Work robot and method for controlling work robot

Abstract

This work robot comprises: a carriage; a manipulator provided at a position offset to one side in a first direction along a horizontal plane with respect to a central portion of a top plate of the carriage; a vision sensor attached to a tip of the manipulator; and a control device. The control device comprises: a route acquisition unit that acquires route information for the carriage; a manipulator control unit that controls the manipulator; a detection unit that detects a deviation amount of the carriage with respect to a route, on the basis of a marker included in an image captured by the vision sensor; and a travel instruction unit that instructs the carriage to correct a travel position or a travel posture of the carriage, on the basis of the deviation amount, and instructs the carriage to enable the vision sensor to capture an image including a marker disposed on one side in the first direction with respect to the carriage.

Description

Working robot and method for controlling working robot

[0001] This application claims priority to Japanese Patent Application No. 2024-148676, filed on August 30, 2024, the contents of which are incorporated herein by reference.

[0002] 2. Description of the Related Art It has been considered to mount a robot (manipulator) on an automated guided vehicle (AGV) and automatically transport the robot to a work position (see, for example, Patent Document 1).

[0003] Patent No. 2680298

[0004] Meanwhile, AGVs equipped with robots travel autonomously using guidance methods such as magnetic guidance and optical guidance. Conventional commercially available AGVs are generally equipped with sensors tailored to the guidance method and various specialized functions for autonomous travel control, making them highly sophisticated and expensive. Therefore, when a commercially available AGV is introduced into a factory, it may include functions that are not used in the factory (such as automatic transport scheduling and map creation functions), which could result in an equipment configuration and cost that are excessive for the intended use.

[0005] Furthermore, if the AGV cannot move precisely to the correct working position, the relative positions of the robot and the workpiece will be misaligned, making it difficult for the robot to move the tool to the correct working point on the workpiece and perform the work, which will reduce the accuracy of the work performed by the robot.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a work robot that can move a work robot with a simple and low-cost configuration, a marker member for a work robot, and a control method for a work robot.

[0007] In order to solve the above problem, a work robot according to the present disclosure comprises: a cart capable of traveling on a floor surface; a manipulator that is disposed at a position offset to one side in a first direction along a horizontal plane from the center of the top plate of the cart and whose tip position and attitude can be arbitrarily changed; a vision sensor attached to the tip of the manipulator and capable of capturing images including markers disposed at predetermined positions on the floor surface; and a control device, wherein the control device comprises: a path acquisition unit that acquires path information for the cart, including the path along which the cart travels and the positions of a plurality of the markers disposed along the path; a manipulator control unit that controls the manipulator to capture images including the markers with the vision sensor; a detection unit that detects the amount of deviation of the cart with respect to the path based on the markers contained in the images captured by the vision sensor; and a travel instruction unit that instructs the cart to correct the traveling position or traveling attitude of the cart based on the amount of deviation, and instructs the cart to change the direction of travel of the cart so that the vision sensor can capture images including the markers disposed on one side of the cart in the first direction.

[0008] A control method for a work robot according to the present disclosure is a control method for a work robot as described above, comprising the steps of: acquiring path information for the cart, including a path along which the cart travels and the positions of a plurality of the markers arranged along the path; capturing an image with the vision sensor that includes the markers arranged along the path; detecting an amount of deviation of the cart with respect to the path based on the markers included in the captured image; and instructing the cart to correct the traveling position or traveling attitude of the cart based on the amount of deviation, wherein in the step of traveling the cart, when capturing an image including the markers with the vision sensor, the direction of travel of the cart is instructed to the cart so that an image including the markers that is arranged on one side of the cart in the first direction can be captured by the vision sensor.

[0009] According to the work robot and the control method for the work robot disclosed herein, the work robot can be moved with a simple and low-cost configuration.

[0010] FIG. 1 is a diagram showing the overall configuration of a robot system according to the present embodiment. FIG. 2 is a diagram showing the work robot according to the present embodiment as viewed from a different direction than FIG. 1. FIG. 3 is a plan view of the work robot according to the present embodiment. FIG. 4 is a block diagram showing the functional configuration of a robot control device and a travel control device according to the present embodiment. FIG. 5 is a diagram showing a state in which the actuator of the work robot according to the present embodiment is folded. FIG. 6 is a flowchart showing an example of travel processing of a cart by the robot system according to the present embodiment. FIG. 7 is a diagram showing an example of route information according to the present embodiment. FIG. 8 is a diagram for explaining the travel processing of the robot system according to the present embodiment. FIG. 9 is a diagram showing an example operation of the work robot along a route. FIG. 10 is a diagram showing an example of the hardware configuration of the robot control device and the travel control device.

[0011] Hereinafter, embodiments for carrying out a working robot system and a control method for a working robot system according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments.

[0012] (Overall Configuration of Working Robot System) Figure 1 shows the overall configuration of a working robot system according to this embodiment. As shown in Figure 1, working robot system 100 comprises a working robot 1 and an operation PC 3. Working robot 1 automatically performs work instructed by an operator in a work space such as a factory or warehouse. Working robot 1 comprises a cart 2, a manipulator 11, a vision sensor 12, and a robot control device 10.

[0013] (Carriage Configuration) FIG. 2 is a view of the work robot according to this embodiment, viewed from a different direction than FIG. 1. FIG. 3 shows a work robot cart 2 according to this embodiment, which is, for example, an automated guided vehicle (AGV). In this embodiment, the cart 2 is formed in a rectangular shape when viewed from above. As shown in FIGS. 1 to 3, the cart 2 has a top plate 2t and side surfaces 2s. The top plate 2t faces upward and may be capable of carrying items to be transported by the work robot 1. The side surfaces 2s extend downward from the four sides of the top plate 2t. As shown in FIG. 1, the cart 2 is equipped with a travel control device 20, a drive unit 21, wheels 23, and a stopper 24.

[0014] As will be described in detail later, the travel control device 20 controls the drive device 21 so that the carriage 2 moves (travels), stops, changes speed, etc. in accordance with travel instructions from the robot control device 10.

