Denoising methods, devices, terminal equipment and storage media for lidar

Abstract

This application relates to the field of radar technology and provides a noise reduction method, apparatus, terminal device, and storage medium for lidar. The method includes: when sunlight noise exists in the current detection environment, detecting the first echo reflected from the detection area corresponding to the lidar using a first threshold voltage; when sunlight noise does not exist in the current detection environment, detecting the first echo using a second threshold voltage, wherein the second threshold voltage is lower than the first threshold voltage. Therefore, by using a high threshold voltage to detect the echo when sunlight noise is present to filter out sunlight noise, and using a low threshold voltage to detect the echo when sunlight noise is absent, the accuracy of echo detection is ensured. This not only removes sunlight noise and improves the reliability of point cloud data, but also eliminates the need for subsequent processing of point cloud data by directly removing sunlight noise during the echo signal extraction stage, resulting in low computational complexity and saving chip computing resources.

Description

Technical Field

[0001] This application belongs to the field of radar technology, and in particular relates to a noise reduction method, device, terminal equipment and computer-readable storage medium for lidar. Background Technology

[0002] With the rise of lidar and millimeter-wave radar, various radar devices have been widely used in robots, vehicles, and other equipment for ranging, target detection, and other tasks. For example, lidar can measure the propagation distance between a laser emitter and a target object, and analyze information such as the magnitude of reflected energy, amplitude, frequency, and phase of the reflected spectrum on the target object's surface, thereby revealing precise three-dimensional structural information of the target object.

[0003] In lidar, silicon photomultiplier tubes (SiPMs) are typically used as the receiving sensor. They are characterized by high receiving sensitivity, but are easily affected by ambient light (mainly sunlight), resulting in a low signal-to-noise ratio in the echo data acquired by the lidar, which in turn affects the detection accuracy of the lidar.

[0004] In related technologies, sunlight noise in point cloud data is usually removed through algorithmic models. However, this also removes some points of actual objects, which not only affects the reliability of the point cloud data, but also has high computational complexity and consumes a lot of computing resources. Summary of the Invention

[0005] This application provides a method, apparatus, terminal device, and computer-readable storage medium for denoising LiDAR. It can solve the problem that removing sunlight noise from point cloud data through algorithm models will remove some points of actual objects, which will not only affect the reliability of point cloud data, but also result in high computational complexity and high computational resource consumption.

[0006] In a first aspect, embodiments of this application provide a noise reduction method for a lidar, comprising: when sunlight noise exists in the current detection environment, using a first threshold voltage to detect the first echo reflected from the detection area corresponding to the lidar; and when sunlight noise does not exist in the current detection environment, using a second threshold voltage to detect the first echo, wherein the second threshold voltage is less than the first threshold voltage.

[0007] In one possible implementation of the first aspect, before detecting the first echo reflected from the detection area corresponding to the lidar using a first threshold voltage when sunlight noise exists in the current detection environment, the method further includes:

[0008] The driving voltage of the SiPM in the lidar is reduced from a first voltage value to a second voltage value, and after a first preset time, the driving voltage of the SiPM is increased back to the first voltage value.

[0009] The second echo reflected from the detection area is detected using a second threshold voltage.

[0010] If a second echo is detected, it is determined that there is sunlight noise in the current detection environment;

[0011] If no second echo is detected, it is determined that there is no sunlight noise in the current detection environment.

[0012] Optionally, in another possible implementation of the first aspect, the first preset duration is determined based on the difference between the first voltage value and the second voltage value and the hardware parameters of the SiPM.

[0013] Optionally, in another possible implementation of the first aspect, before detecting the first echo reflected from the detection area corresponding to the lidar using the first threshold voltage, the method further includes:

[0014] Keep the driving voltage of SiPM at the first voltage value.

[0015] Optionally, in another possible implementation of the first aspect, before detecting the first echo using the second threshold voltage, the method further includes:

[0016] Control the laser emitter in the lidar to emit a laser beam into the detection area;

[0017] The driving voltage of the SiPM is reduced from a first voltage value to a second voltage value, and then increased back to the first voltage value after a second preset time.

