Lidar

Abstract

This invention provides a lidar, comprising: a first transmitting unit and a second transmitting unit configured to emit a first detection laser beam and a second detection laser beam respectively for detecting a target; a transmitting optical component and a receiving optical component, the transmitting optical component including a transmitting lens and the receiving optical component including a receiving lens; a first receiving unit and a second receiving unit configured to receive a first echo and a second echo reflected by the first detection laser beam and the second detection laser beam from the target object respectively and convert them into electrical signals, wherein the first detection laser beam and the second detection laser beam arrive at the transmitting lens after passing through different optical paths after being emitted from the first transmitting unit and the second transmitting unit respectively, and the first echo and the second echo arrive at the first receiving unit and the second receiving unit respectively after passing through different optical paths from the receiving lens respectively.

Description

[0001] This application is a divisional application of Chinese patent application No. 202110446511.6, filed on April 25, 2021, entitled "Lidar". Technical Field

[0002] This disclosure relates to the field of photoelectric detection technology, and in particular to a lidar that can balance both long-range and short-range detection performance. Background Technology

[0003] LiDAR (Light Detection and Ranging) is a radar system that uses laser beams to detect the position, velocity, and other characteristics of targets. It is an advanced detection method that combines laser technology with photoelectric detection technology. Due to its advantages such as high resolution, good concealment, strong resistance to active interference, good low-altitude detection performance, small size, and light weight, LiDAR is widely used in fields such as autonomous driving, intelligent transportation, drones, intelligent robots, and resource exploration.

[0004] Currently, there are two typical application scenarios for LiDAR used in autonomous driving. The first is long-range, small vertical field of view (FOV) measurement, typically requiring the detection of objects more than 150m away, with a vertical FOV of 15°-40°, used for fine detection of obstacles at medium to long distances. The second is short-range, large vertical FOV measurement, typically with a detection distance of 15m-50m and a vertical FOV of 80°-105°, used for blind spot detection at close range. These two applications are usually implemented using two separate LiDAR units, which are then installed together on platforms such as autonomous vehicles to achieve blind-spot-free detection at both near and far distances. Figure 1 As shown.

[0005] It would be incredibly valuable if both of these detection needs could be met by a single radar. However, these two needs place entirely different demands on radar design. To achieve the longest possible detection range, the detector's optical path needs to be designed with a long focal length. Conversely, to achieve a wide field of view, a short focal length is required.

[0006] If in a distance measuring radar (long focal length optical path, such as...) Figure 2a Adding a vertical field of view (FOV) directly to the detector (as shown) will significantly increase the height of the detector's receiving surface, such as... Figure 3a As shown, this significantly increases the height of the lidar, which is detrimental to improving the integration of the radar. If in a proximity radar (short focal length optical path, such as...) Figure 2b On the (as shown), add a central area harness (to ensure the resolution of the distance measurement), such as Figure 3b As shown, this makes it difficult to improve the beam size in the central region due to the limitation of the size of a single detector, and it is also difficult to improve the distance measurement capability under the short focal length optical path.

[0007] The content in the background section is merely technology known to the public and does not necessarily represent existing technology in this field. Summary of the Invention

[0008] In view of at least one deficiency of the prior art, the present invention provides a lidar comprising: The first transmitting unit and the second transmitting unit are configured to emit a first detection laser beam and a second detection laser beam, respectively, to detect the target object; A transmitting optical assembly and a receiving optical assembly, wherein the transmitting optical assembly includes a transmitting lens and the receiving optical assembly includes a receiving lens; and A first receiving unit and a second receiving unit are configured to receive, respectively, the first echo and the second echo reflected by the first and second detection laser beams from the target object, and convert them into electrical signals. The first and second detection laser beams are emitted from the first and second transmitting units respectively and arrive at the transmitting lens after traveling through different optical paths. The first and second echoes arrive at the first and second receiving units respectively from the receiving lens after traveling through different optical paths.

[0009] According to one aspect of the present invention, the first transmitting unit and the second transmitting unit are respectively disposed at different positions from the transmitting lens, and the first receiving unit and the second receiving unit are respectively disposed at different positions from the receiving lens.

[0010] According to one aspect of the present invention, the first transmitting unit includes a first laser array disposed on the focal plane of the transmitting lens; the second transmitting unit includes a second laser array, the distance between the second laser array and the transmitting lens being less than the focal length of the transmitting lens; the first receiving unit includes a first detector array disposed on the focal plane of the receiving lens; the second receiving unit includes a second detector array, the distance between the second detector array and the receiving lens being less than the focal length of the receiving lens.

[0011] According to one aspect of the present invention, the second transmitting unit includes a transmitting zoom lens disposed between the second laser array and the transmitting lens, wherein the second detection laser beam is emitted to the outside of the lidar after passing through the transmitting zoom lens and the transmitting lens; the second receiving unit includes a receiving zoom lens disposed between the second detector array and the receiving lens, wherein the second echo is incident on the second detector array after passing through the receiving lens and the receiving zoom lens.

[0012] According to one aspect of the present invention, the lidar further includes one or more transmitting reflectors and one or more receiving reflectors, wherein the first detection laser beam is reflected by the transmitting reflector and exits through the transmitting lens, and the first echo is reflected by the receiving reflector and incident on the first detector array.

[0013] According to one aspect of the present invention, the transmitting end reflector includes a transmitting end reflector with an opening, wherein the first detection laser beam is reflected by the transmitting end reflector with the opening and exits through the transmitting lens, and the second detection laser beam passes through the opening and exits through the transmitting lens; wherein the receiving end reflector includes a receiving end reflector with an opening, wherein the first echo is reflected by the receiving end reflector with the opening and is incident on the first detector array, and the second echo passes through the opening and is incident on the second detector array.

