LiDAR data processing method, apparatus and computer-readable storage medium

Abstract

This application provides a lidar data processing method, apparatus, and computer-readable storage medium. The method includes: acquiring invalid locations, where the lidar cannot receive echoes; and constructing an invalid point grid map based on the invalid locations. The invalid point grid map is used to characterize the number of times and / or probability that the location corresponding to each grid is identified as an invalid location. That is, the locations where the lidar cannot receive echoes are first identified as invalid locations, and then the invalid point grid map is constructed based on the invalid locations. The invalid point grid map represents the number of times and / or probability that the location corresponding to each grid is an invalid location. It does not ignore the processing of reflective obstacles and solves the problem of insufficient accuracy in processing invalid locations of lidar in the prior art.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and more specifically, to a lidar data processing method, apparatus, computer-readable storage medium, and processor. Background Technology

[0002] In laser SLAM, invalid locations occur when the lidar is far from the target object, or when the target object's surface reflects light, causing the lidar to emit laser rays that cannot receive an echo. In existing technologies, invalid locations that do not receive an echo are considered to be at infinity. This ignores the handling of reflective obstacles, which is not conducive to map construction and will affect the positioning accuracy of mobile robots. Summary of the Invention

[0003] The main objective of this application is to provide a lidar data processing method, apparatus, computer-readable storage medium, and processor to solve the problem that the processing of invalid lidar positions is not accurate enough in the prior art.

[0004] To achieve the above objectives, according to one aspect of this application, a lidar data processing method is provided, the method comprising: acquiring invalid locations, wherein the invalid locations refer to locations where the lidar cannot receive echoes; and constructing an invalid point grid map based on the invalid locations, wherein the invalid point grid map is used to characterize the number of times and / or probability that the location corresponding to each grid is identified as the invalid location.

[0005] Further, obtaining invalid locations includes: obtaining an initial occupied grid map, which is used to characterize the probability that the location corresponding to each grid is occupied by an obstacle; and obtaining the invalid location based on the initial occupied grid map.

[0006] Further, based on the initial occupied grid map, obtaining the invalid location includes: obtaining the target location corresponding to the target grid that is not occupied by the obstacle based on the initial occupied grid map; obtaining the initial probability that an occupied grid with a distance less than a predetermined distance from the target grid is occupied by an obstacle based on the initial occupied grid map, wherein the occupied grid refers to a grid with an initial probability of being occupied by an obstacle greater than the predetermined probability; controlling a mobile device equipped with the lidar to move to the target location, and obtaining the echo signal of the laser emitted from the target location and reaching the occupied location corresponding to the occupied grid; and determining the invalid location based on the echo signal.

[0007] Further, determining the invalid location based on the echo signal includes: re-determining the occupancy probability corresponding to the occupied grid according to the echo signal, wherein the occupancy probability refers to the probability that the occupied grid is occupied by an obstacle; and if the occupancy probability is less than the initial probability, determining that there is an invalid location on the path from the target location to the occupied location.

[0008] Further, re-determining the occupancy probability corresponding to the occupied grid based on the echo signal includes: determining the distance information between the mobile device and the target location based on the echo signal; and determining the occupancy probability based on the distance information.

[0009] Furthermore, when the occupancy probability is less than the initial probability, determining that there is an invalid position on the path from the target position to the occupied position includes: determining the positions corresponding to grids that are simultaneously located on multiple paths as invalid positions.

[0010] Furthermore, the method further includes: updating the initial occupied grid map to obtain an updated occupied grid map; and updating the invalid point grid map to obtain an updated invalid point grid map.

[0011] Furthermore, after updating the invalid point grid map to obtain an updated invalid point grid map, the method further includes: fusing the updated occupied grid map and the updated invalid point grid map to obtain a fused grid map; constructing a laser SLAM map using the fused grid map; and / or performing navigation control.

[0012] According to another aspect of this application, a lidar data processing apparatus is also provided. The apparatus includes an acquisition unit and a construction unit. The acquisition unit is used to acquire invalid locations, which are locations where the lidar cannot receive echoes. The construction unit is used to construct an invalid point grid map based on the invalid locations. The invalid point grid map is used to characterize the number of times and / or the probability that the location corresponding to each grid is identified as the invalid location.

