Robot system

Abstract

To provide a robot system capable of precisely carrying a baggage.SOLUTION: In a robot system 1 that carries a baggage 200 to a baggage unloading site 3, a robot 100 includes: a main unit 10 that moves to a space under the baggage 200 so as to lift up the baggage 200; a distance sensor 13 that detects a distance to the baggage 200; a camera 21 that picks up the image of a marker 300; and a support member 20 that supports the camera 21 at a position higher than the main unit 10. The robot is controlled in such a way that, when the robot 100 comes close to the baggage 200, the robot 100 moves to the baggage 200 in accordance with the detection result by the distance sensor 13, and when the robot 100 comes close to the baggage unloading site 3, the robot 100 moves to the baggage unloading site 3 in accordance with the image of the marker 300.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a robot system.

Background Art

[0002] Patent Document 1 discloses a moving body that transports a cart. The moving body in Patent Document 1 is lifting the cart with the moving body main body part entering below the cart.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The moving body in Patent Document 1 includes an acceleration sensor, a speed sensor, or a gyro sensor. These sensors detect the behavior of the moving body. The moving body in Patent Document 1 uses LiDAR or radar to detect the surrounding situation of the detection area. LiDAR detects the distance between the moving body and an object and the direction of the object. However, when approaching the unloading position to lower the cart, there is a risk that the position accuracy will decrease. Therefore, there are cases where the cart cannot be lowered to an appropriate position.

[0005] The present disclosure has been made in view of such problems, and provides a robot system capable of accurately transporting luggage.

Means for Solving the Problems

[0006] A robot system according to one aspect of the present disclosure is a robot system for transporting a load to an unloading location, the robot comprising: a main body that moves under the load to lift the load; a distance sensor that detects the distance to the load; a camera that captures a marker image of a marker formed on the floor surface; a support member attached to the main body and supporting the camera at a position higher than the main body; and a control unit that controls the robot so as the robot approaches the load, it moves the robot to the load according to the detection result of the distance sensor, and as the robot approaches the unloading location, it moves the robot to the unloading location according to the image of the marker. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a robotic system that can transport goods with high precision. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the overall configuration of the robot system. [Figure 2] This is a block diagram showing the robot's control system. [Figure 3] This is a diagram illustrating the process of loading cargo. [Figure 4] This is a diagram illustrating the process of unloading cargo. [Figure 5] This is a schematic diagram to explain the field of view of a camera. [Modes for carrying out the invention]

[0009] Specific embodiments applying this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the following embodiments. Also, for clarity, the following descriptions and drawings have been simplified as appropriate. Some reference numerals and hatching have been omitted to avoid clutter in the drawings.

[0010] The robot system 1 according to this embodiment will be described below with reference to the drawings. Figure 1 is a schematic diagram showing the overall configuration of the robot system. Figure 2 is a control block diagram showing the configuration of the robot 100.

[0011] As shown in Figure 1, the robot system 1 comprises a package 200 and a robot 100 that transports the package 200. The robot 100 is, for example, an autonomous mobile robot. The robot 100 receives instructions to transport the package 200 from a management server (not shown). For example, the robot 100 receives information such as the package to be transported, the loading location 2, and the unloading location 3 from the management server via wireless communication or the like. Then, the robot 100 moves to the loading location 2 and loads the package 200. The robot 100 moves the package 200 to the destination, the unloading location 3. The robot 100 unloads the package 200 at the unloading location 3. In this way, the robot 100 can transport the package 200 from the loading location 2 to the unloading location 3.

[0012] The robot 100 comprises a main body 10, wheels 11, distance sensors 13, and support members 20. The main body 10 is a chassis that rotatably holds the wheels 11. The main body 10 is a transport cart for carrying the load 200. The main body 10 has a rectangular parallelepiped housing.

[0013] As shown in Figure 2, the main unit 10 is equipped with a battery 17, a drive mechanism 16 for the wheels 11, a control unit 30, and the like. Furthermore, the main unit 10 is equipped with a distance sensor 13 and a lifting mechanism 12. The battery 17 supplies power to the drive mechanism 16, camera 21, distance sensor 13, lifting mechanism 12, control unit 30, etc.

[0014] The drive mechanism 16 includes a motor for rotating the wheels 11. For example, the control unit 30 outputs a drive command to the drive mechanism 16, which then drives the left and right wheels 11 independently. This allows the robot 100 to travel on the floor to the loading area 2 and the unloading area 3. The number of wheels 11 may be one or two or more. At least one of the wheels 11 may be an auxiliary wheel.

