Robot map exploration method based on reachable boundary points, and chip

Abstract

A robot map exploration method based on reachable boundary points, and a chip. The method comprises: step A, a robot fitting a preset boundary line by using boundary points in the current detection area thereof, and selecting, in a map to be optimized, a contour line used for defining all connected detectable areas as a target contour line; step B, respectively controlling both ends of the preset boundary line to extend to obtain a preset boundary extension line segment; when the extension length on both ends of the preset boundary line is either shorter than or equal to a preset sensing radius, if both ends of the preset boundary extension line segment intersect with the target contour line, then executing step C; step C, on the basis of the preset boundary extension line segment, and in the direction in communication with the unknown region, segmenting from the target contour line a contour line to be followed, and then the robot searching for front-edge boundary points in the area surrounded by the contour line to be followed and the preset boundary extension line segment; step D, selecting reachable boundary points according to the reachability of the front-edge boundary points found in step C.

Description

Robot map exploration method based on reachable boundary points and chip TECHNICAL FIELD

[0001] The present application relates to the technical field of robot map exploration, and relates to a robot map exploration method based on reachable boundary points and a chip. BACKGROUND

[0002] Robots actively explore unknown environments and construct environment maps, which are of great significance for mobile robots to achieve autonomous navigation. Many mobile robot-related technologies are centered around maps.

[0003] Before cleaning, a cleaning robot needs to quickly construct a complete environment map of a house. Typically, a cleaning robot identifies unknown areas, navigates to the unknown areas, and expands the environment map using a laser radar to scan. However, the mapping of the cleaning robot is gradually built during walking. Such a mapping method of the cleaning robot is not suitable for scenarios where the cleaning robot needs to quickly obtain a map of an unknown area, affecting the navigation efficiency of the cleaning robot.

[0004] The Chinese invention patent with patent application number CN202110264567.X obtains boundary points meeting preset traffic conditions based on a boundary detector of a fast exploration random tree algorithm, and selects the boundary point with the highest profit from the boundary points stored in a boundary point list based on the navigation cost of the boundary points and the corresponding benefit information and considering the passable condition of the boundary points, and configures the boundary point as a target point. The robot is controlled to move from the current position to the target point to guide the robot to establish a map in the unknown area. Therefore, the method for constructing a map using boundary points in the unknown area of the Chinese invention patent mainly considers factors such as the exploration repeatability of the boundary points, the information gain of the boundary points, and the navigation cost, and then selects the best boundary point in the current field of view as the target point through a complex benefit calculation function. However, the overall time consumption is relatively long, which affects the exploration efficiency. The influence of the contour line in the local map on the mapping of the cleaning robot is also not considered. SUMMARY

[0005] The present application discloses a robot map exploration method based on reachable boundary points, and the specific technical solutions are as follows:

[0006] The robot map exploration method based on reachable boundary points comprises: a robot acquires a laser point cloud by scanning through a laser sensor, and constructs a to-be-optimized map by using the laser point cloud; the robot map exploration method further comprises: step A, the robot fits a preset boundary line by using boundary points in a current detection area of the robot, selects a contour line for delimiting all connected detectable areas in the to-be-optimized map as a target contour line, and then executes step B; step B, two ends of the preset boundary line are respectively controlled to expand, and a preset boundary expansion line segment is obtained; in the case that the expansion lengths of the two ends of the preset boundary line are both less than or equal to a preset perception radius, if the two ends of the preset boundary expansion line segment both intersect with the target contour line, step C is executed; step C, based on the preset boundary expansion line segment, the robot divides a to-be-tracked contour line from the target contour line in a direction connected with an unknown area, and then the robot searches for front boundary points in an area surrounded by the to-be-tracked contour line and the preset boundary expansion line segment; then step D is executed; step D, according to the passability of the front boundary points searched out in step C, reachable boundary points are screened out and the reachable boundary points are sequentially saved, so that the directions in which lines connecting respective reachable boundary points visited by the robot in sequence extend simulate the direction in which the robot walks along the target contour line.

[0007] The application also discloses a chip for storing program code for executing the robot map exploration method.

[0008] Compared with the prior art, the application firstly fits a preset boundary line by using detected boundary points, and determines the intersection of the preset boundary line after expansion with a target contour line by expanding the preset boundary line, so as to divide a to-be-tracked contour line from the target contour line, then searches for front boundary points only in a region range involved by the to-be-tracked contour line, and subsequently assigns the front boundary points to the robot in sequence for navigation and mapping after passability inspection, thereby being applicable to a scenario in which the robot needs to quickly explore a map of an unknown region, optimizing a mapping process and achieving the effect of fast mapping. Since the to-be-tracked contour line is obtained by dividing the target contour line by using the result of expansion of the preset boundary line, the robot only selects reachable boundary points in a region range corresponding to the to-be-tracked contour line, so that the robot not only reduces search quantity and calculation quantity, but also can navigate and map in the unknown region according to a certain distance span, overcomes the problem that in the process of robot mapping / exploring a map, distances between adjacent two navigation points are increasingly short and mapping similarity is high, and improves the efficiency of robot exploration of a map. BRIEF DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a schematic diagram of a robot adopting a laser sensor to scan a surrounding environment and construct a map in a process of gradually walking close to a long corridor according to the prior art. Wherein:

[0010] Fig. 1(a) shows that the robot detects two frontier points (white circles crossed by line segments R11A1 and R11B1 respectively) at position R11, the left side of the robot's field of view A1R11B1 is connected to known areas of each rectangular room region and part of the corridor, and the right side of the robot's field of view A1R11B1 is connected to unknown areas of each rectangular room region and part of the corridor.

[0011] Fig. 1(b) shows that the robot detects two frontier points (white circles crossed by line segments R12A2 and R12B2 respectively) at position R12, the left side of the robot's field of view A2R12B2 is connected to known areas of each rectangular room region and part of the corridor, and the right side of the robot's field of view A2R12B2 is connected to unknown areas of each rectangular room region and part of the corridor; wherein position R12 is closer to the wall where line segment B2P is located in the vertical direction than position R11, and the wall where line segment B2P is located and the wall where line segment B1P in Fig. 1(a) is located are the same side wall of the long corridor.

[0012] Fig. 1(c) shows that the robot detects two frontier points (white circles crossed by line segments R13A3 and R13B3 respectively) at position R13, the left side of the robot's field of view A3R13B3 is connected to known areas of each rectangular room region and part of the corridor, and the right side of the robot's field of view A2R12B2 is connected to unknown areas of each rectangular room region and part of the corridor; wherein position R13 is closer to the wall where line segment B3P is located in the vertical direction than position R12, and the wall where line segment B3P is located and the wall where line segment B2P in Fig. 1(b) is located are the same side wall of the long corridor.

[0013] Fig. 2 is a schematic diagram of the robot repairing the currently detected unknown areas to known areas in the process of walking in the long corridor according to another embodiment of the present application. Wherein:

[0014] Fig. 2(a) shows that the robot detects frontier point F11 and frontier point F12 at position R21, the left side (also referred to as the outer side) of the robot's field of view A11R21B11 is connected to known areas of each rectangular room region (separated by the corresponding skeleton) and part of the corridor, and the right side (also referred to as the inner side) of the robot's field of view A11R21B11 is connected to unknown areas of each rectangular room region and part of the corridor, at this time the robot has not started to perform the map repairing operation on triangular region A11R21B11.

[0015] Fig. 2(b) shows that the robot detects the frontier point F13 at position R21 and has started to perform a map repair operation for the triangular area A11R21B11, at this time, the robot marks the current explored area R21A11B11 as a known area R21A11B11, and the connected areas of each rectangular room and part of the corridor on the right side of the line segment A11B11 are unknown areas to reduce the unknown areas relative to the unknown areas in Fig. 2(a).

[0016] Fig. 3 is a schematic diagram showing the robot performing a map repair operation and exploring a larger range of unknown areas during the process of walking in a long corridor according to another embodiment of the present application. In which:

[0017] Fig. 3(a) shows that the robot detects the reachable frontier point F13 at position R21 and marks the current explored area R21A11B11 as a known area after performing a map repair operation, at this time, the connected areas of each rectangular room and part of the corridor on the left side of the line segment A11B11 are known areas, and the connected areas of each rectangular room and part of the corridor on the right side of the line segment A11B11 are unknown areas.

[0018] Fig. 3(b) shows that the robot walks to position R22 (corresponding to the position of the reachable frontier point F13 in Fig. 3(a)) to detect the reachable frontier point F14 and marks the current explored area R22A12B12 as a known area after performing a map repair operation, at this time, the connected areas of each rectangular room and part of the corridor on the left side of the line segment A12B12 are known areas, and the connected areas of each rectangular room and part of the corridor on the right side of the line segment A12B12 are unknown areas to reduce the unknown areas relative to the unknown areas in Fig. 3(a).

[0019] Fig. 3(c) shows that the robot walks to position R23 (corresponding to the position of the reachable frontier point F14 in Fig. 3(b)) to detect the reachable frontier points F15, F16, F17 and F18 in sequence in a clockwise direction, and marks the current explored area R23IHU, the area R23QOST and the connected areas of each rectangular room and the entire corridor area on the left side of the detection angle CR23P as known areas, wherein the line segment CU passes through the reachable frontier point F15 and becomes the boundary line between the known area R23IHU and the unknown area EGUCD, the line segment IT passes through the reachable frontier point F16 and becomes the boundary line between the known area R23QOST and the unknown area ITH, the line segment PQ passes through the reachable frontier point F18 and becomes the boundary line between the known area R23QOST and the unknown area MPQ, and the boundary lines formed by the line segment QO and the line segment OS in sequence become the boundary lines between the known area R23QOST and the connected unknown areas below it.

