Echo extraction method, device and equipment of laser radar and storage medium

Abstract

The invention discloses an echo extraction method, device and equipment of a laser radar, and a storage medium, relates to the technical field of signal processing, and aims to solve the problem that the detection result of a laser radar sensor is inaccurate due to the existence of high-reflectivity expansion false echoes in the detection result when a high-reflectivity object appears in the field of view of the laser radar in the related technology. The echo extraction method of the laser radar comprises the following steps: acquiring an echo signal of the laser radar, wherein the echo signal comprises at least one echo; determining an effective echo intensity threshold value of the echo signal based on the characteristics of each echo in the echo signal; and determining a real echo from at least one echo of the echo signal based on the characteristics of each echo in the echo signal, the effective echo intensity threshold and the high-reflectivity target echo distance range.

Description

Technical Field

[0001] This application relates to the field of signal processing technology, and in particular to a method, apparatus, device and storage medium for echo extraction of lidar. Background Technology

[0002] LiDAR is a crucial sensor in current vehicle autonomous driving systems. Compared to other sensors, LiDAR boasts advantages such as high reliability, long detection range, and strong detail resolution. LiDAR operates on the principle of direct time-of-flight (dToF) ranging. Essentially, it determines distance by sending a laser pulse and using the internal signal processing components to determine the time required for the pulse to return. To increase the information content of a single LiDAR frame, i.e., point cloud density, most LiDAR systems control multiple laser transmitters and receivers to simultaneously perform ranging. This increases point cloud density while maintaining the refresh rate of the LiDAR point cloud. However, this transmission and reception method can lead to the detection of highly reflective objects within the field of view, resulting in false echoes and preventing the output of accurate object information, thus reducing the accuracy of the LiDAR sensor. Summary of the Invention

[0003] The purpose of this application is to provide a method, apparatus, device, and storage medium for extracting echoes from a lidar, aiming to solve the problem in the related art where, when a highly reflective object appears in the field of view of the lidar, there are false echoes due to high reflectivity expansion in the detection results, leading to inaccurate detection results of the lidar sensor.

[0004] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0005] In a first aspect, embodiments of this application provide a method for echo extraction from a lidar system, the method comprising:

[0006] Acquire the echo signal of the lidar, the echo signal including at least one echo;

[0007] Based on the characteristics of each echo in the echo signal, the effective echo intensity threshold of the echo signal is determined.

[0008] Based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of high-reflection targets, the true echo is determined from at least one echo in the echo signal.

[0009] The lidar echo extraction method provided in this application processes at least one echo in the echo signal by analyzing the characteristics of each echo, the effective echo intensity threshold, and the echo range of high-reflectivity targets. This filters out high-reflectivity expanded echoes and retains the true echoes, enabling the lidar to output more reliable and complete detection information. Furthermore, this lidar echo extraction method is applicable to most lidar systems and different lidar systems, exhibiting strong adaptability and robustness. Additionally, this application does not rely on additional hardware control circuits or optical crosstalk suppression modules, resulting in low cost, low complexity, and high versatility.

[0010] In some embodiments, determining the true echo from at least one echo of the echo signal based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of the high-reflection target includes: determining the echo in the echo signal with a signal intensity greater than the effective echo intensity threshold as the first echo; and determining the true echo from the first echo based on the characteristics of the first echo and the echo distance range of the high-reflection target.

[0011] In some embodiments, determining the true echo from at least one first echo based on the characteristics of the first echo in the echo signal and the distance range of the high-reflection target echo includes: if no first echo in the echo signal has a distance within the distance range of the high-reflection target echo, taking the first echo with the closest distance in the echo signal as the true echo.

[0012] In some embodiments, determining the true echo from the first echo based on the characteristics of the first echo in the echo signal and the distance range of the high-reflection target echo includes: if there is a first echo in the echo signal whose distance is within the distance range of the high-reflection target echo, and there is only one first echo in the echo signal, and if the signal strength of the first echo is greater than the intensity threshold of the true object, then the first echo is determined to be the true echo.

[0013] In some embodiments, the real object intensity threshold is greater than the effective echo intensity threshold.

[0014] In some embodiments, determining the true echo from the first echo based on the characteristics of the first echo and the distance range of the high-reflection target echo includes: if there are multiple first echoes in the echo signal, and at least one of the multiple first echoes is within the distance range of the high-reflection target echo, and if the signal strength of all the first echoes within the distance range of the high-reflection target echo is less than or equal to the first high-reflection target strength threshold, then the first echo with the closest distance in the echo signal is taken as the true echo.

[0015] In some embodiments, determining the true echo from the first echo based on the characteristics of the first echo in the echo signal and the distance range of the high-reflection target echo includes: when there are multiple first echoes in the echo signal, and at least one of the multiple first echoes has a distance within the distance range of the high-reflection target echo, determining the first echo among the multiple first echoes whose distance is within the distance range of the high-reflection target echo and whose signal strength is greater than a first high-reflection target strength threshold as the second echo; and determining the true echo from the second echo based on the characteristics of the second echo.

[0016] In some embodiments, determining the true echo from the second echo based on the characteristics of the second echo includes: determining the second echo with the highest signal strength among the second echoes that meet the high-reflection target judgment conditions as the true echo. The high-reflection target judgment conditions include: the existence of a first echo within a range of twice the distance of the second echo.

[0017] In some embodiments, determining the true echo from the second echo based on the characteristics of the second echo includes: in the case that there is no second echo that meets the criteria for judging a high-altitude target, determining the weight coefficient of the second echo based on the characteristics of the second echo; the criteria for judging a high-altitude target include: the existence of a first echo within twice the distance range of the second echo; and determining the second echo with the largest weight coefficient among the second echoes as the true echo.

[0018] In some embodiments, determining an effective echo intensity threshold based on the characteristics of each echo in the echo signal includes: determining an intensity statistical parameter of the echo signal based on the signal intensity of each echo in the echo signal; and determining an effective echo intensity threshold based on the intensity statistical parameter of the echo signal.

[0019] In some embodiments, the intensity statistics parameters include at least one of the following: mean, variance, standard deviation, and range.

[0020] In some embodiments, determining the intensity statistical parameters of the echo signal based on the signal strength of each echo in the echo signal includes: determining the intensity statistical parameters of the echo signal based on the signal strength of a preset number of echoes with the lowest signal strength in the echo signal.

