Optical phased array lidar, lidar system and its scanning method

Abstract

This invention relates to the field of lidar scanning technology, and more particularly to an optical phased array lidar, a lidar system, and its scanning method. The scanning method includes: A1: acquiring a two-dimensional grayscale image. A2: performing differential processing on the current frame image and the previous frame image, identifying pixels with non-zero grayscale value changes, generating a change region, and extracting a set of coordinates of the change points. A3: based on the set of coordinates of the change points, mapping the coordinates of each change point to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scanning lookup table, thereby generating a set of control parameters. A4: according to the set of scanning control parameters, controlling the optical phased array lidar to scan the change region sequentially, generating point cloud data. The advantage of this invention is that by identifying the grayscale value changes between two adjacent frames and completing the autonomously guided OPA lidar scanning, redundant data is reduced, and the complexity of subsequent data processing is lowered.

Description

Technical Field

[0001] This invention relates to the field of lidar scanning technology, and in particular to an optical phased array lidar, a lidar system and its scanning method. Background Technology

[0002] Optical phased array (OPA) is a beam pointing technology that dynamically controls the direction, shape, and intensity of a beam by manipulating its phase. OPA lidar, with an OPA chip at its core, integrates laser ranging and imaging technologies. Its phase control primarily relies on two modulation methods: electro-optic and thermo-optic. Electro-optic modulation changes the carrier concentration and refractive index by applying a voltage to the PN junction of the waveguide; thermo-optic modulation achieves phase control by adjusting the temperature through a driving voltage.

[0003] In two-dimensional scanning, the OPA lidar controls the lateral scanning phase angle by driving voltage and simultaneously changes the laser wavelength to achieve longitudinal scanning, thereby covering the entire two-dimensional scene.

[0004] However, the performance of existing OPA LiDARs is limited by their low scanning speed. The bottleneck mainly stems from the limitations of control word writing and configuration speed, as well as voltage settling speed. When multiple OPA LiDARs perform global 2D scene scanning, the slow scanning speed results in a low frame rate for the generated 3D images, making it difficult to meet the requirements of high-speed 3D point cloud data acquisition. Furthermore, in applications such as vehicle-mounted road detection, the system still needs to perform global scanning of non-critical areas such as the sky and road surface, resulting in wasted hardware resources and redundant data, further slowing down the frame rate.

[0005] On the other hand, the photodetector of OPA lidar needs to use a filter to filter the incident light to ensure that only echoes in the same spectral band as the emitted laser are detected and to improve the signal-to-noise ratio. However, narrowband filtering weakens the echo intensity, and the waveguide array introduces light intensity attenuation in the outgoing and return paths, resulting in a decrease in system optical efficiency and affecting detection performance. Summary of the Invention

[0006] Based on this, the present invention proposes an optical phased array lidar, a lidar system, and a scanning method thereof. By identifying the differences between two adjacent frames of two-dimensional phased array images, the changing regions in the scene under test are identified, thereby guiding the OPA lidar to focus on scanning the changing regions.

[0007] To achieve the above objectives, the technical solution of this invention is implemented as follows: An optical phased array lidar includes: a laser for emitting a laser beam to scan objects in a scene; an optical phased array for controlling the laser beam through phase control to change the direction and shape of the laser beam; a planar photodetector for acquiring a two-dimensional grayscale image of the scene; an image processing module for performing differential processing on two adjacent frames of the two-dimensional grayscale image, identifying pixels with non-zero grayscale values ​​as change points, generating change regions, and extracting a set of coordinates of the change points; a data processing module for mapping the coordinates of the change points to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to a pre-set scan lookup table, generating a set of control parameters consisting of the driving voltage value and the emission wavelength value; and a control module for controlling the optical phased array lidar to scan the change regions according to the set of control parameters to obtain point cloud data.

[0008] A scanning method based on an event mechanism, implemented using the aforementioned optical phased array lidar, includes the following steps:

[0009] A1: Retrieve a 2D grayscale image of the scene.

[0010] A2: Identify pixels whose grayscale values ​​change between two adjacent frames as change points, generate change regions, and extract the set of coordinates of the change points.