[0020] Fig. 4 is a diagram illustrating a tree structure for storing the detected reachable boundary points by the robot according to another embodiment of the present application, wherein the reachable boundary points F15, F16, F17 and F18 are nodes at the same depth, and the order of visiting them in the clockwise direction in Fig. 3(c) is F15, F16, F17 and F18, respectively, and the starting point of visiting the unknown region under the known region R23QOST is the reachable boundary point F17, and the starting point of the robot to detect a new reachable boundary point in the unknown region under the known region R23QOST is the reachable boundary point F17.

[0021] Fig. 5 is a flowchart illustrating a method for robot map exploration based on reachable boundary points according to an embodiment of the present application.

[0022] Fig. 6 is a flowchart illustrating a method for extending both ends of a preset boundary according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The specific embodiments of the present application will be further described with reference to the drawings. The accompanying drawings are part of the disclosure and serve to illustrate the embodiments. They mainly serve to illustrate the embodiments and can be used to explain the operating principle of the embodiments in conjunction with the relevant description of the specification. Those of ordinary skill in the art should be able to understand other possible embodiments and advantages of the present application in conjunction with these contents. As a process or method depicted by a flowchart. Although the flowchart describes each step as a sequential process, many of the steps can be implemented in parallel, concurrently or simultaneously. In addition, the order of the steps can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc. It should be noted that when a search algorithm is used to solve a problem, a data structure that indicates the state characteristics and the relationship between different states needs to be constructed. Such a data structure is called a node. Different problems require different data structures to describe. According to the given conditions of the search problem, one or more new nodes can be generated from a node. This process is usually called expansion.

[0024] It should be noted that when the robot moves on the ground of the unknown room environment to complete the related navigation work, the robot needs to search for a suitable navigation target point in the unknown room environment before moving, so as to execute the planned cleaning and navigation along the planned path. Generally, the indoor environment is divided into multiple rooms by walls, and furniture and other obstacles are placed on the ground. In order to facilitate the distinction, the furniture and other obstacles are represented as closed boxes, and the room area is represented as the area in three of the four directions that is blocked by the obstacles. As can be easily understood, the walls, furniture and other objects that can block the movement of the robot can be regarded as obstacles. The contour points in the wall of the room area or the corridor can be understood as boundary points, the points on the boundary line between different room areas can be understood as boundary points, and the points on the boundary line between the room area and the corridor passage can also be understood as boundary points.

[0025] The indoor environment where the robot is located is divided into multiple rooms and long corridors connected between the rooms by walls, as shown in the house layout diagrams in FIGS. 1 to 3.

[0026] The mapping situation of the robot during walking in the long corridor is shown in FIG. 1. In FIG. 1(a), the robot detects two front boundary points (white circles through line segments R11A1 and R11B1, respectively) at position R11. The connected rectangular room areas and corridor areas on the left side of the detection angle A1R11B1 of the laser sensor in the robot are all areas that have been traversed by the robot. The area on the right side of the detection angle A1R11B1 of the laser sensor in the corridor area is an unknown area that needs to be explored by the robot.

[0027] Then the robot walks to position R12 in FIG. 1(b) and detects two front boundary points (white circles through line segments R12A2 and R12B2, respectively). The right side of the detection angle A2R12B2 of the laser sensor in the corridor area is an unknown area that needs to be explored by the robot at position R12. The position R12 is closer to the wall where line segment B2P is located in the vertical direction than the position R11 (the wall where line segment B2P is located and the wall where line segment B1P in FIG. 1(a) is located are the same side wall of the long corridor). The detection angle of the laser sensor in the corridor area does not change much, that is, the detection range of the robot does not change much during the movement of the robot in the corridor area from position R11 to position R12. The horizontal distance between position R11 and position R12 is less than or equal to the horizontal distance from the front boundary point detected by the robot at position R11 to position R11.

[0028] Then the robot walks to the position R13 in Fig. 1(c), detects two front boundary points (white circles passed by line segments R13A3 and R13B3 respectively), the area required to be detected by the laser sensor of the robot on the right side of the detection angle A2R12B2 of the corridor area does not change too much relative to the unknown area required to be explored by the robot at the position R12, wherein the horizontal distance between the position R13 and the position R12 is less than or equal to the horizontal distance from the nearest front boundary point detected by the robot at the position R12 to the position R12. The position R13 is more close to the wall where the line segment B3P is located in the vertical direction relative to the position R12, and the wall where the line segment B3P is located and the wall where the line segment B2P in Fig. 1(b) is located are the same side wall of the long corridor.

[0029] In summary, the robot represented by the black circle in Fig. 1 performs edge detection in the constructed laser map, and the obtained front boundary points appear on the left and right sides of the fan-shaped area formed by the detection angle of the laser sensor in the corridor area, and the front boundary points are the boundary points in the boundary line between the unknown area and the known area, which are represented by white circles in Fig. 1. In order to gradually construct a complete laser map, the robot walks closer and closer to the wall of the long corridor during the process of walking in the long corridor, and the positional relationship between the robot, its detection range and the detected front boundary points changes from left to right in Fig. 1(a), (b) and (c). As can be seen from Fig. 1(a), (b) and (c), the distance between the black circle and the wall of the long corridor on one side to which the black circle is close decreases, and the distance between the white circle detected by the black circle in the direction of the wall to which the black circle is close also decreases. Therefore, the robot is closer and closer to the wall on one side of the long corridor in the environment of Fig. 1(a), (b) and (c), and the distance between the detected front boundary points and the robot becomes shorter and shorter, that is, the robot appears more and more close to the wall during the rapid mapping process, and the distance between the mapping navigation points becomes shorter and shorter, which leads to that the cleaning robot constructs fewer new maps during the walking process in the corridor area, and the mapping process becomes slow.

[0030] In view of the foregoing technical defects, the present application discloses a robot map exploration method based on reachable boundary points, which comprises:

[0031] The robot obtains laser point cloud by scanning with a laser sensor, and then constructs a to-be-optimized map using the laser point cloud. Specifically, before performing cleaning work, the robot needs to quickly construct a complete environmental map of the house, i.e. the to-be-optimized map in the present application, because the present application identifies front boundary points in the unknown area at the pre-set front boundary points, navigates to the front boundary points in the unknown area, and continuously expands the environmental map by scanning with the laser sensor.

[0032] The laser sensor is preferably a laser radar, the scanning distance is 0.1-3.5 meters, the scanning range is 360 degrees, and the scanning range in the area in front of the robot is less than 360 degrees due to the wall blocking of the corridor area. A two-dimensional grid map is established by using the laser point cloud as the to-be-optimized map, and the environment is divided into three types, known area and unknown area, preferably, the grid value of the known and passable area is 0, the grid value of the known and obstacle area is 100, and the grid value of the unknown area is -1. Initially, the entire map is a blank map area or an unknown map area, after exploration by the laser sensor, the corresponding grid value of the map changes, and the map is updated.

[0033] As shown in FIG. 5, the robot map exploration method comprises:

[0034] Step A, the robot fits a preset boundary line using the boundary points in its current detection area, and selects a contour line for delineating all connected detectable areas in the to-be-optimized map as a target contour line, forming the largest contour that can be detected in the to-be-optimized map, and the target contour line can delineate known areas and unknown areas. The robot can fit preset boundary lines in different directions using the boundary points in its current detection area, so that there are multiple preset boundary lines to be extended in step B, and there are also multiple preset extension boundary lines for subsequent intersection judgment with the target contour line.

[0035] All connected detectable areas exist in the current detection area; in some embodiments, the outer contour of the indoor environment where the robot is located can be set as the exploration boundary of the robot to prevent the robot from exploring outdoor areas and ensure accurate acquisition and improvement of the to-be-optimized map. Then step B is performed.

[0036] The current detection area of the robot can be regarded as the local detection area of the laser sensor in the current environment, and the area between the detection angles A11 and B11 in FIG. 2(a) is shown as an example, which is the current detection area of the robot at position R21, including unknown areas and / or known areas, wherein the boundary points in the current detection area include points in the boundary line of the current detection area (limited by the scanning distance and scanning range of the laser sensor) and obstacle contour points in the current detection area. In addition, the boundary points can be understood as points from the contour line in the same working area or points from the boundary line between different working areas, and the different working areas constitute connected areas.

[0037] In step A, the current position of the robot is at a pre-searched front boundary point; the pre-searched front boundary point is determined before the current step A is performed. The front boundary point disclosed in the present application is equivalent to the preset boundary point disclosed in the Chinese invention patent with patent application number CN202210787428.X, and correspondingly, the map to be optimized disclosed in the present application is equivalent to the map disclosed in the Chinese invention patent with patent application number CN202210787428.X. Preferably, the robot will set the front boundary point using the points in the preset boundary line.

[0038] In step B, the two ends of the preset boundary line are respectively controlled to expand to obtain a preset boundary expansion line segment; in the case that the expansion lengths of the two ends of the preset boundary line are both less than or equal to the preset perception radius, it is judged whether the two ends of the preset boundary expansion line segment both intersect with the target contour line, here it can be judged that the two ends of multiple preset boundary expansion line segments intersect with the target contour line, if the two ends of the preset boundary expansion line segment both intersect with the target contour line, step C is performed, at this time the preset boundary expansion line segment can be set as the target boundary line, which is equivalent to selecting the target boundary line from multiple preset boundary expansion line segments; otherwise, it is determined that the robot fails to track the front boundary point, and the search of the front boundary point is not performed, so as to prevent the robot from searching in a remote area or a connected area outside the indoor environment (deviating from the area to be mapped).

