Echo data processing method and device, terminal equipment and storage medium

Abstract

The invention is suitable for the technical field of radar, and provides an echo data processing method and device, terminal equipment and a storage medium, and the method comprises the steps: obtaining echo data corresponding to multiple times of scanning, and determining echo features according to the echo data; determining target echo data according to the echo features of the current scanning and the echo features of the last scanning; the target echo data is echo data after high-reflection expansion echoes are filtered out; according to the method and the device, target echo data are fused, and target identification is carried out according to the fused target echo data, so that in the data fusion process, high-reflection expansion echoes corresponding to high-reflectivity objects are filtered and then data fusion is carried out, and point clouds corresponding to point cloud expansion are effectively filtered; therefore, the influence of point cloud expansion on the object recognition capability of the laser radar is reduced, and the object recognition accuracy of the laser radar is improved.

Description

Technical Field

[0001] This application belongs to the field of radar technology, and in particular relates to an echo data processing method, apparatus, terminal equipment and storage medium. Background Technology

[0002] LiDAR (Light Detection and Ranging) is a radar system that uses laser beams to detect the position, velocity, and other information of targets. Besides detecting the distance to objects, it can also detect the reflectivity of objects used for target identification. The specific working principle of LiDAR is to emit a detection signal towards the target. After reaching the target, the signal is reflected by the target object, forming echo data. LiDAR receives the reflected signal (echo data) and then determines relevant information about the target based on the echo data, such as the target's distance, position, altitude, velocity, attitude, shape, and reflectivity, thereby achieving target detection, target tracking, and target identification.

[0003] When a lidar detects a highly reflective object, point cloud expansion occurs. This is because highly reflective objects reflect a large amount of energy, more than 100 times that of objects with normal reflectivity. This causes the point cloud data to diffuse or expand during generation, which in turn affects the lidar's ability to identify objects. Summary of the Invention

[0004] This application provides an echo data processing method, apparatus, terminal device, and storage medium that can effectively filter point clouds corresponding to point cloud dilation, thereby reducing the impact of point cloud dilation on the object recognition capability of lidar and improving the object recognition accuracy of lidar.

[0005] In a first aspect, embodiments of this application provide an echo data processing method, including:

[0006] Acquire echo data corresponding to multiple scans, and determine echo characteristics based on the echo data;

[0007] The target echo data is determined based on the echo characteristics of the current scan and the echo characteristics of the previous scan; the target echo data is the echo data after filtering out echoes with high anti-expansion.

[0008] The aforementioned target echo data are fused to perform target identification based on the fused target echo data.

[0009] In one implementation of the first aspect, the echo features include the echo area, and determining the target echo data based on the echo features of the current scan and the echo features of the previous scan includes:

[0010] If there is a high-inflection-expansion echo in the current scan or the echo in the previous scan, then the echo data corresponding to the scan with the smaller echo area is determined as the target echo data.

[0011] If there is no echo with high anti-expansion in the echo of the current scan or the echo of the previous scan, then the echo data corresponding to the scan with the larger echo area is determined as the target echo data.

[0012] If the absolute difference between the echo area of ​​the current scan and the echo area of ​​the previous scan is less than a preset area difference threshold, or if the absolute difference between the distance value corresponding to the echo of the current scan and the distance corresponding to the echo of the previous scan is less than a distance difference threshold, then the average of the echo data of the current scan and the echo data of the previous scan will be used as the target echo data.

[0013] In one implementation of the first aspect, the aforementioned echo characteristics include transmit power, and determining the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan includes:

[0014] If there is a high-inflection-expansion echo in the current scan or the echo of the previous scan, then the echo data corresponding to the scan with low transmission power will be determined as the target echo data.

[0015] If there is no high-inflection-expansion echo in the current scan or the previous scan, then the echo data corresponding to the scan with high transmission power will be determined as the target echo data.

[0016] If the absolute difference between the transmit power of the current scan and the transmit power of the previous scan is less than a preset power difference threshold, or if the absolute difference between the distance value corresponding to the echo of the current scan and the distance value corresponding to the echo of the previous scan is less than a distance difference threshold, then the average of the echo data of the current scan and the echo data of the previous scan will be used as the target echo data.

[0017] In one implementation of the first aspect, before determining the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan, the method further includes:

[0018] The echo peak value and echo width of each echo are determined based on the detection results;

[0019] If the echo peak value is greater than or equal to the peak value threshold and the echo width is greater than or equal to the width threshold, then the above echo is determined to be the echo corresponding to a high reflectivity object.

[0020] The echo data corresponding to objects with high reflectivity are filtered out from the above echo data to obtain the echo data after detection and filtering.

[0021] In one implementation of the first aspect, after determining the echo peak value and echo width of each echo based on the detection results, the method further includes:

[0022] Determine the peak threshold and width threshold for the time interval of the echo, where different peak thresholds and width thresholds are set for different time intervals;

[0023] If the peak value of the echo is greater than or equal to the peak threshold corresponding to the time interval in which the echo is located, and the width of the echo is greater than or equal to the width threshold corresponding to the time interval in which the echo is located, then the echo is determined to be an echo corresponding to a high reflectivity object.

[0024] In one implementation of the first aspect, the echo data is the echo data received by the lidar after it performs transmit and receive control based on a preset scanning method. The preset scanning method is a scanning method in which the lidar's transmitting laser emits detection signals block by block, and the echo signals are received by a receiving unit group corresponding to the transmitting block. The receiving unit group includes at least two receiving units.

[0025] In one implementation of the first aspect, before determining the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan, the method further includes:

[0026] High-inflection filtering is applied to the echo data based on the effective data range.

