Laser radar

Abstract

The present invention relates to a laser beam splitter (LSP) that includes a first transmitting unit (101) and a second transmitting unit (102) configured to transmit a first detection laser beam (L1) and a second detection laser beam (L2), respectively, to detect a target, a transmitting end optical assembly (103) and a receiving end optical assembly (107), respectively, and a receiving end optical assembly (108) that receives a first echo (L1') and a second echo (L2') of the first detection laser beam (L1) and the second detection laser beam (L2), respectively, reflected by the target, and converts them into electrical signals. a first detection laser beam (L1) and a second detection laser beam (L2) are emitted from a first transmission unit (101) and a second transmission unit (102), respectively, and then reach a transmitting lens (103) via different optical paths, and a first echo (L1') and a second echo (L2') reach the first receiving unit (105) and the second receiving unit (106) via different optical paths from a receiving lens (107).

Description

[Technical field]

[0001] The present disclosure relates to the field of photoelectric detection technology, and more particularly to a laser radar capable of achieving both long-distance and short-distance detection performance. [Background technology]

[0002] Laser radar is a radar system that emits a laser beam to detect the target's position, speed, and other characteristics, and is an advanced detection method that combines laser technology and photoelectric detection technology. Laser radar has the advantages of high resolution, high secrecy, strong active interference prevention capabilities, excellent low-altitude detection performance, and is small and lightweight, so it is widely used in fields such as autonomous driving, intelligent road transportation, unmanned aerial vehicles, intelligent robots, and resource exploration.

[0003] Currently, laser radars used in autonomous driving have two typical application scenarios: one is long-distance measurement with a small vertical field of view (FOV), which usually requires detection of objects other than 150m, and the vertical FOV is 15°-40°, for high-precision detection of obstacles at medium to long distances; the other is short-distance measurement with a large vertical FOV, which usually requires detection distance of 15m-50m, and the vertical FOV is 80°-105°, for short-distance blind spot detection. As shown in Figure 1, these two applications are usually realized separately by two laser radars, and then implemented together on a platform such as an autonomous vehicle to achieve blind spot-free detection at long and short distances.

[0004] Being able to meet these two detection requirements with a single radar is extremely valuable. However, these two detection requirements place completely different design demands on the radar. To achieve the longest possible detection distance, the detector's optical path must be designed with a long focal length. On the other hand, to achieve a wide viewing angle, a short focal length must be adopted.

[0005] If one were to directly increase the vertical FOV for a long-range detection radar (using a long focal length optical path as shown in Figure 2a), the height of the detector's receiving surface would increase significantly, which would lead to a significant increase in the height of the laser radar, which is detrimental to improving the integration of the radar, as shown in Figure 3a. If one were to increase the beamline in the central region (ensuring long-range detection resolution) for a short-range detection radar (using a short focal length optical path as shown in Figure 2b), it would be difficult to increase the beamline in the central region due to size constraints on a single detector, as shown in Figure 3b, and it would also be difficult to improve long-range detection capability with a short focal length optical path.

[0006] The contents of the Background section are merely intended to disclose known technology and are not, of course, representative of the prior art in this field. Summary of the Invention

[0007] In view of at least one shortcoming of the prior art, the present invention provides a method for manufacturing a semiconductor device comprising: a first transmitting unit and a second transmitting unit configured to transmit a first detecting laser beam and a second detecting laser beam, respectively, for detecting a target; a transmitting end optical assembly and a receiving end optical assembly including a transmitting lens and a receiving lens, respectively; a first receiving unit and a second receiving unit configured to receive first and second echoes of the first and second detection laser beams reflected by a target and convert them into electrical signals, The first and second detection laser beams are emitted from the first and second transmitting units, respectively, and then reach the transmitting lens via different optical paths, and the first and second echoes reach the first and second receiving units via different optical paths from the receiving lens.

[0008] According to one aspect of the present invention, the first transmitting unit and the second transmitting unit are each provided at a different position from the transmitting lens, and the first receiving unit and the second receiving unit are each provided at a different position from the receiving lens.

[0009] According to one embodiment of the present invention, the first transmitting unit includes a first laser array disposed in a focal plane of the transmitting lens, the second transmitting unit includes a second laser array whose distance from the transmitting lens is smaller than a focal length of the transmitting lens, the first receiving unit includes a first detector array disposed in a focal plane of the receiving lens, and the second receiving unit includes a second detector array whose distance from the receiving lens is smaller than a focal length of the receiving lens.

[0010] According to one embodiment of the present invention, the second transmitting unit includes a transmitting end zoom lens provided between the second laser array and the transmitting lens, and the second detection laser beam is emitted to the outside of the laser radar through the transmitting end zoom lens and the transmitting lens, and the second receiving unit includes a receiving end zoom lens provided between the second detector array and the receiving lens, and the second echo is incident on the second detector array through the receiving lens and the receiving end zoom lens.

[0011] According to one embodiment of the present invention, the laser radar further comprises one or more transmitting end reflectors and one or more receiving end reflectors, the first detection laser beam is reflected by the transmitting end reflector and then emitted through the transmitting lens, and the first echo is reflected by the transmitting end reflector and then incident on the first detector array.

[0012] According to one embodiment of the present invention, the transmitting end reflector includes a transmitting end reflector having an aperture, wherein the first detection laser beam is reflected by the transmitting end reflector having the aperture and then emitted through the transmitting lens, and the second detection laser beam passes through the aperture and is emitted through the transmitting lens, and the receiving end reflector includes a receiving end reflector having an aperture, wherein the first echo is reflected by the receiving end reflector having the aperture and then incident on the first detector array, and the second echo passes through the aperture and is incident on the second detector array.