[0021] In some embodiments, the high-reflection target echo range is determined as follows: the distance of the echo with a signal strength greater than the second high-reflection target strength threshold among all echo signals received by the lidar is determined as the high-reflection target distance; the second high-reflection target strength threshold is less than or equal to the first high-reflection target strength threshold; the high-reflection target distance range is determined based on a preset range length with the high-reflection target distance as the range center.

[0022] Secondly, embodiments of this application provide an echo extraction device for a lidar system, the device comprising:

[0023] The acquisition module is used to acquire the echo signal of the lidar, and the echo signal includes at least one echo.

[0024] The determination module is used to determine the effective echo intensity threshold of the echo signal based on the characteristics of each echo in the echo signal;

[0025] The determination module is also used to determine the true echo from at least one echo of the echo signal based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of the high-reflection target.

[0026] In some embodiments, the determining module is specifically used to determine the echoes in the echo signal whose signal strength is greater than the effective echo strength threshold as the first echo; and to determine the true echo from the first echo based on the characteristics of the first echo and the distance range of the high-reflection target echo.

[0027] In some embodiments, the determining module is specifically used to determine the closest first echo in the echo signal as the true echo when there is no first echo in the echo signal whose distance is within the range of the high-reflection target echo distance.

[0028] In some embodiments, the determining module is specifically used to determine the first echo as a real echo when there is a first echo in the echo signal whose distance is within the high-reflection target echo distance range and there is only one first echo in the echo signal, and the signal strength of the first echo is greater than the real object strength threshold.

[0029] In some embodiments, the real object intensity threshold is greater than the effective echo intensity threshold.

[0030] In some embodiments, the determining module is specifically used to determine the first echo that is closest to the target echo as the real echo when there are multiple first echoes in the echo signal and at least one of the multiple first echoes is within the distance range of the high-reflection target echo. If the signal strength of all the first echoes within the distance range of the high-reflection target echo is less than or equal to the first high-reflection target strength threshold, then the first echo that is closest to the target echo is taken as the real echo.

[0031] In some embodiments, the determining module is specifically used to determine the first echo among the multiple first echoes, where the distance of at least one of the multiple first echoes is within the range of the high-reflection target echo distance and the signal strength is greater than a first high-reflection target strength threshold, as the second echo when multiple first echoes exist in the echo signal and at least one of the multiple first echoes is within the range of the high-reflection target echo distance. Based on the characteristics of the second echo, the true echo is determined from the second echo.

[0032] In some embodiments, the determining module is specifically used to determine the second echo with the highest signal strength among the second echoes that meet the high-reflection target judgment conditions as the true echo. The high-reflection target judgment conditions include: the existence of a first echo within a range of twice the distance of the second echo.

[0033] In some embodiments, the determining module is specifically used to determine the weight coefficient of the second echo based on the characteristics of the second echo when there is no second echo that satisfies the high-reflection target judgment condition; the high-reflection target judgment condition includes: the existence of a first echo within twice the distance range of the second echo; and the second echo with the largest weight coefficient among the second echoes is determined as the true echo.

[0034] In some embodiments, the determining module is specifically used to determine the intensity statistical parameters of the echo signal based on the signal intensity of each echo in the echo signal; and to determine the effective echo intensity threshold based on the intensity statistical parameters of the echo signal.

[0035] In some embodiments, the intensity statistics parameters include at least one of the following: mean, variance, standard deviation, and range.

[0036] In some embodiments, the determining module is specifically used to determine the intensity statistical parameters of the echo signal based on the signal strength of a preset number of echoes with the lowest signal strength in the echo signal.

[0037] In some embodiments, the high-reflection target echo range is determined as follows: the distance of the echo with a signal strength greater than the second high-reflection target strength threshold among all echo signals received by the lidar is determined as the high-reflection target distance; the second high-reflection target strength threshold is less than or equal to the first high-reflection target strength threshold; the high-reflection target distance range is determined based on a preset range length with the high-reflection target distance as the range center.

[0038] Thirdly, an electronic device is provided, comprising: a processor and a memory for storing processor-executable instructions; wherein the processor is configured to execute instructions to implement the echo extraction method of the lidar described above.

[0039] Fourthly, an electronic device is provided, comprising: 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 laser radar echo extraction method described above.

[0040] Fifthly, a computer-readable storage medium is provided, on which computer program instructions are stored, which, when executed by a processor, implement the echo extraction method of the lidar of any of the above embodiments.

[0041] Sixthly, a lidar system is provided, which includes the electronic device described above, or the computer-readable storage medium described above.

[0042] In a seventh aspect, a vehicle is provided, comprising: the electronic device described above, or the computer-readable storage medium described above, or the lidar system described above.

[0043] Eighthly, a computer program product is provided, the computer program product including computer program instructions, which, when executed by a processor, implement the echo extraction method of the lidar of any of the above embodiments.

[0044] For a detailed description of aspects two through eight and their various implementations in this application, please refer to the detailed description in aspect one and its various implementations; and for a detailed description of the beneficial effects of aspects two through eight and their various implementations, please refer to the beneficial effect analysis in aspect one and its various implementations, which will not be repeated here. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments 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.

[0046] Figure 1 A schematic diagram of a highly reflective object provided in an embodiment of this application;

[0047] Figure 2 A schematic diagram illustrating the optical crosstalk principle of a lidar provided in this application embodiment;

[0048] Figure 3 A schematic diagram of crosstalk signal echo of a lidar provided in an embodiment of this application;

[0049] Figure 4 A flowchart illustrating a lidar echo extraction method provided in this application embodiment;

[0050] Figure 5 A flowchart illustrating another method for echo extraction from a lidar system provided in this application embodiment;

[0051] Figure 6 A flowchart illustrating another method for echo extraction from a lidar system provided in this application embodiment;

[0052] Figure 7 A flowchart illustrating another method for echo extraction from a lidar system provided in this application embodiment;

[0053] Figure 8 A flowchart illustrating another method for echo extraction from a lidar system provided in this application embodiment;

[0054] Figure 9 A flowchart illustrating another method for echo extraction from a lidar system provided in this application embodiment;

[0055] Figure 10 A flowchart for extracting the echo range of a high-reflectivity target is provided in an embodiment of this application;

[0056] Figure 11 A flowchart of an effective echo traversal provided in this application embodiment;

[0057] Figure 12 A schematic diagram of the structure of a lidar echo extraction device provided in an embodiment of this application;

[0058] Figure 13 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or relative positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplification, 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 this application. Unless otherwise specified, the above-mentioned orientational descriptions can be flexibly set in practical applications, provided that the relative positional relationships shown in the accompanying drawings are satisfied.

