System for guiding mobile robot to station

Abstract

A system for guiding a mobile robot to a station according to an embodiment of the present invention comprises: a first surface (11) on which a first marker (21) is formed; a second surface (12) on which a second marker (22) is formed, and which is adjacent to the first surface (11) and forms a first obtuse angle with the first surface (11); and a third surface (12) on which a third marker (23) is formed, and which is adjacent to the first surface (11) and forms a second obtuse angle with the first surface (11), the second surface and the third surface being on opposite sides of the first surface. At least one of the first, second, or third marker (21, 22, 23) is captured by a camera of the mobile robot when the mobile robot enters the station, even if the mobile robot is at an arbitrary position. The mobile robot recognizes and analyzes the first, second, or third marker (21, 22, 23) in the captured image and generates an optimal movement path (P) on the basis of the results of the analysis so that the mobile robot can be aligned in the correct orientation and accurately dock at the station.

Description

A system that guides mobile robots to stations

[0001] The present invention relates to a system for correctly correcting the posture of a mobile robot and guiding the mobile robot to a station when the mobile robot docks with the station.

[0002] In general, mobile robots can be manufactured to perform a purpose function, can be battery powered, and can be equipped with devices to perform the purpose function.

[0003] Battery power is consumed as the mobile robot operates and must be charged to keep the mobile robot operating.

[0004] Additionally, the purpose of the mobile robot is to replenish water for example, in case of fire fighting, or to discharge collected dust and wash mops for cleaning.

[0005] The station enables the mobile robot described above to automatically take the necessary actions to continue performing its intended function.

[0006] Mobile robots can move along preset paths, avoid obstacles and reach their destinations by analyzing information collected through cameras and various sensors, and return to their stations when the remaining battery level reaches a preset value or when action is required to perform the intended function.

[0007] A conventional system for guiding a mobile robot to a station is described with reference to FIGS. 1 and 2. FIGS. 1 and 2 are drawings for explaining a conventional system for guiding a mobile robot to a station.

[0008] The station has a target (10) installed and one marker (20) formed on the side wall of the target (10).

[0009] A marker (20) contains coordinate information. More specifically, when a marker (20) is captured by a camera, the image processing unit of the mobile robot recognizes the marker (20). In image analysis, the marker (20) can be analyzed by marker recognition (30), and the marker recognition (30) can analyze the recognition coordinates (40).

[0010] The recognition coordinates (40) include orientation information of the X-axis (41), Y-axis (42), and Z-axis (43), and the orientation posture of the mobile robot can be estimated based on the orientation information.

[0011] The X-axis (41) is an axis pointing in a direction that penetrates vertically to the reference point of the marker (20), the Y-axis (42) is an axis pointing in a horizontal direction from the reference point of the marker (20), and the Z-axis (43) is an axis pointing in a vertical direction from the reference point of the marker (20).

[0012] Additionally, the distance from the mobile robot to the marker (20) can be estimated using a distance sensor mounted on the mobile robot.

[0013] Mobile robots are equipped with a camera for capturing images, a distance sensor for detecting distances, and an image processing unit for analyzing camera images. The distance sensor may be a sensor that measures the distance to the target.

[0014] When the mobile robot returns to the station, the approximate location coordinates of the station are input and it drives toward those location coordinates.

[0015] When a mobile robot enters a station, it must enter a preset entry posture, which allows necessary actions to be taken by the mobile robot, such as charging power, replacing consumables, or replenishing consumables as described above.

[0016] The mobile robot is autonomous and can enter the station from any location.

[0017] Regardless of the mobile robot's current position, it must be aligned correctly before the distance between the mobile robot and the station (D) is reduced to the specified reference distance. This allows the mobile robot to dock with the station.

[0018] An example of entering a station depending on the area where the mobile robot is located is described with reference to Fig. 2.

[0019] Area 1 (A1) is an area where the mobile robot's camera can capture a marker (20) from almost the front. The mobile robot can clearly recognize and analyze the marker (20) to obtain accurate location information, thereby allowing the mobile robot to align itself in the correct posture within the reference distance (D) and enter the station.

[0020] When the mobile robot is in the first area (A1), the marker (20) can be clearly recognized, and thus the mobile robot can be aligned in the correct posture and enter the station before the reference distance (D).

[0021] The second area (A2) is an area where the mobile robot's camera can take an oblique picture of the marker (20).

[0022] When the mobile robot is in the second area (A2), even if it recognizes the marker (20), there is a problem that the information contained in the marker (20) may not be clearly analyzed, and thus the mobile robot may fail to dock with the station.

[0023] Area 3 (A3) is an area where the mobile robot's camera cannot capture the marker (20).

