A ranging method, laser radar and computer storage medium
By setting different energy level regions in the SPAD array and utilizing the energy distribution differences of the echo spot, the ranging calculation area can be flexibly adjusted, solving the problem of insufficient ranging accuracy of lidar in strong backlight scenarios and achieving higher ranging accuracy and anti-saturation performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AOCHENG INFORMATION TECH (SHANGHAI) CO LTD
- Filing Date
- 2026-04-23
- Publication Date
- 2026-06-19
AI Technical Summary
In close-range, high-reflectivity, and strong backlighting scenarios, the ranging accuracy of lidar is affected, and existing technologies struggle to effectively reduce the impact of single-bin and pile-up effects.
By using energy gradient settings in different energy level regions of the SPAD array, the echo spot is distributed to different energy level regions of the SPAD array through a point spread function, which flexibly adjusts the SPAD pixel area used for ranging calculation and reduces the impact of excessively strong or weak photon signals on ranging accuracy.
It improves the ranging accuracy of lidar in strong backlighting scenarios, enhances its anti-saturation performance and anti-pile-up effect capabilities, and improves its versatility in different light intensity scenarios.
Smart Images
Figure CN122239073A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of lidar, and more specifically, to a ranging method, lidar, and computer storage medium. Background Technology
[0002] With the rapid development of lidar technology, lidar applications are becoming increasingly widespread, and the requirements for lidar ranging accuracy are also increasing. However, in close-range, high-reflectivity, and strong backlighting scenarios, the ranging accuracy of lidar may be affected.
[0003] Therefore, how to provide a ranging method that can provide higher ranging accuracy in strong backlighting scenarios is a technical problem that urgently needs to be solved. Summary of the Invention
[0004] This application provides a ranging method, a lidar, and a computer storage medium that can provide higher ranging accuracy in strong backlighting scenarios.
[0005] In a first aspect, a ranging method is provided for use with a lidar, the lidar including a SPAD array, the method comprising: acquiring an echo spot; allocating the echo spot to the SPAD array using a point spread function, the SPAD array including a first energy level region and a second energy level region; wherein the energy intensity of the first energy level region is greater than the energy intensity of the second energy level region; and calculating the target ranging result of the lidar using the echo spot in the first energy level region and / or the second energy level region.
[0006] Based on the above technical solution, the SPAD array can have energy level regions with different energy intensities, thereby realizing the energy gradient setting of the SPAD array. By utilizing the spatial energy distribution difference of the echo spot, SPAD pixel regions with different energy intensities can be allocated, and the SPAD pixel regions used for ranging calculation can be flexibly adjusted. This reduces the impact of the single-bin effect that may be caused by excessively strong photon signals and / or the pile-up effect that may be caused by relatively weak light signals on the ranging accuracy of lidar.
[0007] In conjunction with the first aspect, in some implementations of the first aspect, the target ranging result of the lidar is calculated using the echo spot in the first energy level region and / or the second energy level region, including: when the photon count rate in the first energy level region is below a first threshold, the target ranging result of the lidar is calculated using the echo spot in the first energy level region.
[0008] Based on the above technical solution, when the photon count rate of the first energy level region is within the normal range, the first energy level region located in the center of the SPAD array can be selected by default for ranging to optimize the signal-to-noise ratio.
[0009] In conjunction with the first aspect, some implementations of the first aspect further include: when the photon count rate of the first energy level region exceeds the first threshold, using the echo spot in the first energy level region and the second energy level region to calculate the target ranging result of the lidar; or, when the photon count rate of the first energy level region exceeds the first threshold, using the echo spot in the second energy level region to calculate the target ranging result of the lidar.
[0010] In conjunction with the first aspect, some implementations of the first aspect further include: when the photon count rate of the first energy level region exceeds a first threshold, using the echo spot in the first energy level region and the second energy level region to calculate the target ranging result of the lidar; when the photon count rate of the first energy level region exceeds a second threshold, using the echo spot in the second energy level region to calculate the target ranging result of the lidar.
[0011] Based on the above technical solution, when the photon count rate of the first energy level region is outside the normal range, energy level regions with different energy gradients can be provided to calculate the distance, thereby reducing the impact of excessively strong and / or weak photon signals on the ranging accuracy of the lidar and improving the anti-saturation performance of the lidar.
[0012] In conjunction with the first aspect, in some implementations of the first aspect, the second threshold has multiple values.
[0013] Based on the above technical solution, switching between multiple second-level regions can be achieved.
