Work robot, control method for work robot

Abstract

A work robot includes: a dolly; a robot arm disposed at a position offset in a first direction along a horizontal plane from a central portion of a top plate of the dolly; a vision sensor mounted at a distal end of the robot arm; and a control device including: a path acquisition portion that acquires path information of the dolly; a robot arm control portion that controls the robot arm; a detection portion that detects an offset amount of the dolly with respect to the path based on a marker included in an image captured by the vision sensor; and a travel instruction portion that instructs the dolly to correct a travel position or a travel posture of the dolly based on the offset amount, and that instructs the dolly to capture an image including a marker disposed on a side in the first direction with respect to the dolly using the vision sensor.

Description

Technical Field

[0001] This invention relates to a work robot and a control method for the work robot. 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. Background Technology

[0002] Consider mounting a robot (robotic arm) on an Automated Guided Vehicle (AGV) to automatically transport the robot to the work location (e.g., see Patent Document 1).

[0003] Previous technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 2680298 Summary of the Invention

[0006] The technical problem to be solved by the invention

[0007] AGVs equipped with robots travel autonomously using guidance methods such as magnetic induction or optical guidance. Generally, commercially available AGVs are equipped with sensors corresponding to the guidance method or various functions for autonomous driving control, offering high functionality but at a high price. Therefore, when introducing commercially available AGVs into a factory, features not used in the factory (such as automated material handling scheduling or map creation functions) may be included, potentially making the equipment structure or cost too high for the intended purpose.

[0008] Furthermore, if the AGV cannot move precisely to the correct working position, it will cause a misalignment between the robot and the workpiece, making it difficult for the robot to move the tool to the correct working point on the workpiece. This will result in a decrease in the accuracy of robot-based operations.

[0009] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a work robot that can move with a simple and low-cost structure, a marking component for the work robot, and a control method for the work robot.

[0010] means for solving technical problems

[0011] To address the aforementioned issues, the present invention relates to a work robot comprising: a trolley capable of traveling on the ground; a robotic arm disposed at a position offset to one side along a first direction relative to the center of the trolley's top plate, capable of arbitrarily changing the position and posture of its end effector; a vision sensor mounted on the end effector of the robotic arm, capable of capturing images including marks disposed at predetermined positions on the ground; and a control device comprising: a path acquisition unit, acquiring path information of the trolley including the path traveled by the trolley and the positions of a plurality of marks disposed along the path; a robotic arm control unit, controlling the robotic arm to capture images including the marks using the vision sensor; a detection unit, detecting the offset of the trolley relative to the path based on the marks contained in the images captured by the vision sensor; and a travel instruction unit, instructing the trolley to correct its travel position or posture based on the offset, and instructing the trolley to travel in the direction of travel, thereby enabling the capture of images including the marks disposed to one side relative to the trolley in the first direction using the vision sensor.

[0012] The control method for the work robot involved in this invention is the control method for the work robot as described above, which includes the following steps: acquiring path information of the trolley including the path on which the trolley travels and the positions of a plurality of markers arranged along the path; capturing an image including the markers arranged along the path using the vision sensor; detecting the offset of the trolley relative to the path based on the markers contained in the captured image; and instructing the trolley to correct the trolley's travel position or travel posture based on the offset. In the step of making the trolley travel, when capturing an image including the markers using the vision sensor, the trolley's travel direction is indicated to the trolley so that the vision sensor can capture an image including the markers arranged on one side relative to the trolley in the first direction.

[0013] Invention Effects

[0014] The work robot and its control method according to the present invention enable the work robot to move with a simple and low-cost structure. Attached Figure Description

[0015] Figure 1 This is a diagram showing the overall structure of the robot system involved in this embodiment.

[0016] Figure 2 From and Figure 1 The diagram of the work robot involved in this embodiment is viewed from different directions.

[0017] Figure 3This is a top view of the work robot involved in this embodiment.

[0018] Figure 4 This is a block diagram illustrating the functional structure of the robot control device and the driving control device involved in this embodiment.

[0019] Figure 5 This diagram shows the state in which the driver of the robot involved in this embodiment is folded.

[0020] Figure 6 This is a flowchart illustrating an example of the trolley's movement processing based on the robot system described in this embodiment.

[0021] Figure 7 This is a diagram illustrating an example of the path information involved in this embodiment.

[0022] Figure 8 This is a diagram used to illustrate the driving process of the robot system involved in this embodiment.

[0023] Figure 9 This is a diagram illustrating an example of the actions of a robot working along a path.

[0024] Figure 10 This is a diagram illustrating an example of the hardware structure of a robot control device and a motion control device. Detailed Implementation

[0025] Hereinafter, with reference to the accompanying drawings, a method for controlling the robot system and the robot system used to implement the present invention will be described. However, the present invention is not limited to this embodiment.

[0026] (Overall structure of the robot system)

[0027] Figure 1 This is a diagram showing the overall structure of the robot system involved in this embodiment. For example... Figure 1 As shown, the work robot system 100 includes a work robot 1 and an operating PC 3. The work robot 1 automatically performs tasks instructed by an operator in a workspace such as a factory or warehouse. The work robot 1 includes a trolley 2, a robotic arm 11, a vision sensor 12, and a robot control device 10.

[0028] (Structure of the trolley)

[0029] Figure 2 From and Figure 1 Figures showing the working robot involved in this embodiment viewed from different directions. Figure 3 This is a top view of the work robot involved in this embodiment.

[0030] The trolley 2 is, for example, an automated guided vehicle (AGV). In this embodiment, the trolley 2 is rectangular in shape when viewed from above. Figures 1-3 As shown, the trolley 2 has a top plate 2t and side plates 2s. The top plate 2t faces upward and can carry items transported by the robot 1. The side plates 2s extend downward from the four sides of the top plate 2t. Figure 1 As shown, the trolley 2 is equipped with a driving control device 20, a drive device 21, wheels 23 and a stopper 24.

[0031] As will be described in detail later, the driving control device 20 controls the drive device 21 to move (drive), stop, change speed, etc., according to the driving instructions of the robot control device 10.