[0024] When the mobile robot is in the third area (A3), it may not be able to recognize the marker (20), and thus the mobile robot must repeat retreating and wandering until it moves to an area where it can recognize the marker (20), and this process consumes a lot of time and drains the remaining battery power.

[0025] [Prior Art Literature]

[0026] [Patent Document]

[0027] (Patent Document 1) KR 10-2559299 B1

[0028] (Patent Document 2) KR 10-2023-0097356 A

[0029] (Patent Document 3) KR 10-2436960 B1

[0030] (Patent Document 4) KR 10-2023-0117825 A

[0031] (Patent Document 5) KR 10-1828441 B1

[0032] The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide a system that guides a mobile robot to a station by ensuring that the mobile robot is aligned in the correct posture even when the mobile robot approaches the station from an arbitrary position.

[0033] A system for guiding a mobile robot to a station according to an embodiment of the present invention for achieving the above technical task includes: a first surface (11) on which a first marker (21) is formed; a second surface (12) on which a second marker (22) is formed and is adjacent to the first surface (11) and forms a first obtuse angle with the first surface (11); and a third surface (12) on which a third marker (23) is formed and is adjacent to the first surface (11) on the opposite side to the second surface (12) and forms a second obtuse angle with the first surface (11).

[0034] When the mobile robot enters the station, at least one of the first, second, and third markers (21, 22, 23) is captured by the camera of the mobile robot, even if the mobile robot is in any location.

[0035] In addition, the system for guiding a mobile robot to a station according to an embodiment of the present invention may have the first and second obtuse angles of 120 to 135 degrees.

[0036] Specific details of other embodiments are included in the detailed description and drawings.

[0037] A system for guiding a mobile robot to a station according to an embodiment of the present invention recognizes at least one of a plurality of markers when the mobile robot approaches the station, even if the mobile robot is in an arbitrary position, estimates the distance between the mobile robot and the marker, and clearly determines the orientation of the mobile robot, thereby optimizing the movement path of the mobile robot and reducing the time it takes for the mobile robot to dock with the station.

[0038] In particular, the system for guiding a mobile robot to a station according to an embodiment of the present invention can recognize and analyze the first, second, and third markers (21, 22, 23) in an image captured by a camera of the mobile robot, and quickly generate a movement path (P) based on the analysis result, and has the effect of enabling the mobile robot to approach the station while being aligned in the correct posture.

[0039] Figures 1 and 2 are drawings for explaining a system for guiding a conventional mobile robot to a station.

[0040] FIG. 3 and FIG. 4 are drawings for explaining a system for guiding a mobile robot to a station according to an embodiment of the present invention.

[0041] FIG. 5 is a flowchart illustrating the operation of a system for guiding a mobile robot to a station according to an embodiment of the present invention.

[0042] FIG. 6 is an exemplary diagram for explaining the operation of a system for guiding a mobile robot to a station according to an embodiment of the present invention. FIG. 6 (a) is an example of recognizing two markers, FIG. 6 (b) is an example of recognizing three markers, and FIG. 6 (c) is an example of recognizing one marker.

[0043] The advantages and features of the present invention and the method for achieving them will become clear with reference to the embodiments described in detail below together with the attached drawings.

[0044] [Explanation of symbols]

[0045] 10: Target

[0046] 20: Marker 21, 22, 23: 1st, 2nd, 3rd markers

[0047] 30: Marker recognition 31, 32, 33: 1st, 2nd, 3rd marker recognition

[0048] 40: Recognition coordinates 41: X-axis

[0049] 42: Y-axis 43: Z-axis

[0050] 100: Mobile Robot

[0051] D: Reference distance P: Movement path

[0052] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The embodiments described below are provided by way of example to help understand the present invention, and it should be understood that the present invention can be implemented with various modifications different from the embodiments described herein. However, when describing the present invention, if it is determined that a detailed description of a related known function or component may unnecessarily obscure the gist of the present invention, the detailed description and specific illustration thereof will be omitted. In addition, the attached drawings are not drawn to scale to help understand the invention, and the sizes of some components may be exaggerated.

[0053] While terms like "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0054] On the other hand, the terms described below are terms established in consideration of their functions in the present invention, and thus may vary depending on the intention or custom of the manufacturer, and therefore their definitions should be made based on the contents throughout this specification.

[0055] Identical reference numerals throughout the specification refer to identical components.

[0056] First, a system for guiding a mobile robot to a station according to an embodiment of the present invention will be described with reference to FIGS. 3 to 6. FIGS. 3 and 4 are diagrams for explaining a system for guiding a mobile robot to a station according to an embodiment of the present invention. FIG. 5 is a flowchart for explaining the operation of a system for guiding a mobile robot to a station according to an embodiment of the present invention. FIG. 6 is an exemplary diagram for explaining the operation of a system for guiding a mobile robot to a station according to an embodiment of the present invention, in which (a) of FIG. 6 is an example of recognizing two markers, (b) of FIG. 6 is an example of recognizing three markers, and (c) of FIG. 6 is an example of recognizing one marker.