[0011] A3: Based on the set of coordinates of the changing points, the coordinates of each changing point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scanning lookup table, thereby generating a set of control parameters.

[0012] A4: Based on the set of scanning control parameters, control the optical phased array lidar to scan the changing area sequentially and generate point cloud data.

[0013] Furthermore, the pre-set scan lookup table in step A3 includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral scan lookup table and the longitudinal scan lookup table are used to obtain the corresponding driving voltage value and laser wavelength value according to the coordinate mapping of the pixel during the scanning process.

[0014] An optical phased array lidar system based on an area array camera includes: a beam splitting system configured to separate an incident light beam from a scene into a reflected beam and a transmitted beam; an area array camera used to receive the reflected beam and acquire a two-dimensional grayscale image of the scene; and an optical phased array lidar system including: a laser, an optical phased array, a filter, a lidar detector, an image processing module, a data processing module, and a control module; the laser is used to emit a laser beam to scan objects in the scene; the optical phased array is used to control the laser beam through phase control to change the direction and shape of the laser beam; and a filter is used to set... In the optical path of the transmitted beam; the lidar detector is used to receive the beam after it has been filtered by the filter; the image processing module is used to perform differential processing on two adjacent frames of the two-dimensional grayscale image, identify pixels with non-zero grayscale values ​​as change points, generate change regions, and extract the set of coordinates of change points; the data processing module is used to map the coordinates of change points to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to a pre-set scan lookup table, and generate a set of control parameters consisting of the driving voltage value and the emission wavelength value; the control module is used to control the optical phased array lidar to scan the change region according to the set of control parameters to obtain point cloud data.

[0015] A scanning method based on an event mechanism, implemented using the aforementioned optical phased array lidar system based on a planar array camera, includes the following steps:

[0016] B1: The beam splitting system separates the incident beam from the scene into a reflected beam and a transmitted beam.

[0017] B2: The area array camera receives the reflected light beam and acquires a two-dimensional grayscale image of the scene.

[0018] B3: Identify pixels whose grayscale values ​​change between two adjacent frames as change points, generate change regions, and extract the set of coordinates of change points.

[0019] B4: Based on the set of coordinates of the changing points, the coordinates of each changing point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scan lookup table, thereby generating a set of control parameters.

[0020] B5: Based on the set of scanning control parameters, control the optical phased array lidar to scan the changing area sequentially and generate point cloud data.

[0021] Furthermore, the pre-set scan lookup table in step B4 includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral scan lookup table and the longitudinal scan lookup table are used to obtain the corresponding driving voltage value and laser wavelength value according to the coordinate mapping of the pixel during the scanning process.

[0022] An optical phased array lidar system based on an event camera includes: a beam splitting system configured to separate an incident beam from a scene into a reflected beam and a transmitted beam; an event camera used to receive the reflected beam, acquire the coordinates of pixels that have changed in the scene, generate a change region, and extract a set of coordinates of the changed points; and an optical phased array lidar including: a laser, an optical phased array, a filter, a lidar detector, a data processing module, and a control module; the laser is used to emit a laser beam to scan objects in the scene; the optical phased array is used to control the laser beam through phase control to change the direction and shape of the laser beam; the filter is placed in the optical path of the transmitted beam; the lidar detector is used to receive the beam filtered by the filter; the data processing module is used to map the coordinates of the changed points to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to a pre-set scan lookup table, generating a set of control parameters consisting of the driving voltage value and the emission wavelength value; and the control module is used to control the optical phased array lidar to scan the change region according to the set of control parameters to obtain point cloud data.

[0023] An event-triggered scanning method includes the following steps:

[0024] C1: The beam splitting system separates the incident beam from the scene into a reflected beam and a transmitted beam.

[0025] C2: The event camera receives the reflected light beam, acquires the coordinates of pixels that have changed in the scene, generates the changed area, and extracts the set of coordinates of the changed points.

[0026] C3: Based on the set of coordinates of the changing points, the coordinates of each changing point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scan lookup table, thereby generating a set of control parameters.