[0013] According to another aspect of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the methods described above.

[0014] According to another aspect of this application, a processor is also provided for running a program, wherein the program executes any of the methods described above during runtime.

[0015] By applying the technical solution of this application, invalid locations are obtained, where the lidar cannot receive echoes. Based on these invalid locations, an invalid point grid map is constructed. This invalid point grid map is used to characterize the number of times and / or the probability that the location corresponding to each grid is identified as an invalid location. That is, the locations where the lidar cannot receive echoes are first determined as invalid locations, and then an invalid point grid map is constructed based on these invalid locations. The invalid point grid map represents the number of times and / or the probability that the location corresponding to each grid is an invalid location. This approach does not ignore the handling of reflective obstacles and solves the problem of inaccurate handling of invalid lidar locations in the prior art. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A flowchart of a lidar data processing method according to an embodiment of this application is shown;

[0018] Figure 2 A schematic diagram of a lidar data processing apparatus according to an embodiment of this application is shown;

[0019] Figure 3 An occupancy grid map is shown in the case of no obstacles according to an embodiment of this application;

[0020] Figure 4 An occupancy grid map with obstacles is shown according to an embodiment of this application. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be an intermediate element present. Furthermore, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element via a third element.

[0025] As described in the background section, the existing technology does not accurately handle invalid positions of lidar. To solve the problem of inaccurate handling of invalid positions of lidar, the embodiments of this application provide a lidar data processing method, apparatus, computer-readable storage medium, and processor.

[0026] According to an embodiment of this application, a lidar data processing method is provided.

[0027] Figure 1 This is a flowchart of a lidar data processing method according to an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0028] Step S101: Obtain invalid locations. The aforementioned invalid locations refer to locations where the lidar cannot receive echoes.

[0029] Step S102: Based on the above invalid locations, construct an invalid point grid map. The invalid point grid map is used to characterize the number of times and / or probability that the location corresponding to each grid is identified as the above invalid location.

[0030] In the above steps, the locations where the lidar cannot receive echoes are first identified as invalid locations. Then, an invalid point grid map is constructed based on the invalid locations. The invalid point grid map represents the number of times and / or the probability that each grid corresponds to an invalid location. It does not ignore the processing of reflective obstacles and solves the problem of insufficient accuracy in processing invalid lidar locations in the prior art.

[0031] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0032] Specifically, map building includes the following steps: The mobile robot moves freely in an unknown environment and builds a map. Map building includes building a traditional occupied grid map (denoted as M) and the aforementioned invalid value grid map (denoted as N). The invalid value grid map can be built either during the construction of the occupied grid map M or after the occupied grid map is built. A threshold method is used to filter out some values ​​with higher probabilities in the invalid value grid map, and grids with probability values ​​greater than the threshold are recorded as invalid value candidate grids. Through these invalid value candidate grids, it is determined which points are points at infinity and which points are reflective obstacles. This can be directly determined by the connected component method, that is, if a candidate grid is surrounded by a connected white grid area (empty grid), then this candidate grid is definitely a reflective obstacle; otherwise, it is considered a point at infinity. Points at infinity usually appear at the edge of a wall. Then, the invalid value candidate grids are used to optimize the occupied grid map and the subsequent navigation process.

[0033] In one embodiment of this application, obtaining invalid locations includes: obtaining an initial occupied grid map, wherein the initial occupied grid map is used to characterize the probability that the location corresponding to each grid is occupied by an obstacle; and obtaining the invalid locations based on the initial occupied grid map. When applied to robot navigation, this can ensure that the mobile robot travels in places without obstacles.

[0034] Specifically, an initial occupied grid map is first obtained, which represents the probability that the position corresponding to each grid is occupied by an obstacle. Finally, based on the initial occupied grid map, the invalid positions are obtained, thus solving the problem that the processing of invalid positions of lidar in the prior art is not accurate enough.