[0014] According to one aspect of the invention, the lidar has a rotating shaft and an optomechanical rotor rotatable about the rotating shaft, the optomechanical rotor including a first transmitting unit and a second transmitting unit, a transmitting end optical assembly and a receiving end optical assembly, a first receiving unit and a second receiving unit, wherein the optomechanical rotor is disposed above the rotating shaft, or the rotating shaft passes through the optomechanical rotor.

[0015] According to one aspect of the present invention, the transmitting optical component includes a first transmitting lens and a second transmitting lens, and the receiving optical component includes a first receiving lens and a second receiving lens. The first detection laser beam is emitted through the first transmitting lens, and the second detection laser beam is emitted through the second transmitting lens. The first echo is focused onto the first receiving unit through the first receiving lens, and the second echo is focused onto the second receiving unit through the second receiving lens.

[0016] According to one aspect of the invention, the lidar has a rotation axis, a first emitting lens and a second emitting lens are positioned approximately 180 degrees apart about the rotation axis, and a first receiving lens and a second receiving lens are positioned approximately 180 degrees apart about the rotation axis.

[0017] According to one aspect of the invention, the first transmitting lens and the first receiving lens comprise a telecentric lens group.

[0018] According to one aspect of the invention, the first and second probe laser beams correspond to different vertical field-of-view ranges of the lidar.

[0019] According to one aspect of the invention, the energy of the first detection laser beam is higher than that of the second detection laser beam.

[0020] According to one aspect of the present invention, both the first transmitting unit and the second transmitting unit include a plurality of lasers and a multi-channel driving chip, the plurality of lasers and the multi-channel driving chip being disposed on the same PCB board; both the first receiving unit and the second receiving unit include a plurality of detectors and a multi-channel front-end chip, the plurality of detectors and the multi-channel front-end chip being disposed on the same PCB board.

[0021] According to one aspect of the present invention, the lidar further includes a data processing unit coupled to the first transmitting unit and the second transmitting unit, as well as the first receiving unit and the second receiving unit, and fuses the detection results of the first detection laser beam and the second detection laser beam to generate a point cloud.

[0022] The embodiments of the present invention propose a scheme that can integrate small FOV for distance measurement and large FOV for near measurement. The lidar according to the embodiments of the present invention can achieve detection of large vertical field of view at close range and detection of small vertical field of view at long range while ensuring a compact structure. Attached Figure Description

[0023] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure. In the drawings: Figure 1 A schematic diagram illustrating the combined use of existing lidar for distance measurement and lidar for proximity measurement is shown. Figure 2a A schematic diagram of the long focal length optical path of a lidar used for distance measurement in a small vertical field of view is shown. Figure 2b A schematic diagram of a short focal length optical path for a lidar used for proximity measurement in a large vertical field of view is shown. Figure 3a A schematic diagram of the long focal length optical path of a lidar with a large vertical field of view that can perform both long-range and short-range measurements is shown. Figure 3b A schematic diagram of the short focal length optical path of a lidar with a large vertical field of view that can perform both long-range and short-range measurements is shown. Figure 4a A schematic diagram of the optical path structure on the transmitting side of a lidar according to an embodiment of the present invention is shown; Figure 4b A schematic diagram of the optical path structure on the transmitting side of a lidar according to an embodiment of the present invention is shown; Figure 4c A schematic diagram of the optical path structure of the receiving side of a lidar according to an embodiment of the present invention is shown; Figure 5 A top view schematic diagram of a lidar according to an embodiment of the present invention is shown, which has a dual focal length structure; Figure 6 A schematic diagram of a lidar according to another embodiment of the present invention is shown, wherein a plurality of reflectors are provided; Figure 7a A schematic diagram of a non-penetrating lidar is shown; Figure 7b A schematic diagram of a through-type lidar is shown; Figure 8 A schematic diagram of a lidar according to another embodiment of the present invention is shown; Figure 9 A telecentric lens assembly for lidar is shown according to an embodiment of the present invention; Figure 10a A transmitting unit according to an embodiment of the present invention is shown; and Figure 10b A receiving unit according to an embodiment of the present invention is shown. Detailed Implementation

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0029] Based on existing optoelectronic devices (lasers, detectors), in order to enable lidar to simultaneously achieve both long-range and short-range detection capabilities without significantly increasing the height of the radar, the inventors of this invention conceived of setting up multiple transmitting units and multiple receiving units in the lidar, for example, two transmitting units and two receiving units. One transmitting unit and one receiving unit are used to detect distant targets with a small field of view (FOV), while the other transmitting unit and another receiving unit are used to detect nearby targets with a large FOV. Both units have transmitting lenses and receiving lenses. Different detection laser beams emitted by the multiple transmitting units reach the transmitting lens after passing through different optical paths, and then exit into the surrounding environment. The echoes generated on the target object travel through the receiving lens to different receiving units via different optical paths. That is, the transmit / receive pair consisting of one transmitting unit and one receiving unit corresponds to different focal lengths compared to the transmit / receive pair consisting of another transmitting unit and another receiving unit. Thus, the lidar according to the embodiments of this invention can simultaneously integrate the functions of large FOV for short-range detection and small FOV for long-range detection.

