Robots, robot control devices, and operational robot systems

Abstract

A robot for performing a predetermined operation on an object portion of an object moved by an object moving device includes a robotic arm and a control device for controlling the robotic arm; the control device performs point-following control, which controls the robotic arm to follow the moving object at one or more points before moving a component or tool supported on the robotic arm to the start position of the operation; furthermore, after point-following control, the control device controls the robotic arm to position the component or tool at the start position of the operation and to follow the object while performing the component or tool operation.

Description

[Technical Field]

[0001] This disclosure relates to robots, robot control devices, and operational robot systems. [Previous Technology]

[0002] In the past, when components needed to be assembled onto items being transported by a handling device, it was often necessary to stop the handling device. This was especially true when precisely assembling components onto large items such as car bodies, where stopping the handling device from transporting the items was required. This could sometimes lead to a decrease in system efficiency.

[0003] On the other hand, a robot system is known to enable a robot to follow an object or the like that is moved by a transport device. See Patent Documents 1-3 for examples. (Prior Art Documents) (Patent Documents)

[0004] (Patent Document 1) Japanese Patent Application Publication No. 2011-140084 (Patent Document 2) Japanese Patent Application Publication No. 62-241684 (Patent Document 3) Japanese Patent Application Publication No. 2007-090479 [Summary of the Invention]

[0005] (The problem that this invention aims to solve)

[0006] As described above, in order to improve system efficiency, it is crucial for robots to perform operations on items that are moved by handling devices, etc. In this situation, depending on the type of item, it is sometimes ideal for the robot's front-end components, etc., not to move in a straight line to the start position of the operation. Furthermore, depending on the type of item, sometimes the robot's front-end components, etc., cannot move in a straight line to the start position of the operation. For example, straight-line movement of components, etc., may lead to contact with the item. Therefore, it is desirable for a robot, a robot control device, and an operational robot system to minimize contact between the robot's supported components or tools and the item. (Method for solving the problem)

[0007] The first embodiment of this disclosure is a robot for performing a predetermined operation on an object portion of an article moved by an article moving device, including a robotic arm and a control device for controlling the robotic arm; the control device is configured to perform pass-point following control and operation-time following control; the pass-point following control is configured to control the robotic arm to follow the moving article at each of one or more pass-points before moving a component or tool supported at the front end of the robotic arm to the operation start position of the predetermined operation; the operation-time following control is configured to control the robotic arm to position the component or tool at the operation start position after the pass-point following control, and to follow the moving article during the operation of the component or tool.

[0008] The second embodiment of this disclosure is a robot control device that controls the robotic arm of a robot to perform a predetermined operation on the object portion of an article moved by an article moving device. The control device is configured to perform pass-point following control and operation-time following control. The pass-point following control controls the robotic arm to follow the moving article at one or more pass-points before moving a component or tool supported at the front end of the robotic arm to the predetermined operation start position. The operation-time following control controls the robotic arm to position the component or tool at the operation start position after the pass-point following control and to follow the moving article during the operation of the component or tool.

[0009] A third embodiment of this disclosure is a work robot system, comprising: an item moving device for moving an item; a robot having a robotic arm; and a control device for controlling the robotic arm to perform a predetermined operation on an object portion of the item moved by the item moving device; the control device is configured to perform pass-point following control and operation-time following control; the pass-point following control is configured to control the robotic arm to follow the moving item at one or more pass-points before moving a component or tool supported at the front end of the robotic arm to a predetermined operation start position; the operation-time following control is configured to control the robotic arm to position the component or tool at the operation start position after the pass-point following control, and to perform operation-time following on the moving item using the component or tool.

Implementation Method

[0011] The work robot system 1 of the first embodiment will now be described with reference to the drawings. As shown in Figures 1 and 2, the work robot system 1 includes a transport device 2 (item moving device) for transporting an item 100 that is a work object. The work robot system 1 also includes a robot 10, a control device 20 for controlling the robot 10, and a detection device 40. The robot 10 performs a predetermined operation on the object portion 101 of the item 100 moved by the transport device 2. Furthermore, the work robot system 1 also has a first follow sensor 50 and a second follow sensor 60 mounted on the front end of the robot 10.

[0012] The detection device 40 is used to acquire data that at least determines the position of the article 100 or its object portion 101 transported by the conveying device 2. The detection device 40 can also acquire data that determines the position and orientation of the object portion 101. In the first embodiment, the object portion 101 has a plurality of holes 101a. The function of the detection device 40 can also be performed by the follow sensors 50 and 60.

