Lidar

Abstract

The application provides a laser radar, comprising: a first emission unit and a second emission unit configured to respectively emit a first probe laser beam and a second probe laser beam to probe a target object; a transmission end optical assembly and a receiving end optical assembly, the transmission end optical assembly comprising a transmission lens, and the receiving end optical assembly comprising a receiving lens; a first receiving unit and a second receiving unit configured to respectively receive a first echo and a second echo of the first probe laser beam and the second probe laser beam reflected by the target object and convert the first echo and the second echo into electrical signals, wherein the first probe laser beam and the second probe laser beam respectively pass through different optical paths after being emitted from the first emission unit and the second emission unit to reach the transmission lens, and the first echo and the second echo respectively pass through different optical paths from the receiving lens to reach the first receiving unit and the second receiving unit.

Description

Technical Field

[0001] 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

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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 As shown), add a central area harness (to ensure distance measurement resolution), 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.

[0006] 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

[0007] In view of at least one deficiency in the prior art, the present application provides a laser radar, comprising:

[0008] a first emission unit and a second emission unit configured to respectively emit a first probe laser beam and a second probe laser beam for probing a target object;

[0009] a transmission end optical assembly comprising a transmission lens and a receiving end optical assembly comprising a receiving lens; and

[0010] a first receiving unit and a second receiving unit configured to respectively receive a first echo and a second echo of the first probe laser beam and the second probe laser beam reflected by the target object and convert into electrical signals,

[0011] wherein the first probe laser beam and the second probe laser beam respectively pass through different optical paths after being emitted from the first emission unit and the second emission unit to reach the transmission lens, and the first echo and the second echo respectively pass through different optical paths after being reflected from the receiving lens to reach the first receiving unit and the second receiving unit.

[0012] According to an aspect of the present application, the first emission unit and the second emission unit are respectively arranged at different positions from the transmission lens, and the first receiving unit and the second receiving unit are respectively arranged at different positions from the receiving lens.

[0013] According to an aspect of the present application, the first emission unit comprises a first laser array arranged on a focal plane of the transmission lens, the second emission unit comprises a second laser array, the distance between the second laser array and the transmission lens is less than the focal length of the transmission lens, the first receiving unit comprises a first detector array arranged on a focal plane of the receiving lens, and the second receiving unit comprises a second detector array, the distance between the second detector array and the receiving lens is less than the focal length of the receiving lens.

[0014] According to an aspect of the present application, the second emission unit comprises a transmission end zoom lens arranged between the second laser array and the transmission lens, the second probe laser beam passes through the transmission end zoom lens and the transmission lens to be emitted outside the laser radar, the second receiving unit comprises a receiving end zoom lens arranged between the second detector array and the receiving lens, and the second echo passes through the receiving lens and the receiving end zoom lens to be incident on the second detector array.

[0015] According to an aspect of the present application, the laser radar further comprises one or more transmitting end mirrors and one or more receiving end mirrors, the first probe laser beam is emitted through the transmitting lens after being reflected by the transmitting end mirror, and the first echo is incident on the first detector array after being reflected by the receiving end mirror.

[0016] According to an aspect of the present application, the transmitting end mirror comprises a transmitting end mirror with an opening, wherein the first probe laser beam is emitted through the transmitting lens after being reflected by the transmitting end mirror with the opening, and the second probe laser beam passes through the opening and is emitted through the transmitting lens; wherein the receiving end mirror comprises a receiving end mirror with an opening, wherein the first echo is incident on the first detector array after being reflected by the receiving end mirror with the opening, and the second echo passes through the opening and is incident on the second detector array.

[0017] According to an aspect of the present application, the laser radar has a rotating shaft and an optical engine rotor rotatable around the rotating shaft, the optical engine rotor comprises the first and second transmitting units, transmitting end optical assembly and receiving end optical assembly, first and second receiving units, wherein the optical engine rotor is arranged above the rotating shaft, or the rotating shaft penetrates the optical engine rotor.

[0018] According to an aspect of the present application, the transmitting end optical assembly comprises first and second transmitting lenses, and the receiving end optical assembly comprises first and second receiving lenses, the first probe laser beam is emitted through the first transmitting lens, and the second probe 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.

[0019] According to an aspect of the present application, the laser radar has a rotating shaft, the first and second transmitting lenses are substantially opposite around the rotating shaft by 180 degrees, and the first and second receiving lenses are substantially opposite around the rotating shaft by 180 degrees.

[0020] According to an aspect of the present application, the first transmitting lens and the first receiving lens comprise a telecentric lens group.