[0014] In conjunction with the first aspect, in certain implementations of the first aspect, the target ranging result of the lidar is calculated using the echo spot in the first energy level region and / or the second energy level region, including: when the photon count rate of the SPAD array reaches its maximum value, the target ranging result of the lidar is calculated using the echo spot in the first energy level region, the echo spot in the second energy level region, and the sub-spot, wherein the energy intensity of the sub-spot is less than the energy intensity of the echo spot.
[0015] Based on the above technical solution, the ranging accuracy of lidar can be further improved through the collaborative mechanism of the main spot and the secondary spot.
[0016] In conjunction with the first aspect, in some implementations of the first aspect, the SPAD array includes multiple second energy level regions with different energy intensities.
[0017] Based on the above technical solution, the SPAD array can have multiple energy level regions with different energy intensities, thereby realizing diversified energy gradient settings for the SPAD array and improving the versatility of the lidar in different light intensity scenarios.
[0018] In conjunction with the first aspect, in some implementations of the first aspect, the second energy level region is set along the edge of the first energy level region.
[0019] Based on the above technical solution, the lidar can dynamically adjust the energy gradient distribution of different SPAD arrays according to the actual light intensity of the echo spot and the hardware performance of the SPAD array.
[0020] In a second aspect, a lidar is provided, which includes a laser emitter, a processor, and a main control chip. The laser emitter is used to emit a light spot, the processor is used to receive the echo light spot reflected back by the target, and the main control chip is connected to the laser emitter and the processor. The main control chip is used to calculate the target ranging result according to the method provided in the first aspect.
[0021] Thirdly, a computer storage medium is provided, which stores computer program code, and the method provided in the first aspect is executed when the computer program code is run on the computer-readable storage medium. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the system architecture of a lidar 100 provided in an embodiment of this application.
[0023] Figure 2 This is a flowchart illustrating a ranging method 200 provided in an embodiment of this application.
[0024] Figure 3 This is a schematic diagram of a SPAD array in one embodiment of this application.
[0025] Figure 4 This is a schematic diagram of a SPAD array in another embodiment provided in this application.
[0026] Figure 5 This is a schematic diagram of a SPAD array in another embodiment provided in this application.
[0027] Figure 6 This is a schematic diagram of a ranging device 600 provided in an embodiment of this application. Detailed Implementation
[0028] The technical solutions in this application will now be described with reference to the accompanying drawings.
[0029] In the description of the embodiments in this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In this application, "at least one" means one or more, and "more" means two or more.
[0030] The use of prefixes such as "first" and "second" in this application embodiment is solely for distinguishing different descriptive objects and does not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes to distinguish descriptive objects in this application embodiment does not constitute a limitation on the described objects. The description of the described objects is found in the claims or the context of the embodiments, and the use of such prefixes should not constitute unnecessary restrictions.
[0031] To keep the drawings concise, the figures in this application only schematically show the parts related to the corresponding embodiments, and they do not represent the actual structure of the product. In addition, to make the drawings concise and easy to understand, some figures only schematically show some structures or components, and there may actually be more or fewer identical or similar structures or components.
[0032] With the rapid development of lidar technology, lidar applications are becoming increasingly widespread, and the requirements for lidar ranging accuracy are also increasing. Single-photon avalanche diode (SPAD) sensors are widely used in lidar due to their high sensitivity. However, in close-range, high-reflection, and other strong backlighting scenarios, excessively strong echo light may cause the SPAD sensor to continuously saturate, potentially leading to the single-bin effect (when the photon signal is too strong, the number of photons in a slot per unit time period exceeds the counting limit, resulting in signal distortion) and / or the pile-up effect (when the light signal is relatively weak, but more than one photon may still return within a measurement cycle, the detector only records the first arriving photon within a measurement cycle, and subsequent photons are ignored), thus causing lidar ranging nonlinearity or failure.
[0033] In related technologies, the range of photon detection efficiency (PDE) can be adjusted by dynamically changing the laser emission power. However, these technologies suffer from slow response, complex control, and difficulty in covering the full dynamic range. Other related technologies can achieve dynamic range by configuring a SPAD array with dual PDEs (high PDE and low PDE). However, these technologies have limited dynamic range and struggle to handle extreme dynamic values.