[0039] In step B, the two ends of the preset boundary line are respectively controlled to expand to obtain a preset boundary expansion line segment; in the case that the expansion lengths of the two ends of the preset boundary line are both less than or equal to the preset perception radius, it is judged whether the two ends of the preset boundary expansion line segment both intersect with the target contour line, here it can be judged that the two ends of multiple preset boundary expansion line segments intersect with the target contour line, if the two ends of the preset boundary expansion line segment both intersect with the target contour line, step C is performed, at this time the preset boundary expansion line segment can be set as the target boundary line, which is equivalent to selecting the target boundary line from multiple preset boundary expansion line segments; otherwise, it is determined that the robot fails to track the front boundary point, and the search of the front boundary point is not performed, so as to prevent the robot from searching in a remote area or a connected area outside the indoor environment (deviating from the area to be mapped).

[0040] The two ends of the preset demarcation extension line segment intersecting with the target contour line are both target demarcation lines, as shown in the line segment A11B11 of FIG. 3(a) or the line segment A12B12 of FIG. 3(b). The illustrated target demarcation line A11B11 is regarded as a wall contour line PB11 perpendicular to the lower side of the corridor region, and the illustrated target demarcation line A12B12 is regarded as a wall contour line PB12 perpendicular to the lower side of the corridor region, thereby dividing the left unknown region and the right known region. The target demarcation line is not parallel to the wall contour line on both sides, preventing the front boundary point in the target demarcation line from being close to the wall on both sides of the corridor region (parallel to the walking direction of the robot).

[0041] Step C, based on the preset demarcation extension line segment, the robot divides a to-be-tracked contour line from the target contour line in a direction connected to the unknown region; since the preset demarcation extension line segment divides the unknown region and the known region, and the known region is a region that has been scanned by the robot, it is necessary to divide the to-be-tracked contour line from the target contour line in a direction connected to the unknown region by using the preset demarcation extension line segment (equivalent to the target demarcation line), so that the region in which the to-be-tracked contour line is located includes the unknown region required to be detected by the robot. Then the robot searches for the front boundary point from the region surrounded by the to-be-tracked contour line and the preset demarcation extension line segment (equivalent to the target demarcation line), realizes searching for each front boundary point set in advance in the extension direction of the to-be-tracked contour line, that is, tracking the corresponding front boundary point in the unknown region along the to-be-tracked contour line, and then Step D is performed.

[0042] It should be noted that the region in which the to-be-tracked contour line is located will contain the front boundary point in the preset demarcation extension line segment and the subsequent expanded map region, including the subsequent unknown region to be detected; specifically, the unknown region refers to a region that has not been explored by the robot and the map has not been completed, the known region refers to a region that has been explored by the robot and the map has been completed, and the preset demarcation line refers to a line segment intersecting the adjacent unknown region in the known region. The front boundary point in the present application is understood as a node, a path node, or a tree node of a random tree growth on the map, which is endowed with the meaning of a node in the corresponding scene in the specific exploration step, and can be represented by a corresponding attribute grid.

[0043] If the robot traverses the corridor region and walks to the position point R23, the to-be-tracked contour line is segmented, as shown in FIG. 3(c), the contour lines and the boundary lines of all the detectable regions in the room region and the corridor region on the right side of the preset boundary extension line segment (equivalent to the target boundary line) A12B12 are sequentially connected, specifically, the contour line of the lower side of the wall A12C, the boundary line CU, the contour line of the left side of the wall UH, the contour line of the upper side of the wall HI, the boundary line IT, the contour line of the left side of the wall TS, the boundary line SO, the contour line of the upper side of the wall OQ, the boundary line QP, and the contour line of the upper side of the wall PB12 are sequentially connected; meanwhile, the traversed contour line is sequentially connected by the contour lines in the four connected room regions above and below the preset boundary extension line segment (equivalent to the target boundary line) A12B12 and the corridor region on the left side of the preset boundary extension line segment A12B12, wherein the four connected room regions above and below the preset boundary extension line segment (equivalent to the target boundary line) A12B12 and the corridor region on the left side of the preset boundary extension line segment A12B12 are all the detectable regions in the walking process of the robot on the left side of the preset boundary extension line segment (equivalent to the target boundary line) A12B12.

[0044] In the region surrounded by the to-be-tracked contour line and the preset boundary extension line segment (equivalent to the target boundary line), the searched each front boundary point is, as shown in FIG. 3(c), the front boundary point R23 in the boundary line A12B12 (corresponding to the position point R14 in FIG. 3(b)), the front boundary point F18 in the boundary line PQ, the front boundary point F17 in the boundary line OS, the front boundary point F16 in the boundary line TI, and the front boundary point F15 in the boundary line CU are sequentially searched in the counterclockwise direction. The boundary lines where these front boundary points are located can all be regarded as the boundary lines between the known region and the unknown region of the robot or the target boundary line or the preset boundary extension line segment.

[0045] It should be noted that the acquisition order between the preset boundary extension line segment and the front boundary point is not limited, and there is no dependency relationship between them; it can also be understood that the to-be-tracked contour line is segmented from the target contour line by using the preset boundary extension line segment, and then it is determined whether to search the front boundary point, and if the segmented to-be-tracked contour line or the region thereof has no front boundary point, the search is stopped.

[0046] In step C, if there is no front boundary point in the region surrounded by the to-be-tracked contour line and the preset boundary extension line segment, the search of the front boundary point is stopped; specifically, the robot scans all the regions needing to construct the map by the laser sensor to obtain a global map, and after steps A to C are performed, all the front boundary points in the global map are searched, and then the search of the front boundary point is stopped.

[0047] By performing step C to search for front boundary points in the area enclosed by the to-be-tracked contour line together with the preset boundary extension line segment, each front boundary point searched by step C is a subset of all front boundary points found within the range of the to-be-optimized map, and the search rate is faster than directly searching for a front boundary point leading to an unknown area on the target tracking contour line, thereby improving the mapping efficiency.

[0048] Step D: filtering out reachable boundary points according to the passability of the front boundary points searched in step C and orderly saving the reachable boundary points, so that the direction in which the lines connecting each reachable boundary point accessed by the robot in sequence extend simulates the direction in which the robot walks along the target contour line, for example, the reachable boundary points are preset to be sequentially sorted in a clockwise direction, and the reachable boundary point with the first preset clockwise direction is preferentially accessed; then the robot can track the front boundary points / reachable boundary points along the to-be-tracked contour line one by one, and the distance span between two front boundary points accessed in sequence is formed, rather than always approaching the wall of the area where the robot is located; compared with the boundary point traversal mode of the prior art in which the boundary points are traversed one unit distance at a time, the speed of setting a target point in Chinese Patent CN202110264567.X is at least accelerated, and the speed of robot mapping and navigation is provided.

[0049] In step D, the passability of the front boundary points searched in step C includes that the robot walks to the front boundary point and the robot walks along the boundary line where the front boundary point is located, which at least embodies the effect that the boundary line where the front boundary point is located or the neighborhood of the front boundary point can accommodate the complete body of the robot to walk or walk on a trajectory parallel to the corresponding boundary line, and in some embodiments, it is manifested as the passability of the robot walking along the obstacle contour line, based on which the reachable boundary points are filtered out, and the number of the reachable boundary points can be one or more.

[0050] If necessary, the front boundary points that satisfy the passability and are filtered out need to be repeatedly checked to remove the reachable boundary points that are repeatedly filtered out, and after the repeatedly filtered out reachable boundary points are removed, the robot is assigned to explore the unknown area and search for new reachable boundary points and establish a map for the unknown area, thereby reducing the redundant and repeated front boundary points generated in the exploration process of the robot, forming a distance span between two reachable boundary points accessed in sequence, and improving the efficiency of tracking the reachable boundary points in the map.

[0051] Compared with the prior art, the preset boundary line is first fitted by using the detected boundary points, and the intersection of the preset boundary line after expansion with the target contour line is determined by expanding the preset boundary line, so as to segment the to-be-tracked contour line from the target contour line, then only the front boundary points in the region range related to the to-be-tracked contour line are searched, and after the passability test, the to-be-tracked contour line is sequentially assigned to the robot for navigation and mapping, thereby being applicable to the scene in which the robot needs to quickly explore the map of an unknown region, optimizing the mapping process, and achieving the effect of fast mapping.

[0052] Since the to-be-tracked contour line is segmented from the target contour line by using the result of the expansion of the preset boundary line, the robot only selects the reachable boundary points in the region range corresponding to the to-be-tracked contour line, so that the robot not only reduces the search amount and the calculation amount, but also can navigate and map the unknown region according to a certain distance span, thereby overcoming the problem that the distance between two adjacent navigation points is shorter and the mapping similarity is higher in the process of robot mapping / exploring the map, and improving the efficiency of robot exploration of the map.

[0053] Based on the foregoing embodiment, in step C, when the preset boundary expansion line segment intersects with the target contour line, the target contour line is segmented into a traversed contour line and a to-be-tracked contour line by the preset boundary expansion line segment, that is, the target boundary line segments the target contour line into the traversed contour line and the to-be-tracked contour line; then the region on one side of the traversed contour line is marked as existing a known region, specifically, the part of the connected region that has been detected in the region on one side of the traversed contour line is marked as the known region, and the region on one side of the traversed contour line is the region on one side of the preset boundary expansion line segment in all the aforementioned connected detectable regions, so as to include the region that does not need to be tracked at present; meanwhile, the region on one side of the to-be-tracked contour line is marked as existing an unknown region, specifically, the part of the connected region that has not been detected in the region on one side of the to-be-tracked contour line is marked as the unknown region, and the region on one side of the to-be-tracked contour line is the region on the other side of the preset boundary expansion line segment in all the aforementioned connected detectable regions, so as to include the region that needs to be tracked at present and in the future. It should be noted that the region surrounded by the to-be-tracked contour line and the preset boundary expansion line segment is the region on one side of the to-be-tracked contour line. Therefore, the preset boundary expansion line segment is the boundary between the known region and the unknown region obtained by scanning by the laser sensor in the current field of view, or the preset boundary expansion line segment is the boundary between the region that does not need to be tracked at present and the region that needs to be tracked.