[0021] According to an aspect of the present application, the first probe laser beam and the second probe laser beam correspond to different vertical field of view ranges of the laser radar.

[0022] According to an aspect of the present application, the energy of the first probe laser beam is higher than that of the second probe laser beam.

[0023] According to an aspect of the present application, the first transmitting unit and the second transmitting unit each comprise a plurality of lasers and a multi-channel driving chip, and the plurality of lasers and the multi-channel driving chip are arranged on the same PCB board; the first receiving unit and the second receiving unit each comprise a plurality of detectors and a multi-channel front-end chip, and the plurality of detectors and the multi-channel front-end chip are arranged on the same PCB board.

[0024] According to an aspect of the present application, the laser radar further comprises a data processing unit, which is coupled with the first transmitting unit and the second transmitting unit and 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.

[0025] Embodiments of the present application propose a scheme that can fuse small-FOV far-range detection and large-FOV near-range detection, and the laser radar according to the embodiments of the present application can realize near-range large-vertical-FOV detection and far-range small-vertical-FOV detection while ensuring a compact structure. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form a part of the disclosure, are intended to provide further understanding of the disclosure, and the illustrative embodiments of the disclosure and their description serve to explain the disclosure. The accompanying drawings in conjunction with the description below, do not constitute an inappropriate limitation on the disclosure. In the drawings:

[0027] Figure 1 A schematic diagram showing the combination use of an existing laser radar for far-range detection and a laser radar for near-range detection is shown;

[0028] Figure 2a A schematic diagram showing a long-focus optical path of a laser radar for small-vertical-FOV far-range detection is shown;

[0029] Figure 2b A schematic diagram showing a short-focus optical path of a laser radar for large-vertical-FOV near-range detection is shown;

[0030] Figure 3a A schematic diagram showing a long-focus optical path of a laser radar for large-vertical-FOV far-range and near-range detection is shown;

[0031] Figure 3b A schematic diagram showing a short-focus optical path of a laser radar for large-vertical-FOV far-range and near-range detection is shown;

[0032] Figure 4a A schematic diagram showing the optical path structure of the transmitting side of a laser radar according to an embodiment of the present application is shown;

[0033] Figure 4b A schematic diagram showing the optical path structure of the transmitting side of a laser radar according to an embodiment of the present application is shown;

[0034] A schematic diagram showing the optical path structure of the transmitting side of a laser radar according to an embodiment of the present application is shown;Figure 4c A schematic diagram of an optical path structure of a receiving side of a lidar according to one embodiment of the present application is shown;

[0035] Figure 5 A top view schematic diagram of a lidar according to one embodiment of the present application is shown, having a dual focal length structure;

[0036] Figure 6 A schematic diagram of a lidar according to another embodiment of the present application is shown, having multiple mirrors;

[0037] Figure 7a A schematic diagram of a non-penetrating lidar is shown;

[0038] Figure 7b A schematic diagram of a penetrating lidar is shown;

[0039] Figure 8 A schematic diagram of a lidar according to another embodiment of the present application is shown;

[0040] Figure 9 A telecentric lens group for a lidar according to one embodiment of the present application is shown;

[0041] Figure 10a A transmitting unit according to one embodiment of the present application is shown; and

[0042] Figure 10b A receiving unit according to one embodiment of the present application is shown. DETAILED DESCRIPTION

[0043] In the following, only certain exemplary embodiments are described in brief. As will be appreciated by those skilled in the art, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. The drawings and the description are therefore to be considered in an illustrative, rather than a restrictive, sense.

[0044] In the description of the application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements indicated thereby must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated thereby. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0045] In the description of the application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0046] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "under", "below" and "under" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0047] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For purposes of simplicity and clarity, the description is directed to specific examples and embodiments. However, one skilled in the art will understand that the application can be practiced with many modifications, alternatives and variations of the embodiments specifically recited and / or of the methods and materials described and illustrated herein beyond those specifically discussed. Accordingly, the following detailed description is not intended to limit the scope or application of the application as claimed.

