A method for obtaining a laser beam analog line segment, a chip and a robot

Abstract

This invention discloses a method, chip, and robot for acquiring simulated laser beam segments. The method is applicable to mobile robots equipped with laser sensors. The method includes controlling the laser sensor to emit a laser beam that scans a target area to acquire a laser ranging segment; simultaneously acquiring a pre-constructed grid map; and acquiring simulated laser beam segments based on the number of obstacle grids traversed by the laser ranging segment within the allowable ranging error range. This simulated laser beam segment becomes a laser ranging segment capable of recognizing movement costs. It allows the simulated laser beam segment to serve as a simulated route for the mobile robot to traverse the obstacle grid, thus predicting the movement cost of the robot along a certain direction or specific route; thereby indirectly reflecting the smoothness of the simulated mobile robot's movement along the direction indicated by the laser ranging segment.

Description

Technical Field

[0001] This invention relates to the technical field of laser mapping algorithms, and in particular to a method, chip, and robot for obtaining simulated line segments using laser beams. Background Technology

[0002] Currently, when performing local accessibility analysis on grid maps, the accessibility of each grid is determined within a small, binary description. Then, grids with "accessible" accessibility are clustered globally. Finally, small fragments after clustering are filtered out and labeled as "unknown" or "impassable." The remaining "accessible" grids are labeled as "accessible." This approach only considers whether accessible areas are connected during the connectivity phase, ignoring the obstacle distribution in impassable areas, such as the degree of obstruction during movement in a specific direction. Therefore, existing technologies for analyzing local accessibility of grid maps cannot predict the cost of robot movement along a specific direction or route, resulting in low accuracy in identifying the accessibility of robots in specific directions or routes. Summary of the Invention

[0003] To overcome the aforementioned technical deficiencies, this invention discloses a method for obtaining simulated laser beam segments, used to obtain laser ranging segments with motion cost recognition capabilities from laser ranging segments mapped from the laser beam. The specific technical solution is as follows:

[0004] A method for acquiring simulated laser beam segments is disclosed. This method is applicable to mobile robots equipped with laser sensors. The method includes controlling the laser sensor to emit a laser beam to scan a region to be detected and acquiring laser ranging segments; simultaneously acquiring a pre-constructed grid map; and acquiring simulated laser beam segments based on the number of obstacle grids traversed by the laser ranging segments within the allowable range of ranging error, so that the simulated laser beam segments become laser ranging segments with motion cost recognition capabilities.

[0005] Furthermore, the source of the obstacle grid that the laser ranging line segment passes through within the allowable ranging error range is, within the grid map, along the straight line direction from the laser point to the observation point, setting a point at a preset error distance from the laser point as the target positioning point; wherein, the line connecting the observation point and the laser point is the laser ranging line segment; the observation point is the position marked by the laser sensor in the grid map; then, excluding the grid where the observation point is located and the grid where the target positioning point is located, the obstacle grid that the line connecting the observation point and the target positioning point passes through is marked as a pre-configured obstacle grid, and it is determined that the pre-configured obstacle grid is the obstacle grid that the laser ranging line segment passes through within the allowable ranging error range; wherein, the obstacle grid is the grid occupied by the obstacle in the area to be detected in the grid map.

[0006] Furthermore, when the observation point is located on the edge of the grid, the grid where the observation point is located is the first grid that the laser ranging line segment passes through along its laser observation direction; wherein, the laser observation direction is the straight line direction from the observation point to the laser point, forming the laser observation direction of the laser ranging line segment; when the target positioning point is located on the edge of the grid, the grid where the target positioning point is located is the first grid that the line connecting the target positioning point and the laser point passes through along the laser observation direction.

[0007] Further, the method for obtaining the simulated laser beam segment based on the number of obstacle grids traversed by the laser ranging line segment within the allowable range of ranging error includes, for the laser ranging line segment, counting the pre-configured obstacle grids traversed by the line connecting the observation point and the target positioning point; when it is determined that the count value of the pre-configured obstacle grids is greater than a preset threshold, setting the laser ranging line segment containing the line connecting the observation point and the target positioning point as the simulated laser beam segment; wherein, the count value of the pre-configured obstacle grids is used to represent the movement cost; wherein, one laser beam corresponds to one laser point, and one laser beam is converted into one laser ranging line segment in the grid map.

[0008] Furthermore, the acquisition method also includes: when the line connecting the observation point and the target positioning point does not pass through the obstacle grid, the laser ranging line segment where the target positioning point and the observation point are located is not set as the simulated line segment of the laser beam.