[0018] Optionally, in another possible implementation of the first aspect, the aforementioned second preset duration is determined based on the difference between the first voltage value and the second voltage value, the hardware parameters of the SiPM, and the propagation time of the laser beam inside the lidar.

[0019] Optionally, in another possible implementation of the first aspect, before detecting the first echo reflected from the detection area corresponding to the lidar using the first threshold voltage, the method further includes:

[0020] Control the laser emitter in the lidar to emit a laser beam into the detection area.

[0021] Secondly, embodiments of this application provide a noise reduction device for a lidar, comprising: a first detection module, configured to detect a first echo reflected from the detection area corresponding to the lidar using a first threshold voltage when sunlight noise exists in the current detection environment; and a second detection module, configured to detect the first echo using a second threshold voltage when sunlight noise does not exist in the current detection environment, wherein the second threshold voltage is less than the first threshold voltage.

[0022] In one possible implementation of the second aspect, the above-mentioned apparatus further includes:

[0023] The first voltage adjustment module is used to reduce the driving voltage of the SiPM in the lidar from a first voltage value to a second voltage value, and after a first preset time, increase the driving voltage of the SiPM back to the first voltage value.

[0024] The third detection module is used to detect the second echo reflected from the detection area using a second threshold voltage.

[0025] The first determining module is used to determine that there is sunlight noise in the current detection environment if a second echo is detected.

[0026] The second determining module is used to determine that there is no sunlight noise in the current detection environment if no second echo is detected.

[0027] Optionally, in another possible implementation of the second aspect, the first preset duration is determined based on the difference between the first voltage value and the second voltage value and the hardware parameters of the SiPM.

[0028] Optionally, in another possible implementation of the second aspect, the above-mentioned apparatus further includes:

[0029] The first holding module is used to maintain the driving voltage of the SiPM at a first voltage value.

[0030] Optionally, in another possible implementation of the second aspect, the above-mentioned apparatus further includes:

[0031] The first transmitting module is used to control the laser transmitter in the lidar to emit a laser beam into the detection area;

[0032] The second voltage adjustment module is used to reduce the driving voltage of the SiPM from a first voltage value to a second voltage value, and then increase it back to the first voltage value after a second preset time.

[0033] Optionally, in another possible implementation of the second aspect, the aforementioned second preset duration is determined based on the difference between the first voltage value and the second voltage value, the hardware parameters of the SiPM, and the propagation time of the laser beam inside the lidar.

[0034] Optionally, in another possible implementation of the second aspect, the above-mentioned apparatus further includes:

[0035] The second transmitting module is used to control the laser transmitter in the lidar to emit a laser beam into the detection area.

[0036] Thirdly, embodiments of this application provide a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the denoising method for the lidar as described above.

[0037] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned denoising method for lidar.

[0038] Fifthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the aforementioned denoising method for LiDAR.

[0039] The beneficial effects of this application embodiment compared with the prior art are as follows: by using a high threshold voltage to detect the echo when sunlight noise is present to filter out sunlight noise, and using a low threshold voltage to detect the echo when sunlight noise is absent, the accuracy of echo detection is ensured while filtering out sunlight noise. This not only removes sunlight noise and improves the reliability of point cloud data, but also removes sunlight noise directly in the echo signal extraction stage, eliminating the need for subsequent processing of point cloud data, resulting in low computational complexity and saving chip computing resources. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic flowchart of a denoising method for a lidar provided in an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of an echo waveform provided in an embodiment of this application;

[0043] Figure 3 This is a waveform diagram of multiple sets of echoes with sunlight noise superimposed after the driving voltage of SiPM is increased from a second voltage value to a first voltage value according to an embodiment of this application;

[0044] Figure 4 This is a schematic diagram of the structure of the noise reduction device for lidar provided in the embodiments of this application;

[0045] Figure 5 This is a schematic diagram of the structure of the terminal device provided in the embodiments of this application. Detailed Implementation

[0046] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0047] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0048] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0049] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0050] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0052] The following description, with reference to the accompanying drawings, details the noise reduction method, apparatus, terminal device, storage medium, and computer program for the lidar provided in this application.

