Light detection and ranging LiDAR system and carrier system

Abstract

The utility model relates to a light detection and ranging LiDAR system and a vehicle system. The system comprises: a light source for generating a light signal, the light source comprising a plurality of vertical cavity surface emitting laser (VCSEL) light emitting units; and the detector is used for detecting returned light signals, the detector comprises a plurality of single photon avalanche diode (SPAD) light sensing unit groups, the plurality of VCSEL light emitting units are respectively provided with a light emitting hole, and the area of the light emitting hole is greater than 700 square microns. According to the embodiment of the invention, the extremely sensitive SPAD light sensing unit group is less affected by stray light, halo and crosstalk, the power density of the VCSEL light emitting unit is remarkably improved, and the overall size of the LiDAR system is reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of laser radar detection technology, and in particular to a light detection and ranging LiDAR system and a vehicle system. BACKGROUND

[0002] The light detection and ranging LiDAR system can provide real-time and accurate scene distance information, has the innate advantage of environmental perception, has the advantages of large ranging range and high precision, and is widely used in the field of unmanned driving and the like.

[0003] The core device of the light detection and ranging LiDAR system for emission and reception is a light source and a detector. At present, for various considerations, designing a light detection and ranging LiDAR system that meets the requirements of space compactness, low cost and high performance has become the primary goal of laser radar manufacturers. UTILITY MODEL CONTENT

[0004] According to an aspect of the present disclosure, a light detection and ranging LiDAR system is provided, the system comprising: a light source for generating a light signal, the light source comprising a plurality of vertical cavity surface emitting laser VCSEL light emitting units; and a detector for detecting a returned light signal, the detector comprising a plurality of single photon avalanche diode SPAD light sensing unit groups, wherein the plurality of VCSEL light emitting units each has a light emitting hole, and the area of the light emitting hole is greater than 700 square microns.

[0005] According to another aspect of the present disclosure, a vehicle system is provided, the vehicle system comprising the aforementioned LiDAR system.

[0006] According to some embodiments of the present disclosure, by jointly using the VCSEL light emitting unit as the light source and the SPAD light sensing unit group as the detector, the extremely sensitive SPAD light sensing unit group can be less affected by the adverse effects of stray light, halos and crosstalk, thereby achieving higher detection accuracy when detecting a target. In addition, the VCSEL light emitting unit is arranged to have a large light emitting hole area, which can significantly improve the power density of the VCSEL light emitting unit, thereby allowing effective detection of targets beyond a long distance, and on the other hand, can facilitate reducing the overall size of the LiDAR system, thereby increasing its compactness.

[0007] These and other aspects of the present disclosure will become clear from the embodiments described hereinafter and the drawings attached hereto, and will be illustrated with reference to the embodiments described hereinafter and the drawings attached hereto. BRIEF DESCRIPTION OF DRAWINGS

[0008] In the following description of exemplary embodiments in conjunction with the accompanying drawings, more details, features and advantages of the present disclosure are disclosed, in which:

[0009] Figure 1is a schematic diagram illustrating a light detection and ranging LiDAR system according to some embodiments;

[0010] Figure 2A is a schematic diagram illustrating an arrangement of VCSEL light emitting units in the prior art;

[0011] Figure 2B is a schematic diagram illustrating an arrangement of VCSEL light emitting units according to some embodiments;

[0012] Figure 2C is a schematic diagram illustrating an arrangement of VCSEL light emitting units according to some other embodiments;

[0013] Figure 3A is a schematic diagram illustrating an arrangement of VCSEL chips according to some embodiments;

[0014] Figure 3B is a schematic diagram illustrating an arrangement of SPAD light sensing unit groups corresponding to the arrangement of VCSEL chips in Figure 3A according to some embodiments; and

[0015] Figure 4 is a schematic diagram illustrating a vehicle system according to some embodiments. DETAILED DESCRIPTION

[0016] The present disclosure will be further described in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. In addition, it should be noted that, for the sake of brevity, only portions of the drawings are shown which are necessary to describe the present application.

[0017] In the present disclosure, the terms “first”, “second”, and the like are used to describe various elements only and do not intend to limit the positional relationship, the time sequence relationship, or the importance of the elements, and such terms are only used to distinguish one element from another element. In some examples, the first element and the second element can refer to the same instance of the element, and in some cases, based on the context of the description, they can also refer to different instances.