[0009] Furthermore, the acquisition method further includes: when the length of the line connecting the target positioning point and the laser point is greater than the length of the line connecting the observation point and the same laser point, the laser ranging line segment where the laser point and the observation point are located is not set as the simulated line segment of the laser beam.

[0010] Furthermore, when the length of the line connecting the observation point and the laser point is less than the preset threshold length, the preset error distance is a fixed value; when the length of the line connecting the observation point and the laser point is greater than or equal to the preset threshold length, the preset error distance is directly proportional to the length of the laser ranging line segment.

[0011] Furthermore, the laser point is located in the grid in the following ways: the laser point is located within the area enclosed by the four sides of the grid, and the laser point is located on the edge of the grid, so as to reflect the two-dimensional position information of the scanned object; wherein, within a frame of laser point cloud, the observation point is fixed, one target positioning point corresponds to one laser point, and one laser ranging line segment corresponds to one laser point.

[0012] Furthermore, the acquisition method further includes: controlling the laser information reflected by the laser beam in the area to be detected to be converted into laser points in the grid map, wherein the laser points are used to represent the location points of the scanned position points falling into the grid map; each time the laser beam rotates once in the area to be detected, the converted laser points are combined into a frame of laser point cloud; wherein one laser beam corresponds to one scanning angle, and one scanning angle corresponds to one laser point; wherein the observation point is the position marked by the laser sensor in the grid map, used to represent the emission starting point of the laser beam.

[0013] A chip that implements the acquisition method by executing internally stored algorithm program code.

[0014] A robot equipped with a laser sensor for emitting a laser beam to scan an area to be detected; the robot is also equipped with the aforementioned chip for controlling the robot to perform the aforementioned acquisition method.

[0015] Compared with existing technologies, this invention, based on the combination of a grid map and laser beams emitted by a laser sensor, obtains simulated laser beam segments by calculating the number of obstacle grids traversed by the laser ranging line segment within the allowable range of ranging error. This simulated laser beam segment becomes a laser ranging line segment with the function of recognizing movement costs, enabling it to serve as a simulated route for the mobile robot to traverse the obstacle grid, thus predicting the movement cost of the robot along a certain direction or a specific route. This indirectly reflects the smoothness of the simulated mobile robot's movement along the direction indicated by the laser ranging line segment. Furthermore, counting the simulated laser beam segments distributed in various directions can be used to determine the robot's behavior patterns. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for obtaining a simulated line segment of a laser beam, as disclosed in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a laser ranging line segment passing through an obstacle grid in a grid map, as disclosed in another embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of a laser ranging line segment passing through an obstacle grid in a grid map, as disclosed in another embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] This invention provides a method for acquiring simulated line segments using a laser beam, applicable to mobile robots, especially those operating in indoor environments, such as robotic vacuum cleaners, inspection robots, unmanned sampling robots, and unmanned forklifts. The mobile robot includes a robot body, sensors, a controller, and a locomotion mechanism. The robot body is the main structure of the robot and can be selected based on its actual needs, using appropriate shapes, structures, and materials (such as rigid plastics or metals like aluminum and iron). For example, it can be a relatively flat cylindrical shape commonly found in robotic vacuum cleaners. The locomotion mechanism, located on the robot body, provides the mobile robot with mobility. This locomotion mechanism can be implemented using any type of mobile device, such as rollers or tracks. Sensors are used to perceive the external environment and obtain depth information of the surrounding environment (e.g., a point cloud map of the robot's surroundings). Sensors can be any type of existing depth information acquisition equipment, including but not limited to laser sensors and RGBD cameras. One or more sensors can be used to achieve an omnidirectional detection range of 0 to 360 degrees.

[0021] Taking a cleaning robot as an example, a controller is installed inside the robot's body, and a drive wheel is installed on each of the left and right sides. A laser sensor, such as a lidar, is installed on the top of the robot's body as a navigation and positioning device. The controller is electrically connected to the drive wheels and the laser sensor. The main body of the cleaning robot includes a front section and a rear section, and has an approximately circular shape (both front and rear are circular). It can also have other shapes, including but not limited to an approximately D-shaped shape with a circular front and rear, or a rectangular or square shape with a circular front and rear.