[0054] The region on one side of the traversed contour line and the region on one side of the to-be-tracked contour line form a preset working region, and the preset working region is the working environment in which the robot is currently located; the preset working region includes all the aforementioned connected detectable regions, and also includes the current detection region.

[0055] The preset working area is composed of a corridor area and a plurality of unit working areas, each of which is connected to the corridor area; the target contour line is the maximum contour line that can be detected by the laser sensor when the robot walks in the corridor area, and is distributed to part or all of the unit working areas; the composition of the target contour line can be understood as that when the robot walks in all passable positions in the corridor area, each contour line that can be detected by the laser sensor is sequentially connected to form the target contour line.

[0056] It can be understood that the area to which the target contour line is distributed constitutes the connected detectable area; preferably, the longest contour length of the corridor area is greater than the longest contour length of each unit working area.

[0057] As an embodiment, before step A is performed, if the robot does not walk from the current position to the reachable boundary point (which can also be understood as the front boundary point in the preset boundary line), the robot marks the current detection area as an unknown area before performing the current map repairing operation, which is equivalent to marking the current detection area in the side of the traversed contour line segmented in the last time as an unknown area, and marking the connected area in the side of the to-be-tracked contour line segmented in the last time as an unknown area; at this time, the area in the side of the traversed contour line is regarded as an unknown area; it can also be understood that before the map repairing operation is performed, the preset boundary line has not been fitted and the reachable boundary point has not been searched, and part or all of the area in the current detection area is marked as an unknown area; at this time, the preset boundary line is located in the unknown area to be explored by the robot, and the reachable boundary point needs to be screened out after the map repairing operation is performed by performing steps A to D to further screen out the reachable boundary point; generally, the reachable boundary point has a corresponding relationship with the preset boundary extension line segment, and the reachable boundary point can be understood as being located in the preset boundary extension line segment.

[0058] As shown in Fig. 2(a), when the robot is currently in the corridor area, there are: the robot is at position R21, has not started to perform step A, and has not walked to the reachable boundary point F13 shown in Fig. 2(b), at this time, the part of the area of each rectangular room area (separated by the corresponding skeleton) and the corridor connected to the left side of the detection angle A11R21B11 (also referred to as the outer side of the detection angle A11R21B11) of the robot are known areas; the part of the area of each rectangular room area and the corridor connected to the right side of the detection angle A11R21B11 (also referred to as the inner side of the detection angle A11R21B11) of the robot is an unknown area, at this time, the robot has not started to perform the map repairing operation on the inside of the detection angle A11R21B11 (equivalent to the triangular area A11R21B11 disclosed in Fig. 2(b)), the current detection area of the robot can be regarded as the inside of the detection angle A11R21B11, and the part of the area of each rectangular room area and the corridor connected to the right side of the detection angle A11R21B11 (also referred to as the inner side of the detection angle A11R21B11) is regarded as the connected area in the side of the last segmented contour line to be tracked.

[0059] After performing the current map repairing operation, the robot marks the current detection area in the side of the traversed contour line as a known area, and marks the side of the contour line to be tracked as an area with unknown areas; wherein after performing the current map repairing operation, the traversed contour line and the contour line to be tracked are segmented by performing steps A to D using the preset boundary extension line segment, and the reachable boundary point is screened out. Therefore, the map repairing operation is performed once before each execution of step A.

[0060] As shown in Fig. 2(b) and Fig. 3(a), the robot performs a map repairing operation on the triangular area A11R21B11 at position R21, at this time, the robot processes the current detection area R21A11B11 as a known area R21A11B11, i.e., the unknown area R21A11B11 detected before the map repairing operation in Fig. 2(a) forms the known area R21A11B11 after the map repairing operation in Fig. 2(b), so that the robot processes the current detection area in the side of the traversed contour line as a known area, and the part of the area of each rectangular room area and the corridor connected to the right side of the line segment A11B11 is an unknown area, therefore, the unknown area in Fig. 2(b) and Fig. 3(a) is reduced relative to the unknown area in Fig. 2(a).

[0061] After the robot walks from the current position to the reachable boundary point and performs a new map repairing operation, by performing steps A to D, the new to-be-tracked contour line and the new reachable boundary point are determined in turn, and relative to the region on one side of the new to-be-tracked contour line, the region on one side of the last segmented to-be-tracked contour line is added to the known region, and the contour line of the last segmented to-be-tracked contour line in the added known region is configured as the traversed contour line, while the last segmented traversed contour line remains unchanged, so that the current segmented traversed contour line is extended relative to the last segmented traversed contour line, while the target contour line remains unchanged, and the current segmented to-be-tracked contour line is reduced.

[0062] The added known region includes the current detection region generated after the robot walks to the reachable boundary point and performs a new map repairing operation.

[0063] Illustratively, by comparing FIG. 3(a) and FIG. 3(b), it can be seen that when the robot is currently in the corridor region, there is: the robot walks from position R21 (corresponding to the current position) to position R22 (corresponding to the position of the front reachable boundary point F13 in FIG. 3(a), located in the preset expansion boundary line segment A11B11) to detect the reachable boundary point F14, and after performing a map repairing operation, the current detection region R22A12B12 is processed as a known region, at this time, each rectangular room region and part of the corridor region connected on the left side of the preset expansion boundary line segment A12B12 are known regions, and the known region R22A12B12 is added relative to FIG. 3(a) or FIG. 2(b), while each rectangular room region and part of the corridor region connected on the right side of the preset expansion boundary line segment A12B12 are unknown regions to reduce relative to the unknown regions in FIG. 3(a) or FIG. 2(b).

[0064] In summary, as the robot walks in the corridor region according to the reachable boundary point, the map repairing operation is performed to update the boundary region between the known region and the unknown region, and at least the unknown region in the current detection region is updated, thereby optimizing the mapping of the corridor region and speeding up the exploration of the map of the corridor region and each rectangular room region (separated by the corresponding skeleton) connected thereto. Based on the repaired map of the corridor region, the reachable boundary points assigned to the subsequent walking of the robot are more reasonable, the exploration distance is more reasonable, the exploration trajectory is prevented from being closer and closer to the contour (closer and closer to the edge), and the exploration efficiency of the robot is improved.

[0065] In some embodiments, after the robot starts walking from the initial position, each time the robot walks to a reachable boundary point in the corridor area, a map repairing operation is performed, and the next reachable boundary point screened out by step D after the map repairing operation is performed to guide the robot to walk along the contour line to be tracked to the next reachable boundary point. Wherein, the reachable boundary point where the robot is currently located is in the preset boundary extension line segment extended by the robot at the last reachable boundary point walked through, and step B. In this embodiment, in order to explore the map of the unknown area, each reachable boundary point walked through by the robot is in the preset boundary extension line segment extended by the robot at the last reachable boundary point (which can be understood as the last reachable boundary point walked through or visited) through the execution of step B.

[0066] Illustratively, the robot walks in the corridor area shown in FIG. 3 from position R21 to the reachable boundary point F13 (corresponding to position R22) in the preset extension boundary line segment A11B11 shown in FIG. 3(a) and the reachable boundary point F14 (as the next reachable boundary point) in the preset extension boundary line segment A12B12 shown in FIG. 3(b) in sequence, wherein the known area R21A11B11 and the new reachable boundary point F13 are set on the boundary line (the preset boundary extension line segment A11B11) between the right side undetected area, and the known area R22A12B12 and the new reachable boundary point F14 are set on the boundary line (the preset boundary extension line segment A12B12) between the right side undetected area; by analogy, in order to continue the rectangular room area above and below the entire corridor area in the to-be-optimized map, the robot can walk through the reachable boundary points F15, F16, F17 and F18 in the clockwise direction according to the contour line to be tracked in FIG. 3(c), and the current detected area R23QOST of the laser radar is processed as a known area through the map repairing operation, which corresponds to the known area R23QOST in the to-be-optimized map. The access starting point of the unknown area below the known area R23QOST is the reachable boundary point F17, so that the starting point of the robot to detect the new reachable boundary point in the unknown area below the known area R23QOST is the reachable boundary point F17. Thus, the robot performs map repairing and explores a larger range of unknown areas during the walking process in the long corridor.

[0067] In this way, the robot obtains a new reachable boundary point / frontier boundary point each time it walks, and traverses all the frontier boundary points in the to-be-optimized map by moving and extending the preset extension boundary line and screening the reachable boundary points, until there is no new frontier boundary point in the to-be-optimized map, then a complete map is established, and the robot ends the autonomous exploration according to the reachable boundary point.

[0068] In some embodiments, when the robot walks from the current position to the reachable boundary point in the last execution of step D, the robot re-divides the target contour line into the traversed contour line and the to-be-tracked contour line by executing steps A to C again, i.e., repeatedly executing a round of steps A to C, to mark the area covered by the current detection area as a known area by performing a map repairing operation in the area on the side of the to-be-tracked contour line divided in the last execution of step C, specifically, performing the map repairing operation before the current execution of step A, and marking the area covered by the current detection area as a known area in the area on the side of the to-be-tracked contour line divided in the last execution of step C, which corresponds to the newly added known area.

[0069] In the process of walking in the corridor area, the distance between the reachable boundary point screened out by the robot in the last execution of step D and the preset boundary extension line segment extended by step B in the current execution is a preset distance, preferably a fixed distance, wherein the reachable boundary point screened out by step D is derived from the front boundary point preset in the to-be-optimized map, and the starting line segment required for step B to extend the preset boundary extension line segment is a preset boundary line, and the distance between the preset boundary line and the current position of the robot is a preset fixed distance; or the preset boundary line can also be associated with the corresponding boundary point in the current detection area formed by the laser sensor at the current position of the robot, i.e., the distribution position of the preset boundary line changes with the change of the position covered by the current detection area.