[0032] The drive unit 21 is a motor for moving the wheels 23 of the trolley 2. In this embodiment, the wheels 23 are Mecanum wheels (registered trademark) with multiple rollers, and the drive unit 21 has one motor for each wheel 23. The drive unit 21 changes the combination of rotating wheels 23 or the rotation speed and direction of rotation of each wheel 23 according to the control command of the travel control unit 20. As a result, the trolley 2 can move in any direction.

[0033] like Figure 3 As shown, the trolley 2 travels primarily along the long side 2a of the rectangular top plate 2t when viewed from above, via multiple wheels 23 (Mecanum wheels). That is, the trolley 2 moves one of the two short sides 2b and 2c of the rectangular top plate 2t when viewed from above towards the front of the direction of travel, and the other side towards the rear of the direction of travel.

[0034] Additionally, in the following description, the main direction of travel of the trolley 2 based on multiple wheels 23 (Mecanum wheels) (the direction along the long side of the top plate 2t) is sometimes referred to as the X-axis direction, and the width direction (first direction) of the trolley 2 that intersects the X-axis direction in the horizontal plane and connects the short sides 2b and 2c is referred to as the Y-axis direction.

[0035] like Figure 1 As shown, the stopper 24 is a device used to fix the trolley 2 in place after it has moved to a designated position.

[0036] The trolley 2 may also be equipped with a driving assistance sensor (not shown). The driving assistance sensor is a sensor used to detect the position or direction of travel of the trolley 2, enabling the trolley 2 to move autonomously when there is no driving instruction from the robot control device 10 described later. In this embodiment, the driving assistance sensor includes a position detection sensor that detects the amount of movement of the trolley 2 in the horizontal direction (X-axis and Y-axis). The position detection sensor uses the same technology as a so-called optical mouse, reading patterns on the ground to detect the amount of movement of the trolley 2 in the X-axis and Y-axis directions. Furthermore, the driving assistance sensor may also include a gyrocompass for detecting the direction of travel of the trolley 2.

[0037] (Structure of robotic arm and vision sensor)

[0038] like Figures 1-3 As shown, the robotic arm 11 is mounted on the trolley 2. In a top-down view, the robotic arm 11 is positioned offset from the center 2z of the top plate 2t of the trolley 2 towards one side along the width direction (Y-axis direction) of the trolley 2 in the horizontal plane. In this embodiment, in a top-down view, the robotic arm 11 is positioned on the outer side of the top plate 2t of the trolley 2. In this embodiment, the work robot 1 has a support base 15 for supporting the robotic arm 11. The support base 15 is configured to protrude outwards from the outer side 2s of the top plate 2t of the trolley 2 in a top-down view. The support base 15 is configured to protrude from the upper end of the side 2s on one side in the width direction towards one side (the first direction) of the width direction of the trolley 2 within the trolley 2.

[0039] A robotic arm 11 is mounted on a support base 15. The robotic arm 11 is a multi-joint robotic arm with multiple joints 11j. The base end 11b of the robotic arm 11 is fixed to the support base 15. The robotic arm 11 is constructed by rotatably connecting multiple arm components 11d via joints 11j. The robotic arm 11 allows for arbitrary changes in the position and posture of the end effector 11a by rotating each joint. Furthermore, the structure of the robotic arm 11, including the number of joints 11j, is not limited and can be any structure.

[0040] A tool 13 is detachably mounted on the end effector 11a of the robotic arm 11. The tool 13 is an instrument used to perform various tasks. The tasks performed by the robot 1 include, for example, welding, assembly tasks such as screw tightening or drilling, picking tasks such as holding and moving parts, finishing, ultrasonic inspection, and appearance inspection. The tool 13 corresponding to the task is mounted on the end effector 11a of the robotic arm 11.

[0041] A vision sensor 12 is mounted on the end effector 11a of the robotic arm 11. The vision sensor 12 is a camera that captures images of the surrounding area of ​​the robot 1. Figure 1An example of a vision sensor 12 with a CCD camera 12A and a 3D camera 12B is shown.

[0042] The vision sensor 12 is capable of capturing images of the marker L set in the area where the robot 1 moves. In this embodiment, the marker L includes a guide line L1 and a marker L2.

[0043] (Structure of the guide line)

[0044] Guide line L1 is set on the ground F in the area where the work robot 1 travels. Guide line L1 is used to guide the travel direction of work robot 1, and therefore extends in a specified direction on the ground F.

[0045] (Structure of the marker)

[0046] Marker L2 is set at a predetermined position on the ground F. Multiple markers L2 may be set at locations such as overlapping with guide line L1, near locations where they do not overlap with guide line L1, near the bends of guide line L1, along the path of the work robot 1, at the stopping position of the work robot 1, and at positions where the travel direction of the work robot 1 changes. In this embodiment, multiple markers L2 are set at predetermined intervals, for example, along the extension direction of guide line L1.

[0047] Marker L2 includes information related to its location on the ground F. In this embodiment, marker L2 is, for example, a QR code (registered trademark).

[0048] (Structure of the robot control device)

[0049] A robot control device 10 is mounted on the work robot 1. The robot control device 10 controls the movements of various parts of the work robot 1. In this embodiment, the robot control device 10 causes the trolley 2 to travel to a designated location. The designated location may be, for example, a work position where the work robot 1 performs its work or a storage location for the work robot 1. The designated location is specified by the operator of the work robot 1 via the operation PC 3.

[0050] (Structure of operating a PC)

[0051] The operating PC3 is a computer operated by the operator of the work robot 1. The operating PC3 communicates wirelessly with the work robot 1. The operating PC3 receives commands from the operator, instructing the work robot 1 to reach the designated location and the path (via locations, etc.) to that location.

[0052] (Functional structure of robot control device)

[0053] Figure 4This is a block diagram illustrating the functional structure of the robot control device and the driving control device involved in this embodiment. For example... Figure 4 As shown, the robot control device 10 includes a path acquisition unit 101, a sensor information acquisition unit 102, a detection unit 103, a driving instruction unit 104, and a robotic arm control unit 105.