[0034] Based on this, this application proposes a ranging method for use with lidar, which includes a SPAD array. The method includes: acquiring echo spots; allocating the echo spots to the SPAD array using a point spread function (PSF), wherein the SPAD array includes a first energy level region and a second energy level region; wherein the energy intensity of the first energy level region is greater than that of the second energy level region; and calculating the target ranging result of the lidar using the echo spots in the first energy level region and / or the second energy level region. The ranging method provided by this application can utilize the spatial energy distribution difference of the echo spots to allocate SPAD pixel regions with different energy intensities, and flexibly adjust the SPAD pixel regions selected for ranging calculation based on the real-time count rate in the SPAD pixel regions, thereby reducing the impact of the single-bin effect that may be caused by excessively strong photon signals and / or the pile-up effect that may be caused by relatively weak light signals on the ranging accuracy of lidar.
[0035] Figure 1 This is a schematic diagram of the system architecture of a lidar 100 provided in an embodiment of this application. The lidar 100 includes a laser emitter 110, a processor 120, and a main control chip 130. The laser emitter 110 is used to emit a light spot, the processor 120 is used to receive the echo light spot reflected back by the target, and the main control chip 130 is connected to the laser emitter 110 and the processor 120. The main control chip 130 is used to calculate the target ranging result.
[0036] In some implementations, processor 120 includes a SPAD array.
[0037] Specifically, a SPAD array can be a matrix of multiple SPAD sensors arranged together.
[0038] In some implementations, the SPAD array includes a first energy level region and a second energy level region; wherein the energy intensity of the first energy level region is greater than the energy intensity of the second energy level region.
[0039] Specifically, echo spots with different energy intensities can exist in the first energy level region (also known as the "central high-energy region") and the second energy level region (also known as the "edge low-energy region").
[0040] The above, combined with Figure 1 The lidar provided in the embodiments of this application is described in detail below. Figures 2 to 5 The methods provided in the embodiments of this application are described in detail. It should be understood that the descriptions of the method embodiments correspond to the descriptions of the system embodiments. Therefore, for content not described in detail, please refer to the above system embodiments. For the sake of brevity, they will not be repeated here.
[0041] Figure 2This is a flowchart illustrating a ranging method 200 provided in an embodiment of this application, applied to... Figure 1 The main control chip 130 in the lidar 100 shown includes: S210, acquire echo spot.
[0042] Specifically, after the laser emitter 110 emits a light spot, the processor 120 acquires the echo light spot reflected back by the target.
[0043] S220 uses a point spread function to distribute the echo spot to a SPAD array, which includes a first energy level region and a second energy level region; wherein the energy intensity of the first energy level region is greater than that of the second energy level region.
[0044] Specifically, the point spread function in the lidar 100 is used to distribute echo spots of different energy intensities to the first energy level region (also known as the "central high energy region") and the second energy level region (also known as the "edge low energy region") located in the SPAD array.
[0045] In some implementations, the SPAD array may have multiple second-level regions with different energy intensities to achieve a multi-energy gradient configuration.
[0046] It should be noted that a SPAD array may include one or more first-level regions and one or more second-level regions. The number of first-level regions and second-level regions in a SPAD array may be the same or different.
[0047] In one possible implementation, the SPAD array can have multiple second energy level regions with different energy intensities, based on each first energy level region. For example, the SPAD array may include first energy level region A, second energy level region B, and second energy level region C, where the energy intensities of the aforementioned energy level regions can satisfy the following order: first energy level region A > second energy level region B > second energy level region C.
[0048] It is understood that the above-mentioned number of second energy level regions and the implementation method of energy intensity gradient sorting are only illustrative examples. The number of second energy level regions with different energy intensities can be two, three, four or other arbitrary numbers. The energy intensities of second energy level regions with different energy intensities can also have different and arbitrary gradient sortings. This application embodiment does not limit this.
[0049] Based on the above technical solution, a SPAD array can have multiple energy level regions with different energy intensities, thereby realizing diversified energy gradient settings for the SPAD array.
[0050] In some implementations, such as Figures 3 to 5 As shown, the second energy level region is set along the edge of the first energy level region.
[0051] In one possible scenario, such as Figure 3 As shown, the SPAD array includes a first energy level region and a second energy level region disposed along the edge of the first energy level region.
[0052] In another possible scenario, such as Figure 4 As shown, the SPAD array includes multiple first energy level regions and second energy level regions arranged along the edge of each first energy level region.
[0053] In another possible scenario, such as Figure 5 As shown, the SPAD array includes multiple first energy level regions and second energy level regions set along the edges of some of the first energy level regions, wherein the edges of some of the first energy level regions may not have second energy level regions set.
[0054] It should be noted that multiple first-level regions can be independent of each other, or they can be in contact with each other, or they can overlap. The above scenarios are only illustrative examples, and the number and / or arrangement of the first and second-level regions are not limited to the above scenarios, and this application does not impose any restrictions on them.
