Autonomous mobile robot system, and docking path calculation program and docking path calculation method thereof

Abstract

To solve a problem that a load of hardware and processing required for a positioning process is large in a conventional autonomous mobile robot system.SOLUTION: An autonomous mobile robot system of the present invention has: a marker detection unit 31 in which a marker has a pattern using two colors differing in light reflectance, an autonomous mobile robot reads the pattern of the marker from a reflection intensity of a laser point group obtained from a laser sensor 12, and first marker center coordinates are calculated on coordinates having the autonomous mobile robot 10 as an origin; and a docking path calculation unit 32 that generates second marker center coordinates in which the first marker center coordinates are converted into coordinates based on an odometry origin indicating a control origin in a moving area of an own machine and that calculates, using the second marker center coordinates, goal center coordinates indicating a stop position of the autonomous mobile robot 10 and, as a docking path, a line segment being a movement path having the goal center coordinates as an end point.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an autonomous mobile robot system, and a docking path calculation program and a docking path calculation method thereof, and more particularly to an autonomous mobile robot system having an autonomous mobile robot that performs a docking operation to approach a station provided at a specified position while moving autonomously, and a docking path calculation program and a docking path calculation method thereof. [Background technology]

[0002] The use of autonomous mobile robots that autonomously move within a factory or a logistics warehouse to transport goods is becoming more widespread. Patent Document 1 discloses a technique related to the autonomous mobile robot. The unmanned guided vehicle described in Patent Document 1 is equipped with an image sensor that captures images of objects in the direction of travel, a drive unit that independently controls the drive of multiple wheels, a robot control unit that transmits control commands to the drive unit for autonomous driving based on an environmental map, and a wireless communication unit, and the robot control unit is equipped with a function of constantly updating the environmental map and route based on image information from the image sensor, a function of linking any landmark image having a specific shape or pattern to coordinate information on the environmental map, a first current position estimation function of estimating the current position based on the image information from the image sensor and the environmental map, and a second current position estimation function of estimating the current position based on the coordinate information of the landmark image and the environmental map when the image information from the image sensor includes a landmark image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-205044 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 requires a high-resolution image sensor to recognize landmarks, and requires a large amount of computing power for image processing to recognize landmarks whose shapes are uncertain. Therefore, there are problems in that additional hardware is required to realize the position estimation process using the technology described in Patent Document 1, and the processing load increases.

[0005] The present invention has been made to solve such problems, and aims to eliminate the need for additional hardware required for positioning processing, and to achieve high-precision positioning processing while reducing the processing load. [Means for solving the problem]

[0006] One aspect of the autonomous mobile robot system of the present invention includes a marker indicating a destination, and an autonomous mobile robot that moves autonomously within a predetermined movement area, the marker having a pattern using two colors with different light reflectance, one color used as a background and two or more bands indicated by the other color arranged a predetermined distance apart, and the autonomous mobile robot has a laser sensor that detects objects in the direction of travel of the autonomous mobile robot, a marker detection unit that reads the pattern of the marker from the reflection intensity of a laser point cloud obtained from the laser sensor and calculates a first marker center coordinate on a coordinate system having the autonomous mobile robot as the origin, and a docking path calculation unit that generates second marker center coordinates by converting the first marker center coordinates into coordinates based on an odometry origin indicating a control origin within the autonomous mobile robot's movement area, and uses the second marker center coordinates to calculate goal center coordinates indicating a stopping position of the autonomous mobile robot and a line segment that is a movement path having the goal center coordinates as an end point as a docking path.

[0007] One aspect of the docking path calculation program according to the present invention is a docking path calculation program executed by a calculation unit provided in the autonomous mobile robot or in a location capable of communicating with the autonomous mobile robot, in an autonomous mobile robot system having a marker indicating a destination and an autonomous mobile robot that moves autonomously within a preset moving area and is equipped with a laser sensor to detect objects in the direction of travel of the autonomous mobile robot, the marker using two colors with different light reflectance, having a pattern in which one color is used as a background and two or more bands shown in the other color are arranged at a predetermined distance apart, The docking path calculation program performs a marker detection process in which a marker pattern is read from the reflection intensity of a laser point cloud obtained from a laser sensor, and a first marker center coordinate is calculated on a coordinate system with the autonomous mobile robot as the origin, and a docking path calculation process in which the first marker center coordinate is converted into a coordinate system based on an odometry origin indicating the control origin within the autonomous mobile robot's movement area to generate a second marker center coordinate, and uses the second marker center coordinate to calculate a goal center coordinate indicating a stopping position of the autonomous mobile robot and a line segment that is a movement path with the goal center coordinate as an end point, as a docking path.

