Photon detection method, device and laser radar for all-solid-state laser radar

Abstract

The application provides a photon detection method, device and laser radar for a full solid-state laser radar, the method comprising: calibrating a SPAD array, determining SPAD units included in a photosensitive pixel corresponding to each light spot or light strip emitted in a laser, and recording the SPAD units as an initial opening region; opening the SPAD units of the initial opening region to detect a target; obtaining histogram data output by the opened SPAD units; adaptively adjusting the position of the SPAD units opened next time according to the histogram data, when the signal-to-noise ratio in the histogram data of the SPAD units opened next time meets a set value, the SPAD units opened next time are required SPAD units; and calculating distance information of the target according to the histogram data output by the required SPAD units. Through region calibration of the SPAD array, the opening position of the SPAD units is adaptively adjusted based on the signal-to-noise ratio for photon reception at each exposure, which ensures the detection effect while effectively reducing the detection power consumption and data volume.

Description

Technical Field

[0001] This invention relates to the field of depth sensing technology, and more particularly to a photon detection method, device, and lidar for all-solid-state lidar. Background Technology

[0002] Currently, LiDAR is one of the indispensable depth sensors in autonomous driving technology, used to obtain distance information between the car and the target object, and combined with other sensors to provide decision-making for autonomous driving.

[0003] LiDAR calculates distance by measuring the time-of-flight (ToF) of light emitted from the transmitter (TX) and reflected back to the receiver (RX) from the target object. The most important component is the photon detector, an optoelectronic device sensitive to photons, which converts photon-level optical signals into electrical signals, thereby enabling timing.

[0004] Flash-type lidar, which combines a large array of photon detectors, operates similarly to a camera. A single exposure can record the distance information of the entire scene. However, the large number of pixels increases power consumption and also makes signal transmission and processing difficult. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a photon detection method, device and lidar for all-solid-state lidar, so as to reduce the detection power consumption and data volume of lidar.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides a photon detection method for all-solid-state lidar, comprising the following steps:

[0008] The SPAD array is calibrated to determine the SPAD units included in the photosensitive pixels corresponding to each light spot or stripe emitted in the laser, and these units are recorded as the initial open area.

[0009] The SPAD unit in the initially activated area is activated to detect the target;

[0010] Obtain the histogram data output by the enabled SPAD cells;

[0011] Based on the histogram data, the position of the SPAD unit to be activated in the next exposure is adaptively adjusted. When the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets the set value, the next activated SPAD unit is the required SPAD unit.

[0012] The distance information of the target is calculated based on the histogram data output by the required SPAD unit.

[0013] In one embodiment, adaptively adjusting the position of the SPAD unit activated for the next exposure based on the histogram data includes:

[0014] Confirm whether there are signal peaks in the n*n histogram data output by the n*n activated SPAD units;

[0015] If there is no signal peak in the n histogram data, then the n SPAD units are turned off during the next exposure, and n SPAD units are turned on in the opposite direction based on the coordinates of the no signal peak.

[0016] In one embodiment, when 3*3 SPAD units constitute a superpixel, if the 3 SPAD units on the right have no signal peaks, then 3 more SPAD units are added and enabled on the left.

[0017] In one embodiment, the method prior to confirming whether a signal peak exists in the n*n histogram data output by the n*n activated SPAD units further includes:

[0018] The histogram data is then subjected to noise reduction processing.

[0019] In one embodiment, the noise reduction processing of the histogram data includes:

[0020] Randomly sample the histogram data to obtain ambient light data;

[0021] The histogram data is denoised based on the ambient light data to obtain primary denoised histogram data.

[0022] The count values ​​below a preset threshold in the primary denoising histogram data are set to zero, and the signal is amplified by a matched filter to obtain the secondary denoising histogram data.

[0023] In one embodiment, when detecting target objects at different distances, the position of the SPAD unit activated in the next exposure should be adaptively adjusted.

[0024] In one embodiment, the SPAD array is divided into m partitions, and an exposure is performed sequentially on the m partitions; the next exposure is performed sequentially on each of the m partitions.

[0025] A second aspect of the present invention provides a photon detection device for an all-solid-state lidar, comprising:

[0026] The calibration module is used to calibrate the SPAD array, determine the SPAD units included in the photosensitive pixels corresponding to each light spot or stripe emitted in the laser, and record them as the initial open area.

