Lidar system, scanning method thereof, terminal device and computer storage medium

Abstract

The application discloses a laser radar system, a scanning method of the laser radar system, a terminal device and a computer storage medium, and relates to the technical field of laser radar systems. The laser radar system comprises a laser, a scanning mirror, a 4f system, a prism array and a spatial light modulator; the scanning mirror is located on the front focal plane of a first lens in the 4f system, the spatial light modulator is located on the rear focal plane of a second lens in the 4f system, and the prism array is located on the coincident focal plane between the first lens and the second lens; the scanning mirror sequentially projects the scanning light beams output by the laser onto the phase modulation plane of the spatial light modulator after angle deflection to realize scanning imaging. The application can realize coarse scanning on the whole field of view of the scanning mirror and fine scanning on each sub field of view divided by the scanning mirror, so that the scanning efficiency of the phased array laser radar is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to a lidar system, a lidar system scanning method, a terminal device, and a computer storage medium. Background Technology

[0002] Currently, LiDAR, with its advantages of long detection range, high resolution, and low susceptibility to environmental interference, has been widely used in many fields such as intelligent robots, drones, and autonomous vehicles.

[0003] Because spatial light modulators have limited refresh rates and small fields of view, although adding galvanometers can effectively expand the field of view, simply combining a spatial light modulator with a galvanometer cannot improve the imaging speed of phased array lidar under large field-of-view conditions due to the limited refresh rate of the spatial light modulator. Furthermore, to ensure that the beam movement caused by galvanometer oscillation remains within the phase modulation plane of the spatial light modulator, the phase modulation area of ​​the spatial light modulator needs to be set sufficiently large. This results in a significant waste of pixels in the spatial light modulator of existing phased array lidars. Summary of the Invention

[0004] The main objective of this invention is to provide a lidar system, a lidar system scanning method, a terminal device, and a computer storage medium, aiming to expand the field of view of phased array lidar based on spatial light modulators and make full use of the number of pixels of spatial light modulators to avoid pixel waste, and to segment the field of view to achieve simultaneous coarse and fine scanning of the entire field of view of the scanning mirror, thereby effectively improving the scanning efficiency of phased array lidar.

[0005] On the one hand, to achieve the above objectives, the present invention provides a lidar system, the lidar system comprising: a laser, a scanning mirror, a 4f system, a prism array, and a spatial light modulator;

[0006] The scanning mirror is located on the front focal plane of the first lens in the 4f system, the spatial light modulator is located on the rear focal plane of the second lens in the 4f system, and the prism array is located on the overlapping focal plane between the first lens and the second lens;

[0007] The scanning mirror deflects the scanning beam output by the laser at an angle, and then projects it sequentially through the first lens, the prism array, and the second lens onto the phase modulation plane of the spatial light modulator for scanning imaging.

[0008] In one feasible embodiment, the lidar system further includes a polarizer located between the laser and the scanning mirror;

[0009] The scanning beam output by the laser is converted into linearly polarized light by the polarizer, and the scanning mirror deflects the linearly polarized scanning beam at an angle.

[0010] In one feasible embodiment, the lidar system further includes a collimating lens located between the laser and the polarizer;

[0011] The scanning beam output by the laser is collimated by the collimating lens and then becomes linearly polarized light by the polarizer.

[0012] On the other hand, to achieve the above objectives, the present invention also provides a scanning method for a lidar system, wherein the scanning method for the lidar system is applied to the lidar system described above, and the scanning method for the lidar system includes:

[0013] The scanning beam reflected by the scanning mirror is stably projected onto the phase modulation plane of the spatial light modulator through the 4f system to form the complete field of view of the scanning mirror;

[0014] The prism array is used to deflect the scanning beam passing through the 4f system to divide the complete field of view into individual segmented fields of view.

[0015] Scanning is performed on the complete field of view and / or each of the segmented fields of view.

[0016] In one feasible embodiment, the step of scanning the complete field of view and / or each of the segmented fields of view includes:

[0017] The scanning mirror traverses the entire field of view to perform a coarse scan of the entire field of view;

[0018] And / or,

[0019] The spatial light modulator performs independent fine scanning of each of the segmented fields of view.