[0008] The docking path calculation method of the present invention is a docking path calculation method for an autonomous mobile robot system having a marker indicating a destination, and an autonomous mobile robot that moves autonomously within a predetermined movement area and is equipped with a laser sensor that detects objects in the direction of travel of the autonomous mobile robot, and the marker is arranged using two colors with different light reflectance, with one color used as a background and two or more bands indicated by the other color spaced a predetermined distance apart, and a calculation unit provided within the autonomous mobile robot or at a location capable of communicating with the autonomous mobile robot performs a marker detection process in which a pattern of the marker is read from the reflection intensity of a laser point cloud obtained from the laser sensor, and a first marker center coordinate is calculated on a coordinate system having the autonomous mobile robot as the origin, and a docking path calculation process in which the first marker center coordinate is converted into a coordinate system based on an odometry origin indicating a control origin within the autonomous mobile robot's movement area, and a docking path calculation process is performed using the second marker center coordinate to calculate a goal center coordinate indicating a stopping position of the autonomous mobile robot and a line segment that is a movement path having the goal center coordinate as an end point, as a docking path.

[0009] In the autonomous mobile robot system, its docking path calculation program, and docking path calculation method according to the present invention, a marker having a pattern whose center can be calculated is provided, and the docking path is calculated based on the center of the marker. Effect of the Invention

[0010] According to the present invention, it is possible to calculate a docking path that allows highly accurate position control with a simple configuration and processing. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of an autonomous mobile robot system according to a first embodiment. [Diagram 2] FIG. 1 is a schematic diagram of a marker according to a first embodiment. [Diagram 3] 2 is a block diagram of a docking processing device in the autonomous mobile robot according to the first embodiment. FIG. [Figure 4] 4 is a flowchart illustrating a docking process in the autonomous mobile robot according to the first embodiment. [Diagram 5] 4 is a diagram for explaining a process of converting the marker center coordinates used in the autonomous mobile robot system according to the first embodiment into coordinates based on the odometry origin. FIG. [Figure 6] FIG. 2 is a diagram illustrating a docking route in the autonomous mobile robot system according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In order to clarify the description, the following description and drawings are omitted and simplified as appropriate. In addition, each element shown in the drawings as a functional block performing various processes can be configured in hardware with a CPU (Central Processing Unit), memory, and other circuits, and in software, can be realized by a program loaded into memory. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware alone, software alone, or a combination thereof, and are not limited to any one of them. In addition, the same elements are given the same symbols in each drawing, and duplicated explanations are omitted as necessary.

[0013] Moreover, the above-mentioned program includes a set of instructions (or software code) for making the computer perform one or more functions described in the embodiment when the program is read into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or the tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or the communication medium includes electrical, optical, acoustic, or other forms of propagating signals.

[0014] First embodiment FIG. 1 is a schematic diagram of an autonomous mobile robot system 1 according to the first embodiment. As shown in FIG. 1, the autonomous mobile robot system 1 according to the first embodiment includes an autonomous mobile robot 10 and a station 20. In the autonomous mobile robot system 1, the autonomous mobile robot 10 autonomously moves within a moving area set in a predetermined range, and moves between a destination location installed within the moving area and the station 20. In the autonomous mobile robot system 1, the autonomous mobile robot 10 performs a docking operation to approach the station 20. In this docking operation, high accuracy is required for the relative position between the station 20 and the autonomous mobile robot 10, but in the autonomous mobile robot system 1, a simple configuration and processing for the autonomous mobile robot 10 are realized while maintaining high accuracy in the relative position accuracy between the autonomous mobile robot 10 and the station 20 in the docking operation.