[0027] The control module is used to activate the SPAD unit in the initially activated area to detect the target;

[0028] The data processing module is used to acquire histogram data output by the activated SPAD units;

[0029] The control module is also used to adaptively adjust the position of the SPAD unit to be activated in the next exposure based on the histogram data. When the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets the set value, the next activated SPAD unit is the required SPAD unit.

[0030] The data processing module is also used to calculate the target distance information based on the histogram data output by the required SPAD unit.

[0031] In one embodiment, the apparatus further includes:

[0032] The noise reduction module is used to perform noise reduction processing on the histogram data.

[0033] A third aspect of the present invention provides a lidar comprising a photon detection device for an all-solid-state lidar as described above.

[0034] The beneficial effects of this invention are as follows: It provides a photon detection method, device and lidar for all-solid-state lidar. By performing regional calibration on the SPAD array, the on-state of the SPAD unit is adaptively adjusted based on the signal-to-noise ratio during each exposure to receive photons, thereby ensuring the detection effect while effectively reducing detection power consumption and data volume. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0036] Figure 1 This is a flowchart of a photon detection method for all-solid-state lidar in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of a region calibration method according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of a disparity model in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of optical center offset on a SPAD array according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of an adaptive SPAD unit activation embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of a two-stage noise reduction process in an embodiment of the present invention;

[0042] Figure 7 This is a structural diagram of a photon detection device for an all-solid-state lidar in an embodiment of the present invention. Detailed Implementation

[0043] To make the technical problems, technical solutions, and beneficial effects of the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0044] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be for both fixing and circuit connection purposes.

[0045] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present 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. Therefore, they should not be construed as limitations on the present invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] The all-solid-state lidar dynamic exposure method provided in this invention is applied to an all-solid-state lidar detection system based on the time-of-flight (TOF) method. This all-solid-state lidar detection system includes at least a controller, a transmitter, and a receiver. The controller is connected to both the transmitter and the receiver. The transmitter emits a detection beam towards a target object, and at least a portion of the detection beam is reflected by the target object to form reflected light. The receiver includes a pixel array composed of multiple pixels, used to receive the reflected light reflected back from the target object. The controller synchronously controls the emission and reception of light, performs histogram statistics on the photons received by the receiver by distinguishing them by time bins, and then calculates the time of flight of the photons using the histogram to determine the distance to the target object.

[0048] Specifically, the transmitter includes a driver and a light source, which can be a light-emitting diode (LED), a laser diode (LD), an edge-emitting laser (EEL), a vertical-cavity surface-emitting laser (VCSEL), a picosecond laser, etc. Under the drive and control of the driver, the light source emits a detection beam, which can be visible light, infrared light, ultraviolet light, etc. At least a portion of the detection beam is emitted toward the target object, and the reflected light generated by the reflection of at least a portion of the detection beam by the target object is received by the receiver.

[0049] The receiver includes a pixel array and receiving optical elements, which can be one or more combinations of lenses, microlens arrays, mirrors, etc. The receiving optical elements receive reflected light and guide it to the pixel array. The pixel array includes multiple pixels that collect photons. In one embodiment, the pixel array consists of multiple single-photon avalanche photodiodes (SPADs). The SPADs can respond to the incident single photon and output a photon signal indicating the arrival time of the received photon at each SPAD. Of course, in other embodiments, photoelectric conversion devices such as avalanche photodiodes, photomultiplier tubes, silicon photomultiplier tubes, etc., can also be used.

[0050] Currently, all-solid-state lidar detection systems offer advantages such as simple assembly and high reliability. Flash-type lidar, combined with a large-array photon detector, operates similarly to a camera, recording distance information for the entire scene in a single exposure. However, the large number of pixels increases power consumption and leads to difficulties in signal transmission and processing. Therefore, the following describes how to solve this problem using a photonic method applied to all-solid-state lidar detection systems. This approach aims to reduce lidar detection power consumption and data volume from the photon receiving perspective, ensuring detection effectiveness while improving detection efficiency.

[0051] like Figure 1 As shown, Figure 1This is a flowchart of a photon detection method for an all-solid-state lidar according to one embodiment of the present invention. The method specifically includes the following steps:

[0052] S101. The SPAD array is calibrated to determine the SPAD units included in the photosensitive pixels corresponding to each light spot or light stripe emitted in the laser, and these units are recorded as the initial open area.