[0015] At loading area 2, the main body 10 moves beneath the cargo 200 to lift it. For example, the cargo 200 comprises a transported object 205 and legs 201 provided on the underside of the transported object 205. The transported object 205 is supported by the two legs 201. Since both ends of the transported object 205 are supported by the legs 201, a space S is formed directly beneath the transported object 205. The main body 10 is lower than the height of the legs 201. Therefore, the main body 10 can enter the space S directly beneath the transported object 205. Note that the legs 201 may be provided with reflective members 202. The reflective members 202 are such as light-reflecting metal tape.

[0016] The upper part of the main body 10 is provided with a lifting mechanism 12 for loading and unloading cargo 200. The lifting mechanism 12 is a lifting stage that drives in the vertical direction. The lifting mechanism 12 is a lifter that lifts up and lifts down cargo 200 and has a motor and a guide mechanism.

[0017] When the robot 100 loads the cargo 200 at loading area 2, the lifting mechanism 12 rises while the main body 10 is in the space S below the cargo 200. This lifts the cargo 200, and the legs 201 leave the floor. The cargo 200 is then placed on top of the main body 10, and the robot 100 can transport the cargo 200.

[0018] When the robot 100 unloads the package 200, the lifting mechanism 12 descends. As a result, the legs 201 contact the floor surface, and the package 200 is lowered onto the floor surface. When the robot 100 unloads the package 200, it moves to the next loading location 2.

[0019] A distance sensor 13 is mounted on the side surface of the main body 10. The distance sensor 13 is, for example, an optical sensor and measures the distance to the package 200. Note that the distance sensor 13 may be provided on the four side surfaces of the front, rear, left, and right of the main body 10, or may be provided on only some of the side surfaces. The distance sensor 13 has a light source and a photosensor. The distance sensor 13 emits measurement light, for example, in the forward direction of the moving direction. Then, the distance sensor 13 detects the reflected light reflected by the package 200 or the like.

[0020] For example, the distance sensor 13 is a LiDAR (Light Detection And Ranging) or the like. For example, the distance sensor 13 measures the distance to surrounding objects as point cloud data. The distance sensor 13 scans the measurement light to detect the distance to surrounding objects in each direction. The surrounding objects include not only the package 200 but also walls, obstacles, other robots, people, and the like. The distance sensor 13 is preferably a 2D LiDAR. For example, the distance sensor 13 scans laser light at a constant angular interval in the horizontal plane. Point cloud data corresponding to the shape of the package 200 or the like in the horizontal plane is obtained.

[0021] Furthermore, a support member 20 is attached to the main body 10. The support member 20 extends upward from the side surface of the main body 10. The support member 20 has a pole or the like provided along the vertical direction. The support member 20 is arranged so as not to interfere with the package 200 when lifting the package 200. The support member 20 serves as a support column or support rod for supporting the camera 21. The camera 21 is mounted on the upper part of the support member 20. The support member 20 supports the camera 21 at a position higher than the main body 10.

[0022] Camera 21 is positioned at an angle downwards to capture images of the floor surface. Camera 21 is positioned facing forward in the direction of movement. Camera 21 captures images of the marker 300 provided at the unloading area 3. This allows camera 21 to acquire marker images. The marker 300 is a sticker, tape, or sheet attached to the floor surface. Alternatively, the marker 300 may be painted or printed on the floor surface.

[0023] The marker 300 has a pattern that can be recognized by image processing. The marker 300 may be a pattern such as a two-dimensional barcode. Also, if there are multiple unloading areas 3, the marker 300 may be a unique pattern for identifying each unloading area 3. In addition, the unloading area 3 may be provided with a border or the like to prevent users from placing other objects on it. In other words, the unloading area 3 may be an area enclosed by a border or the like.

[0024] The unloading area 3 is usually an empty space with nothing placed in it. It is preferable that the marker 300 is formed inside the unloading area 3. This eliminates the need for extra space to install the marker 300, thus reducing the footprint. Therefore, space can be used efficiently.

[0025] The control unit 30 controls the movement to the loading area 2 and the unloading area 3. Specifically, the control unit 30 includes a CPU 31 (Central Processing Unit), memory 32, and interface unit (I / F) 33, etc. The CPU 31, memory 32, and interface unit 33 are interconnected via a data bus or the like. The control unit 30 may also include a control microcomputer.