[0048] On the basis of the existing photoelectric devices (laser, detector), in order to make the laser radar can take into account the performance of measuring far and near, and do not significantly increase the height of the radar, the inventor of the present application conceives that a plurality of transmitting units and a plurality of receiving units can be respectively arranged in the laser radar, for example, two transmitting units and two receiving units, one transmitting unit and one receiving unit are used to detect the target object at a long distance with a small FOV, and the other transmitting unit and the other receiving unit are used to detect the target object at a short distance with a large FOV, and the transmitting lens and the receiving lens are provided, wherein the different detection laser beams emitted by the plurality of transmitting units pass through different optical paths to reach the transmitting lens, and are emitted into the surrounding environment after passing through the transmitting lens, and the echoes generated on the target object pass through different optical paths to reach different receiving units through the receiving lens, that is, the transmitting-receiving pair composed of one transmitting unit and one receiving unit and the transmitting-receiving pair composed of the other transmitting unit and the other receiving unit correspond to different focal lengths, so that the laser radar according to the embodiment of the present application can simultaneously integrate the functions of large-FOV short-distance detection and small-FOV long-distance detection.

[0049] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not intended to limit the present application.

[0050] Figure 4a 、 4b and 4c show the schematic diagram of the laser radar 100 according to an embodiment of the present application, wherein Figure 4a and 4b show the optical path structure of the transmitting side of the laser radar, Figure 4c show the optical path structure of the receiving side of the laser radar, which are described in detail below with reference to the accompanying drawings.

[0051] As Figure 4aAs shown, the laser radar 100 comprises a first emission unit 101 and a second emission unit 102 at its emission side, wherein the first emission unit 101 comprises a first laser array arranged on a circuit board for emitting a first probe laser beam L1, and the second emission unit 102 also comprises a second laser array arranged on a circuit board for emitting a second probe laser beam L2. The lasers in the first laser array and the second laser array can comprise vertical cavity surface emitting lasers (VCSEL) or edge emitting lasers (EEL).

[0052] The laser radar 100 further comprises an emission end optical assembly for modulating, for example, collimating, the first probe laser beam L1 and the second probe laser beam L2 before they are emitted into the environment around the laser radar for detecting a target object. As shown, Figure 4a The emission end optical assembly comprises an emission lens 103 configured to collimate the first probe laser beam L1 and the second probe laser beam L2. As shown, Figure 4a As shown, the first probe laser beam L1 and the second probe laser beam L2 respectively exit from the first emission unit 101 and the second emission unit 102, and then reach the emission lens 103 after passing through different optical paths, wherein the optical path passed by the first probe laser beam L1 is, for example, longer than the optical path passed by the second probe laser beam L2.

[0053] In order to make the first probe laser beam L1 and the second probe laser beam L2 have different optical paths, for example, the first emission unit 101 and the second emission unit 102 can be respectively arranged at different positions from the emission lens 103. Preferably, the first laser array of the first emission unit 101 is arranged on the focal plane of the emission lens 103, and the distance between the second laser array of the second emission unit 102 and the emission lens 103 is less than the focal length of the emission lens 103.

[0054] According to a preferred embodiment of the present application, as shown, Figure 4a The laser radar further comprises an emission end zoom lens 104 arranged between the second laser array of the second emission unit 102 and the emission lens 103, and the second probe laser beam L2 exits outside the laser radar after passing through the emission end zoom lens 104 and the emission lens 103. As shown, Figure 4aAs shown, the second probe laser beam L2 passes through the emission end zoom lens 104, and its direction or divergence is changed, then it is incident to the emission lens 103 and is emitted outside the laser radar. Preferably, the second laser array of the second emission unit 102 is located on the focal plane of the lens group composed of the emission end zoom lens 104 and the emission lens 103, and the equivalent focal length of the lens group composed of the emission end zoom lens 104 and the emission lens 103 is less than the focal length of the emission lens 103.

[0055] In addition, Figure 4a , 4b and Figure 4c Not only is the schematic diagram of the laser radar 100 according to an embodiment of the present application, Figure 4a and 4b The same is a schematic diagram of the coaxial arrangement of the first emission unit 101 and the second emission unit 102 on the emission side, i.e. the first emission unit 101 and the second emission unit 102 are both arranged along the optical axis OO of the emission lens 103. The coaxial arrangement of the first emission unit 101 and the second emission unit 102 can be realized in different ways. For example, an opening can be made on the circuit board of the second emission unit 102, and a central opening is made on the emission end zoom lens 104, for the first probe laser beam L1 to pass through, so that the first probe laser beam L1 is not modulated by the emission end zoom lens 104. In this case, the first laser array of the first emission unit 101 can be arranged more densely, at a position approximately in the middle of the circuit board; the second laser array of the second emission unit 102 can be arranged more sparsely, at a position approximately at the edge of the circuit board. In addition or alternatively, as shown in Figure 4b the second emission unit 102 can also be divided into two parts, spaced apart from each other, and the emission end zoom lens 104 can also be divided into two parts, spaced apart from each other, and the region in the middle of the second emission unit 102 and the region in the middle of the emission end zoom lens 104 can be used for the first probe laser beam L1 to pass through. In addition, the above embodiments can also be combined, for example, the circuit board of the second emission unit 102 is opened in the middle, and the emission end zoom lens 104 is divided into two parts, or vice versa.