[0018] The terms used in the description of various described examples in the present disclosure are only for the purpose of describing specific examples and are not intended to be limiting. Unless the context clearly indicates otherwise, if the number of elements is not specifically limited, the element can be one or more. As used herein, the term “plurality” means two or more, and the term “based on” should be interpreted as “based at least in part on”. Furthermore, the terms “and / or” and “at least one of” encompass any and all possible combinations of the listed items.

[0019] At present, for various considerations, designing a light detection and ranging LiDAR system that meets the requirements of compact space, low cost and high performance has become the primary goal of various laser radar manufacturers. The core devices for transmitting and receiving of the light detection and ranging LiDAR system are light sources and detectors. The semiconductor devices that can be used as light sources of the light detection and ranging LiDAR system are semiconductor lasers, which use semiconductor materials as working substances and realize laser output by using semiconductor technology. According to different resonant cavity manufacturing processes, semiconductor lasers are divided into edge emitting lasers (EEL) and vertical cavity surface emitting lasers (VCSEL), etc. Specifically, the laser emission direction of the EEL laser is parallel to the wafer surface, and the resonant cavity is formed by coating optical films on both sides of the chip, and the laser is emitted parallel to the substrate surface. The laser emission direction of the VCSEL laser is perpendicular to the wafer surface, and the resonant cavity is formed by coating optical films on the upper and lower surfaces of the chip, and the laser is emitted perpendicular to the substrate surface. And as a device that can be used as a receiving detector, single photon avalanche diode (SPAD) is rapidly becoming the preferred detector of compact high-performance light detection and ranging LiDAR system.

[0020] In the related art, EEL lasers are usually used together with SPADs in long-distance light detection and ranging LiDAR systems. Although the laser brightness emitted by the EEL laser is high (which is critical for long-distance detection, because the laser power density (i.e. brightness) is high (usually 20,000-30,000 watts per square millimeter), the number of returned signal photons is large), however, due to the extremely sensitive SPAD and the fact that EEL lasers can only emit laser in a sheet, such systems are easily adversely affected by stray light, halos and cross talk.

[0021] In addition, although VCSEL lasers are easy to light up individually, LiDAR systems are relatively less adversely affected by stray light, halos and cross talk. However, the laser power density (i.e. brightness) emitted by the VCSEL laser is low (usually 1,000-2,000 watts per square millimeter), which is not enough to meet the application of long-distance light detection and ranging LiDAR systems. In the related art, in order to obtain sufficient laser power, multiple miniature VCSEL lasers are usually combined together to achieve higher power, however, such combination of multiple miniature VCSEL lasers greatly increases the overall size of the LiDAR system, and the size of the LiDAR system is no longer compact.

[0022] In view of this, the present disclosure uses VCSEL light-emitting units as light sources and SPAD light-sensing unit groups as detectors in combination, so that the extremely sensitive SPAD light-sensing unit groups are less affected by adverse effects of stray light, halos and crosstalk, and higher detection accuracy is achieved when detecting targets. In addition, the VCSEL light-emitting units are arranged to have a large light-emitting hole area, which on the one hand can significantly improve the power density of the VCSEL light-emitting units, thereby allowing effective detection of targets beyond a long distance, and on the other hand can facilitate reduction of the overall size of the LiDAR system, thereby increasing its compactness.

[0023] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0024] Figure 1 is a schematic diagram illustrating a light detection and ranging LiDAR system 100 according to some embodiments. As Figure 1 indicated, the light detection and ranging LiDAR system 100 can include a light source 115 and a detector 125. The light source 115 is configured to generate a light signal to output a laser for scanning a target, e.g. an object, in a field of view (FOV). The light source 115 can be, for example, a semiconductor-based laser. Further reference is made to Figure 3A , Figure 3A is a schematic diagram illustrating an arrangement of a VCSEL chip 300 according to some embodiments. The light source 115 can include a plurality of vertical cavity surface emitting lasers VCSEL light-emitting units. In the example shown in Figure 1 , the plurality of vertical cavity surface emitting lasers VCSEL light-emitting units can be mounted on a VCSEL light-emitting unit board 130. The detector 125 is configured to detect a returned light signal and generate a current and / or voltage signal proportional to the incident intensity of the returned light. Based on such current and / or voltage signal, distance information of a target, e.g. an object, in a field of view (FOV) can be derived. Further reference is made to Figure 3B , Figure 3B is a schematic diagram illustrating an arrangement of a SPAD light-sensing unit group 120 corresponding to the arrangement of the VCSEL chip 300 in Figure 3A . The detector 125 can include a plurality of single photon avalanche diode SPAD light-sensing unit groups 120. In the example shown in Figure 1 , the plurality of single photon avalanche diode SPAD light-sensing unit groups 120 can be mounted on a SPAD light-sensing unit board 140. The SPAD operates in Geiger mode, with a bias voltage higher than the breakdown voltage. Even if only one photon enters, the diode remains in a reverse breakdown state, generating a saturation output current specific to the element, exhibiting infinite gain, and thus having single-photon detection capability.

