, and the multiple detectors 321 of the detector group 322a and the multiple detectors 321 of the detector group 322b are staggered along the column direction y1.

[0132] Thus, along the column direction y1 , the detectors 321 of one detector group 322 a are located between the detectors 321 of two adjacent detector groups 322 b , and the detectors 321 of one detector group 322 b are located between the detectors 321 of two adjacent detector groups 322 a .

[0133] In other embodiments, multiple detector groups may be arranged along the column direction, multiple detectors in the same detector group may be arranged along the row direction, and detectors of adjacent detector groups may be staggered along the row direction.

[0134] In other embodiments, the detector 321 of the receiver 320 can be a detector with a large photosensitive surface, such as a two-dimensional SPAD array. The detector 321 can receive echo light with a large photosensitive area. The transmitter 310 includes multiple laser groups, and the laser group includes multiple lasers 311. The multiple laser groups correspond one-to-one to the multiple detectors 321. The detection light generated by the multiple lasers 311 in the laser group is reflected by the object and the echo light formed is received by the corresponding detector 321.

[0135] It should also be noted that in the laser radar shown in Figure 11, a large emitting surface laser corresponds to multiple detectors 321 in a detector group. In other embodiments of the present disclosure, the laser radar may also add an optical device to reduce the emitting area of ​​the laser.

[0136] FIG12 shows a corresponding schematic diagram of another laser and detector in a laser radar consistent with some embodiments of the present disclosure. As shown in FIG12 , in some embodiments, the laser radar further includes: a homogenizer 470, which is located in the optical path of the detection light. In the laser radar, the light-emitting area of ​​the laser 411 in the transmitter 410 is relatively small. After the detection light generated by one laser 411 is homogenized by the homogenizer 470, a detection light with a larger light spot is formed to be emitted from the laser radar. The echo light formed by the emitted detection light after being reflected by the object is received by the multiple detectors 421 of the receiver 420.

[0137] In an embodiment of the present disclosure, the optical device includes a shared lens group and a transmitting lens group. The shared lens group can converge the return light to the receiver, and the transmitting lens group and the shared lens group can collimate the detection light. The shared lens group in the laser radar can reduce the number of non-shared optical devices at the transmitting and receiving ends of the laser radar, simplifying the laser radar structure and reducing the impact of the tolerance of the optical devices on the laser radar performance.

[0138] Furthermore, the optical center of the beam splitter is located within the aperture formed by the probe light passing through the transmitting lens group. The transmitting lens group compresses the divergence angle of the probe light generated by the transmitter. This arrangement of the beam splitter and transmitting lens group helps improve the transmission efficiency of the lidar.

[0139] Although the present disclosure is disclosed as above, the present disclosure is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope defined by the claims.

Claims

1. A lidar, characterized in that, Comprising: A transmitter and a receiver, the transmitter being configured to generate detection light, and the receiver being configured to receive the echo light formed by the reflection of the detection light by an object; A beam splitter configured to separate the optical path of the echo light from the optical path of the detection light; An optical device, the optical device comprising: A common lens group configured to transmit the detection light and the echo light; the common lens group is further configured to converge the echo light to the receiver; A transmitting lens group located in the optical path between the transmitter and the beam splitter, the transmitting lens group and the common lens group being configured to collimate the detection light.

2. The lidar according to claim 1, characterized in that, The optical center of the beam splitter is located within the aperture stop formed by the detection light passing through the transmitting lens group.

3. The lidar according to claim 2, wherein, The transmitter is located on the focal plane of the transmitting lens group.

4. The lidar according to claim 1, characterized in that, The transmitting lens group is configured to compress the divergence angle of the detection light generated by the transmitter.

5. The lidar according to claim 1, characterized in that, The detection light sequentially passes through the transmitting lens group and the common lens group to form a telecentric optical path.

6. The lidar according to claim 5, wherein, The angle between the principal ray of the detection light and the optical axis of the transmitting lens group is less than 5°.

7. The lidar according to any one of claims 1 to 6, characterized in that, The lenses of the transmitting lens group are all positive lenses.

8. The lidar according to any one of claims 1 to 6, characterized in that, The optical device further comprises: A receiving lens group located in the optical path between the receiver and the beam splitter, the receiving lens group and the common lens group cooperating to converge the echo light to the receiver.

9. The lidar according to claim 8, wherein The lenses of the receiving lens group are all positive lenses.

10. The lidar according to claim 8, characterized in that, The lidar further comprises: a receiving mirror located between the receiving lens group and the receiver to change the optical path of the echo light.

11. The lidar according to claim 1, wherein, The lidar further comprises: a transmitting mirror located between the transmitting lens group and the transmitter to change the optical path of the detection light.

12. The lidar according to claim 1, wherein The receiver comprises: 1 detector, the detector being a two-dimensional array detector, the two-dimensional array detector comprising: a plurality of detection areas, the plurality of detection areas corresponding one-to-one to the plurality of lasers of the transmitter.

13. The lidar according to claim 1, wherein The receiver comprises: a plurality of detectors corresponding one-to-one to the plurality of lasers of the transmitter.

14. The lidar according to claim 13, wherein, The plurality of detectors are arranged in an array; the detectors in adjacent columns are staggered along the column direction, or the detectors in adjacent rows are staggered along the row direction.

15. The lidar according to claim 1, wherein The receiver comprises a plurality of detector groups, one detector group of the plurality of detector groups comprising a plurality of detectors, the plurality of detector groups corresponding one-to-one to the plurality of lasers of the transmitter.

16. The lidar according to claim 15, wherein The groups are arranged in the row direction, the plurality of detectors in one detector group of the plurality of detector groups are arranged in the column direction, and the detectors in adjacent detector groups are staggered along the column direction; Or, The plurality of detector groups are arranged in the column direction, the plurality of detectors in one detector group of the plurality of detector groups are arranged in the row direction, and the detectors in adjacent detector groups are staggered along the row direction.

17. The lidar according to claim 15, characterized in that, The lidar further comprises: a light homogenizer located in the optical path of the detection light.

18. The lidar according to claim 1, characterized in that, The lasers in the transmitter and the detectors in the receiver are arranged on the same circuit board.

19. The lidar according to claim 1, wherein The beam splitter comprises an aperture mirror or a partial mirror.

20. The lidar according to claim 19, characterized in that, The optical center of the beam splitter is the center of the aperture of the aperture mirror; or, the optical center of the beam splitter is the center of the transmission region in the partial mirror.

21. The lidar according to claim 1, characterized in that, It further includes: A scanner configured to emit the detection light outside the lidar and receive the echo light and emit it to the beam splitter; The beam splitter transmits the detection light generated by the emitter to the scanner, and the beam splitter also transmits the echo light received by the scanner to the receiver.

22. The lidar according to claim 21, wherein, The scanner includes: at least one reflecting surface that moves around a rotation axis, and the angle between the reflecting surface and the rotation axis has a preset value.

23. The lidar according to claim 22, characterized in that, The scanner includes: a plurality of the reflecting surfaces, and the angles between the plurality of reflecting surfaces and the rotation axis are partially the same.

24. The lidar according to claim 23, wherein The field of view of the lidar includes: an edge region and a central region, and the central region is located between two of the edge regions; The detection light reflected by adjacent reflecting surfaces all covers the central region; The detection light reflected by adjacent reflecting surfaces covers different edge regions.

25. The lidar according to claim 23, characterized in that, The scanner has an even number of reflecting surfaces, wherein the angles between adjacent reflecting surfaces and the rotation axis are different, and the angles between the spaced-apart reflecting surfaces and the rotation axis are the same.

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