[0027] In one implementation of the first aspect, the high-inflection filtering of the echo data based on the effective data range includes:

[0028] Based on the distance value corresponding to the echo and the position of the LiDAR transmitter block, the range of received pixels in the effective reception interval is determined from the effective reception interval table.

[0029] If the receiving range of the above echo exceeds the receiving pixel range of the above effective receiving interval, then the corresponding echo data within the effective receiving interval will be output.

[0030] If the receiving range of the above echo is within the receiving pixel range of the above effective receiving interval, then all echo data will be output.

[0031] Secondly, embodiments of this application provide an echo data processing apparatus, comprising:

[0032] The acquisition unit is used to acquire echo data corresponding to multiple scans and determine echo characteristics based on the echo data.

[0033] The determining unit is used to determine the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan; the target echo data is the echo data after filtering out echoes with high back expansion.

[0034] The fusion unit is used to fuse the aforementioned target echo data in order to perform target identification based on the fused target echo data.

[0035] Thirdly, embodiments of this application provide a terminal device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method described in the first aspect or any optional method of the first aspect.

[0036] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect or any optional manner of the first aspect.

[0037] Fifthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the method described in the first aspect or any optional method of the first aspect.

[0038] The beneficial effects of the embodiments in this application compared with the prior art are:

[0039] This application provides an echo data processing method, apparatus, terminal device, and computer-readable storage medium. For echo data obtained from multiple scans, it can filter out the high-reflectivity dilatation echoes corresponding to high-reflectivity objects before data fusion, effectively filtering out point clouds corresponding to point cloud dilatation, thereby reducing the impact of point cloud dilatation on the object recognition capability of lidar and improving the object recognition accuracy of lidar. 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 diagram of the structure of a lidar according to an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of point cloud expansion that occurs when a lidar detects a highly reflective object;

[0043] Figure 3 This is a schematic diagram illustrating the implementation flow of an echo data processing method provided in an embodiment of this application;

[0044] Figure 4 This is a schematic diagram illustrating the specific implementation flow of S12 in the method provided in the embodiments of this application;

[0045] Figure 5 This is a schematic diagram of another lidar structure provided in an embodiment of this application;

[0046] Figure 6 This is a schematic diagram comparing the echo waveforms of objects with high reflectivity and those with low reflectivity.

[0047] Figure 7 This is a schematic diagram illustrating the process of filtering echo waveforms corresponding to highly reflective objects in the method provided in the embodiments of this application;

[0048] Figure 8 This is a schematic diagram showing the correspondence between the transmitting module and the receiving module of a lidar provided in an embodiment of this application;

[0049] Figure 9 This is a schematic diagram of the limit filtering process in the method provided in the embodiments of this application;

[0050] Figure 10 This describes the distribution of point cloud data after processing by the echo data processing method provided in this application embodiment;

[0051] Figure 11 This is a schematic diagram of the structure of an echo data processing device provided in an embodiment of this application;

[0052] Figure 12 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application;

[0053] Figure 13 This is a schematic diagram of the structure of a chip provided in an embodiment of this application. Detailed Implementation

[0054] 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.

[0055] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations. Furthermore, in the description of this application specification and the appended claims, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0056] It should also be understood that references to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include the specific features, structures, or characteristics 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.

[0057] LiDAR (Light Detection and Ranging) is a radar system that uses laser beams to detect the position, velocity, and other information of targets. Besides detecting the distance to objects, it can also detect the reflectivity of objects used for target identification. The specific working principle of LiDAR is to emit a detection signal towards the target. After reaching the target, the detection signal is reflected by the target object, forming echo data. LiDAR receives the reflected signal (echo data) and then determines relevant information about the target based on the echo data, such as the target's distance, position, altitude, velocity, attitude, shape, and reflectivity, thereby achieving target detection, target tracking, and target identification. The reflectivity of an object refers to the percentage of radiated energy reflected by the object to the total radiated energy of the incident signal. Different objects have different reflectivities, which are mainly determined by factors such as the object's surface properties, the wavelength of the incident signal, and the angle of incidence.

[0058] In practical applications, based on the ranging method, lidar can be divided into time-of-flight (ToF) ranging, frequency-modulated continuous wave (FMCW) ranging, and triangulation ranging. Among these, the time-of-flight (TOF) ranging method involves emitting a series of infrared light (or laser pulses) invisible to the human eye, reflecting off an object, and calculating the time difference or phase difference between emission and reflection back to the radar to determine the object's distance.

[0059] For example, please refer to Figure 1, Figure 1 A schematic diagram of a lidar structure is shown. Figure 1 As shown, a lidar 10 typically includes a transmitting module 11, a scanning system 12, a receiving module 13, and a data processing system 14. The transmitting module 11 may include a light source system 111.

[0060] The light source system 111 generates the laser beam required for detection by the lidar 10. Specifically, the light source system 111 may include optical devices such as a laser and an emitting lens group. The scanning system 12 deflects the laser beam generated by the light source system 111, allowing the laser beam to hit different positions at different times. The scanning system 12 can be a mechanical scanning system (i.e., a rotary drive platform) or a semi-solid-state scanning system (i.e., a rotating mirror, a galvanometer, or a combination of both). This application does not impose a unique limitation on the form of the scanning system. It is understood that the lidar in this application can also be a solid-state lidar, i.e., scanning is achieved by controlling light sources at different angles to emit light sequentially. The scanning method of the lidar 10 can be a line scan or a block scan. A line scan refers to a scanning method in which the transmitting block in the transmitting module emits one block at a time, and the receiving block in the receiving module receives the entire line. A one-to-one block scan refers to a scanning method in which the transmitting block in the transmitting module emits one block at a time, and the corresponding receiving block in the receiving module receives the corresponding block at a time.

