Obstacle recognition method based on multi-point TOF module, chip and robot

Abstract

The application discloses a barrier identification method based on a multi-point TOF module, a chip and a robot. The barrier identification method comprises the following steps: a robot obtains effective distances corresponding to unit regions in a light-receiving surface of a multi-point TOF module, wherein the light-receiving surface of the multi-point TOF module is previously divided into a plurality of unit regions arranged in an array; during the process of the robot walking, barrier identification is performed according to the effective distances corresponding to the unit regions of the highest row and the effective distances corresponding to the unit regions of the middle row, so that a wall surface in front of the robot can be accurately predicted.

Description

Technical Field

[0001] This invention relates to the technical field of TOF module detection, specifically to an obstacle recognition method, chip, and robot based on a multi-point TOF module. Background Technology

[0002] In complex obstacle environments, robotic vacuum cleaners often encounter other large obstacles on the ground. Due to cost considerations, the laser sensors currently used in robotic vacuum cleaners are single-line and cannot detect these types of obstacles. The vision sensors are also generally implemented using a single camera, which cannot perform distance calculations in a timely and accurate manner. Therefore, they cannot accurately distinguish obstacles such as walls. Summary of the Invention

[0003] To address the above problems, this invention provides an obstacle recognition method, chip, and robot based on a multi-point Time-of-Flight (TOF) module. The specific technical solution is as follows: An obstacle recognition method based on a multi-point Time-of-Flight (TOF) module is described, comprising: a robot obtaining the effective distance corresponding to a unit region within the light-receiving surface of the multi-point TOF module, wherein the robot pre-divides multiple unit regions distributed in an array within the light-receiving surface of the multi-point TOF module; during the robot's movement, obstacle recognition is performed based on the effective distances corresponding to the unit regions of the highest row and the middle row; wherein the multi-point TOF module is installed at the front end of the robot's body, and the robot's central axis is perpendicular to the light-receiving surface of the multi-point TOF module.

[0004] Furthermore, the array of multiple unit regions forms a detection region; if the number of rows of unit regions distributed within the detection region is odd, then in the vertical direction, the row of unit regions closest to the center of the detection region is the middle row of unit regions within the detection region, and the robot marks the middle row of unit regions within the detection region as the ranging region; if the number of rows of unit regions distributed within the detection region is even, then in the vertical direction, the row of unit regions closest to the center of the detection region includes the two adjacent middle rows of unit regions within the detection region, and the robot marks one of the two adjacent rows of unit regions as the ranging region.

[0005] Furthermore, if the robot detects a change in the effective distance corresponding to one unit area at the center of the ranging region within a preset distance range during its movement, or detects a change in the effective distance corresponding to two unit areas at the center of the ranging region within a preset distance range, then it is determined that an obstacle exists within the field of view of the multi-point TOF module and that the obstacle is located directly in front of the robot. Wherein, if the number of unit areas included in the ranging region is odd, the effective distance corresponding to one unit area at the center of the ranging region is used to represent the distance between the obstacle and the robot; if the number of unit areas included in the ranging region is even, the average of the effective distances corresponding to the two unit areas at the center of the ranging region is used to represent the distance between the obstacle and the robot.

[0006] Further, the method for obstacle recognition based on the effective distances corresponding to the unit regions of the highest row and the middle row includes: in the vertically upward direction, the robot converts the effective distances corresponding to each unit region in the row of unit regions furthest from the center of the detection area into the height of a first reference point, to represent the height of the obstacle contour points within the field of view of the multi-point TOF module. Each unit region in the row of unit regions furthest from the center of the detection area is configured to correspond to a first reference point, and the effective distance corresponding to each unit region in this row is used to represent the distance between the first reference point corresponding to that unit region and the robot. The highest row of unit regions is the row of unit regions furthest from the center of the detection area in the vertically upward direction. In the vertical direction, the robot converts the effective distances corresponding to the unit regions on both sides of the row of unit regions closest to the center of the detection area into the distance between two corresponding second reference points, to represent the obstacles within the field of view of the multi-point TOF module. The width of the multi-point TOF module is defined as follows: each cell region in the row of cells closest to the center of the detection area is configured to correspond to a second reference point, and the effective distance corresponding to each cell region in the row of cells is used to represent the distance between the second reference point corresponding to the cell region and the robot; wherein, the cell region in the middle row is the row of cells closest to the center of the detection area in the vertical direction; the cell regions on both sides of the row of cells are the leftmost cell region and the rightmost cell region of the row of cells, respectively; during the robot's movement, after the robot determines that there is an obstacle within the field of view of the multi-point TOF module and that the obstacle is located directly in front of the robot, when the robot detects that the minimum, median, or mean height of the first reference point is greater than a preset height threshold, and the distance between the second reference point corresponding to the leftmost cell region and the second reference point corresponding to the rightmost cell region is greater than a preset width threshold, the robot determines that the obstacle within the field of view of the multi-point TOF module is a wall and that the wall is located directly in front of the robot.

[0007] Furthermore, within the detection area, the deflection angle between two adjacent unit areas is a preset fixed angle, representing the angle between the reference point corresponding to the two adjacent unit areas and the line connecting the robot's body center; each unit area is configured to correspond to a reference point, and the effective distance corresponding to each unit area is used to represent the distance between the reference point corresponding to that unit area and the robot, which is obtained by the multi-point TOF module, and the effective distance corresponding to each unit area is represented as the effective distance of the corresponding reference point; the multiple unit areas distributed in the array are uniformly distributed on the light-receiving surface of the multi-point TOF module.

[0008] Furthermore, in the vertically upward direction, the reference point corresponding to each unit area in the row of unit areas furthest from the center of the detection area is the first reference point; in the vertically downward direction, the robot sets the reference point corresponding to the unit area in the same column as the unit area corresponding to the first reference point as the third reference point; the robot records the line connecting the first reference point and the robot's body center as the first ranging line segment, and the line connecting the third reference point and the robot's body center as the second ranging line segment, and the angle formed by the first ranging line segment and the second ranging line segment as the preset pitch angle, so that a first reference point, a third reference point, and the robot's body center determine a triangle; the robot sets the height of the first reference point as the sum of the product of the effective distance of the first reference point and the sine function value of half of the preset pitch angle and the preset reference height; wherein, the preset pitch angle is equal to the product of the difference between the number of rows of unit areas distributed in the detection area and 1 and the preset fixed angle.