[0020] In one feasible embodiment, the lidar system further includes a polarizer, prior to the scanning beam reflected by the scanning mirror through the 4f system; the method further includes:

[0021] The polarizer processes the scanning beam into linearly polarized light.

[0022] The scanning beam is reflected by the scanning mirror to become linearly polarized light.

[0023] In one feasible embodiment, the lidar system further includes a collimating lens, and the method further includes, prior to processing the scanning beam into linearly polarized light through the polarizer:

[0024] The scanning beam is collimated using the collimating lens;

[0025] The process of converting the scanning beam into linearly polarized light using the polarizer includes:

[0026] The collimated scanning beam is passed through the polarizer to process it into linearly polarized light.

[0027] In one feasible embodiment, the method further includes:

[0028] The scanning mirror is controlled to swing to adjust the field of view of the complete field of view.

[0029] Furthermore, to achieve the above objectives, the present invention also provides a scanning device for a lidar system, the device being applied to the lidar system described above, the device comprising:

[0030] The light control module is used to stably project the scanning beam reflected by the scanning mirror through the 4f system onto the phase modulation plane of the spatial light modulator to form the complete field of view of the scanning mirror;

[0031] The field of view segmentation module is used to deflect the scanning beam passing through the 4f system using the prism array to segment the complete field of view into individual segmented fields of view.

[0032] A field-of-view scanning module is used to scan the complete field of view and / or each of the segmented fields of view.

[0033] Each functional module of the scanning device of the lidar system of the present invention implements the scanning method of the lidar system as described above during operation.

[0034] In addition, to achieve the above objectives, the present invention also provides a terminal device, the terminal device comprising: a memory, a processor, and a scanning program for a lidar system stored in the memory and executable on the processor, wherein the scanning program for the lidar system, when executed by the processor, implements the steps of the scanning method for the lidar system as described above.

[0035] Furthermore, to achieve the above objectives, the present invention also proposes a computer storage medium storing a scanning program for a lidar system, wherein the scanning program for the lidar system, when executed by a processor, implements the steps of the scanning method for the lidar system as described above.

[0036] In this embodiment of the invention, by employing a prism array and a 4f system in the phased array lidar, a scanning mirror is placed on the front focal plane of the first lens in the 4f system, and a spatial light modulator is placed on the rear focal plane of the second lens in the 4f system. The prism array is placed on the coincident focal plane between the first lens and the second lens. Thus, the scanning mirror can deflect the scanning beam output by the laser and project it onto the phase modulation plane of the spatial light modulator after passing through the first lens, the prism array and the second lens in sequence for scanning imaging.

[0037] Thus, this invention expands the field of view of the phased array lidar based on the spatial light modulator by oscillating the scanning mirror in the phased array lidar to adjust the deflection angle of the scanning beam. Furthermore, a prism array deflects the scanning beam so that the scanning spot emitted from the scanning mirror falls at different positions on the phase modulation plane of the spatial light modulator, thereby fully utilizing the pixel count of the spatial light modulator for field scanning and effectively avoiding pixel waste. Moreover, this invention segments the scanning field of view by deflecting light rays at different angles within the entire field of view of the scanning mirror using a prism array. Different positions on the phase modulation plane of the spatial light modulator can perform fine scanning of sub-fields of view. Therefore, the system can simultaneously perform coarse and fine scanning of the entire field of view of the scanning mirror, effectively improving the scanning efficiency of the phased array lidar.

[0038] Furthermore, by employing a 4f system, this invention ensures the stability of the scanning beam on the spatial light modulator, eliminating the need for the spatial light modulator's phase modulation pattern to be updated as the light spot moves. This reduces the requirements for the update speed of the spatial light modulator, thus freeing the phased array lidar from the limitation of the spatial light modulator's imaging speed. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall architecture of an embodiment of the lidar system of the present invention;

[0040] Figure 2 This is a schematic diagram of the architecture of a radar system according to an embodiment of the lidar system of the present invention;

[0041] Figure 3 This is a schematic diagram of the architecture of another radar system according to an embodiment of the lidar system of the present invention;

[0042] Figure 4 This is a schematic diagram of the application process of an embodiment of the lidar system of the present invention;

[0043] Figure 5 This is a schematic diagram of the hardware operating environment involved in the embodiments of the present invention;

[0044] Figure 6 This is a schematic flowchart illustrating an embodiment of the scanning method of the lidar system of the present invention;

[0045] Figure 7 This is a schematic diagram of the functional modules involved in an embodiment of the scanning device of the lidar system of the present invention.