[0070] Illustratively, as shown in FIGS. 3(a) and 3(b), the robot detects the front boundary point F13 at position R21 (regarded as the reachable boundary point screened out by step D in the last execution) in FIG. 3(a), at this time, the preset boundary extension line segment A11B11 is extended by step B, and the reachable boundary point F13 is determined by step D, so the distance between position R21 and the preset boundary extension line segment A11B11, and the distance between position R21 and the reachable boundary point F13 are determined. Then the robot walks from position R21 in FIG. 3(a) to position R22 (corresponding to the reachable boundary point F13 in FIG. 3(a)) in FIG. 3(b), detects the front boundary point F14, at this time, the preset boundary extension line segment A12B12 is extended by step B at position R22, and the reachable boundary point F14 is determined by step D, so the distance between position R22 and the preset boundary extension line segment A12B12, and the distance between position R22 and the reachable boundary point F14 are determined. In the case of no obstacle blocking, the distance between position R22 and the preset boundary extension line segment A12B12 can be equal to the distance between position R21 and the preset boundary extension line segment A11B11.

[0071] Compared with the prior art, the foregoing embodiment sets a distance span between different mapping points (i.e., different reachable boundary points), thereby exploring unknown regions in a farther unknown region and constructing a map, and avoiding the phenomenon of repeated mapping because the mapping points are too close, specifically, repeated mapping in the current detection region of the laser sensor because the navigation points in the corridor region are increasingly short.

[0072] As an embodiment, as shown in FIG. 6, step B specifically comprises:

[0073] Step B1: respectively taking two end points of the preset boundary line as two extension starting points, performing outward extension in a corresponding extension direction by a corresponding step length, respectively obtaining two extension line segments and two corresponding extension position points, and then forming an extension result of the preset boundary line by combining the preset boundary line and the two extension line segments to form a preset extension boundary line; and then performing step B2. In step B1, the corresponding step length is an extension radius set according to an experience value, and is preferably 2 m. The corresponding step length can also be set according to the robot mapping scene, and the maximum value of the corresponding step length can be set as the maximum scanning distance of the laser sensor.

[0074] The two extension line segments are line segments extended from the two end points of the preset boundary line in each execution of step B1, and respectively serve as extension line segments of the two ends of the preset boundary line. In step B1, the extension directions corresponding to the two extension starting points are opposite, and remain unchanged in each execution of step B1.

[0075] In FIG. 3(a), the corresponding extension direction is a direction extending from the front boundary point F13 to the intersection point A11 and the intersection point B11, and is preferably perpendicular to the horizontal wall of the corridor region; the two corresponding extension position points are respectively located inside the line segment A11B11; and the corresponding step length is limited to be less than the width of the corridor region. When the front boundary point F13 is the midpoint of the preset boundary line or the line segment AB, the corresponding step length is less than half of the width of the corridor region.

[0076] In FIG. 3(b), the corresponding extension direction is a direction extending from the front boundary point F14 to the intersection point A12 and the intersection point B12, and is preferably perpendicular to the horizontal wall of the corridor region; the two corresponding extension position points are respectively located inside the line segment A12B12; and the corresponding step length is limited to be less than the width of the corridor region. When the front boundary point F14 is the midpoint of the preset boundary line or the line segment A12B12, the corresponding step length is less than half of the width of the corridor region.

[0077] Step B2, judging whether there is at least one of the lengths of the two extended line segments greater than the preset sensing radius, if yes, determining that the preset boundary line extension fails, i.e. the target boundary line cannot be obtained; otherwise, determining that the lengths of both ends of the preset boundary line are less than or equal to the preset sensing radius, and performing step B3; wherein the preset sensing radius is the maximum scanning distance of the laser sensor.

[0078] Step B3, judging whether there is at least one of the lengths of the two extended line segments equal to the preset sensing radius, if yes, performing step B4, otherwise performing step B5.

[0079] Step B4, judging whether the two extended line segments both intersect with the target contour line, if yes, obtaining the intersection points of the two extended line segments and the target contour line and performing step C, at this time, it is determined that in the case that there is at least one of the lengths of the two extended line segments equal to the preset sensing radius, both ends of the preset boundary extension line segment intersect with the target contour line, and the preset boundary extension line segment is configured as the target boundary line; otherwise, it is determined that the preset boundary line extension fails, i.e. the target boundary line cannot be obtained.

[0080] Step B5, judging whether the two extended line segments both intersect with the target contour line, if yes, obtaining the intersection points of the two extended line segments and the target contour line and performing step C, at this time, it is determined that in the case that there is at least one of the lengths of the two extended line segments less than the preset sensing radius, both ends of the preset boundary extension line segment intersect with the target contour line, and the preset boundary extension line segment is configured as the target boundary line; otherwise, updating the two corresponding extension position points to the two extension starting points in step B1, and performing step B1 again to continue extending from the updated two extension starting points in the corresponding extension directions.

[0081] Illustratively, in FIG. 3(a), the two extended line segments intersect with the target contour line at point A11 and point B11 respectively; in FIG. 3(b), the two extended line segments intersect with the target contour line at point A12 and point B12 respectively. Wherein, the contour lines A11D and B11P in FIG. 3(a) and the contour lines A12D and B12P in FIG. 3(b) are both a part of the target contour line in the corridor region.

[0082] Therefore, the embodiment requires that at least one of the two extended line segments has a length equal to the preset sensing radius and intersects the target contour line in order to perform step C. The embodiment is suitable for determining when to use the extension result (preset boundary extension line segment) of the preset boundary line to divide the target contour line in the corridor area. When the two ends of the preset boundary extension line segment intersect the two side walls of the corridor area, the preset boundary extension line segment and the front boundary points distributed inside and around the preset boundary extension line segment will not approach the two side walls of the corridor area in the process of extension according to step B1, so that the map constructed by the robot in the process of walking to different front boundary points will not be excessively similar. Subsequently, by performing step C, the unknown area and the known area are divided from the corridor area, and the contour line extending from the known area in the corridor area to the unknown area outside the corridor area is obtained, and then step D is performed to search for the front boundary point between the two side walls of the corridor area along the to-be-tracked contour line instead of searching for the front boundary point close to the wall.

[0083] In summary, in the process of extending the preset boundary line to the two ends thereof, when the extension length of one end or both ends of the preset boundary line reaches the preset sensing radius, if at least one of the two corresponding obtained extension line segments fails to intersect the target contour line, it is considered that the extension fails, and then step C and step D are stopped, the to-be-tracked contour line is not divided, and the front boundary point is not searched along the to-be-tracked contour line, so that it is determined that the front boundary point tracking ends. In the case where the extension lengths of the two ends of the preset boundary line are both less than or equal to the preset sensing radius, if the two corresponding obtained extension line segments can both intersect the target contour line, step C is performed to divide the to-be-tracked contour line and search for the front boundary point along the to-be-tracked contour line; so as to simulate that the robot scans the wall contour on both sides of the walking direction in the corridor area by using the laser sensor, and then determines whether to continue tracking the front boundary point based on the intersection of the two extension line segments and the wall contour on both sides.

[0084] As an embodiment, in the step A, the method for the robot to fit the preset boundary line by using the boundary points in the current detection area comprises:

[0085] The robot scans the boundary points of the current detection area by using the laser sensor, wherein the distance between the boundary points and the current position of the robot is less than or equal to the scanning distance of the laser sensor; for the specific definition of the boundary points in the current detection area and inside the current detection area, refer to the foregoing embodiments, which will not be described here.

[0086] According to the straight line fitting algorithm, the preset boundary line is fitted by using the boundary points in the current detection area. Specifically, the corresponding preset boundary line can be fitted according to each boundary of the current detection area. Subsequently, the corresponding preset extended boundary line is extended by step B, and in the process of extending each preset boundary line, steps B1 to B5 mentioned in the foregoing embodiments are sequentially executed to filter out the preset boundary extended line segment from the extension results of the preset boundary lines fitted in step A, which is intersected with the target contour line at both ends and has an extension length less than or equal to the preset perception radius at both ends, as the target boundary line.

[0087] Preferably, the straight line fitting algorithm selects the Hough algorithm or the least square method, so that the boundary points scanned by the laser sensor at the same position are used for straight line fitting to obtain the preset boundary line at a distance from the current position of the robot, and the preset boundary line is a line segment with a certain length, and multiple preset boundary lines can be fitted at the same time.

[0088] In some embodiments, after the local area (for example, the current detection area of the robot) of the to-be-optimized map is subjected to the map repairing operation, the preset boundary line is used to divide the known area and the unknown area in the to-be-optimized map. When applied to a corridor area, the length of the preset boundary line is less than the width of the corridor area and is arranged between the two side walls of the corridor area, so that the preset boundary line needs to be extended by performing step B to make both ends of the preset boundary line extended to intersect with the target contour line and to intersect with the target contour line when the extension length of both ends of the preset boundary line is less than or equal to the preset perception radius. Then, the to-be-tracked contour line is divided from the target contour line by performing step C, and the known area and the unknown area are also divided in the corridor area. Preferably, the width of the corridor area is less than the length of the longest contour line (the longest wall contour) of the corridor area.