[0009] Further, the reference point corresponding to each unit area within the ranging region is the second reference point; the robot denotes the line connecting the second reference point corresponding to the leftmost unit area of ​​the ranging region to the robot's body center as the third ranging line segment, and the line connecting the second reference point corresponding to the rightmost unit area of ​​the ranging region to the robot's body center as the fourth ranging line segment, and the angle formed by the third and fourth ranging line segments as the maximum horizontal detection angle; wherein, the maximum horizontal detection angle is equal to the product of the difference between the number of unit areas distributed within the ranging region and 1 and a preset fixed angle; based on the maximum horizontal detection angle, the length of the third ranging line segment, and the length of the fourth ranging line segment, the distance between the second reference point corresponding to the rightmost unit area within the ranging region and the second reference point corresponding to the leftmost unit area within the ranging region is calculated using trigonometric functions; wherein, the effective distance of the second reference point corresponding to the rightmost unit area within the ranging region is equal to the length of the fourth ranging line segment, and the effective distance of the second reference point corresponding to the leftmost unit area within the ranging region is equal to the length of the third ranging line segment.

[0010] Furthermore, the multi-point TOF module is a TOF sensor that emits light in different directions toward the outside of the robot. The multi-point TOF module also receives modulated light reflected back from the reflection point and projects it onto the light-receiving surface to form projection points. Each unit region contains multiple projection points, and the effective distance corresponding to that unit region is the weighted average of the flight distances of the multiple projection points within that unit region. During the robot's movement, the flight distance of each projection point is updated. The smaller the flight distance of a projection point within the same unit region, the greater its assigned weight; conversely, the larger the flight distance of a projection point within the same unit region, the smaller its assigned weight.

[0011] A chip for storing a program configured to execute the obstacle recognition method.

[0012] A robot is equipped with a main control chip, wherein a multi-point TOF module is installed at the front end of the robot's body, and the robot's central axis is perpendicular to the light-receiving surface of the multi-point TOF module.

[0013] The beneficial technical effect of this invention is that the robot uses the height information calculated from the effective distance corresponding to the highest row cell area in the multi-point TOF module to identify the height of the obstacle, and uses the effective distance corresponding to the middle row cell area to identify the width of the obstacle. Thus, the robot identifies the size characteristics of the obstacle from reference points at various angles in the horizontal and vertical directions of the light-receiving surface of the multi-point TOF module, accurately predicts the wall in front of the robot, that is, obtains the width and height information of the wall in front within the field of view of the TOF module, and also distinguishes walls with longer horizontal contours. This overcomes the problem of distance data error caused by the non-parallel contour lines of a certain parallel wall in the depth image of the TOF module. Attached Figure Description

[0014] Figure 1 This invention discloses an obstacle recognition method based on a multi-point TOF module. Detailed Implementation

[0015] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals are used throughout. The following description, in conjunction with the accompanying drawings, further clarifies the specific implementation of the present invention, making the technical solution and its beneficial effects clearer and more explicit. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. TOF, or Time of Flight, is a method of measuring distance between two points by utilizing the round-trip flight time of a data signal between a pair of transceivers. The principle of TOF is to measure the time it takes for a photon to travel through space. By converting this time into distance, the distance between the TOF camera and the object can be measured. Typically, a TOF camera consists of a transmitting module and a receiving module. Based on the range of the angular distance measured, it can be divided into single-point TOF modules and multi-point TOF modules. The transmitting module can be an emitting element such as an LED or laser, which emits modulated infrared light, for example, at 850nm. After reflection by the object, the reflected infrared light is received by the receiving module. Since both the emitted and received signals are modulated light waves, a TOF camera can calculate the phase difference between the emitted and received signals and convert it to obtain a depth value, which is the depth distance between the TOF camera and the object, i.e., the flight distance of the modulated light.

[0016] To address the technical problems mentioned in the background, this invention discloses an obstacle recognition method based on a multi-point Time-of-Flight (TOF) module. The method is implemented by an autonomous mobile robot, including robots that walk along a planned path, robots that walk close to the edge of obstacles, and robots that move in other ways within an indoor environment. Autonomous mobile robots can be categorized by function, such as sweeping robots, floor scrubbers, and security patrol robots. A multi-point TOF module is installed at the front of the robot, with the robot's central axis perpendicular to the light-receiving surface of the multi-point TOF module. Preferably, the direction of the robot's central axis from the rear to the front of the robot is its walking direction, but it does not necessarily pass through the center of the light-receiving surface of the multi-point TOF module. Compared to infrared sensors and single-point TOF modules, the multi-point TOF module covers a wider angular range, reflecting the distance information of the obstacle's outline more comprehensively from more directions, helping the robot predict whether obstacle avoidance maneuvers are necessary and the initial direction of obstacle avoidance. Specifically, the transmitter of the multi-point TOF module emits multiple sets of modulated light (including infrared light or laser light), and the receiver of the multi-point TOF module obtains multiple photons within the same light-receiving surface, feeding back the distances of multiple locations. This assists the robot in ranging and positioning within a larger field of view, facilitating the determination of wall location information. The multi-point TOF module collects two-dimensional point cloud data of surrounding obstacles and constructs a two-dimensional point cloud map in real time. The robot's internal controller reads the distance information of each location point collected by the multi-point TOF module in real time, and then converts the point cloud coordinates into world coordinates, including converting the X-axis coordinates, Y-axis coordinates, and rotation angle. This is then projected and converted into a two-dimensional grid map that can be used for robot navigation, referred to as a grid map, reflecting the coordinate position information of the walls and other obstacles detected by the mobile robot on the travel plane. The robot is also equipped with inertial sensors, including but not limited to an odometer for measuring walking distance, a collision sensor for detecting collisions with obstacles, and a gyroscope for measuring the body's rotation angle.