[0013] According to one aspect of the present invention, the laser radar comprises a rotation axis and an optical rotor rotatable around the rotation axis, the optical rotor including the first and second transmitting units, a transmitting end optical assembly and a receiving end optical assembly, and a first and second receiving unit, wherein the optical rotor is disposed above the rotation axis or the rotation axis passes through the optical rotor.

[0014] According to one aspect of the present invention, the transmitting end optical assembly includes a first transmitting lens and a second transmitting lens, and the receiving end optical assembly includes a first receiving lens and a second receiving lens, the first detection laser beam is emitted by the first transmitting lens, the second detection laser beam is emitted by the second transmitting lens, the first echo is focused on the first detection unit by the first receiving lens, and the second echo is focused on the second detection unit by the second receiving lens.

[0015] According to one embodiment of the present invention, the laser radar has a rotation axis, the first transmitting lens and the second transmitting lens are opposed to each other by approximately 180 degrees around the rotation axis, and the first receiving lens and the second receiving lens are opposed to each other by approximately 180 degrees around the rotation axis.

[0016] According to one aspect of the invention, the first transmitting lens and the first receiving lens include telecentric lens groups.

[0017] According to one aspect of the present invention, the first and second detection laser beams correspond to different vertical viewing ranges of the laser radar.

[0018] According to one embodiment of the invention, the energy of the first detection laser beam is higher than the energy of the second detection laser beam.

[0019] According to one aspect of the present invention, both the first transmitting unit and the second transmitting unit include multiple lasers and multi-channel driver chips mounted on the same PCB board, and both the first receiving unit and the second receiving unit include multiple detectors and multi-channel front-end chips mounted on the same PCB board.

[0020] According to one embodiment of the present invention, the laser radar further includes a data processing unit coupled to the first transmitting unit and the second transmitting unit and the first receiving unit and the second receiving unit, and configured to fuse detection results of the first detection laser beam and the second detection laser beam to generate a point cloud.

[0021] An embodiment of the present invention proposes a solution that can combine long-distance detection with a small FOV and short-distance detection with a large FOV. The laser radar of the embodiment of the present invention can ensure a compact structure while realizing short-distance detection with a large vertical field of view and long-distance detection with a small vertical field of view. [Brief description of the drawings]

[0022] Some of the drawings constituting the present disclosure are intended to facilitate a further understanding of the present disclosure, and the illustrative embodiments and the description thereof are intended to interpret the present disclosure and are not intended to unduly limit the present invention. The description of the drawings will be given below.

[0023] [Figure 1] FIG. 1 is a schematic diagram showing the combined use of a conventional long-distance detection laser radar and a short-distance detection laser radar. [Figure 2a] FIG. 1 is a schematic diagram showing the long focal length optical path of a laser radar for long-range detection with a small vertical FOV. [Figure 2b] FIG. 1 is a schematic diagram showing the short focal length optical path of a laser radar for close-range detection with a large vertical FOV. [Figure 3a] This is a schematic diagram showing the long focal length optical path of a laser radar that achieves both long-distance and short-distance detection with a large vertical FOV. [Figure 3b] This is a schematic diagram showing the short focal length optical path of a laser radar that achieves both long-distance and short-distance detection with a large vertical FOV. [Figure 4a] 1 is a schematic diagram showing an optical path structure on the transmission side of a laser radar according to one embodiment of the present invention. [Figure 4b] 1 is a schematic diagram showing an optical path structure on the transmission side of a laser radar according to one embodiment of the present invention. [Figure 4c] 1 is a schematic diagram showing an optical path structure on the receiving side of a laser radar according to one embodiment of the present invention. [Diagram 5] FIG. 1 is a schematic plan view of a laser radar having a dual focal length structure according to one embodiment of the present invention. [Figure 6] FIG. 13 is a schematic diagram showing a laser radar having multiple reflectors according to another embodiment of the present invention. [Figure 7a] FIG. 1 is a schematic diagram showing a non-penetrating laser radar. [Figure 7b] FIG. 1 is a schematic diagram showing a penetrating laser radar. [Figure 8] FIG. 13 is a schematic diagram showing a laser radar according to another embodiment of the present invention. [Figure 9] 1 shows a telecentric lens group for a laser radar according to one embodiment of the present invention. [Figure 10a] 1 illustrates a transmission unit according to one embodiment of the present invention. [Figure 10b] 2 illustrates a receiving unit according to one embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the following, only some exemplary embodiments are briefly described. It is obvious to those skilled in the art that the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature, rather than restrictive.

[0025] In describing the present invention, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., are based on the orientations or positional relationships shown in the drawings, and are merely for the purpose of easily explaining the present invention and simplifying the description, and do not express or imply that the devices or elements described necessarily have a particular orientation or are constructed or operated in a particular orientation, and should not be understood as limiting the present invention. In addition, the terms "first" and "second" are merely for descriptive purposes, and should not be understood as expressing or implying a relative importance or implying a number of technical features expressed. Thus, a feature qualified as "first" or "second" may expressly or imply that it includes one or more of the feature. In describing the present invention, unless otherwise specified, "plurality" means two or more than two.

[0026] In the description of the present invention, it should be understood that unless otherwise clearly specified or limited, the terms "attach", "couple" and "connect" should be understood in a broad sense, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, or in communication with each other, directly connected, indirectly connected through an intermediate medium, internal communication between two elements, or an interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific situation.