[0056] In addition, those skilled in the art can also conceive that the emission end zoom lens 104 can be realized by a microlens array MLA, for example, a microlens is arranged downstream of the optical path of each laser in the second laser array of the second emission unit 102, and the second probe laser beam L2 is modulated by the microlens before being projected to the emission lens 103. In addition to this, other arrangement modes can also be conceived, which will be described in detail in the following embodiments.

[0057] In Figure 4a and 4bIn the structure, the emission lens 103 can adopt a common design for the laser radar for measuring distance, the focal length is large, the first laser array of the first emission unit 101 is directly arranged at the focal plane of the emission lens 103, and high line beam and high resolution can be easily realized in a small FOV range. The second emission unit 102 is provided with an emission zoom lens 104, and the focal length of the lens group composed of the emission zoom lens 104 and the emission lens 103 is small, smaller than the focal length of the emission lens 103, so that the near distance detection scanning of large FOV can be realized, and the height of the emission surface of the laser will not be very high, so that a compact structure can be realized. Preferably, the first detection laser beam L1 (distance measuring light) and the second detection laser beam L2 (near measuring light) do not coincide in the vertical field of view, and the exit light of the laser for measuring near and measuring distance has different energy. According to a preferred embodiment of the present application, the energy of the first detection laser beam L1 for measuring distance is higher than the energy of the second detection laser beam L2 for measuring near.

[0058] As shown in Figure 4c The laser radar 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 detector array and the second detector array can include various types of photodetectors, such as avalanche photodiodes APD, single-photon avalanche diodes SPAD, or silicon photomultipliers SiPM. After the first detection laser beam L1 and the second detection laser beam L2 are diffusely reflected on the target object, first return L1' and second return L2' are respectively generated and returned to the laser radar, and are converged by a receiving lens 107 to 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 return L1' and the second return L2' respectively and convert them into electrical signals for subsequent signal processing and analysis by the circuit. Among them, the first return L1' and the second return L2' respectively pass through different optical paths from the receiving lens 107 to the first receiving unit 105 and the second receiving unit 106, wherein the optical path passed by the first return L1' is greater than the optical path passed by the second return L2', for example.

[0059] In order to make the first return L1' and the second return L2' respectively pass through different optical paths to the first receiving unit 105 and the second receiving unit 106, the first receiving unit 105 and the second receiving unit 106 can be respectively arranged at different positions from the receiving lens 107. For example, the first detector array of the first receiving unit 105 can be arranged 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 arranged to be less than the focal length of the receiving lens 107.

[0060] According to a preferred embodiment of the present application, as shown in Figure 4c The laser radar 100 further comprises a receiving-end zoom lens 108 at the receiving side, which is arranged between the second detector array of the second receiving unit 106 and the receiving lens 107, and the second echo L2' is incident on the second detector array after passing through the receiving lens 107 and the receiving-end zoom lens 108. As shown in Figure 4c After passing through the receiving-end zoom lens 108, the direction or divergence of the second echo L2' changes, and then 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 composed of the receiving-end zoom lens 108 and the receiving lens 107, and the equivalent focal length of the lens group composed of the receiving-end zoom lens 108 and the receiving lens 107 is less than the focal length of the receiving lens 107.

[0061] In addition, those skilled in the art can also conceive that the receiving-end zoom lens 108 is realized by a microlens array MLA, for example, a microlens is arranged on the light path upstream of each detector in the second detector array of the second receiving unit 106, for modulating the second echo L2'.

[0062] In addition, Figure 4a , 4b and Figure 4c Not only is the schematic diagram of the laser radar 100 according to an embodiment of the present application, Figure 4c but also is a schematic diagram of the coaxial arrangement of the first receiving unit 105 and the second receiving unit 106 at the receiving side, i.e. the first receiving unit 105 and the second receiving unit 106 are both arranged along the optical axis O'O' of the receiving lens 107. Similarly, the coaxial arrangement of the first receiving unit 105 and the second receiving unit 106 can be realized in different ways. For example, an opening can be made on the circuit board of the second receiving unit 106, and a central opening is made in the receiving-end zoom lens 108, for passing through the first echo L1', so that the first echo L1' is not modulated by the receiving-end zoom lens 108. In this case, the first detector array of the first receiving unit 105 can be arranged more densely, at a position substantially in the middle of the circuit board; and the second detector array of the second receiving unit 106 can be arranged more sparsely, at a position substantially at the edge of the circuit board.