[0017] like Figure 1As shown, the obstacle recognition method includes: a robot obtaining the effective distance corresponding to a unit area within the light-receiving surface of a multi-point TOF module, wherein the robot pre-divides multiple unit areas distributed in an array within the light-receiving surface of the multi-point TOF module, specifically configured to uniformly distribute multiple rows and columns of unit areas within the light-receiving surface of the multi-point TOF module; based on this, the robot also forms a detection area from the multiple array-distributed unit areas. Preferably, the detection area within the light-receiving surface of the TOF module is expandable or fixed. Specifically, the center of the light-receiving surface of the multi-point TOF module is the center of the detection area. Preferably, the robot divides the light-receiving surface of the multi-point TOF module into 3 by 3 units with a side length of 20cm, thus forming a 3-row, 3-column unit area with a side length of 20cm, which constitutes the detection area. Then, during the robot's movement, obstacle recognition is performed based on the effective distances corresponding to the highest row of unit areas and the middle row of unit areas. It should be noted that the effective distance for each unit area changes during the robot's movement, and the latest effective distance is used to update the distance within the same unit area. Preferably, the effective distance corresponding to the highest row of unit areas or the topmost unit area is used to predict the height of obstacles within the field of view, and the effective distance corresponding to the middle row of unit areas is used to predict the width of obstacles within the field of view. This also directly obtains the distance between the robot and obstacles in front, thereby determining the area occupied by the corresponding type of obstacle. Since the ranging information from the TOF module (the effective distance corresponding to the unit area processed by weighted average) can make a preliminary judgment on the outline of obstacles, the robot determines the positional distribution characteristics of obstacles by combining the longitudinal height and lateral width dimensions before contacting the outline of an obstacle, and adjusts its direction in time, such as turning around promptly when encountering a long wall during the cleaning process.

[0018] In this embodiment, within the light-receiving surface of the multi-point TOF module, the deflection angle between two adjacent unit regions is a preset reference angle, representing the angle between the reference point corresponding to the two adjacent unit regions and the line connecting the robot's body center. Even if expressed as the angle between the reference point corresponding to the two adjacent unit regions and the line connecting the multi-point TOF module, it can be calculated using trigonometric functions, the effective distance of the reference point, and the robot's body radius. Each unit region is configured to correspond to one reference point. The effective distance corresponding to each unit region is used to represent the distance between the reference point corresponding to that unit region and the robot, or the distance between the reference point corresponding to that unit region and the robot's body center, or the distance between the reference point corresponding to that unit region and the multi-point TOF module. This distance can be measured by the multi-point TOF module and processed... Weighted average processing is used; where the effective distance corresponding to each unit area is represented as the effective distance of the corresponding reference point; the unit areas within the detection area are evenly distributed on the light-receiving surface of the multi-point TOF module; since the multi-point TOF module is installed at the front end of the robot and the light-receiving surface of the multi-point TOF module (equivalent to the imaging plane of the camera) is set perpendicular to the central axis of the robot (the direction of the robot's walking), this embodiment sets the height of the robot's body center relative to the robot's walking plane as a preset reference height, which is a fixed height value. The robot's walking plane and the ground in front of the robot are located in different ground areas. The multi-point TOF module located above the robot's walking plane can detect whether the ground in front of the robot is suspended by the effective distance of the reference point corresponding to the unit area of ​​the relevant row.

[0019] Specifically, within the detection area, in one row of unit areas, the angles formed by the lines connecting the reference points of every two adjacent unit areas to the center of the robot's body are equal. Preferably, the deflection angle between the centers of two adjacent unit areas within a row of unit areas is fixed. In any two adjacent unit areas, the angles formed by the lines connecting the reference points of each unit area to the center of the robot's body are fixed, which can be equivalent to the angles formed by the lines connecting the reflected modulated light back to a reflection point of each unit area to the center of the robot's body being fixed. Therefore, when there are three unit areas within a row of unit areas, the robot, based on knowing the angles formed by the lines connecting two reference points to the center of the robot's body, can deduce the angles formed by the lines connecting the other two reference points to the center of the robot according to the order of the unit areas corresponding to the two reference points within their respective row of unit areas or the order within the detection area, following the arithmetic progression.

[0020] In this embodiment, the multi-point TOF module emits light that travels in different directions toward the outside of the robot. Specifically, the multi-point TOF module emits modulated light and directs it toward obstacles in different directions. The multi-point TOF module also receives the modulated light reflected back from the reflection point and projects it onto the light-receiving surface to form projection points. Multiple projection points exist within each unit region, and the effective distance corresponding to the unit region is the weighted average of the flight distances of the multiple projection points within that unit region. The smaller the flight distance of a projection point within the same unit region, the greater its weight; conversely, the greater the flight distance of a projection point within the same unit region, the smaller its weight. In some embodiments, the robot obtains the effective distance corresponding to a unit region through a multi-point TOF module, and then configures the effective distance corresponding to each unit region to correspond to a reference point, so that the coordinates of the reference point can be calculated through the effective distance corresponding to a unit region. The reference point is used to represent the position point in front of the robot or the position point on both sides, which may be a position point on the surface of an obstacle, i.e., an obstacle outline point. The orientation of the reference point relative to the robot is specifically determined by the viewing angle range of the multi-point TOF module and the installation position of the multi-point TOF module on the robot. The light-receiving surface in the multi-point TOF module is divided into multiple unit regions, one unit region corresponds to one effective distance, and one unit region is also configured to correspond to one reference point. In this embodiment, a reference point represents a valid location point acquired within a unit region. The multi-point TOF module acquires distances to multiple location points within a unit region. This embodiment represents the effective distance corresponding to a unit region as the effective distance of the reference point corresponding to that unit region. Specifically, the effective distance value is determined by the average of the distances acquired from multiple location points within the unit region. It should be noted that each unit region is a light-receiving surface located within the multi-point TOF module. Within the light-receiving surface of the multi-point TOF module, the unit region is the result of dividing the distribution area of ​​photons reflected back from obstacles. Each unit region is the light-receiving area occupied by a set of photons falling on a two-dimensional plane. One reflection point reflects back one photon (originating from multiple sets of infrared modulated light emitted by the multi-point TOF module). Then, combining the installation position characteristics of the multi-point TOF module on the robot, the angle information measured by the gyroscope, and the distribution characteristics of photons within the light-receiving surface, the robot can construct a trigonometric function model using the effective distance of the reference point corresponding to a unit region to calculate the coordinates of that reference point.