[0061] 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0062] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "communication" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0063] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0064] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0065] In the description of 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 alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more.

[0066] LiDAR is a crucial sensor in current vehicle autonomous driving systems. Compared to other sensors, LiDAR boasts advantages such as high reliability, long detection range, and strong detail resolution. The principle of LiDAR is dToF ranging, which essentially involves sending a laser pulse and using the internal signal processing components to determine the time required for the pulse to travel from emission to reception and return to calculate the distance. In other words, it measures the propagation time of the laser from the radar to the target and multiplies it by the known speed of light to obtain the final detection distance.

[0067] To increase the information content (point cloud density) of a single frame in a lidar system, most lidar systems control multiple laser transmitters and multiple laser receivers to simultaneously perform ranging. This increases the point cloud density while maintaining the lidar's point cloud refresh rate. However, this transmission and reception method can cause the lidar to detect false echoes due to high reflectivity when highly reflective objects are present in the field of view.

[0068] Figure 1 A schematic diagram of a highly reflective object provided in an embodiment of this application is shown below. Figure 1 As shown, when the lidar detects the high-reflection indicator road sign 104, it will be affected by the high-reflection expansion 101, outputting false object information 102, resulting in the inability to output true object information 103, which greatly reduces the accuracy of the lidar sensor.

[0069] The essence of the "high anti-expansion" phenomenon in lidar is optical crosstalk within the lidar detector.

[0070] Figure 2 A schematic diagram illustrating the optical crosstalk principle of a lidar provided in this application embodiment is shown below. Figure 2 As shown, the laser echo 201 from a highly reflective object, due to its high echo intensity, undergoes multipath reflection 204 when passing through the lens 202 or the protective cover 203 of the photosensitive device, or triggers its corresponding photosensitive unit 205, generating multipath reflection 206 within the detector, thereby triggering other photosensitive units and causing them to output incorrect detection information. When a highly reflective target is present within the lidar's field of view, the hot carriers generated by the lidar's photosensitive units overflow, emitting near-infrared crosstalk photons, which affect other photosensitive units, causing them to output incorrect detection information.

[0071] Optical crosstalk refers to the phenomenon in a multi-channel optical system where the optical signal from one channel affects the optical signals from other channels, leading to inaccurate images or data. Multipath reflection refers to the phenomenon where multiple signal paths arrive at the receiver due to reflection, refraction, or scattering during signal propagation.

[0072] In related technologies, most methods for eliminating crosstalk or high back-dilation in lidar systems achieve this through system or optical isolation, without addressing the crosstalk problem at the signal processing level. This approach can lead to misinterpreting real object echoes as crosstalk echoes when the echo intensity is high.

[0073] The echo intensity of the same highly reflective object varies at different distances. Especially at close range, the echo intensity of ordinary objects may be very high, while that of highly reflective targets is even higher, sometimes exceeding the maximum detectable echo intensity, resulting in high crosstalk echo intensity. Meanwhile, non-highly reflective targets, due to their close proximity to the radar, will also have high echo intensity, even saturation. If the detector cannot distinguish very strong echo intensities, especially when using single-photon counting technology, it is easy to confuse crosstalk echoes with real object echoes, leading to incorrect judgments. Related technologies rely excessively on echo intensity for crosstalk detection, making misjudgments likely.

[0074] Among them, single-photon counting technology is based on the particle nature of light, records the time difference between the arrival of a single photon and the corresponding excitation pulse in each event segment, and forms a statistical histogram of photon arrival time and number from multiple time segments.

[0075] Furthermore, current technologies rely solely on echo distance and intensity to identify crosstalk echoes, neglecting to consider the overall signal characteristics of a single echo. This can lead to some crosstalk echoes going undetected or real object echoes being mistakenly identified as crosstalk echoes. Moreover, retrieving all echo information from a single echo requires significant resources and computational complexity. Therefore, effectively filtering out false echoes with high anti-expansion properties and improving the accuracy of lidar sensors is a pressing technical challenge.

[0076] To address the aforementioned issues, this application provides a method for extracting echoes from a lidar system. By analyzing the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the range of high-reflectivity target echo distances, at least one echo in the echo signal is processed to filter out high-reflectivity dilated echoes and retain the true echoes, enabling the lidar to output more reliable and complete detection information.

[0077] Figure 3 This application provides a schematic diagram of crosstalk signal echo for a lidar system, as shown in the embodiment. Figure 3 As shown, the vertical axis represents the signal strength, and the horizontal axis represents the signal's time-of-flight / depth. When a photosensitive element detects a high-reflectivity target signal 301, its adjacent photosensitive elements will simultaneously detect crosstalk echoes 303 caused by multipath reflection or infrared crosstalk. The characteristics of the crosstalk echo are that there is a small time difference (Δt) between the arrival time of the crosstalk echo and the arrival time of the high-reflectivity target echo, and its intensity will attenuate as the distance between the high-reflectivity photosensitive element and the crosstalk photosensitive element increases.

[0078] Furthermore, due to their excessively high intensity, the echoes from highly reflective targets are easily reflected back out of the sensor via the same optical path, projected onto the highly reflective target again, and captured by the sensor once more. In the echo signal, a false secondary imaging echo 302, weaker than the original high-reflection target echo, can be detected approximately twice the time following the initial high-reflection target echo.

[0079] In addition, the low-reflection or ordinary target echo 304 is relatively stable and generally does not produce crosstalk echoes or false echoes in secondary imaging. There is a corresponding real echo 305 with low echo intensity.

[0080] It should be noted that the above description is for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and does not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new business scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0081] For ease of understanding, the echo extraction method of the lidar provided in this application will be described in detail below with reference to the accompanying drawings.

[0082] In some embodiments, the entity executing the lidar echo extraction method provided in this application may be the lidar itself, a detection device, a lidar control device, or a device or apparatus that can process the echo signal detected by the lidar, such as a lidar echo extraction device. This application does not impose any restrictions on this.