[0053] Figure 1 The diagram shows a flowchart of a noise reduction method for lidar provided in an embodiment of this application.

[0054] like Figure 1 As shown, the noise reduction method for this lidar includes the following steps:

[0055] Step 101: When there is sunlight noise in the current detection environment, the first echo reflected by the detection area corresponding to the lidar is detected using the first threshold voltage.

[0056] It should be noted that the denoising method of the lidar in this application embodiment can be executed by the lidar denoising device of this application embodiment. The lidar denoising device of this application embodiment can be configured in any terminal device to execute the lidar denoising method of this application embodiment. For example, the lidar denoising device of this application embodiment can be configured in the processing unit of the lidar to control the signal transmission and signal reception process of the lidar and improve the quality of the echo data.

[0057] The current detection environment can refer to the current working environment of the lidar. For example, the current detection environment of the lidar can be indoors, outdoors, a strong light environment, or a weak light environment, etc. This application embodiment does not limit this.

[0058] The first threshold voltage can refer to a higher threshold voltage used when detecting echo waveforms in a detection environment with sunlight noise.

[0059] For example, such as Figure 2The diagram shown is a schematic of an echo waveform provided in an embodiment of this application. In the diagram, start is the leading edge value of the echo waveform, stop is the trailing edge value of the echo waveform, and the dashed line is used to represent the threshold voltage for detecting the echo. It can be seen that if there is a pulse with a voltage value greater than the threshold voltage in the signal received by the lidar, the pulse can be identified as an echo, and the waveform between the detected leading edge value and the corresponding trailing edge value can be identified as an echo.

[0060] The detection area corresponding to the lidar can refer to the area that the lidar can currently detect.

[0061] The first echo can refer to the echo extracted from the received signal (the signal reflected back from the object in the detection area) after the lidar emits a laser beam.

[0062] In this embodiment, if it is determined that sunlight noise exists in the current detection environment, such as being under direct sunlight or having other strong light sources, then when the lidar receives the echo signal, the echo signal will contain not only the reflected light corresponding to the laser beam reflected back from the object in the detection area (i.e., the first echo), but also sunlight noise. Since the voltage value of sunlight noise is typically low, while the voltage value of a normal echo waveform under sunlight is typically high, a higher first threshold voltage can be used to detect the first echo. Figure 2 The threshold voltage shown is determined as the first threshold voltage, so that all such threshold voltages in the echo signal are... Figure 2 The echo waveforms shown can all be detected as echo waveforms and used for subsequent point cloud data generation; while all echo signals that do not meet the criteria... Figure 2 Waveforms that are related to the first threshold voltage will be filtered out, thus filtering out sunlight noise.

[0063] It should be noted that in actual use, the specific value of the first threshold voltage can be determined according to actual needs and specific application scenarios, or the specific value of the first threshold voltage can be determined through experiments. This application embodiment does not limit this.

[0064] One possible implementation is to place a light sensor inside or near the lidar to detect the light intensity of the current detection environment, and then determine whether sunlight noise exists in the current detection environment based on the light intensity. As an example, if the light intensity of the current detection environment is greater than or equal to a light intensity threshold, it can be determined that sunlight noise exists in the current detection environment; if the light intensity of the current detection environment is less than the light intensity threshold, it can be determined that sunlight noise does not exist in the current detection environment.

[0065] Furthermore, to improve the accuracy of determining whether sunlight noise exists in the current detection environment, the presence of sunlight noise can be detected using a SiPM in the lidar, thereby further improving the reliability of sunlight noise removal. That is, in one possible implementation of this application, before step 101 above, the following may also be included:

[0066] The driving voltage of the SiPM in the lidar is reduced from a first voltage value to a second voltage value, and after a first preset time, the driving voltage of the SiPM is increased back to the first voltage value.

[0067] The second echo reflected from the detection area is detected using a second threshold voltage.

[0068] If a second echo is detected, it is determined that there is sunlight noise in the current detection environment;

[0069] If no second echo is detected, it is determined that there is no sunlight noise in the current detection environment.