[0022] In some embodiments, a collision sensor and a proximity sensor are disposed on the front part of the main body of the cleaning robot, a cliff sensor is disposed on the lower part of the main body of the cleaning robot, and a controller, a magnetometer, an accelerometer, a gyroscope, an odograph installed inside the drive wheels, and a drop sensor installed in the slots connecting the left and right drive wheels to the chassis of the robot are used to provide the controller with various position information and motion state information of the robot.

[0023] It should be noted that the environmental map constructed from laser point clouds needs to be divided according to a pre-defined grid size to obtain a grid map, which consists of multiple grids. For example, dividing the environmental map into 0.2*0.2m squares results in a 0.2*0.2m grid map. The controller is an electronic computing core built into the robot body, used to execute logical operations to achieve intelligent control of the robot. The controller is connected to the laser sensor and is used to execute a preset algorithm to construct a map image based on the depth information of the surrounding environment collected by the laser sensor. In the map image, obstacles typically have different pixel values ​​than other areas for easy differentiation.

[0024] This invention discloses a method for acquiring simulated line segments using a laser beam. This method is applicable to mobile robots equipped with laser sensors. In this embodiment, a laser sensor is fixedly mounted on the body of the mobile robot for omnidirectional detection from 0 to 360 degrees to acquire environmental information around the mobile robot. Figure 1 As shown, the acquisition method includes:

[0025] Step S101: Control the laser beam emitted by the laser sensor to scan the area to be detected, and acquire simulated line segments of the laser beam within the same area to be detected; simultaneously acquire a pre-built grid map, which may include the grid map of the area to be detected; then proceed to step S102. It should be noted that the laser head of the laser sensor detects its surrounding environment by rotating at a constant speed; the laser sensor uses a laser beam to scan the spatial range of the area to be detected at different angles, with each scanning angle corresponding to a laser point. The laser points from all scanning angles are combined to form a laser point cloud frame. One or more laser beams emitted by the laser sensor repeatedly scan the same area to be detected, and then the point clouds acquired by rotating all the laser beams once or by rotating one laser beam once are combined to form a laser point cloud frame. However, the pre-built grid map does not convert the real-time acquired laser points into the grid map, meaning that the pre-built grid map does not reflect the environmental information collected in real time by the mobile robot.

[0026] Step S102: Based on the number of obstacle grids passed by the laser ranging line segment within the allowable range of ranging error as described in step S101, obtain the simulated laser beam line segment so that the simulated laser beam line segment becomes a laser ranging line segment with the function of recognizing movement costs. Here, movement costs include collision costs. It can be assumed that the mobile robot collides with obstacles during its movement along the simulated laser beam line segment or the laser ranging line segment. After colliding with obstacles, a collision cost will be generated. Therefore, step S102 can be used to identify the movement cost.

[0027] In step S102, the number of obstacle grids actually traversed by the laser ranging line segment described in step S101 within the grid map is counted. This is understood as the frequency of each laser ranging line segment accessing the corresponding type of obstacle grid, rather than the frequency of accessing the same obstacle grid. This is to obtain the number of obstacle grids traversed by the laser ranging line segment within the allowable range of ranging error, thus indirectly obtaining the traversability of the route corresponding to the laser ranging line segment. The fewer the number of obstacle grids counted, the better the simulated traversal of the laser ranging line segment within the grid map. The better the drivability of the robot's movement path, the worse the drivability of the simulated route corresponding to the laser ranging segment, as the number of obstacle grids counted increases. This allows for the selection of laser beam simulation segments that effectively simulate the smoothness of the robot's movement along the direction indicated by the laser beam simulation segment. These laser beam simulation segments then become laser ranging segments with movement cost recognition capabilities, enabling the prediction of the robot's movement cost along a specific direction or route, thus improving the accuracy of drivability recognition for that specific direction or route. In summary, this allows for more effective adjustment of the map's real-time positioning information, providing a basis for the robot to plan new navigation paths and reach work areas with permissible drivability.

[0028] As one example, combined with Figure 2 and 3 It can be seen that the source of the obstacle grid that the laser ranging line segment passes through within the allowable range of ranging error is:

[0029] Within the grid map, along the straight line from the laser point to the observation point, a point that is a preset error distance away from the laser point is set as the target positioning point; wherein, the line connecting the observation point and the laser point is the laser ranging line segment; the observation point is the position marked by the laser sensor in the grid map. Figure 2 and Figure 3 The grid map shown has grids arranged in a regular manner, with each grid arranged in rows and columns. Point O is taken as the grid position occupied by the robot's laser sensor, i.e., the observation point. Figure 2Point N1 is a laser point. When the laser point is located within the area enclosed by the four sides of a grid, it means that the grid is the grid where the laser point is located. The line connecting point O and point N1 is the laser ranging line segment, forming the laser ranging line segment ON1.