[0061] After the laser beam emitted by the light source system reaches the target object, it is reflected by the target object. The reflected light pulse is received by the receiving sensor 131 in the receiving module 13. Then, the echo signal processing circuit processes the echo signal to generate corresponding detection information.

[0062] It should be noted that the aforementioned light source system can use devices such as vertical cavity surface emitting lasers (VCSELs) or edge emitting lasers (EELs). The aforementioned sensor can be composed of a single photon avalanche diode (SPAD) array or a silicon photomultiplier (SiPM). A SiPM is composed of a large number (typically hundreds to thousands) of SPAD units. Each SPAD unit consists of a SPAD and a high-resistance quenching resistor connected in series. These SPAD units are connected in parallel to form a surface array (i.e., the aforementioned SiPM). When the lidar detects a highly reflective object, point cloud expansion occurs. This is because highly reflective objects reflect a much larger amount of energy, more than 100 times that of normally reflective objects, causing the point cloud data to diffuse or expand during generation, thus affecting the lidar's ability to identify objects.

[0063] For example, please refer to Figure 2 , Figure 2 This diagram illustrates point cloud expansion that occurs when a lidar detects a highly reflective object. Figure 2 As shown, point cloud dilation can cause objects around highly reflective objects to be covered, making them undetectable. Point cloud dilation affects the ability of LiDAR to identify objects.

[0064] Based on this, embodiments of this application provide an echo data processing method. By filtering out high-inflection dilation data from multiple scans of echo data and then performing data fusion, the impact of point cloud dilation on the object recognition capability of the lidar is reduced, thereby improving the object recognition accuracy of the lidar.

[0065] The echo data processing method provided in the embodiments of this application will be described in detail below:

[0066] Please see Figure 3 , Figure 3 The implementation flow of an echo data processing method provided in an embodiment of this application is illustrated. For example... Figure 3 As shown, the above echo data processing method may specifically include S11 to S12.

[0067] It should be noted that the execution subject of the echo data processing method provided in this application embodiment can be the aforementioned lidar 10, specifically the data processing system within the lidar 10. Of course, the execution subject of the aforementioned echo data processing method can also be a terminal device communicatively connected to the lidar 10. This terminal device can be a mobile phone, desktop computer, laptop computer, tablet computer, or wearable device, or it can be a cloud server, radar-assisted computer, or other devices in various application scenarios. This application does not impose specific limitations in this regard. The following explanation uses the lidar 10 as the execution subject as an example:

[0068] In S11, echo data corresponding to multiple scans are acquired, and echo characteristics are determined based on the echo data.

[0069] The above echo data is obtained by lidar based on multiple scans.

[0070] In practical applications, lidar can scan a target multiple times and then fuse the echo data obtained from the multiple scans to identify the target based on the fused echo data.

[0071] In practical applications, the aforementioned echo characteristics may include, but are not limited to, echo peak value, echo width, received pixel range, distance value corresponding to the echo, and echo area.

[0072] In S12, the target echo data is determined based on the echo characteristics of the current scan and the echo characteristics of the previous scan.

[0073] In practical applications, the target echo data mentioned above refers to the echo data after filtering out echoes with high inverse dilation. It can be understood that the target echo data mentioned above is the echo data used during data fusion.

[0074] In practical applications, lidar can filter echo data corresponding to high anti-expansion echoes before data fusion based on the echo characteristics corresponding to echoes from multiple scans.

[0075] In one implementation, the lidar can determine whether there is a high-inflection-expansion echo in the echoes of two scans. If it exists, the echo data corresponding to the scan with the smaller echo area is selected as the target echo data. If there is no high-inflection-expansion echo, the echo data corresponding to the scan with the larger echo area is selected as the target echo data. If the area difference between the two scans is small and the distance difference is small, the average of the corresponding echo data of the two scans can be used as the target echo data.

[0076] In another implementation, for single-point scanning, the lidar can determine whether there is a high-inflection-expansion echo in the echoes of two scans. If it exists, the echo data corresponding to the scan with lower transmission power is selected as the target echo data; if it does not exist, the echo data corresponding to the scan with higher transmission power is selected as the target echo data. If the absolute difference between the transmission power of the current scan and the transmission power of the previous scan is less than a preset power difference threshold, or the absolute difference between the distance value corresponding to the echo of the current scan and the distance value corresponding to the echo of the previous scan is less than a distance difference threshold, then the average of the echo data of the current scan and the echo data of the previous scan is used as the target echo data.

[0077] In some embodiments of this application, such as Figure 4 As shown, the above S12 may specifically include the following steps:

[0078] S401: Determine whether the echo area of ​​the current scan is greater than or equal to the preset echo area threshold. If yes, execute S402; otherwise, fuse the echo data from the two scans.

[0079] S402: Determine whether the absolute value of the difference between the echo area value of the current scan and the echo area value of the previous scan is greater than or equal to a preset area difference threshold, or whether the absolute value of the difference between the distance value corresponding to the echo of the current scan and the distance value corresponding to the echo of the previous scan is greater than or equal to a preset distance difference threshold. If so, execute S403; otherwise, execute S410.

[0080] In practical applications, the distance value corresponding to the echo of the above scan can be determined by the echo width or echo time.

[0081] S403: Determine whether the echo area value of the current scan is greater than the echo area value of the previous scan. If yes, execute S404; otherwise, execute S407.

[0082] S404: Determine whether the echo area value of the current scan is greater than the high anti-dilation threshold, whether the echo area value of the previous scan is greater than the absolute threshold of the area value, and whether the distance value corresponding to the echo of the previous scan is not 0. If so, execute S405; otherwise, execute S406.

[0083] S405: The echo data from the previous scan is identified as the target echo data.