[0027] C4: Based on the set of scanning control parameters, control the optical phased array lidar to scan the changing area sequentially and generate point cloud data.

[0028] Furthermore, the pre-set scan lookup table in step C3 includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral scan lookup table and the longitudinal scan lookup table are used to obtain the corresponding driving voltage value and laser wavelength value according to the coordinate mapping of the pixel during the scanning process.

[0029] The present invention can achieve the following beneficial effects: by identifying the changes in grayscale values ​​between two adjacent frames of images and completing the autonomously guided OPA lidar scanning imaging mode, redundant data is reduced and the complexity of subsequent data processing is lowered.

[0030] By setting up a beam splitting system, visible surface array cameras or event cameras can use strong ambient light to perform surface array imaging of the scene under test, effectively improving the accuracy of image recognition.

[0031] This method optimizes resource allocation, focusing limited detection capabilities on identifying changes in grayscale values ​​between adjacent image frames. This significantly improves the detection speed of local scanning and the system's response speed to targets, ultimately generating more salient and higher-quality 3D point clouds. Furthermore, this method reduces redundant data and lowers the complexity of subsequent data processing, providing technical support for achieving higher performance and energy efficiency in optical phased array lidar scanning imaging. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the structure of an optical phased array lidar system based on a planar array camera according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of an optical phased array lidar system based on an event camera according to an embodiment of the present invention;

[0035] Figure 3 This is a flowchart of an event-triggered scanning method implemented using an optical phased array lidar according to an embodiment of the present invention;

[0036] Figure 4 This is a flowchart of an event-triggered scanning method implemented using an optical phased array lidar system based on a planar array camera, according to an embodiment of the present invention.

[0037] Figure 5 This is a flowchart of an event-triggered scanning method implemented using an event-based camera optical phased array lidar system, according to an embodiment of the present invention.

[0038] Figure 6 It is provided according to the embodiments of the present invention. Figure 3 and Figure 4 Example diagram showing the scanning process completed by the scanning method. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The invention will now be described in detail with reference to specific embodiments.

[0044] like Figures 1 to 6 As shown in the figure, an optical phased array lidar provided by an embodiment of the present invention includes: a laser, an optical phased array, a surface array photodetector, an image processing module, a data processing module, and a control module.

[0045] The laser emits a laser beam to scan objects in the scene. An optical phased array controls the laser beam's direction and shape through phase control. A photodetector array acquires a two-dimensional grayscale image of the scene. The image processing module performs differential processing on adjacent frames of the grayscale image, identifying pixels with non-zero grayscale values ​​as change points, generating change regions, and extracting a set of coordinates for these change points. The data processing module maps the change point coordinates to the optical phased array's driving voltage and the laser's emission wavelength using a pre-set scan lookup table, generating a set of control parameters consisting of these values. The control module, based on these control parameters, controls the optical phased array lidar to scan the change regions, obtaining point cloud data.

[0046] A scanning method based on an event mechanism, implemented using the aforementioned optical phased array lidar, includes the following steps:

[0047] A1: The area array photodetector captures a two-dimensional grayscale image of the scene.

[0048] A2: Identify pixels whose grayscale values ​​change between two adjacent frames as change points, generate change regions, and extract the set of coordinates of the change points.

[0049] Specifically, the image processing module subtracts the first frame from the second frame. For the resulting 2D grayscale image, if the grayscale value of a pixel is not zero, then that pixel is the point of change between the two frames. The coordinates of all points of change are obtained in this way, generating a change region and extracting the set of coordinates of the points of change. Then, proceed to the next step.

[0050] If, after subtraction, all pixels in the 2D grayscale image have a grayscale value of zero, it means there is no change between the first and second frames. The process continues by acquiring the third frame, and then subtracting from the second and third frames. For the subtracted 2D image, if a pixel has a non-zero grayscale value, that pixel is the point of change between the two frames. The coordinates of all points of change are obtained in this way, forming the set of coordinates. Proceed to the next step. If, after subtraction, all pixels in the 2D grayscale image have a grayscale value of zero, it means there is no change between the second and third frames. The process continues by acquiring the fourth 2D area image, and so on, until the points of change are obtained.