[0070] The first voltage value can refer to the driving voltage value that enables the SiPM to have good detection sensitivity to optical signals.

[0071] The second voltage value can refer to the driving voltage value that prevents the SiPM from properly detecting optical signals.

[0072] It should be noted that the first voltage value is greater than the second voltage value. In actual use, the specific values ​​of the first and second voltage values ​​can be determined according to the actual performance of the SiPM used in the lidar, and this application embodiment does not limit this.

[0073] The second threshold voltage can refer to a lower threshold voltage used for detecting echo waveforms; and the second threshold voltage is less than the first threshold voltage.

[0074] It should be noted that even if sunlight noise exists in the current detection environment, the voltage value of the pulse corresponding to the sunlight noise in the echo is relatively small. Therefore, the second threshold voltage can be set to a small value to reliably detect the sunlight noise in the current detection environment. This prevents the second threshold voltage from being set too high, which could lead to the missed detection of the echo waveform corresponding to the sunlight noise and thus cause an error in the classification of the current detection environment.

[0075] The second echo can refer to the echo detected from the signal received by the lidar before each laser beam is emitted, i.e., the echo corresponding to sunlight noise.

[0076] As one possible implementation, since the lower the driving voltage of the SiPM, the lower the detection sensitivity of the optical signal, and the higher the driving voltage of the SiPM, the higher the detection sensitivity of the optical signal, and after lowering and then raising the driving voltage of the SiPM, the driving voltage of the SiPM will oscillate, resulting in the driving voltage value of the SiPM being slightly higher than the first voltage value for a short period of time after the driving voltage of the SiPM rises to the first voltage value. This allows for higher detection sensitivity of the optical signal for a short period of time after the driving voltage of the SiPM rises to the first voltage value, thereby enabling reliable detection of sunlight noise with low voltage values.

[0077] Therefore, in this embodiment, before each laser beam emission, the driving voltage of the SiPM can be reduced from a first voltage value to a second voltage value, and after a preset time, the driving voltage of the SiPM can be increased back to the first voltage value. Then, the SiPM is driven to perform echo detection using a lower second threshold. If a second echo reflected within the detection area is detected, it can be determined that sunlight noise exists in the current detection environment; if no second echo is detected, it can be determined that sunlight noise does not exist in the current detection environment.

[0078] It should be noted that, as Figure 3 The diagram shown is a waveform diagram of multiple sets of echoes with sunlight noise superimposed after the driving voltage of the SiPM is increased from the second voltage value to the first voltage value according to an embodiment of this application. It can be seen that after the driving voltage of the SiPM is first reduced to the second voltage value and then increased to the first voltage value, an echo waveform 301 corresponding to obvious sunlight noise can be detected, thus proving the effectiveness of the method of this embodiment of the application in detecting sunlight noise.

[0079] As one possible implementation, the first preset duration can be determined based on the difference between the first voltage value and the second voltage value and the hardware parameters of the SiPM.

[0080] Understandably, in practical applications, after the SiPM's driving voltage is reduced or increased, the SiPM's driving voltage value does not immediately decrease or increase to the target voltage value, but rather there is a certain time delay. This specific time delay is related to the adjusted voltage amplitude and the SiPM's hardware parameters. Therefore, before increasing the SiPM's driving voltage to the first voltage value, it is necessary to ensure that the SiPM's driving voltage has already decreased to the second voltage value. Thus, based on the difference between the first and second voltage values ​​and the SiPM's hardware parameters, the time delay for the driving voltage to decrease from the first voltage value to the second voltage value can be determined. Subsequently, the first preset duration can be determined as any duration greater than this delay.

[0081] It should be noted that, since the scanning frequency of the lidar is relatively high, in order to ensure that sunlight noise does not affect the detection of each laser emission, the first preset duration can be set to a small value. For example, if the delay of the SiPM's driving voltage decreasing from the first voltage value to the second voltage value is 40ns, the first preset duration can be determined to be 50ns, 100ns, 200ns, etc., and this application does not limit this.