[0063] Alternatively or additionally, the second receiving unit 106 can also be divided into two parts spaced apart from each other, and the receiving end zoom lens 108 can also be divided into two parts spaced apart from each other. The area in the middle of the second receiving unit 106 and the area in the middle of the receiving end zoom lens 108 can be used for the first probe laser beam L1 to pass through. Alternatively, the above embodiments can also be combined, for example, the second receiving unit 106 has a hole in the middle of the circuit board, and the receiving end zoom lens 108 is divided into two parts, or vice versa.

[0064] In addition, those skilled in the art can also conceive that the receiving end zoom lens 108 can be implemented by a microlens array MLA, for example, a microlens is arranged upstream of the light path of each detector in the second detector array of the second receiving unit 106, and the second echo L2' of the receiving lens 107 is modulated by the microlens before being incident on the detector. In addition, other arrangements can also be provided, which will be described in detail in the embodiments below.

[0065] The receiving lens 107 can adopt a design commonly used in laser radars for distance measurement, and has a large focal length. The first detector array of the first receiving unit 105 can be directly arranged at the focal plane of the receiving lens 107, so that high beam and high resolution can be easily achieved in a small FOV range. A receiving zoom lens 108 is arranged near the second receiving unit 106, and the focal length of the lens group composed of the receiving zoom lens 108 and the receiving lens 107 is smaller than the focal length of the receiving lens 107. Therefore, a large FOV can be achieved, and the height of the receiving surface of the detector is not very high, so that a compact structure can be achieved. According to a preferred embodiment of the present application, the sensitivity of the first detector array of the first receiving unit 105 for distance measurement is higher than the sensitivity of the second detector array of the second receiving unit 106 for proximity measurement.

[0066] The laser radar of the present application Figure 4a 、 4b and Figure 4c The laser radar shown in FIG. 1 is a laser radar with a double focal length structure, so that the laser radar 100 can simultaneously achieve the functions of large vertical FOV proximity measurement and small vertical FOV distance measurement, and the height of the laser radar does not increase significantly. Specifically, two transmitting units are arranged on the transmitting side of the laser radar, which are respectively used for transmitting a first probe laser beam (for distance measurement) and a second probe laser beam (for proximity measurement). Two receiving units are arranged on the receiving side, which are respectively used for receiving echoes generated by the first probe laser beam and the second probe laser beam, i.e., for distance measurement and proximity measurement. A transmitting unit and a receiving unit form a transmitting-receiving pair (for distance measurement), and another transmitting unit and another receiving unit form a transmitting-receiving pair (for proximity measurement), which correspond to different focal lengths. Thus, the laser radar can simultaneously achieve distance measurement and proximity measurement performance in a compact structure.

[0067] Figure 5 A top view of a laser radar 100 according to an embodiment of the present application is shown, also with a bifocal structure. Compared with Figure 4a , 4b and Figure 4c , Figure 5 the first and second transmitting units 101 and 102 are arranged non-coaxially, i.e. not along the optical axis O of the transmitting lens 103, and the first and second receiving units 105 and 106 are arranged non-coaxially, i.e. not along the optical axis O' of the receiving lens 107. As shown in Figure 5 , the laser radar 100 on the transmitting side comprises, in addition to the first and second transmitting units 101 and 102, the transmitting lens 103 and the transmitting zoom lens 104, a transmitting end mirror 109 between the first transmitting unit 101 and the transmitting lens 103 for receiving the first probe laser beam L1, which is reflected by the transmitting end mirror 109 and then exits through the transmitting lens 103. The second probe laser beam L2 transmitted by the second transmitting unit 102 is modulated by the transmitting zoom lens 104 and then exits through the transmitting lens 103. Preferably, as shown in Figure 5 , the second transmitting unit 102 and the transmitting zoom lens 104 are arranged to avoid the propagation path of the first probe laser beam L1, and the first and second probe laser beams L1 and L2 exit towards the lens center, and the first and second probe laser beams L1 and L2 have a small angle difference in the horizontal direction Figure 5 (the direction of the figure plane is the horizontal direction, and the direction perpendicular to the figure plane is the vertical direction), which is 0 in Figure 4a , 4b and Figure 4c , compared with the embodiments in Figure 4a , 4b and Figure 4c , Figure 5 the embodiment in can make the structure of the transmitting side of the laser radar more compact (lower in height) by arranging the mirror 109.

