Light transmitting module, light detecting module, laser radar and ranging method thereof

Abstract

An embodiment of the present invention provides a light emitting module, a light detection module, a laser radar, and a ranging method thereof, wherein the light emitting module includes: a first planar support plate; a plurality of light emitting lines forming a light emitting array, which is arranged on the first planar support plate, and each light emitting line includes a plurality of light emitting units; the light emitting direction of the light emitting units is perpendicular to the first planar support plate, and the light emitting units in at least two light emitting lines are partially staggered with each other, forming a non-uniform distribution in the vertical direction. The above scheme can achieve a non-uniform distribution of the multi-line laser radar beam in a simple manner, meet the requirements of low power consumption and miniaturization of the laser radar, and reduce the implementation cost.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of optical perception technology, and in particular to a light transmitting module, a light detecting module, a laser radar and a ranging method thereof. Background Art

[0002] LiDAR is a sensor that uses lasers to achieve precise ranging. LiDAR emits laser light, which is reflected by surrounding objects. By measuring the time difference between laser transmission and reception, the precise distance to the object can be calculated. Furthermore, by analyzing the energy level, spectral amplitude, frequency, and phase of the echo pulse, the precise three-dimensional structure of the target object can be determined. By combining scanning or multi-beam technology to expand the field of view, a three-dimensional environmental model, or point cloud, can be constructed. LiDAR has a wide range of applications, including autonomous driving, smart cities / Vehicle to Everything (V2X), and robotics.

[0003] To maximize the three-dimensional information of the scanned area, multi-line LiDARs are currently widely used. These utilize multiple light-emitting units (such as lasers) and corresponding detectors arranged vertically, providing coverage for a wider vertical field of view. The vertical field of view (FOV) is the angle of observation in the vertical direction. Currently, the beams of multi-line LiDARs on the market are generally evenly distributed within a certain range of angles.

[0004] Since the main detection targets of vehicle-mounted laser radar are pedestrians and vehicles on the road, in order to improve the efficiency of laser utilization, a solution has emerged in which the laser radar beam is non-uniformly distributed in the vertical direction. Figure 1A and Figure 1B As shown, the existing solution is that the light emitting module 10 is set on the base 11. By installing multiple support plates 12 on the base 11, multiple lasers 13 are respectively set on the multiple support plates 12. In addition, each laser 13 needs to be pointed, that is, to point in the direction of the center of the light-emitting lens group (not shown). By having the multiple support plates 12 spaced apart in the vertical direction / longitudinal direction (i.e., the Y direction in the figure) at different relative intervals, the laser radar's transmitted light beam is non-uniformly distributed in the vertical direction.

[0005] However, this approach, which relies on multiple support plates to achieve a non-uniform vertical distribution of the LiDAR's beam, is bulky and difficult to meet the trend toward low power consumption and miniaturization of LiDAR. Furthermore, this approach is complex to install and adjust in practice, resulting in high implementation costs.

[0006] The contents of the background technology section are merely technologies known to the public and do not necessarily represent the existing technologies in this field. Summary of the Invention

[0007] In view of this, an embodiment of the present invention provides a light transmitting module, a light detecting module, a laser radar and a ranging method thereof, which can realize the non-uniform distribution of multi-line laser radar beams in a simple manner, meet the requirements of low power consumption and miniaturization of the laser radar, and reduce the implementation cost.

[0008] First, one aspect of an embodiment of the present invention provides an optical transmission module, including:

[0009] a first planar support plate;

[0010] A plurality of light emitting line arrays constitute a light emitting array, which is arranged on the first planar support plate, and each light emitting line array includes a plurality of light emitting units;

[0011] The light emitting directions of the light emitting units are perpendicular to the first planar support plate, and the light emitting units in at least two light emitting lines are partially staggered with each other, forming a non-uniform distribution in the vertical direction.

[0012] Optionally, the plurality of light emitting line arrays are arranged such that the density of the light emitting units near the middle region of the first planar support plate in the vertical direction is greater than the density of the light emitting units near the upper and lower sides.

[0013] Optionally, the arrangement density of the plurality of light emitting line arrays in the vertical direction decreases uniformly or gradually from the middle to the upper and lower sides.

[0014] Optionally, the light emitting array is a light emitting unit encrypted area within a vertical field angle range of ±5°.

[0015] Optionally, the plurality of light emitting line columns in the light emitting array are distributed in multiple columns, and the light emitting units in different light emitting line columns are located in different rows.

[0016] Optionally, the spacing between the light emitting units in the light emitting line array is the same or unevenly distributed.

[0017] Optionally, the light emitting module is used for a laser radar and is arranged at the focal plane position of the transmitting end of the laser radar, and also includes a field lens, which is suitable for converging the light emitted by the light emitting unit to pull the light emitted by the light emitting unit back to the optical axis of the transmitting end.

[0018] Optionally, the light emitting module further includes a lens group, adapted to deflect the light emitted by the light emitting unit so that the light emitted by the lasers emitting light perpendicularly to the first planar support plate can cover the entire vertical field of view of the laser radar.

[0019] Optionally, a pitch of the light emission array formed by the plurality of light emission line columns is greater than or equal to a pitch of a single light emission line column divided by the number of staggered columns.

[0020] Optionally, the overlap of the light spots of adjacent light emitting units is slightly smaller than the center distance between two adjacent light emitting units.

[0021] Optionally, the light emitting unit includes at least one of the following: a vertical cavity surface emitting laser, a photonic crystal surface emitting semiconductor laser.

[0022] Optionally, the plurality of light emitting line arrays provided on the first planar support plate have the same specifications or different specifications.

[0023] Secondly, another aspect of the embodiments of the present invention further provides a light detection module, including:

[0024] a second planar support plate;

[0025] A plurality of light detection lines constitute a light detection array, which is arranged on the second planar support plate. Each light detection line includes a plurality of light detection units, and the light detection units in at least two light detection lines are partially staggered with each other to form a non-uniform distribution in the vertical direction.

[0026] Optionally, the plurality of light detection lines are arranged such that the density of the light detection units near the middle region of the second planar support plate in the vertical direction is greater than the density of the light detection units near the upper and lower sides.

[0027] Optionally, the light detection module is used for a laser radar, is arranged at a focal plane position of a receiving end of the laser radar, and further includes an aperture and a filter, wherein:

[0028] The aperture is adapted to block stray light;

[0029] The filter is suitable for allowing only light corresponding to the wavelength of the detection light beam emitted by the transmitting end of the laser radar to pass through and then be incident on the light detection unit.

[0030] Another aspect of the present invention provides a laser radar, comprising: a light emitting module and a light detection module arranged corresponding to the light emitting module, wherein:

[0031] The light emitting module is arranged on the focal plane of the emitting end and includes:

[0032] a first planar support plate;

[0033] A plurality of light emitting line arrays constitute a light emitting array and are disposed on the first planar support plate, each light emitting line array comprising a plurality of light emitting units; the light emitting directions of the light emitting units are perpendicular to the first planar support plate, and the light emitting units in at least two light emitting line arrays are partially staggered with each other, forming a non-uniform distribution in the vertical direction;

[0034] The light detection module is arranged on the focal plane of the receiving end and includes:

[0035] a second planar support plate;

[0036] A plurality of light detection lines constitute a light detection array, which is arranged on the second planar support plate. Each light detection line includes a plurality of light detection units, and the light detection units in at least two light detection lines are partially staggered with each other to form a non-uniform distribution in the vertical direction.

[0037] Another aspect of the embodiments of the present invention further provides a laser radar ranging method, including:

[0038] Respectively controlling the light emitting array to emit light pulses and controlling the light detecting array to receive light reflected by external obstacles; wherein: the light emitting array and the light detecting array are arranged correspondingly; the light emitting array includes a plurality of light emitting line arrays, each of which is arranged on a first plane, and each of which includes a plurality of light emitting units, whose light emitting directions are perpendicular to the first plane and are non-uniformly distributed in the vertical direction; the light detecting array includes a plurality of light detecting line arrays, each of which is arranged on a second plane, and each of which includes a plurality of light detecting units;

[0039] The position information of the obstacle is calculated based on the detection data of the light detection array, and the detection data of the light detection array within the entire field of view is merged into one frame and output as a point cloud.

[0040] The light emitting module of the embodiment of the present invention is provided with a light emitting array composed of a plurality of light emitting lines on a single first planar support plate, and since the light emitting direction of the light emitting unit is perpendicular to the first planar support plate, the light emitting units in at least two light emitting lines are partially staggered in the vertical direction, thereby realizing a non-uniform distribution of the light beam in the vertical direction in a simple and compact manner, which can improve the overall energy density of the light emitting module, and the light emitting efficiency can also be improved by staggering the light emitting units in at least two light emitting lines in the vertical direction, thereby improving the ranging capability of the multi-line laser radar, reducing the power consumption of the laser radar, and meeting the requirements of miniaturization of the laser radar. In addition, since the structure is simple and compact, easy to implement, and convenient to assemble and adjust, the implementation cost can be reduced.