[0015] The drive unit 21 is a travel motor that operates the wheels 23 of the bogie 2. In this embodiment, the wheels 23 are Mecanum wheels (registered trademark) having multiple rollers, and the drive unit 21 has one travel motor for each wheel 23. The drive unit 21 changes the combination of wheels 23 to be rotated and the rotation speed and rotation direction of each wheel 23 in accordance with control commands from the travel control device 20. This allows the bogie 2 to move in any direction.

[0016] As shown in Fig. 3 , the bogie 2 mainly moves in a direction along the long side 2a of the top plate 2t, which is rectangular in plan view, by means of multiple wheels 23 (Mecanum wheels). That is, the bogie 2 moves with one of the two short sides 2b, 2c of the top plate 2t, which is rectangular in plan view, facing forward in the direction of travel, and the other facing backward in the direction of travel. In the following description, the main direction of travel of the bogie 2 (the direction along the long side of the top plate 2t) by means of the multiple wheels 23 (Mecanum wheels) may be referred to as the X-axis direction, and the width direction (first direction) of the bogie 2 that intersects the X-axis direction in the horizontal plane and connects the short sides 2b, 2c may be referred to as the Y-axis direction.

[0017] As shown in FIG. 1, the stopper 24 is a device for fixing the carriage 2 so that it does not move after the carriage 2 has moved to a designated position.

[0018] The dolly 2 may further include a travel assistance sensor (not shown). The travel assistance sensor is a sensor for detecting the position and traveling direction of the dolly 2 so that the dolly 2 can travel autonomously when there is no travel instruction from the robot control device 10 (described later). In this embodiment, the travel assistance sensor has a position detection sensor that detects the amount of movement of the dolly 2 in the horizontal direction (X-axis direction and Y-axis direction). The position detection sensor is a sensor that uses the same technology as a so-called optical mouse, and reads the pattern on the floor surface, etc., to detect the amount of movement of the dolly 2 in the X-axis direction and Y-axis direction. The travel assistance sensor may also include a gyrocompass that detects the traveling direction of the dolly 2.

[0019] (Configuration of Manipulator and Vision Sensor) As shown in FIGS. 1 to 3 , the manipulator 11 is mounted on the cart 2. In a plan view, the manipulator 11 is provided at a position offset to one side in the width direction (Y-axis direction) of the cart 2 along a horizontal plane with respect to the center 2z of the top plate 2t of the cart 2. In the present embodiment, the manipulator 11 is provided outward in a plan view of the top plate 2t of the cart 2. In the present embodiment, the work robot 1 has a support base 15 that supports the manipulator 11. The support base 15 is provided so as to protrude outward in a plan view of the top plate 2t of the cart 2. The support base 15 is provided so as to protrude from the upper end of a side surface 2s on one side in the width direction of the cart 2 to one side in the width direction (one side in a first direction).

[0020] The manipulator 11 is provided on a support base 15. The manipulator 11 is an articulated robot arm having a plurality of joints 11j. A base end 11b of the manipulator 11 is fixed to the support base 15. The manipulator 11 is configured by connecting a plurality of arm members 11d rotatably via the joints 11j. The position and posture of the tip end 11a of the manipulator 11 can be arbitrarily changed by rotating each joint. Note that the configuration of the manipulator 11, such as the number of joints 11j of the manipulator 11, is not limited in any way and may be any configuration.

[0021] A tool 13 is detachably attached to the tip 11a of the manipulator 11. The tool 13 is an implement for performing various tasks. Tasks performed by the working robot 1 include, for example, welding, assembly tasks such as screwing and drilling, picking tasks such as grasping and moving parts, finishing, ultrasonic inspection, and visual inspection. A tool 13 appropriate for the task is attached to the tip 11a of the manipulator 11.

[0022] Vision sensor 12 is attached to the tip 11a of manipulator 11. Vision sensor 12 is a camera that captures images of the surroundings of work robot 1. Figure 1 shows an example in which vision sensor 12 has a CCD camera 12A and a 3D camera 12B. Vision sensor 12 is capable of capturing images of landmarks L provided in the area in which work robot 1 travels. In this embodiment, guide lines L1 and markers L2 are provided as the landmarks L.

[0023] (Configuration of guide lines) Guide lines L1 are provided on the floor surface F of the area in which the work robot 1 travels. Guide lines L1 extend in a predetermined direction on the floor surface F to guide the direction in which the work robot 1 moves.

[0024] (Marker Configuration) Markers L2 are provided at predetermined positions on floor surface F. A plurality of markers L2 are provided, for example, at positions that overlap with guide line L1, nearby positions that do not overlap with guide line L1, positions near corners where guide line L1 bends, positions along the path of work robot 1, positions where work robot 1 stops, positions where work robot 1 changes direction of travel, etc. In this embodiment, a plurality of markers L2 are provided at preset intervals in the extension direction of guide line L1, for example.

[0025] The marker L2 includes information about its position on the floor surface F. In this embodiment, the marker L2 is, for example, a QR code (registered trademark).

[0026] (Configuration of robot controller) The robot controller 10 is mounted on the work robot 1. The robot controller 10 controls the operation of each part of the work robot 1. In this embodiment, the robot controller 10 also drives the cart 2 to a designated position. The designated position may be, for example, a work position where the work robot 1 performs work, or a storage position for the work robot 1. The designated position is specified by the operator of the work robot 1 via the operation PC 3.

[0027] (Configuration of the Operating PC) The operating PC 3 is a computer operated by the operator of the work robot 1. The operating PC 3 communicates wirelessly with the work robot 1. The operating PC 3 accepts operations from the operator and instructs the work robot 1 on a specified location that will be the destination and a route to the specified location (passing positions, etc.).

[0028] (Functional Configuration of Robot Control Device) Fig. 4 is a block diagram showing the functional configuration of the robot control device and the travel control device according to this embodiment. As shown in Fig. 4, the robot control device 10 includes a path acquisition unit 101, a sensor information acquisition unit 102, a detection unit 103, a travel instruction unit 104, and a manipulator control unit 105.