[0046] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0047] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0048] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the overall architecture of the lidar system of the present invention.

[0049] The lidar system of this invention is a phased array lidar system combining a scanning mirror and a spatial light modulator. The lidar system of this invention includes:

[0050] Lasers, scanning mirrors, 4F systems, prism arrays, and spatial light modulators;

[0051] The scanning mirror is located on the front focal plane of the first lens in the 4f system, the spatial light modulator is located on the rear focal plane of the second lens in the 4f system, and the prism array is located on the overlapping focal plane between the first lens and the second lens;

[0052] The scanning mirror deflects the scanning beam output by the laser at an angle, and then projects it sequentially through the first lens, the prism array, and the second lens onto the phase modulation plane of the spatial light modulator for scanning imaging.

[0053] like Figure 1 As shown, in this embodiment, the lidar system of the present invention includes a laser that outputs a scanning beam, a scanning mirror that deflects the scanning beam output by the laser, a 4f system composed of a first lens (lens 1 in the figure) and a second lens (lens 2 in the figure), a prism array, and a spatial light modulator. Specifically, the scanning mirror is located on the front focal plane of the first lens in the 4f system, while the prism array is located on the coincident focal plane between the first and second lenses in the 4f system. The spatial light modulator is located on the rear focal plane of the second lens in the 4f system.

[0054] Thus, after the phased array lidar system outputs a scanning beam through the laser, the scanning mirror deflects the scanning beam output by the laser and then projects it onto the phase modulation plane of the spatial light modulator through the first lens, the prism array, and the second lens in sequence for scanning imaging.

[0055] It should be noted that the scanning mirror in the lidar system of the present invention can also be referred to as a galvanometer in some other feasible embodiments. This scanning mirror, controlled by the phased array lidar system, can oscillate within a certain range, thereby deflecting the scanning beam output by the laser at different angles. Furthermore, after being deflected by the scanning mirror, the scanning beam, after passing through the first and second lenses in the 4f system and projected onto the phase modulation plane of the spatial light modulator, can form a stable spot distribution on that phase modulation plane. This eliminates the need for the spatial light modulator's phase modulation pattern to be updated as the spot moves, reducing the update speed requirement for the spatial light modulator and freeing the phased array lidar from the imaging speed limitation of the spatial light modulator.

[0056] Furthermore, the spatial light modulators in the lidar system of this invention include, but are not limited to: spatial light modulators based on photoelectric crystals, liquid crystal spatial light modulators based on LCOS (Liquid Crystal on Silicon), and digital micromirror spatial light modulators. It should be understood that, based on different design requirements for practical applications, spatial light modulators not listed herein can be combined with scanning mirrors (or galvanometers) to form a phased array lidar system in any different feasible implementation. The lidar system of this invention does not limit the specific type of spatial light modulator.

[0057] Furthermore, in this embodiment, the prism array in the lidar system of the present invention can be a one-dimensional prism array or a two-dimensional prism array. When configuring a two-dimensional prism array in the lidar system, a two-dimensional scanning mirror is simultaneously configured for imaging. The lidar system of the present invention uses the prism array to deflect the scanning beam emitted from the scanning mirror at different angles, resulting in different deflections. This ensures that the light rays from different sub-fields within different fields of view are stably distributed on the phase modulation plane of the spatial light modulator, and each sub-field of view covers a different pixel of the spatial light modulator. Therefore, the lidar system of the present invention can achieve independent scanning of different sub-fields within the entire field of view.