[0025] In some embodiments, the light detection and ranging LiDAR system 100 may further include an optical scanning device for guiding the light signal generated by the light source 115 to scan the target area 180. In some embodiments, the optical scanning device may include one or more scanning mirrors that can rotate along their respective axes to steer the light signal to scan the environment according to a scanning pattern. For example, the scanning mirror may include one or more rotating mirrors 170 and one or more galvanometer mirrors 175 and 185, the rotating mirror being configured to rotate around its rotation axis so that the light scans the surrounding environment along a first direction, such as a horizontal direction, and the galvanometer mirror being configured to swing around its swing axis so that the light scans the surrounding environment along a second direction, such as a vertical direction. In some embodiments, the rotating mirror 170 may be a mirror having multiple faces, such as a plurality of faces. Figure 1 The optical scanning device can also collect light incident on the target area 180 as a return laser beam. In some embodiments, the light detection and ranging LiDAR system 100 can achieve a horizontal angular resolution of less than 0.1° while providing a horizontal field of view greater than 120°. In some embodiments, based on the desired region of interest (ROI) requirements, the light detection and ranging LiDAR system 100 can adjust the LiDAR horizontal scanning resolution to achieve a horizontal angular resolution of less than 0.05°.

[0026] exist Figure 1 In the example shown, the optical scanning device may further include a galvanometer mirror assembly, namely a first galvanometer mirror 175 and a second galvanometer mirror 185. Figure 1 As shown, the center of the first galvanometer mirror 175 is coated with a high reflective coating 155, which can have a high reflectivity (e.g., greater than about 90-95%). Therefore, in this example, all or substantially all of the incident light beam to the high reflective coating 155 can be reflected to facilitate the formation of the output beam. In addition, as shown in FIG. Figure 1 As shown, both sides of the first galvanometer mirror 175 and the entirety of the second galvanometer mirror 185 can be coated with an anti-reflection coating 165 (e.g., with a reflectivity of less than about 0.5%) to facilitate direct transmission of the light beam through the coating. In some embodiments, the anti-reflection coating includes a graded refractive index (GRIN) anti-reflection coating, an anti-reflection coating based on magnesium fluoride and / or a fluoropolymer, a multilayer interference coating (e.g., alternating layers of a low refractive index material such as silicon dioxide and a higher refractive index material), an absorption coating (e.g., a coating based on titanium nitride and niobium nitride), and the like.

[0027] In some embodiments, the light detection and ranging LiDAR system 100 may further include a transmitting optical device 150 and a receiving optical device 160. The transmitting optical device 150 is configured to receive the light signal generated by the light source 115 and transmit the light signal to an optical scanning device, such as Figure 1As shown, the light is emitted to the galvanometer 175 and the rotating mirror 170. The receiving optical device 160 is configured to collect the returned light signal onto the detector 125. For example, the receiving optical device 160 may include one or more collecting lenses (e.g., a single plano-convex lens or a lens group) to collect the returned light signal and / or focus the collected returned light signal onto the detector 125. In some embodiments, the transmitting optical device 150 and the receiving optical device 160 are arranged horizontally, that is, the transmitting optical device 150 and the receiving optical device 160 are arranged in a horizontal plane or approximately in a horizontal plane, and in association with the transmitting optical device 150 and the receiving optical device 160, the light source 115, the detector 125, and the optical scanning device are arranged or approximately arranged in the same horizontal plane as the transmitting optical device 150 and the receiving optical device 160. By arranging the transmitting optical device 150 and the receiving optical device 160 horizontally, it is possible to reduce the overall size of the LiDAR system, especially the height, thereby increasing its compactness.