[0029] The route acquisition unit 101 acquires route information D1 from the operation PC 3. The route information D1 includes a route Q from the current position of the cart 2 to a designated position, a guide line L1 arranged along the route Q, and the positions of a plurality of markers L2. The route information D1 also includes information indicating on which side of the route Q in the width direction the guide line L1 and each marker L2 are arranged.

[0030] The sensor information acquisition unit 102 acquires the image D2 captured by the vision sensor 12. For example, in this embodiment, the sensor information acquisition unit 102 acquires the image D2 captured by the CCD camera 12A of the vision sensor 12 when the cart 2 is moving.

[0031] The detection unit 103 detects the amount of deviation in the running position and direction of travel (angle) of the trolley 2 relative to the specified route Q based on the guide lines L1 and markers L2 contained in the image captured by the vision sensor 12 (CCD camera 12A).

[0032] The travel instruction unit 104 outputs travel instructions D4 to the bogie 2 (travel control device 20) to instruct the bogie 2 on the travel position, stopping, speed, etc. For example, the travel instruction unit 104 instructs the bogie 2 to control the travel direction (angle) of the bogie 2 based on the travel direction of the bogie 2 detected by the detection unit 103 based on the guide line L1. Furthermore, the travel instruction unit 104 instructs the bogie 2 to correct the travel position and travel direction (angle) of the bogie 2 based on the amount of deviation of the bogie 2 detected by the detection unit 103 based on the marker L2.

[0033] In order to detect the amount of deviation of the dolly 2, the traveling instruction unit 104 instructs the dolly 2 on the traveling position and traveling direction of the dolly 2 so that an image including the guide lines L1 and the markers L2 can be captured by the vision sensor 12. The traveling instruction unit 104 causes the dolly 2 to travel along the route Q, and instructs the dolly 2 to sequentially move to positions where each of the multiple markers L2 arranged along the route Q can be captured by the vision sensor 12.

[0034] Furthermore, the travel instruction unit 104 instructs the dolly 2 to stop traveling when capturing an image including the markers L2 with the vision sensor 12 at a position where each of the multiple markers L2 can be captured. This reduces the influence of vibrations during traveling, and allows the markers L2 to be captured well, compared to when the travel of the dolly 2 is not stopped and images are captured with the vision sensor 12 while the dolly 2 is traveling, and the travel instruction unit 104 causes the dolly 2 to travel along the route Q, and stops the travel of the dolly 2 when images are captured with the vision sensor 12. This causes the dolly 2 to repeatedly travel along the route Q and stop traveling to capture images with the vision sensor 12.

[0035] The work robot 1 is equipped with a manipulator 11 on one side of the carriage 2 in the width direction (first direction). For this reason, when the vision sensor 12 attached to the manipulator 11 photographs the guide lines L1 and markers L2, it is preferable that the guide lines L1 and markers L2 are located on one side of the carriage 2 in the width direction, on the side where the manipulator 11 is provided. The travel instruction unit 104 instructs the carriage 2 on the direction of travel of the carriage 2 so that the vision sensor 12 can photograph an image including the markers L2 located on one side of the carriage 2 in the width direction. In other words, if the guide lines L1 and markers L2 are located on the other side (opposite side) of the traveling carriage 2 in the width direction, the travel instruction unit 104 instructs the carriage 2 to turn and reverse the carriage 2 so that the guide lines L1 and markers L2 are located on one side of the traveling carriage 2 in the width direction. Furthermore, although guide lines L1 and markers L2 are arranged on both sides of the width of the traveling trolley 2, if for some reason it is necessary to photograph the guide lines L1 and markers L2 arranged on the other side of the width, the travel instruction unit 104 instructs the trolley 2 to turn around and reverse the front and rear of the trolley 2.

[0036] The travel instruction unit 104 instructs the cart 2 to turn around when the marker L2 to be photographed by the vision sensor 12 switches from one side in the width direction of the cart 2 to the other side, or from the other side in the width direction of the cart 2 to one side, as the cart 2 travels along the path Q. For example, after photographing one marker L2 with the vision sensor 12, if the next marker L2, which is located ahead in the traveling direction of the path Q, is located on the opposite side in the width direction of the first marker L2 photographed by the vision sensor 12, across the path Q, the cart 2 is turned around to reverse its direction of travel. As a result, the marker L2 to be photographed next will be on the same side in the width direction of the cart 2 as the one side on which the manipulator 11 is provided.

[0037] When the side on which the marker L2 is placed is switched, the travel instruction unit 104 instructs the carriage 2 to pivot on the spot using the plurality of wheels 23 made up of Mecanum wheels, when turning the carriage 2. In other words, the carriage 2 is turned on the spot, rather than changing the direction of the carriage 2 as if steering while traveling along the path Q. This makes it less likely that the manipulator 11 or corners of the carriage 2 will interfere with (crash into) surrounding equipment or other objects when turning the carriage 2.

[0038] When the travel instruction unit 104 turns the carriage 2 in response to the change of the side on which the marker L2 is arranged, the travel instruction unit 104 turns the carriage 2 at a bend Qc (see FIG. 9 ) of the path Q where the traveling direction of the carriage 2 is changed. At the bend Qc, it is easier to secure a larger space than at a straight portion of the path Q, and when the carriage 2 is turned, the manipulator 11 and corners of the carriage 2 are less likely to interfere with (clash with) surrounding equipment and other objects.

[0039] The manipulator control unit 105 controls the manipulator 11 so that the vision sensor 12 and the tool 13 are in any position and orientation. The manipulator control unit 105 controls the manipulator 11 so that the vision sensor 12 is oriented facing downward while the carriage 2 is moving, as shown in FIGS. 1 and 2 . The manipulator control unit 105 controls the manipulator 11 so that the vision sensor 12 captures an image including the marker L2. The manipulator control unit 105 controls the manipulator 11 so that the vision sensor 12 captures an image including the marker L2 at a position where each of the multiple markers L2 can be captured. The manipulator control unit 105 extends the manipulator 11 so that the tip end 11a of the manipulator 11 is separated from the base end 11b of the manipulator 11 when viewed from above, at a position where each of the multiple markers L2 can be captured.