[0054] The path acquisition unit 101 acquires path information D1 from the operation PC3. The path information D1 includes the path Q from the current position of the trolley 2 to the specified position, the guide line L1 configured along the path Q, and the positions of multiple markers L2. Furthermore, the path information D1 includes information indicating which side of the path Q the guide line L1 or each marker L2 is configured on.

[0055] 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 while the trolley 2 is moving.

[0056] The detection unit 103 detects the offset of the carriage 2 relative to the specified path Q based on the guide line L1 and mark L2 included in the image captured by the vision sensor 12 (CCD camera 12A).

[0057] The driving instruction unit 104 outputs driving instructions D4 to the trolley 2 (driving control device 20) indicating driving position, stopping, speed, etc.

[0058] For example, the driving instruction unit 104 instructs the trolley 2 to control its driving direction (angle) based on the driving direction of the trolley 2 detected by the detection unit 103 according to the guide line L1. Furthermore, the driving instruction unit 104 instructs the trolley 2 to correct its driving position or driving direction (angle) based on the offset of the trolley 2 detected by the detection unit 103 according to the mark L2.

[0059] In order to detect the offset of the trolley 2, the travel instruction unit 104 instructs the trolley 2 to travel in a manner that allows the vision sensor 12 to capture images including guide lines L1 and markers L2, indicating the travel position or direction of travel of the trolley 2. The travel instruction unit 104 instructs the trolley 2 to travel along path Q, and to move the trolley 2 sequentially to a position where the vision sensor 12 can capture images of each of the plurality of markers L2 arranged along path Q.

[0060] Furthermore, when the driving instruction unit 104 captures an image including the mark L2 using the vision sensor 12 at a position where it can capture images of each of the multiple marks L2, it instructs the trolley 2 to stop its movement. Therefore, compared to the case where the trolley 2 is driven while the vision sensor 12 is capturing images without stopping the trolley 2, the effects of vibrations during driving can be suppressed, thus enabling better capture of the marks L2. In other words, the driving instruction unit 104 drives the trolley 2 along path Q, and stops the trolley 2 when capturing images using the vision sensor 12. Thus, the trolley 2 repeats its movement along path Q and the subsequent image capture by the vision sensor 12.

[0061] The robot 1 has a robotic arm 11 on one side of the trolley 2 in the width direction (first direction) relative to the trolley 2. Therefore, when using the vision sensor 12 mounted on the robotic arm 11 to capture images of the guide line L1 and the mark L2, it is preferable to have the robotic arm 11 positioned on the side of the trolley 2 with respect to the guide line L1 and the mark L2 in the width direction relative to the trolley 2. The travel instruction unit 104 instructs the trolley 2 on its travel direction in a manner that allows the vision sensor 12 to capture images including the mark L2 positioned on one side of the trolley 2 in the width direction. That is, when the guide line L1 and the mark L2 are positioned on the opposite side (the opposite side) of the travel trolley 2 in the width direction, the travel instruction unit 104 instructs the trolley 2 to turn so that the trolley 2 reverses in the forward and backward direction, and the guide line L1 and the mark L2 are positioned on one side of the travel trolley 2 in the width direction. Furthermore, if the guide lines L1 and markers L2 are positioned on both sides of the traveling trolley 2 in the width direction, but for some reason the guide lines L1 and markers L2 should be positioned on the other side in the width direction, the travel instruction unit 104 instructs the trolley 2 to turn so that the trolley 2 reverses in the forward and backward direction.

[0062] The driving instruction unit 104 instructs the trolley 2 to turn when, as the trolley 2 travels along path Q, a marker L2 to be captured by the vision sensor 12 is switched from one side of the trolley 2 in the width direction to the other, or vice versa. For example, after capturing a marker L2 captured by the vision sensor 12, if the next marker L2, positioned ahead of the marker L2 captured by the vision sensor 12 in the travel direction of path Q, is positioned on the opposite side in the width direction across path Q, the trolley 2 is turned, reversing the travel direction. Thus, the next marker L2 to be captured is on the same side in the width direction as one side of the trolley 2 on which the robotic arm 11 is mounted.

[0063] When the trolley 2 is turned according to the side marked L2, the travel instruction unit 104 instructs the trolley 2 to pivot, so that the trolley 2 pivots in place via multiple wheels 23 consisting of Mecanum wheels. That is, instead of changing the orientation of the trolley 2 by turning it along path Q, the trolley 2 is turned in place. As a result, when the trolley 2 is turned, the robotic arm 11 or the corners of the trolley 2 are less likely to interfere with (collide with) surrounding equipment or objects.

[0064] When the trolley 2 is turned according to the side marked L2, the travel indicator 104 at the bend Qc of the path Q of the trolley 2 changing the direction of travel (see reference) Figure 9 The curved section Qc, compared to the straight section Q, sometimes makes it easier to ensure a wider space, so that when turning the trolley 2, the robotic arm 11 or the corner of the trolley 2 is less likely to interfere (collide) with surrounding equipment or objects.

[0065] The robotic arm control unit 105 controls the robotic arm 11 to position or pose the vision sensor 12 or tool 13 in any manner. For example... Figure 1 , Figure 2 As shown, during the movement of the trolley 2, the robotic arm control unit 105 controls the robotic arm 11 to position the vision sensor 12 downwards. The robotic arm control unit 105 controls the robotic arm 11 to capture an image including the marker L2 using the vision sensor 12. The robotic arm control unit 105 controls the robotic arm 11 to capture an image including the marker L2 at each possible image capture position of the plurality of markers L2 using the vision sensor 12. At each possible image capture position of the plurality of markers L2, the robotic arm control unit 105 extends the robotic arm 11 so that, when viewed from above, the end 11a of the robotic arm 11 is away from the base 11b of the robotic arm 11.

[0066] Figure 5 This diagram shows the state in which the driver of the robot involved in this embodiment is folded.