[0027] In the present invention, unless otherwise clearly defined or limited, a first feature being "above" or "below" a second feature may include a case where the first and second features are in direct contact with each other, or may include a case where the first and second features are not in direct contact with each other, but are in contact with each other through another feature between them. Furthermore, a first feature being "above," "above," and "on the upper surface" of a second feature may include a case where the first feature is directly above and diagonally above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. A first feature being "below," "below," and "below" a second feature may include a case where the first feature is directly below and diagonally below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0028] In the following disclosure, various embodiments or examples are provided to realize different structures of the present invention. In order to simplify the disclosure of the present invention, specific example components and configurations are described below. Of course, these are merely exemplary and are not intended to limit the present invention. In addition, the present invention may use repeated reference numerals and / or characters in different examples, but such repetition is for the sake of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. It should be noted that the present invention provides examples of various specific processes and materials, but those skilled in the art may envision the application of other processes and / or the use of other materials.

[0029] In order to make the laser radar compatible with long-distance detection performance and short-distance detection performance without significantly increasing the height under the conventional photoelectric device (laser, detector), the inventor of the present invention provides a laser radar with multiple transmission units and multiple receiving units, for example, two transmission units and two receiving units, one transmission unit and one receiving unit for detecting long-distance targets with a small FOV, another transmission unit and another receiving unit for detecting short-distance targets with a large FOV, and provides a transmission lens and a receiving lens, among which multiple Different detection laser beams emitted from multiple transmitting units reach the transmitting lens via different optical paths and are emitted into the surrounding environment through the transmitting lens, and echoes generated on the target reach different receiving units via different optical paths from the receiving lens; in other words, a transmitting / receiving pair consisting of one transmitting unit and one receiving unit and a transmitting / receiving pair consisting of another transmitting unit and another receiving unit correspond to different focal lengths, thereby arriving at the idea that the laser radar according to the embodiment of the present invention can integrate both the functions of short-distance detection with a large FOV and long-distance detection with a small FOV.

[0030] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. It should be understood that the preferred embodiments described in this specification are merely for the purpose of explaining and interpreting the present invention, and are not intended to limit the present invention.

[0031] 4a, 4b and 4c are diagrams showing the principle of a laser radar 100 according to one embodiment of the present invention, in which Fig. 4a and 4b show the optical path structure on the transmitting side of the laser radar, and Fig. 4c shows the optical path structure on the receiving side of the laser radar. A detailed description will be given below with reference to the drawings.

[0032] 4a, the laser radar 100 includes a first transmitting unit 101 and a second transmitting unit 102 on the transmitting side, in which the first transmitting unit 101 includes a first laser array mounted on a circuit board for transmitting a first detection laser beam L1, and the second transmitting unit 102 similarly includes a second laser array mounted on a circuit board for transmitting a second detection laser beam L2. The lasers in the first and second laser arrays may include vertical cavity surface emitting lasers (VCSELs) or edge emitting lasers (EELs).

[0033] The laser radar 100 further includes a transmitting end optical assembly for modulating, for example collimating, the first detection laser beam L1 and the second detection laser beam L2 and emitting them to the environment around the laser radar to detect a target. As shown in Fig. 4a, the transmitting end optical assembly includes a transmitting lens 103, which is configured to collimate the first detection laser beam L1 and the second detection laser beam L2. As shown in Fig. 4a, 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 then reach the transmitting lens 103 via different optical paths, where the optical path traveled by the first detection laser beam L1 is longer than the optical path traveled by the second detection laser beam L2, for example.

[0034] For example, the first transmitting unit 101 and the second transmitting unit 102 may be disposed at different positions from the transmitting lens 103, so that the first detecting laser beam L1 and the second detecting laser beam L2 have different optical paths. Preferably, the first laser array of the first transmitting unit 101 is disposed at the focal plane of the transmitting lens 103, and the distance between the second laser array of the second transmitting unit 102 and the transmitting lens 103 is smaller than the focal length of the transmitting lens 103.

[0035] According to a preferred embodiment of the present invention, as shown in FIG. 4a, the laser radar further includes a transmitting end zoom lens 104 disposed between the second laser array of the second transmitting unit 102 and the transmitting lens 103, and the second detection laser beam L2 passes through the transmitting end zoom lens 104 and the transmitting lens 103 to be emitted to the outside of the laser radar. As shown in FIG. 4a, after the second detection laser beam L2 passes through the transmitting end zoom lens 104, a certain change occurs in its direction or divergence, and the second detection laser beam L2 is incident on the transmitting lens 103 and emitted to the outside of the laser radar. Preferably, the second laser array of the second transmitting unit 102 is located at the focal plane of the lens group consisting of the transmitting end zoom lens 104 and the transmitting lens 103, and the equivalent focal length of the lens group consisting of the transmitting end zoom lens 104 and the transmitting lens 103 is smaller than the focal length of the transmitting lens 103.

[0036] In addition, Fig. 4a, 4b and 4c are not only a principle diagram of the laser radar 100 according to one embodiment of the present invention, but also a schematic diagram showing the coaxial arrangement of the first transmitting unit 101 and the second transmitting unit 102 at the transmitting side, that is, the first transmitting unit 101 and the second transmitting unit 102 are both 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 realized by different ways. For example, an opening can be opened in the circuit board of the second transmitting unit 102 to pass the first detection laser beam L1, and an opening can be opened in the center of the zoom lens 104 at the transmitting end, so that the first detection laser beam L1 is not modulated by the zoom lens 104 at the transmitting end. In this case, the first laser array of the first transmitting unit 101 can be densely arranged at approximately the middle position of the circuit board. The second laser array of the second transmitting unit 102 can be sparsely arranged at approximately the edge position of the circuit board. 4b, the second transmitting unit 102 may be divided into two parts, an upper part and an lower part, and separated from each other, and the transmitting end zoom lens 104 may be divided into two parts and separated from each other, and the intermediate space of the second transmitting unit 102 and the intermediate space of the transmitting end zoom lens 104 may be used to pass the first detection laser beam L1. Also, the above embodiments may be combined, for example, a hole may be drilled in the middle of the circuit board of the second transmitting unit 102, and the transmitting end zoom lens 104 may be divided into two parts, or vice versa.