[0084] S406: Determine the echo data of the current scan as the target echo data.

[0085] S407: Determine whether the scan area value of the previous scan is greater than the absolute area threshold and whether the distance value corresponding to the echo of the previous scan is not 0. If so, execute S408; otherwise, execute S409.

[0086] S408: Identify the echo data from the previous scan as the target echo data.

[0087] S409: Determine the echo data of the current scan as the target echo data.

[0088] S410: The average of the echo data from the two scans is determined as the target echo data.

[0089] In S13, the target echo data is fused to perform target identification based on the fused target echo data.

[0090] In practical applications, after determining the target echo data, the lidar can fuse the echo data after filtering out high-reflection expansion echoes. Specifically, it can fuse the target echo data determined in the first two scans with the target echo data determined in the second two scans to obtain the first fusion result. Then, it can fuse the first fusion result with the target echo data determined in the third two scans to obtain the second fusion result, and so on, until the target echo data obtained in the last two scans is fused to obtain the final fusion result. Of course, the echo data can also be fused in parallel, that is, after determining all target echo data, all target echo data are fused together. Of course, echo data fusion can also be performed using a combination of serial and parallel methods. This involves fusing the target echo data determined by the first two scans with the target echo data determined by the second two scans to obtain the first fusion result. Then, the target echo data determined by the third two scans with the target echo data determined by the fourth two scans to obtain the second fusion result. This process is repeated until all target echo data is fused.

[0091] By recovering the echo waveform based on the fusion result, information such as the distance and appearance parameters of the target object can be determined, thereby enabling target recognition. This part can refer to existing echo waveform recovery methods and distance determination algorithms, and this application will not elaborate on it further.

[0092] As can be seen from the above, the echo data processing method provided in this application embodiment can filter out the high-reflectivity dilation echoes corresponding to high-reflectivity objects before data fusion in the process of data fusion, effectively filtering out the point clouds corresponding to point cloud dilation, thereby reducing the impact of point cloud dilation on the object recognition capability of the lidar and improving the object recognition accuracy of the lidar.

[0093] In one embodiment of this application, the echo data processing method may further include the following steps before S12:

[0094] The echo peak value and echo width of each echo are determined based on the detection results;

[0095] If the echo peak value is greater than or equal to the peak value threshold and the echo width is greater than or equal to the width threshold, then the echo is determined to be the echo corresponding to a high reflectivity object.

[0096] The echo data corresponding to objects with high reflectivity is filtered out from the echo data to obtain the echo data after detection and filtering.

[0097] For example, such as Figure 5 As shown, the aforementioned lidar may include a detection module 51, a limiting filter module 52, a fusion processing module 53, and a storage module 54.

[0098] The detection module 51 is used to detect the echo waveform based on the echo data and determine echo characteristics such as echo peak value and echo width.

[0099] Each echo represents a different object, and the echo peak value and echo width corresponding to each echo can be obtained through the detection module 51.

[0100] Please see Figure 6 , Figure 6 This diagram illustrates a comparison between the echo waveforms of highly reflective objects and those of non-highly reflective objects. Echoes 1, 2, and 3 represent the echo waveforms of non-highly reflective objects, while echo 4 represents the echo waveform of a highly reflective object. Figure 6 It can be seen that objects with high reflectivity have a larger echo width and a higher echo peak.

[0101] After the lidar detects the echo waveform in the detection module 51, it can perform high-reflectivity filtering on the echo data based on the peak value and width of the detected echo waveform. This means filtering out the echo data corresponding to objects with high reflectivity and retaining the echo data corresponding to objects with low reflectivity.

[0102] In practical applications, peak threshold and width threshold can be preset. The lidar can compare the determined echo peak with the peak threshold and the determined echo width with the width threshold. If the echo peak is greater than or equal to the peak threshold and the echo width is greater than or equal to the width threshold, the echo can be identified as the echo corresponding to a high reflectivity object, and therefore the echo can be filtered.

[0103] It should be noted that the echo waveform detected by the detection module 51 will differ depending on the distance between the object and the lidar. For example, ... Figure 6 The echo waveform shown is 1 for near-field objects, 2 for mid-to-long-field objects, and 3 for far-field objects. Therefore, to improve the detection accuracy of echoes from highly reflective objects, different peak and width thresholds can be set for different distances.

[0104] For example, please refer to Figure 7 , Figure 7 This diagram illustrates the process by which the detection module 51 provided in this embodiment filters the echo waveform corresponding to a high-reflectivity object. Figure 7 As shown, the entire reception time is divided into three time intervals (corresponding to different distance values). The first time interval TOF1 is set with the first peak threshold csr_satu_peak1 and the first width threshold csr_max_width1. The second time interval TOF2 is set with the second peak threshold csr_satu_peak2 and the second width threshold csr_max_width2. The third time interval TOF3 is set with the third peak threshold csr_satu_peak3 and the third width threshold csr_max_width3.

[0105] For echoes within different time intervals, corresponding thresholds can be used to determine whether the echo data corresponding to that echo should be filtered.

[0106] For example, for echo 1 within the first time interval, the peak value of echo 1 (echo_peak1) can be compared with the first peak value threshold (csr_satu_peak1), and the echo width of echo 1 (echo_width1) can be compared with the first width threshold (csr_max_width1). If echo_peak1 >= csr_satu_peak1 and echo_width1 >= csr_max_width1, then the echo data corresponding to echo 1 is filtered out; otherwise, the data of echo 1 is retained.