[0013] The detection device 40 can use any device with the above-described functions. The detection device 40 can be, for example, a two-dimensional camera, a three-dimensional camera, a three-dimensional distance sensor, a sensor that illuminates an object to measure its shape, or a photoelectric sensor. The detection device 40 of the first embodiment has the same functions as the follow sensors 50 and 60. The detection device 40 of the first embodiment is a two-dimensional camera installed along the transport path of the transport device 2. When the object portion 101 enters a specified range of the viewing angle, the detection device 40 acquires image data of the object portion 101 and sends the image data as output to the control device 20. The detection device 40 can be a downward-facing camera or sensor, or a camera or sensor positioned horizontally, diagonally downward, or similarly.

[0014] The image data is data that can determine the position of at least one of a plurality of object parts 101. The control device 20 sometimes determines the position of the object part 101 based on the position, shape, etc., of a characteristic portion of the object in the image data. Furthermore, the control device 20 can also determine the posture of the object part 101 based on the positional relationship of the plurality of object parts 101 in the image data. The control device 20 can determine the posture of the object part 101 based on the position, shape, etc., of a characteristic portion in the image data. The characteristic portion can be a feature-rich element such as the mark M shown in FIG. 3, or a corner of the object 100.

[0015] Article 100 is not limited to a specific type of object, but as an example of the first embodiment, article 100 is the body of a car. The conveying device 2 moves article 100 in one direction by means of a drive motor 2a. In the first embodiment, the conveying device 2 moves article 100 to the right in FIG. 2. The motor 2a has an operating position detection device 2b, which sequentially detects the rotational position and rotation amount of the output shaft of the motor 2a. The operating position detection device 2b is, for example, an encoder. The detection value of the operating position detection device 2b is sent to the control device 20. The conveying device 2 may also have other components for moving article 100, such as a belt.

[0016] Furthermore, the configuration described in this specification can also be applied to the work robot system 1 that performs other operations such as processing, assembling, inspecting, and observing the item 100. As long as the item 100 can be transported by some means of movement, other robots different from robot 10 can also be used as item moving devices. In the case where the item 100 is a car body or frame, the body or frame can be moved by an engine, motor, wheels, etc., installed thereon. In this case, the engine, motor, wheels, etc., function as item moving devices. AGVs (Automated Guided Vehicles) and the like, which serve as item moving devices, can also move the item 100. Furthermore, the control device 20 can receive data on the movement path of the item 100 or the object part 101 from the control devices of other robots, cars, AGVs, sensors installed on these devices, etc. Alternatively, the control device 20 can also use image data successively obtained by the detection device 40, follow sensors 50, 60, etc., to calculate the aforementioned movement path data.

[0017] The object portion 101 is the part of the article 100 where the robotic arm 10a of the robot 10 performs a predetermined task. In the first embodiment, as a predetermined task, the robotic arm 10a uses a tool 30 to lift the component 110, and then mounts the mounting portion 111 of the component 110 onto the object portion 101. Thus, for example, a plurality of shafts 111a extending downward from the mounting portion 111 of the component 110 are respectively inserted into a plurality of holes 101a provided on the object portion 101 of the article 100. In the first embodiment, while the article 100 is continuously moved by the conveying device 2, the robotic arm 10a mounts the mounting portion 111 of the component 110 onto the object portion 101.

[0018] The robot 10 is not limited to a specific type, but the robot 10 of the first embodiment is a multi-joint robot with 6 axes. The robotic arm 10a has a plurality of servo motors 11, which drive a plurality of movable parts 12 respectively (see Figures 2 and 4). Each servo motor 11 has an operating position detection device to detect its operating position, such as an encoder. The control device 20 receives the detection value from the operating position detection device.

[0019] The robot 10 has a tool 30 mounted on its front end, which is used to transport part 110. For example, the tool 30 is a gripper, and the tool 30 is equipped with a servo motor 31 for driving the gripper (see Figure 4). The servo motor 31 has an operating position detection device for detecting its operating position, such as an encoder. The detection value of the operating position detection device is sent to the control device 20. Each servo motor 11, 31 can be a rotary motor, linear motor, or other types of servo motor.