[0053] S102. Activate the SPAD unit in the initially activated area to detect the target.

[0054] In this embodiment, the all-solid-state lidar optical system consists of a vertical-cavity surface-emitting laser (VCSEL) at the transmitter (TX) and a photon detector array at the receiver (RX). Figure 2 As shown in (a) above, the photon detector array (SPAD array in this embodiment) consists of multiple detector pixels (i.e., SPAD units), as follows: Figure 2 As shown in (b), the VCSEL has multiple light-emitting dots (Dots), and the light emission of each dot is independent and controllable.

[0055] If a specified emitting spot is turned on during exposure, only the corresponding SPAD unit can receive light. Therefore, to reduce energy consumption, the SPAD array can be calibrated before leaving the factory to determine the SPAD units included in the photosensitive pixel corresponding to each emitting spot or stripe in the laser. These are recorded only as the initial open area. During detection, the SPAD units in the recorded initial open area are turned on to detect the target, achieving low-power and low-data-volume partitioned exposure detection.

[0056] Specifically, zoned exposure can be performed by row or column, allowing the illumination points of a specific row or column to be activated during exposure, and activating the SPAD units (e.g., ...) included in the photosensitive pixels corresponding to the light stripe formed by the current illumination point. Figure 3 (Nth row of pixels); or it can be done according to the row and column coordinates of a smaller area. During exposure, the luminous scattering points at specified row and column coordinates can be activated, and the SPAD units (such as those in the photosensitive pixels corresponding to the light spots formed by the current luminous scattering points) can be activated. Figure 3 (Pixels in the 2nd row and 3rd column). It's understandable that the photosensitive pixel corresponding to a single light spot can be a superpixel comprising multiple SPAD units, for example, each light spot covering 2*2 or 3*3 SPAD units, etc. By precisely opening a smaller exposure area, the data volume and power consumption of the all-solid-state LiDAR are effectively reduced.

[0057] S103. Obtain the histogram data output by the enabled SPAD unit;

[0058] S104. Based on the histogram data, adaptively adjust the position of the SPAD unit to be activated in the next exposure. When the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets the set value, the next activated SPAD unit is the required SPAD unit.

[0059] S105. Calculate the target distance information based on the histogram data output by the required SPAD unit.

[0060] While using SPAD units for exposure acquisition in partitioned exposures can reduce data volume and power consumption, it can also lead to decreased detection accuracy if the initially activated SPAD units cannot accurately receive the light signal during partitioned exposure. To ensure accurate and complete reception of the light emitted from the transmitter during partitioned exposure, this embodiment flexibly adjusts the position of the activated SPAD units using an adaptive adjustment method.

[0061] Specifically, at the end of a partitioned exposure, the histogram data output by the activated SPAD units is acquired. Based on this histogram data, it is determined whether the current signal-to-noise ratio (SNR) meets the requirements. If the SNR of the currently activated SPAD unit's histogram data meets the set value, it indicates that the accuracy of this exposure is high, and the target distance information can be directly calculated. If the current SNR does not meet the set value, the position of the SPAD unit activated in the next exposure is adaptively adjusted based on the histogram data. This allows the position of the corresponding photon-receiving SPAD unit to be adaptively adjusted based on the position of the light spot or light streak. After the next exposure, the histogram data SNR is again checked to see if it meets the set value. If it does not, the adjustment continues; if it does, the next activated SPAD unit is one that can accurately receive photons. By acquiring the histogram data output by the adjusted SPAD units, a histogram is constructed, and peak finding is used to calculate the accurate target distance information. This embodiment, based on partitioned exposure, achieves low-data-volume, low-power detection by adaptively adjusting the position of the activated SPAD units, while also avoiding the problem of inaccurate detection.

[0062] In one embodiment, when detecting target objects at different distances, the position of the SPAD unit activated in the next exposure should be adaptively adjusted.

[0063] In this embodiment, the emitting points at different locations and the corresponding SPAD units have different detection ranges. During adaptive adjustment, the distance range that each initial open area can accurately detect can be pre-calibrated. When detecting target objects at different distances, the distance range of the target object is roughly determined based on the histogram data obtained from the previous exposure. Thus, based on the distance range and the calibration relationship between each initial open area, the position of the SPAD unit activated in the next exposure is adaptively adjusted to achieve accurate detection of the distance range of the target object quickly.