[0041] Furthermore, due to the arrangement of the multiple light emitting line arrays, the density of the light emitting units near the middle area of ​​the first planar support plate in the vertical direction is greater than the density of the light emitting units near the upper and lower sides, so that the detection light beam can be focused on the main area where the target usually appears in the field of view. Therefore, while meeting the detection requirements, the luminous efficiency can be further improved and the overall power consumption of the lidar can be reduced.

[0042] Furthermore, since the arrangement density of the plurality of light emitting line arrays in the vertical direction decreases uniformly or gradually from the middle to the upper and lower sides, the luminous efficiency can be further improved while ensuring the detection accuracy.

[0043] Furthermore, the spacing between the light emitting units in the light emitting line array tends to change uniformly or gradiently, which can further improve the luminous efficiency and reduce the overall power consumption of the laser radar while meeting the detection requirements.

[0044] Furthermore, the overlap of the light spots of adjacent light emitting units is slightly smaller than the center distance between two adjacent light emitting units, which can make the system resolution corresponding to the area of ​​interest reach the limit, further improve the energy density of the light emitting module, and accordingly improve the ranging capability of the laser radar as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0046] Figure 1A and Figure 1B The following are structural diagrams of a light emitting module in the prior art from different perspectives;

[0047] Figure 2A A schematic diagram of the planar structure of an optical transmission module according to an embodiment of the present invention is shown;

[0048] Figure 2B Shown Figure 2A The schematic diagram of the light beam distribution of the light emitting module in the vertical field of view is shown;

[0049] Figure 3A and Figure 3B Schematic diagrams of the optical path of an optical transmitter module at the transmitting end are respectively shown;

[0050] Figure 4A A schematic diagram of the planar structure of an optical transmission module according to an embodiment of the present invention is shown;

[0051] Figure 4B Shown Figure 4A The schematic diagram of the light beam distribution of the light emitting module in the vertical field of view is shown;

[0052] Figures 5A to 5D Schematic diagrams of the planar structures of some optical transmission modules in the embodiments of the present invention are shown in sequence;

[0053] Figure 6 A schematic diagram showing a specific application scenario of an optical transmitter module in a vehicle driving process is shown;

[0054] 7A to 7C Schematic diagrams of the planar structures of other optical transmission modules according to the embodiments of the present invention are shown in sequence;

[0055] Figure 8 A schematic diagram of encrypted light spots of adjacent lasers is shown;

[0056] Figure 9 A schematic structural diagram of a light emitting unit according to an embodiment of the present invention is shown;

[0057] Figure 10 A schematic structural diagram of a light emitting array according to an embodiment of the present invention is shown;

[0058] Figure 11A and Figure 11B Schematic diagrams of the planar structures of two optical transmission modules in the embodiments of the present invention are respectively shown;

[0059] Figure 12 A schematic structural diagram of a laser radar according to an embodiment of the present invention is shown;

[0060] Figure 13 A schematic structural diagram of a light detection array according to an embodiment of the present invention is shown;

[0061] Figure 14A and Figure 14B Schematic diagrams of the planar structures of two light detection modules in an embodiment of the present invention are respectively shown;

[0062] Figure 15A and Figure 15B A schematic diagram showing an optional example of the field of view relationship between the light emitting module and the light detecting module in an embodiment of the present invention is shown;

[0063] Figure 16 A schematic structural diagram of a light detection unit in an embodiment of the present invention is shown.

[0064] Figure 17A A schematic diagram showing the corresponding relationship between the horizontal scanning process and the generated point cloud during non-patrol lighting is shown;

[0065] Figure 17B A schematic diagram showing the corresponding relationship between channels and point clouds of a horizontal scanning mechanical radar when it is not patrolling.

[0066] Figure 18A A schematic diagram showing the corresponding relationship between the horizontal scanning process and the generated point cloud during patrol lighting is shown;

[0067] Figure 18B A schematic diagram showing the corresponding relationship between channels and point clouds of a horizontal scanning mechanical radar during patrol lighting.

[0068] Figure 19 A flow chart of a laser radar ranging method in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0069] For multi-line lidar, the transmitting end is equipped with multiple lasers. These lasers act as light emitting units, emitting multiple beams. These beams are unevenly distributed within the lidar system's vertical field of view. That is, the vertical spacing of all beams is not completely uniform. Because of the correspondence between transmission and reception, there will be at least partial overlap in the field of view (the light emitted by the transmitting end falls on a certain area on the target, and the reflected light energy from this area is precisely reflected back to the detector at the receiving end). As a result, the resolution of all point clouds is not uniform. This is called uneven distribution of beams (or beams, or point clouds). For multi-line lidar, these beams are called scanning beams. The number of scanning beams is the number of laser transmission and reception channels, or the minimum number of addressable channels. Generally, the lasers and detectors are configured in a 1:1 ratio. The number of scanning beams equals the number of lasers or detectors, and thus the number of transmitting or receiving channels. However, there are also cases where multiple detectors share a single laser, or vice versa, or even staggered. In these cases, the scanning beams can be determined by distinguishing the minimum number of addressable channels.

[0070] As mentioned in the previous background section, current solutions for achieving non-uniform beam distribution struggle to balance the high measurement accuracy requirements with the low power consumption and miniaturization requirements in practical applications. Furthermore, this can lead to significant complexity in assembly and debugging.

[0071] In response to the above problems, one aspect of an embodiment of the present invention provides, at the transmitting end, a light emitting module capable of achieving non-uniform distribution of light beams. Specifically, by arranging a light emitting array consisting of a plurality of light emitting lines on a planar support plate (hereinafter referred to as a first planar support plate for ease of description), there is no need for multiple support frames, and since the light emitting directions of the light emitting units are all consistent and perpendicular to the plane of the first planar support plate, there is no need to make each light emitting unit deflect to different directions on each support frame through complex adjustment to achieve that all light beams are directed to the center, and the light emitting units in at least two light emitting lines are partially intertwined with each other, thereby achieving non-uniform distribution of light beams in the vertical direction in a simple and compact manner.

[0072] According to another aspect of an embodiment of the present invention, at the receiving end, a light detection module with non-uniformly distributed light detection units is provided. In a specific implementation, the receiving end and the transmitting end have a corresponding relationship (at least part of their fields of view overlap to achieve detection of objects within at least the overlapping fields of view), and a similar layout is also used. Therefore, the resolution of all line bundles or the entire point cloud in the vertical direction is not completely consistent, that is, a non-uniform distribution.

[0073] Another aspect of the embodiments of the present invention provides a laser radar, which may include the light transmitting module in the embodiment of the present invention at the transmitting end, and the light detecting module in the embodiment of the present invention at the receiving end. By using the light transmitting module for environmental perception, non-uniformly distributed point cloud data can be generated in the vertical direction of the field of view. Since the structure of the transmitting and receiving ends (transmitting end and receiving end) is simple and compact, the ranging capability and measurement accuracy of the multi-line laser radar can be improved, and the demand for miniaturization of the laser radar can be met. Moreover, since all the light transmitting units in the light transmitting module are arranged on a planar support plate (i.e., the first planar support plate), there is no need to make each light transmitting unit point to the center, but the light transmitting unit can be directly attached to the planar support plate, which is very convenient for installation and adjustment.

[0074] Considering cost factors, whether the light emission lines are interleaved, and the specific interleaving area and degree can be designed according to actual conditions. For example, the interleaving can be set based on the area where the target to be measured usually appears in the vertical field of view.

[0075] In a specific implementation, for the light emitting module, each light emitting unit can be directly mounted on the first planar support plate through the patch process. Similarly, for the light detection module, each light detection unit can also be directly mounted on the second planar support plate through the patch process.

[0076] The laser radar provided by the embodiment of the present invention has a compact structure because both the transmitting end and the receiving end adopt this planar device design. In this way, the two can use a symmetrical optical path, and the light alignment efficiency is very high. In addition, the first planar support plate of the transmitting end and the second planar support plate of the receiving end are both perpendicular to the optical axis. When the optical-mechanical structure is slightly deformed due to temperature or stress, especially the warping of the first planar support plate and / or the second planar support plate itself, it will not cause serious changes in the light alignment position. In other words, the correspondence between the transmitting and receiving channels is basically stable. In this way, as long as sufficient patch accuracy is guaranteed, the overall light alignment can be achieved, greatly saving installation and adjustment time.

[0077] Furthermore, the light emitting unit itself does not need to be centrifuged. Instead, a telecentric optical path is used. This means placing a field lens near the focal plane to bring the optical path back to the optical axis. This also improves the patch efficiency of the light emitting unit itself. This reduces the overall implementation cost of the LiDAR.

[0078] In order to enable those skilled in the art to better understand the technical concepts and principles of the embodiments of the present invention and understand its technical advantages and effects, the following is a detailed description with reference to some specific application examples in conjunction with the accompanying drawings.

[0079] First, refer to Figure 2A As shown in the schematic diagram of the planar structure of a light transmitting module, in an embodiment of the present invention, as Figure 2A As shown, the light emitting module A0 may include: a first planar support plate AB0, and a light emitting array AX0 consisting of a plurality of light emitting line arrays (for example, AL1, AL2, and AL3), wherein the light emitting array AX0 is disposed on the first planar support plate AB0. Each light emitting line array includes a plurality of light emitting units AU, which are arranged in a vertical direction, and the light emitting direction of each light emitting unit AU is perpendicular to the first planar support plate AB0, wherein the light emitting units in at least two light emitting line arrays partially overlap each other in the vertical direction to form an encrypted area.