[0051] A3: Based on the set of coordinates of the changing points, the coordinates of each changing point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scanning lookup table, thereby generating a set of control parameters.

[0052] The pre-set scan lookup table includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral scan lookup table and the longitudinal scan lookup table are used to obtain the corresponding driving voltage value and laser wavelength value according to the coordinate mapping of the pixel during the scanning process.

[0053] The coordinates of each pixel are (x1, y1), (x2, y2), ..., (x...). Mi y Mi The control parameter set (V1, λ1), (V2, λ2), ..., (V2, λ2) corresponding to the driving voltage value and the emission wavelength value for each point is mapped through horizontal and vertical scan lookup tables. Mi , λ ri ), ri is the number of rows of the points to be measured in the scanning area Ri, corresponding to ri scanning wavelengths.

[0054] A4: Based on the set of scanning control parameters, control the optical phased array lidar to scan the changing area sequentially and generate point cloud data.

[0055] Specifically, the control module sets the emission wavelength of the laser and the driving voltage of the optical phased array based on the set of control parameters, and controls the optical phased array lidar to scan all the test points in the region of interest line by line.

[0056] Adjust the emission wavelength of the laser to λ1, where λ1 is the scanning wavelength corresponding to the first row of pixels in the changing region; according to the driving voltage value obtained in step A3, control the OPA to complete the scanning of the first row of test points in the scanning region R1.

[0057] Adjust the laser emission wavelength to λ2, ..., λ r1 Where r1 is the number of rows of test points in the changing region, corresponding to r1 scanning wavelengths. Repeat the above process until all test points in the scanning region R1 are measured.

[0058] A5: Iterate through steps A1 to A4 to continuously generate 3D point cloud data of the region of interest.

[0059] An optical phased array lidar system based on an area array camera includes: a beam splitting system, an area array camera, and an optical phased array lidar.

[0060] The beam splitting system is configured to separate the incident light beam from the scene into a reflected beam and a transmitted beam. An area array camera receives the reflected beam and acquires a two-dimensional grayscale image of the scene. The optical phased array lidar includes: a laser, an optical phased array, filters, a lidar detector, an image processing module, a data processing module, and a control module. The laser emits a laser beam to scan objects in the scene. The optical phased array controls the laser beam through phase control to change its direction and shape. Filters are placed in the optical path of the transmitted beam. The lidar detector receives the beam filtered by the filters. The image processing module performs differential processing on adjacent frames of the two-dimensional grayscale image, identifies pixels with non-zero grayscale values ​​as change points, generates change regions, and extracts a set of coordinates for these change points. The data processing module maps the coordinates of these change points to the driving voltage value of the optical phased array and the emission wavelength value of the laser, generating a set of control parameters consisting of the driving voltage value and the emission wavelength value, based on a pre-set scan lookup table. The control module is used to control the optical phased array lidar to scan the changing area according to the set of control parameters, so as to obtain point cloud data.

[0061] A scanning method based on an event mechanism, implemented using the aforementioned optical phased array lidar system based on a planar array camera, includes the following steps:

[0062] B1: The beam splitting system separates the incident light beam from the scene into a reflected beam and a transmitted beam. The reflected beam is received by the area array camera, while the transmitted beam is received by the lidar detector after passing through a filter.

[0063] B2: The area array camera receives the reflected light beam and acquires a two-dimensional grayscale image of the scene.

[0064] B3: Identify pixels whose grayscale values ​​change between two adjacent frames as change points, generate change regions, and extract the set of coordinates of change points.

[0065] Specifically, the image processing module subtracts the first frame (previous frame) from the second frame (current frame). For the resulting 2D grayscale image, if the grayscale value of a pixel is not zero, then that pixel is the point of change between the two frames. The coordinates of all points of change are obtained in this way, generating a change region and extracting the set of coordinates of the points of change. Then, proceed to the next step.