[0030] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0031] Figure 4a , 4b Figures 4c and 4c show a schematic diagram of a lidar 100 according to an embodiment of the present invention, wherein... Figure 4a and 4b The optical path structure of the transmitting side of the lidar is shown. Figure 4c The optical path structure of the receiver side of the lidar is shown, and will be described in detail below with reference to the accompanying drawings.

[0032] like Figure 4a As shown, the lidar 100 includes a first transmitting unit 101 and a second transmitting unit 102 on its transmitting side. The first transmitting unit 101 includes a first laser array mounted on a circuit board for emitting a first detection laser beam L1. Similarly, the second transmitting unit 102 includes a second laser array mounted on a circuit board for emitting a second detection laser beam L2. The lasers in the first and second laser arrays may be vertical cavity surface-emitting lasers (VCSELs) or edge-emitting lasers (EELs).

[0033] The lidar 100 also includes a transmitting optical component for modulating, for example collimating, the first detection laser beam L1 and the second detection laser beam L2 before projecting them into the environment surrounding the lidar for detecting targets. Figure 4aAs shown, the transmitting optical assembly includes a transmitting lens 103, which is configured to collimate the first probe laser beam L1 and the second probe laser beam L2. Figure 4a As shown, the first detection laser beam L1 and the second detection laser beam L2 are emitted from the first transmitting unit 101 and the second transmitting unit 102, respectively, and arrive at the transmitting lens 103 after traveling through different optical paths. For example, the optical path traveled by the first detection laser beam L1 is greater than that traveled by the second detection laser beam L2.

[0034] To ensure that the first detection laser beam L1 and the second detection laser beam L2 have different optical path lengths, the first emitting unit 101 and the second emitting unit 102 can be positioned at different distances from the emitting lens 103. Preferably, the first laser array of the first emitting unit 101 is disposed on the focal plane of the emitting lens 103, and the distance between the second laser array of the second emitting unit 102 and the emitting lens 103 is less than the focal length of the emitting lens 103.

[0035] According to a preferred embodiment of the present invention, such as Figure 4a As shown, the lidar also includes a transmitter zoom lens 104, which is disposed between the second laser array of the second transmitting unit 102 and the transmitting lens 103. The second detection laser beam L2 is emitted to the outside of the lidar after passing through the transmitter zoom lens 104 and the transmitting lens 103. Figure 4a As shown, after the second detection laser beam L2 passes through the transmitting zoom lens 104, its direction or divergence changes to a certain extent, and then it is incident on the transmitting lens 103 and emitted outside the lidar. Preferably, the second laser array of the second transmitting unit 102 is located on the focal plane of the lens group formed by the transmitting zoom lens 104 and the transmitting lens 103, and the equivalent focal length of the lens group formed by the transmitting zoom lens 104 and the transmitting lens 103 is smaller than the focal length of the transmitting lens 103.

[0036] in addition, Figure 4a , 4b and Figure 4c Not only is this a schematic diagram of a lidar 100 according to one embodiment of the present invention, Figure 4a and 4bThis is also a schematic diagram of the coaxial arrangement of the first transmitting unit 101 and the second transmitting unit 102 on the transmitting side, meaning that both the first transmitting unit 101 and the second transmitting unit 102 are arranged along the optical axis OO of the transmitting lens 103. The coaxial arrangement of the first transmitting unit 101 and the second transmitting unit 102 can be achieved in different ways. For example, an opening can be made in the circuit board of the second transmitting unit 102, at the center of the transmitting end zoom lens 104, to allow the first detection laser beam L1 to pass through. Therefore, the first detection laser beam L1 is not modulated by the transmitting end zoom lens 104. In this case, the first laser array of the first transmitting unit 101 can be arranged more densely, located approximately in the middle of the circuit board; the second laser array of the second transmitting unit 102 can be arranged more sparsely, located approximately at the edge of the circuit board. Alternatively, or alternatively, such as... Figure 4b As shown, the second transmitting unit 102 can also be divided into two parts, spaced apart from each other, and the transmitting end zoom lens 104 can also be divided into two parts, spaced apart from each other. The area between the second transmitting unit 102 and the area between the transmitting end zoom lens 104 can be used to pass through the first detection laser beam L1. Alternatively, the above embodiments can be combined, for example, with an opening in the middle of the circuit board of the second transmitting unit 102, and the transmitting end zoom lens 104 divided into two parts, or vice versa.

[0037] Alternatively, those skilled in the art can also conceive of implementing the transmitter zoom lens 104 using a microlens array (MLA). For example, a microlens can be placed downstream of the optical path of each laser in the second laser array of the second transmitting unit 102, and the second probe laser beam L2 can be modulated by the microlens before being projected onto the transmitting lens 103. Other configuration methods are also possible, which will be described in detail in the following embodiments.

[0038] exist Figure 4a and 4bIn the structure, the emitting lens 103 can adopt a typical design for distance-measuring lidar, with a large focal length. The first laser array of the first emitting unit 101 is directly set at the focal plane of the emitting lens 103, which can easily achieve high beam resolution within a small field of view. A emitting zoom lens 104 is added at the second emitting unit 102. The focal length of the lens group formed by the emitting zoom lens 104 and the emitting lens 103 is smaller than that of the emitting lens 103, thus enabling close-range detection scanning with a large field of view. At the same time, the height of the laser emitting surface is not very high, thus achieving a compact structure. Preferably, the first detection laser beam L1 (distance-measuring beam) and the second detection laser beam L2 (near-measuring beam) do not overlap in the vertical field of view, and the emitted light from the lasers used for distance and distance measurement have different energies. According to a preferred embodiment of the present invention, the energy of the first detection laser beam L1 used for distance measurement is higher than the energy of the second detection laser beam L2 used for distance measurement.