[0030] In this embodiment, point M1 is set as the target positioning point on the laser ranging line segment ON1, wherein the length of line segment M1N1 is equal to the preset error distance; preferably, when the length ON1 of the line connecting the observation point O and the laser point N1 is less than the preset threshold length, the preset error distance is a fixed value; when the length ON1 of the line connecting the observation point O and the laser point N1 is greater than or equal to the preset threshold length, the preset error distance is directly proportional to the length of the laser ranging line segment; wherein the specific value of the preset threshold length varies depending on the specifications of the laser sensor actually used.

[0031] Then, excluding the grids where the observation point and the target positioning point are located, the obstacle grids traversed by the line connecting the observation point and the target positioning point are marked as pre-configured obstacle grids, and it is determined that the pre-configured obstacle grids are the obstacle grids traversed by the laser ranging line segment within the allowable range of ranging error; wherein, the obstacle grid is the grid occupied by the obstacle in the area to be detected in the grid map. Figure 2 In the grid map shown, on line segment OM1, except for the grid cell containing observation point O and the grid cell containing target positioning point M1, all grid cells traversed by line segment OM1 within the grid map are... Figure 3 The grid is identified by X. In this embodiment, the grid is binarized. When X=0 is detected, it means that the grid is a blank grid or an unknown grid. When X=1 is detected, it means that the grid is an obstacle grid, that is, the pre-configured obstacle grid. At this time, the obstacle grid through which the line connecting the observation point O and the target positioning point M1 passes is marked as the pre-configured obstacle grid.

[0032] As one embodiment, when the target positioning point is located on the edge of a grid, the grid where the target positioning point is located is the first grid that the line connecting the target positioning point and the laser point passes through along its laser observation direction; wherein, the laser observation direction is the straight line direction from the observation point to the laser point, forming the laser observation direction of the laser ranging line segment; in Figure 2In the grid map shown, point N2 is another laser point. Laser point N2 is located within the area enclosed by the four sides of a grid cell; this indicates that the grid cell containing laser point N2 is the grid cell containing laser point N2. The line connecting point O and point N2 forms a laser ranging line segment. In this embodiment, point M2 is set as the target positioning point on the laser ranging line segment ON2, where the length of line segment M2N2 is equal to the preset error distance. The laser observation direction of the laser ranging line segment ON2 is the straight line direction from observation point O to laser point N2, i.e., the direction indicated by the arrow on the laser ranging line segment ON2. Figure 2 As shown, the target positioning point M2 is located exactly on the edge of the grid. The grid where the target positioning point M2 is located is the first grid that line segment M2N2 passes through along the laser observation direction (the arrow of the laser ranging line segment ON2). Correspondingly, in Figure 2 In the map coordinate system shown, the coordinates of a grid are represented by the coordinates of its lower left corner. Therefore, the coordinates of the grid where laser point N2 is located are (1, 4), and the coordinates of the grid where the target positioning point M2 is located are also (1, 4). Thus, by searching along the laser observation direction or the laser ranging line segment, the grid where the laser point is located can be found within the surrounding area, closely approximating its actual physical location and improving the effectiveness of laser point positioning.

[0033] As one embodiment, when the observation point is located on the edge of a grid, the grid where the observation point is located is the first grid that the laser ranging line segment passes through along its laser observation direction; wherein, the laser observation direction is the straight line direction from the observation point to the laser point, forming the laser observation direction of the laser ranging line segment; in Figure 3 In the grid map shown, point N3 is a laser point and point O1 is an observation point. Laser point N3 is located within the area enclosed by the four sides of a grid, indicating that the grid is where laser point N3 is located. The line connecting point O1 and point N3 forms a laser ranging line segment. In this embodiment, point M3 is set as the target positioning point on the laser ranging line segment O1N3, where the length of line segment M3N3 is equal to the preset error distance. The laser observation direction of the laser ranging line segment O1N3 is the straight line direction from observation point O1 to laser point N3, i.e., the direction indicated by the arrow on the laser ranging line segment O1N3. The grid where observation point O1 is located is the first grid that the laser ranging line segment O1N3 passes through along its laser observation direction. Figure 3 When the observation point O1 is located on an edge directly below the grid with coordinates (1, 4), the grid where the observation point O1 is located can be the grid with coordinates (3, 1).