[0040] FIG. 5 is a diagram showing the actuators of the work robot according to this embodiment in a folded state. When traveling the carriage 2 along the path Q, the manipulator control unit 105 folds the manipulator 11 so that the tip 11a of the manipulator 11 approaches the base end 11b of the manipulator 11 when viewed from above, as shown in FIG. 5. In this case, it is preferable to fold the manipulator 11 so that the multiple arm members 11d and the vision sensor 12 constituting the manipulator 11 are positioned as vertically above the base end 11b as possible. This prevents moments and centrifugal forces caused by vibrations generated when the carriage 2 travels from acting excessively on the joints 11j of the manipulator 11, thereby preventing adverse effects on the operation of the manipulator 11 and the occurrence of malfunctions.

[0041] When turning the dolly 2 on the path Q, the manipulator control unit 105 preferably causes the vision sensor 12 to capture an image of a marker L2 located just before the position on the path Q where the dolly 2 is to be turned. This allows the position and attitude of the dolly 2 to be corrected before the turn. Furthermore, the manipulator control unit 105 preferably causes the vision sensor 12 to capture an image of a marker L2 located just after the position on the path Q where the dolly 2 is to be turned. This allows the position and attitude of the dolly 2 to be corrected after the turn, even if the wheels 23 slip on the floor surface F during the turn, for example.

[0042] (Functional Configuration of Travel Control Device) As shown in Fig. 4, the travel control device 20 includes a motor control unit 201. The motor control unit 201 controls the drive unit 21 to move, stop, and change the speed of the carriage 2. When there is no travel instruction from the robot control device 10, the motor control unit 201 may control the drive unit 21 so that the carriage 2 travels independently to a specified position based on sensor values ​​(travel amount and traveling direction of the carriage 2) of a travel assistance sensor (not shown).

[0043] When the cart 2 is moved, there is a possibility that the running position and direction of the cart 2 may deviate from the specified path due to factors such as unevenness of the floor surface of a factory, slippage of the wheels 23 on the floor surface F, or an inability to read the guide lines L1. Therefore, in this embodiment, when the robot control device 10 of the work robot 1 photographs the marker L2 with the vision sensor 12, it detects the amount of deviation of the cart 2 from the path based on the photographed marker L2 and issues a driving instruction to the driving control device 20 of the cart 2 to correct the running position. The motor control unit 201 of the driving control device 20 controls the drive device 21 to adjust the running position of the cart 2 in accordance with the driving instruction from the robot control device 10.

[0044] As described above, the wheels 23 of the bogie 2 in this embodiment are Mecanum wheels. The motor control unit 201 may have a calculation unit 201A for calculating control command values ​​indicating whether or not the travel motor of each wheel 23 is rotating, the direction of rotation, the number of rotations, etc. When the coordinates of a destination are given, for example, the calculation unit 201A calculates control command values ​​for each travel motor for moving the bogie 2 toward the destination coordinates. The motor control unit 201 controls the travel motors based on the control command values ​​calculated by the calculation unit 201A.

[0045] (Carriage travel processing by robot) FIG. 6 is a flowchart showing an example of carriage travel processing by the robot according to this embodiment. FIG. 7 is a diagram showing an example of route information according to this embodiment. FIG. 8 is a diagram for explaining the robot travel processing according to this embodiment. Here, the flow of the carriage 2 travel processing by the robot control device 10 of the work robot 1 will be described with reference to FIGS. 6 to 8.

[0046] The path acquisition unit 101 acquires path information D1 ( FIG. 4 ) from the operation PC 3, which indicates the path from the current position of the cart 2 to a designated position (step S101). The designated position is, for example, the work position of the work robot 1. The designated position and path are input by the operator via the operation PC 3. As shown in FIG. 7 , the path information D1 represents the coordinates (X, Y, Z) of the start position (current position), passing positions, and designated position (destination), as well as the orientation (W, P, R) of the cart 2 at each position.

[0047] When the path information D1 is acquired, the robot control device 10 starts the carriage 2 traveling in accordance with the path information D1 (step S102).

[0048] Here, based on the acquired path information D1, the robot control device 10 recognizes whether the next marker L2, which is located ahead of the current position of the cart 2 in the traveling direction along the path Q, is on one side or the other side of the path Q in the width direction. If the next marker L2 is located on the opposite side of the width direction of the cart 2 from the side on which the manipulator 11 is provided at the current position, the robot control device 10 turns the cart 2 and reverses the traveling direction of the cart 2. Then, the manipulator 11 is positioned on the same side of the width direction of the cart 2 as the next marker L2, and then the cart 2 is caused to travel along the path Q.

[0049] After the carriage 2 starts traveling, the robot control device 10 captures an image using the vision sensor 12 and acquires the captured image D2 (step S103). As shown in Figures 1 and 8, in this embodiment, for example, the work robot 1 captures image D2 with the vision sensor 12 facing vertically downward (toward the floor).

[0050] The detection unit 103 determines whether or not guide lines L1 and markers L2 have been detected as landmarks L from the acquired image D2 (step S104). If guide lines L1 have been detected from the acquired image D2 (step S104: Yes), the detection unit 103 detects the traveling direction of the dolly 2 and the amount of deviation of the dolly 2 in the Y direction based on the detection information D3 of the guide lines L1 (step S105). The detection unit 103 detects the amount of deviation indicating how much the position of the dolly 2 has deviated in the Y direction, for example, based on the position of the guide lines L1 in the image D2. Furthermore, the detection unit 103 detects the amount of deviation indicating how much the traveling direction of the dolly 2 has deviated, for example, based on the angle of the guide lines L1 in the image D2.

[0051] Furthermore, when the detection unit 103 detects the marker L2 from the image D2 (step S104: Yes), the detection unit 103 detects the coordinates (X, Y) and angle (angle R around the Z axis) of the detected position of the marker L2 in the image D2 (step S105). Based on the coordinates and angle of the marker L2, the detection unit 103 detects the amount of deviation that indicates how much the position and traveling direction of the cart 2 are deviated.