[0083] Figure 4 An echo extraction method for a lidar provided in this application embodiment, such as... Figure 4 As shown, the method includes the following steps S401-S403:

[0084] S401. Acquire the echo signal from the lidar.

[0085] The echo signal includes at least one echo.

[0086] For example, a lidar system can simultaneously emit one or more laser pulses via a laser emitter, and receive echo signals triggered by one or more sensor sources via a photodetector and a time-to-digital converter (TDC). Furthermore, echo extraction can be performed on the received echo signals based on a preset signal strength threshold, extracting echoes that reach the preset signal strength threshold as the lidar's echo signals.

[0087] In this setup, one light source corresponds to one echo signal. The photodetector can be a single-photon avalanche diode (SPAD), an avalanche photodiode (APD), or a silicon photomultiplier (SiPM). The time-to-digital converter can be a combination of a time-to-amplitude converter (TAC) and an analog-to-digital converter (ADC).

[0088] The preset signal strength threshold is a low strength threshold used to filter out echoes with low signal strength. The specific value can be set according to the configuration of the lidar and the environmental conditions. This application embodiment does not limit this.

[0089] S402. Based on the characteristics of each echo in the echo signal, determine the effective echo intensity threshold of the echo signal.

[0090] The characteristics of an echo include its signal strength and distance.

[0091] One possible approach is to determine the intensity statistics of the echo signal based on the signal strength of each echo in the echo signal, and then determine the effective echo intensity threshold based on the intensity statistics of the echo signal.

[0092] It should be noted that for multiple echo signals, an effective echo intensity threshold is determined for each echo signal based on the echo intensity of at least one echo within each signal. Therefore, one effective echo intensity threshold corresponds to one echo signal. The effective echo intensity threshold represents the signal strength threshold of the actual echo of that echo signal. The effective echo intensity threshold is greater than the aforementioned preset echo intensity threshold.

[0093] S403. Based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of the high-reflection target, determine the true echo from at least one echo in the echo signal.

[0094] Among them, the high-reflection target echo range is the statistical range of multiple high-reflection target echoes based on one or more echo signals from lidar.

[0095] It should be noted that an echo signal may have only one true echo, or there may be no true echo due to environmental factors.

[0096] In some embodiments, echoes with signal strength greater than the effective echo strength threshold can be identified as first echoes, thereby determining the true echoes of the echo signal from the first echoes. Therefore, as Figure 5 As shown, the above steps, based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of high-reflection targets, determine the true echo from at least one echo in the echo signal. Specifically, this can be achieved through the following steps S4031-S4032:

[0097] S4031. The echo with a signal strength greater than the effective echo strength threshold is identified as the first echo.

[0098] S4032. Based on the characteristics of the first echo and the range of the high-reflection target echo, determine the true echo from the first echo.

[0099] In some embodiments, the first echo can be matched with the range of high-reflection target echoes based on its echo intensity and distance. Thus, based on the matching result between the first echo and the range of high-reflection target echoes, the true echo signal can be determined from the first echo.

[0100] In some embodiments, the methods for determining the true echo from the first echo vary depending on the relationship between the distance of the first echo and the range of the high-reflection target echo.

[0101] As one implementation of S4032: when no first echo in the echo signal is within the range of the high-reflection target echo distance, the first echo in the echo signal that is closest is taken as the real echo.

[0102] It should be understood that if no single echo in the echo signal falls within the range of the echo distance of a high-reflection target, it indicates that all echoes in the signal are low-reflection or ordinary echoes, unaffected by the high-reflection object. Therefore, the closest echo in the signal can be directly taken as the true echo of the signal.

[0103] As another implementation of S4032: if there is a first echo in the echo signal whose distance is within the echo distance range of the high-reflection target, and there is only one first echo in the echo signal, if the signal strength of the first echo is greater than the real object strength threshold, then the first echo is determined to be the real echo.

[0104] Among them, the real object intensity threshold is greater than the effective echo intensity threshold.

[0105] It should be understood that if there is a first echo in the echo signal whose distance is within the range of the high-reflection target echo, and there is only one first echo in the echo signal, it indicates that the first echo is likely the true echo of the echo signal. Therefore, the first echo can be directly compared with the true object intensity threshold. If the signal intensity of the first echo is greater than the true object intensity threshold, it indicates that the first echo is the true echo of the echo signal.

[0106] If the signal strength of the first echo is less than or equal to the threshold of the real object strength, it indicates that the first echo is not a real echo, and the echo signal may not have a real echo.

[0107] The real object intensity threshold is determined based on the configuration of the lidar and the object characteristics in the environment where the lidar is located.

[0108] As another implementation of S4032: if there are multiple first echoes in the echo signal, and at least one of the multiple first echoes is within the distance range of the high-reflection target echo, if the signal strength of the first echoes within the distance range of the high-reflection target echo is less than or equal to the first high-reflection target strength threshold, then the first echo with the closest distance in the echo signal is taken as the real echo.

[0109] If multiple first echoes exist in the echo signal, and at least one of these first echoes is within the range of the high-reflectivity target echo, it indicates the presence of a false high-reflectivity expansion echo among the multiple first echoes. False high-reflectivity expansion echoes can be filtered out from the multiple first echoes by considering the high-reflectivity target echo range. Furthermore, first echoes within the high-reflectivity target echo range can be selected based on a first high-reflectivity target intensity threshold. If all first echoes within the high-reflectivity target echo range are less than or equal to the first high-reflectivity target intensity threshold, it indicates the presence of low-reflectivity or ordinary echoes among the multiple first echoes, unaffected by the high-reflectivity object. Therefore, the first echo closest to the target in the echo signal can be directly taken as the true echo of the signal.

[0110] As another implementation of S4032: when the distance range of the first echo matches that of the high-reflection target echo, and there are multiple first echoes in the echo signal, the true echo can be determined based on the signal strength of the multiple first echoes. Therefore, as... Figure 6 As shown, the above steps determine the true echo from the first echo based on the characteristics of the first echo in the echo signal and the distance range of the high-reflection target echo. Specifically, this can be achieved through the following steps S4032a-S4032b:

[0111] S4032a. If there are multiple first echoes in the echo signal, and at least one of the multiple first echoes has a distance within the range of the high-reflection target echo distance, the first echo among the multiple first echoes whose distance is within the range of the high-reflection target echo distance and whose signal strength is greater than the first high-reflection target strength threshold shall be identified as the second echo.