[0037] Those skilled in the art may also consider implementing the transmitting end zoom lens 104 by a microlens array MLA, for example, by providing a microlens downstream of the optical path of each laser in the second laser array of the second transmitting unit 102, the second detection laser beam L2 is modulated by the microlens before being projected to the transmitting lens 103. In addition, other installation methods may be considered, which will be described in detail in the following embodiments.

[0038] In the structure of Figures 4a and 4b, the transmitting lens 103 may adopt the design of a normal long-distance detection laser radar, with a large focal length, and the first laser array of the first transmitting unit 101 is directly mounted on the focal plane of the transmitting lens 103, so that it is easy to achieve high beamline resolution within a small FOV range. A transmitting zoom lens 104 is added to the second transmitting unit 102, and the focal length of the lens group consisting of the transmitting zoom lens 104 and the transmitting lens 103 is small, which is smaller than the focal length of the transmitting lens 103, so that short-distance detection scanning can be realized with a large FOV, and at the same time, the height of the light emitting surface of the laser is not high, so that a compact structure can be realized. It is preferable that the first detection laser beam L1 (long-distance detection light) and the second detection laser beam L2 (short-distance detection light) do not overlap in the vertical field of view, and the emitted light of the laser for short-distance detection and long-distance detection has different energy. According to one preferred embodiment of the invention, the energy of the first detection laser beam L1 for long-distance detection is higher than the energy of the second detection laser beam L2 for short-distance detection.

[0039] 4c, the laser radar 100 includes a first receiving unit 105 and a second receiving unit 106 on the receiving side, the first receiving unit 105 includes a first detector array, and the second receiving unit 106 includes a second detector array, and the first detector array and the second detector array may include various types of photoelectric detectors, such as avalanche photodiodes APD, single photon avalanche diodes SPAD, or silicon photomultiplier tubes SiPM. After being diffusely reflected on the target, the first detecting laser beam L1 and the second detecting laser beam L2 generate a first echo L1' and a second echo L2', respectively, which are returned to the laser radar and focused by the receiving lens 107 on the first receiving unit 105 and the second receiving unit 106, and the first receiving unit 105 and the second receiving unit 106 are configured to receive and convert the first echo L1' and the second echo L2' into electrical signals, respectively, for subsequent circuits to process and analyze the signals. Here, 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 from the receiving lens 107, and the optical path traveled by the first echo L1' is longer than the optical path traveled by the second echo L2', for example.

[0040] The first receiving unit 105 and the second receiving unit 106 may be located at different positions from the receiving lens 107 so 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. For example, the first detector array of the first receiving unit 105 may be located 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 may be smaller than the focal length of the receiving lens 107.

[0041] According to a preferred embodiment of the present invention, as shown in FIG. 4c, the laser radar 100 further includes a receiving end zoom lens 108 at the receiving end, the receiving end zoom lens 108 is disposed 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 through the receiving lens 107 and the receiving end zoom lens 108. As shown in FIG. 4c, after the second echo L2' passes through the receiving end zoom lens 108, a certain change occurs in its direction or divergence, and it is incident on the second detector array. The second detector array of the second receiving unit 106 is located at the focal plane of the lens group consisting of the receiving end zoom lens 108 and the receiving lens 107, and it is preferable that the equivalent focal length of the lens group consisting of the receiving end zoom lens 108 and the receiving lens 107 is smaller than the focal length of the receiving lens 107.

[0042] In addition, those skilled in the art may also consider implementing the receiving end zoom lens 108 by a microlens array MLA, for example, a microlens may be provided 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, FIG. 4a, 4b and 4c are not only a principle diagram of the laser radar 100 according to one embodiment of the present invention, but also a schematic diagram showing the coaxial arrangement of the first receiving unit 105 and the second receiving unit 106 at the receiving side, that is, 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 by different ways. For example, an opening can be opened in the circuit board of the second receiving unit 106 to pass the first echo L1', and an opening can be opened in the center of the zoom lens 108 at the receiving end, so that the first echo L1' is not modulated by the zoom lens 108 at the receiving end. In this case, the first detector array of the first receiving unit 105 can be densely arranged at approximately the middle position of the circuit board. The second detector array of the second receiving unit 106 can be sparsely arranged at approximately the edge position of the circuit board.

[0044] Also or alternatively, the second receiving unit 106 may be divided into upper and lower two parts, which are separated from each other, and the receiving end zoom lens 108 may be divided into two parts, which are separated from each other, and the intermediate space of the second receiving unit 106 and the intermediate space of the receiving end zoom lens 108 may be used to pass the first detection laser beam L1. Also, the above embodiments may be combined, for example, a hole may be drilled in the middle of the circuit board of the second receiving unit 106, and the transmitting end zoom lens 104 may be divided into two parts, or vice versa.

[0045] In addition, those skilled in the art may also consider implementing the receiving end zoom lens 108 by a microlens array MLA, for example, by providing a microlens upstream of the optical path of each detector in the second detector array of the second receiving unit 106, the second echo L2' passing through the receiving lens 107 is modulated by the microlens before being incident on the detector. In addition, other methods may also be implemented, which will be described in detail in the following embodiments.