[0057] A system for guiding a mobile robot to a station according to an embodiment of the present invention has at least three faces on a target (10), and a marker is formed on each face.

[0058] More specifically, a target (10) can be placed at the station, and the target (10) can be formed with a first surface (11), a second surface (12), and a third surface (13) as shown in FIGS. 3 and 4.

[0059] The first side (11) is formed with a first marker (21).

[0060] The second surface (12) has a second marker (22) formed thereon and is adjacent to the first surface (11) and forms a first obtuse angle with the first surface (11).

[0061] The third side (13) is formed with a third marker (23) and is adjacent to the first side (11) on the opposite side to the second side (12) and forms a second obtuse angle with the first side (11).

[0062] The above first, second, and third markers (21, 22, and 23) each have their own recognition coordinates (40). In the embodiment of the present invention, three markers are configured, so there are three types of recognition coordinates (40).

[0063] The recognition coordinates (40) are capable of knowing three-dimensional coordinate information, and include direction information of the X-axis (41), Y-axis (42), and Z-axis (43), and the direction posture of the mobile robot can be estimated based on the direction information.

[0064] The X-axis (41) is an axis pointing in a direction that penetrates vertically to the reference point of the marker (20), the Y-axis (42) is an axis pointing in a horizontal direction from the reference point of the marker (20), and the Z-axis (43) is an axis pointing in a vertical direction from the reference point of the marker (20).

[0065] That is, when the camera mounted on the mobile robot (100) photographs the first, second, and third markers (21, 22, 23), the recognition coordinates (40) can be determined by analyzing each of the first, second, and third markers (21, 22, 23) as shown in FIG. 3.

[0066] In this way, the orientation posture of the mobile robot (100) can be estimated based on the angle at which the mobile robot (100) is positioned with respect to the target (10) of the station.

[0067] Additionally, the mobile robot (100) is equipped with a distance sensor, which allows the mobile robot (100) to estimate how far it is from the target (10).

[0068] Alternatively, the distance between the mobile robot (100) and the target (10) can be estimated by analyzing the captured video.

[0069] When the mobile robot (100) enters the station, even if the mobile robot (100) is in any location, at least one of the first, second, and third markers (21, 22, 23) can always be captured by the camera of the mobile robot (100), as shown in FIG. 4.

[0070] Meanwhile, the first and second obtuse angles may be 120 to 135 degrees.

[0071] Referring to Figure 4, the characteristics of each area where the mobile robot is located are described.

[0072] When the mobile robot is in the first area (B1), all of the first, second, and third markers (21, 22, 23) can be photographed, and in this case, the mobile robot (100) can set the movement path (P) to the shortest distance as shown in (b) of FIG. 6, and the adjustment of the driving direction can be minimized.

[0073] In particular, if the X-axis (41) orientation value of the first marker (21) can converge to '0', and the X-axis (41) orientation value of the first marker (21) is '0', it can be understood that the mobile robot (100) docked at the correct position when docking to the station.

[0074] If the above first and second obtuse angles are 120 degrees or more, the mobile robot (100) can accurately recognize all of the first, second, and third markers (21, 22, 23) when it is in the first area (B1).

[0075] When the mobile robot (100) is in the second area (B2), the first and second markers (21, 22) can be recognized by taking pictures of the first and second markers (21, 22), or the first and third markers (21, 23) can be recognized by taking pictures of the first and third markers (21, 23).

[0076] For example, as shown in (a) of FIG. 6, the mobile robot (100) may be in a second area (B2) tilted to one side with respect to the target (10), and in this case, at least two markers may be photographed, and three-dimensional coordinate information may be obtained from each marker in the photographed image.

[0077] From the 3D coordinate information obtained at this time, it is possible to determine whether the mobile robot (100) is tilted to the left or right.

[0078] That is, as shown in (a) of Fig. 6, when the mobile robot (100) is on the left with respect to the target (10), the X-axis (41) and Y-axis (42) of each recognition coordinate (40) have positive (+) values, so that the mobile robot (100) can be aligned by moving to the right so that the X-axis (41) value of the first marker (21) converges to '0', and a movement path (P) can be set.

[0079] On the other hand, if the distance between the mobile robot (100) and the target (10) is closer than the set reference distance (D), the mobile robot (100) can be moved backwards, thereby setting the movement path (P) so that the X-axis (41) value of the first marker (21) converges to '0'.

[0080] When the mobile robot (100) is in the third area (B3), the first marker (21) cannot be recognized, but the second marker (22) or the third marker (23) can be recognized.