[0107] For echo 2, which is located in the second time interval, the peak value of echo 2 (echo_peak2) can be compared with the first peak value threshold (csr_satu_peak2), and the echo width of echo 2 (echo_width2) can be compared with the first width threshold (csr_max_width2). If echo_peak2 >= csr_satu_peak2 and echo_width2 >= csr_max_width2, then the echo data corresponding to echo 2 is filtered out; otherwise, the data of echo 2 is retained.

[0108] For echo 3, which is located in the third time interval, the peak value of echo 3 can be compared with the first peak value threshold csr_satu_peak3, and the echo width of echo 3 can be compared with the first width threshold csr_max_width3. If echo_peak3 >= csr_satu_peak3 and echo_width3 >= csr_max_width3, then the echo data corresponding to echo 3 is filtered out; otherwise, the data of echo 3 is retained.

[0109] It should be noted that the aforementioned first peak threshold, first width threshold, second peak threshold, second width threshold, third peak threshold, and third width threshold can be set according to the actual application scenario and actual measurement results. For example, in applications involving the measurement of near-field objects, these thresholds can all be set to thresholds related to the echo characteristics of the near-field object. This allows for the filtering out of echo data that does not belong to the near-field object, while retaining the echoes of the near-field object of interest. The settings of these thresholds can also be related to the relevant parameters of the transmitter and receiver. For instance, if the transmitter has a higher transmission energy, the thresholds can be increased accordingly.

[0110] It should also be noted that dividing the entire reception time into three time intervals is only one example of implementation. In other embodiments, the reception time can be divided into four, five, or other time intervals. The finer the division of the reception time, the more accurate the echo filtering for highly reflective objects, but it also requires more computational resources. Therefore, the number of intervals for the reception time can be set by considering both the measurement accuracy requirements of the lidar and the computing power level.

[0111] In some embodiments of this application, since the echo area of ​​a high-reflectivity object is very large, but the large echo area caused by point cloud expansion is not worth processing, the echo data can be saturated and truncated based on the echo area before high-reflectivity filtering. This can be achieved by setting a preset component bit width and saturating and truncating data greater than or equal to the preset component bit width. For example, if the preset component bit width is 16 bits, then data greater than or equal to 16 bits will be saturated and truncated using ffff, and the truncated echo data will be transmitted to the subsequent module for relevant high-reflectivity filtering, thereby saving computational logic related to the echo area and conserving computational resources.

[0112] It should be noted that the aforementioned post-stage modules refer to the functional modules in the lidar that process the echo data, such as the aforementioned detection module, the aforementioned limit filtering module, the aforementioned fusion processing module, and the noise processing module.

[0113] In one embodiment of this application, the aforementioned echo data may also be echo data received by the lidar after it performs transmit and receive control based on a preset scanning method. The aforementioned preset scanning method refers to a scanning method in which the lidar's transmitting laser emits detection signals block by block, and the echo signals are received by a receiving unit group corresponding to the transmitting block, wherein the receiving unit group includes at least two receiving units.

[0114] In practical applications, the echo signal formed by the detection signal emitted by one transmitting block can be received simultaneously by at least two receiving units. That is, redundant receiving units are set in the preset scanning method of this application embodiment.

[0115] It should be noted that the redundancy of the aforementioned receiving units can be set based on the distance deviation between the transmitting laser in the transmitting module and the receiving array in the receiving module, as well as the angle of the transmitted laser. For example, the offset of the received echo beam is determined by the distance deviation between the transmitting laser and the receiving array and the angle of the transmitted laser. The greater the distance deviation between the transmitter and receiver, the greater the offset of the target echo on the receiving array, and therefore the greater the number of redundant receiving units can be.

[0116] When a detection signal detects a highly reflective object, if only one receiver block is used to receive the echo signal, the received signal will most likely be completely covered by the echo signal reflected by the highly reflective object. However, by setting up redundant receiver units, the redundant receiver units have the opportunity to receive echo signals reflected by other objects that are not covered by the echo reflected by the highly reflective object, thereby increasing the richness of the received echo signal. This allows the lidar to use the echo data with the least severe point cloud expansion for ranging and object recognition in subsequent steps, thus reducing the impact of point cloud expansion on the lidar's object recognition capability.

[0117] For example, please refer to Figure 8 , Figure 8 This is a schematic diagram illustrating the correspondence between the transmitting module and the receiving module of a lidar, provided in an embodiment of this application. Figure 8 The following example illustrates a lidar system comprising two transmitters and a SPAD array for receiving signals.

[0118] like Figure 8 As shown, the receiving unit group corresponding to the first transmitting block LD11 in the first transmitter VCSEL1 may include receiving block 1 and receiving block 2, and the receiving unit group corresponding to the first transmitting block LD21 in the second transmitter VCSEL2 may include receiving block 3 and receiving block 4. After the first transmitting block LD11 in the first transmitter VCSEL1 completes its transmission, the lidar controls the second transmitting block LD12 in the first transmitter VCSEL to transmit a detection signal. At this time, receiving blocks 2 and 5 in the receiving array, as the receiving unit group corresponding to the second transmitting block LD12 in the first transmitter VCSEL, will receive the echo data.

[0119] by Figure 8 Taking the correspondence between the transmitting and receiving modules shown as an example, the scanning of the above-mentioned lidar according to the preset scanning method can be as follows: The lidar controls the first transmitting block LD11 in the first transmitter VCSEL1 to transmit a detection signal (referred to as the first detection signal), and correspondingly controls the receiving blocks 1 and 2 in the receiving SPAD array to receive the echo signal corresponding to the first detection signal. At the same time, it can control the first transmitting block LD21 in the second transmitter VCSEL2 to transmit a detection signal (referred to as the second detection signal), and correspondingly controls the receiving blocks 3 and 4 in the receiving SPAD array to receive the echo signal corresponding to the second detection signal. After completion, the lidar can then control the second transmitting block LD12 in the first transmitter VCSEL1 to transmit a detection signal (referred to as the third detection signal), and correspondingly controls the receiving blocks 2 and 5 in the receiving SPAD array to receive the echo signal corresponding to the third detection signal. It can then control the second transmitting block LD22 in the second transmitter VCSEL2 to transmit a detection signal (referred to as the fourth detection signal), and correspondingly controls the receiving blocks 4 and 6 in the receiving SPAD array to receive the echo signal corresponding to the fourth detection signal. This process continues until all blocks have completed their transmission and reception.