[0068] Similarly, on the receiving side, the laser radar 100 comprises, in addition to the first and second receiving units 105 and 106, the receiving lens 107 and the receiving zoom lens 108, a receiving end mirror 110 between the first receiving unit 105 and the receiving lens 107 for receiving the first echo L1', which is reflected by the receiving end mirror 110 and then incident on the first receiving unit 105. The second echo L2' passes through the receiving lens 107 and the receiving zoom lens 108 and is incident on the second receiving unit 106. Preferably, as shown in Figure 5The second receiving unit 106 and the receiving zoom lens 108 are arranged to avoid the propagation path of the first echo L1'. By arranging the mirror 110, the structure of the receiving side of the laser radar can be made more compact. The first receiving unit 105 and the second receiving unit 106 can share a signal processing unit.

[0069] Figure 5 In the illustrated embodiment, one mirror is arranged on the transmitting side and the receiving side of the laser radar respectively. The application is not limited thereto. A plurality of mirrors can also be arranged. In addition, the mirrors can be arranged to change the directions of the second probe laser beam L2 and the second echo L2' respectively. These are within the protection scope of the application.

[0070] In the embodiment as Figure 5 In the embodiment as

[0071] The laser array of the second transmitting unit 102 emits a near-range light beam, which is emitted through the transmitting zoom lens 104 and then through the transmitting lens 103. The echo of the near-range light beam reflected by an obstacle is received by the receiving lens 107 and then by the second receiving unit 106 through the receiving zoom lens 108. The probe detector array of the second receiving unit 106 then detects the echo, and the subsequent processing unit processes the echo to obtain ranging data. The above detection process corresponds to short-range large-FOV detection. The readout signals of the probe detector array of the first receiving unit 105 and the probe detector array of the second receiving unit 106 can share a signal processing unit.

[0072] Figure 6 A laser radar according to another embodiment of the application is shown, Figure 6 In the embodiment, the first transmitting unit 101 and the second transmitting unit 102 are also arranged non-coaxially, i.e., not along the optical axis OO of the transmitting lens 103, and the first receiving unit 105 and the second receiving unit 106 are also arranged non-coaxially, i.e., not along the optical axis O'O' of the receiving lens 107. In the embodiment, Figure 5 In the embodiment, Figure 6 The laser radar of the embodiment has a plurality of mirrors. As Figure 6As shown, on the emission side of the laser radar 100, in addition to comprising the first emission unit 101, the second emission unit 102, the emission lens 103 and the emission zoom lens 104, it further comprises a first emission end mirror 109 and a second emission end mirror 111, which are sequentially located between the first emission unit 101 and the emission lens 103, for reflecting the first probe laser beam L1, which is sequentially reflected by the first emission end mirror 109 and the second emission end mirror 111, and then emitted through the emission lens 103. The second probe laser beam L2 emitted by the second emission unit 102 is modulated by the emission zoom lens 104, and then emitted through the emission lens 103. Preferably, as shown in Figure 6 , the position of the first emission end mirror 109 is set to avoid the propagation path of the second probe laser beam L2, and the second emission end mirror 111 is arranged on the propagation path of the second probe laser beam L2. A hole can be opened on the second emission end mirror 111, so that the second probe laser beam L2 can pass through it, and the remaining positions of the second emission end mirror 111 are used to reflect the first probe laser beam L1, as shown in Figure 6 .

[0073] Similarly, on the receiving side, in addition to comprising the first receiving unit 105, the second receiving unit 106, the receiving lens 107 and the receiving zoom lens 108, the laser radar 100 further comprises a first receiving end mirror 110 and a second receiving end mirror 112, which are sequentially located between the first receiving unit 105 and the receiving lens 107, for reflecting the first echo L1', which is sequentially reflected by the second receiving end mirror 112 and the first receiving end mirror 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 shown in Figure 6 , the position of the first receiving end mirror 110 is set to avoid the propagation path of the second echo L2', and the second receiving end mirror 112 is arranged on the propagation path of the second echo L2'. A hole can be opened on the second receiving end mirror 112, so that the second echo L2' can pass through it, and the remaining positions of the second receiving end mirror 112 are used to reflect the first echo L1', as shown in Figure 6 .