[0067] When trolley 2 travels along path Q, such as Figure 5 As shown, the robotic arm control unit 105 folds the robotic arm 11 so that, when viewed from above, the end 11a of the robotic arm 11 is close to the base 11b of the robotic arm 11. In this case, it is preferable to fold the robotic arm 11 so that the multiple arm components 11d constituting the robotic arm 11 or the vision sensor 12 are located as vertically above the base 11b as possible. This suppresses excessive force such as torque or centrifugal force caused by vibrations generated during the movement of the trolley 2 on the joints 11j of the robotic arm 11, and prevents adverse effects on the movement of the robotic arm 11 or the occurrence of malfunctions.

[0068] When turning the trolley 2 on path Q, the robotic arm control unit 105 preferably uses the vision sensor 12 to capture a mark L2 located immediately before the position where the trolley 2 turns on path Q. This allows the position and posture of the trolley 2 to be corrected before turning.

[0069] Furthermore, the robotic arm control unit 105 preferably uses the vision sensor 12 to capture a mark L2 located immediately after the position where the trolley 2 turns on the path Q. Thus, even if the wheels 23 slip on the ground F during the turn, the position and posture of the trolley 2 can be corrected after the turn.

[0070] (Functional structure of the driving control device)

[0071] like Figure 4 As shown, the driving control device 20 includes a motor control unit 201.

[0072] The motor control unit 201 controls the drive unit 21 to move, stop, or change the speed of the trolley 2. When there is no driving instruction from the robot control unit 10, the motor control unit 201 can control the drive unit 21 based on the sensor values ​​(movement amount and direction of travel) of the driving assistance sensor (not shown) to enable the trolley 2 to autonomously travel to the designated position.

[0073] Furthermore, when the trolley 2 is moved, its position and direction of travel may deviate from the designated path due to factors such as uneven ground in the factory, slippage of the wheels 23 on the ground F, and inability to read the guide line L1. Therefore, in this embodiment, when the mark L2 is captured by the vision sensor 12, the robot control device 10 of the work robot 1 detects the deviation of the trolley 2 from the path based on the captured mark L2, and issues a driving instruction to the trolley 2's driving control device 20 to correct the driving position. The motor control unit 201 of the driving control device 20 controls the drive device 21 to adjust the driving position of the trolley 2 according to the driving instruction of the robot control device 10.

[0074] Furthermore, as described above, the wheels 23 of the trolley 2 in this embodiment are Mecanum wheels. The motor control unit 201 may include a calculation unit 201A for calculating control command values ​​representing the presence, direction, and speed of rotation of the travel motors of each wheel 23. For example, if the coordinates of the destination are assigned, the calculation unit 201A calculates the control command values ​​of each travel motor to orient the trolley 2 toward the coordinates of the destination. The motor control unit 201 controls the travel motors based on the control command values ​​calculated by the calculation unit 201A.

[0075] (Rotation processing of robot-based trolleys)

[0076] Figure 6 This is a flowchart illustrating an example of the driving process of a trolley based on the robot according to this embodiment. Figure 7 This is a diagram illustrating an example of the path information involved in this embodiment. Figure 8 This diagram illustrates the movement process of the robot according to this embodiment. Here, refer to... Figures 6-8 The process of handling the movement of the trolley 2 based on the robot control device 10 of the work robot 1 is explained.

[0077] The path acquisition unit 101 acquires path information D1, representing the path from the current position of the trolley 2 to the specified position, from the operation PC3. Figure 4 (Step S101). The specified location is, for example, the working position of the work robot 1. The specified location and path are input by the operator via the operation PC3. Figure 7 As shown, the path information D1 represents the coordinates (X, Y, Z) of the starting position (current position), the passing position and the specified position (destination), as well as the posture (W, P, R) of the trolley 2 at each position.

[0078] If path information D1 is obtained, the robot control device 10 causes the trolley 2 to start moving according to the path information D1 (step S102).

[0079] Here, the robot control device 10 identifies, based on the acquired path information D1, whether the next marker L2, located ahead of the current position of the carriage 2 along the travel direction of path Q, is located on one side or the other side of the width direction of path Q. If, at the current position of the carriage 2, the next marker L2 is located on the side opposite to the side where the robotic arm 11 is located in the width direction, the robot control device 10 turns the carriage 2, reversing its travel direction. Furthermore, after positioning the robotic arm 11 on the same side as the next marker L2 in the width direction of the carriage 2, the carriage 2 proceeds along path Q.

[0080] After the trolley 2 starts moving, the robot control device 10 takes a picture through the vision sensor 12 and acquires the captured image D2 (step S103). Figure 1 and Figure 8 As shown, in this embodiment, for example, the work robot 1 takes an image D2 with the vision sensor 12 facing downward (towards the ground) in the vertical direction.

[0081] The detection unit 103 determines whether guide lines L1 and L2, which serve as markers L, are detected based on the acquired image D2 (step S104). If guide line L1 is detected in the acquired image D2 (step S104: "Yes"), the traveling direction of the trolley 2 and the amount of offset of the trolley 2 in the Y direction are detected based on the detection information D3 of guide line L1 (step S105). For example, the detection unit 103 detects the amount of offset indicating how much the position of the trolley 2 has shifted in the Y direction based on the position of guide line L1 in image D2. Furthermore, the detection unit 103 detects the amount of offset indicating how much the traveling direction of the trolley 2 has shifted based on the angle of guide line L1 in image D2.

[0082] Furthermore, if mark L2 is detected based on image D2 (step S104: "Yes"), the detection unit 103 detects the coordinates (X, Y) and angle (angle R around the Z-axis) of the detection position of mark L2 in image D2 (step S105). Based on the coordinates and angle of mark L2, the detection unit 103 detects the amount of offset indicating how much the position and direction of travel of the trolley 2 have deviated.

[0083] Next, the driving instruction unit 104 outputs a driving instruction D4 to the trolley 2 in a manner that reduces the offset of the trolley 2 based on the detected offset and driving position (step S106).