[0082] Furthermore, in the presence of sunlight noise in the current detection environment, the driving voltage of the SiPM can be kept at a high level to ensure the detection sensitivity of the SiPM. That is, in one possible implementation of this application embodiment, before step 101 above, the following may be included:

[0083] Keep the driving voltage of SiPM at the first voltage value.

[0084] In this embodiment, a portion of the laser beam emitted by the lidar is reflected within the lidar, forming stray light. Furthermore, due to the wide pulse width of this stray light, it easily overlaps with echo pulses reflected from nearby objects, making it impossible to properly identify the echoes from these objects, thus affecting point cloud quality and lidar detection accuracy. However, when sunlight noise is present in the current detection environment (i.e., when the second echo corresponding to the sunlight noise can be detected through the aforementioned steps), it usually indicates that there are no objects near the lidar that can block sunlight, meaning there are no actual objects nearby. Therefore, in the presence of sunlight noise in the current detection environment, stray light will not affect normal object detection, i.e., it will not affect point cloud quality. Therefore, in the presence of sunlight noise in the current detection environment, the influence of stray light on echo detection can be disregarded, and the SiPM's driving voltage can be directly maintained at a high first voltage value to ensure the SiPM's detection sensitivity. This not only eliminates the influence of sunlight noise and stray light on point cloud quality, improving point cloud quality, but also eliminates the need to adjust the SiPM's driving voltage, further reducing resource consumption.

[0085] Furthermore, since the laser beam emitted by the lidar is periodic, and the lidar is typically moving during operation, or the object being detected is moving, the detection environment of the lidar is usually changing in real time. Therefore, to ensure the reliability of sunlight noise removal, the presence of sunlight noise in the current detection environment can be determined before each laser beam emission. The laser beam is then emitted only after the determination is completed and an echo detection strategy is determined. That is, in one possible implementation of this application embodiment, before step 101 above, the following may also be included:

[0086] Control the laser emitter in the lidar to emit a laser beam into the detection area.

[0087] The laser emitter can be any type of device capable of generating laser light, and this application does not limit this. For example, the laser emitter can be a laser diode (LD).

[0088] As one possible implementation, the presence of sunlight noise in the current detection environment can be determined before each laser beam is emitted. After the determination is completed and the echo detection strategy is determined, the laser emitter in the lidar is controlled to emit a laser beam, and then the SiPM is driven to detect the first echo with a first threshold voltage.

[0089] Step 102: When there is no sunlight noise in the current detection environment, the first echo is detected using a second threshold voltage, wherein the second threshold voltage is less than the first threshold voltage.

[0090] In this embodiment, if it is determined that there is no sunlight noise in the current detection environment according to any of the aforementioned steps, the first echo can be detected with a lower second threshold voltage. Since there is no sunlight noise in the echo signal at this time, there is no need to consider filtering out sunlight noise. Therefore, the first echo can be detected with a lower threshold voltage to ensure the detection accuracy of the first echo reflected by the actual object in the detection area as much as possible, so as to prevent the first echo emitted by the actual object from being missed.

[0091] Furthermore, since there is no sunlight noise in the current detection environment, i.e., no second echo corresponding to sunlight noise is detected through the aforementioned steps, it usually indicates that there may be an object blocking sunlight near the lidar, i.e., there may be an actual object at close range. Therefore, in the absence of sunlight noise in the current detection environment, stray light may affect normal object detection, thereby reducing point cloud quality. Therefore, in the absence of sunlight noise in the current detection environment, the influence of stray light on echo detection can be removed to further improve point cloud quality. That is, in one possible implementation of the embodiments of this application, before step 102 above, it may also include:

[0092] Control the laser emitter in the lidar to emit a laser beam into the detection area;

[0093] The driving voltage of the SiPM is reduced from a first voltage value to a second voltage value, and then increased back to the first voltage value after a second preset time.

[0094] One possible approach is to determine the presence of sunlight noise in the current detection environment before each laser beam emission. After this determination and the establishment of an echo detection strategy, the laser emitter in the lidar is controlled to emit the laser beam, and then the SiPM is driven to detect the first echo. However, because the echo pulse of stray light has a wide pulse width, it easily overlaps with the echo pulse of nearby objects, thus affecting the detection accuracy of nearby objects. Therefore, after driving the laser emitter to emit the laser beam, the driving voltage of the SiPM can be immediately adjusted so that the SiPM cannot receive the echo corresponding to the stray light.

