Solid-state lidar and detection method using same

Abstract

The solid-state laser radar comprises a plurality of transmitting modules, each transmitting module comprises at least one light-emitting unit, and the light-emitting unit comprises a plurality of lasers which are configured to emit detection light beams at the same time; the receiving module comprises at least one detection unit, and the detection unit comprises a plurality of photoelectric detectors and is configured to receive echoes, reflected by a target object, of the detection light beams; wherein the plurality of transmitting modules are arranged around the receiving module, the light-emitting units of the plurality of transmitting modules are located on the same plane, and one detection unit is configured to receive echoes, reflected by a target object, of detection light beams emitted by the light-emitting units of the plurality of transmitting modules. According to the solid-state laser radar, for a field angle in a set range, the lengths of the linear array light-emitting units emitting light simultaneously are greatly reduced by arranging a plurality of emitting modules, so that the light-emitting nonuniformity of the light-emitting units is greatly reduced, the distance measurement error of the solid-state laser radar in the set field angle is reduced, and the distance measurement performance is improved.

Description

[0001] This case is a divisional application of Chinese patent application No. 202110378462.7, filed on April 8, 2021, entitled "Solid-state lidar and method of detection therewith". Technical Field

[0002] This invention relates generally to the field of laser detection technology, and more particularly to a solid-state lidar and a method for detection using the same. Background Technology

[0003] LiDAR (Light Detection and Ranging) can acquire information such as the distance and velocity of targets or achieve target imaging with high precision and accuracy, playing an important role in surveying, navigation, and other fields. LiDAR can generally be divided into two main categories: mechanical LiDAR and solid-state LiDAR. Mechanical LiDAR uses mechanical rotating components to achieve beam scanning, enabling large-angle scanning, but it is difficult to assemble and has a low scanning frequency. Solid-state LiDAR currently utilizes microelectromechanical systems (MEMS), area array solid-state radar, and optical phased array technology.

[0004] The light source of a solid-state lidar array is typically a high-density vertical-cavity surface-emitting laser (VCSEL) array. Multiple lasers are connected in parallel to form a light-emitting unit, which emits light simultaneously under drive. The light-emitting unit is very long and very narrow, with a high aspect ratio. This causes a voltage drop in the resistance and parasitic inductance of the drive circuit under high current and high frequency drive conditions. Consequently, the drive current of the multiple lasers gradually decreases along the propagation direction of the drive signal, and the brightness of the emitted light also gradually decreases. This results in an uneven intensity distribution of the probe light along the extension direction of the light-emitting unit within the lidar's field of view, thus affecting the range finding capability and detection accuracy of the solid-state lidar.

[0005] The content in the background section is merely technology known to the public and does not necessarily represent existing technology in this field. Summary of the Invention

[0006] In view of at least one deficiency of the prior art, the present invention provides a solid-state lidar, comprising:

[0007] Multiple transmitting modules, each of the transmitting modules including at least one light-emitting unit, the light-emitting unit including multiple lasers, configured to simultaneously emit a probe beam;

[0008] The receiving module includes at least one detection unit, the detection unit including multiple photodetectors configured to receive the echo reflected by the detection beam from the target object;

[0009] The plurality of transmitting modules are arranged around the receiving module, the light-emitting units of the plurality of transmitting modules are located on the same plane, and one of the detection units is configured to receive the echo of the detection beam emitted by the light-emitting units of the plurality of transmitting modules being reflected by the target object.

[0010] According to one aspect of the invention, the plurality of lasers of the light-emitting unit are arranged along a strip, and the emitting module includes a plurality of light-emitting units arranged along a direction perpendicular to the extension direction of the strip.

[0011] According to one aspect of the invention, the transmitting modules are disposed on both sides of the receiving module, and the number of transmitting modules on both sides of the receiving module is the same or different.

[0012] According to one aspect of the invention, each of the transmitting modules includes the same number of light-emitting units, and the light-emitting units corresponding to the same detection unit are located on the same straight line.

[0013] According to one aspect of the invention, the field of view portions corresponding to a plurality of light-emitting units located on the same straight line overlap.

[0014] According to one aspect of the invention, the solid-state lidar includes two transmitting modules located on either side of the receiving module.

[0015] According to one aspect of the invention, the light-emitting unit comprises a VCSEL array, and the detection unit comprises a SPAD array.

[0016] According to one aspect of the present invention, a blind spot laser is provided on the side away from the receiving module in the strip-shaped extension direction of the light-emitting unit. The detection range of the blind spot laser and the light-emitting unit are different. The echo of the detection light emitted by the blind spot laser reflected by the target object can be received by the detection unit corresponding to the light-emitting unit.

[0017] According to one aspect of the invention, the emitting module further includes an electrode unit electrically connected to a plurality of lasers of the emitting unit, the electrode unit including a plurality of driving ends, through which driving signals are simultaneously applied to the plurality of lasers of the emitting unit.

[0018] According to one aspect of the invention, the electrode unit further includes pads disposed at both ends of the strip-shaped extension direction of the light-emitting unit, the pads being used to load the driving signal.

[0019] According to one aspect of the invention, the transmitting module further includes a transmitting optical component, at least one light-emitting unit of the transmitting module is located on the focal plane of the transmitting optical component, and the transmitting optical component is configured to receive a probe beam emitted by the at least one light-emitting unit, shape it, and then emit it into the target space.

[0020] According to one aspect of the invention, the emission optical components of the plurality of emission modules are identical.

[0021] According to one aspect of the invention, the emitting module further includes a microlens array disposed downstream of the optical path of the plurality of lasers.

[0022] According to one aspect of the invention, the receiving module further includes:

[0023] The receiving optical component is configured to receive and converge the echo of the detection beam of the first band emitted by the solid-state lidar reflected by the target object and the beam of the second band, wherein the second band does not include the first band.