[0089] In some embodiments, the front boundary point is obtained by clustering analysis or midpoint extraction of the points in the preset boundary line, so that one front boundary point corresponds to one preset boundary line. The front boundary point can be set to be located in the preset boundary line. As shown in FIG. 3(c), the robot walks to the position R23 (corresponding to the position of the front boundary point F14 in FIG. 3(b)) and sequentially detects the front boundary points F15, F16, F17 and F18 in the clockwise direction, wherein the line segment CU passes through the front boundary point F15 and the line segment CU is the boundary line at the front boundary point F15 or the result of its extension (regarded as a preset extended boundary line CU), the line segment IT passes through the front boundary point F16 and the line segment IT is the preset boundary line at the front boundary point F16 or the result of its extension (regarded as a preset extended boundary line IT), and the line segment PQ passes through the front boundary point F18 and the line segment PQ is the preset boundary line at the front boundary point F18 or the result of its extension (regarded as a preset extended boundary line PQ).

[0090] Based on the foregoing steps A to D, the front boundary point is configured as the position of the robot when fitting a new preset boundary line and extracting a new front boundary point, and then screening the reachable boundary point from the front boundary point.

[0091] As an embodiment, the method for performing the map repairing operation comprises:

[0092] Step 1: After the robot constructs the to-be-optimized map by using the laser point cloud, the to-be-optimized map is a grid map at this time. The pose data of the robot and the laser point cloud in the current detection area is obtained from the to-be-optimized map, and then step 2 is performed. The pose data obtained in step 1 in the current detection area includes the pose data of the current position of the robot and the pose data of the laser point cloud collected in the current detection area, which are respectively used to locate the robot and the detectable area range around the robot in the to-be-optimized map.

[0093] Step 2: The pose data obtained in step 1 is processed according to the digital integration method to convert the mask. The processing of the digital integration method can prevent the mask converted by the laser point cloud from being distorted due to the missing of the point cloud. Then step 3 is performed.

[0094] Step 3, converting the area covered by the mask in the to-be-optimized map in step 1 into a passable area, and marking part of the unknown area as a known area; wherein the area covered by the mask in the to-be-optimized map in step 1 is considered as the area where the mask and the to-be-optimized map overlap, which is the area that the robot needs to map in the current detection area. Then the to-be-optimized map converted by the mask into the passable area is configured as the to-be-optimized map in step A. Thus, the map repairing operation is performed once before each execution of step A; and then the next reachable boundary point is screened out by executing steps A to D after performing the map repairing operation once.

[0095] Based on the foregoing steps 1 to 3 and the foregoing steps A to D, after performing the map repairing operation on the to-be-optimized map, a certain distance span of the passable area is marked for the robot to navigate and map in the unknown area in advance, and the reachable boundary point can be configured for the junction line (the target boundary line or the preset extended boundary line) between the passable area and the unknown area to guide the robot to walk to the reachable boundary point to continue scanning the laser point cloud and constructing the map.

[0096] As the robot walks in the corridor area according to the reachable boundary point, the boundary area between the known area and the unknown area is updated through the map repairing operation, at least the unknown area in the current detection area is updated, thereby optimizing the mapping of the corridor area and speeding up the exploration of the map of the corridor area and each rectangular room area (separated by the corresponding skeleton) connected thereto. Based on the repaired map of the corridor area, the reachable boundary point assigned to the subsequent walking of the robot is more reasonable, the exploration distance is more reasonable, and the exploration trajectory is prevented from being closer and closer to the contour (closer and closer to the edge), thereby improving the exploration efficiency of the robot. As the robot walks in the corridor area according to the reachable boundary point and performs the map repairing operation, the unknown area in a farther unknown area is explored and mapped, and the phenomenon of repeated mapping due to too close mapping points is avoided, specifically, repeated mapping in the current detection area of the laser sensor due to too short navigation points in the corridor area is avoided.

[0097] Specifically, the step 2 specifically includes:

[0098] According to the digital integration method, the pose data obtained in step 1 is processed to obtain a template, which is a polygon image template integrated according to the shape of the current detection area; specifically, the digital integration method is an interpolation algorithm established on the basis of calling a digital integrator by the robot, which is easy to realize the linkage of multiple pose points (multiple boundary points) coordinates in the current detection area, and the template is obtained through the interpolation of a quadratic curve or a high-order curve.

[0099] Then, according to the template, a filling algorithm is performed on the corresponding empty map area to convert the corresponding empty map area into a mask, which is equivalent to drawing the template on the pre-set empty map and performing a filling algorithm on the area covered by the template to obtain a mask, so that the pixel values of each position point in the area covered by the mask are all assigned a preset value; wherein the corresponding empty map area is composed of position points corresponding to the pose data in the current detection area, and each position point has no marked environment information, but only provides a certain range of area until it is converted into a mask through the filling algorithm; the area of the mask is greater than or equal to the area of the corresponding empty map area.

[0100] Specifically, when the filling algorithm is executed, in the empty map area corresponding to the template, the nodes in the vicinity connected to the origin of the map coordinate system are extracted or filled into different pixel gray values, and whenever the filling (which can be understood as expansion) is performed into the neighborhood of the passable position point, the front boundary point or the boundary point exists, and the filling is maintained to the obstacle point. Whether traversing the obstacle point in the target contour line or traversing the front boundary point (and the data saved before step 1 is executed), it is read out from the linear storage space, so that the filling direction or expansion direction of the filling algorithm is orderly and followable. It should be noted that the neighborhood of the passable position point can be the four-neighborhood of the passable position point; according to the filling algorithm, each expansion to a new passable position point is regarded as filling the map to a new passable position point, and the expansion end point of the filling algorithm includes the obstacle point; wherein the passable position point expanded by the robot using the filling algorithm is a pixel point of the passable position, and is connected to the origin of the map coordinate system, so that the robot walks to the obstacle point according to the expanded passable points from the origin of the map coordinate system, and stops executing the filling algorithm when the robot is hindered by the obstacle point. Before expanding to the obstacle point, the pixel points filled by the robot are all passable position points of the robot filled with the same color to distinguish the boundary lines of other adjacent areas. The filling algorithm mentioned in this embodiment can be a seed filling algorithm or a flood filling algorithm.

[0101] On the basis of the above-mentioned embodiments, step 3 specifically comprises: using the mask to extract the overlapping map area in the to-be-optimized map, which is equivalent to performing an AND operation on the mask and the to-be-optimized map in image processing to extract the overlapping map part as the overlapping map area; and then marking each position point in the overlapping map area as a passable position point to form a passable area, so as to mark the unknown area in the overlapping map area as a known area, and determine the area covered by the current detection area in the to-be-optimized map as a known area. Since the area of the mask is greater than or equal to the area of the corresponding empty map area, the overlapping map area includes the area covered by the current detection area in the to-be-optimized map.

[0102] Then the composed passable region replaces the corresponding covered map region in the to-be-optimized map, so that the to-be-optimized map corresponding to the replaced map region is updated to the to-be-optimized map in step A, and the updated to-be-optimized map can be used in steps A to D. The unknown region included in the region covered by the mask in the updated to-be-optimized map is converted into a passable region, a certain distance span of the passable region is marked in advance for the robot to navigate and map in the unknown region, and the mapping efficiency and accuracy in the robot navigation process are improved.

[0103] As an embodiment, the preset boundary extension line segment and the two side boundaries of the current detection region in the robot walking direction form a triangular region, the shape of the mask is a triangle, a triangular passable region is extracted in the to-be-optimized map, the boundary points in the current detection region used in step A are derived from the triangular passable region, and the preset boundary line fitted corresponds to three lines, which correspond to three edges of the triangular passable region, respectively. The detection angle of the laser sensor is arranged in front of the robot with the robot walking direction as the central axis. In the current detection region, the nearest reachable boundary point of the robot in the robot walking direction is arranged at the midpoint of the target boundary line, which is regarded as the midpoint of the bottom edge of the triangular passable region with the current position of the robot as the vertex, and can cover the unknown region or known region in front of the robot.

[0104] As can be seen from FIGS. 2(a) and 2(b), when the robot is currently in the corridor region, there are: in FIG. 2(a), before the robot at position R21 performs the map repairing operation, the robot detects the front boundary point F11 and the front boundary point F12, the part of the region of each rectangular room region (separated by the corresponding skeleton) and the corridor connected to the left side of the detection angle A11R21B11 of the robot (also referred to as the outer side of the detection angle A11R21B11) is a known region, and the part of the region of each rectangular room region and the corridor connected to the right side of the detection angle A11R21B11 of the robot (also referred to as the inner side of the detection angle A11R21B11) is an unknown region. Then, in FIG. 2(b), the robot at position R21 performs the map repairing operation, that is, the robot performs the map repairing operation on the triangular region R21A11B11, at this time, the robot marks the current detection region R21A11B11 as a known region R21A11B11 or a triangular passable region R21A11B11, and then obtains the target boundary line A11B11 and the front boundary point F13 distributed at the midpoint thereof by performing steps A to D.

[0105] As an embodiment, in step D, according to the passability of the front boundary points extracted in step C, the method for screening the reachable boundary points includes:

[0106] The robot first erodes the obstacle points in the to-be-tracked contour line according to a pre-set template image to expand the area occupied by the obstacle where the obstacle points are located; specifically, eroding the obstacle points in the to-be-tracked contour line according to the template image can remove small white points (denoising) near the to-be-tracked contour line in the to-be-optimized map with the erosion operation, and can smooth the boundary of the to-be-tracked contour line without significantly changing the to-be-tracked contour line.

[0107] In the formula, the pre-set template image can not use the aforementioned mask, but can use other templates associated with the area circled by the to-be-tracked contour line, and the expansion radius of the pre-set template image is equal to the body radius of the robot; the obstacle point is a pixel point marked as an obstacle occupied position; the front boundary point can be obtained before the map repair operation is performed; the front boundary point can also be obtained after the map repair operation is performed, for searching by steps A to D in the to-be-optimized map.