[0081] For example, as shown in (c) of FIG. 6, the mobile robot (100) may be excessively tilted to one side with respect to the target (10) and may be in the third area (B3). In this case, at least one marker may be photographed, and three-dimensional coordinate information may be obtained from each marker in the photographed image.

[0082] As explained above, it is possible to determine whether the mobile robot (100) is tilted to the left or right from the obtained three-dimensional coordinate information.

[0083] As shown in (c) of Fig. 6, even if the mobile robot (100) is excessively tilted to the right with respect to the target (10), the mobile robot (100) can recognize the second marker (22). At this time, since the X-axis (41) and Y-axis (42) of the recognition coordinates (40) have negative (-) values, the mobile robot (100) can set a movement path (P) so that the X-axis (41) value of the first marker (21) converges to '0'.

[0084] On the other hand, if the distance between the mobile robot (100) and the target (10) is closer than the set reference distance (D), the mobile robot (100) can be moved backwards, thereby setting the movement path (P) so that the X-axis (41) value of the first marker (21) converges to '0'.

[0085] If the first and second obtuse angles are less than 135 degrees, the mobile robot (100) can accurately recognize the first and second markers (21, 22) or the first and third markers (21, 23) when it is in the second area (B2).

[0086] In addition, if the first and second obtuse angles are less than 135 degrees, the mobile robot (100) can accurately recognize the second marker (22) or the third marker (23) when it is in the third area (B3).

[0087] That is, the system for guiding a mobile robot to a station according to an embodiment of the present invention can recognize at least one marker even if the mobile robot (100) is in an arbitrary position by forming the first and second obtuse angles to be 120 to 135 degrees, and can correct the movement path (P) based on the X-axis (41) among the three-dimensional coordinate information of the recognized markers to correctly align the posture of the mobile robot (100) and generate an optimal movement path (P).

[0088] The mobile robot (100) can perform functions such as charging at a station, replenishing water, or emptying dust, depending on its purpose. Referring to FIG. 5, the description will be made assuming charging.

[0089] Step 1 (S1): The mobile robot (100) is equipped with a camera and collects image data captured by the camera.

[0090] Step 2 (S2): Search for markers in the captured image data. One, two, or three markers may be searched, and the more markers searched, the more likely the mobile robot (100) is to have a correct posture. While the embodiment of the present invention suggests three markers, more markers may be placed on planes at different angles.

[0091] Step 3 (S3): This is the step of recognizing markers from the searched markers. Each marker has its own 3D coordinates and orientation values.

[0092] Step 4 (S4): The attitude angle of the mobile robot (100) is estimated and the distance from each marker to the mobile robot (100) is estimated and processed. The attitude angle can be obtained from the X-axis (41) or the Y-axis (42) or the combination of the X-axis (41) and the Y-axis (42) in three-dimensional coordinates.

[0093] Step 5 (S5): The position of the mobile robot (100) can be estimated based on the distance from the target (10) and the attitude angle formed between the target (10) and the mobile robot (100).

[0094] Step 6 (S6): When the position of the mobile robot (100) with respect to the target (10) is determined, a movement path (P) is generated, and the mobile robot (100) moves along the movement path (P) and its posture is aligned. In particular, as the distance between the target (10) and the mobile robot (100) becomes closer than the set shortest distance (D), the mobile robot (100) is corrected to an optimal and correct posture.

[0095] Step 7 (S7): Once the mobile robot (100) has completed docking with the target (10), it processes the intended function. For example, if the mobile robot (100) is to be charged, the charging terminals on both sides can be turned on to allow charging.

[0096] Check the charging status, and if charging is normal, charging is complete (S8).

[0097] If the charging status is checked and charging is not proceeding normally, it is determined as a charging failure (S9) and the administrator is notified. This notification can be done using known technologies, such as sending a text message or voice message via wireless communication to the control room or administrator.

[0098] Alternatively, when a charging failure (S9) is determined, the mobile robot (100) may attempt docking again after detaching from the station.

[0099] Although the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features thereof.

[0100] Therefore, the embodiments described above should be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0101] A system for guiding a mobile robot to a station according to an embodiment of the present invention can be used to charge or maintain a mobile robot.

Claims

1. A first surface (11) on which a first marker (21) is formed; A second marker (22) is formed and a second surface (12) adjacent to the first surface (11) and forming a first obtuse angle with the first surface (11); and A third marker (23) is formed and includes a third surface (12) that is adjacent to the first surface (11) on the opposite side to the second surface (12) and forms a second obtuse angle with the first surface (11); When the mobile robot enters the station, at least one of the first, second and third markers (21, 22 and 23) is captured by the camera of the mobile robot, even if the mobile robot is in any location; A system for guiding a mobile robot including a station to a station.

2. In paragraph 1, The first and second obtuse angles are between 120 and 135 degrees; A system for guiding a mobile robot featuring a station to a station.

Images