[0058] In this embodiment, the lidar system provided by the present invention inserts a prism array on the overlapping focal plane between the first lens and the second lens in the 4f system to deflect light through the prism array, thereby generating multiple stable light spot regions on the spatial modulator. This achieves the segmentation of the entire field of view of the scanning mirror, thereby enabling ROI (region of interest) scanning of each independent sub-field of view in the entire field of view.

[0059] In addition, such as Figure 2 As shown, if only a 4f system is configured in the lidar system, but a prism array is not inserted on the coincident focal plane between the first and second lenses in the 4f system, then although the scanning beams emitted from the scanning mirror at different angles can be stably distributed on the phase modulation plane of the spatial light modulator, without the prism array to deflect the scanning beams, the entire field of view of the scanning mirror cannot be segmented. In this case, the lidar system can only use pixels at the same location on the spatial light modulator for scanning, and cannot independently scan different sub-fields of view.

[0060] In addition, such as Figure 3 As shown, if neither a 4f system nor a prism array is configured in the lidar system, the scanning beam emitted by the laser in the lidar system cannot form a stable distribution on the phase modulation plane of the spatial light modulator. That is, as the scanning mirror swings, the light spot formed by the scanning beam projected onto the phase modulation plane will also move accordingly. Thus, when the lidar system uses the pixels of the spatial light modulator for scanning, the phase pattern loaded on the spatial light modulator needs to move with the movement of the light spot. This causes the spatial light modulator to need to be refreshed continuously as the position of the light spot moves. Therefore, the refresh rate of the spatial light modulator will limit the scanning speed, and the spatial light modulator needs to have a large area. In addition, a large number of pixels of the spatial light modulator will be wasted during the entire scanning process.

[0061] Furthermore, in some feasible embodiments, the lidar system of the present invention further includes: a polarizer located between the laser and the scanning mirror;

[0062] The scanning beam output by the laser is converted into linearly polarized light by the polarizer, and the scanning mirror deflects the linearly polarized scanning beam at an angle.

[0063] like Figure 1As shown, as a feasible implementation, the lidar system provided in this embodiment of the invention also includes a polarizer for processing the scanning beam to make it linearly polarized between the laser that outputs the scanning beam and the scanning mirror that deflects the scanning beam at an angle.

[0064] It should be noted that in this embodiment, considering that some spatial light modulators have certain requirements for the polarization of the incident light, a polarizer is set between the laser and the scanning mirror of the lidar system to polarize the light into linearly polarized light. However, in some other feasible implementations, if the spatial light modulator set in the lidar system does not have polarization requirements for the incident light (for example, the spatial light modulator used is a digital micromirror), then it is of course possible not to set up the polarizer, so that the scanning mirror can directly deflect the non-linearly polarized light.

[0065] Furthermore, in some feasible embodiments, the lidar system of the present invention further includes: a collimating lens, the collimating lens being located between the laser and the polarizer;

[0066] The scanning beam output by the laser is collimated by the collimating lens and then becomes linearly polarized light by the polarizer.

[0067] like Figure 1 As shown, as a feasible implementation, the lidar system provided in this embodiment of the invention also provides a collimating lens for collimating the scanning beam between the laser that outputs the scanning beam and the polarizer.

[0068] In this embodiment, as Figure 4 As shown in the process, the scanning beam output by the laser of the phased array lidar system is collimated by a collimating lens and then becomes linearly polarized light by a polarizer. Then, the scanning mirror further deflects the linearly polarized scanning beam by angle, and then focuses it to the prism array by the first lens in the 4f system. The prism array deflects the scanning beam and then collimates it again into parallel light by the second lens in the 4f system before entering the spatial light modulator. Finally, the scanning beam, which is stably projected onto the phase modulation plane of the spatial light modulator, is modulated and then emitted into the target field of view.

[0069] At this point, the phased array lidar system can perform a rapid field-of-view traversal using the scanning mirror for a rough scan. Simultaneously or subsequently, due to the prism array deflecting the scanning beam, the entire field of view of the scanning mirror can be segmented into multiple sub-fields of view. Figure 1 The R1 to R7 symbols shown on the far right are for the sake of image simplicity and readability. Figure 1The left optical path section only plots three sub-fields of view (R1, R4, and R7) from R1 to R7, corresponding to the field of view ranges indicated by "R1 area pixels", "R4 area pixels", and "R7 area pixels". Thus, the phased array lidar system can further perform fine ROI scanning on these sub-fields of view using a spatial light modulator.