[0024] A beam splitting unit is disposed downstream of the optical path of the receiving optical component and configured to separate the optical paths of the reflected echo of the probe beam and the beam of the second band.

[0025] The at least one detection unit is disposed downstream of the optical path of the beam splitter and configured to receive the reflected echo of the detection beam from the beam splitter and convert it into an electrical signal; and

[0026] At least one imaging unit is disposed downstream of the optical path of the beam splitter and configured to receive and image the beam of the second band from the beam splitter.

[0027] According to one aspect of the invention, a plurality of photodetectors in each of the detection units are simultaneously activated to receive the reflected echo, each of the imaging units includes a plurality of image sensors, the plurality of image sensors in each of the imaging units are simultaneously activated to receive the beam of the second band and image it, and detection units and imaging units corresponding to the same field of view are simultaneously activated to perform detection and exposure.

[0028] According to one aspect of the invention, the beam splitting unit includes a beam splitting mirror that reflects the reflected echo of the probe beam and transmits the beam of the second band, or transmits the reflected echo of the probe beam and reflects the beam of the second band.

[0029] The present invention also provides a method for detection using the solid-state lidar as described above, comprising:

[0030] The light-emitting unit of the emission module emits a detection beam to detect the target object;

[0031] The detection unit of the receiving module receives the echo reflected by the target object from the detection beam;

[0032] The distance to the target is determined based on the time of emitting the probe beam and the time of receiving the echo.

[0033] According to one aspect of the present invention, the solid-state lidar includes two transmitting modules located on either side of the receiving module, the two transmitting modules including an equal number of light-emitting units, and the light-emitting units corresponding to the same detection unit being located on the same straight line, the method further comprising:

[0034] Two light-emitting units corresponding to the same detection unit emit light simultaneously or alternately.

[0035] According to one aspect of the present invention, a plurality of lasers of the light-emitting unit are arranged in a strip, and a blind spot laser is provided on the side away from the receiving module in the strip extension direction of the light-emitting unit. The detection range of the blind spot laser and the light-emitting unit are different. The echo of the detection light emitted by the blind spot laser being reflected by the target object can be received by the detection unit corresponding to the light-emitting unit. The method further includes: the blind spot laser and the light-emitting unit emit light simultaneously.

[0036] According to one aspect of the present invention, wherein the plurality of lasers of the light-emitting unit are arranged in a strip, the emitting module further includes an electrode unit electrically connected to the plurality of lasers of the light-emitting unit, the electrode unit including a plurality of driving ends, and the method further includes:

[0037] The multiple driving terminals simultaneously apply driving signals to multiple lasers of the light-emitting unit.

[0038] According to one aspect of the invention, the electrode unit further includes pads disposed at both ends of the strip-shaped extension direction of the light-emitting unit, and the method further includes:

[0039] The drive signal is loaded through the pad.

[0040] According to one aspect of the present invention, the receiving module further includes: a receiving optical component; a beam splitting unit disposed downstream of the optical path of the receiving optical component; the at least one detection unit disposed downstream of the optical path of the beam splitting unit; and at least one imaging unit disposed downstream of the optical path of the beam splitting unit. The method further includes:

[0041] The receiving optical component receives and converges the echo of the first band detection beam emitted by the solid-state lidar reflected by the target object and the second band beam, wherein the second band does not include the first band.

[0042] The optical paths of the reflected echo of the probe beam and the beam of the second band are separated by the beam splitting unit.

[0043] The at least one detection unit receives the reflected echo of the detection beam from the beam splitter and converts it into an electrical signal.

[0044] The beam of the second band is received from the beam splitter and imaged by the at least one imaging unit.

[0045] A preferred embodiment of the present invention provides a solid-state lidar. For a set field of view, by setting multiple emission modules, the length of the linear light-emitting units that emit light simultaneously is greatly reduced, thereby greatly reducing the light emission non-uniformity of the light-emitting units, thereby reducing the ranging error of the solid-state lidar within the set field of view and improving the range measurement performance.

[0046] In a preferred embodiment of the present invention, the number of lasers emitting light simultaneously is reduced, thereby lowering the emission power of a single light-emitting unit, reducing heat dissipation at the emitting end, and reducing temperature fluctuations.

[0047] In a preferred embodiment of the present invention, when multiple emitting modules correspond to different light-emitting units that do not emit light simultaneously, the emission power of a single emission can be reduced, which is beneficial to human eye safety. While meeting human eye safety requirements, the reduced number of simultaneously emitting lasers allows for increased laser power, improved detection light power, and enhanced ranging capability of the lidar.

[0048] In a preferred embodiment of the present invention, after the detection light emitted by multiple transmitting modules is shaped and emitted, there is a certain overlap area in the field of view at the center, which can increase the detection accuracy of the center area.

[0049] In a preferred embodiment of the present invention, the length of the linear light-emitting units in some of the transmitting modules can be appropriately extended, thereby effectively reducing the blind zone of the solid-state lidar, eliminating the need for special design of the laser array, and not increasing the complexity of design and manufacturing. Attached Figure Description

[0050] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0051] Figure 1 A schematic illustration of a solid-state lidar in the prior art;

[0052] Figure 2 A schematic diagram of a portion of the surface structure of a top-emitting vertical-cavity surface-emitting laser (VCSEL) array light source is shown.

[0053] Figure 3 The diagram illustrates a case of uneven emission from a series of parallel lasers.

[0054] Figure 4A A side view of a solid-state lidar according to a preferred embodiment of the present invention is shown schematically;

[0055] Figure 4B A schematic front view of a solid-state lidar according to a preferred embodiment of the present invention is shown;

[0056] Figure 5A A side view of a solid-state lidar according to a preferred embodiment of the present invention is shown schematically;

[0057] Figure 5B A schematic front view of a solid-state lidar according to a preferred embodiment of the present invention is shown;

[0058] Figure 6A A solid-state lidar that scans line by line in the vertical direction according to a preferred embodiment of the present invention is illustrated schematically.