[0028] In some embodiments, each of the multiple VCSEL light-emitting units 110 has a light-emitting aperture 200. Compared to VCSEL light-emitting units in related art, the light-emitting aperture 200 is designed to be larger, i.e., to have a large light-emitting aperture area. In some embodiments, the area of ​​the light-emitting aperture 200 is greater than 700 square microns. Preferably, the area of ​​the light-emitting aperture 200 is greater than 700 square microns and less than 2000 square microns. More preferably, the area of ​​the light-emitting aperture 200 is greater than 1250 square microns and less than 2000 square microns. The setting of the area of ​​the light-emitting aperture 200 will be described in detail below and will not be repeated here.

[0029] The light detection and ranging LiDAR system 100 may also include Figure 1 Other components not depicted in the diagram may include a power bus, power supply, LED indicators, switches, etc. Additionally, there may be other communication connections between components, such as a direct connection between the light source 115 and the detector 125 to provide a reference signal so that the time from the transmission of the light signal until the detection of the return light signal can be accurately measured.

[0030] Further references Figures 2A to 2C . Figure 2A FIG2 is a schematic diagram illustrating the arrangement of a VCSEL light emitting unit 110 in the prior art. Figure 2B is a schematic diagram illustrating the arrangement of the VCSEL light emitting unit 110 according to some embodiments, Figure 2C FIG. 1 is a schematic diagram illustrating the arrangement of the VCSEL light emitting unit 110 according to some other embodiments.

[0031] like Figure 2AAs shown, the VCSEL light emitting units 110 in the prior art usually adopt a circular shape, and the optical aperture thereof is generally 10-20 microns. Each VCSEL light emitting unit 110 can usually only generate 1-2 watts of laser power, which is insufficient to meet the application of long-distance light detection and ranging LIDAR system. In order to obtain sufficient laser power, the prior art usually combines multiple VCSEL light emitting units 110 together to generate more than 10 watts of power for each channel. Figure 2A In the example shown, there is a gap d between every two adjacent VCSEL light emitting units 110, and the gap d limits the power density that the VCSEL light emitting units 110 can achieve, because the power density depends on the ratio of the total power generated by the multiple VCSEL light emitting units 110 to the total emission area (including the gap). The typical laser power density (i.e. brightness) emitted by the VCSEL laser is low (usually 1000-2000 watts per square millimeter), which is much lower than the laser power density (i.e. brightness) that the EEL laser can achieve (usually 20000-30000 watts per square millimeter). Therefore, the low power density of the VCSEL laser severely limits the application of the VCSEL and SPAD combined architecture. Therefore, in the prior art, in order to obtain sufficient laser power, multiple VCSEL light emitting units 110 are usually combined together to generate more than 10 watts of power for each channel. As shown, Figure 2A As shown, for each channel, a 2x3 arrangement of VCSEL light emitting units 110 is adopted. In the case where each VCSEL light emitting unit 110 can generate 2 watts of laser power, six VCSEL light emitting units 110 are combined together to generate more than 12 watts of power for the channel. However, simply increasing the VCSEL light emitting units 110 inevitably leads to an increase in the overall size of the LIDAR system, especially the height, thereby adversely affecting its compactness.

[0032] As shown, Figure 2B As shown, according to some embodiments of the present disclosure, the aperture size of the VCSEL light emitting units 110 is adjusted to 40 microns, whereby a higher peak power can be obtained. For example, the aperture of a conventional VCSEL light emitting unit 110 is 20 microns, which can generate a peak power of 2 watts. For a 2x2 arrangement of VCSEL light emitting units (with a gap of 20 microns between every two adjacent VCSEL light emitting units), a peak power of 8 watts can be generated, and the overall area size of the combination is 60 microns x 60 microns, so the overall power density is about 2000 watts per square millimeter. In the case where the aperture of the VCSEL light emitting unit 110 is 40 microns (the aperture size is doubled), a peak power of 8 watts can be generated, and the power density within the aperture is about 6000 watts per square millimeter, which means that the power density is increased by about 3 times. By eliminating the gap d between every two adjacent VCSEL light emitting units 110 in each channel, i.e. arranging the VCSEL light emitting units to have a large light emitting aperture area, the VCSEL power density can be significantly improved.

[0033] In some embodiments, the peak laser power emitted by each of the plurality of VCSEL light emitting units 110 is greater than 4 Watts, such that the power density emitted by each of the plurality of VCSEL light emitting units is greater than 5000 W / mm 2 . At this time, the peak laser power of 4 Watts is sufficient for scanning the target area, while the higher power density (power density exceeding 5000 W / mm 2 ) makes it possible to effectively detect targets at a long distance. Also, at this time, since the VCSEL light emitting units are arranged to have a large light emitting hole area and the gap between every two adjacent VCSEL light emitting units in each channel is eliminated, it is possible to maintain the overall small size of the LiDAR system while allowing effective detection of targets beyond a long distance (200 meters away) without destroying its compactness. In some embodiments, the height of the light detection and ranging LiDAR system 100 is less than 35 millimeters.