[0066] If, after subtraction, all pixels in the 2D grayscale image have a grayscale value of zero, it means there is no change between the first and second frames. The process continues by acquiring the third frame, and then subtracting from the second and third frames. For the subtracted 2D image, if a pixel has a non-zero grayscale value, that pixel is the point of change between the two frames. The coordinates of all points of change are obtained in this way, forming the set of coordinates. Proceed to the next step. If, after subtraction, all pixels in the 2D grayscale image have a grayscale value of zero, it means there is no change between the second and third frames. The process continues by acquiring the fourth 2D area image, and so on, until the points of change are obtained.

[0067] B4: Based on the set of coordinates of the changing points, the coordinates of each changing point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scan lookup table, thereby generating a set of control parameters.

[0068] The pre-set scan lookup table includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral scan lookup table and the longitudinal scan lookup table are used to obtain the corresponding driving voltage value and laser wavelength value according to the coordinate mapping of the pixel during the scanning process.

[0069] The coordinates of each pixel are (x1, y1), (x2, y2), ..., (x...). Mi y Mi The control parameter set (V1, λ1), (V2, λ2), ..., (V2, λ2) corresponding to the driving voltage value and the emission wavelength value for each point is mapped through horizontal and vertical scan lookup tables. Mi , λ ri ), ri is the number of rows of the points to be measured in the scanning area Ri, corresponding to ri scanning wavelengths.

[0070] B5: Based on the set of scanning control parameters, control the optical phased array lidar to scan the changing area sequentially and generate point cloud data.

[0071] Specifically, the control module sets the emission wavelength of the laser and the driving voltage of the optical phased array based on the set of control parameters, and controls the optical phased array lidar to scan all the test points in the region of interest line by line.

[0072] Adjust the emission wavelength of the laser to λ1, where λ1 is the scanning wavelength corresponding to the first row of pixels in the changing region; according to the driving voltage value obtained in step B4, control the OPA to complete the scanning of the first row of test points in the scanning region R1.

[0073] Adjust the laser emission wavelength to λ2, ..., λ r1 Where r1 is the number of rows of test points in the changing region, corresponding to r1 scanning wavelengths. Repeat the above process until all test points in the scanning region R1 are measured.

[0074] B6: Iterate through steps B1 to B5 to continuously generate 3D point cloud data of the region of interest.

[0075] An optical phased array lidar system based on an event camera includes: a beam splitting system, an event camera, and an optical phased array lidar.

[0076] The beam splitting system is configured to separate the incident light beam from the scene into a reflected beam and a transmitted beam. An event camera receives the reflected beam, acquires the coordinates of pixels that change in the scene, generates a change region, and extracts a set of coordinates for the changed points. The optical phased array lidar includes: a laser, an optical phased array, filters, a lidar detector, a data processing module, and a control module. The laser emits a laser beam to scan objects in the scene. The optical phased array controls the laser beam through phase control to change its direction and shape. Filters are placed in the optical path of the transmitted beam. The lidar detector receives the beam filtered by the filters. The data processing module maps the coordinates of the changed points to the driving voltage value of the optical phased array and the emission wavelength value of the laser, generating a set of control parameters consisting of the driving voltage value and the emission wavelength value, based on a pre-set scan lookup table. The control module controls the optical phased array lidar to scan the change region according to the control parameter set, obtaining point cloud data.

[0077] An event-triggered scanning method includes the following steps:

[0078] C1: The beam splitting system separates the incident light beam from the scene into a reflected beam and a transmitted beam. The reflected beam is received by the event camera, while the transmitted beam is received by the lidar detector after passing through a filter.

[0079] C2: The event camera receives the reflected light beam, acquires the coordinates of pixels that have changed in the scene, generates the change area, and extracts the set of coordinates of the change points.

[0080] It should be noted that if the event camera does not detect any changed pixels in the scene, the event camera will continue to monitor until it acquires a changed pixel and proceeds to the next step.

[0081] C3: Based on the set of coordinates of the changing points, the coordinates of each changing point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scan lookup table, thereby generating a set of control parameters.

[0082] The pre-set scan lookup table in step C3 includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral and longitudinal scan lookup tables are used to obtain the corresponding driving voltage value and laser wavelength value based on the coordinate mapping of the pixel during the scanning process. The specific content is the same as steps A3 and B4, and will not be repeated here.