[0035] In one embodiment of this application, obtaining the invalid location based on the initial occupied grid map includes: obtaining the target location corresponding to the target grid not occupied by the obstacle based on the initial occupied grid map; obtaining the initial probability that an occupied grid with a distance less than a predetermined distance from the target grid is occupied by an obstacle based on the initial occupied grid map, wherein the occupied grid refers to a grid with an initial probability of being occupied by an obstacle greater than the predetermined probability; controlling a mobile device equipped with the laser radar to move to the target location and obtaining the echo signal of the laser emitted from the target location and reaching the occupied location corresponding to the occupied grid; and determining the invalid location based on the echo signal. Specifically, the predetermined distance can be set to the distance of four grids, and the predetermined probability can be set to 80%. Of course, those skilled in the art can set appropriate predetermined distances and predetermined probabilities according to actual needs.

[0036] In one embodiment of this application, determining the invalid position based on the echo signal includes: re-determining the occupancy probability corresponding to the occupied grid according to the echo signal, where the occupancy probability refers to the probability that the occupied grid is occupied by an obstacle; if the occupancy probability is less than the initial probability, determining that there is an invalid position on the path from the target position to the occupied position. For example, if the occupancy probability is 40% and the initial probability is 80%, that is, the probability of the same grid being occupied has changed, and the probability has decreased. More accurately, the probability has decreased and the change is large, that is, from a state that is biased towards occupation to a state that is biased towards vacancy. This indicates that there is an invalid position on the path from the target position to the occupied position, that is, there is a reflective object on the path from the target position to the occupied position. When applied to robot navigation, this can ensure that the robot does not collide with obstacles.

[0037] In one embodiment of this application, re-determining the occupancy probability corresponding to the occupancy grid based on the echo signal includes: determining the distance information between the mobile device and the target location based on the echo signal; and determining the occupancy probability based on the distance information. That is, the distance information between the mobile device and the target location is first determined based on the echo signal, and then the occupancy probability is determined based on the distance information, which can realize the accurate determination of the occupancy probability in real-time navigation of the mobile device.

[0038] In one embodiment of this application, when the occupancy probability is less than the initial probability, determining that there is an invalid position on the path from the target position to the occupied position includes: determining the position corresponding to a grid that is simultaneously located on multiple paths as the invalid position. That is, when the same grid is simultaneously located on multiple paths (for example, simultaneously located on two or three paths), the probability of determining that the position corresponding to the grid is an invalid position is relatively high, thus further realizing the accurate determination of invalid positions.

[0039] In one embodiment of this application, the method further includes: updating the initial occupied grid map to obtain an updated occupied grid map; updating the invalid point grid map to obtain an updated invalid point grid map. By updating the initial occupied grid map and the invalid point grid map, the accuracy of invalid locations can be guaranteed.

[0040] In one embodiment of this application, after updating the invalid point grid map to obtain an updated invalid point grid map, the method further includes: fusing the updated occupied grid map and the updated invalid point grid map to obtain a fused grid map; constructing a laser SLAM map using the fused grid map; and / or performing navigation control. The fused grid map enables accurate construction of the laser SLAM map and accurate navigation of the mobile device.

[0041] This application also provides a lidar data processing device. It should be noted that the lidar data processing device of this application can be used to execute the lidar data processing method provided in this application. The lidar data processing device provided in this application is described below.

[0042] Figure 2 This is a schematic diagram of a lidar data processing apparatus according to an embodiment of this application. Figure 2 As shown, the device includes: an acquisition unit 10 and a construction unit 20;

[0043] The acquisition unit 10 is used to acquire invalid locations, which are locations where the lidar cannot receive echoes.

[0044] The construction unit 20 is used to construct an invalid point grid map based on the above invalid locations. The invalid point grid map is used to represent the number of times and / or the probability that the location corresponding to each grid is identified as an invalid location. That is, the location where the lidar cannot receive an echo is first determined as an invalid location, and then the invalid point grid map is constructed based on the above invalid locations. The invalid point grid map is used to represent the number of times and / or the probability that the location corresponding to each grid is an invalid location, which solves the problem that the processing of invalid lidar locations in the prior art is not accurate enough.