[0070] like Figure 5 As shown, Figure 5 This is a schematic diagram of the hardware operating environment of the terminal device involved in the embodiment of the present invention.

[0071] It should be noted that the terminal device in the embodiments of the present invention may be an environmental scanning device including the above-mentioned lidar system, and no specific limitation is made here.

[0072] like Figure 5 As shown, the terminal device may include: a processor 1001, such as a CPU; a network interface 1004; a user interface 1003; a memory 1005; and a communication bus 1002. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and an input unit such as a keyboard. Optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be high-speed RAM or non-volatile memory, such as a disk drive. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0073] Those skilled in the art will understand that Figure 5 The device structure shown does not constitute a limitation on the terminal device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0074] like Figure 5 As shown, the memory 1005, serving as a computer storage medium, may include an operating system, a network communication module, a user interface module, and the scanning program for the LiDAR system. The operating system is a program that manages and controls the hardware and software resources of the device, supporting the operation of the LiDAR system's scanning program and other software or programs. Figure 5 In the device shown, the user interface 1003 is mainly used for data communication with the client; the network interface 1004 is mainly used for establishing a communication connection with the server; and the processor 1001 can be used to call the scanning program of the lidar system stored in the memory 1005 and perform the following operations:

[0075] The scanning beam reflected by the scanning mirror is stably projected onto the phase modulation plane of the spatial light modulator through the 4f system to form the complete field of view of the scanning mirror;

[0076] The prism array is used to deflect the scanning beam passing through the 4f system to divide the complete field of view into individual segmented fields of view.

[0077] Scanning is performed on the complete field of view and / or each of the segmented fields of view.

[0078] Furthermore, the processor 1001 can also be used to call the scanning program of the lidar system stored in the memory 1005, and also perform the following operations:

[0079] The scanning mirror traverses the entire field of view to perform a coarse scan of the entire field of view;

[0080] And / or,

[0081] The spatial light modulator performs independent fine scanning of each of the segmented fields of view.

[0082] Furthermore, the lidar system also includes a polarizer, and the processor 1001 can also be used to call the lidar system's scanning program stored in the memory 1005, and before executing the scanning beam reflected by the scanning mirror through the 4f system, it also performs the following operations:

[0083] The polarizer processes the scanning beam into linearly polarized light.

[0084] The scanning beam is reflected by the scanning mirror to become linearly polarized light.

[0085] Furthermore, the lidar system also includes a collimating lens. The processor 1001 can also be used to call the lidar system's scanning program stored in the memory 1005, and before executing the process of converting the scanning beam into linearly polarized light through the polarizer, it also performs the following operations:

[0086] The scanning beam is collimated using the collimating lens;

[0087] Processor 1001 can also be used to call the scanning program of the lidar system stored in memory 1005, and also perform the following operations:

[0088] The collimated scanning beam is passed through the polarizer to process it into linearly polarized light.

[0089] Furthermore, the processor 1001 can also be used to call the scanning program of the lidar system stored in the memory 1005, and also perform the following operations:

[0090] The scanning mirror is controlled to swing to adjust the field of view of the complete field of view.

[0091] Based on the structure of the aforementioned terminal device, an embodiment of the scanning method of the lidar system of the present invention is proposed.

[0092] Please refer to Figure 6 , Figure 6 This is a flowchart illustrating the first embodiment of the scanning method of the lidar system of the present invention.

[0093] This invention provides an embodiment of a scanning method for a lidar system. It should be noted that although the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order. In this embodiment, the executing entity of the scanning method of the lidar system of this invention can be the aforementioned lidar system or a terminal device integrated with the aforementioned lidar system (hereinafter, the lidar system is used directly to represent each executing entity in the description of each embodiment).