[0059] Figure 6B A solid-state lidar that scans column by column in the horizontal direction according to a preferred embodiment of the present invention is illustrated schematically.

[0060] Figure 7 The field of view of a solid-state lidar according to a preferred embodiment of the present invention is schematically shown;

[0061] Figure 8 The formation of the blind zone in a bypass lidar is illustrated schematically.

[0062] Figure 9 A schematic diagram of the optical path of a blind spot filler laser according to a preferred embodiment of the present invention is shown.

[0063] Figure 10 The position of the blind spot laser on the linear light-emitting unit is schematically shown according to a preferred embodiment of the present invention;

[0064] Figure 11 The illustration schematically shows a bidirectional drive provided for the linear light-emitting unit according to a preferred embodiment of the present invention;

[0065] Figure 12 The illustration schematically shows the integration of a laser array with a microlens array according to a preferred embodiment of the present invention;

[0066] Figure 13 A receiving module according to a preferred embodiment of the present invention is illustrated schematically;

[0067] Figure 14 A receiving module according to a preferred embodiment of the present invention is illustrated schematically;

[0068] Figure 15 A solid-state lidar according to a preferred embodiment of the present invention is illustrated schematically;

[0069] Figure 16 A detection method according to a preferred embodiment of the present invention is shown. Detailed Implementation

[0070] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0071] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0073] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0074] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0075] The embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0076] The transceiver structure and working principle of area array solid-state lidar are as follows: Figure 1 As shown, the transmitting module TX includes a laser array, and the receiving module RX includes a detector array. The laser array and the detector array are respectively positioned on the focal planes of the transmitting lens group and the receiving lens group (not shown in the figure). The laser array emits a detection beam to detect the target object (OB). The echo beam reflected by the target object is received by the detector array, which converts the optical signal into an electrical signal. After time conversion and histogram processing, the distance information is finally obtained and sent to the monitoring system to form a point cloud image.

[0077] As one of the detection methods of area array solid-state lidar, the laser array of the transmitting module is simultaneously driven to emit detection light covering the detection range, and the detector array of the receiving module is activated to receive the echo signal.

[0078] As one of the detection methods of area array solid-state lidar, the laser array of the transmitting module and the detector array of the receiving module can be grouped and emitted / detected sequentially. For example... Figure 1As shown, each column of lasers is activated simultaneously as a single emitting unit, and each column of detectors is activated simultaneously as a single detecting unit. At time t1, the first column of lasers emits light, and the corresponding first column of detectors is activated to detect the echo signal; at time t2, the second column of lasers emits light, and the corresponding second column of detectors is activated to detect the echo signal, and so on. This reduces crosstalk caused by all lasers emitting light and detecting simultaneously. Alternatively, lasers can be grouped by row, by subarray, etc., with each group of lasers emitting light simultaneously and the corresponding group of detectors activating simultaneously to detect the echo signal. The grouping method is not limited to the methods described above.

[0079] Larger-scale solid-state lidar uses a high-density laser array as its light source. This array can take full advantage of the fact that vertical cavity surface-emitting lasers are easier to integrate on a large scale compared to edge-emitting lasers, thereby increasing power density while reducing packaging, assembly complexity and cost.

[0080] In one implementation, the laser is a vertical-cavity surface-emitting laser (VCSEL), and the detector is a single-photon avalanche diode (SPAD).

[0081] Figure 2 A schematic diagram of a partial surface structure of a top-emitting vertical-cavity surface-emitting laser (VCSEL) array light source is shown. Figure 2 The VCSELs in the structure are arranged in a matrix and designed as a column-addressable structure. That is, each column of VCSELs serves as... Figure 1 One of the light-emitting units in the TX emission module, the anode contact metals of each column of VCSELs are interconnected through interconnect metal layers, and the ends of the interconnect metal layers serve as bonding pads for wire bonding (e.g. Figure 2 (As indicated in the diagram), connected to the driver chip via metal wire bonding, VCSELs in the same column are excited by the same driving signal (from the driving circuit on the driver chip). To increase the current conduction area and reduce resistance, the pad area is relatively large, approximately twice the width of the light-emitting unit. The pads of adjacent columns are located at the lower edge of the array (not shown in the figure), and... Figure 2 The upper edge structure shown is symmetrical.

[0082] like Figure 2The vertical-cavity surface-emitting laser (VCSEL) array shown achieves the high-density integration required for a large emitting area. However, this results in a problem: each row of parallel-emitting lasers (i.e., a single emitting unit) is very long and narrow, with a high aspect ratio. This leads to voltage drops due to the resistance and parasitic inductance on the metal layer under high-current, high-frequency driving conditions. Consequently, the bias voltage of the same row of lasers gradually decreases, resulting in a gradual decrease in luminous intensity. Figure 3 As shown, pixel-1 is the laser closest to the pad, and pixel-21 is the laser furthest from the pad. Due to the voltage drop caused by the resistance and parasitic inductance on the metal layer, the brightness of each laser is different, and the brightness of pixel-21 is significantly lower than that of pixel-1.

[0083] In the application of area array solid-state lidar, the different luminous intensities of multiple lasers in a single luminous unit will result in different ranging capabilities within the corresponding field of view of that luminous unit. Among them, the lasers with lower luminous intensities limit the range measurement capability of the lidar, causing point cloud image distortion and reducing the detection accuracy of the lidar.