[0039] like Figure 4c As shown, the lidar 100 includes a first receiving unit 105 and a second receiving unit 106 on its receiving side. The first receiving unit 105 includes a first detector array, and the second receiving unit 106 includes a second detector array. The first and second detector arrays may include various types of photodetectors, such as avalanche photodiodes (APDs), single-photon avalanche diodes (SPADs), or silicon photomultiplier tubes (SiPMs). After the first detection laser beam L1 and the second detection laser beam L2 undergo diffuse reflection on the target object, they generate a first echo L1' and a second echo L2', respectively, which return to the lidar and are converged by the receiving lens 107 onto the first receiving unit 105 and the second receiving unit 106. The first receiving unit 105 and the second receiving unit 106 are configured to receive the first echo L1' and the second echo L2', respectively, and convert them into electrical signals for subsequent circuitry to perform signal processing and analysis. The first echo L1' and the second echo L2' travel from the receiving lens 107 to the first receiving unit 105 and the second receiving unit 106 through different optical paths, respectively. For example, the optical path of the first echo L1' is greater than that of the second echo L2'.

[0040] To ensure that the first echo L1' and the second echo L2' reach the first receiving unit 105 and the second receiving unit 106 via different optical paths, the first receiving unit 105 and the second receiving unit 106 can be positioned at different distances from the receiving lens 107. For example, the first detector array of the first receiving unit 105 can be positioned at the focal plane of the receiving lens 107, and the distance between the second detector array of the second receiving unit 106 and the receiving lens 107 can be set to be less than the focal length of the receiving lens 107.

[0041] According to a preferred embodiment of the present invention, such as Figure 4c As shown, the lidar 100 also includes a receiving zoom lens 108 on the receiving side. The receiving zoom lens 108 is disposed between the second detector array of the second receiving unit 106 and the receiving lens 107. The second echo L2' is incident on the second detector array after passing through the receiving lens 107 and the receiving zoom lens 108. Figure 4c As shown, after the second echo L2' passes through the receiving zoom lens 108, its direction or divergence changes to a certain extent before it is incident on the second detector array. Preferably, the second detector array of the second receiving unit 106 is located on the focal plane of the lens group formed by the receiving zoom lens 108 and the receiving lens 107, and the equivalent focal length of the lens group formed by the receiving zoom lens 108 and the receiving lens 107 is smaller than the focal length of the receiving lens 107.

[0042] Alternatively, those skilled in the art may also conceive of implementing the receiving-end zoom lens 108 through a microlens array (MLA), for example, by setting a microlens upstream of the optical path of each detector in the second detector array of the second receiving unit 106 to modulate the second echo L2'.

[0043] in addition, Figure 4a , 4b and Figure 4c Not only is this a schematic diagram of a lidar 100 according to one embodiment of the present invention, Figure 4c Similarly, the schematic diagram shows the coaxial arrangement of the first receiving unit 105 and the second receiving unit 106 on the receiving side, meaning that both the first receiving unit 105 and the second receiving unit 106 are arranged along the optical axis O'O' of the receiving lens 107. Likewise, the coaxial arrangement of the first receiving unit 105 and the second receiving unit 106 can be achieved in different ways. For example, an opening can be made in the circuit board of the second receiving unit 106, at the center of the receiving zoom lens 108, to allow the first echo L1' to pass through. Therefore, the first echo L1' is not modulated by the receiving zoom lens 108. In this case, the first detector array of the first receiving unit 105 can be arranged more densely, located approximately in the middle of the circuit board; the second detector array of the second receiving unit 106 can be arranged more sparsely, located approximately at the edge of the circuit board.

[0044] Alternatively, the second receiving unit 106 can also be divided into two parts, spaced apart from each other, and the receiving zoom lens 108 can also be divided into two parts, spaced apart from each other. The spaced area between the second receiving unit 106 and the spaced area between the receiving zoom lens 108 can be used to pass through the first detection laser beam L1. Alternatively, the above embodiments can be combined, for example, with an opening in the middle of the circuit board of the second receiving unit 106, and the receiving zoom lens 108 divided into two parts, or vice versa.

[0045] Alternatively, those skilled in the art can also conceive of implementing the receiving-end zoom lens 108 using a microlens array (MLA). For example, a microlens can be placed upstream of the optical path of each detector in the second detector array of the second receiving unit 106, so that the second echo L2' of the receiving lens 107 is modulated by the microlens before being incident on the detector. Other configuration methods are also possible, which will be described in detail in the following embodiments.

[0046] The receiving lens 107 can adopt a typical design for long-range lidar, with a large focal length. The first detector array of the first receiving unit 105 can be directly positioned at the focal plane of the receiving lens 107, easily achieving high beam resolution within a small field of view (FOV). A receiving zoom lens 108 is added near the second receiving unit 106. The lens group formed by the receiving zoom lens 108 and the receiving lens 107 has a smaller focal length than that of the receiving lens 107, thus achieving a large FOV. Simultaneously, the height of the detector's receiving surface is not very high, resulting in a compact structure. According to a preferred embodiment of the present invention, the sensitivity of the first detector array of the first receiving unit 105 used for long-range measurement is higher than the sensitivity of the second detector array of the second receiving unit 106 used for short-range measurement.