[0046] The receiving lens 107 may adopt the design of a conventional laser radar for long-distance detection, with a large focal length, and the first detector array of the first receiving unit 105 is directly mounted on the focal plane of the receiving lens 107, which can easily achieve high beamline resolution within a small FOV range. A receiving zoom lens 108 is added near the second receiving unit 106, and the focal length of the lens group consisting of the receiving zoom lens 108 and the receiving lens 107 is small, which is smaller than the focal length of the receiving lens 107, so that a large FOV can be achieved, and at the same time, the height of the light receiving surface of the detector is not high, so that a compact structure can be achieved. According to one preferred embodiment of the present invention, the sensitivity of the first detector array of the first receiving unit 105 for long-distance detection is higher than the sensitivity of the second detector array of the second receiving unit 106 for short-distance detection.

[0047] 4a, 4b and 4c of the present invention is a dual focal length structure laser radar, so the laser radar 100 can achieve both short-distance detection with a large vertical FOV and long-distance detection with a small vertical FOV without significantly increasing the height. Specifically, the transmitting side of the laser radar is provided with two transmitting units for transmitting a first detection laser beam (for long-distance detection) and a second detection laser beam (for short-distance detection), respectively, and the receiving side is provided with two receiving units for receiving echoes generated by the first detection laser beam and the second detection laser beam, i.e., for long-distance detection and short-distance detection, respectively, and the transmitting / receiving pair (for long-distance detection) consisting of one transmitting unit and one receiving unit and the transmitting / receiving pair (for short-distance detection) consisting of another transmitting unit and another receiving unit correspond to different focal lengths, thereby achieving both the long-distance detection performance and the short-distance detection performance of the laser radar with a compact structure.

[0048] FIG. 5 is a plan view schematic diagram of a laser radar 100 according to an embodiment of the present invention, which also has a dual focal length structure. Different from FIG. 4a, 4b and 4c, the first transmitting unit 101 and the second transmitting unit 102 in FIG. 5 are not arranged coaxially, i.e., are not arranged along the optical axis OO of the transmitting lens 103, and the first receiving unit 105 and the second receiving unit 106 are not arranged coaxially, i.e., are not arranged along the optical axis O'O' of the receiving lens 107. As shown in FIG. 5, in addition to the first transmitting unit 101, the second transmitting unit 102, the transmitting lens 103 and the transmitting zoom lens 104 on the transmitting side, the laser radar 100 further includes a transmitting end reflector 109 located between the first transmitting unit 101 and the transmitting lens 103 for receiving the first detection laser beam L1, and 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 transmitted by the second transmitting unit 102 is modulated by the transmitting zoom lens 104 and then emitted through the transmitting lens 103. Preferably, as shown in Fig. 5, the positions of the second transmitting unit 102 and the transmitting zoom lens 104 are set to avoid the propagation path of the first detection laser beam L1, the first detection beam L1 and the second detection laser beam L2 are both emitted toward the center of the lens, and the first detection beam L1 and the second detection laser beam L2 have a small angle difference (the angle difference is 0 in Figs. 4a, 4b and 4c) in the horizontal direction (in Fig. 5, the drawing direction is the horizontal direction, and the direction perpendicular to the drawing is the vertical direction), and compared with the embodiment in Figs. 4a, 4b and 4c, the embodiment in Fig. 5 has a reflector 109, which makes the structure of the laser radar transmission side more compact (its height is smaller).

[0049] Similarly, on the receiving side, the laser radar 100 includes, in addition to the first receiving unit 105, the second receiving unit 106, the receiving lens 107, and the receiving zoom lens 108, a receiving end reflector 110 located between the first receiving unit 105 and the receiving lens 107 for receiving the first echo L1'. The first echo L1' is reflected by the receiving end reflector 110 and then enters the first receiving unit 105. The second echo L2' is entered into the second receiving unit 106 through the receiving lens 107 and the receiving zoom lens 108. Preferably, as shown in FIG. 5, the positions of the second receiving unit 106 and the receiving zoom lens 108 are set to avoid the propagation path of the first echo L1'. By providing the reflector 110, the structure of the laser radar 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] In the embodiment shown in FIG. 5, reflectors are provided on the transmitting side and the receiving side of the laser radar, respectively, but the present invention is not limited to this, and multiple reflectors may be provided, and reflectors may be provided to change the direction of the second detection laser beam L2 and the second echo L2', respectively, which are considered to be within the protection scope of the present invention.

[0051] In the embodiment shown in Figure 5, the long-distance detection light beam emitted from the laser array of the first transmitting unit 101 is reflected once by the transmitting end reflector 109 and folded back, and then emitted through the transmitting lens 103 (main transmitting lens), and the echo of the long-distance detection light beam reflected by an obstacle is received by the receiving lens 107 (main receiving lens), reflected once by the receiving end reflector 110 and folded back, and then detected by the detector array of the first receiving unit 105, and then processed by the subsequent processing unit to obtain distance measurement data. The above detection process corresponds to long-distance detection with a small FOV.

[0052] The short-distance detection beam emitted from the laser array of the second transmitting unit 102 is output by the transmitting lens 103 via the zoom lens 104 at the transmitting end, and the echo reflected by the obstacle of the short-distance detection beam is received by the receiving lens 107, and then detected by the detector array of the second receiving unit 106 via the zoom lens 108 at the receiving end, and then processed by the subsequent processing unit to obtain distance measurement data. The above detection process corresponds to short-distance detection with a large FOV. The readout signals of the detector array of the first receiving unit 105 and the detector array of the second receiving unit 106 can share the signal processing unit.