[0052] Next, the travel instruction unit 104 outputs a travel instruction D4 to the carriage 2 based on the detected amount of deviation and the travel position so as to reduce the amount of deviation of the carriage 2 (step S106).

[0053] For example, as shown in FIG. 8A, when a deviation in the Y direction from the guide line L1 is detected, the travel instruction unit 104 outputs a travel instruction D4 to correct the position of the bogie 2 in the Y direction. This travel instruction is expressed, for example, by the relative coordinates (X, Y) of the corrected position with respect to the current position of the bogie 2. If the bogie 2 is capable of changing its traveling direction using a steering mechanism, the travel instruction D4 may include a relative angle (R) of the corrected traveling direction with respect to the current traveling direction. Note that the travel instruction unit 104 may output a travel instruction D4 to correct the traveling position of the bogie 2 when the deviation amount is equal to or greater than a preset tolerance. In other words, if the deviation amount is less than the tolerance, it is not necessary to correct the position of the bogie 2.

[0054] 8B, when the travel position of the carriage 2 is detected from the marker L2, the travel instruction unit 104 outputs a travel instruction D4, such as coordinates indicating the next destination of the carriage 2, stopping, or changing the speed, based on the travel position of the carriage 2 and the route information D1. For example, assume that the route information D1 includes a route in which the carriage 2 moves in the X direction and then moves in the Y direction upon reaching a certain work area (area 3). In this case, when the travel instruction unit 104 detects from the reading result of the marker L2 that the carriage 2 has reached this work area (area 3), it outputs a travel instruction D4 specifying the coordinates of the next destination to the carriage 2. Note that when the reading result of the marker L2 includes information indicating "stop," "90-degree turn," or "traveling speed," the travel instruction unit 104 may include an instruction to stop, make a 90-degree turn, change the travel speed (accelerate or decelerate), or the like in the travel instruction D4 according to the reading result. In addition, when stopping the trolley 2, the driving instruction unit 104 may detect the amount of deviation in the detected position of the marker L2 and output a driving instruction D4 to adjust the position and attitude of the trolley 2, and after adjusting the position and attitude of the trolley 2, output a driving instruction D4 indicating stopping.

[0055] Thereafter, the robot controller 10 determines whether the carriage 2 has stopped at the designated position (step S107). For example, if the robot controller 10 has instructed the carriage 2 to stop at the designated position (within the work area that is the destination) in step S105 (step S107; YES), the robot controller 10 stops the carriage 2. On the other hand, if the robot controller 10 has not instructed the carriage 2 to stop at the designated position in step S105 (step S107; NO), the robot controller 10 returns to step S103 and continues the travel process of the carriage 2 (steps S103 to S107).

[0056] If the cart 2 is stopped at the specified position in step S107 (step S107; YES), the work robot 1 reads the marker L2 (upper marker L2a) with the vision sensor 12 (step S108). Based on the information contained in the read marker L2 (QR code), the work robot 1 performs predetermined processing, such as determining its own position or performing an interlock before the next operation.

[0057] (Example of Work Robot Movement Along a Path) Figure 9 is a diagram showing an example of work robot movement along a path. It goes without saying that the path Q shown in Figure 9 and the layout of the area in which path Q is set are merely examples. As shown in Figure 9, the work robot 1 described above aligns the direction of travel of the cart 2 at position P1 so that the manipulator 11 is positioned on the same side of the width of the cart 2 as the marker L2a to be photographed. For example, when the work robot 1 is taken out of a storage location, the direction of travel of the cart 2 is also aligned so that the manipulator 11 is positioned on the same side as the marker L2a to be photographed first.

[0058] Thereafter, the carriage 2 is caused to proceed along the path Q, and markers L2b, L2c, and L2d located on the same side as the manipulator 11 are photographed in sequence, and the traveling position and traveling posture of the carriage 2 are corrected. Of these, at position P2 where marker L2c is located, the traveling direction of the carriage 2 is changed so that the carriage 2 turns right. The carriage 2 photographs marker L2c on the inside of the path Q where the traveling direction is changed, and the traveling position and traveling posture are corrected. At this time, the carriage 2 is pivoted at a bend Qc1 of the path Q. Furthermore, it is preferable to photograph marker L2c before and after the carriage 2 turns, and correct the traveling position and traveling posture.

[0059] At position P3 where marker L2d is located, the marker L2d is photographed and the traveling position and traveling posture are corrected, and then the carriage 2 heads along the path Q to a position where the next marker L2e can be photographed. At the current position (position P3), the next marker L2e is located on the opposite side in the width direction of the carriage 2 from the side where the manipulator 11 is located (the right side when facing the traveling direction in the example of FIG. 9 ). Therefore, when the traveling direction of the carriage 2 is changed so that the carriage 2 turns right, the carriage 2 is turned around and the front and rear of the carriage 2 are swapped. At this time, the carriage 2 is pivoted at position P4 of a bend Qc2 of the path Q. After the carriage 2 has turned, the marker L2e is photographed and the traveling position and traveling posture are corrected. At this time, if the marker L2e is far away from the trolley 2 in the width direction of the trolley 2 after turning, the trolley 2 may be translated in the width direction using the wheel 23 consisting of a Mecanum wheel, so that the trolley 2 approaches the marker L2e or the guide line L1.

[0060] Thereafter, the carriage 2 is further advanced along the path Q, and markers L2f, L2g, and L2h, which are provided on the same side of the carriage 2 as the manipulator 11 in the width direction, are sequentially photographed, and the running position and running posture of the carriage 2 are corrected.