[0080] For example, specifically Figure 2A The light emitting array AX0 shown in FIG. 1 includes light emitting line arrays AL1 and AL2 located in column 0 and light emitting line array AL3 located in column 1, wherein the light emitting line array AL1 and the light emitting line array AL3 are interlaced with each other in the VA0 region in the vertical direction. More specifically, as shown in FIG. Figure 2A As shown, in the vertical direction, light emitting unit AU30 in light emitting line array AL3 is interleaved between light emitting unit AU12 and light emitting unit AU13 in light emitting line array AL1, and light emitting unit AU31 is interleaved between light emitting unit AU13 and light emitting unit AU14. The light emitting unit AU can be a laser. As an alternative example, the light emitting unit AU can be a vertical cavity emitting unit.

[0081] With the above solution, it is only necessary to set a light emitting array AX0 consisting of a plurality of light emitting lines on a single first planar support plate AB0, and since the light emitting direction of the light emitting unit AU is perpendicular to the first planar support plate AB0, the light beams formed by the light emitting units AU in at least two light emitting lines are intertwined in the vertical direction. Figure 2A as well as Figure 2B ,Since the light emitting line array AL1 and the light emitting line array AL3 are intertwined in the vertical area OL0, accordingly, the distribution of all beams / point clouds of the radar in the vertical field of view is uneven, so the resolution of the light beam within the area OL0 in the vertical direction is higher, such as Figure 2B As shown, the emitted light beam is in the vertical field of view V11 area (corresponding to Figure 2AThe density in the vertical direction VA0 range) is greater than the density in the field of view areas V12 and V13.

[0082] In addition, due to the corresponding transmission and reception, the radar can achieve the vertical field of view V11 area (corresponding to Figure 2A The resolution or point cloud density of VA0) in the field of view is greater than the resolution or point cloud density in the field of view areas V12 and V13.

[0083] In a specific implementation, the planar support plate AB0 may be a printed circuit board (PCB), and the embodiment of the present invention does not limit its specific outline shape and structure.

[0084] In a specific implementation, the light emitting unit AU can be a vertical cavity emitting laser, for example, a vertical cavity surface emitting laser (VCSEL), a photonic crystal surface emitting semiconductor laser (PCSEL), etc.

[0085] VCSELs, because their beams are emitted perpendicular to the substrate, are easy to integrate in two dimensions and achieve wafer-level manufacturing. They offer advantages such as low power consumption, small temperature drift coefficient, strong robustness, and low cost. PCSELs, which emit laser light from the top surface, are therefore easy to package and integrate into printed circuit boards and electronic components. They have the advantages of low cost, strong robustness, a wide wavelength range, and high power.

[0086] In addition, in a specific implementation, since all light emitting units (such as lasers) emit light perpendicular to the first planar support plate, in order to achieve detection within a certain vertical field of view, the transmitting end can use a telecentric optical path to complete the centering of the laser light emitting direction, so as to improve the transmittance of each channel in the lens. The main feature of the telecentric optical path is to set the light emitting array (such as a laser array) on the focal plane of the emitting light path, and then design a lens within a certain distance range near the focal plane, such as 15mm, also called a field lens, to pull the light emitted by the light emitting unit (such as a laser) back to the optical axis of the emitting light path. For example, referring to the optical path diagram of the transmitting end shown in FIG3, the lasers La01 to La03 are all set on the first planar support plate AB3a. Although the emitted light is perpendicular to the direction of the support plate, it is shaped and deflected by the field lens FL0 and other lens groups LA0 and then emitted outside the radar. In this way, the light emitted by all the lasers of the laser radar will cover the entire laser radar in the vertical direction (Field of View, FoV) range. In addition, for the receiving end, a corresponding planar detection module is provided, which is arranged on the focal plane of the receiving end. The laser beam emitted by the transmitting end is reflected after encountering an external obstacle, and at least part of the light returns to the detection module, passes through the aperture, and is blocked by some stray light outside the preset FoV. Then, it passes through the filter, and only the light corresponding to the wavelength f0 of the detection beam emitted by the transmitting end of the laser radar (within a certain pulse width, f0±Δf) is allowed to pass through and enter the light detection unit, so as to realize detection in the vertical field of view. Combined with a rotating mirror or a galvanometer or a micro electromechanical system (MEMS) or a rotating scanning accessory of a traditional mechanical radar or an optical phased array (OPA) or a liquid crystal, the horizontal scanning field of view is expanded, so that the scanning and detection of obstacles within a certain horizontal field of view and a certain vertical field of view can be realized.

[0087] Moreover, in order to improve the transmittance of the light emitted by the light emitting unit in the lens group, as Figure 3B As shown, a microlens array mLX may be further installed on the light-emitting side of each laser (eg, Lb01 to Lb03) to further compress the divergence angle.

[0088] It should be noted that the above description is merely exemplary, and the embodiment of the present invention does not limit the specific type of the light emitting unit used, as long as the light emitting direction is perpendicular to the first planar support plate.

[0089] In a specific implementation, taking into account the actual application scenarios of the light emitting module, for example, the light emitting module can be applied to a laser radar. If the laser radar is used as a sensing device for equipment such as autonomous driving, advanced driver assistance systems (ADAS) or robots, and mainly detects pedestrians on the ground and moving vehicles, then, outside the area where the target may appear, for example, the light beam directed to the sky high up is largely wasted. To this end, the arrangement of the multiple light emitting line arrays can be set in a targeted manner so that the density of the light emitting units in the central area near the first planar support plate in the vertical direction is greater than the density of the light emitting units near the upper and lower sides.

[0090] For example, continue to refer to Figure 2A and Figure 2B , where the density of light emitting units in the OL0 area is greater than the density of light emitting units in the upper and lower areas. Accordingly, the density of the radar beam or point cloud in the vertical field of view V11 area is greater than the density in the field of view areas V12 and V13.

[0091] Then refer to Figure 4A The planar structural diagram of the optical transmitter module shown in FIG. Figure 4B The schematic diagram of the distribution of the corresponding emission light beams in the vertical field of view area is shown. The difference between the light emission module A1 and the light emission module A0 is that in the light emission array AX1, the distance between the light emission module AL1 and the light emission module AL2 located in the 0th column is closer, the structure is more compact, and the position of the light emission line column AL3 located in the 1st column is more centered. For example, it can be horizontally symmetrical along the midline between the light emission line columns AL1 and AL2, so that the light emission line column AL3 is staggered with the light emission line columns AL1 and AL2 in the vertical direction. In this way, in the vertical field of view, the density of the radar beam or point cloud in the vertical field of view V21 area is greater than the density in the field of view areas V22 and V23, and the coverage of the beam in the field of view areas V22 and V23 is roughly equal. In addition, the multiple light emission line columns in the light emission array are distributed in multiple columns, and the light emission units in different light emission line columns are located in different rows. Reference Figure 4A The light emitting line arrays AL1, AL2 and AL3 constitute a light emitting array, which is distributed in 2 columns. That is, along the Y direction in the figure, the light emitting units AU in the light emitting line arrays AL1 and AL3 are distributed on different rows, that is, in the X direction dimension, they are located at different positions.

[0092] Another example Figure 5AAs shown, the optical transmission module A2 includes a first planar support plate AB2 and a light transmission array AX2 disposed on the first planar support plate AB2. The light transmission array AX2 includes multiple light transmission line arrays AL1 to AL5 arranged in two vertical columns. The light transmission line array AL4 in column 1 partially intersects with the light transmission line arrays AL1 and AL2 in column 0, and the light transmission line array AL5 in column 1 partially intersects with the light transmission line arrays AL2 and AL3 in column 0. This results in a higher vertical resolution of the radar beam or point cloud formed by the corresponding light transmission units within area OL2.

[0093] In a specific implementation, a light emitting array can be composed of multiple columns of light emitting lines, and the multiple light emitting line columns can have multiple levels of vertical arrangement based on the differences in density. As an optional example, the vertical arrangement density of the multiple light emitting line columns decreases uniformly or gradually from the center to the top and bottom, thereby further improving luminous efficiency while ensuring detection accuracy.

[0094] like Figure 5B As shown, the light emitting module A3 includes a first planar support plate AB3 and a light emitting array AX3 disposed on the first planar support plate AB3. The light emitting array AX3 includes a plurality of light emitting line arrays AL1 to AL6, which are divided into three vertically distributed columns. Figure 5A The difference of the light emitting array AX2 shown is that the light emitting array AX3 also includes a light emitting line column AL6 located in the second column, and the light emitting line column AL6 is also partially staggered with the light emitting line columns AL4 and AL5 located in the first column, thereby forming an area in the vertical direction from the light emitting line column AL6 and the light emitting line columns AL2 in the 0th column and the light emitting line columns AL4 and AL5 in the 1st column are staggered, to the areas on the upper and lower sides where only the light emitting line column AL4 in the 1st column is partially staggered with the light emitting line column AL1 in the 0th column, and the areas where the light emitting line column AL5 in the 1st column is partially staggered with the light emitting line column AL3 in the 0th column, to the areas on the upper and lower sides where some light emitting units in the light emitting line columns AL1 and AL3 in the 0th column are distributed without any staggering with other columns, and the density decreases gradually. The resolution of the emitted light beam of the light emitting array AX3 in the vertical direction decreases gradually from the middle to the upper and lower sides.