[0047] The present invention Figure 4a , 4b and Figure 4c The lidar shown is a dual-focal-length lidar, enabling it to simultaneously perform both large vertical FOV (field of view) proximity measurement and small vertical FOV (field of view) distance measurement without significantly increasing its height. Specifically, two transmitting units are configured on the transmitting side of the lidar, transmitting a first detection laser beam (for distance measurement) and a second detection laser beam (for proximity measurement). Two receiving units are configured on the receiving side, receiving the echoes generated by the first and second detection laser beams, respectively used for distance and proximity measurement. One transmitting unit and one receiving unit form a transceiver pair (for distance measurement), and another transmitting unit and another receiving unit form a transceiver pair (for proximity measurement), each corresponding to a different focal length. This compact structure simultaneously achieves both distance and proximity measurement performance.

[0048] Figure 5 A top view schematic diagram of a lidar 100 according to an embodiment of the present invention is shown, which also has a dual-focal-length structure. Figure 4a , 4b and Figure 4c The difference is, Figure 5 The first transmitting unit 101 and the second transmitting unit 102 are not coaxially arranged, that is, they are not arranged along the optical axis OO of the transmitting lens 103. Similarly, the first receiving unit 105 and the second receiving unit 106 are not coaxially arranged, that is, they are not arranged along the optical axis O'O' of the receiving lens 107. Figure 5 As shown, the lidar 100, in addition to a first transmitting unit 101, a second transmitting unit 102, a transmitting lens 103, and a transmitting zoom lens 104, also includes a transmitting end reflector 109 on the transmitting side. The transmitting end reflector 109 is located between the first transmitting unit 101 and the transmitting lens 103, and is used to receive a first detection laser beam L1. The first detection laser beam L1 is reflected by the transmitting end reflector 109 and then emitted through the transmitting lens 103. The second detection laser beam L2 emitted by the second transmitting unit 102 is modulated by the transmitting zoom lens 104 and then emitted through the transmitting lens 103. Preferably, as... Figure 5 As shown, the second transmitting unit 102 and the transmitting zoom lens 104 are positioned to avoid the propagation path of the first detection laser beam L1. Both the first detection beam L1 and the second detection laser beam L2 are emitted towards the center of the lens. The first detection beam L1 and the second detection laser beam L2 are in the horizontal direction ( Figure 5 In the diagram, the direction of the plane is horizontal, and the direction perpendicular to the plane is vertical. There is a small angular difference (in...). Figure 4a , 4b and Figure 4c (The angle difference is 0), compared to Figure 4a , 4b and Figure 4c In the embodiments, Figure 5 The embodiment in the text, by setting up the reflector 109, enables the structure of the lidar transmitter side to be more compact (lower in height).

[0049] Similarly, on the receiving side, the lidar 100, in addition to including a first receiving unit 105, a second receiving unit 106, a receiving lens 107, and a receiving zoom lens 108, also includes a receiving end reflector 110. The receiving end reflector 110 is located between the first receiving unit 105 and the receiving lens 107, and is used to receive the first echo L1'. The first echo L1' is reflected by the receiving end reflector 110 and then incident on the first receiving unit 105. The second echo L2' is incident on the second receiving unit 106 after passing through the receiving lens 107 and the receiving zoom lens 108. Preferably, as... Figure 5As shown, the second receiving unit 106 and the receiving zoom lens 108 are positioned to avoid the propagation path of the first echo L1'. By setting the reflector 110, the structure of the lidar receiving side can be made more compact. The first receiving unit 105 and the second receiving unit 106 can share a signal processing unit.

[0050] Figure 5 In the embodiment shown, a reflector is provided on the transmitting side and the receiving side of the lidar, respectively. The present invention is not limited to this, and multiple reflectors can also be provided. In addition, reflectors can be provided to change the direction of the second detection laser beam L2 and the second echo L2', which are all within the protection scope of the present invention.

[0051] In such Figure 5 In the described embodiment, the laser array of the first transmitting unit 101 emits a ranging beam, which is reflected and refracted once by the transmitting end reflector 109, and then emitted by the transmitting lens 103 (main transmitting lens). The echo of the ranging beam after being reflected by an obstacle is received by the receiving lens 107 (main receiving lens), and after being reflected and refracted once by the receiving end reflector 110, it is detected by the detector array of the first receiving unit 105. Subsequently, it is processed by the subsequent processing unit to obtain ranging data. The above detection process corresponds to long-distance small FOV detection.

[0052] The laser array of the second transmitting unit 102 emits a proximity beam, which passes through the transmitting zoom lens 104 and then through the transmitting lens 103 before being emitted. The echo of the proximity beam, after being reflected by an obstacle, is received by the receiving lens 107, then through the receiving zoom lens 108, and finally detected by the detector array of the second receiving unit 106. The data is then processed by a subsequent processing unit to obtain ranging data. This detection process corresponds to short-range, large FOV detection. The readout signals from the detector arrays of the first receiving unit 105 and the second receiving unit 106 can share a signal processing unit.