[0061] (Operations and Effects) As described above, with the working robot 1 according to this embodiment, the carriage 2 is guided using the vision sensor 12 attached to the manipulator 11, eliminating the need for a separate mechanism for guiding the carriage 2. This allows the carriage 2 to be constructed with minimal equipment and at minimal cost, while also allowing the carriage 2 to move accurately along the path Q. As a result, the working robot 1 can be moved with a simple, low-cost configuration. Furthermore, the manipulator 11 of the working robot 1 is located offset to one side of the width direction (first direction) of the tabletop 2t along the horizontal plane from the center 2z of the tabletop 2t. Therefore, compared to a case where the manipulator 11 is located on the center 2z of the tabletop 2t, the reach of the tip 11a of the manipulator 11 to one side of the tabletop 2t in the first direction is wider. Therefore, even if the marker L2 is separated from the path Q of the carriage 2 in a direction intersecting the extension direction of the path Q, the vision sensor 12 can easily detect the marker L2. As a result, the degree of freedom in the installation position of the marker L2 is increased. Furthermore, the dolly 2 is moved so that an image including the marker L2 placed on one side in the first direction of the dolly 2 can be captured by the vision sensor 12. This makes it easier to capture the marker L2 using the manipulator 11 provided at a position offset to one side in the first direction from the center 2z of the top plate 2t of the dolly 2. Furthermore, since the amount of movement of the manipulator 11 to one side in the first direction when capturing the marker L2 is small, the time required for the operation of the manipulator 11 is shortened, and the marker L2 can be captured efficiently.

[0062] The work robot 1 also sequentially moves the carriage 2 to positions where it can photograph each of the multiple markers L2 arranged along the path Q, and causes the vision sensor 12 to capture an image including the markers L2. This allows the carriage 2 to move along the path Q with high accuracy while correcting the running position and running posture of the carriage 2 as it moves along the path Q.

[0063] Furthermore, when the next marker L2 placed along the path Q is located on the opposite side of the path Q from one marker L2 photographed by the vision sensor 12, the work robot 1 turns the traveling direction of the cart 2 so that one side of the first direction of the cart 2 is on the same side as the next marker L2 with respect to the path Q. This makes it possible to successfully photograph the next marker L2.

[0064] Furthermore, the working robot 1 turns the cart 2 at the bend Qc of the path Q so that the manipulator 11 is on the same side as the next marker L2 with respect to the path Q. This makes it possible to turn the cart 2 at the bend Qc of the path Q where the direction of travel of the cart 2 changes, and to prevent the cart 2 from turning in a straight line along the path Q. This makes it possible to prevent part of the working robot 1 from colliding with objects around the path Q when turning the cart 2.

[0065] Furthermore, the manipulator control unit 105 causes the vision sensor 12 to capture an image of the marker L2 located immediately before the position on the path Q where the carriage 2 is to be turned around. In this way, by capturing an image of the marker L2 located immediately before the position on the path Q where the carriage 2 is to be turned around, the running position and running posture of the carriage 2 can be corrected immediately before the carriage 2 turns around.

[0066] Furthermore, the manipulator control unit 105 causes the vision sensor 12 to capture an image of the marker L2 located immediately after the position where the carriage 2 is to be turned around on the path Q. In this way, by capturing an image of the marker L2 located immediately after the position where the carriage 2 is to be turned around on the path Q, the running position and running posture of the carriage 2 can be corrected immediately after the carriage 2 has turned around.

[0067] Furthermore, the work robot 1 pivots the cart 2 at the bend Qc of the path Q. By pivoting the cart 2 at the bend Qc of the path Q, it is possible to prevent a part of the work robot 1 from colliding with objects around the path Q when the cart 2 is turned due to an inner wheel difference of the cart 2 or the like.

[0068] Furthermore, when capturing an image including the marker L2, the work robot 1 stops the travel of the carriage 2. This prevents the effects of vibrations and the like that occur as the carriage 2 travels from affecting the vision sensor 12 attached to the tip 11a of the manipulator 11. This allows the marker L2 to be captured in a stable and favorable condition.

[0069] Furthermore, when the work robot 1 moves the cart 2 along the path Q, the manipulator 11 is folded so that the tip 11a of the manipulator 11 approaches the base end 11b of the manipulator 11 when viewed from above. This reduces the centrifugal force acting on the manipulator 11 during turning, thereby preventing excessive force from acting on the manipulator 11.

[0070] According to the control method for the working robot 1 as described above, the working robot 1 can be moved with a simple and low-cost configuration.

[0071] 10 is a diagram showing an example of the hardware configuration of the robot control device and the travel control device. A computer 900 includes a CPU 901, a main memory device 902, an auxiliary memory device 903, an input / output interface 904, and a communication interface 905.

[0072] The robot controller 10 and the travel controller 20 are each implemented in a computer 900. The above-described functions are stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903, loads it into the main storage device 902, and executes the above-described processing in accordance with the program. The CPU 901 also allocates a storage area in the main storage device 902 in accordance with the program. The CPU 901 also allocates a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0073] Alternatively, a program for implementing all or part of the functions of the robot controller 10 and the driving controller 20 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. If a WWW system is used, the term "computer system" also includes a website provision environment (or display environment). The term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. If the program is distributed to the computer 900 via a communication line, the computer 900 may load the program into the main storage device 902 and execute the processing described above. The program may also be for implementing part of the functions described above, or may be capable of implementing the functions described above in combination with a program already stored in the computer system.

[0074] Other Embodiments Although the embodiments have been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel.

[0075] Furthermore, in the above embodiment, when the bogie 2 is turned, the bogie 2 is pivoted on the spot by the plurality of wheels 23 made up of Mecanum wheels, but the bogie 2 may be provided with any other appropriate structure that allows pivoting, other than Mecanum wheels.

[0076] In the above embodiment, the manipulator 11 is provided so as to protrude outward in a plan view of the top plate 2t of the cart 2, but this is not limiting. The manipulator 11 may be provided on the top plate 2t as long as it is provided at a position offset to one side in the width direction (first direction) of the top plate 2t along the horizontal plane with respect to the center 2z of the top plate 2t of the cart 2.

[0077] <Additional Notes> The working robot 1 and the control method for the working robot 1 described in the embodiment can be understood, for example, as follows.