[0020] The robot 10 has a force sensor 32 at its front end. The force sensor 32 can detect forces in the X-axis, Y-axis, and Z-axis directions, as shown in Figures 1 to 3, for example. The force sensor 32 can also detect forces around the X-axis, Y-axis, and Z-axis. As the force sensor 32, other sensors capable of detecting the direction and magnitude of forces acting on the tool 30 or the part 110 grasped by the tool 30 can be used. In the first embodiment, the force sensor 32 is disposed between the robot 10 and the tool 30. Alternatively, the force sensor 32 can also be disposed inside the tool 30, at the tail end of the robotic arm 10a, in other parts of the robotic arm 10a, or at the base of the robot 10, etc.

[0021] Follow sensors 50 and 60 are mounted on the front end of the robotic arm 10a. For example, follow sensors 50 and 60 are mounted on the wrist flange 10b of the robotic arm 10a in the same manner as tool 30. Follow sensors 50 and 60 can be two-dimensional cameras, three-dimensional cameras, three-dimensional distance sensors, etc. In the first embodiment, follow sensors 50 and 60 are two-dimensional cameras.

[0022] In the first embodiment, the first follower sensor 50 can sequentially acquire image data of the object portion 101 as shown in FIG3 when the object portion 101 enters a specific range of the viewing angle. The first follower sensors 50 and 60 can sequentially acquire image data when the objects 121, 122, and 123 enter a specific range of the viewing angle by following the objects 121, 122, and 123 by points. The follower sensors 50 and 60 sequentially transmit the image data (output) to the control device 20. The image data is data that can at least determine the position of the object portion 101 being transported by the transport device 2 and the objects 121, 122, and 123 by points. The follower sensors 50 and 60 can also acquire image data that can determine the position and posture of the object portion 101 and the objects 121, 122, and 123 by points.

[0023] In the case of multiple object parts 101, the image data is data that can determine the position of at least one of the multiple object parts 101. The control device 20 may determine the position and posture of the point-following objects 121, 122, 123, etc., based on the position, shape, etc., of the characteristic parts of the object in the image data. Furthermore, the control device 20 may determine the posture of the object parts 101, the point-following objects 121, etc., based on the positional relationship between the multiple object parts 101 and the multiple point-following objects 121 in the image data. The characteristic parts may be characteristic elements such as the mark M shown in FIG3, the corner parts of the object 100, etc.

[0024] The position and orientation of the coordinate systems of the follow sensors 50 and 60 are pre-associated with the position and orientation of the coordinate system of the robot 10 within the control device 20. For example, one of the coordinate systems of the follow sensors 50 and 60 is set as the reference coordinate system of the robot 10 operating according to the motion program 23b stored in the control device 20. The reference coordinate system may correspond to a coordinate system with the tool center point (TCP) of the tool 30 as the origin or a coordinate system with the reference position of the component 110 as the origin.

[0025] The control device 20, as shown in FIG4, includes a processor 21 comprising one or more processor elements such as a CPU or microcomputer, and a display device 22. The control device 20 has a memory unit 23, which includes non-volatile memory, ROM, RAM, etc. The control device 20 has multiple servo controllers 24 corresponding to each servo motor 11 of the robot 10 and servo controllers 25 corresponding to the servo motor 31 of the tool 30. The control device 20 also includes an input unit 26 connected by wired or wireless means. In one example, the input unit 26 is an input device such as a user-portable operation panel. In another example, the input unit 26 is a tablet computer. In the case of a tablet computer, the input is performed using touch functionality. The operation panel or tablet computer may also include the display device 22.

[0026] The memory unit 23 stores the system program 23a, which is responsible for the basic functions of the control device 20. The memory unit 23 also stores the action program 23b. The memory unit 23 also stores the approach control program 23c, the pass-through point follow control program 23d, the operation follow control program 23e, and the force control program 23f.

[0027] The control device 20 sends control commands to each servo controller 24, 25 to perform predetermined operations on the article 100 according to these programs. As a result, the robotic arm 10a and the tool 30 perform predetermined operations on the article 100. The operation of the control device 20 during this process is explained with reference to the flowchart in FIG5.

[0028] First, based on the output of the detection device 40 or the follow sensors 50 and 60, the control device 20 detects the item 100 (step S1-1). After detection, the control device 20 sends control commands to the robotic arm 10a and the tool 30 according to the proximity control program 23c (step S1-2). As a result, the robotic arm 10a moves the tool 30 from the standby position to the position of the configuration component 110, and the tool 30 grasps the component 110. The robotic arm 10a then moves the component 110 to the proximity start position 200 shown in FIG. 1.