[0094] In this embodiment, the scanning method of the lidar system of the present invention includes:

[0095] Step S10: The scanning beam reflected by the scanning mirror is stably projected onto the phase modulation plane of the spatial light modulator through the 4f system to form the complete field of view of the scanning mirror;

[0096] Step S20: The scanning beam passing through the 4f system is deflected by the prism array to divide the complete field of view into individual segmented fields of view;

[0097] Step S30: Scan the complete field of view and / or each of the segmented fields of view.

[0098] In this embodiment, after the lidar system outputs a scanning beam from the laser, the scanning mirror deflects the beam at an angle, and then projects it onto the phase modulation plane of the spatial light modulator via the first lens of the 4f system, the prism array, and the second lens of the 4f system for scanning and imaging. Furthermore, the lidar system uses the prism array to deflect the scanning beam at different angles, resulting in different deflections of the beam emitted from the scanning mirror. This ensures that the light from different sub-fields within the field of view is stably distributed on the phase modulation plane of the spatial light modulator, with each sub-field covering a different pixel of the spatial light modulator. Thus, the lidar system can synchronously or asynchronously perform phase modulation on the spatial light modulator to form a complete field of view and scan the sub-fields obtained by deflecting the light from the prism array to divide the complete field of view.

[0099] Furthermore, in some feasible embodiments, step S30 described above may specifically include:

[0100] Step S301: Traverse the entire field of view through the scanning mirror to perform a coarse scan of the entire field of view;

[0101] Step S302: Perform independent fine scanning of each of the segmented fields of view using the spatial light modulator.

[0102] In this embodiment, the lidar system performs a rapid field-of-view traversal using a scanning mirror for a coarse scan. Furthermore, because the prism array deflects the scanning beam, it can segment the entire field of view of the scanning mirror into multiple sub-fields of view. Therefore, the lidar system can perform a fine ROI scan on each sub-field of view simultaneously with or after the rapid traversal scan of the complete field of view using a spatial light modulator.

[0103] Furthermore, in some feasible embodiments, the scanning method of the lidar system of the present invention may further include:

[0104] Step S40: Control the scanning mirror to swing to adjust the field of view of the complete field of view.

[0105] In this embodiment, when the lidar system performs a full-field scan of the scanning mirror, it can also control the scanning mirror to swing within a certain range to deflect the scanning beam output by the laser at different angles, thereby adjusting the field of view of the full-field of view of the scanning mirror to perform a field of view scan with a larger angle range.

[0106] Furthermore, in some feasible embodiments, the lidar system further includes a polarizer. Prior to the step described above of reflecting the scanning beam from the scanning mirror via the 4f system, the scanning method of the lidar system of the present invention may further include:

[0107] The polarizer processes the scanning beam into linearly polarized light.

[0108] The scanning beam is reflected by the scanning mirror to become linearly polarized light.

[0109] In this embodiment, the lidar system also includes a polarizer positioned between the laser that outputs the scanning beam and the scanning mirror that deflects the scanning beam at an angle. This polarizer is used to process the scanning beam to make it linearly polarized. Thus, the lidar system can use this polarizer to polarize the scanning beam output from the laser to make it linearly polarized. Then, the scanning mirror further deflects the linearly polarized scanning beam at an angle before reflecting it onto the phase modulation plane of the spatial light modulator.

[0110] Furthermore, in some feasible embodiments, the lidar system further includes a collimating lens. Prior to the step of processing the scanning beam into linearly polarized light via the polarizer described above, the scanning method of the lidar system of the present invention may further include:

[0111] The scanning beam is collimated using the collimating lens;

[0112] In this embodiment, the lidar system provided by this invention also includes a collimating lens between the laser that outputs the scanning beam and the polarizer for collimating the scanning beam. Thus, the scanning beam output by the laser of the lidar system is first collimated into parallel light by the collimating lens.

[0113] Based on this, the above-mentioned step of processing the scanning beam into linearly polarized light using the polarizer may specifically include:

[0114] The collimated scanning beam is passed through the polarizer to process it into linearly polarized light.