[0034] Continuing to refer to Figure 2B , according to some embodiments of the present disclosure, the light emitting hole 200 is circular with a first diameter. In some embodiments, the first diameter is greater than or equal to 30 microns, i.e., the light emitting hole 200 is designed as a large aperture. Preferably, the first diameter is greater than or equal to 30 microns and less than 50 microns. More preferably, the first diameter is greater than or equal to 40 microns and less than 50 microns.

[0035] Further referring to Figure 2C , according to some embodiments of the present disclosure, the light emitting hole 200 is square or rectangular. If the side length of the square is approximately the same as the diameter of the circle, at this time the square is 20% to 30% larger in area than the circle, while the power of the light signal emitted by the VCSEL light emitting unit 110 is basically proportional to the light emitting area. Therefore, compared with the traditional circular VCSEL light emitting unit 110, by arranging the light emitting hole 200 as a square or rectangular shape (rather than a circular aperture), an additional 20 to 30% of power can be increased, and part of the returned light signal in the light signal emitted by the light emitting unit 110 will still fall within the single photon avalanche diode SPAD light sensing unit group 120 which is generally square or rectangular in shape, because the two square or rectangular shapes are matched. Such a design is beneficial to further improve the signal-to-noise ratio and detection distance of the laser radar.

[0036] Although Figure 2B and Figure 2C show the light emitting hole 200 as a circle or a rectangle, it can be understood that the shape of the light emitting hole 200 can not be limited to the shapes shown in Figure 2B and Figure 2C , for example, the shape of the light emitting hole 200 can be a rectangular-like shape with four rounded corners, which is not limited by the present disclosure.

[0037] Further referring to Figures 3A to 3B . Figure 3A is a schematic diagram illustrating an arrangement of the VCSEL chip 300 according to some embodiments, Figure 3B is a schematic diagram illustrating an arrangement of the SPAD photosensing cell group 120 corresponding to the arrangement of the VCSEL chip 300 in Figure 3A .

[0038] As shown in Figure 3B , in order to achieve a vertical angle resolution less than 0.1° in a situation of providing a vertical field of view angle greater than 25°, a sufficient number of SPAD photosensing cell groups 120 are needed to achieve a small vertical angle resolution. For ease of description, the embodiments of the present disclosure will be described below with the second direction Y as the vertical direction as an example, then the first direction X is the horizontal direction, and the first direction X is perpendicular to the second direction Y. In some embodiments, the plurality of SPAD photosensing cell groups 120 includes at least 256 SPAD photosensing cell groups along the second direction Y. At this time, the vertical angle resolution is 25° / 256 = 0.098°, which is less than 0.1°. In Figure 3B the example shown in , the plurality of SPAD photosensing cell groups 120 includes at least 512 SPAD photosensing cell groups along the second direction Y, at this time, the vertical angle resolution is 25° / 512 = 0.048°, which is less than 0.05°. In some embodiments, based on the required region of interest (ROI) requirements, the light detection and ranging LIDAR system 100 can adjust the LIDAR vertical scanning resolution by changing the arrangement of the VCSEL chip 300 and the corresponding arrangement of the SPAD photosensing cell group 120, for example, reducing the spacing between two adjacent SPAD photosensing cell groups 120 along the second direction Y to improve the vertical scanning resolution. According to some embodiments of the present disclosure, each of the plurality of SPAD photosensing cell groups 120 includes nine SPAD photosensing cells 310 arranged in a nine-square form. As shown in Figure 3B , each SPAD photosensing cell group 120 contains 3x3 SPAD photosensing cells 310. SPAD is a binary device due to its single single-photon detector (SPAD), only having two states of “output signal” and “no output signal”, in order to measure the intensity signal of light, so in fact the SPAD array form is used in the light detection and ranging LiDAR system, that is, a plurality of SPAD photosensing cells 310 form a SPAD photosensing cell group 120. Each SPAD photosensing cell 310 outputs as a pixel individually, so as to directly generate an image.