[0055] Based on the above technical solution, the lidar can dynamically adjust the energy gradient distribution of different SPAD arrays according to the actual light intensity of the echo spot and the hardware performance of the SPAD array.
[0056] S230 uses the echo spot in the first energy level region and / or the second energy level region to calculate the target ranging result of the lidar.
[0057] Specifically, such as Figures 3 to 5 As shown, each first energy level region and / or second energy level region can be independently coupled to each time-to-digital converter (TDC) to complete timing in order to complete the calculation of target range.
[0058] Specifically, the target ranging calculation can be completed by selecting one or more echo spots in the first energy level region and / or one or more second energy level regions based on the photon energy intensity and / or photon count rate in the first energy level region, and based on the multiple energy level regions arranged in the SPAD array according to the energy intensity gradient in the foregoing embodiments.
[0059] It should be noted that the number, arrangement, and energy intensity gradient of the first and / or second energy level regions have been described in the foregoing embodiments and will not be repeated here.
[0060] Based on the above technical solution, energy level regions with different energy gradients can be used to calculate the distance, thereby reducing the impact of excessively strong and / or weak photon signals on the ranging accuracy of the lidar and improving the lidar's anti-saturation and anti-pile-up effect performance. Furthermore, using multiple energy level regions with different energy intensities in the aforementioned embodiments to range the target can also improve the versatility of the lidar under different light intensity scenarios.
[0061] In some implementations, when the photon count rate in the first energy level region is below a first threshold, the target ranging result of the lidar is calculated using the echo spot in the first energy level region.
[0062] Specifically, the technical term "photon count rate" can be the number of photons passing through the echo spot per unit measurement time. The photon count rate of the first energy level region can characterize the photon saturation degree of the echo spot in the first energy level region. When the photon count rate of the first energy level region is below a first threshold, it can be indicated that the photon saturation degree in the first energy level region is within the normal range.
[0063] Based on the above technical solution, when the photon count rate of the first energy level region is within the normal range, the first energy level region located in the center of the SPAD array can be selected by default for ranging to optimize the signal-to-noise ratio.
[0064] In some implementations, when the photon count rate in the first energy level region exceeds a first threshold, the target ranging result of the lidar is calculated using the echo spot in the first and second energy level regions; or, when the photon count rate in the first energy level region exceeds the first threshold, the target ranging result of the lidar is calculated using the echo spot in the second energy level region.
[0065] Specifically, when the photon count rate in the first energy level region exceeds the normal range defined by the first threshold, a second energy level region can be gradually and / or directly introduced to use both the first and second energy level regions for ranging, or the system can be directly switched to the second energy level region for ranging.
[0066] It should be noted that when gradually introducing a second energy level region to simultaneously use the first and second energy level regions for ranging, the allocation ratio of the first and second energy level regions can be changed within a unit time, or different allocation ratios of the first and second energy level regions can be selected based on the value of the photon count rate of the first energy level region exceeding the first threshold.
[0067] In some implementations, when the photon count rate in the first energy level region exceeds a first threshold, the target ranging result of the lidar is calculated using the echo spot in the first and second energy level regions; when the photon count rate in the first energy level region exceeds a second threshold, the target ranging result of the lidar is calculated using the echo spot in the second energy level region.
[0068] It's understandable that the second threshold is higher than the first threshold.
[0069] Specifically, when the photon count rate in the first energy level region exceeds the normal range defined by the first threshold (within the second threshold), the second energy level region can be gradually and / or directly introduced to simultaneously use the first and second energy level regions for ranging. When the photon count rate in the first energy level region exceeds the normal range defined by the second threshold, the system completely switches to the second energy level region for ranging.
[0070] In some implementations, there may also be multiple second thresholds.
[0071] As an example, when the SPAD array includes multiple second energy level regions with different energy intensities as described in the foregoing embodiments, one or more thresholds higher than the second threshold (including but not limited to the third threshold, the fourth threshold, etc.) can be set to achieve switching between second energy level regions with different energy intensities.
[0072] It should be noted that the number, arrangement, and implementation of the energy intensity gradient of the second energy level regions with different energy intensities have been described in the aforementioned embodiments and will not be repeated here.
[0073] Based on the above technical solution, when the photon count rate of the first energy level region is outside the normal range, energy level regions with different energy gradients can be provided to calculate the distance, thereby reducing the impact of excessively strong and / or weak photon signals on the ranging accuracy of the lidar and improving the anti-saturation performance of the lidar.