[0095] Another example Figure 5C The schematic diagram of the planar structure of another optical emission module shown in FIG. 4 shows that the optical emission module A4 includes a first planar support plate AB4 and an optical emission array AX4 arranged on the first planar support plate AB4. Figure 5BThe difference of the light emitting module A3 shown is that the light emitting array AX4 further includes a light emitting line array AL7 located in the third column. The number of light emitting units included in the light emitting line array AL7 is different from the number of light emitting units included in the other light emitting line arrays. Figure 5C As shown, it includes 4 light emitting units, while the other light emitting line columns AL1 to AL6 each contain 8 light emitting line columns, and the light emitting line column AL7 is also staggered with the light emitting line column AL6 located in the second column in the vertical direction, so that the resolution of the emission light beam of the light emitting array AX4 in the vertical direction forms a non-uniform distribution with a gradient decreasing from the middle area to both sides.

[0096] In an embodiment of the present invention, the number of light emitting units contained in each light emitting line column is not limited, and the number of light emitting units in each light emitting line column in the same light emitting array can be the same or different, so as to achieve non-uniform distribution of the emission light beam of the light emitting module in the vertical direction and meet the target detection requirements in specific application scenarios.

[0097] In a specific implementation, the plurality of light emitting line columns may be distributed in a plurality of columns along the vertical direction, and adjacent columns of light emitting line columns may also be staggered with each other in the vertical direction. Figure 5D The schematic diagram of the planar structure of the light emitting module shown in FIG. The light emitting module A5 includes a first planar support plate AB5 and a light emitting array AX5 disposed on the first planar support plate AB5. The light emitting array AX5 includes three columns, wherein a portion of the light emitting line array AL4 located in the first column is partially interleaved with the light emitting line array AL1 located in the zero column, and another portion is partially interleaved with the light emitting line array AL6 located in the second column; a portion of the light emitting line array AL5 located in the first column is partially interleaved with the light emitting line array AL2 located in the zero column, and another portion is partially interleaved with the light emitting line array AL7 located in the second column. This results in an alternating density distribution of the light emitting array AX5 in the vertical direction, causing the radar's beam or point cloud to also exhibit a non-uniform alternating density distribution.

[0098] As mentioned above, considering cost factors, whether the light emitting lines are staggered and the specific staggered areas can be designed according to actual conditions. For example, if the light emitting module is used for a laser radar and installed on a vehicle, ranging can be achieved during autonomous driving. For example, the detection requirement is to detect targets within a range of 200 meters. It can be understood by those skilled in the art that the detection distance capability requirement is positively correlated with the vehicle speed. For example, only when the vehicle speed is very high, generally on a highway, is it necessary to see targets 200 meters away clearly. Therefore, the required ranging capability of the laser radar is directly related to the vehicle speed. The higher the speed, the longer the distance the laser radar is expected to detect. The vehicle speed is correlated with the road inclination. Generally, the greater the inclination, the lower the maximum speed. This is because, based on driving safety requirements, it is necessary to slow down when going up and downhill.

[0099] In addition, according to the requirements of road design, the slopes of roads with different speed levels are also different. For example, Table 1 shows a comparison table of road design parameter information for different levels in China.

[0100] Design speed (km / h) 120 100 80 60 40 30 20 Maximum longitudinal slope (%) 3 4 5 6 7 8 9 Road surface inclination (°) 1.72 2.29 2.87 3.44 4.01 4.59 5.16

[0101] Table 1 Comparison table of pavement design parameter information for different speed levels in China

[0102] Assume the most extreme case: the vehicle speed is 120km / h and the road surface has an inclination angle of ±2°, which is the inclination angle corresponding to the vehicle speed of approximately 120km / h in Table 1, where +2° represents uphill and -2° represents downhill. If you need to see a target 200 meters away clearly, the light emission lines within the vertical field of view range of ±4° need to be staggered, that is, the light emission array includes at least two light emission lines within the vertical field of view range of ±4°. Figure 6 As shown, if vehicle C0 is at the top of the slope and the laser radar (not shown in the figure) is horizontally installed on the top or front of the vehicle C0, it is necessary to increase the distribution density of the light emitting units within the vertical field of view of 0 to -4°, which is beneficial to improve the detection resolution of objects 200 meters ahead.

[0103] In the specific application process, taking into account the design margin, the laser radar can be set to perform point cloud encryption within the vertical field of view angle of ±5°. In the specific implementation, the light emitting array can increase the density of the light emitting units within the vertical field of view angle of ±5° to form an encrypted area, thereby improving the detection efficiency.

[0104] In some embodiments of the present invention, in a light emitting array, a plurality of light emitting line columns may be distributed in multiple columns along the vertical direction, and for a light emitting line column located in a relatively middle area of ​​the first planar support plate, one end thereof may be connected end to end with a light emitting line column in an adjacent column, and the other end may be staggered with the light emitting line column in the adjacent column in the vertical direction.

[0105] like Figure 2A As shown, in the light emitting array AX0, the multiple light emitting units at the upper end of the light emitting line array AL3 located in the 1st column are interlaced with the VA0 area of ​​the light emitting line array AL1 located in the 0th column in the vertical direction to form an encrypted one-dimensional array area; the lower end of the light emitting line array AL3 located in the 1st column is connected end to end with the light emitting line array AL2 located in the 0th column to form a relatively sparse one-dimensional array area.

[0106] Another example Figure 5D As shown, in the light emission array AX5, the upper end of the light emission line array AL4 located in the first column is vertically interlaced with the light emission line array AL1 located in the zero column; its lower end is vertically intersected end to end with the light emission line array AL2 located in the zero column, and is vertically interlaced with the light emission line array AL6 located in the second column. Similarly, the upper end of the light emission line array AL5 located in the first column is vertically interlaced with the light emission line array AL2 located in the zero column; its lower end is vertically intersected end to end with the light emission line array AL3 located in the zero column, and is vertically interlaced with the light emission line array AL7 located in the second column. The above arrangement constitutes a one-dimensional array with a sparse and dense spacing distribution.

[0107] In a specific implementation, the spacing between the light emitting units in the light emitting line is the same, such as Figure 2A 、 Figure 4A 、 5A to 5D As shown, it can also be distributed unevenly, which is illustrated below with reference to the accompanying drawings.

[0108] Reference Figure 7A The planar structural schematic diagram of the light emitting module shown in the figure, the light emitting module A6 includes a first planar support plate AB6 and a light emitting array AX6 arranged on the first planar support plate AB6, wherein the light emitting array AX6 includes light emitting line arrays AL1 and AL2 located in the 0th column, and a light emitting line array AL3 located in the 1st column. The difference from the aforementioned embodiments is that the spacing between the light emitting units AU included in the light emitting line arrays AL1 and AL2 located in the 0th column is different, while the spacing between the light emitting units AU in the light emitting line array AL3 located in the 1st column is the same.

[0109] In a specific implementation, the spacing between the light emitting units in the light emitting line array tends to change uniformly or gradually. As some optional examples, the spacing between the light emitting units in the plurality of light emitting line arrays tends to increase from the center to both sides, or tends to increase from one end to the other. Figure 7AIn the light emitting array AL1, the spacing between each light emitting unit AU in the light emitting array AL1 gradually increases from the lower end to the upper end, while the spacing between each light emitting unit AU in the light emitting array AL2 gradually increases from the upper end to the lower end.

[0110] like Figure 7B As shown, in the light emitting module A7, the light emitting array AX7 arranged on the first planar support plate AB7 includes relatively symmetrical light emitting line arrays AL1 and AL2 in the 0th column, and the light emitting line array AL3 in the 1st column, and the light emitting units in the light emitting line arrays AL1 to AL3 are all arranged unevenly.

[0111] Among them, Figure 7B As shown, the light emitting units AU in the 0th column together form an arrangement structure with gradually increasing spacing from the middle area of ​​the first planar support plate AB7 to the upper and lower sides, and in the 1st column, the light emitting line array AL3 is staggered with the light emitting line arrays AL1 and AL2 in the 0th column in the vertical direction, and the light emitting units AU in the light emitting line array AL3 are gradually increased in spacing from bottom to top in the vertical direction, thereby forming a non-uniform distribution of the light beam of the light emitting array AX7 and the overall line beam and point cloud of the radar in the vertical direction, and forming an overall arrangement with gradually decreasing density from the lower middle area to both sides.

[0112] As for the optical transmitter module A8, refer to Figure 7C , in the light emitting array AX8 provided on the first planar support plate AB8, each light emitting unit in the light emitting line arrays AL1 to AL3 is also arranged non-uniformly. Figure 7C As shown, the light emitting units AU in the light emitting line arrays AL1 and AL2 in the 0th column are arranged with gradually increasing intervals from the lower end to the upper end in the vertical direction, while in the 1st column, the light emitting units in the light emitting line array AL3 are arranged with gradually increasing intervals from the upper end to the lower end in the vertical direction, and the light emitting line array AL3 is respectively staggered with the light emitting line arrays AL1 and AL2 in the 0th column in the vertical direction, thereby forming a non-uniform distribution of the emission light beams of the light emitting array AX8 in the vertical direction.