[0120] It should be noted that, Figure 8 This application uses a dual-emitter example for illustration only. The lidar in this embodiment can also be a single-emitter lidar or a multi-emitter lidar. This application does not impose any specific restrictions on this.

[0121] As can be seen above, by acquiring the echo data received by the target receiving unit group with redundant receiving units, and performing feature extraction based on the echo data, the identification and filtering of high reflectivity echoes can be achieved. This can effectively filter the point cloud corresponding to point cloud expansion, thereby reducing the impact of point cloud expansion on the object recognition capability of the lidar and improving the object recognition accuracy of the lidar.

[0122] In one embodiment of this application, the procedure before S12 may further include:

[0123] High-inflection filtering is applied to the echo data based on the effective data range.

[0124] In practical applications, the above-mentioned high-reflection filtering of echo data based on the effective data range can be performed by... Figure 5 The limit filtering module 52 in the middle is used to perform the operation.

[0125] In practical applications, the echo signal corresponding to the detection signal emitted by the LiDAR transmitter is received by the receiving unit corresponding to the transmitter's transmitting unit. Specifically, it can be received within the effective receiving range of the receiving unit. For objects with high reflectivity, the echo signal corresponding to the detection signal has greater energy, thus widening the received echo area. However, the effective receiving range remains unchanged. Therefore, echoes larger than or equal to the effective receiving range can be considered invalid echoes caused by point cloud expansion, and thus can be filtered.

[0126] It should be noted that the receiving module (specifically, a receiving array) may include multiple receiving units (or receiving blocks), and each receiving block may include multiple receiving pixels, meaning that a receiving pixel is a smaller receiving unit within a receiving block. For example, a receiving block may include 8*4 receiving pixels. After the transmitter of the transmitting module transmits a detection signal, the receiving pixels within the effective receiving range of the receiving block in the receiving array can receive the echo signal.

[0127] In one embodiment of this application, the above-mentioned high-reflection filtering of echo data based on the effective data range may specifically include the following steps:

[0128] Based on the distance value corresponding to the echo data and the position of the LiDAR transmitter block, the range of received pixels in the effective reception interval is determined from the effective reception interval table.

[0129] If the reception range of the echo exceeds the reception pixel range of the above effective reception interval, then the corresponding echo data within the effective reception interval will be output.

[0130] If the reception range of the echo is within the reception pixel range of the above-mentioned effective reception interval, then all echo data will be output.

[0131] In practical applications, the above-mentioned effective reception interval table can be determined in advance through actual measurements. Each lidar can be set with a corresponding effective reception interval table. The range of received pixels in the corresponding effective reception interval under different transmitter positions and scanning distances can be determined through calibration tests.

[0132] This means that the radar transmitter and scanning distance can be used as indexes to determine the range of received pixels in the effective receiving interval corresponding to the current transmitter and the current scanning distance from the effective receiving interval table.

[0133] Then, the receiving range of the echo is compared with the receiving pixel range of the effective receiving interval. Assuming the receiving pixel range of the effective receiving interval is [pix_num_min, pix_num_max], if the receiving range of the current echo is less than pix_num_min or greater than pix_num_max, it is determined that the receiving range of the echo exceeds the receiving pixel range of the effective receiving interval; otherwise, it is determined that the receiving range of the echo is within the receiving pixel range of the effective receiving interval.

[0134] In practical applications, the above effective reception range table can include entries corresponding to different distance levels. For example, assuming that the distance range uses 64 levels, each transmitter block needs 64 entries, and the lookup index is the transmitter block location number and the distance value corresponding to the echo.

[0135] For example, please refer to Figure 9 , Figure 9 A schematic diagram of the limit filtering process is shown. Figure 9 As shown, after inputting the distance value corresponding to the echo and the transmitter block position number, the distance setting corresponding to the echo can be determined. Then, based on the distance setting and the transmitter block position number, the effective reception interval table is searched to determine the range of received pixels within the effective reception interval, including the upper limit value pix_num_max and the lower limit value pix_num_min. It is then determined whether the reception range of the echo is less than the lower limit value pix_num_min and greater than the upper limit value pix_num_max. If the reception range is less than pix_num_min or greater than pix_num_max, 0 is output; otherwise, the echo data corresponding to the echo is output.

[0136] As can be seen from the above, the echo data processing method provided in this application can effectively filter the point cloud corresponding to point cloud expansion by acquiring the echo data received by the target receiving unit group with redundant receiving units, extracting features based on the echo data, and identifying and filtering high reflectivity echoes in the limiting filtering process, thereby reducing the impact of point cloud expansion on the object recognition capability of the lidar and improving the object recognition accuracy of the lidar.

[0137] Figure 10 This illustrates the distribution of point cloud data processed by the echo data processing method provided in this embodiment of the application. Figure 10 It can be seen that the echo data processing method provided in the embodiments of this application can effectively suppress the point cloud expansion caused by high reflectivity objects.

[0138] It should be noted that the point cloud data processed by the echo data processing method provided in this application embodiment can be stored in the above-mentioned storage module 54.

[0139] 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.