[0064] In one embodiment, the SPAD array is divided into m partitions, and an exposure is performed sequentially on the m partitions; the next exposure is performed sequentially on each of the m partitions.

[0065] In this embodiment, based on the calibration and recording of multiple initial activation regions corresponding to the transmitter, the SPAD array is further divided into m partitions for partitioned exposure. Each partition may include one or more initial activation regions, and the number of SPAD units in each partition may be the same or different; this embodiment does not limit this. During partitioned exposure, each round of exposure controls the m partitions to be exposed one by one according to a certain exposure order. During each exposure, only the initially determined or adaptively adjusted SPAD units within the current exposure partition are activated for sampling. After one round of exposure, histogram data of all activated SPAD units is acquired. By using partitioned cyclic exposure acquisition, the waste of optical power can be reduced, further lowering the system power consumption of the lidar.

[0066] In one embodiment, adaptively adjusting the position of the SPAD unit activated for the next exposure based on the histogram data includes:

[0067] Confirm whether there are signal peaks in the n*n histogram data output by the n*n activated SPAD units;

[0068] If there is no signal peak in the histogram data of n SPADs (n SPADs in the same column), then the n SPAD units are turned off during the next exposure, and n SPAD units in the same column are added and turned on in the opposite direction based on the coordinates of the no signal peak.

[0069] In this embodiment, when the n*n SPAD units included in the photosensitive pixel corresponding to the light spot are activated with a smaller exposure area, such as Figure 3As shown, parallax causes optical center shift, meaning that as the target object moves closer or further away, the optical center of the light emitted from the transmitter shifts in one direction on the imaging surface of the receiver. This results in some activated SPAD units not receiving the light emitted from the transmitter. Therefore, if the target object's position changes during detection, causing the SPAD units activated in the current exposure to only receive diffused light, the position of the SPAD units activated in the next exposure is adaptively adjusted based on the optical center shift.

[0070] Specifically, the system receives n*n histogram data output from the n*n SPAD units already activated in the current exposure, pixel by pixel. It determines whether signal peaks exist in the histogram data and marks the SPAD units without signal peaks. If no signal peaks are found in the n histogram data output from the n SPAD units on one side, it indicates that the optical center has shifted away from these n signal-peak-free SPAD units. Therefore, based on the coordinates of the marked signal-peak-free SPAD units, the n signal-peak-free SPAD units on this side are turned off in the next exposure, and the other side's n SPAD units are newly activated in the opposite direction. This ensures that the position of the activated SPAD units in the next exposure can adapt to the shift in the optical center, avoiding the problem of activated SPAD units receiving diffused light due to optical center shift, thus reducing detection accuracy and causing energy waste.

[0071] In one embodiment, when 3*3 SPAD units constitute a superpixel, if the 3 SPAD units on the right have no signal peaks, then 3 more SPAD units are added and enabled on the left.

[0072] like Figure 4 and Figure 5 As shown, if the superpixels in the 2nd row and 3rd column are enabled in this exposure, which include n*n SPAD units, for example, 3*3 SPAD units, the optical center on the SPAD array moves from the cross position to the left to the circular position as the target moves due to parallax. Since the energy of the light spot is strongest at the optical center, the energy of the light spot gradually decreases as the position shifts. This results in the rightmost 3 SPAD units of the already enabled superpixel ( Figure 5 The histogram data output from region A (center) shows no signal peak. To avoid wasting light and energy, the three SPAD units on the right are turned off during the next exposure, and three new SPAD units are turned on on the left in the opposite direction. Figure 5(Region B) Thus, the position of the SPAD unit activated during the next exposure can cover the position of the optical center, thereby receiving the light signal completely and accurately to achieve precise ranging. Similarly, when the optical center shifts to other directions, such as to the right, up, or down, the received histogram data can be used to simultaneously activate a new SPAD unit while turning off the SPAD unit with no signal peak. The adaptive adjustment process is the same as in the above embodiment and will not be described in detail here.

[0073] In one embodiment, before confirming whether there is a signal peak in the n*n histogram data output by the n*n activated SPAD units, the method further includes:

[0074] The histogram data is then subjected to noise reduction processing.