[0026] Memory 32 stores control programs, calculation programs, etc., executed by the CPU 31. The CPU 31 performs various control and calculation processes by executing these programs. Furthermore, memory 32 stores control parameters, map data, etc., for autonomous movement. Interface unit 33 handles the input and output of signals to and from the outside. Interface unit 33 receives detection data from the camera 21 and distance sensor 13. Interface unit 33 also outputs control signals and drive commands to the drive mechanism 16 and lifting mechanism 12.

[0027] For example, when the robot 100 receives positional information indicating the coordinates of the loading location 2 and unloading location 3 on the map data, the control unit 30 searches for a path from loading location 2 to unloading location 3. The control unit 30 controls the drive mechanism 16 so that the robot 100 moves autonomously along the path. Since known odometry and the like can be used for autonomous movement, a detailed explanation is omitted. In addition, the control unit 30 performs the following controls to ensure that the robot moves with high positional accuracy around loading location 2 and unloading location 3. The loading and unloading procedure will be explained below with reference to the diagram.

[0028] Using Figure 3, we will explain the control around the loading area 2. Figure 3 is a schematic side view showing the operation during loading. In Figure 3, the upper part shows the state in which the robot 100 is approaching the load 200. In Figure 3, the lower part shows the state in which the lifting mechanism 12 is rising. In other words, the lower part of Figure 3 shows the state in which the main body 10 has moved below the load 200 and the lifting mechanism 12 is lifting up the load 200.

[0029] When the robot 100 approaches the cargo 200, the control unit 30 controls the robot 100 to move towards the cargo 200 according to the detection result of the distance sensor 13. In other words, the control unit 30 controls the drive mechanism 16 so that the robot 100 approaches the cargo 200 according to the distance D detected by the distance sensor 13. The robot 100 gradually approaches the cargo 200 and can enter the space S directly below the cargo 200. In this way, the robot 100 can move to the loading location 2 with high positional accuracy.

[0030] Specifically, while moving to the loading area 2, the control unit 30 performs position control based on the measurement results from the distance sensor 13. The distance sensor 13 measures the distance D from the distance sensor 13 to the load 200. In this way, the relative positional relationship of the load 200 to the robot 100 can be measured. Alternatively, the distance sensor 13 may measure the shape of the load 200 using point cloud data or the like.

[0031] Furthermore, it is preferable that the distance sensor 13 is positioned at the same height as the legs 201. For example, the distance sensor 13 emits measuring light forward in the direction of movement and detects the reflected light reflected by the legs 201 of the load 200. This allows the distance sensor 13 to detect the distance to the legs 201. In addition, the distance sensor 13 can determine the direction to the legs 201 by scanning the measuring light. Thus, the robot 100 can move between the two legs 201.

[0032] If the distance sensor 13 is a 2D LiDAR, the distance sensor 13 can accurately measure the shape and orientation of the legs 201. For example, point cloud data corresponding to the shape of the legs 201 in the horizontal plane can be obtained. The robot 100 can move to a position corresponding to the shape of the legs 201. Therefore, the relative position of the load 200 in the front-back and left-right directions can be accurately detected. Based on the position of the load 200 obtained from the point cloud data, the control unit 30 provides feedback control to the rotation speed and rotation rate of the wheels 11.

[0033] Furthermore, the leg portion 201 is equipped with a reflective member 202. The reflective member 202 is a reflective tape or the like with high light reflectivity. This can increase the amount of reflected light detected by the distance sensor 13. This can improve the detection accuracy of the distance sensor 13. The reflective member 202 is not limited to tape. For example, the leg portion 201 may be painted or printed with a highly reflective material. The leg portion 201 may also be formed from a highly reflective metal material or resin material.

[0034] Once the main body 10 has moved to the space S below the load 200, the lifting mechanism 12 rises. This allows the main body 10 to lift the load 200. In other words, the legs 201 leave the floor surface F. Because the robot 100 moves to the loading area 2 with high positional accuracy, the main body 10 can reliably lift the load 200. Positional deviations in the left-right and front-back directions can be reduced, allowing the main body 10 to lift the load 200 stably.

[0035] Next, the control around the unloading area 3 will be explained using Figure 4. Figure 4 is a schematic side view showing the operation during unloading. Figure 4 shows the state in which the robot 100 is moving towards the unloading area 3. The unloading area 3 is located in front of the wall W. Therefore, the robot 100 moving towards the unloading area 3 is moving closer to the wall W. Also, a marker 300 is formed on the floor surface F at the unloading area 3.