[0108] It should be noted that in step D of the present application, the method for detecting the passability of the front boundary point is steps B and C in the target point search method disclosed in the Chinese invention patent application No. CN202210787428.X, and the full contour line is replaced by the to-be-tracked contour line and the pre-set boundary point is replaced by the aforementioned front boundary point.

[0109] Then, the robot performs a filling algorithm along the extension direction of the to-be-tracked contour line in the to-be-optimized map, and judges whether there is a front boundary point in the neighborhood of the passable position point currently filled, and if so, sets the front boundary point as a reachable boundary point; wherein the front boundary point filled by the robot using the filling algorithm is connected to the current position of the robot. If the current position of the robot is configured as the origin of the coordinate system of the to-be-optimized map, the robot starts to perform the filling algorithm from the origin of the coordinate system of the to-be-optimized map, and expands from the origin of the coordinate system along the extension direction of the to-be-tracked contour line towards the corresponding coordinate system quadrant region of the to-be-optimized map, while judging whether there is a front boundary point in the neighborhood of the passable position point currently expanded, and if so, setting the front boundary point as a reachable boundary point; wherein the front boundary point expanded by the robot using the filling algorithm is connected to the origin of the coordinate system. Thus, all the obtained front boundary points are screened according to the passability of the robot along the to-be-tracked contour line.

[0110] In the process of expanding the coordinate system quadrant area of the to-be-optimized map, the neighborhood of the non-zero pixel (passable position point) in the given binary image is expanded, that is, the image is dilated. In some embodiments of the present application, the boundary line of the known area and the boundary line of the adjacent unknown area are dilated by one grid by using a dilation function, so as to obtain the reachable boundary point.

[0111] Preferably, the robot marks the preset expansion boundary line where each front boundary point detected in step D is located as a passable boundary line; when the straight-line distance between the two end points of the passable boundary line is greater than the body diameter of the robot, the effect of accommodating the complete body of the robot to walk on the boundary line or the trajectory line parallel to the boundary line is achieved, and the robot sets the front boundary point (or the midpoint) of the front boundary line as the reachable boundary point.

[0112] The number of reachable boundary points can be one or more, which are derived from the front boundary points previously set in the to-be-optimized map. The preset boundary line or the preset expansion boundary line where the reachable boundary points are located is, in some embodiments, the passability of the robot walking along the obstacle contour line, the passageway between different rooms, the passageway between the room and the corridor area, or the passageway in the same corridor area.

[0113] It is worth noting that the robot remains at the same reachable boundary point during the process of sequentially performing step A, step B, step C, and step D. Each time the robot walks to a reachable boundary point, a round of steps A to D is re-executed; and all of them are performed after the map repair operation on the to-be-optimized map and the front boundary points are marked.

[0114] As an embodiment, in the step D, the reachable boundary points are sequentially saved, so that the direction in which the lines connecting the respective reachable boundary points accessed by the robot in sequence extend simulates the direction in which the robot walks along the target contour line. The method comprises: the robot starts from a search starting point in the to-be-tracked contour line and searches the to-be-tracked contour line in a preset clockwise direction, wherein the search starting point in the to-be-tracked contour line includes the intersection point of the preset boundary expansion line segment and the target contour line determined in step B, specifically including one of the intersection points obtained in the foregoing step B4 or the foregoing step B5; the search starting point in the to-be-tracked contour line can also be an end point of the to-be-tracked contour line or a midpoint of the to-be-tracked contour line.

[0115] When the robot searches a point in the contour line to be tracked, the searched point is marked as a visited point, and whether there is a reachable boundary point in the neighborhood of the visited point is detected. If yes, the reachable boundary point is saved in a linear storage space according to the preset clockwise order, and the reachable boundary point saved in the linear storage space is given priority to be visited. In the process of walking of the robot according to the preset clockwise order, the order of reading the reachable boundary point from the linear storage space simulates the walking order of the robot along the points in the contour line to be tracked. It can be understood that, in the process of walking of the robot according to the preset clockwise order, the order of reading the reachable boundary point from the linear storage space represents the extension direction of the contour line of the work area on one side of the target boundary line, so that the robot only searches and saves the reachable boundary point along the contour line to be tracked, and does not search the reachable boundary point on the other side of the target boundary line.

[0116] In the process of walking of the robot according to the preset clockwise order, the order of reading the reachable boundary point from the linear storage space represents the extension direction of the contour line of the work area on one side of the target boundary line, so that the robot only searches and saves the reachable boundary point along the contour line to be tracked, and does not search the reachable boundary point on the other side of the target boundary line.

[0117] In the process of walking of the robot according to the preset clockwise order, the order of reading the reachable boundary point from the linear storage space represents the extension direction of the contour line of the work area on one side of the target boundary line, so that the robot only searches and saves the reachable boundary point along the contour line to be tracked, and does not search the reachable boundary point on the other side of the target boundary line.

[0118] As an implementation scenario of the robot walking in a corridor area, in the process of searching the contour line to be tracked according to the preset clockwise order, the reachable boundary points are stored in the linear storage space in a tree structure. The specific storage manner includes that the earlier a reachable boundary point is detected in the corridor area, the lower the corresponding configured node depth is, so as to store the earliest detected reachable boundary point as a root node in the tree structure. Each reachable boundary point detected in the corridor area is stored as a node in different layers of the tree structure. It can be understood that, the earlier a reachable boundary point is detected, the earlier the reachable boundary point is stored.

[0119] The node depths corresponding to each of the reachable boundary points detected in the corridor region are all lower than the node depths corresponding to each of the reachable boundary points detected in each of the preset unit work regions; each of the front boundary points detected in each of the preset unit work regions is stored as a node in the same layer of the tree structure; and each of the front boundary points detected in each of the preset unit work regions is stored in turn according to the search direction of the robot (for example, in a clockwise direction in FIG. 3(c)). Illustratively, FIG. 4 is a schematic diagram of the storage of the detected reachable boundary points in a tree structure by the robot according to another embodiment of the present application, wherein the reachable boundary points F15, F16, F17 and F18 are in two preset unit work regions, i.e., two room regions on the right side of FIG. 3(c) and respectively connected to the upper and lower corridor regions, and are all nodes in the same layer of the tree structure in FIG. 4. The nodes in the same layer are called sibling nodes, and the node depths of the nodes in the same layer are equal. The order of access according to the clockwise direction in FIG. 3(c) is F15, F16, F17 and F18 in turn. In FIG. 3(a) and FIG. 3(b), in the corridor region, the reachable boundary point F13 is closer to the position R21 than the reachable boundary point F14, and the reachable boundary point F13 is detected earlier than the reachable boundary point F14 by the robot. Therefore, in the tree structure in FIG. 4, the reachable boundary point F13 and the reachable boundary point F14 are in different layers, the reachable boundary point F13 and the reachable boundary point F14 are in different layers from the reachable boundary points F15, F16, F17 and F18, the node depth of the reachable boundary point F13 is lower than the node depth of the reachable boundary point F14, and the node depth of the reachable boundary point F14 is lower than the node depths of the reachable boundary points F15, F16, F17 or F18. When the reachable boundary point F13 is a root node, the reachable boundary point F13 has a sub-tree F14. When the reachable boundary point F13 is a parent node, the reachable boundary point F14 is a child node. On this basis, the reachable boundary points F15, F16, F17 or F18 are all grandchildren of the reachable boundary point F14.

[0120] In the present embodiment, the corridor region and each of the preset unit work regions are connected, and the contour line to be tracked passes through the corridor region and each of the preset unit work regions in turn. Each of the preset unit work regions is all the unit work regions detected by the laser sensor of the robot at the same position. The current detection region simultaneously has overlapping regions with part or all of the preset unit work regions. Illustratively, when the robot in FIG. 3(c) moves to the position R23, the current detection region includes the region R23IHU and the region R23QOST, and the current detection region has overlapping regions with the rectangular room region EDCUG and the rectangular room region PMOSH, respectively. The rectangular room region EDCUG and the rectangular room region PMOSH are all the unit work regions detected by the laser sensor of the robot at the position R23.

[0121] Therefore, the embodiment can select the front boundary points of the partial area exploration scene in a predetermined time direction by sorting the detected accessible boundary points in the process of the robot following the contour line to be tracked, thereby accelerating the process of searching for accessible boundary points and mapping in the unknown area.

[0122] The application also discloses a chip for storing program code for executing the robot mapping exploration method. The chip controls the robot to fit a preset boundary line with the detected boundary points, and determines the intersection of the preset boundary line after expansion with the target contour line by expanding the preset boundary line, so as to separate the contour line to be tracked from the target contour line, then searches for the front boundary points only in the area range involved in the contour line to be tracked, and subsequently assigns the front boundary points to the robot for navigation and mapping after passing the passability test, thereby being applicable to the scene in which the robot needs to quickly explore the map of the unknown area, optimizing the mapping process, and achieving the effect of fast mapping.

[0123] Since the chip separates the contour line to be tracked from the target contour line by using the result of the preset boundary line after expansion, the robot only selects the accessible boundary points in the area range corresponding to the contour line to be tracked, so that the robot not only reduces the search amount and calculation amount, but also can navigate and map in the unknown area according to a certain distance span, thereby overcoming the problem that the distance between two adjacent navigation points is getting shorter and the mapping similarity is higher in the process of robot mapping / exploring the map, and improving the efficiency of robot exploration of the map.