[0039] According to some embodiments of the present disclosure, the plurality of VCSEL light emitting units 110 form a plurality of VCSEL chips 300. In some embodiments, the plurality of VCSEL chips 300 include a first group of VCSEL chips 320 and a second group of VCSEL chips 330 arranged side by side along a first direction X. Figure 3A In the illustrated example, 512 VCSEL light-emitting units 110 form four VCSEL chips 300. Each of the four VCSEL chips 300 includes 128 VCSEL light-emitting units 110. The four VCSEL chips 300 are divided into two groups: a first group of VCSEL chips 320 and a second group of VCSEL chips 330, each group consisting of two VCSEL chips. In some other embodiments, the 512 VCSEL light-emitting units 110 may also form eight VCSEL chips 300. Each of the eight VCSEL chips 300 includes 64 VCSEL light-emitting units 110. The eight VCSEL chips 300 are divided into two groups: a first group of VCSEL chips 320 and a second group of VCSEL chips 330, each group consisting of four VCSEL chips. However, it should be understood that the present disclosure does not limit the grouping of VCSEL chips or the number of VCSEL light-emitting units in each VCSEL chip. In some embodiments of the present disclosure, additional VCSEL chips may be provided to meet redundancy requirements.

[0040] like Figure 3A As shown, the first group of VCSEL chips 320 and the second group of VCSEL chips 330 are staggered along the second direction Y. Specifically, the multiple first VCSEL chips in the first group of VCSEL chips 320 are sequentially arranged and spaced apart from each other along the second direction, and the multiple second VCSEL chips in the second group of VCSEL chips 330 are similarly sequentially arranged and spaced apart from each other along the second direction. Furthermore, each first VCSEL chip in the plurality of first VCSEL chips and the second VCSEL chip adjacent to it along the first direction X are staggered along the second direction Y. The emission fields of view corresponding to adjacent VCSEL chips in the first group of VCSEL chips 320 and the second group of VCSEL chips 330 are spliced ​​along the second direction Y. That is, the emission fields of view of each first VCSEL chip in the plurality of first VCSEL chips and the second VCSEL chip adjacent to it along the first direction X are spliced ​​along the second direction Y. Each VCSEL chip 300 is configured to transmit an optical signal toward a target area. By staggering the multiple VCSEL chips 300 in the vertical direction, the continuity of the vertical field of view can be ensured when the laser radar detects a target area.

[0041] According to some embodiments of the present disclosure, for each of the plurality of first VCSEL chips 320 and the plurality of second VCSEL chips 330, the VCSEL light emitting units thereof are arranged in multiple rows and multiple columns, the VCSEL light emitting units in each column are sequentially arranged and spaced apart from each other along the second direction Y, and each two VCSEL light emitting units in adjacent two columns along the first direction X are staggered arranged along the second direction Y.

[0042] Referring to Figure 3A , each of the plurality of VCSEL chips 300 comprises multiple rows and multiple columns of VCSEL light emitting units 110. The VCSEL light emitting units 110 in each column of each VCSEL chip are sequentially arranged along the second direction Y. As Figure 3A indicated, for each VCSEL chip 300, the multiple columns of VCSEL light emitting units 110 are sequentially arranged along the first direction X, and each two VCSEL light emitting units in adjacent two columns of VCSEL light emitting units 110 along the first direction X are staggered arranged along the second direction Y, so that the emission fields of view of the multiple VCSEL light emitting units 110 in the VCSEL chip 300 are staggered along the vertical direction to uniformly cover the detection field of view. In some embodiments, the staggering distance can be determined according to the size of the VCSEL light emitting units. However, it can be understood that the present disclosure does not limit the arrangement of the VCSEL light emitting units in each VCSEL chip.

[0043] According to another aspect of the present disclosure, a vehicle system is provided, which comprises the LiDAR system of any of the preceding embodiments. The vehicle system includes, but is not limited to, a vehicle, an aircraft, a drone, a ship, etc.

[0044] Figure 4 is a schematic diagram illustrating a vehicle system 400 according to some embodiments. In Figure 4In the example shown, the vehicle system 400 is a vehicle, which can be a vehicle with any level of automation. For example, the vehicle can be a partially automated vehicle, a highly automated vehicle, a fully automated vehicle, or an unmanned vehicle. A partially automated vehicle can perform some driving functions without human driver intervention. For example, a partially automated vehicle can perform blind spot monitoring, lane keeping and / or lane changing, automatic emergency braking, smart cruise control, and / or traffic following, etc. Certain operations of a partially automated vehicle may be limited to specific applications or driving scenarios (for example, limited to highway driving). A highly automated vehicle can perform all operations of a partially automated vehicle, but with fewer restrictions. A highly automated vehicle can also detect its own limits when operating the vehicle and request the driver to take over control of the vehicle when necessary. A fully automated vehicle can perform all vehicle operations without driver intervention, but can also detect its own limits and request the driver to take over when necessary. An unmanned vehicle can operate on its own without any driver intervention.