[0075] In this embodiment, the adaptive adjustment of the SPAD unit's activation position requires accurate identification of the presence of signal peaks in the histogram data. However, in outdoor environments, the histogram data of the timestamp and photon count relationship collected by the lidar contains both valid signals and background noise. Background noise may interfere with the identification of signal peaks, thus affecting the accuracy of adaptive adjustment. Therefore, noise reduction processing is performed before identifying the presence of signal peaks in the histogram data to ensure accurate peak identification processing of the noise-free data and improve the accuracy of signal peak identification.

[0076] In one embodiment, the noise reduction processing of the histogram data includes:

[0077] Randomly sample the histogram data to obtain ambient light data;

[0078] The histogram data is denoised based on the ambient light data to obtain primary denoised histogram data.

[0079] The count values ​​below a preset threshold in the primary denoising histogram data are set to zero, and the signal is amplified by a matched filter to obtain the secondary denoising histogram data.

[0080] In this embodiment, the histogram data undergoes two-stage noise reduction processing, such as... Figure 6 As shown in (a), the original histogram data is first randomly sampled to obtain ambient light data; as... Figure 6 As shown in (b), during the first stage of noise reduction, the ambient light data is subtracted from the histogram data, which can effectively filter out most of the ambient light and obtain the primary noise-reduced histogram data; as Figure 6As shown in (c), during the second stage of noise reduction, a preset threshold is set, and all count values ​​below the preset threshold in the data after the first stage of noise reduction are set to zero. The effective signal is amplified by a matched filter, and a high signal-to-noise ratio result can be obtained. This allows for accurate determination of whether there is a signal peak, providing a reliable basis for adaptively adjusting the switching state of the SPAD unit.

[0081] It should be noted that there is no necessary order between the above steps. Those skilled in the art will understand from the description of the embodiments of the present invention that the above steps may have different execution orders in different embodiments, that is, they may be executed in parallel or in turn, etc.

[0082] The present invention also provides a photon detection device for all-solid-state lidar, such as... Figure 7 As shown, Figure 7 This is a structural diagram of a photon detection device for an all-solid-state lidar according to an embodiment of the present invention. It includes a calibration module 701, a control module 702, and a data processing module 703, which are connected sequentially. The calibration module 701 calibrates the SPAD array, determining the SPAD units included in the photosensitive pixels corresponding to each emitted light spot or stripe in the laser, and recording this as an initial activation area. The control module 702 activates the SPAD units in the initial activation area to detect the target. The data processing module 703 acquires the histogram data output by the activated SPAD units. The control module 702 also adaptively adjusts the position of the activated SPAD units for the next exposure based on the histogram data. When the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets a set value, the next activated SPAD unit is the desired SPAD unit. The data processing module 703 calculates the target distance information based on the histogram data output by the desired SPAD unit. Since the above method embodiments have already described the photon detection process for all-solid-state lidar in detail, please refer to the corresponding method embodiments above for details, and will not be repeated here.

[0083] In one embodiment, the photon detection device for all-solid-state lidar further includes a noise reduction module, which is used to perform noise reduction processing on the histogram data. Since the above method embodiments have already described the noise reduction processing in the photon detection process for all-solid-state lidar in detail, please refer to the corresponding method embodiments above for further information; elaboration will not be repeated here.

[0084] The present invention also provides a lidar, which includes the photon detection device for all-solid-state lidar as described above. Since the photon detection process for all-solid-state lidar has been described in detail in the above method embodiments, please refer to the corresponding method embodiments above for details, and will not be repeated here.

[0085] In summary, this invention provides a photon detection method, apparatus, and lidar for all-solid-state lidar. The method includes: calibrating a SPAD array to determine the SPAD units included in the photosensitive pixels corresponding to each emitted spot or stripe in the laser, and recording them as initial activation areas; activating the SPAD units in the initial activation areas to detect the target; acquiring histogram data output by the activated SPAD units; adaptively adjusting the position of the activated SPAD units for the next exposure based on the histogram data; when the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets a set value, the next activated SPAD unit is the desired SPAD unit; and calculating the target distance information based on the histogram data output by the desired SPAD unit. By calibrating the SPAD array and adaptively adjusting the activation position of the SPAD units based on the signal-to-noise ratio for photon reception during each exposure, the detection effect is ensured while effectively reducing detection power consumption and data volume.