[0083] C4: Based on the set of scanning control parameters, control the optical phased array lidar to scan the changing area sequentially, generating point cloud data. The specific details are the same as steps A4 and B5, and will not be repeated here.

[0084] C5: Iterate through steps C1 to C4 to continuously generate 3D point cloud data of the region of interest.

[0085] In summary, the scanning method of this invention completes autonomously guided OPA lidar scanning imaging by identifying changes in grayscale values ​​between two adjacent image frames. This reduces redundant data and lowers the complexity of subsequent data processing.

[0086] By setting up a beam splitting system, visible surface array cameras or event cameras can use strong ambient light to perform surface array imaging of the scene under test, effectively improving the accuracy of image recognition.

[0087] This method optimizes resource allocation, focusing limited detection capabilities on identifying changes in grayscale values ​​between adjacent image frames. This significantly improves the detection speed of local scanning and the system's response speed to targets, ultimately generating more salient and higher-quality 3D point clouds. Furthermore, this method reduces redundant data and lowers the complexity of subsequent data processing, providing technical support for achieving higher performance and energy efficiency in optical phased array lidar scanning imaging.

[0088] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An optical phased array lidar, comprising: The application relates to a kind of optical phased array lidar, comprising: A laser for emitting a laser beam to scan objects in a scene; An optical phased array for controlling the laser beam by phase control to change the direction and shape of the laser beam; A two-dimensional gray scale image of the scene is obtained by a two-dimensional array photoelectric detector; An image processing module for differentiating adjacent two frames of the two-dimensional gray scale image, identifying pixel points with non-zero gray scale values as change points, generating a change region and extracting a change point coordinate set; A data processing module for mapping the change point coordinates to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to a pre-set scanning lookup table, and generating a control parameter set composed of the driving voltage value and the emission wavelength value; A control module for controlling the optical phased array lidar to scan the change region according to the control parameter set, and obtaining point cloud data.

2. A method for event-triggered scanning, implemented by the optical phased array lidar of claim 1, characterized in that, The application relates to a kind of optical phased array lidar, comprising: A1: obtaining a two-dimensional gray scale image of a scene; A2: identifying pixel points with changed gray scale values in adjacent two frames of the image as change points, generating a change region and extracting a change point coordinate set; A3: mapping the coordinates of each change point to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to a pre-set scanning lookup table based on the change point coordinate set, and further generating a control parameter set; A4: controlling the optical phased array lidar to sequentially scan the change region according to the control parameter set, and generating point cloud data.

3. The method of claim 2, wherein, The pre-set scanning lookup table in step A3 comprises the following steps: Driving the optical phased array lidar to scan within a global field of view, recording the transverse angle of each scanning phase angle and the driving voltage value corresponding to the transverse angle, and establishing a transverse scanning lookup table; Recording the longitudinal angle of each scanning phase angle and the laser emission wavelength value corresponding to the longitudinal angle, and establishing a longitudinal scanning lookup table; The transverse scanning lookup table and the longitudinal scanning lookup table are used to map the corresponding driving voltage value and laser wavelength value according to the coordinates of the pixel points during scanning.

4. An optical phased array lidar system based on an area array camera, characterized by, The application relates to a kind of optical phased array lidar, comprising: A light splitting system configured to separate an incident light beam from a scene into a reflected light beam and a transmitted light beam; A two-dimensional gray scale image of the scene is obtained by a two-dimensional array photoelectric detector; An optical phased array lidar, comprising: a laser, an optical phased array, a filter, a laser radar detector, an image processing module, a data processing module and a control module; The laser is used to emit a laser beam to scan objects in a scene; The optical phased array is used to control the laser beam by phase control to change the direction and shape of the laser beam; The filter is arranged in the light path of the transmitted light beam; The laser radar detector is used to receive the light beam filtered by the filter; An image processing module for differentiating adjacent two frames of the two-dimensional gray scale image, identifying pixel points with non-zero gray scale values as change points, generating a change region and extracting a change point coordinate set; The data processing module is configured to map the coordinates of the change points to driving voltage values of the optical phased array and emission wavelength values of the laser according to a pre-set scanning lookup table, and generate a control parameter set composed of the driving voltage values and the emission wavelength values. The control module is configured to control the optical phased array lidar to scan the change region according to the control parameter set, and obtain point cloud data.