[0053] Figure 6 A lidar according to another embodiment of the present invention is shown. Figure 6 The first transmitting unit 101 and the second transmitting unit 102 are also non-coaxially arranged, that is, not arranged along the optical axis OO of the transmitting lens 103. Similarly, the first receiving unit 105 and the second receiving unit 106 are also non-coaxially arranged, that is, not arranged along the optical axis O'O' of the receiving lens 107. Figure 5 The difference between the Chinese and other embodiments is that... Figure 6 The lidar in this embodiment has multiple reflectors. For example... Figure 6As shown, on the transmitting side of the lidar 100, in addition to the first transmitting unit 101, the second transmitting unit 102, the transmitting lens 103, and the transmitting zoom lens 104, it also includes a first transmitting end reflector 109 and a second transmitting end reflector 111. The first transmitting end reflector 109 and the second transmitting end reflector 111 are sequentially located between the first transmitting unit 101 and the transmitting lens 103, and are used to reflect the first detection laser beam L1. The first detection laser beam L1 is reflected sequentially by the first transmitting end reflector 109 and the second transmitting end reflector 111, and then exits through the transmitting lens 103. The second detection laser beam L2 emitted by the second transmitting unit 102 is modulated by the transmitting zoom lens 104, and then exits through the transmitting lens 103. Preferably, as... Figure 6 As shown, the first transmitting end reflector 109 is positioned to avoid the propagation path of the second detection laser beam L2. The second transmitting end reflector 111 is positioned on the propagation path of the second detection laser beam L2. An opening can be made in the second transmitting end reflector 111 to allow the second detection laser beam L2 to pass through it. The remaining portion of the second transmitting end reflector 111 is used to reflect the first detection laser beam L1, as shown in the diagram. Figure 6 shown.

[0054] Similarly, on the receiving side, the lidar 100, in addition to including a first receiving unit 105, a second receiving unit 106, a receiving lens 107, and a receiving zoom lens 108, also includes a first receiving end reflector 110 and a second receiving end reflector 112. The first receiving end reflector 110 and the second receiving end reflector 112 are sequentially located between the first receiving unit 105 and the receiving lens 107, and are used to reflect the first echo L1'. The first echo L1' is reflected sequentially by the second receiving end reflector 112 and the first receiving end reflector 110 before entering the first receiving unit 105. The second echo L2' enters the second receiving unit 106 after passing through the receiving lens 107 and the receiving zoom lens 108. Preferably, as... Figure 6 As shown, the first receiving end reflector 110 is positioned to avoid the propagation path of the second echo L2', and the second receiving end reflector 112 is positioned on the propagation path of the second echo L2'. An opening can be made in the second receiving end reflector 112 to allow the second echo L2' to pass through it. The remaining portion of the second receiving end reflector 112 is used to reflect the first echo L1', as shown below. Figure 6 shown.

[0055] According to a preferred embodiment of the present invention, as shown in FIG7, the lidar has a rotating shaft and an optomechanical rotor rotatable about the rotating shaft. Figure 4a , Figure 4b , Figure 4c , Figure 5 and Figure 6 The optical and electronic components of the lidar transmitter and receiver shown are all integrated into the optomechanical rotor. For example... Figure 7a As shown, the optomechanical rotor is positioned above the rotating shaft, meaning the lidar's rotating shaft does not protrude beyond the optomechanical rotor. This non-penetrating structure prevents the rotating shaft from extending into the optomechanical rotor, thus providing more space for optical and electronic components, or reducing the size of both the optomechanical system and the lidar while maintaining the same component count. Of course, this invention is not limited to lidars with a non-penetrating structure; the lidar's rotating shaft can also penetrate the optomechanical rotor, such as... Figure 7b As shown, the through-shaft structure is more conducive to rotational stability, and these are all within the scope of protection of this invention. Particularly preferred, Figure 5 The lidar in this embodiment has a non-through-axis structure. Figure 6 The lidar in this embodiment has a through-axis structure.

[0056] Figure 8 A lidar 200 according to another embodiment of the present invention is shown, in Figure 8 In this embodiment, the first and second detection laser beams emitted by the first and second transmitting units of the lidar are emitted after passing through different transmitting lenses. Correspondingly, the first and second echoes are received by the first and second receiving units through different receiving lenses. Similarly, the transceiver pair composed of the first transmitting unit and the first receiving unit (for distance measurement) and the transceiver pair composed of the second transmitting unit and the second receiving unit (for near measurement) correspond to different focal lengths. (Refer to the following...) Figure 8 Detailed description.

[0057] like Figure 8 As shown, the lidar 200 includes a first transmitting unit 201 and a second transmitting unit 202 on the transmitting side, configured to emit a first detection laser beam L1 and a second detection laser beam L2 respectively for detecting targets. The transmitting optical components include a first transmitting lens 203-1 and a second transmitting lens 203-2, respectively used to modulate the first detection laser beam L1 and the second detection laser beam L2 and project them to the outside of the lidar 200. Additionally, the lidar 200 also includes a first transmitting reflector 209 and a second transmitting reflector 211 on the transmitting side. The first transmitting reflector 209 and the second transmitting reflector 211 are sequentially disposed between the first transmitting unit 201 and the first transmitting lens 203-1, for sequentially reflecting the first detection laser beam L1. Those skilled in the art will readily understand that the first transmitting reflector 209 and the second transmitting reflector 211 are not essential; the transmitting reflectors may be omitted, or other numbers of transmitting reflectors may be used, as long as the optical path requirements and mechanical structure layout requirements are met. Figure 8In this process, the second detection laser beam L2 emitted by the second transmitting unit 202 is directly incident on the second transmitting lens 203-2, and exits after modulation (e.g., collimation). Alternatively, one or more reflectors can be placed between the second transmitting unit 202 and the second transmitting lens 203-2; these are all within the scope of this invention. Figure 8 As shown, the first emitting lens 203-1 and the second emitting lens 203-2 are arranged around the rotation axis of the lidar (e.g., Figure 8 (As shown by the black circle in the image) are roughly 180 degrees apart. Figure 8 The optical path structure for near-range measurement and the optical path structure for far-range measurement are independent of each other, compared to the structure of the previous embodiment. Figure 8 The structure is easier to assemble and adjust. Furthermore, the 180-degree relative arrangement facilitates design and subsequent signal processing, as the near and far measurement data have a 180-degree angular difference in the horizontal direction. For example, the first transmitting unit 201 is arranged on the focal plane of the first transmitting lens 203-1, and the second transmitting unit 202 is arranged on the focal plane of the second transmitting lens 203-2.