[0095] It is understandable that, since stray light is light reflected from within the lidar, the SiPM receives the echo corresponding to the stray light earlier than it receives the echo reflected from the actual object in the detection area. Therefore, after emitting the laser beam, the SiPM can be temporarily unable to receive the echo, and after a period of time, it can resume normal echo reception, thus preventing the SiPM from receiving the echo corresponding to the stray light and removing stray light during the signal reception stage. Therefore, immediately after the laser emitter emits the laser beam, the SiPM's driving voltage can be reduced from a first voltage value to a second voltage value to decrease the SiPM's detection sensitivity, preventing it from receiving the echo corresponding to the stray light; and after a second preset time, the SiPM's driving voltage can be increased from the second voltage value to the first voltage value, allowing the SiPM to return to normal detection sensitivity after the second preset time and receive the first echo reflected from the actual object in the detection area.

[0096] As one possible implementation, the second preset duration can be determined based on the difference between the first voltage value and the second voltage value, the hardware parameters of the SiPM, and the propagation time of the laser beam inside the lidar.

[0097] The propagation time of the laser beam inside the lidar can refer to the time between the emission of the laser beam and the moment when the SiPM receives the echo generated by the reflection of the laser beam inside the lidar.

[0098] Understandably, in practical applications, after lowering or raising the SiPM's driving voltage, the SiPM's driving voltage value does not immediately decrease or increase to the target voltage value; rather, there is a certain time delay. This specific time delay is related to the adjusted voltage amplitude and the SiPM's hardware parameters. Therefore, before raising the SiPM's driving voltage to the first voltage value, it is necessary to ensure that the SiPM's driving voltage has already decreased to the second voltage value. Furthermore, since the reason for lowering the SiPM's driving voltage value to the second voltage value is to prevent the SiPM from receiving echoes corresponding to stray light, the second preset duration should be greater than or equal to the propagation time of the laser beam inside the lidar, to ensure that the SiPM's driving voltage value remains at the second voltage value before stray light propagates to the SiPM.

[0099] Therefore, based on the difference between the first voltage value and the second voltage value and the hardware parameters of the SiPM, the time delay of the driving voltage decreasing from the first voltage value to the second voltage value can be determined, and the larger value between this time delay and the propagation time of the laser beam inside the lidar can be determined. Then, the second preset duration can be determined to be a duration greater than or equal to and close to the larger value, so as to prevent the missed detection of echoes reflected by actual objects while filtering out stray light, thereby further improving the accuracy of echo detection and point cloud quality.

[0100] For example, assuming the time delay for reducing the SiPM's driving voltage from a first voltage value to a second voltage value is 40ns, and the propagation time of the laser beam inside the lidar is 60ns, then the second preset duration can be determined as 60ns, 61ns, 65ns, 100ns, etc.; if the propagation time of the laser beam inside the lidar is 30ns, then the second preset duration can be determined as 40ns, 41ns, 50ns, 60ns, etc.

[0101] It should be noted that the above examples are merely illustrative and should not be considered as limitations on this application. In actual use, the specific value of the second preset duration can be determined according to actual needs and specific application scenarios, and this application embodiment does not limit this.

[0102] The denoising method for lidar provided in this application involves detecting the first echo reflected from the detection area corresponding to the lidar using a first threshold voltage when sunlight noise is present in the current detection environment, and detecting the first echo using a second threshold voltage lower than the first threshold voltage when sunlight noise is absent. Thus, by using a high threshold voltage to detect the echo when sunlight noise is present to filter it out, and using a low threshold voltage to detect the echo when sunlight noise is absent, the accuracy of echo detection is maintained while filtering out sunlight noise. This not only removes sunlight noise and improves the reliability of point cloud data, but also eliminates the need for subsequent processing of point cloud data by directly removing sunlight noise during the echo signal extraction stage, resulting in low computational complexity and saving chip computing resources.