[0084] For example, such as Figure 8 As shown in (a), when a deviation in the Y direction is detected according to the guide line L1, the travel instruction unit 104 outputs a travel instruction D4 to correct the position of the trolley 2 in the Y direction. This travel instruction is represented, for example, by the relative coordinates (X, Y) of the corrected position relative to the current position of the trolley 2. If the trolley 2 can change its direction of travel via the steering mechanism, the relative angle (R) of the corrected direction of travel relative to the current direction of travel can also be included in the travel instruction D4. In addition, the travel instruction unit 104 can also output a travel instruction D4 to correct the travel position of the trolley 2 if the deviation is above a preset allowable value. That is, if the deviation is less than the allowable value, the position correction of the trolley 2 may not be performed.

[0085] And, as Figure 8As shown in (b), when the travel position of the trolley 2 is detected based on the marker L2, the travel instruction unit 104 outputs a travel instruction D4 indicating the coordinates of the trolley 2's next destination, stopping, speed change, etc., based on the trolley 2's travel position and path information D1. For example, suppose the path information D1 includes a path for moving in the Y direction after reaching a certain work area (area3) after moving in the X direction. In this case, if the trolley 2 is detected to have reached the work area (area3) based on the reading result of the marker L2, the travel instruction unit 104 outputs a travel instruction D4 specifying the coordinates of the next destination to the trolley 2. In addition, if the reading result of the marker L2 includes information indicating "stop", "90° turn" or "travel speed", the travel instruction unit 104 can include instructions such as stopping, 90° turn, and speed change (acceleration or deceleration) in the travel instruction D4 based on the reading result. Furthermore, when the trolley 2 is stopped, the driving instruction unit 104 can detect the offset of the detection position of the marker L2, output a driving instruction D4 for adjusting the position and posture of the trolley 2, and output a driving instruction D4 indicating that the trolley 2 has been stopped after adjusting the position and posture of the trolley 2.

[0086] Then, the robot control device 10 determines whether the trolley 2 is stopped at the designated position (step S107). For example, if it was indicated in step S105 that the trolley 2 should stop at the designated parking position (within the work area that becomes the destination) (step S107; "Yes"), the robot control device 10 stops the trolley 2. On the other hand, if it was not indicated in step S105 that the trolley 2 should stop at the designated parking position (step S107; "No"), the robot control device 10 returns to step S103 and continues the trolley 2's movement process (steps S103 to S107).

[0087] In step S107, when the trolley 2 stops at the designated position (step S107; "Yes"), the work robot 1 reads the mark L2 (upper mark L2a) through the vision sensor 12 (step S108). Based on the information included in the read mark L2 (QR code), the work robot 1 performs prescribed processes such as self-positioning or interlocking before the next action.

[0088] (Example of the actions of a robot working along a path)

[0089] Figure 9 This is a diagram illustrating an example of the actions of a robot working along a path. Additionally, Figure 9 The configuration shown for path Q or the region with path Q is just one example.

[0090] like Figure 9As shown, at position P1, the robot 1 is aligned with the direction of travel of the trolley 2 so that the robotic arm 11 is positioned on the same side as the mark L2a to be photographed in the width direction of the trolley 2. For example, when the robot 1 is being taken out of the storage location, the direction of travel of the trolley 2 is also aligned so that the robotic arm 11 is positioned on the same side as the first mark L2a to be photographed.

[0091] Then, the trolley 2 is moved along path Q, and the markers L2b, L2c, and L2d located on the same side as the robotic arm 11 are photographed sequentially to correct the trolley 2's driving position and posture. Specifically, at position P2 where marker L2c is located, the trolley 2's driving direction is changed, causing it to turn right. The trolley 2 photographs the marker L2c on the inner side of path Q after the driving direction change to correct its driving position and posture. At this time, the trolley 2 pivots at the bend Qc1 of path Q. Preferably, the marker L2c is photographed before and after the trolley 2 turns to correct its driving position and posture.

[0092] At position P3 where marker L2d is set, after photographing marker L2d and correcting its driving position and posture, the trolley 2 moves along path Q towards a position where it can photograph the next marker L2e. The next marker L2e is at the current position (position P3), located on the side where the robotic arm 11 is set in the width direction of the trolley 2 (in... Figure 9 In the example, the opposite side in the width direction (to the right of the direction of travel). Therefore, when changing the travel direction of trolley 2 to turn right, trolley 2 is turned, and the front and back of trolley 2 are reversed. At this time, trolley 2 pivots at position P4 of the bend Qc2 in path Q. After trolley 2 turns, mark L2e is photographed to correct the travel position and travel posture. At this time, if mark L2e is far away from trolley 2 in the width direction after turning, trolley 2 can be translated in the width direction by the wheels 23 composed of Mecanum wheels, so that trolley 2 is closer to mark L2e or guide line L1.

[0093] Then, the trolley 2 is moved further along path Q, and the markers L2f, L2g, and L2h set on the same side as the robotic arm 11 in the width direction of the trolley 2 are photographed in sequence to correct the driving position and driving posture of the trolley 2.

[0094] (Functions and Effects)

[0095] As described above, the work robot 1 according to this embodiment guides the trolley 2 using a vision sensor 12 mounted on the robotic arm 11, eliminating the need for a separate mechanism for guiding the trolley 2. Therefore, it is possible to construct the trolley 2 with minimal equipment and cost, and to move the trolley 2 along the path Q with high precision. As a result, the work robot 1 can be moved with a simple and low-cost structure.

[0096] Furthermore, the robotic arm 11 of the work robot 1 is positioned offset to one side relative to the center 2z of the top plate 2t of the trolley 2 in the width direction (first direction) of the top plate 2t along the horizontal plane. Therefore, compared to the case where the robotic arm 11 is positioned at the center 2z of the top plate 2t, the extent to which the end point 11a of the robotic arm 11 reaches one side of the top plate 2t in the first direction is wider. Therefore, even if the marker L2 moves away from the path Q of the trolley 2 in a direction intersecting the extension direction of the path Q, the marker L2 can be easily detected using the vision sensor 12. As a result, the degree of freedom in the placement of the marker L2 is increased.