[0078] (1) A work robot 1 according to a first aspect includes a cart 2 capable of traveling on a floor surface F, a manipulator 11 that is located offset to one side in a first direction along a horizontal plane from a center 2z of a top plate 2t of the cart 2 and that can arbitrarily change the position and posture of its tip 11a, a vision sensor 12 attached to the tip 11a of the manipulator 11 and that can capture images including markers L2 that are located at predetermined positions on the floor surface F, and a control device 10, wherein the control device 10 includes a path acquisition unit 101 that acquires path information for the cart 2, including a path Q along which the cart 2 travels and the positions of a plurality of the markers L2 that are arranged along the path Q; The system includes a manipulator control unit 105 that controls the manipulator 11 so that the vision sensor 12 captures an image including the marker L2, and a detection unit 103 that detects the amount of deviation of the trolley 2 relative to the path Q based on the marker L2 contained in the image captured by the vision sensor 12, and a travel instruction unit 104 that instructs the trolley 2 to correct the running position or running posture of the trolley 2 based on the amount of deviation, and instructs the trolley 2 on the direction of travel of the trolley 2 so that the vision sensor 12 can capture an image including the marker L2 positioned on one side of the first direction relative to the trolley 2.

[0079] This working robot 1 guides the carriage 2 using a vision sensor 12 attached to the manipulator 11, eliminating the need for a separate mechanism for guiding the carriage 2. This allows the carriage 2 to be constructed with minimal equipment and cost, and to move the carriage 2 accurately along the path Q. As a result, the working robot 1 can be moved with a simple, low-cost configuration. Furthermore, the manipulator 11 of the working robot 1 is located offset to one side of the first direction along the horizontal plane from the center 2z of the tabletop 2t of the carriage 2. Therefore, compared to a case where the manipulator 11 is located on the center 2z of the tabletop 2t, the reach of the tip 11a of the manipulator 11 to one side of the tabletop 2t in the first direction is wider. Therefore, even if the marker L2 is separated from the path Q of the carriage 2 in a direction intersecting the extension direction of the path Q, the vision sensor 12 can easily detect the marker L2. As a result, the degree of freedom in the installation position of the marker L2 is increased. Furthermore, the dolly 2 is moved so that the vision sensor 12 can capture an image including the marker L2 arranged on one side in the first direction relative to the dolly 2. This makes it easier to capture an image of the marker L2 using the manipulator 11 provided at a position offset to one side in the first direction relative to the center 2z of the top plate 2t of the dolly 2. Furthermore, since the amount of movement of the manipulator 11 to one side in the first direction when capturing an image of the marker L2 is small, the time required for the operation of the manipulator 11 is shortened, and the image of the marker L2 can be captured efficiently.

[0080] (2) A work robot 1 according to a second aspect is the work robot 1 of (1), wherein the travel instruction unit 104 causes the cart 2 to travel along the path Q and instructs the cart 2 to move sequentially to positions where each of the multiple markers L2 arranged along the path Q can be photographed by the vision sensor 12, and the manipulator control unit 105 causes the vision sensor 12 to photograph an image including the marker L2 at the position where each of the multiple markers L2 can be photographed.

[0081] This allows the cart 2 to be moved sequentially to positions where each of the multiple markers L2 arranged along the route Q can be photographed, and the vision sensor 12 to capture an image including the markers L2, thereby allowing the cart 2 to move along the route Q with high precision while correcting its running position and running posture as it moves along the route Q.

[0082] (3) A work robot 1 according to a third aspect is the work robot 1 of (2), in which, when the next marker L2 placed along the path Q is placed on the opposite side of the path Q from one of the markers L2 photographed by the vision sensor 12, the travel instruction unit 104 turns the cart 2 so that one side of the first direction of the cart 2 is on the same side as the next marker L2 relative to the path Q.

[0083] As a result, when the next marker L2 arranged along the path Q is arranged on the opposite side of the path Q from one marker L2 photographed by the vision sensor 12, turning the cart 2 causes one side of the cart 2 in the first direction to be on the same side as the next marker L2 with respect to the path Q. Therefore, it becomes possible to photograph the next marker L2 well.

[0084] (4) A work robot 1 according to a fourth aspect is the work robot 1 of (3), in which the travel instruction unit 104 turns the cart 2 at a bend Qc of the path Q where the direction of travel of the cart 2 is changed so that one side of the first direction of the cart 2 is on the same side as the next marker L2 relative to the path Q.

[0085] This allows the cart 2 to turn around at bends Qc of the path Q where the direction of travel of the cart 2 changes, but prevents the cart 2 from turning around in the straight sections of the path Q. This makes it possible to prevent part of the work robot 1 from colliding with objects around the path Q when the cart 2 is turned around.

[0086] (5) The work robot 1 according to the fifth aspect is the work robot 1 of (3) or (4), in which the manipulator control unit 105 causes the vision sensor 12 to photograph the marker L2 located just before the position on the path Q where the cart 2 is to be turned.

[0087] This allows the traveling position and traveling posture of the carriage 2 to be corrected immediately before the carriage 2 turns by photographing the marker L2 located on the route Q just before the carriage 2 turns.

[0088] (6) The work robot 1 according to the sixth aspect is any one of the work robots 1 of (3) to (5), and the manipulator control unit 105 causes the vision sensor 12 to photograph the marker L2 located immediately after the position on the path Q where the cart 2 is turned.

[0089] This allows the traveling position and traveling posture of the carriage 2 to be corrected immediately after the carriage 2 turns by photographing the marker L2 located immediately after the position where the carriage 2 turns on the route Q.

[0090] (7) The work robot 1 according to a seventh aspect is any one of the work robots 1 of (3) to (6), wherein the cart 2 is capable of pivoting on the floor surface F, and the travel instruction unit 104 pivots the cart 2 at a bend Qc of the path Q.

[0091] This allows the trolley 2 to pivot at the bend Qc of the path Q, thereby preventing part of the work robot 1 from colliding with objects around the path Q when the trolley 2 is turned due to an inner wheel difference of the trolley 2, etc.

[0092] (8) The work robot 1 according to the eighth aspect is any one of the work robots 1 of (2) to (7), and the travel instruction unit 104 instructs the cart 2 to stop traveling when the vision sensor 12 captures an image including the marker L2 at a position where each of the multiple markers L2 can be photographed.