[0015] The autonomous mobile robot 10 is provided with wheels 11 and a laser sensor 12. The autonomous mobile robot 10 moves by running using the wheels. The laser sensor 12 detects objects in the direction of travel of the robot itself. For example, the laser sensor 12 detects objects in the direction of travel of the robot itself by moving a laser back and forth in the left and right directions while shifting its position from top to bottom. At this time, the autonomous mobile robot 10 detects the reflected light of the laser light as a laser point cloud, and recognizes the object based on the brightness of the points included in the laser point cloud. In addition, a control unit (not shown) is built into the autonomous mobile robot 10. The control unit is a unit into which a control board including at least a calculation unit and a memory that realizes the functions of a marker detection unit and a docking path calculation unit described later by a program is built.

[0016] In the autonomous mobile robot system 1, a docking operation is performed in which the autonomous mobile robot 10 approaches the station 20. Here, in the autonomous mobile robot system 1, a marker 21 is provided on the station 20, and the marker 21 is used to calculate a docking path to be used in the docking operation in which the autonomous mobile robot 10 approaches the station 20.

[0017] FIG. 2 shows a schematic diagram of the marker according to the first embodiment. The marker can be created, for example, by printing a black band-shaped portion on a white sheet of A4 size paper. The marker 21 has a pattern using two colors with different light reflectance, one color used as a background and two bands shown in the other color arranged at a predetermined distance apart. The marker 21 further has three white bands, and the black bands and the white bands are arranged alternately. In the example shown in FIG. 2, one color is white and the other color is black, but the one color and the other color may be reversed. The number of black bands may be two or more, and the number of white bands may be three or more.

[0018] From another point of view, the marker 21 has white strip-shaped first regions W1 to W3 and black strip-shaped second regions B1 and B2. The first regions and the second regions are arranged alternately. Specifically, the marker 21 has a pattern in which the first regions W1 and W2 are arranged at both ends of the marker in the left-right direction, and the second regions B1 and B2 sandwich the second region W2. In the example shown in FIG. 2, the marker 21 has a width of the second regions B1 and B2 set to 5 cm, and a width of the first region B2 set to 8 cm. In this way, by defining the width of the second regions B1 and B2 and the distance between the second regions B1 and B2, the marker detection process in the marker detection process described later can be performed with high accuracy and with less processing. In addition, when marker 21 is installed, the vertical stripes that become the second region are long in the vertical direction. By using this vertical stripe pattern, marker 21 and the autonomous mobile robot 10 can be made parallel to each other for marker detection, so that a docking path can be calculated that can control the device position with high precision when the autonomous mobile robot 10 approaches station 20.

[0019] Next, a block diagram of a docking processing device in the autonomous mobile robot 10 according to the embodiment 1 is shown in Fig. 3. The docking processing device shown in Fig. 3 performs only a part of the autonomous movement control processing performed by the autonomous mobile robot 10, is a part of the autonomous movement control device, and is incorporated in the autonomous movement control device.

[0020] The docking processing device shown in FIG. 3 has a laser sensor 12, a marker detection unit 31, a docking path calculation unit 32, a path holding unit 33, a robot control unit 34, and a driving unit 35. Here, the marker detection unit 31, the docking path calculation unit 32, and the robot control unit 34 can be implemented only by hardware, but can also be realized by executing a program in the calculation unit 30. In the following description, the marker detection unit 31, the docking path calculation unit 32, and the path holding unit 33 are realized by executing a docking path calculation program in the calculation unit 30. In addition, the path holding unit 33 is implemented by a memory that is implemented so as to be able to communicate with the calculation unit 30. As this memory, a non-volatile memory such as a flash memory, or a volatile memory such as a DRAM (Dynamic Random Access Memory) can be used. In addition, the marker detection unit 31, the docking path calculation unit 32, the path holding unit 33, and the robot control unit 34 are implemented on a board housed in the control unit of FIG. 1.

[0021] The laser sensor 12 detects an object in the direction of travel of the robot. The marker detection unit 31 reads the pattern of the marker 21 from the reflection intensity of the laser point cloud obtained from the laser sensor 12, and performs a marker detection process to calculate a first marker center coordinate on a coordinate system with the autonomous mobile robot 10 as the origin. The docking path calculation unit 32 generates a second marker center coordinate by converting the first marker center coordinate into a coordinate system with the odometry origin indicating the control origin within the movement area of ​​the robot as a reference, and performs a docking path calculation process to calculate a goal center coordinate indicating the stop position of the autonomous mobile robot and a line segment that is a movement path ending at the goal center coordinate as a docking path using the second marker center coordinate. The path storage unit 33 stores the docking path generated by the docking path calculation unit 32. The robot control unit 34 reads out the docking path stored in the path storage unit 33, and gives a drive command to the drive unit 35 so that the autonomous mobile robot 10 moves along the docking path.