[0045] LiDAR systems are often essential sensors for at least partially automated vehicles. Figure 4 As shown in , a motor vehicle 100 may include a single LiDAR system 100 disposed below the windshield of the vehicle. Placing the LiDAR system 100 below the windshield of the vehicle facilitates scanning around the vehicle. Due to the small overall size of the LiDAR system in the embodiment, in particular the height, it is not easy to block the driver's field of view while driving. In some other embodiments, the vehicle may include multiple LiDAR systems 100. In some embodiments, multiple LiDAR systems 100 are attached to or integrated into the vehicle at various locations of the vehicle. (Multiple) LiDAR systems 100 are used to scan lasers into the surrounding environment to measure data of the target area, such as the distance, angle and / or speed of an object. Based on the scattered light returned to the (multiple) LiDAR system 100, it can generate data representing the perceived external environment (e.g., image data or 3D point cloud data).

[0046] Some exemplary aspects of the present disclosure are described below.

[0047] Solution 1: A light detection and ranging LiDAR system, comprising:

[0048] A light source, configured to generate an optical signal, the light source comprising a plurality of vertical cavity surface emitting laser (VCSEL) light emitting units; and

[0049] A detector for detecting the returned light signal, wherein the detector comprises a plurality of single photon avalanche diode (SPAD) photosensitive unit groups,

[0050] The plurality of VCSEL light emitting units each have a light emitting aperture with an area greater than 700 square microns.

[0051] In some embodiments, the light emitting aperture is circular with a first diameter greater than or equal to 30 microns.

[0052] In some embodiments, the light emitting aperture is square or rectangular.

[0053] In some embodiments, the plurality of SPAD light sensing unit groups comprises at least 256 SPAD light sensing unit groups, such that a vertical angular resolution of less than 0.1° is achieved while providing a vertical field of view of greater than 25°.

[0054] In some embodiments, each of the plurality of VCSEL light emitting units emits a peak laser power greater than 4 Watts, such that each of the plurality of VCSEL light emitting units emits a power density greater than 5000 W / mm 2 for illuminating the target area more than 200 meters away.

[0055] In some embodiments, the LiDAR system has a height less than 35 millimeters.

[0056] In some embodiments, the light source comprises a plurality of VCSEL chips comprising a first group of VCSEL chips and a second group of VCSEL chips arranged side by side along a first direction, a plurality of first VCSEL chips in the first group of VCSEL chips are arranged sequentially and spaced apart from each other along a second direction, a plurality of second VCSEL chips in the second group of VCSEL chips are each arranged sequentially and spaced apart from each other along the second direction, and each first VCSEL chip in the plurality of first VCSEL chips and a second VCSEL chip adjacent to it along the first direction are arranged staggered along the second direction.

[0057] In some embodiments, the emission field of view of each first VCSEL chip in the plurality of first VCSEL chips and a second VCSEL chip adjacent to it along the first direction are stitched along the second direction.

[0058] Scheme 9, the LiDAR system according to Scheme 7, wherein for each of the plurality of first VCSEL chips and the plurality of second VCSEL chips, the VCSEL light emitting units thereof are arranged in multiple rows and multiple columns, the VCSEL light emitting units in each column are arranged in sequence and spaced apart from each other along the second direction, and each two VCSEL light emitting units in adjacent two columns along the first direction are arranged staggered along the second direction.

[0059] Scheme 10, the LiDAR system according to any one of Schemes 1 to 9, wherein each of the plurality of groups of SPAD light sensing units comprises nine SPAD light sensing units arranged in a nine-square form.

[0060] Scheme 11, the LiDAR system according to any one of Schemes 1 to 10, further comprising:

[0061] an optical scanning device for directing the light signal generated by the light source to scan a target area, and achieving a horizontal angular resolution less than 0.1° in the case of providing a horizontal field of view angle greater than 120°.