[0045] In one embodiment of this application, the acquisition unit includes a first acquisition module and a second acquisition module. The first acquisition module is used to acquire an initial occupied grid map, which is used to characterize the probability that the position corresponding to each grid is occupied by an obstacle. The second acquisition module acquires the invalid positions based on the initial occupied grid map. When applied to robot navigation, this can ensure that the mobile robot travels in a place without obstacles.

[0046] In one embodiment of this application, the second acquisition module includes a first acquisition submodule, a second acquisition submodule, a first processing submodule, a second processing submodule, and a third processing submodule. The first acquisition submodule acquires the invalid location based on the initial occupied grid map by: the second acquisition submodule acquiring the target location corresponding to a target grid not occupied by the obstacle based on the initial occupied grid map; the first processing submodule acquiring the initial probability that an occupied grid with a distance less than a predetermined distance from the target grid is occupied by an obstacle based on the initial occupied grid map, wherein the occupied grid refers to a grid with an initial probability of being occupied by an obstacle greater than the predetermined probability; the second processing submodule controlling a mobile device equipped with the laser radar to move to the target location and acquiring the echo signal of a laser emitted from the target location and reaching the occupied location corresponding to the occupied grid; and the third processing submodule determining the invalid location based on the echo signal. Specifically, the predetermined distance can be set to the distance of four grids, and the predetermined probability can be set to 80%. Of course, those skilled in the art can set appropriate predetermined distances and predetermined probabilities according to actual needs.

[0047] In one embodiment of this application, the third processing submodule includes a fourth processing submodule and a fifth processing submodule. The fourth processing submodule re-determines the occupancy probability corresponding to the occupied grid based on the echo signal. The occupancy probability refers to the probability that the occupied grid is occupied by an obstacle. The fifth processing submodule is used to determine that there is an invalid position on the path from the target position to the occupied position when the occupancy probability is less than the initial probability. For example, if the occupancy probability is 40% and the initial probability is 80%, that is, the probability of the same grid being occupied has changed, and the probability has decreased. More accurately, the probability has decreased and the change is large, that is, from a state that is biased towards occupation to a state that is biased towards idle. This indicates that there is an invalid position on the path from the target position to the occupied position, that is, there is a reflective object on the path from the target position to the occupied position. When applied to robot navigation, this can ensure that the robot does not collide with obstacles.

[0048] In one embodiment of this application, the fourth processing submodule includes a sixth processing submodule and a seventh processing submodule. The sixth processing submodule determines the distance information between the mobile device and the target location based on the echo signal. The seventh processing submodule determines the occupancy probability based on the distance information. That is, the distance information between the mobile device and the target location is first determined based on the echo signal, and then the occupancy probability is determined based on the distance information. This can achieve accurate determination of the occupancy probability in real-time navigation of the mobile device.

[0049] In one embodiment of this application, the fifth processing submodule includes an eighth processing submodule, which is used to determine the position corresponding to the grid that is simultaneously located on multiple of the above-mentioned paths as the invalid position. That is, when the same grid is simultaneously located on multiple paths (for example, simultaneously located on two or three paths), the probability of determining the position corresponding to the grid as an invalid position is relatively high, thus further realizing the accurate determination of invalid positions.

[0050] In one embodiment of this application, the device further includes a first processing unit and a second processing unit. The first processing unit is used to update the initial occupied grid map to obtain an updated occupied grid map; the second processing unit is used to update the invalid point grid map to obtain an updated invalid point grid map. By updating the initial occupied grid map and the invalid point grid map, the accuracy of invalid locations can be guaranteed.

[0051] In one embodiment of this application, the second processing unit includes a first processing module and a second processing module. The first processing module is used to update the invalid point grid map in the second processing unit. After obtaining the updated invalid point grid map, the updated occupied grid map and the updated invalid point grid map are merged to obtain a merged grid map. The second processing module uses the merged grid map to construct a laser SLAM map and / or to perform navigation control. Using the merged grid map can achieve accurate construction of the laser SLAM map and achieve accurate navigation of the mobile device.

[0052] The aforementioned lidar data processing device includes a processor and a memory. The aforementioned acquisition unit and construction unit are all stored in the memory as program units, and the processor executes the aforementioned program units stored in the memory to realize the corresponding functions.