[0022] Here, in the autonomous mobile robot system 1 according to the first embodiment, one of the features is the processing of the marker detection unit 31 and the docking path calculation unit 32, so the operation of the marker detection unit 31 and the docking path calculation unit 32 will be described in detail below.

[0023] Fig. 4 shows a flowchart for explaining the docking process in the autonomous mobile robot 10 according to the first embodiment. The flowchart shown in Fig. 4 includes steps S1 to S17, with steps S1 to S13 being performed by the marker detection unit 31 and steps S14 to S17 being performed by the docking path calculation unit 32. The flowchart shown in Fig. 4 is assumed to be opened when the autonomous mobile robot 10 arrives at a docking position, which is a position determined in advance in the autonomous mobile robot system 1, at which the docking operation is started. This docking start position is assumed to be specified as an area of ​​a certain range where the station 20 and the autonomous mobile robot 10 are in a face-to-face state.

[0024] As shown in FIG. 4, when the autonomous mobile robot 10 according to the first embodiment arrives at the docking position, the autonomous mobile robot 10 starts a docking path calculation process. In this docking path calculation process, the marker detection unit 31 first performs a marker detection process (steps S1 to S13). In the marker detection process, the marker detection unit 31 first acquires a point cloud by laser measurement using the laser sensor 12 (step S1). In the point cloud acquisition process of step S1, the laser sensor 12 makes a laser go back and forth from top to bottom and left to right multiple times to acquire information indicating the presence or absence of an object in front of the autonomous mobile robot 10 and the distance between the autonomous mobile robot 10 and the object from the reflection intensity of each point included in the point cloud. Note that the marker 21 is preferably installed at a position where the distance between the installation position and the object or wall behind it is 5 cm or more. By arranging the marker 21 in this manner, the accuracy of the subsequent marker extraction process can be improved.

[0025] Next, the marker detection unit 31 extracts an image of the front part of the autonomous mobile robot 10 from the reflection intensity of the point cloud obtained in step S1 (step S2). After that, the marker detection unit 31 segments the laser point cloud by regarding it as the same segment if the distance between adjacent points in the measurement sweep order of the laser point cloud is equal to or less than a threshold value (for example, 5 cm). Here, it is necessary that the marker 21 is 5 cm or more away from the background so that the marker 21 and the background do not become the same segment. At this point, in addition to the marker 21, various segments such as long segments such as a long table and short segments such as a person's legs are present.

[0026] Next, the marker detection unit 31 performs a segmentation process to generate a plurality of segments from the laser point cloud, with the range in which the distance between adjacent points is equal to or less than a preset point-to-point distance threshold being regarded as the same segment (step S4). More specifically, in the process of step S4, only the segment with the length of the long side of the marker 21 is left as a marker candidate, and the other segments are removed. At this time, the marker detection unit 31 leaves as a marker candidate a segment whose both end lengths are slightly shorter than the long side of the marker 21 (for example, 25 cm) or more and slightly shorter than the long side of the marker 21 (for example, 40 cm) or less, and removes the other segments. That is, in this example, the range that is equal to or less than the point-to-point distance threshold is a range between 25 cm and 40 cm. Furthermore, as a result of the process of step S3, segments such as a long table and a person's legs are removed. However, since there is a possibility that a plurality of A4-sized marker candidates still remain, the noise removal process of steps S5 and S6 is performed.

[0027] Due to the characteristics of the laser sensor 12, measurement values ​​that differ from the actual values ​​may be obtained where there is a large change in the depth direction, such as the edge of the marker 21, which may have chipped corners. Therefore, in step S5, the marker detection unit 31 performs a process of discarding low-precision measurement values ​​at both ends of the segment in order to estimate the plane of the marker 21 with high accuracy.

[0028] Due to the characteristics of the laser sensor, at boundaries where the reflection intensity changes significantly, for example, the black-white boundary within the marker 21, measurement values ​​that are different from the actual values ​​and protrude forward are obtained. Therefore, in step S6, the marker detection unit 31 removes such abnormal values ​​in order to estimate the plane of the marker 21 with high accuracy. The method of detecting abnormal values ​​here is to determine whether each measurement value within a segment is closer than the average of the two measurement points adjacent to that measurement point by a threshold or more. Then, by performing the noise removal process in steps S5 and S6, the abnormal measurement values ​​within the segment are removed, and as a result, an A4-sized line segment, which is the size of the marker 21, is obtained.