[0062] Scheme 12, the LiDAR system according to Scheme 11, further comprising:

[0063] a transmitting optical device configured to receive the light signal generated by the light source and transmit the light signal to the optical scanning device; and

[0064] a receiving optical device configured to collect the returned light signal onto the detector,

[0065] wherein the transmitting optical device and the receiving optical device are horizontally arranged.

[0066] Scheme 13, a vehicle system comprising the LiDAR system according to any one of Schemes 1 to 12.

[0067] Scheme 14, the vehicle system according to Scheme 13, wherein the vehicle system comprises a vehicle, and the LiDAR system is arranged below a windshield of the vehicle.

[0068] While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is to be considered illustrative or exemplary and not restrictive; the disclosure is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, the word "a" or "an" does not exclude a plurality, the term "multiple" means two or more, and the term "based on" means "based at least in part on." The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A light detection and ranging LiDAR system, characterized in that: The system comprises: A light source, configured to generate an optical signal, the light source comprising a plurality of vertical cavity surface emitting laser (VCSEL) light emitting units; and A detector for detecting the returned light signal, wherein the detector comprises a plurality of single photon avalanche diode (SPAD) photosensitive unit groups, Wherein, each of the plurality of VCSEL light-emitting units has a light-emitting hole, and the area of ​​the light-emitting hole is greater than 700 square micrometers.

2. The LiDAR system according to claim 1, wherein: The light-emitting hole is circular with a first diameter, and the first diameter is greater than or equal to 30 micrometers.

3. The LiDAR system according to claim 1, wherein: The light-emitting hole is square or rectangular.

4. The LiDAR system according to any one of claims 1 to 3, characterized in that: The plurality of SPAD photosensitive unit groups include at least 256 SPAD photosensitive unit groups, so that a vertical angle resolution of less than 0.1° is achieved while providing a vertical field angle greater than 25°.

5. The LiDAR system according to any one of claims 1 to 3, characterized in that: The peak laser power emitted by each of the multiple VCSEL light-emitting units is greater than 4 watts, so that the power density emitted by each of the multiple VCSEL light-emitting units is greater than 5000 W / mm 2 , used to illuminate target areas 200 meters away.

6. The LiDAR system according to any one of claims 1 to 3, characterized in that: The system has a height of less than 35 mm.

7. The LiDAR system according to any one of claims 1 to 3, characterized in that: The light source includes a plurality of VCSEL chips composed of the plurality of VCSEL light-emitting units. The plurality of VCSEL chips include a first group of VCSEL chips and a second group of VCSEL chips arranged side by side along a first direction. The plurality of first VCSEL chips in the first group of VCSEL chips are sequentially arranged and spaced from each other along a second direction. The plurality of second VCSEL chips in the second group of VCSEL chips are respectively sequentially arranged and spaced from each other along the second direction. Each first VCSEL chip in the plurality of first VCSEL chips and a second VCSEL chip adjacent to it along the first direction are staggered along the second direction.

8. The LiDAR system according to claim 7, wherein: The emission fields of each first VCSEL chip among the plurality of first VCSEL chips and a second VCSEL chip adjacent to the first VCSEL chip are spliced ​​along the second direction.

9. The LiDAR system according to claim 7, wherein: For each of the plurality of first VCSEL chips and the plurality of second VCSEL chips, its VCSEL light-emitting units are arranged in multiple rows and columns, the VCSEL light-emitting units in each column are sequentially arranged along the second direction and spaced from each other, and every two VCSEL light-emitting units adjacent to each other along the first direction in two adjacent columns are staggered along the second direction.

10. The LiDAR system according to claim 7, wherein: Each of the plurality of SPAD photosensitive cell groups includes nine SPAD photosensitive cells arranged in a nine-square grid.

11. The LiDAR system according to any one of claims 1 to 3, characterized in that: The system further comprises: The optical scanning device is used to guide the optical signal generated by the light source to scan the target area, and to achieve a horizontal angular resolution of less than 0.1° while providing a horizontal field angle greater than 120°.

12. The LiDAR system according to claim 11, wherein: The system further comprises: a transmitting optical device configured to receive an optical signal generated by a light source and transmit the optical signal to the optical scanning device; and a receiving optical device configured to collect the returning optical signal onto the detector, The transmitting optical device and the receiving optical device are arranged horizontally.

13. A carrier system, characterized in that: The vehicle system comprises a LiDAR system according to any one of claims 1 to 12.

14. The carrier system according to claim 13, wherein: The vehicle system includes a vehicle, and the LiDAR system is arranged below a windshield of the vehicle.

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