[0112] Among them, the intensity threshold of the first high-reflectivity target is greater than the intensity threshold of the real object.

[0113] If multiple first echoes exist in the echo signal, and at least one of these first echoes is within the range of the high-reflection target echo, it indicates the presence of a high-reflection expansion spurious echo among the multiple first echoes. Therefore, after filtering out the high-reflection expansion spurious echoes from the multiple first echoes by using the high-reflection target echo range, the signal strength of the first echoes within the high-reflection target echo range can be compared with a first high-reflection target strength threshold. Thus, the first echo with a signal strength greater than the first high-reflection target strength threshold among the first echoes within the high-reflection target echo range is identified as a second echo. The first echo with a signal strength less than or equal to the first high-reflection target strength threshold among the multiple first echoes is considered an invalid echo.

[0114] It should be understood that the first high-reflectivity target intensity threshold is set based on the configuration of the lidar and the environmental conditions detected by the lidar, and this application embodiment does not limit this.

[0115] S4032b: Based on the characteristics of the second echo, the true echo is determined from the second echo.

[0116] In some embodiments, the signal strength and echo distance of the second echo can be used to determine whether the second echo meets the criteria for identifying a high-reflection target. Based on the determination result of the second echo, the true echo can then be identified from the second echo.

[0117] In some embodiments, the above steps determine the true echo from the second echo based on its characteristics, which can be achieved through the following steps:

[0118] The second echo with the highest signal strength among the second echoes that meet the criteria for high-reflection target identification is determined as the true echo.

[0119] Among them, the criteria for judging high-altitude targets include: the presence of a first echo within a range of twice the distance of the second echo.

[0120] For example, the second echoes can be sorted from highest to lowest signal strength. Then, for each second echo in the echo signal, it can be determined whether a first echo exists within a range twice the distance of the second echo. If any first echo exists within a range twice the distance of the second echo, based on the characteristics of high-reflection expansion virtual echoes, this second echo is considered a true echo. Therefore, the second echo with the highest signal strength among those satisfying the high-reflection target determination criteria can be directly identified as the true echo. Other echoes in the echo signal are considered invalid echoes.

[0121] Among them, the characteristic of high-inflection expansion virtual echo is that the echo distance of high-inflection expansion virtual echo is generally twice that of real echo.

[0122] In some embodiments, such as Figure 7 As shown, the above steps, based on the characteristics of the second echo, determine the true echo from the second echo, which can be specifically achieved through the following steps S701-S702:

[0123] S701. In the absence of a second echo that meets the criteria for judging a high-altitude target, determine the weighting coefficient of the second echo based on its characteristics.

[0124] Among them, the criteria for judging high-altitude targets include: the presence of a first echo within a range of twice the distance of the second echo.

[0125] In some embodiments, if there is no second echo that meets the criteria for judging a high-reflection target, the weighting coefficient of each second signal in the echo signal can be determined based on the characteristics of the second echo, such as echo distance, signal strength, and pulse width.

[0126] S702. The second echo with the largest weighting coefficient is determined as the true echo.

[0127] In some embodiments, if there is only a single second echo with a weighted coefficient, the second echo with the weighted coefficient can be directly identified as the true echo. If there are multiple second echoes with weighted coefficients, the second echo with the largest weighted coefficient is identified as the true echo.

[0128] For example, the process of extracting the real echo in the above steps is described with an example.

[0129] The first echoes with a signal strength greater than the effective echo strength threshold include: a, b, c, d, and e. Among these, the distances of b and c are within the range of high-reflectivity target echo distances. The signal strengths of b and c are compared with the first high-reflectivity target strength threshold. If the signal strengths of b and c are less than or equal to the first high-reflectivity target strength threshold, the first echo with the shortest distance from a, b, c, d, and e is directly determined as the true echo.

[0130] If the signal strengths of b and c are greater than the first high-reflectivity target strength threshold, b and c are identified as the second echoes, and it is determined whether there are echoes at twice the distance of b and c among a, d, and e. If there are no echoes at twice the distance of either b or c among a, d, and e, weighting coefficients for b and c are determined based on their echo characteristics, and the true echoes are determined according to these weighting coefficients.

[0131] If the echo is at a distance twice that of b, and there is no echo at a distance twice that of c among d and e, then b is determined to be the true echo of the echo signal. If the echo is at a distance twice that of b, and d is twice that of c, then the echo with the highest echo intensity among b and c is determined to be the true echo of the echo signal. In some embodiments, such as... Figure 8 As shown, the above steps determine the effective echo intensity threshold based on the characteristics of each echo in the echo signal, which can be specifically achieved through the following steps S4021-S4022:

[0132] S4021. Based on the signal intensity of each echo in the echo signal, determine the intensity statistical parameters of the echo signal.

[0133] The intensity statistical parameters include at least one of the following: mean, variance, standard deviation, and range.

[0134] One possible implementation is to select a predetermined number of echoes with the lowest signal strength from at least one echo of the echo signal. Statistical parameters can then be determined based on the statistical characteristics of the signal strengths of this predetermined number of echoes.

[0135] S4022. Determine the effective echo intensity threshold based on the intensity statistical parameters of the echo signal.

[0136] For example, the mean μ and variance σ of the signal intensity of a preset number of echoes in a Gaussian distribution, or the eigenvalue λ of the signal intensity of at least one echo in a Poisson distribution, or the eigenvalue μ±3σ of the outlier point of the signal intensity of at least one echo in a Gaussian distribution, can be determined as the effective echo intensity threshold.

[0137] It should be understood that the echo with the lowest signal strength in the echo signal may be an echo of optical noise or a secondary reflection signal from a highly reflective object. Therefore, determining the effective echo strength threshold based on the mean and variance of the distances of a preset number of echoes with the lowest signal strength can effectively filter out optical noise (e.g., sunlight noise, stray light noise, dark counting noise, etc.) while optimizing computational complexity, significantly reducing the algorithm complexity, resource consumption, and running time of the backend endpoint cloud processing algorithm.

[0138] It should be noted that the receiver of a lidar should be able to detect and output as many echoes as possible for a single photosensitive element, in order to more accurately calculate the mean and variance of low-intensity echoes. For example, the receiver should be able to detect and output no fewer than four echoes for a single photosensitive element.