[0029] Next, the marker detection unit 31 extracts, from the segments extracted as segment candidates, the segment closest to the robot center as a marker candidate (step S7).

[0030] Next, the marker detection unit 31 performs a binarization process for the points in the marker candidate, using a reflection threshold value of the reflection intensity as a reference, in which an area where the reflection intensity is equal to or greater than the reflection threshold value is determined as a first area having one color (e.g., a white area) and an area where the reflection intensity is less than the reflection threshold value is determined as a second area having the other color (e.g., a black area) (step S8). More specifically, the marker detection unit 31 uses 1.45 times the weakest reflection intensity as a threshold value for determining whether the points are black or white, and binarizes the points in the marker 21 as follows: a point group having a reflection intensity less than 1.45 times as black, and a point group having a reflection intensity equal to or greater than 1.45 times as white.

[0031] Next, the marker detection unit 31 calculates the center of gravity positions of each of the two black areas in the marker candidate, and if it determines that the distance between the two center of gravity positions is within a preset marker distance range (e.g., 13±2 cm), it determines that the marker candidate is marker 21 (step S9).

[0032] Furthermore, if the marker detection unit 31 determines in step S9 that the marker candidate is not the marker 21, it stops the processes of steps S11 to S13 and continues to use the previous position of the marker 21 (step S10). This previous marker 21 is used in the calculation of the docking path calculation unit 32 when the processes of steps S11 to S13 are not performed.

[0033] Next, the marker detection unit 31 performs line fitting on a plurality of first regions that are arranged in the marker candidate, separated by a second region (step S11). More specifically, the marker detection unit 31 confirms that three or more white regions remain in the marker candidate after removing the black regions, and performs line fitting so that the platform coordinate system (base_link) of the autonomous mobile robot 10 is orthogonal to the point cloud of the white regions. Note that if a line is fitted to the marker 21 measured in the platform coordinate system of the autonomous mobile robot 10, the slope of the line becomes infinite, causing a problem that the calculation result becomes unstable. Therefore, the marker detection unit 31 performs line fitting on the mirror image with (x, y) exchanged, and all subsequent calculations using the line are performed in this mirror image space, thereby stabilizing the calculation result.

[0034] Next, in order to estimate the central position (coordinates) of the marker 21, the marker detection unit 31 calculates the average position of the two second region centroids calculated in step S9, and sets this position as the central position (coordinates) of the second region (step S12).

[0035] Next, the marker detection unit 31 transforms the center coordinates of the two black areas into a mirror image space with (x, y) swapped, and further projects them onto a straight line fitted to the white area of ​​the marker 21. The marker detection unit 31 performs an inverse mirror image transformation by swapping (x, y) of one point on the straight line obtained as a result of projecting the coordinates onto the straight line, and sets the point as the first marker center coordinate. Here, the reason for projecting the center coordinates of the two black areas with (x, y) swapped onto a straight line obtained from the white area of ​​the marker 21 is based on the fact that measurement errors are large in strip-shaped areas such as black areas, and relatively small in wide areas such as white areas.

[0036] Next, the autonomous mobile robot 10 calculates a docking path by providing the first marker center coordinates obtained in step S13 or the previous first marker center coordinates adopted in step S10 to the docking path calculation unit 32. Specifically, the docking path calculation unit 32 first converts the first marker center coordinates into odometry origin coordinates (step S14). More specifically, the first marker center coordinates have variations due to measurement errors of the laser sensor 12. A low-pass filter is effective for removing this variation, but the first marker center coordinates are measured with the center of the autonomous mobile robot 10 as the origin, and change from moment to moment as the autonomous mobile robot 10 moves. Therefore, applying a low-pass filter to the first marker center coordinates causes a time delay problem. Therefore, the docking path calculation unit 32 converts the first marker center coordinates based on the robot center coordinates indicating the center of the autonomous mobile robot 10 as a reference into second marker center coordinates based on the odometry origin as shown in FIG. 5. Since the marker 21 is originally physically fixed, the second marker center coordinates expressed by the odometry origin are not affected by the movement of the robot center coordinates and are expressed as being at a fixed position. Note that the odometry origin is a fixed origin that specifies the entire location within the movement range of the autonomous mobile robot 10, such as the power-on position of the autonomous mobile robot 10.