[0058] like Figure 8 As shown, the lidar 200 includes a first receiving unit 205 and a second receiving unit 206 on the receiving side, configured to receive the first echo L1' and the second echo L2' reflected by the first detection laser beam L1 and the second detection laser beam L2 from the target object, respectively, and convert them into electrical signals. The receiving end optical components include a first receiving lens 207-1 and a second receiving lens 207-2, respectively used to receive the first echo L1' and the second echo L2'. Figure 8 As shown, the first receiving lens 207-1 can be arranged next to the first transmitting lens 203-1, and the second receiving lens 207-2 can be arranged next to the second transmitting lens 203-2. Additionally, the lidar 200 also includes a first receiving end reflector 210 and a second receiving end reflector 212 on the receiving side. The first receiving end reflector 210 and the second receiving end reflector 212 are sequentially arranged between the first receiving unit 205 and the first receiving lens 207-1 to sequentially reflect the first echo L1'. Those skilled in the art will readily understand that the first receiving end reflector 210 and the second receiving end reflector 212 are not essential; receiving end reflectors may not be provided, or other numbers of receiving end reflectors may be provided, as long as the optical path requirements and mechanical structure layout requirements are met. Figure 8 In this process, the second echo L2' is directly converged to the second receiving unit 206 after passing through the receiving lens 207-2 and is converted into an electrical signal. Alternatively, one or more reflectors can be placed between the second receiving unit 206 and the second receiving lens 207-2; these are all within the scope of protection of this invention. Figure 8As shown, the first receiving lens 207-1 and the second receiving lens 207-2 revolve around the rotation axis of the lidar (e.g., Figure 8 (As shown by the black circle in the center) are roughly 180 degrees apart. The first receiving unit 205 is arranged, for example, on the focal plane of the first receiving lens 207-1, and the second receiving unit 206 is arranged, for example, on the focal plane of the second receiving lens 207-2. Figure 8 The lidar 200 shown can be either a through-axis structure or a non-through-axis structure, preferably a non-through-axis structure.

[0059] like Figure 8 As shown, the first detection laser beam L1 and the second detection laser beam L2 are emitted from the first transmitting unit 201 and the second transmitting unit 202, respectively, and arrive at the first transmitting lens 203-1 and the second transmitting lens 203-2 after passing through different optical paths. The first echo and the second echo arrive at the first receiving unit and the second receiving unit from the receiving lens after passing through different optical paths, respectively.

[0060] exist Figure 8 In one embodiment, the first transmitting lens 203-1 has, for example, a large focal length, and the first receiving lens 207-1 has, for example, a large focal length. Combined with the first transmitting unit 201 and the first receiving unit 205, they are used for long-distance small FOV detection. The second transmitting lens 203-2 has, for example, a small focal length, and the second receiving lens 207-2 has, for example, a small focal length. Combined with the second transmitting unit 202 and the second receiving unit 206, they are used for short-distance large FOV detection.

[0061] According to a preferred embodiment of the present invention, the lasers in the first transmitting unit 201 and the second transmitting unit 202 include vertical-cavity surface-emitting lasers (VCSELs), configured to emit light perpendicular to the PCB board. The detectors (arrays) in the first receiving unit 205 and the second receiving unit 206 include, for example, single-photon detectors (SiPMs) or SPAD arrays. Furthermore, the optoelectronic devices for proximity measurement and the optoelectronic devices for distance measurement can share a rotating platform, and are powered and transmit signals wirelessly. Preferably, in... Figure 8 In the embodiment shown, the lidar 200 is a non-through-axis structure (e.g., Figure 7a The structure shown indicates that the rotating axis of the lidar does not protrude from the rotor, in order to increase the space in the rotor to accommodate the proximity and distance measurement modules.

[0062] According to a preferred embodiment of the present invention, the first transmitting lens 203-1 and the first receiving lens 207-1 are preferably, for example, a telecentric lens group, such as... Figure 9The aforementioned design reduces the overall lens height, resulting in a more compact structure. A first field mirror 213 can be positioned downstream of the optical path of the first transmitting unit 201, near the focal plane of the first transmitting lens 203-1. A second field mirror 214 can be positioned upstream of the optical path of the first receiving unit 205, near the focal plane of the first receiving lens 207-1. By using the first field mirror 213 and the second field mirror 214, the optical path can be pulled back onto the optical axis. Simultaneously, the first transmitting lens 203-1 and the first receiving lens 207-1, used for distance measurement, have long focal lengths and small vertical field of view, while the second transmitting lens 203-2 and the second receiving lens 207-2, used for near distance measurement, have short focal lengths and large vertical field of view, yet their focal plane heights can be relatively close. Therefore, the height difference between the optical paths for distance and near distance measurement is not significant, resulting in a very compact and reasonable overall height for the lidar.