[0021] As one embodiment, the light emitted by the multi-point TOF module is directed toward the outside of the robot in different directions. Specifically, it emits multiple sets of modulated light toward reflection points in different directions, with each set of modulated light corresponding to an emission direction, thereby expanding the viewing area compared to a single-point TOF sensor. The multi-point TOF module is also used to receive modulated light reflected back from the reflection point and project it into the light-receiving surface to form a projection point, i.e., a pixel. Multiple projection points exist in the same unit area, forming a pixel array of the light-receiving surface. The multi-point TOF module is installed in front of the robot's body. When the multi-point TOF module emits modulated light in front of the robot, the reflection point is the location point occupied by an obstacle or wall in front of the robot. For example, when the multi-point TOF module is installed on one side of the robot's body, the angle between the center line of the multi-point TOF module and the robot's walking direction is fixed and configured as a rigid installation angle. When the multi-point TOF module emits modulated light to one side of the robot, the reflection point is the location point occupied by an obstacle or wall on one side of the robot. Then, the rigid installation angle determines the angle by which the line connecting the location point and the center of the body or the contour line segment where the location point is located deviates from the robot's walking direction. The modulated light comprises multiple photons, which are particles in the modulated light emitted from the multi-point TOF module. These photons are reflected back to the light-receiving surface within the multi-point TOF module via reflection points, supporting a point cloud point for detection. Since one photon is reflected from a reflection point, multiple photons fall into the same unit region. Each photon projects into a pixel within its corresponding unit region, located at the projection point. In this embodiment, the flight distance of each photon is the flight distance of the projection point it forms. The flight distance of the projection point represents the distance traveled by the modulated light (mainly a single photon) reflected back from the corresponding reflection point, thus representing the depth information of the unit region where the projection point is located. Therefore, the reference point is not necessarily a reflection point. The reference point is actually the result of a weighted average of the reflection points. In some embodiments, a reference point is specifically a location occupied by an obstacle or a specific location on a wall; in this case, the reference point is a reflection point with positioning significance among multiple reflection points.

[0022] Preferably, the robot sets up a detection area within the light-receiving surface of the multi-point TOF module; then, it divides the detection area into multiple uniformly distributed unit areas to achieve array distribution within the light-receiving surface of the multi-point TOF module and cover reference points within different angle ranges. Here, the angle can refer to the angle formed by the line connecting the reference point corresponding to the unit area and the multi-point TOF module relative to the robot's current walking direction, or it can be the angle formed by the line connecting the reference point corresponding to the unit area and the center of the robot body relative to the robot's current walking direction. Specifically, photons reflected from multiple reflection points fall into a rectangular area of ​​the light-receiving surface within the multi-point TOF module. The unit area is a rectangular area of ​​the light-receiving surface within the multi-point TOF module. If this rectangular area is set as a cell, then within the light-receiving surface of the multi-point TOF module, the detection area is arrayed with cells arranged in a 3x3, 4x4, or 8x8 pattern. The reference point corresponding to each cell has a different offset angle relative to the center (optical axis) of the light-receiving surface of the multi-point TOF module in the same clockwise direction. When the detection area is set with the center of the light-receiving surface of the multi-point TOF module, the reference points corresponding to each cell are arrayed with the center of the light-receiving surface of the multi-point TOF module as the axis. Thus, the multi-point TOF module can simultaneously measure distance values ​​in multiple angular directions, and then use the effective distances corresponding to different unit areas to calculate (based on trigonometric function relationships) the dimensional information in the horizontal and vertical directions to identify the approximate outline of the obstacle.

[0023] As one embodiment, multiple rows and columns of unit regions are uniformly distributed within the light-receiving surface of the multi-point TOF module, and the array of multiple unit regions constitutes the detection area. The multiple unit regions are arranged in an array with the center of the detection area as the axis. Specifically, if the number of rows of unit regions distributed within the detection area is odd, then in the vertical direction, the row of unit regions closest to the center of the detection area is the middle row of unit regions within the detection area. The row of unit regions closest to the center of the detection area refers to the row of unit regions whose vertical distance from the center of the detection area is the smallest. The robot marks the middle row of unit regions within the detection area as the ranging area. Provided that the number of unit regions included in the ranging area is odd, the effective distance corresponding to the middle row of unit regions in the ranging area is used to represent the distance between the obstacle and the robot. Furthermore, by constructing a trigonometric function relationship, the row of unit regions closest to the center of the detection area is... The domain becomes the ranging area for measuring the outline size of the obstacle. If the number of rows of unit areas distributed within the detection area is even, then in the vertical direction, the row of unit areas closest to the center of the detection area includes the two adjacent rows of unit areas in the middle of the detection area. The robot marks one row of unit areas in these two adjacent rows as the ranging area. If the number of unit areas included in the ranging area is odd, the effective distance corresponding to one unit area in the middle of the ranging area is used to represent the distance between the obstacle and the robot. If the number of unit areas included in the ranging area is even, the average of the effective distances corresponding to the two unit areas in the middle of the ranging area is used to represent the distance between the obstacle and the robot (it can also be the distance between the obstacle and the center of the robot's body, or the distance between the obstacle and the multi-point TOF module). Furthermore, by constructing a trigonometric function relationship, the outline size of the obstacle can be measured simultaneously using the middle row of unit areas within the detection area.

[0024] If, during its movement, the robot detects that the effective distance change value corresponding to one unit area at the center of the ranging area is within a preset distance range, or detects that the effective distance change value corresponding to two unit areas at the center of the ranging area is within a preset distance range, then it is determined that an obstacle exists within the field of view of the multi-point TOF module and that the obstacle is located directly in front of the robot. Specifically, when the effective distance change value corresponding to one unit area at the center of the ranging area is within a preset distance range, or when the effective distance change value corresponding to two unit areas at the center of the ranging area is within a preset distance range, an obstacle directly in front of the robot can be directly detected. The corresponding change value is determined by the flight distance of the modulated light reflected from the obstacle in front of it. Furthermore, the effective distance change values ​​corresponding to the unit areas on both sides of the ranging area are determined by the robot's... The flight distance of the modulated light reflected from the contours of the obstacles in front is determined by the distance measurement area. The unit areas on both sides of the distance measurement area include the leftmost and rightmost unit areas of the distance measurement area, which together reflect the presence or absence of obstacles directly in front of the robot. When the robot approaches the obstacle, the angle between the reference point corresponding to the leftmost or rightmost unit area of ​​the distance measurement area and the robot's body center and the contour line of the obstacle decreases. The effective distance corresponding to the unit areas on both sides of the distance measurement area decreases. Of course, the effective distance corresponding to the unit area at the middle position of the distance measurement area also decreases, or the effective distance corresponding to the two middle unit areas of the distance measurement area also decreases. When the decrease is within a preset distance range, it is determined that the robot has identified the obstacle. The preset distance range is set to overcome the interference of error data. It describes the experimental value of the change in the flight distance of the modulated light reflected back by the obstacle during the robot's movement, specifically used to determine the effective distance corresponding to the unit area as the distance information fed back by the obstacle. The unit areas on both sides of the ranging area include the unit area set at the leftmost position and the unit area set at the rightmost position of the ranging area. Then, the robot continues to identify whether the distribution area of ​​the obstacle is biased to the left or right relative to the robot based on the effective distance corresponding to the unit area of ​​the corresponding row, so as to adjust the obstacle avoidance mode.