[0124] Specifically, the chip is arranged on a circuit mainboard in the body of the cleaning robot, and includes a non-transitory memory, such as a hard disk, a flash memory, and a random access memory, and a computing processor, such as a central processing unit and an application processor, in communication. The application processor executes a mapping algorithm, such as SLAM (Simultaneous Localization And Mapping), according to the obstacle information fed back by the visual sensor, draws an instant map of the environment in which the cleaning robot is located and marks the position of the obstacle, and obtains a corresponding terrain contour line. In some embodiments, the distance information and speed information fed back by the laser sensor, the cliff sensor, the drop sensor (a limit switch triggering device), the magnetometer, the accelerometer, the gyroscope, and the odometer arranged on the buffer are combined to comprehensively judge the current working state of the cleaning robot, the position of the cleaning robot, and the current pose of the cleaning robot, such as crossing the threshold, being on the carpet, being located at the step cliff, the dust box being full, being lifted, and the like. Specific next action strategies are given for different situations, so that the work of the cleaning robot is more in line with the requirements of the owner, and better user experience is achieved.

[0125] The above descriptions are only the preferred embodiments of the present application, not intended to limit the present application in other forms. Any skilled person in the art can make changes or modifications to the equivalent embodiments with the disclosed technical contents. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution of the present application and according to the technical essence of the present application still belong to the protection scope of the present application.

Claims

1. A robot map exploration method based on reachable boundary points, the robot map exploration method comprising: a robot acquiring a laser point cloud by laser sensor scanning, and constructing a to-be-optimized map by using the laser point cloud; and characterized in that, The robot map exploration method further comprises: Step A, the robot fits a preset boundary line using boundary points in its current detection area, and selects a contour line for delineating all connected detectable areas in the to-be-optimized map as a target contour line, and then performs step B; Step B, the two ends of the preset boundary line are respectively controlled to expand, and a preset boundary expansion line segment is obtained; in the case that the expansion lengths of the two ends of the preset boundary line are both less than or equal to a preset perception radius, if the two ends of the preset boundary expansion line segment both intersect with the target contour line, step C is performed; Step C, based on the preset boundary expansion line segment, the robot divides a to-be-tracked contour line from the target contour line in a direction connected with an unknown area, and then the robot searches for frontier boundary points from an area enclosed by the to-be-tracked contour line and the preset boundary expansion line segment; then step D is performed; Step D, according to the passability of the frontier boundary points searched out in step C, reachable boundary points are screened out and the reachable boundary points are sequentially saved, so that the direction in which the lines connecting the respective reachable boundary points accessed by the robot in sequence extend simulates the direction in which the robot walks along the target contour line.

2. The robot map exploration method according to claim 1, wherein, In step C, when it is determined that the preset boundary expansion line segment intersects with the target contour line, the target contour line is divided into a traversed contour line and a to-be-tracked contour line by the preset boundary expansion line segment; then the area on one side of the traversed contour line is marked as an area in which a known area exists, and the area on one side of the to-be-tracked contour line is marked as an area in which an unknown area exists; The area enclosed by the to-be-tracked contour line and the preset boundary expansion line segment is the area on one side of the to-be-tracked contour line.

3. The robot map exploration method according to claim 2, wherein, Before each execution of step A, if the robot does not walk from a current position to a reachable boundary point, before the execution of the current map repair operation, the robot marks its current detection area as an area in which an unknown area exists, and after the execution of the current map repair operation, the robot marks the current detection area of the robot in the area on one side of the traversed contour line as a known area; After the robot walks from the current position to the reachable boundary point and performs a new map repair operation, by performing steps A to D, the area on one side of the to-be-tracked contour line divided out in the last time is newly added with a known area, and the contour line of the to-be-tracked contour line divided out in the last time in the newly added known area is configured as a traversed contour line, so as to reduce the to-be-tracked contour line divided out in the current time; wherein the newly added known area includes the current detection area generated after the robot walks to the reachable boundary point to perform the new map repair operation.

4. The robot map exploration method according to claim 3, wherein, After the robot walks from an initial position, each time the robot walks to a reachable boundary point in a corridor area, a map repair operation is performed, and after the execution of the map repair operation, the next reachable boundary point is screened out by performing steps A to D, so as to guide the robot to walk along the to-be-tracked contour line to the next reachable boundary point; The reachable boundary point in which the robot currently stays is in the preset boundary expansion line segment expanded by the robot at the last walked-through reachable boundary point through step B.

5. The robot map exploration method according to claim 4, wherein When the robot walks from the current position to the reachable boundary point screened out in the last execution of step D, the robot re-divides the target contour line into the traversed contour line and the to-be-tracked contour line by executing steps A to C, so as to mark the area covered by the current detection area as a known area by executing a map repairing operation in the area on the side of the to-be-tracked contour line divided in the last execution of step C. The distance between the reachable boundary point screened out in the last execution of step D and the preset boundary extension line segment extended in the current execution of step B is preset.

6. The robot map exploration method according to claim 2, wherein the step B comprises: Step B1, taking the two end points of the preset boundary line as two extension starting points, respectively extending a preset extension step length according to the corresponding extension direction to obtain two extension line segments and two corresponding extension position points, and combining the preset boundary line and the two extension line segments to obtain the preset extension boundary line; and then executing step B2; Step B2, judging whether the length of at least one of the two extension line segments is greater than the preset sensing radius, and if yes, determining that the preset boundary line extension fails, and if not, executing step B3; Step B3, judging whether the length of at least one of the two extension line segments is equal to the preset sensing radius, and if yes, executing step B4, and if not, executing step B5; Step B4, judging whether the two extension line segments intersect with the target contour line, and if yes, obtaining the intersection points of the two extension line segments and the target contour line and executing step C, and if not, determining that the preset boundary line extension fails; Step B5, judging whether the two extension line segments intersect with the target contour line, and if yes, obtaining the intersection points of the two extension line segments and the target contour line and executing step C, and if not, updating the two corresponding extension position points as the two extension starting points in step B1 and executing step B1.

7. The robot map exploration method of claim 6, wherein, In the step A, the method for the robot to fit the preset boundary line by using the boundary points in the current detection area of the robot comprises: The robot scans the boundary points in the current detection area by using a laser sensor, wherein the distance between the boundary points and the current position of the robot is less than or equal to the scanning distance of the laser sensor; The preset boundary line is fitted by using the boundary points in the current detection area according to a straight line fitting algorithm.

8. The robot map exploration method of claim 3, wherein, The method for executing the map repairing operation comprises: Step 1, after the robot constructs the to-be-optimized map by using the laser point cloud, the robot obtains the pose data of the robot and the laser point cloud in the current detection area from the to-be-optimized map; and then executes step 2; Step 2, the pose data obtained in step 1 is processed according to the digital integration method to convert a mask; and then step 3 is executed; Step 3, the area covered by the mask in the to-be-optimized map in step 1 is converted into a passable area, and then the to-be-optimized map converted into the passable area by the mask is configured as the to-be-optimized map in step A.

9. The robot map exploration method of claim 8, wherein, The step 2 comprises: The pose data obtained in step 1 is processed according to the digital integration method to obtain a template; According to the template, the corresponding empty map area is filled with an algorithm to convert the corresponding empty map area into a mask, and the pixel values of each position point in the area covered by the mask are assigned as a preset value. The corresponding empty map area is composed of position points corresponding to the pose data in the current detection area; the area of the mask is greater than or equal to the area of the corresponding empty map area.

10. The robot map exploration method of claim 9, wherein, The step 3 specifically includes: The mask is used to extract an overlapping map area in the to-be-optimized map, and each position point in the overlapping map area is marked as a passable position point to form a passable area, so as to mark the unknown area in the overlapping map area as a known area, and determine that the area covered by the current detection area in the to-be-optimized map is marked as a known area; Then, the passable area is replaced with the corresponding covered map area in the to-be-optimized map, so that the to-be-optimized map replaced with the corresponding covered map area is updated to the to-be-optimized map in step A.

11. The robot map exploration method of claim 9, wherein, The preset boundary extension line segment and the two side boundaries of the current detection area in the robot walking direction form a triangular area, and the shape of the mask is a triangle. The detection angle of the laser sensor is arranged in front of the robot with the robot walking direction as the central axis.

12. The robot map exploration method of claim 2, wherein, In step D, the method for screening the reachable boundary points according to the passability of the front boundary points searched out in step C includes: The robot first erodes the obstacle points in the to-be-tracked contour line according to the pre-set template image, so that the area occupied by the obstacle points is expanded, wherein the obstacle points are pixel points marked as obstacle-occupied positions, and the expansion radius of the pre-set template image is equal to the body radius of the robot; The robot executes a filling algorithm in the to-be-optimized map along the extension direction of the to-be-tracked contour line, and determines whether there is a front boundary point in the neighborhood of the passable position point currently filled, and if so, sets the front boundary point as a reachable boundary point; wherein the front boundary point filled by the robot using the filling algorithm is connected with the current position of the robot.

13. The robot map exploration method of claim 12, wherein, In step D, the method for sequentially storing the reachable boundary points so that the direction in which the lines between the respective reachable boundary points accessed by the robot extend simulates the direction in which the robot walks along the target contour line includes: The robot starts from the search starting point in the to-be-tracked contour line, searches the to-be-tracked contour line in the preset clock direction, and whenever a point in the to-be-tracked contour line is searched, the searched point is marked as a visited point, and then it is detected whether there is a reachable boundary point in the neighborhood of the visited point, and if so, the reachable boundary point is stored in a linear storage space in the preset clock direction, and the reachable boundary point stored in the linear storage space is configured to be accessed first, so that the order in which the reachable boundary points are read from the linear storage space simulates the order in which the robot walks along the respective points in the to-be-tracked contour line in the process of walking in the preset clock direction; The search starting point in the to-be-tracked contour line includes the intersection point of the preset boundary extension line segment and the target contour line determined in step B.

14. A chip for storing program code, characterized by The program code is for performing the robot map exploration method of any one of claims 1 to 13. The program code is for performing the robot map exploration method of any one of claims 1 to 13.

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