[0034] Specifically, if the column number of the raster is obtained as s0 and the row number of the raster is obtained as h0, then in Figure 2In the raster map shown, a neighboring raster is a raster whose row number ranges from [h0-1, h0+1] and column number ranges from [s0-1, s0+1], where s0 and h0 are integers. Figure 2 Within the grid map shown, Figure 2 The column number of the grid where the target location point M1 is located is 7. Figure 2 The row number of the grid where the target location point M1 is located is 3; in Figure 2 Within the grid map shown, Figure 2 The column number of the grid where laser point N1 is located is 7. Figure 2 The row number of the grid where the target location point N1 is located is 4; Figure 2 The column number of the raster where observation point O is located is 3. Figure 2 The row number of the raster where observation point O is located is 1; Figure 2 The column number of the grid where the target location point M2 is located is 1. Figure 2 The row number of the grid where the target location point M2 is located is 4; in Figure 2 Within the grid map shown, Figure 2 The column number of the grid where laser point N2 is located is 1. Figure 2 The row number of the grid where laser point N2 is located is 4. Figure 3 Within the grid map shown, Figure 3 The column number of the grid where the target location point M3 is located is 1. Figure 3 The row number of the grid where the target location point M3 is located is 4; in Figure 3 Within the grid map shown, Figure 3 The column number of the grid where laser point N3 is located is 1. Figure 3 The row number of the grid where laser point N3 is located is 4; Figure 3 The column number of the raster where observation point O1 is located is 3. Figure 3 The row number of the grid cell containing laser point O1 is 1. In the map coordinate system of the grid map disclosed in this embodiment, the coordinates of each grid cell are represented by the coordinates of its lower left corner point. The coordinates of the lower left corner point of the grid cell are used to represent the row and column numbers of the grid cell in the grid map, with the horizontal coordinate equal to the column number and the vertical coordinate equal to the row number. For example... Figure 3 and Figure 2 As shown in the raster map, the raster is traversed from left to right, with the column number increasing sequentially; the raster is traversed from bottom to top, with the row number increasing sequentially. This ensures that the paths generated by connecting each raster within the raster map are continuous. For ease of understanding, in Figure 3 and Figure 2 In the map coordinate system shown, the coordinates of a grid are represented by the coordinates of its lower left corner.

[0035] As one embodiment, the method for obtaining the simulated laser beam segment based on the number of obstacle grids traversed by the laser ranging line segment within the allowable range of ranging error includes:

[0036] In the laser ranging line segment, along the line connecting the observation point and the target positioning point, the number of pre-configured obstacle grids traversed by the line is counted; correspondingly, for Figure 2 In the line segment OM1 shown, except for the grid cells at the two endpoints, the obstacle grid cells traversed by the remaining portion are counted. This can be done by counting each obstacle grid cell one by one along the direction from the observation point O to the target positioning point M1, obtaining the number of pre-configured obstacle grid cells on the laser ranging line segment ON1, or obtaining the count value of the pre-configured obstacle grid cells on the line segment OM1. The line connecting the observation point O and the target positioning point M1 lies on the laser ranging line segment ON1. Simultaneously, for... Figure 2 In the line segment OM2 shown, except for the grids where the two endpoints are located, the obstacle grids that the rest of the line segment passes through are counted. This can be done by counting each obstacle grid one by one along the direction from the observation point O to the target positioning point M2, to obtain the number of pre-configured obstacle grids on the laser ranging line segment ON2, or by obtaining the count value of the pre-configured obstacle grids on the line segment OM2. The line connecting the observation point O and the target positioning point M2 is located on the laser ranging line segment ON2.

[0037] For a laser ranging line segment, when it is determined that the count value of the pre-configured obstacle grid is greater than a preset number threshold, the laser ranging line segment where the line connecting the observation point and the target positioning point is located is set as the simulated laser beam line segment. Then, a laser ranging line segment with motion cost recognition function is obtained in the laser point cloud frame. Subsequently, a laser beam corresponding to the straight line direction from the observation point to the target positioning point is marked as a laser beam with motion cost recognition function. The count value of the pre-configured obstacle grid is used to represent the motion cost.