[0097] Furthermore, by moving the trolley 2, an image of the mark L2, which is positioned on one side relative to the trolley 2 in the first direction, can be captured using the vision sensor 12. Thus, the mark L2 can be easily captured using the robotic arm 11, which is positioned offset to one side in the first direction relative to the center 2z of the top plate 2t of the trolley 2. Moreover, the amount of movement of the robotic arm 11 to one side in the first direction when capturing the mark L2 is also small, thereby shortening the time required for the robotic arm 11 to move and enabling efficient capture of the mark L2.

[0098] Furthermore, the robot 1 moves the trolley 2 sequentially to a position where it can capture images of each of the multiple markers L2 arranged along path Q, and the vision sensor 12 captures images including the markers L2. Thus, the robot can precisely move the trolley 2 along path Q while correcting its position and posture.

[0099] Furthermore, when the next marker L2 positioned along path Q is located on the opposite side of a marker L2 captured by the vision sensor 12 across path Q, the robot 1 turns the travel direction of the trolley 2 so that one side of the trolley 2 in the first direction is on the same side as the next marker L2 relative to path Q. Therefore, it is possible to capture the next marker L2 effectively.

[0100] Furthermore, the robot 1 turns the trolley 2 at the bend Qc of the path Q so that the robotic arm 11 is on the same side as the next marker L2 relative to the path Q.

[0101] Therefore, the trolley 2 can be turned at the curved section Qc of the path Q that changes the direction of travel of the trolley 2, and the trolley 2 can be prevented from turning at the straight section of the path Q. Thus, it is possible to suppress collisions between a part of the working robot 1 and objects around the path Q when the trolley 2 is turned.

[0102] Furthermore, the robotic arm control unit 105 causes the vision sensor 12 to capture a mark L2 located immediately preceding the position on path Q where the trolley 2 is turned.

[0103] Therefore, by photographing the marker L2 located immediately before the position where the trolley 2 turns on path Q, the driving position and driving posture of the trolley 2 can be corrected before the trolley 2 turns.

[0104] Furthermore, the robotic arm control unit 105 causes the vision sensor 12 to capture a mark L2 located immediately after the position on path Q that causes the trolley 2 to turn.

[0105] Therefore, by photographing the marker L2 located immediately after the position on path Q where the trolley 2 turns, the driving position and driving posture of the trolley 2 can be corrected immediately after the trolley 2 turns.

[0106] Furthermore, the working robot 1 causes the trolley 2 to pivot at the bend Qc of the path Q.

[0107] Therefore, by pivoting the trolley 2 at the bend Qc of the path Q, it is possible to suppress collisions between a portion of the working robot 1 and objects around the path Q when the trolley 2 is turned due to the inner wheel difference, etc.

[0108] Furthermore, when the robot 1 is capturing images including the marker L2, it stops the trolley 2. This suppresses the impact of vibrations and other effects caused by the movement of the trolley 2 on the vision sensor 12 mounted on the end effector 11a of the robotic arm 11. Therefore, capturing images of the marker L2 can be performed stably and reliably.

[0109] Furthermore, while the robot 1 is moving the trolley 2 along path Q, the robot 1 folds the robotic arm 11 so that, when viewed from above, the end 11a of the robotic arm 11 is close to the base 11b of the robotic arm 11. This reduces the centrifugal force acting on the robotic arm 11 during turning. Therefore, excessive force acting on the robotic arm 11 can be suppressed.

[0110] According to the control method of the work robot 1 described above, the work robot 1 can be moved with a simple and low-cost structure.

[0111] <Hardware Structure>

[0112] Figure 10This diagram illustrates an example of the hardware structure of a robot control device and a motion control device. The computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905.

[0113] The robot control device 10 and the driving control device 20 are respectively installed in the computer 900. Furthermore, the aforementioned functions are stored as programs in the auxiliary storage device 903. The CPU 901 reads the program from the auxiliary storage device 903 and expands it to the main storage device 902, executing the aforementioned processing according to the program. The CPU 901 also secures a storage area in the main storage device 902 according to the program. The CPU 901 also secures a storage area in the auxiliary storage device 903 for the data being processed according to the program.

[0114] Alternatively, programs for implementing all or part of the functions of the robot control device 10 and the driving control device 20 can be recorded on a computer-readable recording medium. The computer system can then read and execute the program recorded on this medium to perform processing based on each functional unit. Here, "computer system" includes hardware such as the operating system and supporting devices. Furthermore, if a WWW system is used, the "computer system" also includes a webpage providing environment (or display environment). "Computer-readable recording medium" refers to portable media such as CDs, DVDs, and USB drives, and storage devices such as hard drives built into the computer system. When the program is transmitted to the computer 900 via a communication line, the receiving computer 900 can expand the program to the main storage device 902 and execute the aforementioned processing. Furthermore, the program can be used to implement a portion of the aforementioned functions, and can also achieve the aforementioned functions by combining it with programs already recorded in the computer system.

[0115] <Another implementation>

[0116] The embodiments have been described in detail above with reference to the accompanying drawings, but the specific structure is not limited to the above structure, and various design changes can be made. That is, in another embodiment, the order of the above processes can be appropriately changed. Furthermore, some processes can be performed in parallel.

[0117] Furthermore, in the above embodiment, when the trolley 2 is turned, the trolley 2 is pivoted in place by means of a plurality of wheels 23 consisting of Mecanum wheels, but the trolley 2 may also have other suitable structures besides Mecanum wheels that are capable of pivoting.

[0118] Furthermore, in the above embodiment, the robotic arm 11 is configured to protrude outward when viewed from above the top plate 2t of the trolley 2, but it is not limited to this. Regarding the robotic arm 11, it can be installed on the top plate 2t at a position offset to one side relative to the center portion 2z of the top plate 2t along the width direction (first direction) of the top plate 2t on the horizontal plane.

[0119] <Postscript>

[0120] The operation robot 1 described in the implementation method and the control method of the operation robot can be understood as follows.