[0037] Next, the docking path calculation unit 32 applies a low-pass filter to the second marker center coordinates (x, y, yaw) expressed at the odometry origin to remove the variation of the second marker center coordinates due to measurement errors (step S15). By expressing the second marker center coordinates at the odometry origin instead of the robot center, it becomes possible to remove the variation without time delay.

[0038] Next, the docking path calculation unit 32 calculates the goal position expressed by the odometry origin from the relative coordinates between the second marker center coordinates and the goal position (for example, a position for determining completion of the docking operation) (step S16).

[0039] Next, the docking path calculation unit 32 generates a docking path that is a straight path that ends at the goal position and that allows the autonomous mobile robot 10 to reach the goal position by moving forward only (step S17). As a result, the autonomous mobile robot 10 starts a docking operation using this docking path.

[0040] Here, the docking path generated in step S17 will be described with reference to FIG. 6. FIG. 6 is a diagram for explaining the docking path in the transport robot system according to the first embodiment. As shown in FIG. 6, the docking path is composed of a sequence of path points (x, y, yaw) expressed by the odometry origin. The autonomous mobile robot 10 searches for the closest point on the straight path expressed by the odometry origin to the robot center expressed by the odometry origin, and is controlled so that the robot center is on the path by feedback control that makes the error between the two points zero. Also, the robot center approaches the goal position by feedforward control that approaches the goal position.

[0041] As described above, in the autonomous mobile robot system 1 according to the first embodiment, the marker 21 having black bands at a predetermined interval against a white background is provided at a location indicating the docking position. This allows the autonomous mobile robot system 1 to recognize the marker 21 only with the laser sensor 12 originally mounted as an objective sensor on the autonomous mobile robot 10. Also, in the autonomous mobile robot system 1 according to the first embodiment, a marker 21 having a fixed simple pattern is used, so image processing for recognizing the pattern is very simple, and the computing power required for the autonomous mobile robot 10 to recognize the marker 21 can be reduced.

[0042] In addition, in the autonomous mobile robot system 1 according to the first embodiment, since the markers 21 have white regions provided at a distance from each other, the error in the relative position between the first marker center coordinates and the robot center coordinates can be reduced by performing straight line fitting using these three white regions. In other words, in the autonomous mobile robot system 1 according to the first embodiment, the error in the relative position between the autonomous mobile robot 10 and the station 20 when the autonomous mobile robot 10 is docked can be reduced. In one example, it has been experimentally demonstrated that the autonomous mobile robot 10 according to the first embodiment can perform a docking operation with an error equal to or less than half the allowable error range.

[0043] The invention made by the inventor has been specifically described above based on the embodiments, but it goes without saying that the present invention is not limited to the embodiments already described, and various modifications are possible without departing from the gist of the invention. [Explanation of symbols]

[0044] 1 Autonomous Mobile Robot System 10 Autonomous Mobile Robot 11 wheels 12 Laser Sensor 20 Stations 21 Marker 30 Arithmetic section 31 Marker detection unit 32 Docking path calculation section 33 Route Maintenance Unit 34 Robot control unit 35 Drive unit

Claims

1. A marker indicating the destination, An autonomous mobile robot that autonomously moves within a preset movement area, The marker has a pattern using two colors with different light reflectance, in which one color is used as a background and two or more bands shown in the other color are arranged at a predetermined distance apart, The autonomous mobile robot comprises: A laser sensor that detects objects in the direction of the aircraft's movement; a marker detection unit that reads a pattern of a marker from the reflection intensity of the laser point cloud obtained from the laser sensor and calculates a first marker center coordinate on a coordinate system having the autonomous mobile robot as an origin; a docking path calculation unit that generates second marker center coordinates by converting the first marker center coordinates into coordinates based on an odometry origin indicating a control origin within a movement area of ​​the autonomous mobile robot, and calculates, using the second marker center coordinates, goal center coordinates indicating a stopping position of the autonomous mobile robot and a line segment that is a movement path having the goal center coordinates as an end point as a docking path, An autonomous mobile robot system in which the autonomous mobile robot starts detecting the marker by the marker detection unit in response to reaching a preset docking start position.