[0036] When the robot 100 approaches the unloading area 3, the control unit 30 controls the robot 100 to move to the unloading area 3 according to the image of the marker 300 captured by the camera 21. In other words, the control unit 30 calculates the relative position of the marker 300 to the robot 100 based on the marker image. The control unit 30 controls the drive mechanism 16 so that the robot 100 approaches the unloading area 3 according to the relative position of the marker 300.

[0037] Specifically, while moving to the unloading area 3, camera 21 images the floor surface F. Camera 21 is positioned facing diagonally downward in front of the robot 100. Therefore, when the marker 300 enters the field of view A of camera 21, camera 21 images the floor surface F including the marker 300. Camera 21 can capture a marker image when the robot 100 is at a position away from the unloading area 3.

[0038] When the camera 21's image includes the marker 300, the control unit 30 performs position control based on the marker image. The control unit 30 identifies the position of the marker 300 in the image by performing image processing. This allows the control unit 30 to accurately detect the relative position of the unloading location 3 to the robot 100. The control unit 30 can accurately detect the position of the unloading location 3 in the left-right and front-back directions. Therefore, based on the position of the marker 300 obtained from the marker image, the control unit 30 provides feedback control for the rotation speed and rotation rate of the wheels 11.

[0039] In this way, the robot 100 can move to the unloading area 3 with high positional accuracy. Furthermore, there is no need to install structures inside or around the unloading area 3 that the distance sensor 13 can use to detect distance. Therefore, space can be used effectively. In particular, the unloading area 3 is often located near a wall W. Since the wall W is usually a plane aligned vertically, it is difficult to determine its position in the left-right direction using LiDAR or the like. By forming markers 300 with a predetermined pattern on the floor surface F, positional accuracy can be improved. Furthermore, since space can be used efficiently, the efficiency of transportation can be improved.

[0040] The camera 21 is fixed to the support member 20 so that it is positioned higher than the main body 10. The camera 21 is mounted on the support member 20 facing diagonally downwards and forward. In this way, the camera 21 can capture a marker image before the robot 100 moves to the unloading area 3. In other words, even if the robot is a certain distance away from the unloading area 3, the marker 300 will be included in the camera 21's field of view. When the camera 21's image includes the marker 300, the control unit 30 controls the position of the robot 100 based on the marker image. Therefore, the control unit 30 can appropriately control the movement of the robot 100.

[0041] Furthermore, when the lifting mechanism 12 descends and lowers the load 200 to the unloading area 3, the robot 100 moves backward. This transports the load 200 to the unloading area. At this time, the control unit 30 controls the movement of the robot 100 based on the detection result of the distance sensor 13. In other words, after the load 200 is lowered, the marker 300 is hidden by the load 200, so the camera 21 cannot image the marker 300. Therefore, the control unit 30 controls the position of the robot 100 according to the distance to the load 200 detected by the distance sensor 13. Similar to the movement control to the loading area 2, the robot 100 moves according to the distance measured by the distance sensor 13. In other words, the robot 100 moves away from the unloading area 3 in the reverse order of approaching the loading area 2. This allows the robot 100 to move out of the space of the load 200. The robot 100 can move away from the unloading area 3 appropriately.

[0042] Figure 5 is a schematic diagram illustrating the field of view A of camera 21. Specifically, Figure 5 schematically shows images P1 and P2 captured by camera 21. Image P1 in Figure 5 shows an image taken while robot 100 is approaching unloading location 3. In image P1, robot 100 is moving upward so that it is approaching wall W. Image P2 shows an image taken while the lifting mechanism 12 is descending. In other words, image P2 shows the state at the time when robot 100 has finished moving to unloading location 3.

[0043] Images P1 and P2 include the marker 300. Images P1 and P2 also include the main body 10 and a portion of the cargo 200. The main body 10 and cargo 200 are visible at the lower edges of images P1 and P2. During the transport of cargo 200, the relative positions of the camera 21, the main body 10, and cargo 200 remain constant, so the positions of the main body 10 and cargo 200 in images P1 and P2 are constant. The camera 21 is set to a field of view A that includes a portion of the front of the main body 10. The camera 21 is mounted on the support member 20, angled slightly downward and forward, so as to slightly include the main body 10. In this way, the position of the marker 300 can be detected with high accuracy.