[0084] To address the issue of uneven light emission intensity in linear light-emitting units of area-array solid-state lidar, such as... Figure 4A As shown, the present invention provides a solid-state lidar 100, including multiple transmitting modules 110 and receiving modules 120. For example... Figure 4B As shown ( Figure 4A This is a side view of a solid-state lidar 100. Figure 4B (This is a front view tilted at a certain angle), wherein each transmitting module 110 includes at least one light-emitting unit 111, the light-emitting unit 111 including multiple lasers configured to simultaneously emit a detection beam. The receiving module 120 includes at least one detection unit 121, the detection unit 121 including multiple photodetectors configured to receive the echo of the detection beam reflected by the target object.

[0085] like Figure 4A As shown, multiple transmitting modules 110 are arranged around the receiving module 120, and the light-emitting units 111 of the multiple transmitting modules 110 are located on the same plane. A detection unit 121 is configured to receive the echo of the detection beam emitted by the light-emitting units 111 of the multiple transmitting modules 110 being reflected by the target object. Figure 4B As shown, preferably, one detection unit 121 corresponds to one light-emitting unit 111 in each transmitting module 110, and the detection unit 121 is configured to receive the reflected echo of the detection beam emitted by the corresponding plurality of light-emitting units 111.

[0086] According to a preferred embodiment of the present invention, the solid-state lidar 100 includes a VCSEL linear array in its light-emitting unit 111 and a SPAD linear array in its detection unit 121. For example... Figure 4A , Figure 4B As shown, two VCSEL arrays are symmetrically arranged on both sides of the SPAD array. Each row of VCSELs is simultaneously activated as a single emitting unit, and each row of SPADs is divided into two parts according to the placement of the two emitting modules 110, as shown below. Figure 4B As shown, the half of the SPAD, represented by the diagonal shading, serves as a detector sub-unit, corresponding to the same field of view as the light-emitting unit (represented by the diagonal shading in the transmitter module 110 on the left side of the figure). It receives the echo of the detector light emitted by one of the light-emitting units of the transmitter module 110 on the left side of the figure, which is reflected by the target object. The other half of the SPAD in the row represented by the square shading serves as another detector sub-unit, corresponding to the same field of view as the light-emitting unit (represented by the square shading in the transmitter module 110 on the right side of the figure). It receives the echo of the detector light emitted by one of the light-emitting units of the transmitter module 110 on the right side of the figure, which is reflected by the target object.

[0087] The detection method of the solid-state lidar 100 of the present invention can be as follows: the two transmitting modules 110 are equivalent to light-emitting units in the same row emitting light sequentially, and the corresponding detection sub-units of the receiving module 120 perform detection respectively. Alternatively, the two transmitting modules 110 are equivalent to light-emitting units in the same row emitting light simultaneously, and the detectors in the corresponding row of the receiving module 120 in the field of view are activated to simultaneously receive and detect the reflected echoes from the two light-emitting units.

[0088] According to a preferred embodiment of the present invention, in the solid-state lidar 100, the transmitting module 110 further includes a transmitting optical component. At least one light-emitting unit 111 of the transmitting module 110 is located on the focal plane of the transmitting optical component. The transmitting optical component is configured to receive the detection beam emitted by at least one light-emitting unit 111, shape it, and then transmit it to the target space.

[0089] According to a preferred embodiment of the present invention, in the solid-state lidar 100, the transmitting module 110 further includes a transmitting lens group corresponding to the laser array; the receiving module 120 further includes a receiving lens group corresponding to the detector array.

[0090] According to a preferred embodiment of the present invention, such as Figure 4B As shown, in the solid-state lidar 100, multiple lasers of the light-emitting unit 111 are arranged in a strip (e.g., Figure 4B (as shown in the x-direction), the emitting module 110 includes a plurality of light-emitting units 111, which are arranged along a direction perpendicular to the strip's extension direction (e.g., the x-direction shown in the figure). Figure 4B y direction shown in ).

[0091] See Figure 4B As indicated in the diagram, in both emitting modules 110, the multiple lasers of the light-emitting unit 111 are arranged along the x-direction, and the multiple light-emitting units 111 are arranged along the y-direction (the diagram shows an oblique view; in reality, the x-direction and y-direction are perpendicular). Preferably, the length of the laser array in the y-direction is greater than its length in the x-direction.

[0092] Back Figure 1 The solid-state lidar shown contains only one transmitting module. Assuming the laser array of the transmitting module is an N×N array, after improving the solid-state lidar using the preferred embodiment provided by this invention, as follows... Figure 4B As shown, the solid-state lidar 100 includes two transmitting modules 110. The laser arrays of the two transmitting modules 110 are N×½N arrays, and a row / column of lasers extending along the ½N direction serves as a light-emitting unit, emitting light simultaneously.

[0093] For the same detection range, Figure 4B In the embodiment, the length of the light-emitting unit 111 of the emitting module 110 is only Figure 1 The length of the light-emitting unit in a single-lens solid-state lidar is half that of the laser, which can shorten the transmission path length of the laser driving signal, reduce the difference in the intensity of the laser driving signal at both ends of the transmission path, and effectively reduce the non-uniformity of the laser luminous intensity at different positions in the light-emitting unit.

[0094] Figure 4A , Figure 4B The diagram schematically shows that the length of the light-emitting unit 111 of the emitting module 110 is half the length of the original light-emitting unit before the improvement. This division method is only a preferred embodiment. The lengths of the light-emitting units 111 of multiple emitting modules 110 can be equal or unequal. For example, the length ratio of the light-emitting units 111 of two emitting modules 110 can be 4:6, 4.5:5.5, or other ratios. These are also within the protection scope of this invention.

[0095] According to a preferred embodiment of the present invention, the transmitting modules 110 are disposed on both sides of the receiving module 120, and the number of transmitting modules 110 on both sides of the receiving module 120 may be the same or different. To solve the problem of uneven light emission intensity of linear light-emitting units in solid-state lidar, the preferred embodiment provided by the present invention divides the laser array in the transmitting module into multiple parts along the laser arrangement direction. This is readily understood by those skilled in the art. Furthermore, the laser array is further divided along the arrangement direction of the multiple light-emitting units, thereby reducing the area of ​​the laser chip, reducing heat dissipation, and improving yield. This implementation method is also feasible and falls within the protection scope of the present invention.