[0103] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0104] Corresponding to the denoising method for lidar described in the above embodiments, Figure 4 A schematic diagram of the structure of the noise reduction device for lidar provided in the embodiments of this application is shown. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0105] Reference Figure 4 The device 40 includes:

[0106] The first detection module 41 is used to detect the first echo reflected from the detection area corresponding to the lidar by using a first threshold voltage when there is sunlight noise in the current detection environment.

[0107] The second detection module 42 is used to detect the first echo using a second threshold voltage when there is no sunlight noise in the current detection environment, wherein the second threshold voltage is less than the first threshold voltage.

[0108] In practical use, the denoising device for lidar provided in this application embodiment can be configured in any terminal device to execute the aforementioned lidar denoising method.

[0109] The denoising device for lidar provided in this application detects the first echo reflected from the detection area corresponding to the lidar using a first threshold voltage when sunlight noise is present in the current detection environment, and detects the first echo using a second threshold voltage lower than the first threshold voltage when sunlight noise is absent. Thus, by using a high threshold voltage to detect the echo when sunlight noise is present to filter it out, and using a low threshold voltage to detect the echo when sunlight noise is absent, the accuracy of echo detection is maintained while filtering out sunlight noise. This not only removes sunlight noise and improves the reliability of point cloud data, but also eliminates the need for subsequent processing of point cloud data by directly removing sunlight noise during the echo signal extraction stage, resulting in low computational complexity and saving chip computing resources.

[0110] In one possible implementation of this application, the aforementioned device 40 further includes:

[0111] The first voltage adjustment module is used to reduce the driving voltage of the SiPM in the lidar from a first voltage value to a second voltage value, and after a first preset time, increase the driving voltage of the SiPM back to the first voltage value.

[0112] The third detection module is used to detect the second echo reflected from the detection area using a second threshold voltage.

[0113] The first determining module is used to determine that there is sunlight noise in the current detection environment if a second echo is detected.

[0114] The second determining module is used to determine that there is no sunlight noise in the current detection environment if no second echo is detected.

[0115] Optionally, in another possible implementation of the second aspect, the first preset duration is determined based on the difference between the first voltage value and the second voltage value and the hardware parameters of the SiPM.

[0116] Optionally, in another possible implementation of the second aspect, the aforementioned device 40 further includes:

[0117] The first holding module is used to maintain the driving voltage of the SiPM at a first voltage value.

[0118] Optionally, in another possible implementation of the second aspect, the aforementioned device 40 further includes:

[0119] The first transmitting module is used to control the laser transmitter in the lidar to emit a laser beam into the detection area;

[0120] The second voltage adjustment module is used to reduce the driving voltage of the SiPM from a first voltage value to a second voltage value, and then increase it back to the first voltage value after a second preset time.

[0121] Optionally, in another possible implementation of the second aspect, the aforementioned second preset duration is determined based on the difference between the first voltage value and the second voltage value, the hardware parameters of the SiPM, and the propagation time of the laser beam inside the lidar.

[0122] Optionally, in another possible implementation of the second aspect, the aforementioned device 40 further includes:

[0123] The second transmitting module is used to control the laser transmitter in the lidar to emit a laser beam into the detection area.

[0124] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0125] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments 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. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0126] To implement the above embodiments, this application also proposes a terminal device.

[0127] Figure 5 This is a schematic diagram of the structure of a terminal device according to an embodiment of this application.

[0128] like Figure 5 As shown, the terminal device 200 includes:

[0129] The system includes a memory 210 and at least one processor 220, and a bus 230 connecting different components (including the memory 210 and the processor 220). The memory 210 stores a computer program, which, when executed by the processor 220, implements the denoising method for the lidar described in the embodiments of this application.

[0130] Bus 230 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. Examples of these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0131] Terminal device 200 typically includes various electronically readable media. These media can be any available media that can be accessed by terminal device 200, including volatile and non-volatile media, removable and non-removable media.