[0115] In this embodiment, the scanning beam output from the laser of the lidar system, after being collimated by a collimating lens to become parallel light, is further polarized by a polarizer to become linearly polarized light. Thus, the scanning mirror further deflects the linearly polarized scanning beam at an angle and reflects it onto the phase modulation plane of the spatial light modulator.

[0116] In this embodiment, the scanning beam output from the laser of the lidar system is collimated by a collimating lens and then polarized by a polarizer. The scanning mirror further deflects the linearly polarized scanning beam, which is then focused by the first lens in the 4f system onto a prism array. The prism array deflects the beam, and the beam is then collimated again by the second lens in the 4f system to become parallel light before entering the spatial light modulator. Finally, the scanning beam, stably projected onto the phase modulation plane of the spatial light modulator, is modulated and exits into the target field of view. At this point, the lidar system can perform a rapid field-of-view traversal using the scanning mirror for a coarse scan. Because the prism array deflects the scanning beam, it can divide the entire field of view of the scanning mirror into multiple sub-fields of view. Therefore, simultaneously or subsequently, the phased array lidar system can further perform a fine scan of each sub-field of view using the spatial light modulator.

[0117] Thus, this invention expands the field of view of the phased array lidar based on the spatial light modulator by oscillating the scanning mirror in the phased array lidar to adjust the deflection angle of the scanning beam. Furthermore, this invention achieves the segmentation of the scanning field of view by deflecting light rays at different angles within the entire field of view of the prism array scanning mirror, deflecting the sub-field beams of different angle ranges to different positions on the spatial light modulator. This effectively avoids pixel waste of the spatial light modulator, thereby enabling rapid coarse scanning of the entire field of view of the scanning mirror and near-simultaneous fine scanning of multiple targets in the field of view, effectively improving the scanning efficiency of the phased array lidar.

[0118] Furthermore, by employing a 4f system, this invention ensures the stability of the scanning beam on the spatial light modulator, so that the phase modulation pattern of the spatial light modulator does not need to be updated as the scanning spot moves, reducing the requirements for the update speed of the spatial light modulator. The overall field-of-view traversal speed of the system through the scanning mirror is not limited by the refresh speed of the spatial light modulator.

[0119] Furthermore, this embodiment of the invention also proposes a scanning device for a lidar system.

[0120] Please refer to Figure 7 The scanning device of the laser radar system of the present invention is applied to the laser radar system described above. The scanning device of the laser radar system of the present invention includes:

[0121] The light control module 10 is used to stably project the scanning beam reflected by the scanning mirror onto the phase modulation plane of the spatial light modulator through the 4f system to form the complete field of view of the scanning mirror;

[0122] The field of view segmentation module 20 is used to deflect the scanning beam passing through the 4f system using the prism array to segment the complete field of view into individual segmented fields of view;

[0123] The field-of-view scanning module 30 is used to scan the complete field of view and / or each of the segmented fields of view.

[0124] In one feasible implementation, the field-of-view scanning module 30 includes:

[0125] A coarse scanning unit is used to traverse the complete field of view through the scanning mirror to perform a coarse scan of the complete field of view;

[0126] A fine scanning unit is used to perform independent fine scanning of each of the segmented fields of view using the spatial light modulator.

[0127] In one feasible implementation, the lidar system further includes: a polarizer; the scanning device light control module 10 of the lidar system of the present invention is further used for:

[0128] The scanning beam is processed into linearly polarized light by the polarizer; and the scanning beam is reflected into linearly polarized light by the scanning mirror.

[0129] In one feasible embodiment, the lidar system further includes: a collimating lens; the scanning device light control module 10 of the lidar system of the present invention is further used for:

[0130] The scanning beam is collimated by the collimating lens; and the collimated scanning beam is processed into linearly polarized light by the polarizer.

[0131] In one feasible embodiment, the light control module 10 of the scanning device of the lidar system of the present invention is further used for:

[0132] The scanning mirror is controlled to swing to adjust the field of view of the complete field of view.

[0133] The extended content of the specific implementation of the scanning device of the lidar system of the present invention is basically the same as the various embodiments of the scanning method of the lidar system described above, and will not be repeated here.