[0096] Figure 4A , Figure 4BThe embodiment illustrates a case where the solid-state lidar 100 includes two transmitting modules 110, such as Figure 5A As shown, the transmitting module 110 is further divided, making the length of each row of parallel-emitting lasers (one emitting unit) shorter, and multiple transmitting modules 110 are arranged around the receiving module 120, with the emitting units 111 of the multiple transmitting modules 110 located on the same plane. Figure 5B As shown, each transmitting module 110 includes at least one light-emitting unit 111, which includes multiple lasers configured to simultaneously emit a detection beam; the receiving module 120 includes at least one detection unit 121, which includes multiple photodetectors configured to receive the echo of the detection beam reflected by the target object. Preferably, one detection unit 121 corresponds to one light-emitting unit 111 in each transmitting module 110, and the detection unit 121 is configured to receive the reflected echo of the detection beam emitted by the corresponding multiple light-emitting units 111. That is, the technical solution of the solid-state lidar 100 including a larger number of transmitting modules 110 is also within the protection scope of this invention.

[0097] like Figure 5A , Figure 5B In the embodiments shown, each transmitting module 110 corresponds to a transmitting optical component; or, two or more adjacent transmitting modules 110 located on one side of the receiving module 120 may share a transmitting optical component.

[0098] According to a preferred embodiment of the present invention, in the solid-state lidar 100, each emitting module 110 includes a plurality of light-emitting units 111 of the same number, and the light-emitting units 111 corresponding to the same detection unit 121 are located on the same straight line.

[0099] like Figure 6A As shown, according to a preferred embodiment of the present invention, the solid-state lidar 100 includes two transmitting modules 110 and one receiving module 120. Each transmitting module 110 includes a plurality of light-emitting units 111 of the same number, and each receiving module 120 includes a plurality of detection units 121. Each detection unit 121 corresponds to one light-emitting unit 111 in each transmitting module 110. The two transmitting modules 110 and the receiving module 120 of the solid-state lidar 100 are arranged in a horizontal direction (the horizontal direction shown in the figure), and the solid-state lidar 100 performs line-by-line scanning in a vertical direction (the vertical direction shown in the figure). Therefore, the light-emitting units 111 corresponding to the same detection unit 121 are located on the same horizontal line (the horizontal direction shown in the figure), and the light-emitting units 111 corresponding to the same detection unit 121 correspond to the same vertical field of view.

[0100] like Figure 6BAs shown, according to a preferred embodiment of the present invention, the solid-state lidar 100 includes two transmitting modules 110 and one receiving module 120. Each transmitting module 110 includes a plurality of light-emitting units 111, and each receiving module 120 includes a plurality of detection units 121. Each detection unit 121 corresponds to one light-emitting unit 111 in each transmitting module 110. The two transmitting modules 110 and the receiving module 120 of the solid-state lidar 100 are arranged vertically (vertical direction shown in the figure), and the solid-state lidar 100 performs column-by-column scanning along a horizontal direction (horizontal direction shown in the figure). Therefore, the light-emitting units 111 corresponding to the same detection unit 121 are located on the same vertical line (vertical direction shown in the figure). Furthermore, the light-emitting units 111 corresponding to the same detection unit 121 correspond to the same horizontal field of view.

[0101] According to a preferred embodiment of the present invention, the light-receiving path of the solid-state lidar 100 is as follows: Figure 7 As shown. In this configuration, the laser emitted from the side of the transmitting module 110-1 closest to the receiving module 120 is shaped by the transmitting lens group and emitted parallel to the optical axis. As the laser moves away from the receiving module 120, the emitted beam is sequentially deflected towards the receiving module 120, forming... Figure 7 The field of view (FOV) 1 is shown in the diagram. Similarly, the light emitted by the laser on the side of the transmitting module 110-2 closest to the receiving module 120 is shaped by the transmitting lens group and emitted parallel to the optical axis. As the laser moves away from the receiving module 120, the emitted beam is successively deflected towards the receiving module 120, forming... Figure 7 The field of view FOV2 is shown in the figure.

[0102] It can be seen that the field of view of the transmitting module 110-1 and the transmitting module 110-2 overlap to a certain extent. Figure 7 As shown in the solid area on the middle ob), when the light-emitting units corresponding to the transmitting modules 110-1 and 110-2 emit light simultaneously, the light intensity of the overlapping area is doubled, which can improve the distance measurement capability of the area; when the light-emitting units corresponding to the transmitting modules 110-1 and 110-2 do not emit light simultaneously, the detection frequency of the area is doubled within a certain period of time.

[0103] If the transmitting module 110-1, receiving module 120, and transmitting module 110-2 are arranged vertically, the field of view of transmitting module 110-1 and transmitting module 110-2 overlaps to a certain extent in the vertical direction. This overlapping area is located at the center of the vertical field of view of the lidar. Vehicle-mounted lidar primarily detects pedestrians and vehicles on the ground, with targets concentrated at the center of the vertical field of view. The above embodiment can improve the distance measurement capability or detection frequency in the central area, making it more suitable for vehicle-mounted lidar application scenarios.

[0104] If the transmitting module 110-1, the receiving module 120, and the transmitting module 110-2 are arranged in a horizontal direction, the field of view of the transmitting module 110-1 and the transmitting module 110-2 overlap in a certain way in the horizontal direction. The overlapping area is located at the center of the horizontal field of view of the lidar, that is, directly in front of the lidar. The above embodiment can improve the distance measurement capability or detection frequency of the lidar in the forward area.