[0132] Memory 210 may also include computer system readable media in the form of volatile memory, such as random access memory (RAM) 240 and / or cache memory 250. Terminal device 200 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 260 may be used to read and write non-removable, non-volatile magnetic media (…). Figure 5 Not shown; usually referred to as a "hard drive"). Although Figure 5 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 230 via one or more data media interfaces. Memory 210 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of this application.

[0133] A program / utility 280 having a set (at least one) of program modules 270 may be stored in, for example, memory 210. Such program modules 270 include—but are not limited to—an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 270 typically perform the functions and / or methods described in the embodiments of this application.

[0134] Terminal device 200 can also communicate with one or more external devices 290 (e.g., keyboard, pointing device, display 291, etc.), and with one or more devices that enable a user to interact with terminal device 200, and / or with any device that enables terminal device 200 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed via input / output (I / O) interface 292. Furthermore, terminal device 200 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 293. As shown, network adapter 293 communicates with other modules of terminal device 200 via bus 230. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with terminal device 200, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0135] The processor 220 performs various functional applications and data processing by running programs stored in the memory 210.

[0136] It should be noted that the implementation process and technical principles of the terminal device in this embodiment are explained in the foregoing description of the denoising method of the lidar in the embodiment of this application, and will not be repeated here.

[0137] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0138] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the steps described in the various method embodiments above.

[0139] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographing device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0140] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0141] 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.

[0142] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For instance, the division of modules or 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 displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0143] 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.

[0144] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A noise reduction method for lidar, characterized in that, include: The driving voltage of the silicon photomultiplier tube (SiPM) in the lidar is reduced from a first voltage value to a second voltage value, and after a first preset time, the driving voltage of the SiPM is increased back to the first voltage value. The second echo reflected from the detection area corresponding to the lidar is detected using a second threshold voltage. If the second echo is detected, it is determined that there is sunlight noise in the current detection environment; If the second echo is not detected, it is determined that there is no sunlight noise in the current detection environment; When sunlight noise exists in the current detection environment, the first echo reflected from the detection area corresponding to the lidar is detected using a first threshold voltage. When there is no sunlight noise in the current detection environment, the first echo is detected using the second threshold voltage, wherein the second threshold voltage is less than the first threshold voltage.

2. The method as described in claim 1, characterized in that, The first preset duration is determined based on the difference between the first voltage value and the second voltage value and the hardware parameters of the SiPM.

3. The method as described in claim 1, characterized in that, Before detecting the first echo reflected from the detection area corresponding to the lidar using a first threshold voltage, the method further includes: The driving voltage of the SiPM is kept at the first voltage value.

4. The method as described in claim 1, characterized in that, Before detecting the first echo using the second threshold voltage, the method further includes: Control the laser emitter in the lidar to emit a laser beam into the detection area; The driving voltage of the SiPM is reduced from the first voltage value to the second voltage value, and then increased back to the first voltage value after a second preset time.

5. The method as described in claim 4, characterized in that, The second preset duration is determined based on the difference between the first voltage value and the second voltage value, the hardware parameters of the SiPM, and the propagation time of the laser beam inside the lidar.

6. The method according to any one of claims 1-5, characterized in that, Before detecting the first echo reflected from the detection area corresponding to the lidar using a first threshold voltage, the method further includes: The laser emitter in the lidar is controlled to emit a laser beam into the detection area.

7. A noise reduction device for lidar, characterized in that, include: The first voltage adjustment module is used to reduce the driving voltage of the silicon photomultiplier tube (SiPM) in the lidar from a first voltage value to a second voltage value, and after a first preset time, increase the driving voltage of the SiPM back to the first voltage value. The third detection module is used to detect the second echo reflected from the detection area corresponding to the lidar using a second threshold voltage. The first determining module is used to determine that there is sunlight noise in the current detection environment if the second echo is detected; The second determining module is used to determine that there is no sunlight noise in the current detection environment if the second echo is not detected. The first detection module is used to detect the first echo reflected from the detection area corresponding to the lidar by using a first threshold voltage when there is sunlight noise in the current detection environment. The second detection module is used to detect the first echo using the second threshold voltage when there is no sunlight noise in the current detection environment, wherein the second threshold voltage is less than the first threshold voltage.

8. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-6.

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