[0140] Based on the echo data processing method provided in the above embodiments, the present invention further provides an embodiment of an echo data processing apparatus for implementing the above method embodiments.

[0141] Please see Figure 11 , Figure 11 This is a schematic diagram of an echo data processing device provided in an embodiment of this application. In this embodiment, the echo data processing device includes units used for performing... Figure 3 The steps in the corresponding embodiments. Please refer to the details. Figure 3 as well as Figure 3 The relevant descriptions in the corresponding embodiments are shown below. For ease of explanation, only the parts relevant to this embodiment are shown. Figure 11 As shown, the echo data processing device 110 may include an acquisition unit 1101, a determination unit 1102, and a fusion unit 1103, wherein:

[0142] The acquisition unit 1101 is used to acquire echo data corresponding to multiple scans and determine echo characteristics based on the echo data.

[0143] The determining unit 1102 is used to determine the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan; the target echo data is the echo data after filtering out the high back-expansion echo.

[0144] The fusion unit 1103 is used to fuse the target echo data in order to identify the target based on the fused target echo data.

[0145] In some implementations, the echo feature includes the echo area. Specifically, the determining unit is used to: if there is an echo with high back expansion in the echo of the current scan or the echo of the previous scan; then use the echo data with the smaller echo area as the target echo data; if there is no echo with high back expansion in the echo of the current scan or the echo of the previous scan; then use the echo data with the larger echo area as the target echo data; if the absolute difference between the echo area of ​​the current scan and the echo area of ​​the previous scan is less than a preset area difference threshold, or the absolute difference between the distance value corresponding to the echo of the current scan and the distance value corresponding to the echo of the previous scan is less than a distance difference threshold, then use the average of the echo data of the current scan and the echo data of the previous scan as the target echo data.

[0146] In some implementations, where the echo characteristics are affected by the transmission power, the aforementioned determining unit is specifically used to determine the echo data corresponding to the scan with low transmission power as the target echo data if there is a high anti-expansion echo in the echo of the current scan or the echo of the previous scan.

[0147] If there is no high-inflection-expansion echo in the current scan or the previous scan, then the echo data corresponding to the scan with high transmission power will be determined as the target echo data.

[0148] If the absolute difference between the transmit power of the current scan and the transmit power of the previous scan is less than a preset power difference threshold, or if the absolute difference between the distance value corresponding to the echo of the current scan and the distance value corresponding to the echo of the previous scan is less than a distance difference threshold, then the average of the echo data of the current scan and the echo data of the previous scan will be used as the target echo data.

[0149] In some implementations, the echo data processing device 110 may also include a detection and filtering unit.

[0150] The aforementioned detection and filtering unit is specifically used to determine the echo peak value and echo width of each echo based on the detection results; if the echo peak value is greater than or equal to the peak value threshold and the echo width is greater than or equal to the width threshold, then the echo is determined to be the echo corresponding to a high reflectivity object; the echo data corresponding to the high reflectivity object is filtered out from the echo data to obtain the echo data after detection and filtering.

[0151] In some implementations, the aforementioned detection and filtering unit can be used to determine the peak threshold and width threshold of the time interval in which the echo is located, wherein different peak thresholds and width thresholds are set for different time intervals;

[0152] If the echo peak value is greater than or equal to the peak threshold value corresponding to the time interval in which the echo is located, and the echo width is greater than or equal to the width threshold value corresponding to the time interval in which the echo is located, then the echo is determined to be an echo corresponding to a high reflectivity object.

[0153] In some implementations, the echo data processing device 110 may also include a limiting filter unit.

[0154] The aforementioned limiting filter unit is used to perform high-inflection filtering on the echo data based on the effective data range.

[0155] In some implementations, the aforementioned limiting filter unit is specifically used to determine the receiving pixel range of the effective receiving interval from the effective receiving interval table based on the distance value corresponding to the echo and the position of the LiDAR transmitter block; if the receiving range of the echo exceeds the receiving pixel range of the effective receiving interval, the corresponding echo data within the effective receiving interval is output; if the receiving range of the echo is within the receiving pixel range of the effective receiving interval, all echo data is output.

[0156] The aforementioned echo data processing apparatus may further include a saturation truncation unit, which is used to saturate truncate the echo data based on the echo area of ​​the echo.

[0157] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. Their specific functions and technical effects can be referred to the method embodiments section, and will not be repeated here.

[0158] Therefore, the echo data processing method provided in this application embodiment is...

[0159] Figure 12 This is a schematic diagram of the structure of a terminal device provided in another embodiment of this application. For example... Figure 12 As shown, the terminal device 12 provided in this embodiment includes: a processor 120, a memory 121, and a computer program 122 stored in the memory 121 and executable on the processor 120, such as an image segmentation program. When the processor 120 executes the computer program 122, it implements the steps in the various echo data processing method embodiments described above, for example... Figure 3 S11 to S12 are shown. Alternatively, when the processor 120 executes the computer program 122, it implements the functions of each module / unit in the above-described terminal device embodiments, for example... Figure 11 The functions of units 1101 to 1102 shown.

[0160] For example, the computer program 122 described above can be divided into one or more modules / units. One or more of these modules / units are stored in the memory 121 and executed by the processor 120 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 122 in the terminal device 12. For example, the computer program 122 can be divided into an acquisition unit, a determination unit, and a calculation unit. For the specific functions of each unit, please refer to [link to relevant documentation]. Figure 7 The relevant descriptions in the corresponding embodiments are not repeated here.

[0161] The aforementioned terminal device may include, but is not limited to, a processor 120 and a memory 121. Those skilled in the art will understand that... Figure 12 This is merely an example of terminal device 12 and does not constitute a limitation on terminal device 12. It may include more or fewer components than shown, or combine certain components, or different components. For example, the terminal device described above may also include input / output devices, network access devices, buses, etc.