[0063] Preferably, the driving circuits for the laser arrays of the first transmitting units 101 and 201 and the second transmitting units 102 and 202 can be integrated onto a chip (multi-channel driving chip). For example, if the laser array includes 8 lasers, and the driving circuits for every 4 lasers are integrated onto one multi-channel driving chip, then the laser array and the two multi-channel driving chips correspond to each other. Multiple lasers and their corresponding multi-channel driving chips are disposed on the same PCB board. Figure 10a As shown. Preferably, the readout circuits of the detector arrays of the first receiving units 105, 205 and the second receiving units 106, 206 are also integrated into a chip (multi-channel analog front-end chip). For example, if the detector array includes 32 detectors, and the readout circuits of every 16 detectors are integrated into one multi-channel analog front-end chip, then the detector array corresponds to two multi-channel analog front-end chips. Multiple detectors and multi-channel analog front-end chips are disposed on the same PCB board, such as... Figure 10b As shown. In this way, the space occupied by the circuitry in the rotor can be further reduced, which is more conducive to accommodating the near and far measurement modules, making the lidar structure more compact.

[0064] The lidar of the present invention may further include a data processing unit, which is coupled to the first transmitting unit and the second transmitting unit, as well as the first receiving unit and the second receiving unit, and fuses the detection results of the first detection laser beam and the second detection laser beam to generate a point cloud.

[0065] As can be seen from the above embodiments, the present invention adopts a dual focal length separation design, which takes into account both high-resolution small FOV for distance measurement and low-resolution large FOV for proximity measurement. At the same time, the height of the laser and detector is not significantly increased, resulting in a compact structure that is beneficial for the installation of lidar on vehicles.

[0066] The lidar according to embodiments of the present invention integrates both large FOV (field of view) close-range detection and small FOV (field of view) long-range detection. By employing a zoom structure, the large FOV close-range detector does not need to be at the same focal length as the long-range detector, thereby significantly reducing the height of the detector panel. For the scheme using a shared main lens, the light rays from both the close-range and long-range detectors are emitted from the same set of transmitting and receiving main lenses. Therefore, the horizontal angle difference between the close-range and long-range detectors is very small, the time difference between the close-range and long-range detectors scanning the same object is small, and the point clouds from both detectors are easier to fuse.

[0067] This invention proposes a solution that can accommodate both small FOV distance measurement and large FOV proximity measurement. For the large FOV proximity detector, a zoom structure is adopted so that it does not have to be at the same focal length as the distance measurement detector. This greatly reduces the height of the large FOV proximity detector panel, thereby reducing the need for the lidar to be very tall and increasing the overall structural compactness.

[0068] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lidar, comprising: The first transmitting unit and the second transmitting unit are configured to emit a first detection laser beam and a second detection laser beam, respectively, to detect the target object; The transmitting optical component and the receiving optical component include a transmitting lens and a receiving optical component, respectively. and A first receiving unit and a second receiving unit are configured to receive, respectively, the first echo and the second echo reflected by the first and second detection laser beams from the target object, and convert them into electrical signals. The first and second detection laser beams are emitted from the first and second transmitting units respectively and arrive at the transmitting lens after passing through different optical paths. The first and second echoes are emitted from the receiving lens and arrive at the first and second receiving units respectively after passing through different optical paths. The lidar is configured to simultaneously perform near-field measurement with a large vertical field of view and far-field measurement with a small vertical field of view.

2. The lidar as claimed in claim 1, wherein the lidar has a rotating shaft and an optomechanical rotor rotatable about the rotating shaft, the optomechanical rotor including a first transmitting unit and a second transmitting unit, a transmitting end optical component and a receiving end optical component, a first receiving unit and a second receiving unit, wherein the optomechanical rotor is disposed above the rotating shaft, or the rotating shaft passes through the optomechanical rotor.

3. The lidar as claimed in claim 1, wherein the transmitting optical component includes a first transmitting lens and a second transmitting lens, the receiving optical component includes a first receiving lens and a second receiving lens, the first detection laser beam is emitted through the first transmitting lens, the second detection laser beam is emitted through the second transmitting lens; the first echo is converged to the first receiving unit through the first receiving lens, and the second echo is converged to the second receiving unit through the second receiving lens.

4. The lidar as described in claim 3 further includes one or more transmitting reflectors and one or more receiving reflectors, wherein the first detection laser beam is reflected by the transmitting reflector and then emitted through the first transmitting lens; the first echo is reflected by the receiving reflector and then incident on the first receiving unit.

5. The lidar of claim 3, wherein the lidar has a rotation axis, the first emitting lens and the second emitting lens are positioned approximately 180 degrees apart about the rotation axis, and the first receiving lens and the second receiving lens are positioned approximately 180 degrees apart about the rotation axis.

6. The lidar as described in any one of claims 3-5, wherein the first transmitting lens and the first receiving lens comprise a telecentric lens group.

7. The lidar as described in any one of claims 1, 3-5, wherein the first detection laser beam and the second detection laser beam correspond to different vertical field-of-view ranges of the lidar.

8. The lidar as described in any one of claims 1-5, wherein the energy of the first detection laser beam is higher than that of the second detection laser beam.

9. The lidar as described in any one of claims 1-5, wherein the first transmitting unit and the second transmitting unit each include a plurality of lasers and a multi-channel driving chip, the plurality of lasers and the multi-channel driving chip being disposed on the same PCB board; the first receiving unit and the second receiving unit each include a plurality of detectors and a multi-channel front-end chip, the plurality of detectors and the multi-channel front-end chip being disposed on the same PCB board.

10. The lidar as described in any one of claims 1-5 further includes a data processing unit, the data processing unit being coupled to the first transmitting unit and the second transmitting unit, as well as the first receiving unit and the second receiving unit, and fusing the detection results of the first detection laser beam and the second detection laser beam to generate a point cloud.

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