[0053] Fig. 6 shows a laser radar according to another embodiment of the present invention. The first transmitting unit 101 and the second transmitting unit 102 in Fig. 6 are also not arranged coaxially, i.e., not arranged along the optical axis OO of the transmitting lens 103, and the first receiving unit 105 and the second receiving unit 106 are also not arranged non-coaxially, i.e., not arranged along the optical axis O'O' of the receiving lens 107. Different from the embodiment in Fig. 5, the laser radar in the embodiment in Fig. 6 has multiple reflectors. 6, the transmitting side of the laser radar 100 further includes a first transmitting unit 101, a second transmitting unit 102, a transmitting lens 103, and a transmitting zoom lens 104, as well as a first transmitting end reflector 109 and a second transmitting end reflector 111 which are sequentially positioned between the first transmitting unit 101 and the transmitting lens 103 to reflect a first detection laser beam L1. The first detection laser beam L1 is reflected by the first transmitting end reflector 109 and the second transmitting end reflector 111, respectively, and then emitted through the transmitting lens 103. The second detection laser beam L2 transmitted from the second transmitting unit 102 is modulated by the transmitting zoom lens 104 and then emitted through the transmitting lens 103. Preferably, as shown in FIG. 6, the position of the first transmitting end reflector 109 is set to avoid the propagation path of the second detection laser beam L2, and as shown in FIG. 6, the second transmitting end reflector 111 is provided in the propagation path of the second detection laser beam L2, and a hole may be drilled in the second transmitting end reflector 111 to allow the second detection laser beam L2 to pass through, and another position of the second transmitting end reflector 111 is used to reflect the first detection laser beam L1.

[0054] Similarly, on the receiving side, the laser radar 100 includes a first receiving unit 105, a second receiving unit 106, a receiving lens 107, and a receiving zoom lens 108, as well as a first receiving end reflector 110 and a second receiving end reflector 112, which are located in sequence between the first receiving unit 105 and the receiving lens 107, for reflecting a first echo L1'. The first echo L1' is reflected in sequence by the second receiving end reflector 112 and the first receiving end reflector 110, and then enters the first receiving unit 105. The second echo L2' passes through the receiving lens 107 and the receiving zoom lens 108 and enters the second receiving unit 106. Preferably, as shown in FIG. 6, the position of the first receiving end reflector 110 is set to avoid the propagation path of the second echo L2', and as shown in FIG. 6, the second receiving end reflector 112 is provided in the propagation path of the second echo L2', and a hole may be drilled in the second receiving end reflector 112 to allow the second echo L2' to pass through, and another position of the second receiving end reflector 112 is used to reflect the first echo L1'.

[0055] According to one preferred embodiment of the present invention, as shown in FIG. 7, the laser radar comprises a rotation shaft and an optical rotor rotatable around the rotation shaft, and the optical and electronic components of the transmitting and receiving sides of the laser radar shown in FIG. 4a, FIG. 4b, FIG. 4c, FIG. 5 and FIG. 6 are all integrated in the optical rotor. As shown in FIG. 7a, the optical rotor is provided above the rotation shaft, that is, the rotation shaft of the laser radar does not protrude from the optical rotor. With such a non-through structure, the rotation shaft does not extend to the optical rotor, so that the optical rotor can be provided with more space for providing the optical and electronic components, or the volume of the optical equipment and the volume of the laser radar can be reduced when the components are the same. Of course, the present invention is not limited to the laser radar with a non-through structure, and the rotation shaft of the laser radar may penetrate the optical rotor as shown in FIG. 7b, and the through-shaft structure is more advantageous for rotation stability, which are within the scope of protection of the present invention. Particularly preferably, the laser radar in the embodiment in FIG. 5 has a non-through shaft structure, and the laser radar in the embodiment in FIG. 6 has a through-shaft structure.

[0056] Fig. 8 shows a laser radar 200 according to another embodiment of the present invention. In the embodiment of Fig. 8, the first detection laser beam and the second detection laser beam emitted from the first transmission unit and the second transmission unit of the laser radar are emitted after passing through different transmission lenses, respectively, and accordingly, the first echo and the second echo are received by the first receiving unit and the second receiving unit after passing through different receiving lenses, respectively, and similarly, the transmission / reception pair (for long-distance detection) consisting of the first transmission unit and the first receiving unit and the transmission / reception pair (for short-distance detection) consisting of the second transmission unit and the second receiving unit correspond to different focal lengths, which will be described in detail below with reference to Fig. 8.

[0057] 8, the laser radar 200 includes a first transmitting unit 201 and a second transmitting unit 202 configured to transmit a first detection laser beam L1 and a second detection laser beam L2, respectively, to detect a target, at a transmitting side. The transmitting end optical assembly includes a first transmitting lens 203-1 and a second transmitting lens 203-2 for modulating the first detection laser beam L1 and the second detection laser beam L2, respectively, and outputting them to the outside of the laser radar 200. In addition, the laser radar 200 further includes a first transmitting end reflector 209 and a second transmitting end reflector 211, which are sequentially provided between the first transmitting unit 201 and the first transmitting lens 203-1, at the transmitting side, for sequentially reflecting the first detection laser beam L1. Those skilled in the art can easily understand that the first transmitting end reflector 209 and the second transmitting end reflector 211 are not necessarily required, and the transmitting end reflector may not be provided, or another number of transmitting end reflectors may be provided, as long as the requirements of the optical path and the layout requirements of the mechanical structure are met. In FIG. 8, the second detection laser beam L2 emitted from the second transmitting unit 202 is directly incident on the second transmitting lens 203-2, and is modulated (e.g., collimated) and emitted. One or more reflectors may be provided between the second transmitting unit 202 and the second transmitting lens 203-2, which are within the scope of protection of the present invention. As shown in FIG. 8, the first transmitting lens 203-1 and the second transmitting lens 203-2 are opposed to each other by approximately 180 degrees around the rotation axis of the laser radar (as shown by the black circle in FIG. 8). According to the structure of Fig. 8, the optical path structure for short-distance detection and the optical path structure for long-distance detection are independent from each other, and compared with the structure of the above embodiment, the structure of Fig. 8 is more convenient to install and adjust. In addition, by being opposed at 180 degrees, the design and subsequent signal processing are simplified, and the data of short-distance detection and long-distance detection have an angle difference of 180 degrees in the horizontal direction. The first transmitting unit 201 is disposed, for example, on the focal plane of the first transmitting lens 203-1, and the second transmitting unit 202 is disposed, for example, on the focal plane of the second transmitting lens 203-2.