[0105] A preferred embodiment of the present invention provides a solid-state lidar. For a set field of view, by setting multiple emission modules, the length of the linear light-emitting units that emit light simultaneously is greatly reduced, thereby greatly reducing the light emission non-uniformity of the light-emitting units, thereby reducing the ranging error of the solid-state lidar within the set field of view and improving the range measurement performance.

[0106] In a preferred embodiment of the present invention, the number of lasers emitting light simultaneously is reduced, thereby lowering the emission power of a single light-emitting unit, reducing heat dissipation at the emitting end, and reducing temperature fluctuations.

[0107] In a preferred embodiment of the present invention, when the light-emitting units corresponding to multiple emitting modules do not emit light simultaneously, the emission power of a single emission can be reduced, which is beneficial to human eye safety. While meeting human eye safety requirements, the reduced number of simultaneously emitting lasers allows for increased laser power, improved detection light power, and enhanced ranging capability of the lidar. Furthermore, the corresponding number of detectors performing simultaneous detection is reduced, thus lowering signal crosstalk between multiple detectors.

[0108] In a preferred embodiment of the present invention, after the detection light emitted by multiple transmitting modules is shaped and emitted, there is a certain overlap area in the field of view at the center, which can increase the detection accuracy of the center area.

[0109] In a preferred embodiment of the present invention, the length of the linear light-emitting units in some of the transmitting modules can be appropriately extended, thereby effectively reducing the blind zone of the solid-state lidar, eliminating the need for special design of the laser array, and not increasing the complexity of design and manufacturing.

[0110] According to a preferred embodiment of the present invention, in the solid-state lidar 100, a blind spot laser is provided on the side away from the receiving module 120 in the strip-shaped extension direction of the light-emitting unit 111. The detection range of the blind spot laser is different from that of the light-emitting unit 111, and the echo of the detection light emitted by the blind spot laser being reflected by the target object can be received by the detection unit 121 corresponding to the light-emitting unit 111.

[0111] Off-axis lidar suffers from near-far effect, meaning that the spot of the echo beam on the photosensitive surface shifts as the distance to the target changes. For example... Figure 8As shown, when the distance to the target object decreases to a critical distance, the light spot will move out of the photosensitive surface of the array detector and become undetectable by the radar. Figure 8 The area where the light rays from the transmitting module TX and the receiving module RX do not overlap is the blind zone of the lidar. For a target within this blind zone, the image point formed by the reflected echo light through the receiving lens is not on the focal plane of the receiving lens (the location of the area array detector of the receiving module RX in the diagram), but behind the focal plane. Furthermore, in Figure 8 From the perspective of [the target], the near-range target is below the optical axis of the receiving lens, so the image point formed by the receiving lens must be above the optical axis of the receiving lens. Considering both aspects, the relative position of the focal point of the reflected light from the near-range target and the receiving module RX is as follows: Figure 8 As shown in the diagram. Within the near-range blind zone of the lidar, the lidar's receiver module RX cannot receive the target's reflected signal at all.

[0112] This invention provides a solution for reducing blind spots, such as... Figure 9 As shown, the transmitting module TX is equipped with a blind spot laser, located on the side of the transmitting module TX furthest from the receiving module RX. The probe light, after passing through the transmitting lens, is deflected into the blind spot area for supplementary measurement. The transmitting module TX is positioned on the focal plane of the transmitting optical assembly. Because multiple lasers are located at different positions on the focal plane, their emitted light is deflected in different directions after collimation by the transmitting optical assembly. (As described above...) Figure 7 In the solid-state lidar 100 shown, a blind spot laser is also installed on the side of the transmitting module TX2 away from the receiving module RX, and the optical path is as follows: Figure 7 The image shows the detection beam emitted by the edge-filling laser.

[0113] like Figure 10 As shown, the blind spot laser is positioned on the side of the light-emitting unit furthest from the optical axis of the emitting optics along the strip arrangement direction. The emitted beam, after being shaped and collimated by the emitting optics, has the largest angle between its exit angle and the optical axis, forming the blind spot detection beam. For far-field echoes, the echo beam spot of the blind spot laser will be focused outside the array detector and cannot be detected; however, as the distance to the target decreases, the echo beam spot exhibits... Figure 9 As shown, the laser shifts upwards and lands on the detector at the RX direction. At this time, the echo of the nearby target of the blind spot laser can be received by the detector because it is shifted upwards, thereby reducing the blind zone range of the lidar.

[0114] As another preferred option, Figure 7 A blind spot laser can also be set on the side of the transmitting module TX1 that is far from the receiving module RX to further reduce the blind spot range.

[0115] Combined with appendix Figure 7 , Figure 8, 9 and Figure 10 A blind spot filler laser is essentially an extension of the linear light-emitting unit along its extension direction, i.e., an increase in the number of lasers, without changing the laser arrangement. This method is simple and low-cost. The number of lasers required to reduce the blind spot can be calculated based on the optical path according to the optical design.

[0116] According to a preferred embodiment of the present invention, in the solid-state lidar 100, the transmitting module 110 further includes an electrode unit, which is electrically connected to a plurality of lasers of the light-emitting unit 111. The electrode unit includes a plurality of driving ends, through which driving signals are simultaneously applied to the plurality of lasers of the light-emitting unit 111.

[0117] Preferably, the electrode unit further includes pads disposed at both ends of the strip-shaped extension direction of the light-emitting unit 111, the pads being used to load the driving signal.