[0113] In a specific implementation, sufficient bonding and routing space is reserved between the light emitting line columns in the light emitting array according to process requirements.

[0114] In a specific application, the pitch of the array formed by the plurality of light emitting line columns is equal to the pitch of a single light emitting line column divided by the number of staggered columns. Figure 2A As shown, the pitch of a single light emitting line column refers to the distance between two adjacent light emitting units in the same column, such as Figure 2AThe first pitch pt0 in the light emitting array refers to the distance between the adjacent light emitting units in the vertical direction in two columns of light emitting lines staggered in the vertical direction, such as Figure 2A The second pitch pt1 in , then pt1 = pt0 / 2.

[0115] In a specific implementation, each light emitting array can be independently packaged as a chip or device. Considering the yield rate of semiconductor devices, it is necessary to impose certain restrictions on the aspect ratio of each light emitting array. In an embodiment of the present invention, the aspect ratio of the light emitting array can be set between 1:1 and 10:1. In specific application scenarios, the light emitting array may need to form a one-dimensional array of 30:1 or even 60:1. To this end, the method of splicing multiple sections of multiple light emitting arrays in the embodiment of the present invention can meet the product yield requirements and have a higher cost-effectiveness.

[0116] In addition, in order to maximize the ranging capability, the light emitting area of ​​the light emitting module needs to be as large as possible, especially when VCSEL is used as the light source. In this case, the vertical height H of the light emitting area may be greater than the density pitch, that is, after the multiple columns are staggered, some overlapping parts of the light spots will appear, which is allowed. Due to the diffraction of light, it may be impossible to distinguish two adjacent light spots visually, such as Figure 8 As shown in the schematic diagram of the encrypted light spots of adjacent lasers, according to the Rayleigh Criterion, when the overlap R of the two light spots is less than 50%, that is, when the half-height width H / 2 of the main lobe of the light spot is equal to the distance R0 between the adjacent light spots without considering the side lobes, that is, H / 2=R0, the two light spots can still be visually separated. Therefore, when the system resolution of the optical transmission module reaches the diffraction limit, the overlap R of the light spots of adjacent light transmission units can be set to be less than the center distance R0 of the two adjacent light transmission units. This can maintain high resolution while maximizing the energy density of the optical transmission module and further improving the ranging capability.

[0117] In a specific implementation, the plurality of light emitting lines arranged on the first planar support plate may have the same specifications or different specifications. Figure 5C As shown, the number of light emitting units included in the light emitting line array AL7 is different from the number of light emitting units included in other light emitting line arrays in the light emitting array AX4. Figure 7AAs shown, the spacing between the light emitting units in the light emitting line array AL3 is different from that in the other light emitting line arrays in the light emitting array AX6. For another example, the dimensions of the light emitting units in the light emitting line arrays can be different. It will be understood that the above is merely an example, and the multiple light emitting line arrays provided on the same first planar support plate can also have different specifications and parameters as needed.

[0118] In order to enable those skilled in the art to better understand and implement the embodiments of the present invention, some specific achievable examples of light emitting units are shown below.

[0119] The light emitting unit may specifically include one light emitting point or multiple light emitting points.

[0120] In a specific implementation, the cathodes or anodes of the plurality of light emitting units may be shared, and each light emitting unit may have a connection point electrically connected to the unshared anode or cathode of each corresponding light emitting unit. The connection point may be a wire bonding pad or other form of wiring component.

[0121] In some embodiments of the present invention, the light emitting unit may include a plurality of light emitting blocks, wherein each light emitting block includes at least one light emitting point.

[0122] Reference Figure 9 The schematic diagram of the structure of a light emitting unit is shown. Light emitting unit AU0 includes two light-emitting blocks, namely light-emitting block U1 and light-emitting block U2. Light-emitting block U1 and light-emitting block U2 share a common cathode. Light-emitting block U1 has a connection point U1a, and light-emitting block U2 has a connection point U2a. In a specific implementation, light emitting unit AU0 can be a separately packaged laser, wherein light-emitting block U1 and light-emitting block U2 each have a separate substrate. As an optional example, light emitting unit AU0 can be a vertical cavity light-emitting device such as a VCSEL or PCSEL.

[0123] Reference Figure 10 The light emitting array ALi includes a plurality of light emitting units AU0, and the light emitting units AU0 adopt Figure 9 The structure of the light emitting unit shown in FIG2 is shown, and the spacing between each light emitting unit AU0 is the same. It is understandable that in a specific implementation, the spacing between each light emitting unit AU0 may also be different.

[0124] In specific applications, depending on the actual needs of the actual detection application scenario, a control device and a driving device can be used to drive and control the light emitting module. The control device can output a control signal to control the driving device to turn on and off, thereby driving the corresponding emission channels of the light emitting module to emit light. Specifically, a single driving device can be used to control the light emitting units of multiple light emitting lines; different driving devices can be used to control different light emitting lines respectively; or multiple driving devices can be used, each driving device controlling the light emitting of multiple light emitting lines.

[0125] In order to make those skilled in the art better understand and implement, the following is shown: Figure 10 The specific implementation schemes of some optical transmission modules of the optical transmission line array shown are shown.

[0126] First, if Figure 11A The planar structural diagram of the light emitting module shown in FIG. 1 shows that the light emitting module A9 includes a first planar supporting plate AB9 and a light emitting array AX9 and a driving chip CH0 arranged thereon.

[0127] In a specific implementation, the control device (not shown) can be provided on another circuit board or on the first planar support plate AB9. The control device can be implemented using a single-chip microcomputer, a CPU, a field programmable logic array (FPGA) chip, etc. The embodiment of the present invention does not limit the specific implementation form of the control device.

[0128] Continue to refer to Figure 11A The light emitting array AX9 includes a light emitting line array AL1 located in the 0th column and a light emitting line array AL2 located in the 1st column, and the light emitting line array AL2 and the light emitting line array AL1 are partially staggered in the vertical direction, so as to achieve non-uniform distribution of the laser radar beam and point cloud in the vertical field of view, wherein the vertical field of view density of the emitted light beam in the area where the light emitting line array AL2 and the light emitting line array AL1 are staggered in the vertical direction is greater than the vertical field of view density of the non-staggered area.

[0129] In a specific implementation, single-sided driving can be performed, that is, the driver is located on one side of the laser, which can save area. Figure 11A As shown, the connection points of the driver chip CH0 (not shown) can be electrically connected to the connection points of each light emitting unit AU0 in the light emitting line arrays AL1 and AL2 respectively, and the electrical connection between the driver chip CH0 and each light emitting unit AU0 can be completed by wiring inside the first planar support plate AB9.

[0130] In other embodiments of the present invention, multiple driver chips may be used, each driver chip driving one or more light emitting line arrays.

[0131] In a specific implementation, dual-side driving can also be performed, that is, the drivers are located on both sides of the laser, which can improve the driving capability. Figure 11B The schematic diagram of the planar structure of the light emitting module shown in FIG. Light emitting module A10 includes: a first planar support plate AB10, and a light emitting array AX10 and driver chips CH1 and CH2 disposed thereon. The light emitting array AX10 includes a light emitting line array AL1 located in column 0 and a light emitting line array AL2 located in column 1. Driver chip CH1 is used to drive light emitting line array AL1, and driver chip CH2 is used to drive light emitting line array AL2. Light emitting line arrays AL2 and AL1 are partially staggered in the vertical direction, thereby achieving a non-uniform distribution of the emitted light beam in the vertical field of view. The vertical field of view density of the emitted light beam in the area where light emitting line arrays AL2 and AL1 vertically intersect is greater than the vertical field of view density in the area where they do not intersect.

[0132] and Figure 11A The difference of the light emitting module shown is that, on the one hand, the light emitting area of ​​the light emitting unit AU0 in the light emitting line array AL1 and the light emitting line array AL2 is more concentrated, thereby further improving the overall energy density of the light emitting array; on the other hand, the connection points of each light emitting unit AU0 are arranged on both sides of the light emitting array AX10, closer to their respective driver chips, thereby reducing the wiring resistance in the first plane board AB10 and reducing the coupling noise interference between the lines.

[0133] It should be noted that the above figures are only schematic structures for ease of understanding and do not represent the actual structure of the optical transmitter module. Figure 11A and Figure 11B The actual relative size ratio or quantity correspondence between the driver chip and the laser is not limited in the embodiments of this specification.

[0134] As previously mentioned, embodiments of the present invention also provide a light detection module corresponding to the light transmission module in the aforementioned embodiments. The light detection module and the light transmission module can have the same layout structure. In specific applications, for example, the light transmission module and light detection module can be used in a laser radar to detect targets within the target field of view.

[0135] In some embodiments of the present invention, a light detection module is provided, which includes: a second planar support plate; a plurality of light detection lines forming a light detection array, which is arranged on the second planar support plate, each light detection line including a plurality of light detection units, and the light detection units in at least two of the light detection lines are partially staggered with each other, forming a non-uniform distribution in the vertical direction.