[0162] The processor 120 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0163] The aforementioned memory 121 can be an internal storage unit of the terminal device 12, such as a hard disk or RAM of the terminal device 12. The aforementioned memory 121 can also be an external storage device of the terminal device 12, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the terminal device 12. Furthermore, the aforementioned memory 121 can include both internal and external storage units of the terminal device 12. The aforementioned memory 121 is used to store the aforementioned computer program and other programs and data required by the terminal device. The aforementioned memory 121 can also be used to temporarily store data that has been output or will be output.

[0164] This application also provides a computer-readable storage medium. Please refer to... Figure 13 , Figure 13 This is a schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of this application, such as... Figure 13 As shown, a computer program 122 is stored in the computer-readable storage medium 130. When the computer program 122 is executed by the processor, it can implement the above-described echo data processing method.

[0165] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the aforementioned echo data processing method.

[0166] 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 terminal 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.

[0167] 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, refer to the relevant descriptions of other embodiments.

[0168] 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.

[0169] The above 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. An echo data processing method, characterized in that, include: Acquire echo data corresponding to multiple scans, and determine echo characteristics based on the echo data; The target echo data is determined based on the echo characteristics of the current scan and the echo characteristics of the previous scan; the target echo data is the echo data after filtering out echoes with high anti-expansion. The target echo data is fused to perform target identification based on the fused target echo data.

2. The echo data processing method according to claim 1, characterized in that, The echo features include the echo area. Determining the target echo data based on the echo features of the current scan and the echo features of the previous scan includes: If there is a high-inflection-expansion echo in the current scan or the echo in the previous scan, then the echo data corresponding to the scan with the smaller echo area is determined as the target echo data. If there is no echo with high anti-expansion in the echo of the current scan or the echo of the previous scan, then the echo data corresponding to the scan with the larger echo area is determined as the target echo data. If the absolute difference between the echo area of ​​the current scan and the echo area of ​​the previous scan is less than a preset area difference threshold, or if the absolute difference between the distance value corresponding to the echo of the current scan and the distance corresponding to the echo of the previous scan is less than a distance difference threshold, then the average of the echo data of the current scan and the echo data of the previous scan will be used as the target echo data.

3. The echo data processing method according to claim 1, characterized in that, The echo characteristics include the transmission power. Determining the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan includes: If there is a high-inflection-expansion echo in the current scan or the echo of the previous scan, then the echo data corresponding to the scan with low transmission power will be determined as the target echo data. If there is no high-inflection-expansion echo in the current scan or the previous scan, then the echo data corresponding to the scan with high transmission power will be determined as the target echo data. If the absolute difference between the transmit power of the current scan and the transmit power of the previous scan is less than a preset power difference threshold, or if the absolute difference between the distance value corresponding to the echo of the current scan and the distance value corresponding to the echo of the previous scan is less than a distance difference threshold, then the average of the echo data of the current scan and the echo data of the previous scan will be used as the target echo data.

4. The echo data processing method according to any one of claims 1 to 3, characterized in that, Before determining the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan, the method further includes: The echo peak value and echo width of each echo are determined based on the detection results; If the echo peak value is greater than or equal to the peak value threshold and the echo width is greater than or equal to the width threshold, then the echo is determined to be an echo corresponding to a high reflectivity object. The echo data corresponding to objects with high reflectivity are filtered out from the echo data to obtain the echo data after detection and filtering.

5. The echo data processing method according to claim 4, characterized in that, After determining the echo peak value and echo width of each echo based on the detection results, the process also includes: Determine the peak threshold and width threshold for the time interval of the echo, where different peak thresholds and width thresholds are set for different time intervals; If the echo peak value is greater than or equal to the peak threshold value corresponding to the time interval in which the echo is located, and the echo width is greater than or equal to the width threshold value corresponding to the time interval in which the echo is located, then the echo is determined to be an echo corresponding to a high reflectivity object.

6. The echo data processing method according to any one of claims 1 to 4, characterized in that, The echo data is the echo data received by the lidar after it performs transmit and receive control based on a preset scanning method. The preset scanning method is a scanning method in which the lidar's transmitting laser emits detection signals block by block, and the receiving unit group corresponding to the transmitting block receives the echo signals. The receiving unit group includes at least two receiving units.

7. The echo data processing method according to claim 6, characterized in that, Before determining the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan, the method further includes: High-inflection filtering is applied to the echo data based on the effective data range.

8. The echo data processing method according to claim 7, characterized in that, The high-inflection filtering of the echo data based on the effective data range includes: Based on the distance value corresponding to the echo and the position of the LiDAR transmitter block, the range of received pixels in the effective reception interval is determined from the effective reception interval table. If the reception range of the echo exceeds the reception pixel range of the above-mentioned effective reception interval, then the corresponding echo data within the effective reception interval will be output. If the reception range of the echo is within the reception pixel range of the above-mentioned effective reception interval, then all echo data will be output.

9. An echo data processing device, characterized in that, include: An acquisition unit is used to acquire echo data corresponding to multiple scans and determine echo characteristics based on the echo data; The determining unit is used to determine the target echo data based on the echo characteristics of the current scan and the echo characteristics of the previous scan; the target echo data is the echo data after filtering out echoes with high back-expansion. The fusion unit is used to fuse the target echo data in order to perform target identification based on the fused target echo data.

10. 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 readable instructions of the computer program, it implements the echo data processing method as described in any one of claims 1 to 8.

11. A computer-readable storage medium storing a computer program, characterized in that, When the readable instructions of the computer program are executed by a processor, they implement the echo data processing method as described in any one of claims 1 to 8.

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