[0118] To further reduce the light emission non-uniformity of the linear light-emitting unit, this invention employs dual-sided driving for the linear light-emitting unit. Unlike... Figure 2 As shown in the prior art, a driving signal is passed to one side pad of the linear light-emitting unit, such as... Figure 11 As shown, according to a preferred embodiment of the present invention, pads are respectively provided on both sides of the strip-shaped extension direction of the linear light-emitting unit, and driving circuits are respectively connected to them. Two driving circuits connected to the same light-emitting unit are controlled by the same emission control signal, and simultaneously turn on the driving switch. Driving signals are simultaneously injected from both ends of the same light-emitting unit, such as... Figure 11 As described above, driving circuit 1 and driving circuit 2 each generate a driving signal component acting on the same laser. The two driving signal components are superimposed to form a driving signal that controls the laser's emission. Thus, one driving signal component can compensate for the attenuation caused by the driving circuit of the other driving signal component, making the difference in driving current flowing through the multiple lasers on the driving circuit smaller, and further reducing the non-uniformity of emission.

[0119] According to a preferred embodiment of the present invention, in the solid-state lidar 100, the transmitting module 110 further includes a microlens array disposed downstream of the optical path of multiple lasers.

[0120] Laser arrays can be used in conjunction with microlens arrays, such as... Figure 12 As shown, a microlens array is fixed in front of the laser array, or the substrate of the laser chip is fabricated into a microlens array to collimate the beam emitted by the laser and improve the beam quality.

[0121] According to a preferred embodiment of the present invention, such as Figure 13As shown, in the solid-state lidar 100, the receiving module 120 further includes: a receiving optical component 122, a beam splitting unit 123, at least one detection unit 121, and at least one imaging unit 124. Wherein:

[0122] The receiving optical component 122 is configured to receive and converge the echo L1 reflected by the target object from the first-band detection beam emitted by the solid-state lidar 100 and the second-band beam L2, wherein the second band does not include the first band. Preferably, the receiving optical component 11 is not wavelength selective, and beams in both infrared and visible light bands can pass through indiscriminately. The beam splitting unit 123 is disposed downstream of the optical path of the receiving optical component 122 and is configured to separate the optical paths of the reflected echo L1 of the detection beam and the second-band beam L2. At least one detection unit 121 is disposed downstream of the optical path of the beam splitting unit 123 and is configured to receive the reflected echo L1 of the detection beam from the beam splitting unit 123 and convert it into an electrical signal. At least one imaging unit 124 is disposed downstream of the optical path of the beam splitting unit 123 and is configured to receive the second-band beam L2 from the beam splitting unit 123 and image it.

[0123] According to a preferred embodiment of the present invention, in the solid-state lidar 100, multiple photodetectors of each detection unit 121 are simultaneously activated to receive reflected echoes L1, and each imaging unit 124 includes multiple image sensors. The multiple image sensors of each imaging unit 124 are simultaneously activated to receive beams L2 of the second band and form images. Detection units 121 and imaging units 124 corresponding to the same field of view are simultaneously activated for detection and exposure.

[0124] According to a preferred embodiment of the present invention, in the solid-state lidar 100, the beam splitting unit 123 includes a beam splitting mirror, which causes the reflected echo of the detection beam to be reflected and the beam of the second band to be transmitted, or causes the reflected echo of the detection beam to be transmitted and the beam of the second band to be reflected.

[0125] like Figure 13 As shown, a wavelength beam splitter is used as the beam splitting unit 123. Taking the 940nm wavelength probe light as an example, a 940nm high reflectivity film is coated on the surface of the wavelength beam splitter so that the 940nm wavelength laser is reflected. At least one detector unit 121 is set on the focal plane where the reflected beam converges. Other wavelengths of light can be transmitted through and converge on at least one imaging unit 124 at the focal plane position.

[0126] like Figure 14 As shown, a dichroic coating is applied to the surface of the wavelength-splitting transflector, allowing the 940nm echo beam to be transmitted through and received by the detection unit 121 for distance detection; other wavelengths of light are reflected onto the imaging unit 124 for imaging.

[0127] According to a preferred embodiment of the present invention, such as Figure 15 As shown, the receiving module RX includes a distance sensor array and an image sensor array (such as a CMOS array with an RGGB filter). A beam splitter is set in the receiving optical path to divide the beam converged by the receiving lens group into two parts: probe light and other light. The probe light is the echo light reflected by the target object from the probe light emitted by the transmitting module TX, which is received by the distance sensor array of the receiving module RX for echo signal detection. The other light is received by the image sensor array of the receiving module RX to obtain a color image. Both the distance sensor array and the image sensor array of the receiving module RX are located on the focal plane of the receiving lens group, and the beam splitter separates the probe light and other light and illuminates them onto different sensors.

[0128] The preferred embodiment of this invention employs two transmitting modules, eliminating the need to modify the detector array design of the receiving module. It easily integrates a beam splitter + SPAD / CMOS array scheme. Within the entire measurement range, both sensor arrays can simultaneously observe the exact same target, and the results from the two sensors require minimal physical position registration. This allows for the simultaneous acquisition of depth information and color images. The algorithm is simple, and the two sensor arrays share the receiving optical components, significantly reducing production, assembly, and adjustment costs.

[0129] According to a preferred embodiment of the present invention, such as Figure 16 As shown, the present invention also provides a method 10 for detection using the solid-state lidar 100 as described above, comprising:

[0130] In step S101, the light-emitting unit 111 of the emitting module 110 emits a detection beam to detect the target object;

[0131] In step S102, the detection unit 121 of the receiving module 120 receives the echo of the detection beam reflected by the target object;

[0132] In step S103, the distance to the target is determined based on the time of emitting the probe beam and the time of receiving the echo.

[0133] According to a preferred embodiment of the present invention, the solid-state lidar 100 includes two transmitting modules 110 located on both sides of the receiving module 120. Each transmitting module 110 includes an equal number of light-emitting units 111, and the light-emitting units 111 corresponding to the same detection unit 121 are located on the same straight line. The detection method 10 further includes:

[0134] Two light-emitting units 111 corresponding to the same detection unit 121 emit light simultaneously or alternately.