2. 2. The autonomous mobile robot system according to claim 1, wherein the marker further comprises three or more bands of the one color, the bands of the one color and the bands of the other color being arranged alternately.

3. 3. The autonomous mobile robot system according to claim 1, wherein the marker is installed at a position where the distance between the marker and an object or wall behind the marker is 5 cm or more.

4. The marker detection unit generating a plurality of segments from the laser point cloud, each segment being a range in which the distance between adjacent points is equal to or less than a preset inter-point distance threshold; extracting, as segment candidates, segments whose ends are spaced apart from each other by a distance equal to the width of the marker; extracting, from among the segments extracted as the segment candidates, the segment closest to a center of the autonomous mobile robot as a marker candidate; a binarization process is performed on the point group within the marker candidate, using a reflection threshold of reflection intensity as a criterion, defining an area having a reflection threshold or more as a first area having one of the colors and defining an area having a reflection threshold or less as a second area having the other color; An autonomous mobile robot system according to any one of claims 1 to 3, wherein the center of gravity of each of the second regions in the marker candidate is calculated as a second region center of gravity, and when the distance between the two second region centers of gravity is within a predetermined marker distance range, the second region center of gravity is used to calculate the first marker center coordinates.

5. The autonomous mobile robot system according to claim 4 , wherein the marker detection unit determines the first marker center coordinates already calculated in a previous process as the distance between the second regions in the marker candidates when the distance between the second regions is outside the marker distance range.

6. 6. The autonomous mobile robot system according to claim 1, wherein the docking path is a path along which the autonomous mobile robot advances linearly until it reaches the goal center coordinates.

7. 7. The autonomous mobile robot system according to claim 1, wherein at least one of the marker detection unit and the docking path calculation unit is capable of communicating with the autonomous mobile robot and is provided at a position different from the autonomous mobile robot.

8. In an autonomous mobile robot system having a marker indicating a destination and an autonomous mobile robot that moves autonomously within a preset movement area and is equipped with a laser sensor that detects objects in the direction of travel of the autonomous mobile robot, there is provided a docking path calculation program executed by a calculation unit provided in the autonomous mobile robot or in a location capable of communicating with the autonomous mobile robot, the program comprising: The marker has a pattern using two colors with different light reflectance, with one color used as a background and two or more bands shown in the other color spaced apart by a predetermined distance; The docking path calculation program a marker detection process for reading a pattern of a marker from the reflection intensity of a laser point cloud obtained by a laser sensor and calculating a first marker center coordinate on a coordinate system having the autonomous mobile robot as an origin; generating second marker center coordinates by converting the first marker center coordinates into coordinates based on an odometry origin indicating a control origin within the movement area of ​​the autonomous mobile robot, and performing a docking path calculation process to calculate, using the second marker center coordinates, goal center coordinates indicating a stopping position of the autonomous mobile robot and a line segment that is a movement path having the goal center coordinates as an end point as a docking path; a docking path calculation program that starts detection of the marker by the marker detection unit in response to the autonomous mobile robot reaching a preset docking start position.

9. A docking path calculation method for an autonomous mobile robot system having a marker indicating a destination and an autonomous mobile robot that autonomously moves within a preset movement area and is equipped with a laser sensor that detects objects in the autonomous mobile robot's traveling direction, comprising the steps of: The marker is arranged using two colors with different light reflectance, one color is used as a background and two or more bands shown in the other color are arranged at a predetermined distance apart, A calculation unit provided in the autonomous mobile robot or in a location capable of communicating with the autonomous mobile robot, a marker detection process for reading a pattern of a marker from the reflection intensity of the laser point cloud obtained from the laser sensor and calculating a first marker center coordinate on a coordinate system having the autonomous mobile robot as an origin; generating second marker center coordinates by converting the first marker center coordinates into coordinates based on an odometry origin indicating a control origin within the movement area of ​​the autonomous mobile robot, and performing a docking path calculation process to calculate, using the second marker center coordinates, goal center coordinates indicating a stopping position of the autonomous mobile robot and a line segment that is a movement path having the goal center coordinates as an end point as a docking path; The docking path calculation method includes starting detection of the marker by the marker detection unit in response to the autonomous mobile robot reaching a preset docking start position.

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