[0058] As shown in FIG. 8, the laser radar 200 includes a first receiving unit 205 and a second receiving unit 206 configured to receive a first echo L1' and a second echo L2' reflected by a target of the first detection laser beam L1 and the second detection laser beam L2, respectively, at the receiving side and convert them into electrical signals. The receiving end optical assembly includes a first receiving lens 207-1 and a second receiving lens 207-2 for receiving the first echo L1' and the second echo L2', respectively. As shown in FIG. 8, the first receiving lens 207-1 may be provided beside the first transmitting lens 203-1, and the second receiving lens 207-2 may be provided beside the second transmitting lens 203-2. In addition, the laser radar 200 further includes a first receiving end reflector 210 and a second receiving end reflector 212 provided between the first receiving unit 205 and the first receiving lens 207-1 in order to reflect the first echo L1' in order at the receiving side. Those skilled in the art can easily understand that the first receiving end reflector 210 and the second receiving end reflector 212 are not necessarily required, and the receiving end reflector may not be provided, or other numbers of receiving end reflectors may be provided, as long as the requirements of the optical path and the layout requirements of the mechanical structure are met. In FIG. 8, the second echo L2' is directly focused on the second receiving unit 206 through the receiving lens 207-2 and converted into an electrical signal. One or more reflectors may be provided between the second receiving unit 206 and the second receiving lens 207-2, which are within the scope of protection of the present invention. As shown in FIG. 8, the first receiving lens 207-1 and the second receiving lens 207-2 are opposed to each other by approximately 180 degrees around the rotation axis of the laser radar (as shown by the black circle in the center in FIG. 8). The first receiving unit 205 is, for example, provided on the focal plane of the first receiving lens 207-1, and the second receiving unit 206 is, for example, provided on the focal plane of the second receiving lens 207-2. The laser radar 200 shown in FIG. 8 may have a through-shaft structure or a non-through-shaft structure, and is preferably of the non-through-shaft structure.

[0059] As shown in FIG. 8, 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 then reach the first transmitting lens 203-1 and the second transmitting lens 203-2 via different optical paths, and the first echo and the second echo reach the first receiving unit and the second receiving unit via different optical paths from the receiving lens, respectively.

[0060] 8, 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, and is used for long-distance detection with a small FOV in combination with the first transmitting unit 201 and the first receiving unit 205. 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, and is used for short-distance detection with a large FOV in combination with the second transmitting unit 202 and the second receiving unit 206.

[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-transmitting lasers (VCSELs) configured to transmit perpendicularly to the PCB board, and the detectors (arrays) in the first receiving unit 205 and the second receiving unit 206 include, for example, single photon detectors SiPM or SPAD arrays. In addition, the photoelectric device for short-distance detection and the photoelectric device for long-distance detection can share the rotating platform, and perform power supply and signal transmission in a wireless manner. Preferably, in the embodiment shown in FIG. 8, in order to increase the space for accommodating the short-distance detection module and the long-distance detection module of the rotor, the laser radar 200 has a non-through shaft structure (as shown in FIG. 7a), i.e., the rotation shaft of the laser radar does not protrude from the rotor.

[0062] According to one 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, which can reduce the height of the entire lens and make the structure more compact, as shown in Fig. 9. A first field lens 213 located near the focal plane of the first transmitting lens 203-1 may be provided downstream of the optical path of the first transmitting unit 201, and a second field lens 214 located near the focal plane of the first receiving lens 207-1 may be provided upstream of the optical path of the first receiving unit 205. By providing the first field lens 213 and the second field lens 214, the optical path can be pulled back to the optical axis, and at the same time, the first transmitting lens 203-1 and the first receiving lens 207-1 for long-distance detection have a long focal length and a small vertical field of view, and the second transmitting lens 203-2 and the second receiving lens 207-2 for short-distance detection have a short focal length and a large vertical field of view, but the heights of the focal planes of both can be relatively close to each other. Therefore, since there is almost no difference in height between the optical paths for long-range detection and short-range detection, the overall height of the laser radar is very compact and reasonable.

[0063] Also, preferably, the driving circuits of the laser arrays of the first transmitting units 101, 201 and the second transmitting units 102, 202 can be integrated into a chip (multi-channel driving chip), for example, as shown in Fig. 10a, the laser array includes 8 lasers, and the driving circuits of every 4 lasers are integrated into one multi-channel driving chip, so that the laser array corresponds to two multi-channel driving chips, and the lasers and the corresponding multi-channel driving chips are provided on the same PCB board. Preferably, the readout circuits of the detector arrays of the first receiving units 105, 205 and the second receiving units 106, 206 are similarly integrated into a chip (multi-channel analog front-end chip), for example, as shown in Fig. 10b, the detector array includes 32 detectors, and the readout circuits of every 16 detectors are integrated into one multi-channel analog front-end chip, so that the detector array corresponds to two multi-channel analog front-end chips, and the detectors and the multi-channel analog front-end chip are provided on the same PCB board. In this manner, the space occupied by the circuitry in the rotor can be further reduced, which is more convenient for accommodating the short-range detection and long-range detection modules, and the laser radar structure becomes more compact.