[0135] According to a preferred embodiment of the present invention, a plurality of lasers of the light-emitting unit 111 are arranged in a strip, and a blind spot laser is provided on the side of the light-emitting unit 111 away from the receiving module 120 in the strip extension direction. The blind spot laser and the light-emitting unit 111 have different detection ranges. The echo of the detection light emitted by the blind spot laser is reflected by the target object and can be received by the detection unit 121 corresponding to the light-emitting unit 111. The detection method 10 further includes: the blind spot laser and the light-emitting unit 111 emit light simultaneously.

[0136] According to a preferred embodiment of the present invention, the plurality of lasers of the light-emitting unit 111 are arranged in a strip, and the emitting module 110 further includes an electrode unit electrically connected to the plurality of lasers of the light-emitting unit 111. The electrode unit includes a plurality of driving ends, and the detection method 10 further includes:

[0137] Drive signals are simultaneously applied to multiple lasers in the light-emitting unit 111 through multiple drive terminals.

[0138] According to a preferred embodiment of the present invention, the electrode unit further includes pads disposed at both ends of the strip-shaped extension direction of the light-emitting unit 111, and the detection method 10 further includes:

[0139] The drive signal is loaded through this pad.

[0140] According to a preferred embodiment of the present invention, the receiving module 120 further includes: a receiving optical component; a beam splitting unit disposed downstream of the optical path of the receiving optical component; at least one detection unit disposed downstream of the optical path of the beam splitting unit; and at least one imaging unit disposed downstream of the optical path of the beam splitting unit. The detection method 10 further includes:

[0141] The receiver optical components receive and converge the echo of the first band detection beam emitted by the solid-state lidar reflected by the target object, as well as the second band beam, wherein the second band does not include the first band.

[0142] The optical path of the probe beam's reflected echo and the second-band beam is separated by a beam splitter unit.

[0143] The reflected echo of the probe beam is received from the beam splitter by at least one detection unit and converted into an electrical signal;

[0144] The second-band beam is received from the beam splitter and imaged by at least one imaging unit.

[0145] The detection method 10 and its technical effects provided by the present invention have been described in the introduction of the solid-state lidar 100 provided by the present invention, and will not be repeated here.

[0146] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A solid-state lidar, comprising: A first transmitting module includes a first VCSEL array extending along a first direction and a second direction, wherein the second direction is perpendicular to the first direction. The second transmitting module includes a second VCSEL array, which extends along the first direction and the second direction. The receiving module includes a SPAD array extending along the first direction and the second direction. The first transmitting module and the second transmitting module are arranged on both sides of the receiving module along the first direction. The SPAD array includes a first SPAD subarray and a second SPAD subarray, which extend along a first direction and a second direction, respectively. The first SPAD subarray and the second SPAD subarray are located at different positions in the first direction and are aligned in the second direction. The first SPAD subarray is configured to receive the echo of the probe light emitted by the first VCSEL array reflected by an object, and the second SPAD subarray is configured to receive the echo of the probe light emitted by the second VCSEL array reflected by an object.

2. The solid-state lidar according to claim 1, characterized in that, The fields of view of the first transmitting module and the second transmitting module have a first overlapping region, which corresponds to the central region of the field of view angle range of the solid-state lidar in the first direction.

3. The solid-state lidar according to claim 1, characterized in that, The first VCSEL array and the second VCSEL array are located on the same plane.

4. The solid-state lidar according to claim 1, characterized in that, The first VCSEL array and the second VCSEL array comprise the same number of VCSELs.

5. The solid-state lidar according to claim 1, characterized in that, The first VCSEL array includes a first VCSEL group extending along the first direction, the second VCSEL array includes a second VCSEL group extending along the first direction, the first SPAD subarray includes a first SPAD group extending along the first direction, the second SPAD subarray includes a second SPAD group extending along the first direction, the first SPAD group and the second SPAD group are aligned in the second direction, the first SPAD group is configured to receive the echo of the probe light emitted by the first VCSEL group reflected by an object, and the second SPAD group is configured to receive the echo of the probe light emitted by the second VCSEL group reflected by an object.

6. The solid-state lidar according to claim 5, characterized in that, The first VCSEL group and the second VCSEL group are aligned in the second direction.

7. The solid-state lidar according to claim 6, characterized in that, The first VCSEL group and the second VCSEL group are configured to emit light in parallel.

8. The solid-state lidar according to claim 5, characterized in that, The first VCSEL array includes a plurality of first VCSEL groups arranged along the second direction, and the second VCSEL array includes a plurality of second VCSEL groups arranged along the second direction.

9. The solid-state lidar according to claim 8, characterized in that, The plurality of first VCSEL groups and the plurality of second VCSEL groups are aligned one-to-one in the second direction.

10. The solid-state lidar according to claim 5, characterized in that, The field of view of the first VCSEL group overlaps with that of the second VCSEL group, and the overlapping area corresponds to the central region of the field of view angle range of the solid-state lidar in the first direction.

11. The solid-state lidar according to claim 1, characterized in that, The first transmitting module further includes a first transmitting optical component, wherein the first VCSEL array is located on the focal plane of the first transmitting optical component, and the second transmitting module further includes a second transmitting optical component, wherein the second VCSEL array is located on the focal plane of the second transmitting optical component.

12. The solid-state lidar according to claim 11, characterized in that, The first transmitting optical component is the same as the second transmitting optical component.

13. The solid-state lidar according to claim 1, wherein the first transmitting module further includes a plurality of first electrodes, one first electrode being electrically connected to a VCSEL in a first VCSEL group, the first electrode being configured to load a driving signal to the VCSEL in the first VCSEL group.

14. The solid-state lidar of claim 13, wherein the first electrode includes a pad for loading the drive signal.

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