[0038] In an embodiment corresponding to a frame of laser point cloud, whenever the count value of the pre-configured obstacle grid is determined to be greater than a preset threshold along a laser ranging line segment, the laser ranging line segment connecting the observation point and the target positioning point is set as a laser ranging line segment with motion cost recognition function, thereby obtaining a simulated laser beam line segment as a newly determined laser ranging line segment or laser beam with motion cost recognition function within the frame of laser point cloud. This allows the extraction of laser ranging lines that have traversed a sufficient number of obstacles, which can represent the number of obstacles detected by the mobile robot during its movement along the line connecting the observation point and the target positioning point. This simulates the collision situation between the mobile robot and obstacles during its movement along the laser ranging line segment, as well as the number and distribution characteristics of obstacles in the corresponding laser observation direction, characterizing the passability of the environment on both sides of the laser ranging line segment. Therefore, the simulated laser beam line segment can serve as a simulated route for the mobile robot to traverse the obstacle grid.

[0039] It should be noted that the preset quantity threshold is an experimental result obtained by the mobile robot using real-time collected laser point clouds to construct a grid map. It is a threshold for the number of obstacles in a specific direction obtained through repeated experiments in the area to be detected, in order to distinguish the grid map information constructed by laser point clouds collected on a flat travel plane.

[0040] Preferably, the acquisition method further includes: when the line connecting the observation point and the target positioning point does not pass through an obstacle grid, the laser ranging line segment where the target positioning point and the observation point are located is not set as the laser beam simulation line segment, that is, the laser ranging line segment with motion cost recognition function. In this case, the increment of the number of the currently acquired laser beam simulation line segments in the laser point cloud frame is 0. Figure 2 It can be seen that if the line connecting the observation point O and a currently obtained target positioning point M1 does not pass through the obstacle grid, then the laser ranging line segment ON1 where the currently obtained target positioning point M1 and the observation point O are located will not be set as the laser beam simulation line segment. Therefore, among the lines connecting the same observation point O and multiple target positioning points (corresponding to multiple laser beams or multiple laser beam simulation line segments), lines that do not cross obstacles are directly excluded because they belong to laser ranging lines in open areas, thus their ability to identify movement costs is weak, and they lack the ability to identify the distribution characteristics of specific obstacles; therefore, they are not set as the laser beam simulation line segment.

[0041] Preferably, the acquisition method further includes: when the line length connecting the target positioning point and its corresponding laser point is greater than the line length connecting the observation point and the same laser point, the laser ranging line segment where the target positioning point is located is not set as the laser beam simulation line segment, then within the laser point cloud of a frame, the increment of the number of currently acquired laser beam simulation line segments is 0. Figure 2 Based on this, it can be deduced that if the length of the line connecting the target positioning point M2 and its corresponding laser point N2 is greater than the length of the line connecting the observation point O and the laser point N2, that is, when the length of line segment M2N2 is greater than the length of line segment ON2, it indicates that the ranging error of the laser ranging line segment ON2 formed by the laser sensor is large. Therefore, the laser ranging line segment ON2 is not set as the simulated line segment of the laser beam. This means that the laser ranging line segment ON2 cannot be configured as a laser ranging line segment with motion cost recognition function due to the sensor ranging error it carries.

[0042] In the foregoing embodiments, the laser point is located in the grid in two ways: the laser point is located within the area enclosed by the four sides of the grid, and the laser point is located on the edge of the grid, so as to reflect the two-dimensional position information of the scanned object, that is, the position of the feature point reflected from the surface of the scanned object is converted into coordinate information in the grid map; optionally, in a frame of laser point cloud, the observation point is fixed, indicating that the laser sensor is fixed in a specific position; one target positioning point corresponds to one laser point, one laser beam corresponds to one laser point, one laser beam simulates a line segment corresponds to one laser point, and one laser beam corresponds to one laser beam simulates a line segment, so that each laser beam can reflect the corresponding positioning information in the grid map and is represented by a specific laser point.

[0043] In the above embodiments, after the laser sensor (i.e., single-line lidar or multi-line lidar) emits one or more laser beams, each laser beam rotates once following the laser probe of the laser sensor. The laser information reflected by the laser beam within the area to be detected is converted into laser points in the grid map. These laser points represent the location points of the scanned positions within the grid map. Each time the laser beam rotates once within the area to be detected, i.e., one or more laser beams scan and cover the area once, the converted laser points form a laser point cloud frame. One laser beam corresponds to one laser point, one scanning angle corresponds to one laser point, and all laser points corresponding to all scanning angles form a laser point cloud frame.