[0136] As some optional examples, the arrangement of the multiple light detection lines is such that the density of the light detection units near the middle area of ​​the second planar support plate in the vertical direction is greater than the density of the light detection units near the upper and lower sides.

[0137] In a specific implementation, the plurality of light detection lines in the light detection array are distributed in multiple columns, and the light detection units in different light detection lines are located in different rows.

[0138] Based on the basic implementation principle of radar detection, in order to achieve target detection within the target field of view, the radar's transmitting end and receiving end have at least part of their fields of view overlap, so that the transceiver channels can correspond, and the receiving end and the transmitting end can be symmetrically arranged. Therefore, the optical detection module at the receiving end is also suitable for adopting a similar arrangement and layout as the optical transmission module at the transmitting end. Therefore, the different arrangement and layout embodiments of the transmitting end introduced in the above embodiments, as well as the structure of the accompanying drawings, are also adapted to the structure of the optical detection module at the receiving end. For details, please refer to the specific embodiments and drawings of the aforementioned optical transmission module, which will not be repeated here.

[0139] As mentioned above, the optical transmission module has a wide range of applications, including target detection and control. To better understand and implement the technical field of this field, the following is an example of its specific application in lidar.

[0140] Reference Figure 12 As shown in the structural diagram of the laser radar, the laser radar L0 may include: a light transmitting module TX and a light detecting module RX arranged corresponding to the light transmitting module TX.

[0141] The optical transmitter module TX is arranged on the focal plane of the transmitter end and may include:

[0142] a first planar support plate ABX;

[0143] A plurality of light emitting line columns ALx constitute a light emitting array, which is arranged on the first planar support plate ABX, and each light emitting line column ALx includes a plurality of light emitting units; the light emitting direction of the light emitting unit is perpendicular to the first planar support plate ABX, and the light emitting units in at least two light emitting line columns are partially staggered with each other, forming an uneven distribution in the vertical direction.

[0144] The light emitting array in the light emitting module TX is arranged on the first planar support plate to constitute a planar emitting device. Its specific implementation, working principle, advantages, etc. can be found in the detailed description of the aforementioned embodiments and will not be introduced in detail here.

[0145] Continue to refer to Figure 12 In a specific implementation, the optical detection module RX is arranged on the focal plane of the receiving end, and may specifically include:

[0146] The second plane supports the PBX;

[0147] A plurality of light detection lines RLx constitute a light detection array and are disposed on the second planar support plate PBX. The light detection lines RLx include a plurality of light detection units, and the light detection units in at least two of the light detection lines RLx are partially staggered with each other, forming a non-uniform distribution in the vertical direction.

[0148] The light detection array in the light detection module TX is arranged on the second planar support plate to form a planar receiving device.

[0149] Using the above-mentioned laser radar, each light detection line array RLx corresponds to the corresponding light transmission line array ALx. The light transmission module TX emits a detection beam, and the echo beam reflected by the target object O is received by the light detection module RX and converted into an electrical signal for target detection.

[0150] The light emitting module and the light detecting module are arranged in correspondence with each other in the layout to ensure that their point cloud fields of view overlap, so that the light emitted by the light emitting module can be received by the corresponding light detecting module after being reflected by external obstacles.

[0151] As an optional example, the light detection unit can specifically be a single-photon detection unit, such as a single-photon avalanche photodiode (SPAD) array or a silicon photomultiplier (SiPM), so as to improve the detection sensitivity and enable the detection of extremely weak target signals.

[0152] Reference Figure 13 A schematic diagram of the structure of a light detection array is shown. The light detection array RLi includes multiple light detection units RU. The light detection units RU can be arranged evenly or unevenly. The specific specifications of the light detection array RLi can be set with reference to the corresponding light transmission array Ali, including setting at least one of the following specifications: the specific number of light detection units RU contained therein, the specific size of each light detection unit RU, the spacing between each light detection unit RU, the column spacing between each light detection array, and the specific arrangement of each light detection array. As long as it is ensured that the fields of view of the transmitting and receiving ends can at least partially overlap, the light emitted by the light transmission unit can be at least partially received by the light detection unit (e.g., a detector) after being reflected by an obstacle, and then analyzed to obtain information such as the distance and reflectivity of the obstacle, thereby achieving detection of the obstacle.

[0153] In the specific implementation, continue to refer to Figure 13Each light detection unit RU may include a detection area Ra and a connection point Rb, and at least one light detection unit RU and one light emitting unit AU may form a detection channel. The connection point Rb may be a wire bonding pad or other connection components.

[0154] As mentioned above, the specific structure of the light detection module is consistent with the specific structure of the light transmission module and the positions are corresponding. In order to enable those skilled in the art to better understand and implement, some optional examples are given below.

[0155] Reference Figure 14A and Figure 14B The schematic diagram of the planar structure of the light detection module is shown in FIG. Figure 14A As shown, the optical detection module B0 includes a second planar support plate PB0 and an optical detection array RX0 disposed on the second planar support plate PB0. The optical detection array RX0 includes multiple optical detection lines RL1-RL2, arranged vertically in two columns. Furthermore, a portion of the optical detection line RL2 in column 1 vertically intersects with the optical detection line RL1 in column 0. Accordingly, the system resolution corresponding to the vertically intersecting area is greater than the resolution of the other non-intersecting areas, thereby improving the overall detection capability and accuracy of the system while also balancing the overall system power consumption.

[0156] The light detection lines RL1 and RL2 are both arranged in the same direction, that is, the connection point of each light detection unit is closer to the left side of the second planar support plate PB0, and the corresponding detection point is closer to the right side of the second planar support plate PB0.

[0157] As a specific example, Figure 14A The light detection module B0 shown can be used with similar Figure 11A The light emitting module A9 of the arrangement structure shown is matched and arranged in a laser radar for target detection.

[0158] Then refer to Figure 14B The schematic diagram of the structure of the optical detection module shown in FIG. The optical detection module B1 includes a second planar support plate PB1 and an optical detection array RX1 disposed on the second planar support plate PB1. The optical detection array RX0 includes multiple optical detection lines RL1-RL2, arranged vertically in two columns. Furthermore, a portion of the optical detection line RL2 in column 1 vertically intersects with the optical detection line RL1 in column 0. Accordingly, the system resolution corresponding to the vertically intersecting area is greater than the resolution of the other non-intersecting areas, thereby improving the overall detection capability and accuracy of the system while also balancing the overall system power consumption.

[0159] Among them, Figure 14AThe difference between the optical detection modules shown is that the optical detection line array RL1 and the optical detection line array RL2 are symmetrically arranged along the vertical center line CC, that is, the connection points of the optical detection units in the 0th column of the optical detection line array RL1 are all closer to the left side of the second planar support plate PB1, and the corresponding detection points are closer to the right side of the second planar support plate PB1; while the connection points of the optical detection units in the 1st column of the optical detection line array RL2 are all closer to the right side of the second planar support plate PB1, and the corresponding detection points are closer to the left side of the second planar support plate PB1.

[0160] As a specific example, Figure 14B The light detection module B1 shown can be used with Figure 11B or with Figure 11B A light emitting module A10 of similar structure is matched and set in the laser radar for target detection.

[0161] In summary, the laser radar in the embodiments of this specification can achieve non-uniform point clouds through planar transceiver devices (set on a planar support plate).

[0162] In order to improve the accuracy of light detection and ensure the consistency and stability of the ranging capabilities of each transceiver channel, in the specific application process, the fields of view of the light emitting module and the light detection module in the laser radar can be set to be relatively vertically staggered, and the field of view size of the light emitting module in the first direction is larger than the field of view size of the light receiving module, and the field of view size in the second direction is smaller than the field of view size of the light detection module, and the first direction and the second direction are perpendicular.

[0163] Continue to refer to Figure 12 If the fields of view of the optical transmitter module TX and the optical detector module RX intersect with each other, a certain overlapping area is formed, namely the effective field of view area.

[0164] For example, if the field of view coverage area of ​​the optical transmitter module TX and the optical detection module RX are both rectangular, the first direction and the second direction correspond to two perpendicular side length directions. The field of view size of the optical transmitter module TX in the first direction is V1, and the field of view size in the second direction is H1. The field of view size of the optical detection module RX in the first direction is V2, and the field of view size in the second direction is H2. Then V1>V2, H1<H2. If the optical transmitter module TX and the optical detection module RX adopt the above field of view sizes, the corresponding effective field of view area is V2*H1 / f. 2 , where f is the focal length.

[0165] Reference Figure 15A and Figure 15B The diagram shows an optional example of the field of view relationship between the optical transmitter module TX and the optical detector module RX. The field of view coverage area of ​​the optical transmitter module TX and the optical detector module RX are both rectangular.

[0166] First refer to Figure 15A An example of a field of view relationship between the optical transmitter module TX and the optical detector module RX is shown. Assuming that the first direction is the horizontal direction and the second direction is the vertical direction, the horizontal dimension of the field of view Aa of the optical transmitter module TX is V1. A , the vertical dimension is H1 A , V1 A >H1 A , the horizontal dimension of the field of view Ba of the light detection module RX is V2 A , the vertical dimension is H2 A , and H2 A >V2 A .like Figure 15A As shown, in the horizontal direction, the field of view size V1 of the optical transmitter module TX A Larger than the field of view V2 of the light detection module RX A , that is, V1 A >V2 A ; In the vertical direction, the field of view size H1 of the optical transmitter module TX A Smaller than the field of view size H2 of the light detection module RX A , that is, H1 A <H2 A .