[0139] In some embodiments, the echo range of a high-reflection target is determined according to the following steps S801-S802:

[0140] S801. The distance of the echo with a signal strength greater than the second high-reflectivity target strength threshold among all echo signals received by the lidar is determined as the high-reflectivity target distance.

[0141] Among them, the intensity threshold of the second high-reflectivity target is slightly less than or equal to the intensity threshold of the first high-reflectivity target, and the intensity threshold of the second high-reflectivity target is greater than the intensity threshold of the real object.

[0142] In some embodiments, the distance of all echoes with signal strength greater than the second high-reflection target strength threshold can be recorded.

[0143] In some embodiments, a distance redundancy threshold can be set. If the distance of the echo is not within the range of distance redundancy of any stored distance, it is recorded. For example, if the recorded echo distance includes 3m, echo distances within 3±0.5m will not be recorded. The distance redundancy range can be set according to requirements, such as ±0.2m, ±0.5m, etc., and this embodiment does not limit this.

[0144] S802. Determine the range of high-reflection target distance based on the preset range length, with the high-reflection target distance as the range center.

[0145] The preset range length can be set according to requirements, and can be ±0.2m, ±0.5m, etc. This application embodiment does not limit this.

[0146] It should be understood that the lidar echo extraction method of this application can effectively filter out lidar crosstalk signals without optimizing optics, systems, circuits, or point cloud algorithms, enabling the sensor to output true and effective detection information. Furthermore, the lidar echo extraction method of this application is universally applicable to most dToF lidar software signal processing algorithms and a large number of lidar systems based on dToF ranging as the primary solution. It is also universally applicable to different lidar systems / optical schemes, such as vertical cavity surface emitting lasers (VCSELs), edge-emitting lasers (EELs), SPADs, APDs, SiPMs, etc.

[0147] Furthermore, the lidar echo extraction method of this application does not rely on additional hardware control circuits or optical crosstalk suppression modules, offering advantages such as low cost, low complexity, and high versatility. Compared to point cloud image optimization schemes, the lidar echo extraction method of this application, while effective in removing a certain number of high-inflection dilatation points (since point cloud image processing algorithms are generally downstream of signal processing algorithms), cannot obtain complete information from the lidar echo signal and therefore cannot replenish the information of the real / occluding objects behind the dilatated point cloud after point deletion. This application, however, can process the original lidar echo signal, filtering out high-inflection dilatation information while retaining the information of the real / occluding objects behind it, thus outputting more reliable and complete detection information.

[0148] The lidar echo extraction method of this application utilizes the signal characteristics received by a single sensor light source to filter effective echoes, and only compares and judges effective echoes. This increases the amount of usable information in the signal while reducing the algorithm complexity. At the same time, it makes the algorithm applicable to more signal echo states, and the algorithm is highly adaptable and robust.

[0149] When a possible crosstalk echo is detected, the intensity threshold is adjusted based on the overall characteristics of the current signal and the number of effective echoes, and weights are applied to the judgment. This can greatly avoid the possibility of misjudgment or missed judgment, and at the same time make the algorithm processing results more accurate, thereby improving the authenticity and effectiveness of sensor information.

[0150] Figure 9 A flowchart of another lidar echo extraction method provided in the embodiments of this application is shown below. Figure 9 As shown, the method includes the following steps:

[0151] S901: Receive all echo signals triggered simultaneously.

[0152] S902. Extract echoes from all echo signals according to a preset signal strength threshold.

[0153] S903, Crosstalk Distance Traversal.

[0154] S904, Effective Echo Traversal.

[0155] S905 outputs true echo.

[0156] Figure 10 A flowchart for extracting the echo range of a high-reflection target is provided as an embodiment of this application, such as... Figure 10 As shown, the method includes the following steps:

[0157] S1001, Traverse all echo signals after extraction.

[0158] S1002. Based on the statistical characteristics of the preset number of echoes with the lowest signal strength, determine the effective echo strength threshold and set the second high-reflection target strength threshold.

[0159] S1003. Determine whether the intensity of the extracted echo is higher than the effective echo intensity threshold.

[0160] S1004. If the intensity of the extracted echo is not higher than the effective echo intensity threshold, the echo is marked as an invalid echo.

[0161] S1005. If the intensity of the extracted echo is higher than the effective echo intensity threshold, the echo is marked as the first echo.

[0162] S1006 determines whether the intensity of the first echo is higher than the second high-reflection target intensity threshold.

[0163] S1007. If the intensity of the first echo is higher than the second high-reflection target intensity threshold, record the echo distance of the echo.

[0164] S1008. If the intensity of the first echo is not higher than the intensity threshold of the second high-reflection target, determine whether the traversal has ended. If the traversal has ended, end the process; otherwise, return to step S1001.

[0165] Figure 11 A flowchart of an effective echo traversal provided in this application embodiment is included, the method comprising the following steps:

[0166] S1101, Repeat the process of extracting all echo signals.

[0167] S1102. Determine whether the signal has a first echo within the high-reflection target echo range.

[0168] S1103. If there is no first echo within the high-reflection target echo range of the signal, mark the nearest first echo as the real echo and the others as invalid echoes.

[0169] S1104. If the signal has a first echo within the range of high-reflection target echo distance, determine the number of first echoes in the signal.

[0170] S1105. If the signal has multiple first echoes, traverse the multiple first echoes.

[0171] S1106. Determine whether the distance of the first echo is within the range of the high-reflection target echo distance.

[0172] S1107. If the distance of the first echo is within the range of the high-reflection target echo distance, determine whether the intensity of the first echo is higher than the first high-reflection target intensity threshold.

[0173] If the distance of the first echo is within the range of the high-reflection target echo distance, determine whether the traversal of multiple first echoes has ended.

[0174] S1108. If the intensity of the first echo is not higher than the first high-reflection target intensity threshold, the echo is marked as an invalid echo.

[0175] S1109. If the intensity of the first echo is higher than the first high-reflection target intensity threshold, determine that the first echo is the second echo, and determine whether there is an echo in the first echo that is twice the distance of the second echo.

[0176] S1110. If there is no echo in the first echo that is twice the distance of the second echo, assign a weighting coefficient to the second echo.

[0177] S1111 If there is an echo in the first echo that is twice the distance of the second echo, mark the second echo with the highest signal strength in the second echo that meets the high-reflection target judgment condition as the real echo, and the other echoes as invalid echoes.