[0121] (1) The work robot 1 involved in the first method includes: a trolley 2 capable of traveling on the ground F; a robotic arm 11 disposed at a position offset to one side relative to the center 2z of the top plate 2t of the trolley 2 in a first direction along the horizontal plane, and capable of arbitrarily changing the position and posture of the end effector 11a; a vision sensor 12 mounted on the end effector 11a of the robotic arm 11, capable of capturing images including a marker L2 disposed at a predetermined position on the ground F; and a control device 10, the control device 10 including: a path acquisition unit 101, which acquires the path of the trolley 2 including the path Q traveled by the trolley 2 and the positions of a plurality of markers L2 disposed along the path Q. The robot 1 includes: a robotic arm control unit 105 that controls the robotic arm 11 to capture an image including the mark L2 using the vision sensor 12; and a detection unit 103 that detects the offset of the trolley 2 relative to the path Q based on the mark L2 included in the image captured by the vision sensor 12. The robot 1 also includes: a driving instruction unit 104 that instructs the trolley 2 to correct its driving position or driving posture based on the offset, and instructs the trolley 2 to drive in the direction of travel, so that the vision sensor 12 can capture an image including the mark L2 positioned relative to one side of the trolley 2 in the first direction.

[0122] The robot 1 guides the carriage 2 using a vision sensor 12 mounted on the robotic arm 11, eliminating the need for a separate mechanism for guiding the carriage 2. Therefore, it is possible to construct the carriage 2 with minimal equipment and cost, and to move the carriage 2 along the path Q with high precision. As a result, the robot 1 can be moved with a simple and low-cost structure.

[0123] Furthermore, the robotic arm 11 of the work robot 1 is positioned offset to one side relative to the center 2z of the top plate 2t of the trolley 2 in a first direction along the horizontal plane. Therefore, compared to the case where the robotic arm 11 is positioned at the center 2z of the top plate 2t, the extent to which the end point 11a of the robotic arm 11 reaches one side of the top plate 2t in the first direction is wider. Thus, even if the marker L2 moves away from the path Q of the trolley 2 in a direction intersecting the extension direction of path Q, it is easy to detect the marker L2 using the vision sensor 12. As a result, the degree of freedom in the placement of the marker L2 is increased.

[0124] Furthermore, by moving the trolley 2, an image of the mark L2, which is positioned on one side relative to the trolley 2 in the first direction, can be captured using the vision sensor 12. Thus, the mark L2 can be easily captured using the robotic arm 11, which is positioned offset to one side in the first direction relative to the center 2z of the top plate 2t of the trolley 2. Moreover, the amount of movement of the robotic arm 11 to one side in the first direction when capturing the mark L2 is also small, thereby shortening the time required for the robotic arm 11 to move and enabling efficient capture of the mark L2.

[0125] (2) The work robot 1 involved in the second method is the work robot 1 described in (1), wherein the driving instruction unit 104 instructs the trolley 2 to drive along the path Q and moves the trolley 2 sequentially to a position where the vision sensor 12 can capture each of the plurality of marks L2 arranged along the path Q, and the robotic arm control unit 105, at the position where the vision sensor 12 can capture each of the plurality of marks L2, causes the vision sensor 12 to capture an image including the mark L2.

[0126] Thus, the trolley 2 is moved sequentially to a position where it can capture images of each of the multiple markers L2 arranged along the path Q, and the vision sensor 12 captures images including the markers L2. This allows the trolley 2 to move along the path Q with high precision while correcting its driving position and posture.

[0127] (3) The work robot 1 involved in the third method is the work robot 1 described in (2), wherein the driving instruction unit 104 turns the trolley 2 when the next mark L2 arranged along the path Q is arranged on the opposite side of the mark L2 captured by the vision sensor 12 across the path Q, so that one side of the trolley 2 in the first direction is on the same side as the next mark L2 relative to the path Q.

[0128] Therefore, when the next marker L2, positioned along path Q, is located on the opposite side of a marker L2 captured by the vision sensor 12 across path Q, the trolley 2 is turned so that one side of the trolley 2 in the first direction is on the same side as the next marker L2 relative to path Q. Thus, the capture of the next marker L2 can be performed effectively.

[0129] (4) The operation robot 1 involved in the fourth method is the operation robot 1 described in (3), wherein the driving instruction 104 turns the trolley 2 at the bend Qc of the path Q that changes the travel direction of the trolley 2, so that one side of the trolley 2 in the first direction is on the same side as the next mark L2 relative to the path Q.

[0130] Therefore, the trolley 2 can be turned at the curved section Qc of the path Q that changes the direction of travel of the trolley 2, and the trolley 2 can be prevented from turning at the straight section of the path Q. Thus, it is possible to suppress collisions between a part of the working robot 1 and objects around the path Q when the trolley 2 is turned.

[0131] (5) The operation robot 1 involved in the fifth method is the operation robot 1 described in (3) or (4), wherein the robotic arm control unit 105 causes the vision sensor 12 to capture the mark L2 located at a position immediately preceding the position that causes the trolley 2 to turn on the path Q.

[0132] Therefore, by photographing the marker L2 located immediately before the position where the trolley 2 turns on path Q, the driving position and driving posture of the trolley 2 can be corrected before the trolley 2 turns.

[0133] (6) The operation robot 1 involved in the sixth method is any one of the operation robots 1 described in (3) to (5), wherein the robotic arm control unit 105 causes the vision sensor 12 to capture the mark L2 located immediately after the position that causes the trolley 2 to turn on the path Q.

[0134] Therefore, by photographing the marker L2 located immediately after the position on path Q where the trolley 2 turns, the driving position and driving posture of the trolley 2 can be corrected immediately after the trolley 2 turns.

[0135] (7) The operation robot 1 involved in the seventh method is any one of the operation robots 1 in (3) to (6), wherein the trolley 2 is capable of pivoting on the ground F, and the driving instruction 104 causes the trolley 2 to pivot at the bend Qc of the path Q.

[0136] Therefore, by pivoting the trolley 2 at the bend Qc of the path Q, it is possible to suppress collisions between a portion of the working robot 1 and objects around the path Q when the trolley 2 is turned due to the inner wheel difference, etc.

[0137] (8) The work robot 1 involved in the eighth method is any one of the work robot 1 described in (2) to (7), wherein the driving instruction unit 104 instructs the trolley 2 to stop driving when the visual sensor 12 captures an image including the mark L2 at a position where it can capture each of the plurality of marks L2.