[0074] In some implementations, when the photon counting rate of the SPAD array reaches its maximum value, the target ranging result of the lidar is calculated using the echo spot in the first energy level region, the echo spot in the second energy level region, and the sub-spot, wherein the energy intensity of the sub-spot is less than the energy intensity of the echo spot.
[0075] As an example, when the photon count rate of the entire SPAD array reaches its maximum value (or when the entire SPAD array's spot area is saturated), a secondary spot designed for the lidar optical system can be enabled (as an example, it can be generated by diffractive optical elements). The secondary spot is located far from the echo spot (also known as the main spot), and its energy intensity is several orders of magnitude lower than that of the echo spot.
[0076] Based on the above scheme, the ranging accuracy of lidar can be further improved through the collaborative mechanism of the main spot and the secondary spot.
[0077] The above, combined with Figures 2 to 5 The methods provided in the embodiments of this application are described in detail below. Figure 6 The device provided in the embodiments of this application is described in detail. It should be understood that the description of the device embodiments corresponds to the description of the apparatus embodiments and / or method embodiments. Therefore, for content not described in detail, please refer to the method embodiments above. For the sake of brevity, it will not be repeated here.
[0078] Figure 6 This is a schematic diagram of a ranging device 600 provided in an embodiment of this application.
[0079] like Figure 6 As shown, the ranging device 600 includes a memory 610, a processor 620, and a computer program stored in the memory 610 and executable on the processor 620. When the processor 620 executes the computer program, it implements the method provided in the above embodiments.
[0080] This application also provides a computer-readable storage medium storing computer program code. When the computer program code is executed on the computer-readable storage medium, the computer-readable storage medium performs the above-described embodiments and... Figures 2 to 5 The methods provided in [the document / platform].
[0081] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0082] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.
[0083] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.
[0084] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0085] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.
[0086] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0087] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A method of ranging, characterized by, The method is applied to a lidar system, the lidar system comprising a SPAD array, and the method includes: Acquire echo spot; The echo spot is distributed to the SPAD array using a point spread function. The SPAD array includes a first energy level region and a second energy level region; wherein the energy intensity of the first energy level region is greater than the energy intensity of the second energy level region. The target ranging result of the lidar is calculated using the echo spot in the first energy level region and / or the second energy level region.
2. The method according to claim 1, characterized in that, The step of using the echo spot in the first energy level region and / or the second energy level region to calculate the target ranging result of the lidar includes: When the photon count rate in the first energy level region is below a first threshold, the target ranging result of the lidar is calculated using the echo spot in the first energy level region.
3. The method according to claim 2, characterized in that, Also includes: When the photon count rate in the first energy level region exceeds the first threshold, the target ranging result of the lidar is calculated using the echo spots in the first and second energy level regions, or... When the photon count rate in the first energy level region exceeds the first threshold, the target ranging result of the lidar is calculated using the echo spot in the second energy level region.
4. The method according to claim 2, characterized in that, Also includes: When the photon count rate in the first energy level region exceeds the first threshold, the target ranging result of the lidar is calculated using the echo spot in the first energy level region and the second energy level region. When the photon count rate in the first energy level region exceeds the second threshold, the target ranging result of the lidar is calculated using the echo spot in the second energy level region.
5. The method according to claim 4, characterized in that, The second threshold has multiple values.
6. The method according to any one of claims 1-5, characterized in that, The step of using the echo spot in the first energy level region and / or the second energy level region to calculate the target ranging result of the lidar includes: When the photon counting rate of the SPAD array reaches its maximum value, the target ranging result of the lidar is calculated using the echo spot in the first energy level region, the echo spot in the second energy level region, and the sub-spot, wherein the energy intensity of the sub-spot is less than the energy intensity of the echo spot.
7. The method according to any one of claims 1-6, characterized in that, The SPAD array includes multiple second energy level regions with different energy intensities.
8. The method according to any one of claims 1-7, characterized in that, The second energy level region is set along the edge of the first energy level region.
9. A lidar, characterized in that, The lidar includes a laser emitter, a processor, and a main control chip. The laser emitter is used to emit a light spot, the processor is used to receive the echo light spot reflected back by the target, and the main control chip is connected to the laser emitter and the processor. The main control chip is used to calculate the target ranging result according to any one of claims 1-8.
10. A computer storage medium, characterized in that, The computer-readable storage medium stores computer program code that, when executed on the computer-readable storage medium, performs the method as described in any one of claims 1-8.