[0167] Then refer to Figure 15B Another example of the field of view relationship between the optical transmitter module TX and the optical detection module RX is shown. Assuming that the first direction is the vertical direction and the second direction is the horizontal direction, the horizontal dimension of the field of view Ab of the optical transmitter module TX is V1 B , the vertical dimension is H1 B , V1 B B , the horizontal dimension of the field of view Bb of the light detection module RX is V2 B , the vertical dimension is H2 B , and H2 B <V2 B .like Figure 15B As shown, in the horizontal direction, the field of view size V1 of the optical transmitter module TX B Smaller than the field of view V2 of the light detection module RX B , that is, V1 B <V2 B ; In the vertical direction, the field of view size H1 of the light emitting module A B > Field of view size H2 of light detection module B B , that is, H1 B >H2 B .

[0168] ​As can be seen from the above example, using the above-mentioned optical transceiver module, the primary energy of the light spot returned by the detection beam emitted by the optical transmitter module TX is distributed over the effective area of ​​the optical detection module RX, forming a near-cross shape. If the light spot of the optical transmitter module TX is larger than the width of the optical detection module RX horizontally, then the light spot of the optical transmitter module TX is smaller than that of the optical detection module RX vertically. If the light spot of the optical transmitter module TX is smaller than the width of the optical detection module RX horizontally, then the light spot of the optical transmitter module TX is smaller than that of the optical detection module RX vertically. In this way, even with optical alignment errors due to optics, structure, patch, and temperature drift, the same overlap area and ranging capability can be maintained, thereby improving alignment accuracy and ensuring the consistency and stability of ranging capability across all transceiver channels.

[0169] By using the above-mentioned laser radar, from the perspective of the light margin effect, the allowable errors of the light emitting module and the light detection module in the first direction and the second direction are consistent, thereby improving the design margin of the light-emitting surface of the light emitting module and the photosensitive surface of the light detection module, thereby improving the light accuracy, and thus ensuring the consistency and stability of the ranging capabilities of each channel.

[0170] In a specific implementation, the fields of view corresponding to each light detection unit and its corresponding light emitting unit can be relatively vertically staggered, and the field of view size of each light emitting unit in the first direction is larger than the field of view size of the corresponding detection unit, and the field of view size in the second direction is smaller than the field of view size of the corresponding detection unit.

[0171] When there are optical, structural, patch, temperature drift and other light alignment errors, by making the fields of view corresponding to each light detection unit and its corresponding light emitting unit perpendicular to each other and satisfying the above-mentioned size correspondence, the point cloud detected by each detection channel, that is, the effective area of ​​each point cloud on the focal plane, or the effective detection angle range of each point cloud of the lidar can maintain the same overlapping area and ranging capability, thereby improving the light alignment accuracy and ensuring the consistency and stability of the ranging capability of each transceiver channel.

[0172] In some embodiments of the present invention, corresponding Figure 9 The light emitting unit AU0 shown in FIG. 1 can be used as shown in FIG. Figure 16 Specifically, the light detection unit RU0 includes two detection blocks and corresponding connection points, namely, the detection block Ra1 and the detection block Ra2, as well as the connection point Rb1 corresponding to the detection block Ra1 and the connection point Rb2 corresponding to the detection block Ra2.

[0173] It is understandable that a detection unit may also include only one detection block. Regardless of how many detection blocks a detection unit includes, one detection block may correspond to one or more light-emitting blocks, or one light-emitting block may correspond to multiple detection blocks.

[0174] In some embodiments of the present invention, the multiple light emitting lines in the light emitting module are arranged in multiple columns along the vertical direction, and the multiple light emitting lines can be at least partially staggered, thereby changing the distribution density of the emitted light beam in the vertical field of view. Correspondingly, the multiple detection units in the light detection module are arranged in multiple columns, and the multiple light detection lines are at least partially staggered, and each light detection line is arranged perpendicularly to the field of view of the corresponding light emitting line. If the light emitting unit includes multiple light emitting blocks, each light emitting block has a detection block whose field of view is perpendicularly staggered with its light emitting block.

[0175] From the perspective of the light margin effect, each light emitting unit and light detection unit has a certain allowable error in both the horizontal and vertical directions, and the allowable errors in these two directions are consistent. Therefore, the overall design margin of the light-emitting surface of the light emitting module and the photosensitive surface of the light detection module can be improved, thereby improving the light accuracy and ensuring the consistency and stability of the ranging capabilities of each channel.

[0176] Moreover, by staggering the distribution of multiple columns of light emitting lines in the light emitting module and the corresponding staggered distribution of multiple columns of light receiving lines in the light detection module, a non-uniform distribution of the line beam in the vertical field of view is achieved, which can improve the vertical resolution of the light emitting module and the laser radar including the light emitting module in the target area, and can increase the density of the laser point cloud obtained by detection at a lower cost.

[0177] In addition, the laser radar in the embodiment of the present invention, both the transmitting end and the receiving end adopt this planar design, so that the two can use a symmetrical optical path, the light efficiency is very high, and the plane support plates for transmission and reception (i.e., the first plane support plate and the second plane support plate) are both perpendicular to the optical axis. When the optical-mechanical structure is slightly deformed due to temperature or stress, especially the warping of the circuit board itself, it will not cause serious changes in the light position, that is, the correspondence between the transmitting and receiving channels is basically stable. In this way, as long as sufficient patch accuracy is guaranteed, the overall light alignment can be achieved, which greatly saves installation time. In addition, the laser itself does not need to be pointed at the center, but only uses a telecentric optical path, that is, a field lens is placed near the focal plane to pull the light path back to the optical axis, which can also improve the patch efficiency of the laser itself. Reference Figure 3A and Figure 3B The figure shows the optical path diagram of the optical transmitter module at the transmitting end.

[0178] To facilitate understanding and implementation by those skilled in the art, the following briefly introduces the distance measurement method corresponding to the above-mentioned laser radar, referring to Figure 19 The flowchart of the laser radar ranging method shown in FIG. 1 may specifically include the following steps:

[0179] S11, respectively controlling the light emitting array to emit light pulses and controlling the light detecting array to receive light reflected by external obstacles.

[0180] The light emitting array and the light detecting array are arranged correspondingly. The light emitting array may include a plurality of light emitting lines, each of which is arranged on a first plane, and each of which includes a plurality of light emitting units, whose light emitting directions are perpendicular to the first plane and are non-uniformly distributed in the vertical direction; the light detecting array may include a plurality of light detecting lines, each of which is arranged on a second plane, and each of which includes a plurality of light detecting units.

[0181] In a specific implementation, in the light emitting array, the light emitting units in at least two light emitting lines may be partially intertwined with each other, forming a non-uniform distribution in the vertical direction; correspondingly, in the light detecting array, the light detecting units in at least two light detecting lines may be partially intertwined with each other, forming a non-uniform distribution in the vertical direction.

[0182] The specific implementation of the light emitting array and the light detecting array can refer to the detailed description of the aforementioned light emitting module and light detecting module embodiments, which will not be described in detail here.

[0183] S12, calculating the position information of the obstacle based on the detection data of the light detection array, and merging the detection data of the light detection array within the entire field of view into one frame and outputting it as a point cloud.

[0184] The full field of view includes the horizontal field of view and the vertical field of view.

[0185] As an optional example, the laser radar can be a horizontally scanning mechanical radar. In the laser radar of the embodiment of the present invention, since the light emitting module includes multiple light emitting lines located in different columns, and the corresponding light detecting module includes multiple light detecting lines located in different columns, to help those skilled in the art better understand how to generate point cloud data, the following first briefly describes the operating principle of a horizontally scanning mechanical radar.

[0186] First, the radar's angular velocity ω = 360° fr, where fr is the rotational frequency. For example, if the rotational frequency of a mechanical radar is 20 Hz, then ω = 7200° / s. The repetitive scanning period T is the minimum time slice required to complete all channel measurements, and all channels are repeatedly scanned within this period. When all channels have the same scanning frequency, or the same horizontal angular resolution HRES, HRES = ω * T.

[0187] Due to the rotational inertia of the mechanical radar, the scanning angular velocity ω can be considered constant within the range of angular resolution. Therefore, the mechanical angle at a certain moment can be predicted using the formula Φ=Φ0+ω*ΔT, where Φ is the mechanical angle at the current light-emitting moment, Φ0 is the mechanical angle at the previous light-emitting moment, and ΔT is the value in the timing table, that is, the time difference between the actual light-emitting moment of the point cloud data and the previous measurement moment.

[0188] In a specific implementation, the laser radar can adopt a method in which all channels emit light simultaneously, or it can also adopt a method in which all channels emit light non-simultaneously (for example, in a patrol manner).