[0025] Preferably, a row of unit regions consists of a continuous row of unit regions arranged horizontally within the light-receiving surface of the multi-point TOF module, filling the corresponding row of the detection area to accommodate the robot's desired walking direction; alternatively, a column of unit regions consists of a continuous column of unit regions arranged vertically within the light-receiving surface of the multi-point TOF module, filling the corresponding column of the detection area to accommodate the obstacle height information required by the robot. Further, when the number of unit regions in a row is even, the two middle unit regions are located on either side of the central axis of the row; when the number of unit regions in a row is odd, except for the middle unit region, the remaining unit regions are located on either side of the central axis of the row. The array of multiple unit regions constitutes the detection area.

[0026] In one embodiment, multiple rows and columns of unit regions are uniformly distributed within the light-receiving surface of the multi-point TOF module. These arrayed unit regions form a detection area. The array of unit regions is arranged with the center of the detection area as its exact center (the very center), the center of the two adjacent unit regions at the very center, or the center of the four neighboring unit regions at the very center as its center. If the number of rows of unit regions within the detection area is odd, then in the vertical direction, the row of unit regions closest to the center of the detection area is the very center row of unit regions within the detection area, and the robot marks this very center row of unit regions as the ranging area. If the number of rows of unit regions within the detection area is even, then in the vertical direction, the row of unit regions closest to the center of the detection area includes the two adjacent rows of unit regions at the very center, and the robot marks one of these two adjacent rows of unit regions as the ranging area. Therefore, the unit region in the middle row is the ranging area. During the robot's movement, the effective distance corresponding to the unit area changes and is updated and saved; this maintains real-time detection and identification of obstacles in the robot's walking direction.

[0027] Preferably, the modulated light reflected by the obstacle is configured to fall into all unit areas within the detection area. The detection area is a rectangular region configured to cover the entire outline of the obstacle within the field of view of the multi-point TOF module. Before the robot detects the presence of an obstacle and begins to rotate, the robot's walking direction is parallel to its central axis, but does not necessarily pass through the center of the ranging area. Preferably, the outline length of the obstacle within the field of view of the multi-point TOF module is related to the corresponding effective distance between the unit areas on both sides of the detection area. The smaller the corresponding effective distance between the unit areas on both sides of the detection area, the smaller the angle between the modulated light emitted by the multi-point TOF module and the outline of the obstacle, and the larger the length of the obstacle's outline calculated using trigonometric functions. Conversely, the larger the corresponding effective distance between the unit areas on both sides of the detection area, the larger the angle between the modulated light emitted by the multi-point TOF module and the outline of the obstacle, and the smaller the length of the obstacle's outline calculated using trigonometric functions.

[0028] In one embodiment, the center of the detection area is located at the center of the light-receiving surface of the multi-point TOF module. Multiple unit regions distributed in the array are uniformly distributed on the light-receiving surface of the multi-point TOF module. That is, the unit regions within the detection area are uniformly distributed on the light-receiving surface of the multi-point TOF module. The unit regions distributed within the detection area are symmetrically arranged about the center of the light-receiving surface of the multi-point TOF module, meaning that multiple rows and columns of unit regions are uniformly distributed within the light-receiving surface of the multi-point TOF module. Specifically, the number of rows and columns of unit regions distributed within the detection area are at least three, to achieve [the desired effect] on the multi-point TOF module. The light-receiving surface of the block covers at least three reference points at different angles in both the horizontal and vertical directions, and the unit regions distributed within the detection area are symmetrically arranged about the center of the light-receiving surface of the multi-point TOF module. The multi-point TOF module is installed along the robot's central axis, its centerline is perpendicular to the light-receiving surface and passes through the center of the detection area, and the robot's current walking direction is parallel to its central axis. Since the robot's current walking direction passes through the center of the detection area, the effective distance corresponding to the unit region located at the very center (the middle position) of the detection area can reflect the distance between the robot and the obstacle directly in front of it. Therefore, the distribution direction characteristics of the obstacle in front can be located using at least the effective distances corresponding to the three unit regions in the middle row.

[0029] As one embodiment, the method for obstacle recognition based on the effective distance corresponding to the cell region of the highest row and the effective distance corresponding to the cell region of the middle row includes: In the vertically upward direction, the robot converts the effective distance of each unit area within the row of units furthest from the center of the detection area into the height of a first reference point, representing the height of the obstacle within the field of view of the multi-point TOF module. Each unit area within this row of units furthest from the center of the detection area is configured to correspond to a first reference point. The effective distance of each unit area within this row represents the distance between the first reference point and the robot, or the distance between the first reference point and the robot's center, or the distance between the first reference point and the multi-point TOF module. In the vertically upward direction, the row of units furthest from the center of the detection area is the top row of units in the detection area. The effective distance of this top row of units, after being converted into a vertical height, represents the effective height of the outline point at the top of the obstacle. In this embodiment, the top row of units is the row of units furthest from the center of the detection area in the vertically upward direction.

[0030] In the vertical direction, the robot converts the effective distances of the unit regions on both sides of the row of unit regions closest to the center of the detection area into the distance between the two corresponding second reference points, to represent the width of the obstacle within the field of view of the multi-point TOF module. Each unit region in the row of unit regions closest to the center of the detection area is configured to correspond to a second reference point, and the effective distance of each unit region in the row of unit regions is used to represent the distance between the second reference point corresponding to the unit region and the robot. In this embodiment, the unit region of the middle row is the row of unit regions closest to the center of the detection area in the vertical direction. The unit regions on both sides of the row of unit regions closest to the center of the detection area include the leftmost unit region and the rightmost unit region of the row of unit regions. The row of unit regions closest to the center of the detection area is the middle row of unit regions in the detection area, or one row of unit regions among the two adjacent middle rows of unit regions in the detection area. Then, the effective distances of the leftmost second reference point and the rightmost second reference point, after being converted into horizontal lengths, represent the effective width of the contour points on both sides of the obstacle.