[0134] Furthermore, this embodiment of the invention also proposes a computer storage medium storing a scanning program for a lidar system. When the scanning program for the lidar system is executed by a processor, it implements the steps of the scanning method for the lidar system as described below.

[0135] The extended content of the specific implementation of the computer storage medium of the present invention is basically the same as the various embodiments of the scanning method of the above-mentioned lidar system, and will not be repeated here.

[0136] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0137] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0138] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0139] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A lidar system, characterized in that, The lidar system includes: a laser, a scanning mirror, a 4f system, a prism array, and a spatial light modulator; The scanning mirror is located on the front focal plane of the first lens in the 4f system, the spatial light modulator is located on the rear focal plane of the second lens in the 4f system, and the prism array is located on the overlapping focal plane between the first lens and the second lens; The scanning mirror deflects the scanning beam output by the laser at an angle and then projects it onto the phase modulation plane of the spatial light modulator through the first lens, the prism array, and the second lens in sequence for scanning and imaging. The 4f system is used to stably project the scanning beam reflected by the scanning mirror onto the phase modulation plane of the spatial light modulator to form the complete field of view of the scanning mirror. The prism array is used to deflect the scanning beam passing through the 4f system to divide the complete field of view into individual segmented fields of view; The scanning mirror is used to scan the entire field of view, and the spatial light modulator is used to scan each of the segmented fields of view.

2. The lidar system as described in claim 1, characterized in that, The lidar system further includes a polarizer located between the laser and the scanning mirror; The scanning beam output by the laser is converted into linearly polarized light by the polarizer, and the scanning mirror deflects the linearly polarized scanning beam at an angle.

3. The lidar system as described in claim 2, characterized in that, The lidar system further includes a collimating lens, which is located between the laser and the polarizer; The scanning beam output by the laser is collimated by the collimating lens and then becomes linearly polarized light by the polarizer.

4. A scanning method for a lidar system, characterized in that, The scanning method of the lidar system is applied to the lidar system as described in any one of claims 1 to 3, wherein the lidar system includes a scanning mirror, a prism array, a 4f system, and a spatial light modulator, and the scanning method of the lidar system includes: The scanning beam reflected by the scanning mirror is stably projected onto the phase modulation plane of the spatial light modulator through the 4f system to form the complete field of view of the scanning mirror; The prism array is used to deflect the scanning beam passing through the 4f system to divide the complete field of view into individual segmented fields of view. Scanning is performed on the complete field of view and / or each of the segmented fields of view.

5. The scanning method of the lidar system as described in claim 4, characterized in that, The step of scanning the complete field of view and / or each of the segmented fields of view includes: The scanning mirror traverses the entire field of view to perform a coarse scan of the entire field of view; And / or, The spatial light modulator performs independent fine scanning of each of the segmented fields of view.

6. The scanning method of the lidar system as described in claim 4, characterized in that, The lidar system further includes a polarizer before the scanning beam reflected by the scanning mirror through the 4f system; the method further includes: The polarizer processes the scanning beam into linearly polarized light. The scanning beam is reflected by the scanning mirror to become linearly polarized light.

7. The scanning method of the lidar system as described in claim 6, characterized in that, The lidar system further includes a collimating lens, and the method further includes, before the scanning beam is processed into linearly polarized light by the polarizer: The scanning beam is collimated using the collimating lens; The process of converting the scanning beam into linearly polarized light using the polarizer includes: The collimated scanning beam is passed through the polarizer to process it into linearly polarized light.

8. The scanning method of the lidar system as described in claim 4, characterized in that, The method further includes: The scanning mirror is controlled to swing to adjust the field of view of the complete field of view.

9. A terminal device, characterized in that, The terminal includes: a lidar system as described in any one of claims 1 to 3, a memory, a processor, and a scanning program for the lidar system stored in the memory and executable on the processor. When the scanning program for the lidar system is executed by the processor, it implements the steps of the scanning method for the lidar system as described in any one of claims 4 to 8.

10. A computer storage medium, characterized in that, The computer-readable storage medium stores a scanning program for a lidar system, which, when executed by a processor, implements the steps of the lidar system scanning method as described in any one of claims 4 to 8.

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