[0053] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and adjusting kernel parameters can address the inaccurate handling of invalid locations in existing LiDAR technologies.

[0054] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0055] This invention provides a computer-readable storage medium including a stored program, wherein the program, when running, controls the device containing the computer-readable storage medium to execute the lidar data processing method.

[0056] This invention provides a processor for running a program, wherein the program executes the aforementioned lidar data processing method.

[0057] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it performs at least the following steps: obtaining invalid locations, where the invalid location refers to a location where the lidar cannot receive an echo; and constructing an invalid point grid map based on the invalid location, where the invalid point grid map is used to characterize the number of times and / or the probability that the location corresponding to each grid is identified as the invalid location.

[0058] Further, obtaining invalid locations includes: obtaining an initial occupied grid map, which is used to characterize the probability that the location corresponding to each grid is occupied by an obstacle; and obtaining the invalid location based on the initial occupied grid map.

[0059] Further, based on the initial occupied grid map, obtaining the invalid location includes: obtaining the target location corresponding to the target grid that is not occupied by the obstacle based on the initial occupied grid map; obtaining the initial probability that an occupied grid with a distance less than a predetermined distance from the target grid is occupied by an obstacle based on the initial occupied grid map, wherein the occupied grid refers to a grid with an initial probability of being occupied by an obstacle greater than the predetermined probability; controlling a mobile device equipped with the lidar to move to the target location, and obtaining the echo signal of the laser emitted from the target location and reaching the occupied location corresponding to the occupied grid; and determining the invalid location based on the echo signal.

[0060] Further, determining the invalid location based on the echo signal includes: re-determining the occupancy probability corresponding to the occupied grid according to the echo signal, wherein the occupancy probability refers to the probability that the occupied grid is occupied by an obstacle; and if the occupancy probability is less than the initial probability, determining that there is an invalid location on the path from the target location to the occupied location.

[0061] Further, re-determining the occupancy probability corresponding to the occupied grid based on the echo signal includes: determining the distance information between the mobile device and the target location based on the echo signal; and determining the occupancy probability based on the distance information.

[0062] Furthermore, when the occupancy probability is less than the initial probability, determining that there is an invalid position on the path from the target position to the occupied position includes: determining the positions corresponding to grids that are simultaneously located on multiple paths as invalid positions.

[0063] Furthermore, the method further includes: updating the initial occupied grid map to obtain an updated occupied grid map; and updating the invalid point grid map to obtain an updated invalid point grid map.

[0064] Furthermore, after updating the invalid point raster map to obtain an updated invalid point raster map, the method further includes: fusing the updated occupied raster map and the updated invalid point raster map to obtain a fused raster map; constructing a laser SLAM map using the fused raster map; and / or performing navigation control. The devices mentioned in this document can be servers, PCs, tablets, mobile phones, etc.

[0065] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0066] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0067] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0068] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0069] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0070] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0071] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0072] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, 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 process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0073] Example: This example relates to a lidar data processing scheme, which includes the following steps:

[0074] Step 1: Obtain the initial occupied grid map, which is used to represent the probability that the position corresponding to each grid is occupied by an obstacle;

[0075] Step 2: Based on the initial occupied grid map, obtain the target position corresponding to the target grid that is not occupied by the obstacle;

[0076] Step 3: Based on the initial occupied grid map, obtain the initial probability that occupied grids with a distance less than a predetermined distance from the target grid are occupied by obstacles. The occupied grid refers to a grid with an initial probability of being occupied by an obstacle greater than a predetermined probability.

[0077] Step 4: Control the mobile device equipped with the lidar to move to the target position, and acquire the echo signal of the laser emitted from the target position and arriving at the occupied position corresponding to the occupied grid;

[0078] Step 5: Determine the distance information between the mobile device and the target location based on the echo signal;

[0079] Step 6: Determine the occupancy probability based on the distance information, where the occupancy probability refers to the probability that the occupancy grid is occupied by an obstacle;

[0080] Step 7: When the occupancy probability is less than the initial probability and the change in probability is large (e.g., from 80% biased towards occupancy to 40% biased towards idle), it is determined that there is an invalid position on the path from the target position to the occupancy position, and the position corresponding to the grid that is simultaneously located on multiple paths is determined as the invalid position.