[0178] For example, if the second echo of the signal has three echoes, A, B, and C, and the echo distance of B is twice the echo distance of A, then A is directly determined to be the true echo of the signal.

[0179] If there are no echoes with double the echo distance in A, B, and C, then weighting coefficients are configured based on the echo characteristics of A, B, and C.

[0180] S1112, Determine if the traversal has ended.

[0181] S1113. When the traversal is complete, determine the number of second echoes with weighting coefficients configured on the signal.

[0182] If the traversal is not yet complete, return to step S1105.

[0183] S1114. If the number of echoes recording the weighting coefficient on the signal is a single echo, mark the second echo as a true echo and the other echoes as invalid echoes.

[0184] S1115. When there are multiple echoes with weighted coefficients recorded on the signal, the true echo is calculated, judged, and determined based on the weights.

[0185] S1116. When the number of echoes recording the weighting coefficients on the signal is zero, mark the nearest echo as the real echo and the others as invalid echoes.

[0186] S1117. In the case that the signal has a single first echo, determine whether the intensity of the echo is higher than the intensity threshold of the real object.

[0187] S1118. If the intensity of the echo is not higher than the intensity threshold of the real object, mark the echo as an invalid echo.

[0188] S1119. If the intensity of the echo is higher than the intensity threshold of the real object, mark the echo as a real echo and proceed to step S1118.

[0189] S1120. Determine if the traversal has ended. If the traversal has ended, end the process; otherwise, return to step S1101.

[0190] The foregoing mainly describes the solutions of the embodiments of this application from a methodological perspective. It is understood that, in order to achieve the above-mentioned functions, the lidar echo extraction device includes at least one of the hardware structures and software modules corresponding to each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware 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 the embodiments of this application.

[0191] This application embodiment can divide the echo extraction device of lidar into functional modules according to the above method embodiment. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one functional module. The integrated module can be implemented in hardware or software. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. The following description uses the example of dividing each functional module according to each function.

[0192] Figure 12 This is a schematic diagram of the structure of a lidar echo extraction device provided in an embodiment of this application. The lidar echo extraction device can perform the lidar echo extraction method provided in the above-described method embodiment. For example... Figure 12 As shown, the lidar echo extraction device 1200 includes an acquisition module 1201 and a determination module 1202.

[0193] The acquisition module 1201 is used to acquire the echo signal of the lidar, the echo signal including at least one echo;

[0194] The determination module 1202 is used to determine the effective echo intensity threshold of the echo signal based on the characteristics of each echo in the echo signal;

[0195] The determining module 1202 is also used to determine the true echo from at least one echo of the echo signal based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of the high-reflection target.

[0196] In some embodiments, the determining module 1202 is specifically used to determine the echoes in the echo signal whose signal strength is greater than the effective echo strength threshold as the first echo; and to determine the true echo from the first echo based on the characteristics of the first echo and the distance range of the high-reflection target echo.

[0197] In some embodiments, the determining module 1202 is specifically used to determine the closest first echo in the echo signal as the real echo when there is no first echo in the echo signal whose distance is within the range of the high-reflection target echo distance.

[0198] In some embodiments, the determining module 1202 is specifically used to determine the first echo as a real echo when there is a first echo in the echo signal whose distance is within the echo distance range of the high-reflection target, and there is only one first echo in the echo signal, and the signal strength of the first echo is greater than the real object strength threshold.

[0199] In some embodiments, the real object intensity threshold is greater than the effective echo intensity threshold.

[0200] In some embodiments, the determining module 1202 is specifically used to determine the first echo that is closest to the target echo as the real echo when there are multiple first echoes in the echo signal and at least one of the multiple first echoes is within the distance range of the high-reflection target echo. If the signal strength of all the first echoes within the distance range of the high-reflection target echo is less than or equal to the first high-reflection target strength threshold, then the first echo that is closest to the target echo is taken as the real echo.

[0201] In some embodiments, the determining module 1202 is specifically used to determine the first echo among the multiple first echoes, where the distance of at least one of the multiple first echoes is within the range of the high-reflection target echo distance and the signal strength is greater than the first high-reflection target strength threshold, as the second echo when multiple first echoes exist in the echo signal and at least one of the multiple first echoes is within the range of the high-reflection target echo distance. Based on the characteristics of the second echo, the true echo is determined from the second echo.

[0202] In some embodiments, the determining module 1202 is specifically used to determine the second echo with the highest signal strength among the second echoes that meet the high-reflection target judgment conditions as the true echo. The high-reflection target judgment conditions include: the existence of a first echo within a range of twice the distance of the second echo.

[0203] In some embodiments, the determining module 1202 is specifically used to determine the weight coefficient of the second echo based on the characteristics of the second echo when there is no second echo that meets the criteria for judging a high-altitude target; the criteria for judging a high-altitude target include: the existence of a first echo within twice the distance range of the second echo; and the second echo with the largest weight coefficient among the second echoes is determined as the true echo.

[0204] In some embodiments, the determining module 1202 is specifically used to determine the intensity statistical parameters of the echo signal based on the signal intensity of each echo in the echo signal; and to determine the effective echo intensity threshold based on the intensity statistical parameters of the echo signal.

[0205] In some embodiments, the intensity statistics parameters include at least one of the following: mean, variance, standard deviation, and range.

[0206] In some embodiments, the determining module 1202 is specifically used to determine the intensity statistical parameters of the echo signal based on the signal strength of a preset number of echoes with the lowest signal strength in the echo signal.

[0207] In some embodiments, the high-reflection target echo range is determined as follows: the distance of the echo with a signal strength greater than the second high-reflection target strength threshold among all echo signals received by the lidar is determined as the high-reflection target distance; the second high-reflection target strength threshold is less than or equal to the first high-reflection target strength threshold; the high-reflection target distance range is determined based on a preset range length with the high-reflection target distance as the range center.

[0208] When implementing the functions of the integrated modules described above in hardware, this application provides a possible structure for the electronic device involved in the above embodiments. For example... Figure 13 As shown, the electronic device 1300 includes: a processor 1302 and a bus 1304. Optionally, the electronic device 1300 may also include a memory 1301; optionally, the electronic device 1300 may also include a communication interface 1303.