[0074] According to a preferred embodiment of the present application, as shown in FIG. 7, the laser radar has a rotation shaft and an optical machine rotor rotatable around the rotation shaft, Figure 4a , Figure 4b , Figure 4c , Figure 5 andFigure 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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 for the rotor to accommodate the proximity and distance measurement modules.

[0081] 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 overall lens height can be reduced, and the structure is more compact. The first field mirror 213 can be arranged downstream of the light path of the first emission unit 201 and located near the focal plane of the first emission lens 203-1. The second field mirror 214 can be arranged upstream of the light path of the first receiving unit 205 and located near the focal plane of the first receiving lens 207-1. By arranging the first field mirror 213 and the second field mirror 214, the light path can be pulled back to the optical axis. Meanwhile, the focal length of the first emission lens 203-1 and the first receiving lens 207-1 for measuring distance is long, and the vertical field of view is small. The focal length of the second emission lens 203-2 and the second receiving lens 207-2 for measuring near is short, and the vertical field of view is large. The heights of the focal planes of the two are relatively close. Therefore, the heights of the light paths for measuring distance and measuring near are not much different, so that the overall height of the laser radar is very compact and reasonable.

[0082] In addition, preferably, the driving circuits of the laser arrays of the first emission unit 101, 201 and the second emission unit 102, 202 can be integrated on chips (multi-channel driving chips) respectively. For example, the laser array includes 8 lasers, and the driving circuits of every 4 lasers are integrated on 1 multi-channel driving chip. Then, the laser array and 2 multi-channel driving chips correspond to each other, and the plurality of lasers and the corresponding multi-channel driving chips are arranged on the same PCB board, as shown in FIG. 2. Figure 10a In addition, preferably, the driving circuits of the laser arrays of the first emission unit 101, 201 and the second emission unit 102, 202 can be integrated on chips (multi-channel driving chips) respectively. For example, the laser array includes 8 lasers, and the driving circuits of every 4 lasers are integrated on 1 multi-channel driving chip. Then, the laser array and 2 multi-channel driving chips correspond to each other, and the plurality of lasers and the corresponding multi-channel driving chips are arranged on the same PCB board, as shown in FIG. 2. Figure 10b In addition, preferably, the driving circuits of the laser arrays of the first emission unit 101, 201 and the second emission unit 102, 202 can be integrated on chips (multi-channel driving chips) respectively. For example, the laser array includes 8 lasers, and the driving circuits of every 4 lasers are integrated on 1 multi-channel driving chip. Then, the laser array and 2 multi-channel driving chips correspond to each other, and the plurality of lasers and the corresponding multi-channel driving chips are arranged on the same PCB board, as shown in FIG. 2.

[0083] The laser radar of the present application can further include a data processing unit coupled to the first emission unit and the second emission unit and 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.

[0084] As can be seen from the above embodiments, the present application adopts a double-focal-length separation design, which takes into account both high-resolution distance measurement and low-resolution near measurement, and at the same time, the height of the laser and the detector does not increase significantly, and the structure is compact, which is conducive to the installation of the laser radar on the vehicle.

[0085] The laser radar according to the embodiment of the present application integrates large-FOV near-distance detection and small-FOV long-distance detection. By using a zooming structure, the large-FOV near-distance detector does not have to be at the same focal length as the long-distance detector, so that the height of the detector panel is greatly reduced. For the scheme of sharing the main lens, the light rays of the near-distance detection and the long-distance detection are emitted from the same set of main transmitting and receiving lenses, so that the horizontal angle difference between the near-distance detection and the long-distance detection is small, the time difference of scanning the same object by the near-distance detection and the long-distance detection is small, and the point clouds of the near-distance detection and the long-distance detection are more easily fused.

[0086] The present application provides a scheme that can take into account both small-FOV long-distance detection and large-FOV near-distance detection. For the large-FOV near-distance detector, a zooming structure is used, so that the large-FOV near-distance detector does not have to be at the same focal length as the long-distance detector, so that the height of the large-FOV near-distance detector panel is greatly reduced, so that the height of the laser radar does not have to be made very high, and the compactness of the overall structure is increased.