[0081] Step 8: Based on the invalid locations, construct an invalid point grid map, which is used to characterize the number of times and / or probability that the location corresponding to each grid is identified as an invalid location;

[0082] Step 9: Update the initial occupied grid map to obtain an updated occupied grid map, and update the invalid point grid map to obtain an updated invalid point grid map;

[0083] Step 10: Merge the updated occupied grid map and the updated invalid point grid map to obtain a merged grid map;

[0084] Step 11: Construct a laser SLAM map using the fused grid map, and / or perform navigation control;

[0085] Step 12: Based on the invalid locations, construct an invalid point grid map, which is used to characterize the number of times and / or probability that the location corresponding to each grid is identified as an invalid location.

[0086] Existing technologies for occupying grid maps specifically involve rasterizing the map, with each grid cell categorized as occupied, free, or unknown. The probability of the Free state is represented by p(s=1), and the probability of the Occupied state is represented by p(s=0), with their sum being 1. However, using only two values ​​to represent the state of a single grid cell is somewhat inappropriate; therefore, a ratio between the two values ​​is introduced to represent the grid cell's state: Once the lidar measurement result z arrives, the relevant grid needs to update its state. The updated grid state is as follows: We can obtain the following from Bayes' theorem. Therefore, a simple addition operation is used to update the state of the raster. Furthermore, the initial state S of a raster... init Since the default probability of a grid being empty or occupied is 0.5,

[0087] The above steps first identify the locations where the lidar cannot receive echoes as invalid locations, then construct an invalid point grid map based on these invalid locations, and use the invalid point grid map to represent the number of times and / or probability that the location corresponding to each grid is an invalid location. This solves the problem of insufficient accuracy in handling invalid locations of lidar in the existing technology.

[0088] This application presents two methods for constructing the invalid value raster map: The first method is used during the mapping process, i.e., when there is no complete occupied raster map yet, both the occupied raster map and the invalid value raster map are updated simultaneously. Each raster in the invalid value raster map records the number of times or probability information of being identified as an invalid value by the LiDAR. For each raster traversed by a ray corresponding to an invalid point in each frame of LiDAR, the probability of its invalid value is increased; for each raster traversed by a valid point in each frame of LiDAR, the probability of its invalid value is decreased. The update method for the probability values ​​is the same as the update method in the occupied raster map. Figure 3An occupancy grid map of an obstacle-free environment according to an embodiment of this application is shown; as follows: Figure 3 As shown; p(x=1) represents the probability of an invalid state, and p(x=0) represents the probability of an valid state. The grid state update formula is:

[0089] If a relatively complete occupied grid map already exists, then constructing an invalid value grid map is relatively simple. This is because we already know which points on the map are occupied and which are free. Figure 4 An occupancy grid map with obstacles is shown according to an embodiment of this application, such as... Figure 4 As shown, if we already know from the grid map that there is an obstacle at the hexagonal marker, and the laser radar emits rays (rays refer to...) at the diamond marker point... Figure 4 The arrow (indicated by the inner arrow) received an invalid value, which confirms the presence of a (reflective) obstacle within a grid cell between the lidar and the obstacle, because... Figure 3 and Figure 4 Similarly, therefore, we will not discuss this further here. Figure 3 To elaborate further.

[0090] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0091] 1) The lidar data processing method of this application obtains invalid locations, which are locations where the lidar cannot receive echoes; based on the invalid locations, an invalid point grid map is constructed. The invalid point grid map is used to characterize the number of times and / or probability that the location corresponding to each grid is identified as an invalid location. That is, the location where the lidar cannot receive echoes is first determined as an invalid location, and then an invalid point grid map is constructed based on the invalid locations. The invalid point grid map is used to represent the number of times and / or probability that the location corresponding to each grid is an invalid location, which solves the problem that the processing of invalid lidar locations in the prior art is not accurate enough.