[0064] The laser radar of the present invention may further include a data processing unit coupled to the first transmitting unit and the second transmitting unit and the first receiving unit and the second receiving unit, and configured to fuse 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 can achieve both long-distance detection with high resolution and small FOV and short-distance detection with low resolution and large FOV. At the same time, the height of the laser and detector does not increase significantly, and the structure is compact, which is advantageous for installing the laser radar on a vehicle.

[0066] In the laser radar of the embodiment of the present invention, short-distance detection with a large FOV and long-distance detection with a small FOV are integrated at the same time. By adopting a zoom structure, the short-distance detector with a large FOV does not need to have the same focal length as the long-distance detector, and the height of the detector panel is greatly reduced. For the solution of sharing the main lens, the two parts of light beams for short-distance detection and long-distance detection are transmitted from the same set of transmitting and receiving main lenses, so the difference in horizontal angle between short-distance detection and long-distance detection is small, the difference in time for scanning the same object between short-distance detection and long-distance detection is small, and the point clouds from short-distance detection and long-distance detection can be more easily merged.

[0067] The present invention proposes a solution that can achieve both long-distance detection with a small FOV and short-distance detection with a large FOV. A zoom structure is adopted for the short-distance detector with a large FOV, and it does not need to have the same focal length as the long-distance detector. The height of the short-distance detector panel with a large FOV is greatly reduced, so that the height of the laser radar does not need to be increased and the compactness of the entire structure is improved.

[0068] Finally, it should be noted that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention, and the present invention has been described in detail with reference to the above embodiments, but those skilled in the art can still modify the technical solutions described in the above embodiments or replace some of the technical features with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall all be included in the protection scope of the present invention.

Claims

1. A first transmitting unit configured to transmit a first detection laser beam to detect a target at a long distance, and a second transmitting unit configured to transmit a second detection laser beam to detect a target at a short distance; a transmitting end optical assembly including a transmitting lens and a receiving end optical assembly including a receiving lens; a first receiving unit configured to receive a first echo signal reflected by a target from the first detection laser beam and convert the first echo signal into an electrical signal; and a second receiving unit configured to receive a second echo signal reflected by a target from the second detection laser beam and convert the second echo signal into an electrical signal, each of the first and second receiving units includes an avalanche photodiode; the first detection laser beam and the second detection laser beam are emitted from the first transmitting unit and the second transmitting unit, respectively, and then reach the transmitting lens via different optical paths; the first echo and the second echo reach the first receiving unit and the second receiving unit via different optical paths from the receiving lens; 1. A laser radar comprising: a first detection laser beam having a vertical field of view that does not overlap a vertical field of view of the second detection laser beam; and a first detection laser beam having an energy different from an energy of the second detection laser beam.

2. 2. The laser radar according to claim 1, wherein the first transmitting unit and the second transmitting unit are provided at different positions from the transmitting lens, and the first receiving unit and the second receiving unit are provided at different positions from the receiving lens.

3. 3. The laser radar according to claim 1, wherein the first transmitting unit includes a first laser array provided in a focal plane of the transmitting lens, the second transmitting unit includes a second laser array whose distance from the transmitting lens is smaller than a focal length of the transmitting lens, the first receiving unit includes a first detector array provided in a focal plane of the receiving lens, and the second receiving unit includes a second detector array whose distance from the receiving lens is smaller than a focal length of the receiving lens.

4. 4. The laser radar according to claim 3, wherein the second transmitting unit includes a transmitting end zoom lens provided between the second laser array and the transmitting lens, and the second detection laser beam is emitted to the outside of the laser radar through the transmitting end zoom lens and the transmitting lens, and the second receiving unit includes a receiving end zoom lens provided between the second detector array and the receiving lens, and the second echo is incident on the second detector array through the receiving lens and the receiving end zoom lens.

5. 5. The laser radar according to claim 4, further comprising one or more transmitting end reflectors and one or more receiving end reflectors, wherein the first detection laser beam is reflected by the transmitting end reflector and then output through the transmitting lens, and the first echo is reflected by the transmitting end reflector and then input to the first detector array.

6. the transmitting end reflector includes a transmitting end reflector having an aperture, the first detection laser beam is reflected by the transmitting end reflector having the aperture and then emitted through the transmitting lens, and the second detection laser beam passes through the aperture and is emitted through the transmitting lens, 6. The laser radar according to claim 5, wherein the receiving end reflector includes a receiving end reflector having an aperture, the first echo is reflected by the receiving end reflector having the aperture and then incident on the first detector array, and the second echo passes through the aperture and is incident on the second detector array.

7. 3. The laser radar according to claim 1, further comprising: a rotation axis; and an optical rotor rotatable around the rotation axis, the optical rotor including the first and second transmitting units, a transmitting end optical assembly and a receiving end optical assembly, and a first and second receiving unit, the optical rotor being disposed above the rotation axis or the rotation axis passing through the optical rotor.

8. 3. The laser radar according to claim 1, wherein the first and second detection laser beams correspond to different vertical viewing ranges of the laser radar.

9. 3. The laser radar according to claim 1, wherein the energy of the first detection laser beam is higher than that of the second detection laser beam.

10. 3. The laser radar according to claim 1, wherein both the first transmitting unit and the second transmitting unit include a plurality of lasers and a multi-channel driving chip provided on the same PCB board, and both the first receiving unit and the second receiving unit include a plurality of detectors and a multi-channel front-end chip provided on the same PCB board.

11. 3. The laser radar according to claim 1 or 2, further comprising a data processing unit coupled to the first transmitting unit and the second transmitting unit and the first receiving unit and the second receiving unit, and configured to fuse detection results of the first detection laser beam and the second detection laser beam to generate a point cloud.

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