[0087] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A lidar, comprising: a first emitting unit and a second emitting unit configured to emit a first probe laser beam and a second probe laser beam respectively to probe a target object; a transmitting end optical assembly and a receiving end optical assembly, the transmitting end optical assembly comprising a transmitting lens, the receiving end optical assembly comprising a receiving lens; and a first receiving unit and a second receiving unit configured to receive a first echo and a second echo of the first probe laser beam and the second probe laser beam reflected by the target object respectively and convert into electrical signals, wherein the first probe laser beam and the second probe laser beam respectively pass through different optical paths after being emitted from the first emitting unit and the second emitting unit to the transmitting lens, a lens modulating the first probe laser beam and a lens modulating the second probe laser beam are at least partially different, and the first echo and the second echo respectively pass through different optical paths from the receiving lens to the first receiving unit and the second receiving unit; wherein the lidar is configured to simultaneously achieve functions of large vertical field of view for near-range measurement and small vertical field of view for far-range measurement; wherein the first emitting unit comprises a first laser array, the first laser array being disposed on a focal plane of the transmitting lens; and the second emitting unit comprises a second laser array, a distance between the second laser array and the transmitting lens being less than a focal length of the transmitting lens. 2.The lidar of claim 1, wherein the first emitting unit and the second emitting 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. 3.The lidar of claim 1 or 2, wherein the first receiving unit comprises a first detector array, the first detector array being disposed on a focal plane of the receiving lens; and the second receiving unit comprises a second detector array, a distance between the second detector array and the receiving lens being less than a focal length of the receiving lens. 4.The lidar of claim 1 or 2, wherein the second emitting unit comprises a transmitting end zoom lens, the transmitting end zoom lens being disposed between the second laser array and the transmitting lens, the second probe laser beam passing through the transmitting end zoom lens and the transmitting lens to be emitted outside the lidar; and the second receiving unit comprises a receiving end zoom lens, the receiving end zoom lens being disposed between the second detector array and the receiving lens, the second echo passing through the receiving lens and the receiving end zoom lens to be incident on the second detector array. 5.The lidar of claim 4, further comprising one or more transmitting end mirrors and one or more receiving end mirrors, the first probe laser beam being reflected by the transmitting end mirrors to be emitted through the transmitting lens, and the first echo being reflected by the receiving end mirrors to be incident on the first detector array. ​ 6. The lidar of claim 5, wherein the transmitting end mirror comprises a transmitting end mirror with an aperture, wherein the first probe laser beam is transmitted out of the lidar through the transmitting lens after being reflected by the transmitting end mirror with the aperture, and the second probe laser beam passes through the aperture and is transmitted out of the lidar through the transmitting lens; wherein the receiving end mirror comprises a receiving end mirror with an aperture, wherein the first return is incident on the first detector array after being reflected by the receiving end mirror with the aperture, and the second return passes through the aperture and is incident on the second detector array.

7. The lidar of claim 1 or 2, wherein the lidar has a rotation shaft and an optical engine rotor rotatable around the rotation shaft, the optical engine rotor comprising the first and second transmitting units, the transmitting and receiving optical assemblies, and the first and second receiving units, wherein the optical engine rotor is disposed above the rotation shaft, or the rotation shaft penetrates through the optical engine rotor.

8. The lidar of claim 1, wherein the transmitting optical assembly comprises first and second transmitting lenses, and the receiving optical assembly comprises first and second receiving lenses, the first probe laser beam is transmitted out of the lidar through the first transmitting lens, and the second probe laser beam is transmitted out of the lidar through the second transmitting lens; the first return is focused onto the first receiving unit through the first receiving lens, and the second return is focused onto the second receiving unit through the second receiving lens.

9. The lidar of claim 8, wherein the lidar has a rotation axis, the first and second transmitting lenses are substantially opposite around the rotation axis by 180 degrees, and the first and second receiving lenses are substantially opposite around the rotation axis by 180 degrees.

10. The lidar of claim 8 or 9, wherein the first transmitting lens and the first receiving lens comprise a telecentric lens group.

11. The lidar of any one of claims 1, 2, 8, or 9, wherein the first probe laser beam and the second probe laser beam correspond to different vertical field of view ranges of the lidar.

12. The lidar of any one of claims 1, 2, 8, or 9, wherein the first probe laser beam has higher energy than the second probe laser beam.

13. The lidar of any one of claims 1, 2, 8, or 9, wherein the first and second transmitting units each comprise a plurality of lasers and a multi-channel driving chip, the plurality of lasers and the multi-channel driving chip are disposed on a same PCB board; and the first and second receiving units each comprise a plurality of detectors and a multi-channel front-end chip, the plurality of detectors and the multi-channel front-end chip are disposed on a same PCB board. ​ 14. The lidar of any one of claims 1, 2, 8, or 9, further comprising a data processing unit coupled with the first and second transmitting units and the first and second receiving units and fusing detection results of the first and second probe laser beams to generate a point cloud.

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