[0092] 2) The lidar data processing apparatus of this application includes an acquisition unit and a construction unit. The acquisition unit is used to acquire invalid locations, which are locations where the lidar cannot receive echoes. The construction unit is used to construct an invalid point grid map based on the invalid locations. The invalid point grid map is used to characterize the number of times and / or the probability that the location corresponding to each grid is identified as an invalid location. That is, the location where the lidar cannot receive echoes is first determined as an invalid location, and then an invalid point grid map is constructed based on the invalid locations. The invalid point grid map is used to represent the number of times and / or the probability that the location corresponding to each grid is an invalid location, which solves the problem of insufficient accuracy in the processing of invalid lidar locations in the prior art.

[0093] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A lidar data processing method, characterized in that, include: Acquire invalid locations, where the lidar cannot receive echoes; Based on the invalid locations, an invalid point grid map is constructed, which is used to characterize the number of times and / or the probability that the location corresponding to each grid is identified as an invalid location; Obtaining the invalid location includes: Obtain an initial occupied grid map, which is used to characterize the probability that the position corresponding to each grid is occupied by an obstacle; Based on the initial occupied grid map, obtain the target position corresponding to the target grid that is not occupied by the obstacle; Based on the initial occupied grid map, the initial probability of occupied grids that are less than a predetermined distance from the target grid being occupied by obstacles is obtained. The occupied grid refers to a grid whose initial probability of being occupied by an obstacle is greater than a predetermined probability. Control the mobile device equipped with the lidar to move to the target position, and acquire the echo signal of the laser emitted from the target position and arriving at the occupied position corresponding to the occupied grid; The invalid location is determined based on the echo signal.

2. The method according to claim 1, characterized in that, Determining the invalid location based on the echo signal includes: The occupancy probability corresponding to the occupied grid is re-determined based on the echo signal. The occupancy probability refers to the probability that the occupied grid is occupied by an obstacle. If the occupancy probability is less than the initial probability, it is determined that there is an invalid location on the path from the target location to the occupied location.

3. The method according to claim 2, characterized in that, Based on the echo signal, the occupancy probability corresponding to the occupied grid is re-determined, including: The distance information between the mobile device and the target location is determined based on the echo signal; The occupancy probability is determined based on the distance information.

4. The method according to claim 2, characterized in that, If the occupancy probability is less than the initial probability, determining that an invalid location exists on the path from the target location to the occupied location includes: The positions corresponding to grids that are simultaneously located on multiple of the aforementioned paths are determined as invalid positions.

5. The method according to claim 1, characterized in that, The method further includes: The initial occupied grid map is updated to obtain an updated occupied grid map; The invalid point raster map is updated to obtain an updated invalid point raster map.

6. The method according to claim 5, characterized in that, After updating the invalid point raster map to obtain an updated invalid point raster map, the method further includes: The updated occupied grid map and the updated invalid point grid map are merged to obtain a merged grid map; The fused grid map is used to construct a laser SLAM map and / or for navigation control.

7. A lidar data processing device, characterized in that, include: An acquisition unit is used to acquire invalid locations, where the invalid location refers to a location where the lidar cannot receive an echo. A construction unit is used to construct an invalid point grid map based on the invalid locations, wherein the invalid point grid map is used to characterize the number of times and / or the probability that the location corresponding to each grid is identified as the invalid location; The acquisition unit includes: The first acquisition module is used to acquire an initial occupied grid map, which is used to characterize the probability that the position corresponding to each grid is occupied by an obstacle; The second acquisition module is used to acquire the target position corresponding to the target grid that is not occupied by the obstacle based on the initial occupied grid map; acquire the initial probability that the occupied grid that is less than a predetermined distance from the target grid is occupied by the obstacle based on the initial occupied grid map, wherein the occupied grid is a grid whose initial probability of being occupied by the obstacle is greater than the predetermined probability; control the mobile device equipped with the lidar to move to the target position, and acquire the echo signal of the laser emitted from the target position and reaching the occupied position corresponding to the occupied grid; and determine the invalid position based on the echo signal.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 6.

9. A processor, characterized in that, The processor is used to run a program, wherein the program executes the method according to any one of claims 1 to 6 when it runs.

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