[0086] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several equivalent substitutions or obvious modifications can be made without departing from the concept of the present invention, and all such modifications, achieving the same performance or purpose, should be considered within the scope of protection of the present invention.

Claims

1. A photon detection method for all-solid-state lidar, characterized in that, Includes the following steps: The SPAD array is calibrated to determine the SPAD units included in the photosensitive pixels corresponding to each light spot or stripe emitted in the laser, and these units are recorded as the initial open area. The specified luminous points are activated by row or column or specified row and column coordinates, and only the SPAD units included in the initial activation area corresponding to the light stripe or spot formed by the current luminous points are activated to detect the target; Obtain the histogram data output by the enabled SPAD cells; Based on the histogram data, the position of the SPAD unit to be activated in the next exposure is adaptively adjusted based on the offset of the optical center. When the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets the set value, the next activated SPAD unit is the required SPAD unit. The distance information of the target is calculated based on the histogram data output by the required SPAD unit. The step of adaptively adjusting the position of the SPAD unit activated during the next exposure based on the histogram data includes: Confirm that n is already enabled n outputs from n SPAD units Whether there is a signal peak in the n histogram data, and mark the SPAD units without signal peaks; If there is no signal peak in the n histogram data output by n SPAD units in the same column on one side, then the n SPAD units on this side are turned off during the next exposure, and the n SPAD units in the same column on the other side are turned on in the opposite direction based on the coordinates of the no signal peak.

2. The photon detection method for all-solid-state lidar according to claim 1, characterized in that, When 3 When three SPAD units constitute a superpixel, if the three SPAD units on the right have no signal peaks, then three more SPAD units are added and enabled on the left.

3. The photon detection method for all-solid-state lidar according to claim 1, characterized in that, The confirmation that n has been enabled n outputs from n SPAD units The method prior to determining whether a signal peak exists in the n histogram data points also includes: The histogram data is then subjected to noise reduction processing.

4. The photon detection method for all-solid-state lidar according to claim 3, characterized in that, The noise reduction process for the histogram data includes: Randomly sample the histogram data to obtain ambient light data; The histogram data is denoised based on the ambient light data to obtain primary denoised histogram data. The count values ​​below a preset threshold in the primary denoising histogram data are set to zero, and the signal is amplified by a matched filter to obtain the secondary denoising histogram data.

5. The photon detection method for all-solid-state lidar according to claim 1, characterized in that, When detecting target objects at different distances, the position of the SPAD unit activated in the next exposure should be adaptively adjusted.

6. The photon detection method for all-solid-state lidar according to claim 1, characterized in that, The SPAD array is divided into m partitions. One exposure is performed sequentially on all m partitions; the next exposure is performed sequentially on each of the m partitions.

7. A photon detection device for all-solid-state lidar, characterized in that, include: The calibration module is used to calibrate the SPAD array, determine the SPAD units included in the photosensitive pixels corresponding to each light spot or stripe emitted in the laser, and record them as the initial open area. The control module is used to activate specified luminous points by row or column or specified row and column coordinates, and only activate the SPAD units included in the initial activation area corresponding to the light stripe or spot formed by the current luminous point, so as to detect the target; The data processing module is used to acquire histogram data output by the activated SPAD units; The control module is also used to adaptively adjust the position of the SPAD unit to be activated in the next exposure based on the offset of the optical center according to the histogram data. When the signal-to-noise ratio in the histogram data of the next activated SPAD unit meets the set value, the next activated SPAD unit is the required SPAD unit. The data processing module is also used to calculate the target distance information based on the histogram data output by the required SPAD unit. The step of adaptively adjusting the position of the SPAD unit activated during the next exposure based on the histogram data includes: Confirm that n is already enabled n outputs from n SPAD units Whether there is a signal peak in the n histogram data, and mark the SPAD units without signal peaks; If there is no signal peak in the n histogram data output by n SPAD units in the same column on one side, then the n SPAD units on this side are turned off during the next exposure, and the n SPAD units in the same column on the other side are turned on in the opposite direction based on the coordinates of the no signal peak.

8. The photon detection device for all-solid-state lidar according to claim 7, characterized in that, The device further includes: The noise reduction module is used to perform noise reduction processing on the histogram data.

9. A lidar, characterized in that, Including the photon detection device for all-solid-state lidar as described in claim 6.

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