[0138] Therefore, when capturing images including mark L2, by stopping the trolley 2, the effects of vibrations and other disturbances caused by the movement of the trolley 2 on the vision sensor 12 mounted on the end effector 11a of the robotic arm 11 can be suppressed. Thus, capturing images of mark L2 can be performed stably and reliably.

[0139] (9) The work robot 1 involved in the ninth method is the work robot 1 described in (8), wherein the robotic arm control unit 105 performs the following control: when the vision sensor 12 captures an image including the mark L2, the robotic arm 11 is extended so that when viewed from above, the end 11a of the robotic arm 11 is far away from the base 11b of the robotic arm 11; when the trolley 2 travels along the path Q, the robotic arm 11 is folded so that when viewed from above, the end 11a of the robotic arm 11 is close to the base 11b of the robotic arm 11.

[0140] Therefore, when the trolley 2 travels along path Q, by folding the robotic arm 11 so that its end 11a is close to its base when viewed from above, the centrifugal force acting on the robotic arm 11 during turning can be reduced. Thus, excessive force acting on the robotic arm 11 can be suppressed.

[0141] (10) The control method of the work robot 1 involved in the 10th method is any one of the control methods of the work robot 1 in (1) to (9), which includes: step S101, obtaining the path information of the trolley 2, the path information including the path Q of the trolley 2 and the positions of the plurality of marks L2 configured along the path Q; step S102, causing the trolley 2 to travel along the path Q; step S103, using the vision sensor 12 to capture an image including the marks L2 configured along the path Q; step S105, based on the captured image... The image contains the marker L2, and the offset of the trolley 2 relative to the path Q is detected; and in step S106, based on the offset, the trolley 2 is instructed to correct its driving position or driving posture. In step S102, when the visual sensor 12 captures an image including the marker L2, the driving direction of the trolley 2 is indicated to the trolley 2 so that the visual sensor 12 can capture an image including the marker L2 positioned on one side relative to the trolley 2 in the first direction.

[0142] Thus, the robot 1 can be moved with a simple and low-cost structure.

[0143] Industrial availability

[0144] The work robot and its control method according to the present invention enable the work robot to move with a simple and low-cost structure.

[0145] Symbol Explanation

[0146] 1-Working robot, 2-Trolley, 2a-Long side, 2t-Top plate, 2z-Central part, 10-Robot control device (control device), 11-Mechanical arm, 11a-End of arm, 11b-Base end, 12-Vision sensor, 101-Path acquisition unit, 103-Detection unit, 104-Driving instruction unit, 105-Mechanical arm control unit, D1-Path information, D2-Image, D4-Driving instruction, F-Ground, L2, L2a~L2f-Marks, Q-Path, Qc, Qc2-Bending part.

Claims

1. A work robot, comprising: The trolley is capable of moving on the ground; The robotic arm is positioned offset to one side along a first direction along the horizontal plane relative to the center of the top plate of the trolley, and can arbitrarily change the position and posture of its end effector. A vision sensor, mounted at the end of the robotic arm, is capable of capturing images including marks placed at predetermined locations on the ground; and Control device, The control device includes: The path acquisition unit acquires path information of the trolley, including the path traveled by the trolley and the positions of multiple markers configured along the path. The robotic arm control unit controls the robotic arm to capture an image including the mark using the vision sensor; The detection unit detects the offset of the trolley relative to the path based on the markings contained in the image captured by the vision sensor. and The driving instruction unit, based on the offset, instructs the trolley to correct its driving position or driving posture, and instructs the trolley to drive in the direction of travel, so as to be able to capture an image including the mark disposed on one side of the trolley relative to the first direction using the vision sensor.

2. The work robot according to claim 1, wherein, The driving instruction unit instructs the trolley to travel along the path and sequentially move the trolley to positions where the vision sensor can capture images of each of the plurality of markers arranged along the path. The robotic arm control unit enables the vision sensor to capture an image including the mark at the location where it can capture images of each of the plurality of marks.

3. The work robot according to claim 2, wherein, When the next marker, positioned along the path, is positioned on the opposite side of a marker captured by the vision sensor across the path, the driving indicator causes the trolley to turn so that one side of the trolley in the first direction is on the same side of the path as the next marker.

4. The work robot according to claim 3, wherein, The driving indicator section turns the trolley at the bend of the path that changes the trolley's direction of travel, so that one side of the trolley in the first direction is on the same side as the next marker relative to the path.

5. The work robot according to claim 3 or 4, wherein, The robotic arm control unit causes the vision sensor to capture the mark at a position immediately preceding the position where the trolley is turned on the path.

6. The work robot according to claim 3 or 4, wherein, The robotic arm control unit causes the vision sensor to capture the mark at a position immediately following the position where the trolley is turned on the path.

7. The work robot according to claim 3 or 4, wherein, The trolley is capable of pivoting on the ground. The driving indicator causes the trolley to pivot at the bends in the path.

8. The work robot according to claim 2, wherein, When the driving instruction unit uses the vision sensor to capture an image including the mark at a location where it can capture each of the multiple marks, it instructs the trolley to stop its movement.

9. The work robot according to claim 8, wherein, The robotic arm control unit performs the following controls: When the visual sensor captures an image including the mark, the robotic arm is extended so that, when viewed from above, the end of the robotic arm is away from its base. While the trolley is traveling along the path, the robotic arm is folded so that when viewed from above, the end of the robotic arm is close to the base of the robotic arm.

10. A control method for a work robot, which is the control method for a work robot according to claim 1 or 2, comprising the following steps: Obtain path information of the trolley, including the path traveled by the trolley and the positions of multiple markers configured along the path; The trolley is made to travel along the path; The visual sensor is used to capture an image including the markers arranged along the path; The offset of the trolley relative to the path is detected based on the markers contained in the captured images; and Based on the offset, the trolley is instructed to correct its driving position or driving posture. In the step of moving the trolley, while capturing an image including the mark using the vision sensor, the trolley is instructed to travel in the direction of travel so that the vision sensor can capture an image including the mark positioned on one side of the trolley relative to the first direction.

Images