[0044] For a fixed object being scanned, a laser sensor can be moved to acquire as much surface point information as possible. When a laser beam illuminates the surface of the object, the reflected laser information carries information such as orientation and distance. Combining laser measurement and photogrammetry principles, a point cloud is obtained, including coordinates (XY), laser reflection intensity, and color information (RGB). Specifically, after acquiring the spatial coordinates of each sampling point on the surface of the scanned object, the laser sensor obtains a set of points, called a point cloud, which is also a massive collection of points representing the surface characteristics of the target. When the 3D data obtained from different observation points (understood as laser sensors located at different positions or laser sensors moved sequentially to different positions) have a certain overlap and can completely cover the scanned object, it indicates that sufficient 3D point cloud data of the surface has been obtained. The point clouds obtained from different observation points are all uniformly transformed into a map coordinate system.

[0045] It should be noted that a laser point is a coordinate point on a grid map converted from the laser information reflected from the scanned object collected by a laser sensor. A laser point is a laser scanning point or laser sampling point, reflecting positional information (including the detection distance and angle to the surface of the scanned object) and laser reflection intensity. Specifically, if a laser sensor scans the object with a laser beam along a certain trajectory, it will record the reflected laser point information while scanning. Due to the extremely fine scanning, a large number of laser points can be obtained, thus forming a laser point cloud. The laser sensor is generally a lidar that supports 360-degree rotation scanning, equipped with a laser emitting probe and a receiving probe. Specifically, the laser information reflected from the scanned object collected by the laser sensor includes a lidar data packet, which contains several frames of laser point cloud data. Each frame of laser point cloud data includes several laser points, and each laser point contains an angle (counter-clockwise is the positive direction) and a distance.

[0046] In the grid map, the line connecting an observation point and a laser point is set as the laser ranging line segment. This determines that the laser beam is mapped to the laser ranging line segment in the grid map, so that one laser ranging line segment corresponds to one laser point, and thus one laser beam simulates a line segment corresponding to one laser point. The observation point is the position marked by the laser sensor in the grid map, which is used to indicate the starting point of the laser beam emission. It can be marked as the current position or the starting point position of the search of the mobile robot.

[0047] In some embodiments, when a frame of laser point cloud is acquired, those skilled in the art can easily obtain the position and angle of each laser point in the frame of laser point cloud in the lidar coordinate system, as well as the environmental intensity information it carries. The lidar is fixed on the mobile robot. In some embodiments, two frames of laser point clouds correspond to the same entity in physical space. The reason why the two frames of laser point clouds appear different is that the lidar moves with the mobile robot, so laser point cloud A corresponds to the robot's pose in the previous frame, and laser point cloud B corresponds to the robot's pose in the current frame; by aligning the two frames of laser point clouds, the relative pose relationship between the two frames can be calculated.

[0048] The present invention also discloses a chip that executes internally stored algorithm program code to implement any step of the laser beam simulated line segment acquisition method disclosed in the foregoing related embodiments.

[0049] The present invention also discloses a robot equipped with a laser sensor for emitting a laser beam to scan an area to be detected; the robot is equipped with the aforementioned chip for controlling the robot to perform the aforementioned acquisition method.

[0050] When the aforementioned robot is a cleaning robot, the cleaning robot can be equipped with this chip to detect the obstacles that the laser ranging line segment or the laser beam simulated line segment passes through, so as to determine the passability in the corresponding direction. For example, it can be used to detect whether there are steps, cliffs or slopes in front of the traveling plane of the mobile robot.

[0051] Specifically, after acquiring the simulated line segment of the laser beam, the cleaning robot can make the simulated line segment of the laser beam a simulated route for the mobile robot to traverse the obstacle grid, which can predict the movement cost of the robot along a certain direction or a specific route; the chip is set on the circuit board inside the cleaning robot, including a computing processor, such as a central processing unit or application processor, which communicates with non-temporary memory, such as hard disk, flash memory, random access memory, etc. The application processor executes a mapping algorithm, such as Simultaneous Localization and Mapping (SLAM), based on the obstacle information fed back by the laser sensor, to draw a real-time map of the robot's environment and mark the location of obstacles. In some embodiments, the robot's current working state, location, and posture are determined by combining distance and speed information fed back from sensors such as laser sensors, cliff sensors, drop sensors (a type of limit switch triggering device), magnetometers, accelerometers, gyroscopes, and odometers mounted on the buffer. Examples include crossing a threshold, stepping onto a carpet, being on a step or cliff, having a full dustbin, or being lifted. Specific next action strategies are then provided for different situations, making the robot's work more in line with the owner's requirements and providing a better user experience.