[0209] Processor 1302 may implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with embodiments of this application. Processor 1302 may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with embodiments of this application. Processor 1302 may also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0210] The communication interface 1303 is used to connect to other devices via a communication network. This communication network can be Ethernet, wireless access network, wireless local area network (WLAN), etc.

[0211] The memory 1301 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0212] As one possible implementation, the memory 1301 can exist independently of the processor 1302. The memory 1301 can be connected to the processor 1302 via a bus 1304 and is used to store instructions or program code. When the processor 1302 calls and executes the instructions or program code stored in the memory 1301, it can implement the laser radar echo extraction method provided in this application embodiment.

[0213] In another possible implementation, the memory 1301 can also be integrated with the processor 1302.

[0214] The 1304 bus can be an extended industry standard architecture (EISA) bus, etc. The 1304 bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 13 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0215] Some embodiments of this application provide a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) storing computer program instructions that, when executed on a computer, cause the computer to perform a lidar echo extraction method as described in any of the above embodiments.

[0216] For example, the aforementioned computer-readable storage media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact disks (CDs), digital versatile disks (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). The various computer-readable storage media described in this application may represent one or more devices and / or other machine-readable storage media for storing information. The term "machine-readable storage medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0217] This application provides a computer program product containing instructions that, when run on a computer, cause the computer to execute the echo extraction method of the lidar in any of the above embodiments.

[0218] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0219] The above are merely specific embodiments 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 for echo extraction from a lidar system, characterized in that, The method includes: Acquire the echo signal of the lidar, wherein the echo signal includes at least one echo; Based on the characteristics of each echo in the echo signal, the effective echo intensity threshold of the echo signal is determined; Based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the high-reflection target echo distance range, the true echo is determined from at least one echo in the echo signal.

2. The method according to claim 1, characterized in that, The step of determining the true echo from at least one echo of the echo signal based on the characteristics of each echo in the echo signal, the effective echo intensity threshold, and the echo distance range of the high-reflection target includes: The echoes whose signal strength is greater than the effective echo strength threshold are identified as the first echoes. Based on the characteristics of the first echo and the distance range of the high-reflection target echo, the true echo is determined from the first echo.

3. The method according to claim 2, characterized in that, The step of determining the true echo from the first echo based on its characteristics and the distance range of the high-reflection target echo includes: If no first echo in the echo signal is within the distance range of the high-reflection target echo, the first echo that is closest in the echo signal is taken as the true echo.

4. The method according to claim 2, characterized in that, The step of determining the true echo from the first echo based on its characteristics and the distance range of the high-reflection target echo includes: If there is a first echo in the echo signal at a distance within the echo distance range of the high-reflection target, and there is only one first echo in the echo signal, then if the signal strength of the first echo is greater than the real object strength threshold, the first echo is determined to be the real echo.

5. The method according to claim 4, characterized in that, The real object intensity threshold is greater than the effective echo intensity threshold.

6. The method according to claim 2, characterized in that, The step of determining the true echo from the first echo based on its characteristics and the distance range of the high-reflection target echo includes: If there are multiple first echoes in the echo signal, and at least one of the multiple first echoes is within the distance range of the high-reflection target echo, and if the signal strength of all first echoes within the distance range of the high-reflection target echo is less than or equal to the first high-reflection target strength threshold, then the first echo closest to the first echo in the echo signal is taken as the true echo.

7. The method according to claim 2, characterized in that, The step of determining the true echo from the first echo based on its characteristics and the distance range of the high-reflection target echo includes: If there are multiple first echoes in the echo signal, and at least one of the multiple first echoes has a distance within the echo distance range of the high-reflection target, then the first echo among the multiple first echoes whose distance is within the echo distance range of the high-reflection target and whose signal strength is greater than the first high-reflection target strength threshold is determined as the second echo. Based on the characteristics of the second echo, the true echo is determined from the second echo.

8. The method according to claim 7, characterized in that, The step of determining the true echo from the second echo based on its characteristics includes: The second echo with the highest signal strength among the second echoes that meet the criteria for judging high-reflection targets is determined as the true echo. The criteria for judging high-reflection targets include: the existence of a first echo within a range of twice the distance of the second echo.

9. The method according to claim 7, characterized in that, The step of determining the true echo from the second echo based on its characteristics includes: In the absence of a second echo that meets the criteria for identifying a high-altitude target, the weighting coefficient of the second echo is determined based on its characteristics; the criteria for identifying a high-altitude target include: the existence of a first echo within a range twice the distance of the second echo; The second echo with the largest weighting coefficient is determined as the true echo.

10. The method according to any one of claims 1 to 9, characterized in that, The determination of the effective echo intensity threshold based on the characteristics of each echo in the echo signal includes: Based on the signal intensity of each echo in the echo signal, the intensity statistical parameters of the echo signal are determined; The effective echo intensity threshold is determined based on the intensity statistical parameters of the echo signal.

11. The method according to claim 10, characterized in that, The intensity statistical parameters include at least one of the following: mean, variance, standard deviation, and range.

12. The method according to claim 10, characterized in that, The determination of the intensity statistical parameters of the echo signal based on the signal intensity of each echo in the echo signal includes: The intensity statistical parameters of the echo signal are determined based on the signal strength of the preset number of echoes with the lowest signal strength in the echo signal.

13. The method according to any one of claims 1 to 12, characterized in that, The range of echo distance from the high-reflectivity target is determined according to the following method: The distance of the echo signal with a signal strength greater than the second high-reflectivity target strength threshold among all echo signals received by the lidar is determined as the high-reflectivity target distance; the second high-reflectivity target strength threshold is less than or equal to the first high-reflectivity target strength threshold. The range of the high-reflection target distance is determined with the high-reflection target distance as the center of the range and based on a preset range length.

14. An electronic device, characterized in that, include: A processor and a memory for storing processor-executable instructions; The processor is configured to execute the instructions to implement the method as described in any one of claims 1 to 13.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 13.

16. A lidar system, characterized in that, The lidar system includes the electronic device as described in claim 14, or the computer-readable storage medium as described in claim 15.

17. A vehicle, characterized in that, include: The electronic device of claim 14, or the computer-readable storage medium of claim 15, or the lidar system of claim 16.

18. A computer program product, characterized in that, The computer program product includes computer instructions that, when executed on an electronic device, cause the electronic device to perform the method as described in any one of claims 1 to 13.

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