[0044] Specifically, the control unit 30 counts the number of pixels from the main unit 10 to the marker 300. Based on the number of pixels, the control unit 30 can measure the distance from the main unit 10 to the marker 300. The control unit 30 can convert the number of pixels in the horizontal and vertical directions in images P1 and P2 into distances in the front-to-back and left-to-right directions. Because the distance from the main unit 10 to the marker 300 can be measured accurately, positional accuracy can be improved. The field of view A may include not only the main unit 10 but also a part of the luggage 200. Of course, depending on the mounting position and size of the luggage 200, the main unit 10 may not be visible in the field of view A of the camera 21, and only the luggage 200 may be included. In this case, the distance from the luggage 200 to the marker 300 can be determined according to the number of pixels.

[0045] As shown in Figure 5, the end of the unloading area 3 closest to the robot 100 is designated as the near end NE, and the end of the unloading area 3 furthest from the robot 100 is designated as the far end FE. In Figure 5, since the robot 100 is moving upward, the lower end of the unloading area 3 becomes the near end NE, and the upper end becomes the far end FE.

[0046] It is preferable that the marker 300 is formed at the far end FE of the unloading area 3. This allows the marker 300 to be imaged for a longer period of time, thereby improving positional accuracy. In other words, the camera 21 can image the marker 300 until the end of movement to the unloading area, or even immediately before reaching the unloading area. On the other hand, if the marker 300 is formed at the near end NE, the marker 300 will be hidden by the main body 10 or the cargo 200 during movement. As a result, the camera 21 will be unable to image the marker 300. For these reasons, it is preferable that the marker 300 be formed at the far end FE of the unloading area 3.

[0047] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, this disclosure can be implemented by having a processor such as a CPU (Central Processing Unit) execute a computer program to perform some or all of the control processing in the robot system 1. For example, the control unit 30 can be implemented as a device capable of executing programs, such as the central processing unit of a computer. Various functions can also be implemented by programs. [Explanation of Symbols]

[0048] 1. Robot System 2. Loading location 3. Unloading location 100 robots 10 Main body 11 wheels 12 Lifting mechanism 13. Distance Sensor 20 Support members 21 Cameras 200 pieces of luggage 201 Legs 202 Reflective material 300 markers S space F Floor

Claims

1. A robotic system for transporting cargo to an unloading location, The robot, Wheels and A drive mechanism for driving the aforementioned wheels, A lifting mechanism for raising and lowering cargo, A main body equipped with the aforementioned wheels, the aforementioned drive mechanism, and the aforementioned lifting mechanism, which moves under the load to lift the load, A distance sensor that emits measuring light in the forward direction to detect the distance to the luggage, A camera positioned diagonally downward in the forward direction and capturing images of a marker formed on the floor surface, A support member attached to the main body and supporting the camera at a position higher than the main body, The system includes a control unit that controls the robot so as to move it to the cargo when the robot approaches the cargo, according to the detection result of the distance sensor, and so as to move the robot to the unloading location according to the image of the marker when the robot approaches the unloading location. The camera is installed with a field of view that includes a part of the main body, The control unit detects the relative position of the unloading location to the robot by identifying the position of the marker in the image, and controls the drive mechanism so that the robot approaches the unloading location according to the relative position. The cargo being transported is supported by legs that are higher than the main body. The aforementioned leg portion includes a reflective member that reflects light, A robot system in which the distance sensor is provided on the side of the main body at the height of the legs, and measures the distance by detecting the reflected light reflected by the reflective member.

2. The unloading area is an area enclosed by a frame line, The robot system according to claim 1, wherein the marker is formed on the inside of the unloading area.

3. The unloading area is located in front of the wall, The robot, which is heading towards the unloading location, is moving so as to approach the wall. The robot system according to claim 2, wherein the marker is formed at the end of the unloading area furthest from the robot.

4. The robot system according to any one of claims 1 to 3, wherein the distance sensor is a two-dimensional LiDAR that scans the measurement light in a horizontal plane.

5. The robot system comprises the load having the legs and the transported object, When the robot loads cargo, the lifting mechanism rises while the main body is below the cargo, causing the cargo to be lifted by the main body and the legs to leave the floor. The robot system according to any one of claims 1 to 3, wherein when the robot unloads a load, the lifting mechanism lowers so that the load comes into contact with the floor surface.

Images