[0052] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for obtaining a simulated line segment using a laser beam, applicable to a mobile robot equipped with a laser sensor, characterized in that, The acquisition method includes: The laser beam emitted by the laser sensor is controlled to scan the area to be detected and obtain the laser ranging line segment; at the same time, a pre-constructed grid map is acquired. Based on the number of obstacle grids that the laser ranging line segment passes through within the allowable range of ranging error, a simulated laser beam line segment is obtained, so that the simulated laser beam line segment becomes a laser ranging line segment with the function of recognizing movement cost. The source of the obstacle grid that the laser ranging line segment passes through within the allowable ranging error range is: Within the grid map, along the straight line from the laser point to the observation point, a point at a preset error distance from the laser point is set as the target positioning point; wherein, the line connecting the observation point and the laser point is the laser ranging line segment; the observation point is the position marked by the laser sensor in the grid map; Then, excluding the grid where the observation point is located and the grid where the target positioning point is located, the obstacle grids through which the line connecting the observation point and the target positioning point passes are marked as pre-configured obstacle grids, and it is determined that the pre-configured obstacle grids are the obstacle grids through which the laser ranging line segment passes within the allowable range of ranging error; wherein, the obstacle grid is the grid in the grid map corresponding to the obstacle in the area to be detected; The method for obtaining the simulated laser beam segment based on the number of obstacle grids traversed by the laser ranging line segment within the allowable range of ranging error includes: For the laser ranging line segment, along the line connecting the observation point and the target positioning point, the number of pre-configured obstacle grids that the line passes through is counted. When it is determined that the count value of the pre-configured obstacle grids is greater than a preset number threshold, the laser ranging line segment where the line connecting the observation point and the target positioning point is located is set as the laser beam simulation line segment. The count value of the pre-configured obstacle grid is used to represent the movement cost; In this system, one laser beam corresponds to one laser point, and one laser beam is converted into a laser ranging line segment in the grid map.

2. The acquisition method according to claim 1, characterized in that, When the observation point is located on the edge of the grid, the grid where the observation point is located is the first grid that the laser ranging line segment passes through along its laser observation direction; wherein, the laser observation direction is the straight line direction from the observation point to the laser point, so as to form the laser observation direction of the laser ranging line segment; When the target positioning point is located on the edge of the grid, the grid in which the target positioning point is located is the first grid that the line connecting the target positioning point and the laser point passes through along the laser observation direction.

3. The acquisition method according to claim 1, characterized in that, The acquisition method further includes: when the line connecting the observation point and the target positioning point does not pass through the obstacle grid, the laser ranging line segment where the target positioning point and the observation point are located is not set as the simulated line segment of the laser beam.

4. The acquisition method according to claim 1, characterized in that, The acquisition method further includes: when the length of the line connecting the target positioning point and the laser point is greater than the length of the line connecting the observation point and the same laser point, the laser ranging line segment where the laser point and the observation point are located is not set as the laser beam simulation line segment.

5. The acquisition method according to claim 1, characterized in that, When the length of the line connecting the observation point and the laser point is less than the preset threshold length, the preset error distance is a fixed value; When the length of the line connecting the observation point and the laser point is greater than or equal to the preset threshold length, the preset error distance is directly proportional to the length of the laser ranging line segment.

6. The method for obtaining according to any one of claims 2 to 5, characterized in that, The laser point is positioned in the grid in two ways: the laser point is located within the area enclosed by the four sides of the grid, and the laser point is located on the edge of the grid, so as to reflect the two-dimensional position information of the scanned object. Within a single frame of laser point cloud, the observation points are fixed; one target positioning point corresponds to one laser point, and one laser ranging line segment corresponds to one laser point.

7. The method for obtaining according to any one of claims 1 to 5, characterized in that, The acquisition method further includes: The laser information reflected by the laser beam in the area to be detected is converted into laser points in the grid map, wherein the laser points are used to represent the location points of the scanned position points falling into the grid map; each time the laser beam rotates once in the area to be detected, the converted laser points are combined into a frame of laser point cloud; wherein one laser beam corresponds to one scanning angle, and one scanning angle corresponds to one laser point. The observation point is the location marked by the laser sensor in the grid map, which indicates the starting point of the laser beam emission.

8. A chip, characterized in that, The chip implements the acquisition method according to any one of claims 1 to 7 by executing the algorithm program code stored internally.

9. A robot equipped with a laser sensor for emitting a laser beam to scan an area to be detected; characterized in that, The robot is equipped with the chip of claim 8, which is used to control the robot to perform the acquisition method of any one of claims 1 to 7.

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