[0093] As a result, when capturing an image including the marker L2, the movement of the carriage 2 is stopped, thereby preventing the influence of vibrations and the like that occur as the carriage 2 moves from reaching the vision sensor 12 attached to the tip 11a of the manipulator 11. Therefore, the marker L2 can be captured in a stable and favorable state.

[0094] (9) A work robot 1 according to a ninth aspect is the work robot 1 of (8), wherein the manipulator control unit 105 extends the manipulator 11 when the vision sensor 12 captures an image including the marker L2 so that the tip 11a of the manipulator 11 is separated from the base end 11b of the manipulator 11 when viewed from above, and folds the manipulator 11 when the cart 2 travels along the path Q so that the tip 11a of the manipulator 11 is closer to the base end 11b of the manipulator 11 when viewed from above.

[0095] As a result, when the carriage 2 travels along the path Q, the centrifugal force acting on the manipulator 11 during turning can be reduced by folding the manipulator 11 so that the tip 11a of the manipulator 11 approaches the base end of the manipulator 11 when viewed from above. Therefore, it is possible to prevent excessive force from acting on the manipulator 11.

[0096] (10) A tenth aspect of the control method for a work robot 1 is a control method for a work robot 1 according to any one of (1) to (9), comprising step S101 of acquiring path information for the cart 2, including a path Q along which the cart 2 travels and the positions of a plurality of the markers L2 arranged along the path Q; step S102 of causing the cart 2 to travel along the path Q; step S103 of capturing an image including the markers L2 arranged along the path Q with the vision sensor 12; and step S104 of capturing the markers L2 included in the captured image. The method includes step S105 of detecting the amount of deviation of the trolley 2 relative to the path Q based on L2, and step S106 of instructing the trolley 2 to correct the running position or running posture of the trolley 2 based on the amount of deviation, and in step S102 of running the trolley 2, when an image including the marker L2 is captured by the vision sensor 12, the direction of travel of the trolley 2 is instructed to the trolley 2 so that the vision sensor 12 can capture an image including the marker L2 arranged on one side of the first direction relative to the trolley 2.

[0097] This allows the working robot 1 to be moved with a simple and low-cost configuration.

[0098] According to the work robot and the control method for the work robot disclosed herein, the work robot can be moved with a simple and low-cost configuration.

[0099] DESCRIPTION OF SYMBOLS 1...Working robot 2...Cart 2a...Long side 2t...Top plate 2z...Central portion 10...Robot control device (control device) 11...Manipulator 11a...Tip 11b...Base end 12...Vision sensor 101...Path acquisition unit 103...Detection unit 104...Travel instruction unit 105...Manipulator control unit D1...Path information D2...Image D4...Travel instruction F...Floor surface L2, L2a to L2f...Markers Q...Path Qc, Qc2...Bend portion

Claims

1. A work robot comprising: a cart capable of traveling on a floor surface; a manipulator that is located offset to one side in a first direction along a horizontal plane from the center of the top plate of the cart, and whose tip position and attitude can be arbitrarily changed; a vision sensor attached to the tip of the manipulator and capable of capturing images including markers located at predetermined positions on the floor surface; and a control device, wherein the control device comprises: a path acquisition unit that acquires path information for the cart, including the path along which the cart will travel and the positions of a plurality of the markers arranged along the path; a manipulator control unit that controls the manipulator to capture images including the markers with the vision sensor; a detection unit that detects the amount of deviation of the cart with respect to the path based on the markers included in the images captured by the vision sensor; and a travel instruction unit that instructs the cart to correct the traveling position or traveling attitude of the cart based on the amount of deviation, and instructs the cart on the direction of travel of the cart so that the vision sensor can capture images including the markers arranged on one side of the cart in the first direction.

2. The work robot described in claim 1, wherein the driving instruction unit drives the cart along the route and instructs the cart to move sequentially to positions where each of the multiple markers arranged along the route can be photographed by the vision sensor, and the manipulator control unit causes the vision sensor to capture images including the markers at the positions where each of the multiple markers can be photographed.

3. A work robot as described in claim 2, wherein, when a next marker placed along the path is placed on the opposite side of the path from one of the markers photographed by the vision sensor, the driving instruction unit turns the cart so that one side of the first direction of the cart is on the same side as the next marker in relation to the path.

4. A work robot as described in claim 3, wherein the driving instruction unit turns the cart at a bend in the path where the direction of travel of the cart is changed so that one side of the first direction of the cart is on the same side of the path as the next marker.

5. A work robot according to claim 3 or 4, wherein the manipulator control unit causes the vision sensor to capture an image of the marker located immediately before a position on the path where the carriage is to be turned around.

6. A work robot according to claim 3 or 4, wherein the manipulator control unit causes the vision sensor to photograph the marker located immediately after the position on the path where the carriage is to be turned around.

7. A work robot according to claim 3 or 4, wherein the carriage is pivotable on the floor surface, and the travel instruction unit pivots the carriage at bends in the path.

8. The work robot according to claim 2, wherein the driving instruction unit instructs the cart to stop driving when the vision sensor captures an image including the markers at a position where each of the markers can be photographed.

9. The work robot described in claim 8, wherein the manipulator control unit extends the manipulator so that the tip of the manipulator is away from the base end of the manipulator when viewed from above when the vision sensor captures an image including the marker, and folds the manipulator so that the tip of the manipulator is closer to the base end of the manipulator when viewed from above when the cart is traveling along the path.

10. A control method for a work robot as defined in claim 1 or 2, comprising the steps of: acquiring path information for the cart, including the path along which the cart will travel and the positions of a plurality of the markers arranged along the path; driving the cart along the path; capturing an image with the vision sensor that includes the markers arranged along the path; detecting the amount of deviation of the cart from the path based on the markers included in the captured image; and instructing the cart to correct the traveling position or traveling attitude of the cart based on the amount of deviation, wherein in the step of driving the cart, when capturing an image including the markers with the vision sensor, the direction of travel of the cart is instructed to the cart so that the vision sensor can capture an image including the markers that are arranged on one side of the cart in the first direction.

Images