[0031] During robot movement, after the robot determines, through the aforementioned related embodiments, that there is an obstacle within the field of view of the multi-point TOF module and that the obstacle is located directly in front of the robot, when the robot detects that the minimum, median, or mean (average) height of the first reference point is greater than a preset height threshold, and the distance between the second reference point corresponding to the leftmost unit area and the second reference point corresponding to the rightmost unit area is greater than a preset width threshold, the robot determines that the obstacle within the field of view of the multi-point TOF module is a wall and is located directly in front of the robot. Here, the wall can be a continuous wall formed by connecting reference points with equal effective distances, and can distinguish obstacles of spatial separation type. Preferably, the preset width threshold is greater than the robot's body diameter or multiple times the body diameter to distinguish walls with longer horizontal profile lengths from walls with shorter horizontal profile lengths; the preset height threshold is set to be greater than the height of a door in an indoor environment or the height of a corridor passage across room areas, all of which select representative size information to describe a complete wall profile model. The robot then rotates 180 degrees in place to turn around, avoiding collisions with walls during its movement. If the wall's outline is short, it can choose to walk along the wall; if the wall's outline is long, it can choose to walk perpendicular to the wall after turning around. In this embodiment, the robot uses the effective distance calculated from the highest row of cells in the multi-point TOF module to identify the height of obstacles, and uses the effective distance from the middle row of cells to identify the width of obstacles. This allows the robot to identify the size characteristics of obstacles from various reference points along the horizontal and vertical axes of the illuminated surface of the multi-point TOF module, accurately predicting the wall in front of the robot. Specifically, it acquires the width and height information of the wall in front within the multi-point TOF module's field of view, distinguishing walls with longer horizontal outlines. This overcomes the distance data error caused by the non-parallel outlines of a parallel wall in the depth image of the multi-point TOF module.

[0032] In the above embodiments, each unit region in the row of unit regions furthest from the center of the detection area in the vertically upward direction is configured to correspond to a first reference point, and each unit region in the row of unit regions furthest from the center of the detection area in the vertically downward direction is configured to correspond to a third reference point. The effective distance corresponding to each unit region is used to represent the distance between the reference point corresponding to that unit region and the robot, and the effective distance corresponding to each unit region is represented as the effective distance of the corresponding reference point. For the row of unit regions furthest from the center of the detection area in the vertically downward direction, the distance of the center of this row of unit regions relative to the center of the detection area in the vertically downward direction is greater than the distance of the centers of other row of unit regions in the detection area relative to the center of the detection area in the vertically downward direction, including comparisons of negative values; it can also be understood as the row of unit regions containing the center with the largest distance in the vertically downward direction relative to the center of the detection area among the centers of all row of unit regions vertically below the center of the detection area. In the vertically downward direction, the reference point corresponding to each unit region in the row of unit regions furthest from the center of the detection area can be defined as the third reference point. Generally, for ease of describing the pitch angle, in the vertically downward row of unit regions furthest from the center of the detection area, the robot sets the reference point corresponding to the unit region in the same column as the unit region corresponding to the first reference point as the third reference point. That is, in this embodiment, the unit region corresponding to each third reference point is set to be in the same column as the unit region corresponding to the corresponding first reference point. The center of a row of unit regions is either the center of the middle unit region in that row or the midpoint of the common boundary of the two middle unit regions.

[0033] It should be noted that within the light-receiving surface of the multi-point TOF module, the deflection angle between two adjacent unit areas is a preset reference angle, representing the angle between the reference point corresponding to the two adjacent unit areas and the center of the robot's body. This angle can also be calculated based on trigonometric function principles and the rigid connection between the multi-point TOF module and the robot's body, from the angle between the reference point corresponding to the two adjacent unit areas and the center of the detection area. In the vertically upward direction, each unit area in the row of unit areas furthest from the center of the detection area is configured to correspond to a first reference point. In the vertically downward direction, each unit area in the row of unit areas furthest from the center of the detection area is configured to correspond to a third reference point. The effective distance corresponding to each unit area represents the distance between the reference point corresponding to that unit area and the robot, and the effective distance corresponding to each unit area represents the effective distance of the corresponding reference point.

[0034] In this embodiment, the line connecting the first reference point and the robot's center is denoted as the first ranging line segment, and the line connecting the third reference point and the robot's center is denoted as the second ranging line segment. The angle formed by the first and second ranging line segments is denoted as the preset pitch angle, which is a pitch angle on a vertical plane. This is to ensure that a first reference point, a third reference point, and the robot's center define a triangle on a vertical plane. The unit area corresponding to the first reference point constituting the preset pitch angle and the unit area corresponding to the third reference point constituting the same preset pitch angle are two unit areas in the same column within the detection area; that is, the unit area corresponding to the first reference point constituting a pitch angle and the unit area corresponding to the third reference point constituting the same pitch angle are in the same column. The preset pitch angle is equal to the product of the difference between the number of rows of unit areas distributed within the detection area and 1, and the preset reference angle. The robot sets the height of the first reference point as the sum of the product of the effective distance of the first reference point and the sine function value of half the preset pitch angle, plus the preset reference height. This height is used as the height of obstacles within the field of view of the TOF module. Furthermore, when the robot approaches the obstacle, the effective distances of both the first and third reference points decrease, or the angle between the line connecting the first reference point and the robot's center and the outline of the obstacle decreases, as does the angle between the line connecting the third reference point and the robot's center and the outline of the obstacle. Within the triangle forming the aforementioned horizontal plane, the preset pitch angle increases, thus increasing the calculated height of the first reference point. Specifically, the product of the effective distance of the first reference point and the sine function value of half the preset pitch angle equals the vertical height deviation between the first reference point and the robot's center. In some embodiments, the robot's center and the center of the detection area are considered to be at the same height. Alternatively, the center of the detection area can be set to be located at the center of the light-receiving surface of the TOF module. In this case, the height deviation equals the height difference between the first reference point and the TOF module, or the height difference between the first reference point and the robot's center.