5. A method of event mechanism triggered scanning, implemented by the optical phased array lidar system based on area array camera of claim 4, characterized in that, The method comprises the following steps: B1: The light splitting system separates the incident light beam from the scene into a reflected light beam and a transmitted light beam; B2: The area array camera receives the reflected light beam and acquires a two-dimensional grayscale image of the scene; B3: The gray value of the adjacent two frames of images is identified as a change point, and a change region is generated and a change point coordinate set is extracted; B4: Based on the change point coordinate set, the coordinates of each change point are mapped to the driving voltage values of the optical phased array and the emission wavelength values of the laser through a pre-set scanning lookup table, and then a control parameter set is generated; B5: According to the control parameter set, the optical phased array lidar is controlled to scan the change region in turn, and point cloud data is generated.

6. The method of claim 5, wherein, The pre-set scanning lookup table in step B4 comprises the following steps: Drive the optical phased array lidar to scan within the global field of view, record the transverse angle of each scanning phase angle and the driving voltage value corresponding to the transverse angle, and establish a transverse scanning lookup table; Record the longitudinal angle of each scanning phase angle and the laser emission wavelength value corresponding to the longitudinal angle, and establish a longitudinal scanning lookup table; Wherein, the transverse scanning lookup table and the longitudinal scanning lookup table are used to map the corresponding driving voltage value and laser wavelength value according to the coordinates of the pixel points in the scanning process.

7. An event camera based optical phased array lidar system, comprising: It comprises: A light splitting system configured to separate the incident light beam from the scene into a reflected light beam and a transmitted light beam; An event camera, the event camera is used for receiving the reflected light beam, the event camera acquires the coordinates of the pixel points that change in the scene, generates a change region and extracts a change point coordinate set; An optical phased array lidar, the optical phased array lidar comprises: a laser, an optical phased array, a filter, a laser radar detector, a data processing module and a control module; The laser is used for emitting a laser beam to scan the object of the scene; The optical phased array is used for controlling the laser beam by phase control to change the direction and shape of the laser beam; The filter is arranged in the light path of the transmitted light beam; The laser radar detector is used for receiving the light beam filtered by the filter; The data processing module is configured to map the coordinates of the change points to driving voltage values of the optical phased array and emission wavelength values of the laser according to a pre-set scanning lookup table, and generate a control parameter set composed of the driving voltage values and the emission wavelength values. The control module is configured to control the optical phased array lidar to scan the change region according to the control parameter set, and obtain point cloud data.

8. A method of event mechanism triggered scanning, implemented using the event camera based optical phased array lidar system of claim 7, characterized in that, The method comprises the following steps: C1: The light splitting system separates the incident light beam from the scene into a reflected light beam and a transmitted light beam; C2: the event camera receives the reflected light beam, acquires the coordinates of the changed pixel points in the scene, generates a changed area and extracts a changed point coordinate set; C3: based on the changed point coordinate set, each coordinate of the changed point is mapped to a driving voltage value of the optical phased array and a transmission wavelength value of the laser through a pre-set scanning lookup table, and then a control parameter set is generated; C4: according to the control parameter set, the optical phased array lidar is controlled to scan the changed area in turn, and point cloud data is generated.

9. The event mechanism based trigger scanning method of claim 8, wherein, The pre-set scanning lookup table in step C3 includes the following steps: drive the optical phased array lidar to scan within the global field of view, record the transverse angle of each scanning phase angle and the driving voltage value corresponding to the transverse angle, and establish a transverse scanning lookup table; record the longitudinal angle of each scanning phase angle and the laser transmission wavelength value corresponding to the longitudinal angle, and establish a longitudinal scanning lookup table; wherein the transverse scanning lookup table and the longitudinal scanning lookup table are used to map the corresponding driving voltage value and laser wavelength value according to the coordinates of the pixel points during the scanning process.

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