[0189] First refer to Figure 17A The corresponding relationship between the horizontal scanning process and the generated point cloud when the non-patrol light is shown as follows Figure 18A The diagram shows the correspondence between the horizontal scanning process and the generated point cloud during patrol lighting. As an example, the horizontal center distance Gap between two adjacent light emitting line arrays BankA and BankB can be in the order of cm; the horizontal angle between them is x°, which is greater than the horizontal angular resolution. As some optional embodiments, the specific values ​​can be, for example, 3°, 10°, or 12°. The pitch Pitch of the light emitting units in each light emitting line array is in the order of μm. Figure 17A The figure shows the correspondence between the horizontal scanning process and the generated point cloud when all channels are illuminated simultaneously, where the horizontal angles at time t1 are θ i , Φ i , the corresponding point cloud sequence can be scanned separately. After ω*T time, that is, at time t2, the light emitting units in the light emitting line array BankA and BankB emit light again at the same time, and the horizontal angles can be scanned to be θ i+1 , Φ i+1 The point cloud sequence, the horizontal angular resolution corresponding to the two scans at time t1 and t2 is t2-t1=ω*T=HRES.

[0190] Figure 18A The figure shows the corresponding relationship between the horizontal scanning process and the generated point cloud when each channel is patrolling and emitting light. Since each light emitting unit does not emit light at the same time, as shown in Figure 18AAs shown, if the light emitting units in the light emitting line arrays BankA and BankB emit light in sequence from top to bottom, for example, in the Vx direction, from top to bottom, according to the timing, at time t1, the first light emitting unit in the light emitting line arrays BankA and BankB emits light, at time T', the second light emitting unit in the light emitting line arrays BankA and BankB emits light, at time T", the third light emitting unit in the light emitting line arrays BankA and BankB emits light, and at time T'", the fourth light emitting unit in the light emitting line arrays BankA and BankB emits light, then the point cloud corresponding to each light emitting unit in the same light emitting line array has a certain offset in the horizontal direction, as shown in FIG. Figure 18A shown.

[0191] Next, refer to Figure 17B The diagram of the corresponding relationship between the channel and the point cloud of the horizontal scanning mechanical radar when it is not patrolling, and Figure 18B The diagram shows the corresponding relationship between the channel and the point cloud of the horizontal scanning mechanical radar during patrol lighting. The laser radar's light emitting module TX and light detection module are correspondingly arranged. The light emitting module includes light emitting line arrays TL1 to TL4 arranged unevenly in the vertical direction. Each light emitting line array includes multiple light emitting units. Correspondingly, the light detection module RX includes light detection line arrays RL1 to RL4 arranged unevenly in the vertical direction. Each light detection line array includes multiple detection units (e.g., detectors). If the light emitting units (e.g., lasers) in each light emitting line array TL1 to TL4 emit light simultaneously, the corresponding light detection module RX performs detection.

[0192] The light emitting unit (laser) referred to here refers to the smallest addressable unit. For example, if a VCSEL has multiple light-emitting holes that emit light simultaneously, they can only be counted as one light emitting unit. Only when a single laser or a group of lasers can be addressed and selected can they be counted as multiple light emitting units. Similarly, the light detection unit (such as a detector) also refers to the smallest addressable unit. If multiplexing is used, the multiplexed units can be coupled together with wires.

[0193] Continue to refer to Figure 17B , in the middle is the point cloud field of view angle, the horizontal position of each point represents the horizontal angle θ, and the vertical position represents the pitch angle γ, where γ = β. The horizontal angle shifts as the radar rotor rotates, θ = α + ω * (n * T + ΔTi), where ΔTi is the time delay of the i-th channel relative to the previous measurement moment, α is the horizontal angle at the previous measurement moment, and T is the minimum time slice T to complete the full channel scan. In this way, combined with the horizontal angle θ and the pitch angle γ, for non-patrol light emission, a point cloud image of a portion of a frame can be generated (the vertical field of view completely corresponds to the vertical FoV of the radar, and the horizontal field of view only shows the data of 3 scanning time slices T) as shown below. Figure 17BAs shown; for patrol lighting, a point cloud image of a part of a frame is generated as follows Figure 18B As shown in Figure 1, the vertical field of view completely corresponds to the vertical FoV of the radar, and the horizontal field of view only shows the data of 3 scanning time slices T.

[0194] Although the embodiments of the present invention are disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. An optical transmission module, characterized in that: include: a first planar support plate; A plurality of light emitting line arrays constitute a light emitting array and are disposed on the first planar support plate, each light emitting line array comprising a plurality of light emitting units; wherein the light emitting units comprise a plurality of light emitting blocks, the plurality of light emitting blocks share a cathode or anode, and each light emitting block has a connection point, the connection point being electrically connected to the unshared anode or cathode of the corresponding light emitting block; and the field of view of the light emitting block in a first direction is larger than the field of view of the corresponding receiving block in the first direction, and the field of view of the light emitting block in a second direction is smaller than the field of view of the corresponding receiving block in the second direction, and the first direction and the second direction are perpendicular to each other; The light emitting directions of the light emitting units are perpendicular to the first planar support plate, and the light emitting units in at least two light emitting lines are partially staggered with each other, forming a non-uniform distribution in the vertical direction.

2. The optical transmitter module according to claim 1, wherein: The plurality of light emitting lines are arranged such that the density of the light emitting units near the middle region of the first planar support plate in the vertical direction is greater than the density of the light emitting units near the upper and lower sides.

3. The optical transmitter module according to claim 2, wherein: The arrangement density of the plurality of light emitting line arrays in the vertical direction decreases uniformly or gradually from the middle to the upper and lower sides.

4. The optical transmitter module according to claim 2, wherein: The light emitting array is a light emitting unit encrypted area within the vertical field angle range of ±5°.

5. The optical transmitter module according to claim 2, wherein: The plurality of light emitting line columns in the light emitting array are distributed in a plurality of columns, and the light emitting units in different light emitting line columns are located in different rows.

6. The optical transmitter module according to claim 1, wherein: The spacing between the light emitting units in the light emitting line array is the same or unevenly distributed.

7. The optical transmitter module according to claim 1, wherein: The light emitting module is used for laser radar and is arranged at the focal plane position of the transmitting end of the laser radar. It also includes a field lens, which is suitable for converging the light emitted by the light emitting unit to pull the light emitted by the light emitting unit back to the optical axis of the transmitting end.

8. The optical transmission module according to claim 7, wherein: It also includes a lens group suitable for deflecting the light emitted by the light emitting unit so that the light emitted by the lasers that emit light perpendicular to the first planar support plate can cover the entire vertical field of view of the laser radar.

9. The optical transmitter module according to claim 1, wherein: The pitch of the light emission array formed by the plurality of light emission line columns is greater than or equal to the pitch of a single light emission line column divided by the number of staggered columns.

10. The optical transmitter module according to claim 1, wherein: The overlap of the light spots of adjacent light emitting units is slightly smaller than the center distance between two adjacent light emitting units.

11. The optical transmitter module according to claim 1, wherein: The light emitting unit includes at least one of the following: a vertical cavity surface emitting laser, a photonic crystal surface emitting semiconductor laser.

12. The optical transmission module according to any one of claims 1 to 11, characterized in that: The plurality of light emitting line arrays arranged on the first planar support plate have the same specifications or different specifications.

13. A laser radar, characterized in that: include: A light emitting module and a light detection module arranged corresponding to the light emitting module, wherein: The light emitting module is arranged on the focal plane of the emitting end and includes: a first planar support plate; A plurality of light emitting line arrays constitute a light emitting array and are disposed on the first planar support plate, each light emitting line array comprising a plurality of light emitting units; the light emitting directions of the light emitting units are perpendicular to the first planar support plate, and the light emitting units in at least two light emitting line arrays are partially staggered with each other, forming a non-uniform distribution in the vertical direction; The light detection module is arranged on the focal plane of the receiving end and includes: a second planar support plate; A plurality of light detection lines constitute a light detection array, which is disposed on the second planar support plate, wherein each light detection line comprises a plurality of light detection units, and the light detection units in at least two light detection lines are partially staggered with each other to form a non-uniform distribution in the vertical direction; The field of view of the light emitting module in the first direction is larger than the field of view of the light detecting module in the first direction, and the field of view of the light emitting module in the second direction is smaller than the field of view of the light detecting module in the second direction, and the first direction is perpendicular to the second direction.

14. A laser radar ranging method, characterized in that: include: Respectively controlling the light emitting array to emit light pulses and controlling the light detecting array to receive light reflected by external obstacles; wherein: the light emitting array and the light detecting array are arranged correspondingly; the light emitting array includes a plurality of light emitting lines, each of which is arranged on a first plane, and each of which includes a plurality of light emitting units, whose light emitting directions are perpendicular to the first plane and are non-uniformly distributed in the vertical direction; the light detecting array includes a plurality of light detecting lines, each of which is arranged on a second plane, and each of which includes a plurality of light detecting units; the field of view size of the light emitting module in the first direction is larger than the field of view size of the light detecting module in the first direction, and the field of view size of the light emitting module in the second direction is smaller than the field of view size of the light detecting module in the second direction, and the first direction and the second direction are perpendicular; The position information of the obstacle is calculated based on the detection data of the light detection array, and the detection data of the light detection array within the entire field of view is merged into one frame and output as a point cloud.

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