[0035] As one embodiment, the reference point corresponding to each unit area within the ranging area is a second reference point. It should be noted that if the number of rows of unit areas distributed within the detection area is odd, then in the vertical direction, the row of unit areas closest to the center of the detection area is the middle row of unit areas within the detection area, and the robot marks the middle row of unit areas within the detection area as the ranging area. If the number of rows of unit areas distributed within the detection area is even, then in the vertical direction, the row of unit areas closest to the center of the detection area includes the two adjacent middle rows of unit areas within the detection area, and the robot marks one of the two adjacent rows of unit areas as the ranging area. In this embodiment, the robot denotes the line connecting the second reference point corresponding to the leftmost unit area of ​​the ranging region and the robot's center as the third ranging line segment, and the line connecting the second reference point corresponding to the rightmost unit area of ​​the ranging region and the robot's center as the fourth ranging line segment. The angle formed by the third and fourth ranging line segments is denoteed as the maximum horizontal detection angle. A horizontal triangle is then determined with the second reference points corresponding to the leftmost and rightmost unit areas of the ranging region and the robot's center as vertices. The maximum horizontal detection angle is equal to the product of the difference between the number of unit areas distributed within the ranging region and 1, and the preset reference angle. Then, based on the maximum horizontal detection angle, the length of the third ranging segment, and the length of the fourth ranging segment, the distance between the second reference point corresponding to the rightmost unit region and the second reference point corresponding to the leftmost unit region within the ranging area is calculated using trigonometric functions. That is, within the triangle on the horizontal plane, given the lengths of two triangle sides and the angle between them, the length of the third triangle side is calculated using the law of cosines, serving as the width of the obstacle within the field of view of the multi-point TOF module. The effective distance of the second reference point corresponding to the rightmost unit region within the ranging area is equal to the length of the fourth ranging segment, and the effective distance of the second reference point corresponding to the leftmost unit region within the ranging area is equal to the length of the third ranging segment. When the robot approaches the obstacle, the lengths of the fourth and third ranging segments decrease. Therefore, within the triangle forming the horizontal plane, the maximum horizontal detection angle increases, and the calculated distance between the second reference point corresponding to the rightmost unit region and the second reference point corresponding to the leftmost unit region within the ranging area increases.

[0036] In some embodiments, the multi-point TOF module is used to emit modulated light that is directed toward the front of the robot in different directions; the multi-point TOF module is also used to receive the modulated light reflected back from the reflection point and project it onto the light-receiving surface to form a projection point; wherein, there are multiple projection points in each unit area, and the effective distance corresponding to the unit area is the weighted average of the flight distances of each projection point in the unit area, and the flight distance of the projection point can be expressed as the depth value of the corresponding reflection point; the robot uses the weighted average as the distance between the robot and the corresponding reference point, or the distance between the robot's body center and the corresponding reference point, or the distance between the multi-point TOF module and the corresponding reference point, which is not affected by the contour curve variation characteristics of the obstacle surface, wherein, the smaller the flight distance of the projection point in the same unit area, the greater its weight; the larger the flight distance of the projection point in the same unit area, the smaller its weight. Therefore, the weighted average of the flight distances of each projection point within a single unit area can be determined as the robot's maximum obstacle avoidance distance. In this embodiment, a larger weight is assigned to the depth value of the reflection point with a smaller depth value, so that the maximum obstacle avoidance distance calculated by weighting the average is biased towards the smaller depth value (the outline of the obstacle closer to the robot's current position). Conversely, a smaller weight is assigned to the depth value of the reflection point with a larger depth value, so that the maximum obstacle avoidance distance calculated by weighting the average is biased towards the smaller depth value (the outline of the obstacle closer to the robot's current position), thus reducing the safe distance between the robot and the obstacle. However, based on the reasonable allocation of weights, the robot is not prone to colliding with the obstacle. Even if the actual outline is not that close to the robot, the effective distance corresponding to a unit area calculated by weighting the average can prompt the robot to prepare for obstacle avoidance in advance. The smaller the effective distance, the smaller the limitation on the robot's walking distance, which is beneficial for the robot to avoid obstacles in advance.

[0037] This invention also discloses a chip for storing a program configured to execute the obstacle recognition method disclosed in the foregoing embodiments. This chip controls a robot to identify the height of an obstacle using height information calculated from the effective distance corresponding to the highest row of cells in a multi-point Time-of-Flight (TOF) module, and to identify the width of the obstacle using the effective distance corresponding to the middle row of cells. This allows the robot to identify the size characteristics of the obstacle from multiple reference points at different angles along the horizontal and vertical axes of the illuminated surface of the multi-point TOF module, accurately predicting the wall in front of the robot. Specifically, it acquires the width and height information of the wall in front within the TOF module's field of view, and also distinguishes walls with longer horizontal profiles. This overcomes the distance data error problem caused by the non-parallel contour lines of a parallel wall in the depth image of the TOF module.

[0038] A robot is equipped with a main control chip, which is the chip disclosed in the aforementioned embodiments. A multi-point Time-of-Flight (TOF) module is installed at the front end of the robot's body, and the robot's central axis is perpendicular to the light-receiving surface of the multi-point TOF module. The center of the detection area is located at the center of the light-receiving surface of the multi-point TOF module, and the unit areas distributed within the detection area are symmetrically arranged about the center of the light-receiving surface of the multi-point TOF module. The multi-point TOF module is installed along the robot's central axis, and the centerline of the multi-point TOF module is perpendicular to the light-receiving surface of the multi-point TOF module and passes through the center of the detection area. The robot's current walking direction is parallel to the robot's central axis. The number of rows of unit areas distributed within the detection area is at least three, and the number of columns of unit areas distributed within the detection area is at least three, so as to achieve coverage of at least three reference points at different angles in the horizontal and vertical directions of the light-receiving surface of the multi-point TOF module.

[0039] In the description of this specification, the terms "in one embodiment," "preferred," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. Illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. The connection methods linked in the description of this specification have significant effects and practical utility. Through the above description of the structure and principles, those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. Improvements and substitutions based on the present invention using techniques known in the art all fall within the protection scope of the present invention and should be defined by the claims.

Claims

1. An obstacle recognition method based on a multi-point Time-of-Flight (TOF) module, characterized in that, The obstacle recognition method includes: The robot obtains the effective distance corresponding to the unit region within the light-receiving surface of the multi-point TOF module, wherein multiple unit regions distributed in an array are pre-divided within the light-receiving surface of the multi-point TOF module. During the robot's movement, obstacle recognition is performed based on the effective distances corresponding to the unit areas of the highest row and the middle row. The method for obstacle recognition based on the effective distance corresponding to the cell region of the highest row and the effective distance corresponding to the cell region of the middle row includes: In the vertically upward direction, the robot converts the effective distance of each unit region in the row of units furthest from the center of the detection area into the height of the first reference point, so as to represent the height of the obstacle contour points within the field of view of the multi-point TOF module. Each unit region in the row of units furthest from the center of the detection area is configured to correspond to the first reference point, and the effective distance of each unit region in the row of units is used to represent the distance between the first reference point corresponding to the unit region and the robot. The highest row of unit regions is the row of unit regions furthest from the center of the detection area in the vertically upward direction. In the vertical direction, the robot converts the effective distances of the cell regions on both sides of the row of cell regions closest to the center of the detection area into the distance between the two corresponding second reference points, to represent the width of the obstacle within the field of view of the multi-point TOF module. Each cell region in this row of cell regions closest to the center of the detection area is configured to correspond to a second reference point, and the effective distance of each cell region in this row is used to represent the distance between the corresponding second reference point and the robot. The middle row of cell regions is the row of cell regions closest to the center of the detection area in the vertical direction; the cell regions on both sides of this row of cell regions are the leftmost and rightmost cell regions of this row of cell regions, respectively. During the robot's movement, once the robot determines that there is an obstacle within the field of view of the multi-point TOF module and that the obstacle is located directly in front of the robot, when the robot detects that the minimum, median, or average height of the first reference point is greater than a preset height threshold, and the distance between the second reference point corresponding to the leftmost cell region and the second reference point corresponding to the rightmost cell region is greater than a preset width threshold, the robot determines that the obstacle within the field of view of the multi-point TOF module is a wall and that the wall is located directly in front of the robot.

2. The obstacle recognition method according to claim 1, characterized in that, The array consists of multiple unit regions that form the detection area; If the number of rows of unit regions distributed within the detection area is odd, then in the vertical direction, the row of unit regions closest to the center of the detection area is the middle row of unit regions within the detection area, and the robot marks the middle row of unit regions within the detection area as the ranging area; if the number of rows of unit regions distributed within the detection area is even, then in the vertical direction, the row of unit regions closest to the center of the detection area includes the two adjacent middle rows of unit regions within the detection area, and the robot marks one of the two adjacent rows of unit regions as the ranging area.

3. The obstacle recognition method according to claim 2, characterized in that, If the robot detects that the effective distance change value corresponding to one unit area at the middle position of the ranging area is within a preset distance range during the walking process, or detects that the effective distance change value corresponding to two unit areas at the middle position of the ranging area is within a preset distance range, then it is determined that there is an obstacle within the field of view of the multi-point TOF module and that the obstacle is located directly in front of the robot. Where the number of unit regions included in the ranging region is odd, the effective distance corresponding to the unit region at the middle position of the ranging region is used to represent the distance between the obstacle and the robot; where the number of unit regions included in the ranging region is even, the average of the effective distances corresponding to the two unit regions at the middle position of the ranging region is used to represent the distance between the obstacle and the robot.

4. The obstacle recognition method according to claim 3, characterized in that, Within the detection area, the deflection angle between two adjacent unit areas is a preset fixed angle, representing the angle between the reference point corresponding to the two adjacent unit areas and the line connecting the center of the robot's body; each unit area is configured to correspond to a reference point, and the effective distance corresponding to each unit area is used to represent the distance between the reference point corresponding to that unit area and the robot, which is obtained by the multi-point TOF module, and the effective distance corresponding to each unit area is represented as the effective distance of the corresponding reference point; the multiple unit areas distributed in the array are evenly distributed on the light-receiving surface of the multi-point TOF module.

5. The obstacle recognition method according to claim 4, characterized in that, The reference point corresponding to each cell in the row of cells that is furthest from the center of the detection area in the vertically upward direction is the first reference point; In the vertically downward direction, in the row of cells that is furthest from the center of the detection area, the robot sets the reference point corresponding to the cell region in the same column as the cell region corresponding to the first reference point as the third reference point. The robot records the line connecting the first reference point to the center of the robot's body as the first ranging line segment, and the line connecting the third reference point to the center of the robot's body as the second ranging line segment. The angle between the first ranging line segment and the second ranging line segment is recorded as the preset pitch angle, so that a first reference point, a third reference point, and the center of the robot's body determine a triangle. The robot sets the height of the first reference point as the sum of the product of the effective distance of the first reference point and the sine function value of half of the preset pitch angle and the preset reference height. The preset pitch angle is equal to the product of the difference between the number of rows of the unit regions distributed within the detection area and 1, and the preset fixed angle.

6. The obstacle recognition method according to claim 4, characterized in that, The reference point corresponding to each unit area within the ranging area is the second reference point; The robot denotes the line connecting the second reference point corresponding to the leftmost unit area of ​​the ranging region to the center of the robot's body as the third ranging line segment, and the line connecting the second reference point corresponding to the rightmost unit area of ​​the ranging region to the center of the robot's body as the fourth ranging line segment. The angle formed by the third ranging line segment and the fourth ranging line segment is denoteed as the maximum horizontal detection angle. The maximum horizontal detection angle is equal to the product of the difference between the number of unit areas distributed in the ranging region and 1, and a preset fixed angle. Based on the maximum horizontal detection angle, the length of the third ranging segment, and the length of the fourth ranging segment, the distance between the second reference point corresponding to the rightmost unit area and the second reference point corresponding to the leftmost unit area within the ranging region is calculated using trigonometric functions. The effective distance of the second reference point corresponding to the rightmost unit area within the ranging region is equal to the length of the fourth ranging segment, and the effective distance of the second reference point corresponding to the leftmost unit area within the ranging region is equal to the length of the third ranging segment.

7. The obstacle recognition method according to claim 5 or 6, characterized in that, The multi-point TOF module is a TOF sensor. The light emitted by the multi-point TOF module is directed toward the outside of the robot in different directions. The multi-point TOF module is also used to receive the modulated light reflected back from the reflection point and project it into the light-receiving surface to form a projection point. Within each unit area, there are multiple projection points. The effective distance corresponding to this unit area is the weighted average of the flight distances of the multiple projection points within that unit area. During the robot's movement, the flight distance of each projection point is updated. Among them, the smaller the flight distance of the projection points within the same unit area, the greater their configuration weight; the larger the flight distance of the projection points within the same unit area, the smaller their configuration weight.

8. A chip for storing a program, characterized in that, The program is configured to perform the obstacle recognition method according to any one of claims 1 to 7.

9. A robot equipped with a main control chip, characterized in that, The main control chip is the chip described in claim 8, wherein the multi-point TOF module is installed at the front end of the robot's body, and the robot's central axis is perpendicular to the light-receiving surface of the multi-point TOF module.

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