[0029] In the first embodiment, as shown in FIG1, the approach start position 200 is located closer to the base end of the robot 10 than the boundary line BL. Furthermore, in the first embodiment, the approach start position 200 and the passing point (described later) correspond to the mounting portion 111 of the component 110. Alternatively, the approach start position 200 and the passing point may be other positions of the component 110, the front end of the robotic arm 10a, or a position corresponding to a designated position of the tool 30, etc.

[0030] Here, the position and orientation of each item 100 on the transport device 2 may deviate, for example, when each item 100 is positioned on the transport device 2. Furthermore, this deviation may occur due to vibration or the like causing each item 100 on the transport device 2 to move slightly in a direction unintended. As shown in FIG1, the item 100 may sometimes rotate about the vertical axis on the transport device 2. In this case, one end 120 of the item 100 in the X direction is positioned in the Y direction closer to the robot 10 than the object portion 101.

[0031] One end 120 can be considered a potential source of interference. In one example, the potential source of interference is located in the Y direction near the robot 10, tool 30, or component 110. In Figure 1, the rotation of the article 100 is exaggerated. The length of the article 100 is, for example, about 5 m, and the position of the article 100 in the direction of rotation about the vertical axis may deviate within a range of 2°. In this situation, the position of one end 120 in the Y direction may differ by more than 10 cm, sometimes even more than 20 cm. On top of this deviation, the positional deviation of one end 120 in the Y direction will be even greater due to the deviation in its configuration position in the Y direction.

[0032] In one example, the memory unit 23 of the control device 20 stores start position data 23g (FIG. 4) of the coordinate values ​​of the component 110 near the start position 200. That is, as shown in FIG. 1, the robotic arm 10a positions the component 110 near the start position 200 corresponding to the start position data 23g. Thus, even if the conveying device 2 moves one end 120 before the component 110 passes, the component 110 will not interfere with the end 120. In the first embodiment, interference refers to the end 120 interfering with the component 110, the robotic arm 10a, or the tool 30 before passing the component 110. The memory unit 23 of the control device 20 may also store start position data 23g of the coordinate values ​​of the tool 30 or the front end of the robotic arm 10a.

[0033] In another example, the memory unit 23 of the control device 20 stores the position data of the boundary line BL as boundary position data 23h (Fig. 4). The memory unit 23 of the control device 20 may also store data of the region AR1 where interference may occur and data of the region AR2 where interference will not occur (Fig. 4). As shown in Fig. 1, the boundary line BL is a line that separates the region AR1 where interference may occur and the region AR2 where interference will not occur from the end 120 of the moving device 2. Using the start position data 23g and / or the boundary position data 23h, the robotic arm 10a can position the component 110 close to the start position 200 without contacting the item 100.

[0034] The memory unit 23 only needs to store at least one of the start position data 23g and the boundary position data 23h. In one example, based on the user's input to the input unit 26, the control device 20 stores the start position data 23g and the boundary position data 23h in the memory unit 23. In another example, the control device 20 uses image data from the detection device 40 or the follow sensor 50 to detect or calculate the path of one end 120 of the moving part of the conveying device 2.

[0035] In one example, the aforementioned path corresponds to the boundary line BL. Then, the control device 20 sets the start position data 23g and the boundary position data 23h based on the results of the aforementioned detection or calculation. Whenever the next item 100 arrives, the control device 20 updates the start position data 23g and the boundary position data 23h. For example, when the next item 100 to be worked on arrives, the control device 20 uses image data to detect the position of one end 120. Then, using this position or the movement path data of the position and the transport device 2, the control device 20 updates the start position data 23g or the boundary position data 23h. This update prevents the component 110 from being too far from the object 101 when approaching the start position 200. Alternatively, the start position data 23g can also represent a predetermined range. In this case, the robotic arm 10a moves the component 110 to any position within the predetermined range. The setting of the first pass point 211 described below can also replace the setting of approaching the start position 200.

[0036] The control device 20 adjusts the posture of the component 110 at the approach start position 200, or the posture of the component 110 toward the approach start position 200, according to the approach pre-control program 23c, to adapt to the posture of the object part 101 (steps S1-3). In one example, the control device 20 adjusts the posture of the component 110 as the component 110 moves toward the approach start position 200, or when the component 110 reaches the approach start position 200. For example, the control device 20 uses image data from the follow sensors 50 and 60 to detect the posture of the object part 101 and adjusts the posture of the component 110 to adapt to the detected posture. The control device 20 may also be set not to execute steps S1-3.

[0037] The control device 20, according to the pass-point following control program 23d, uses the robotic arm 10a to make the component 110 follow the article 100 at the first pass-point 211 (FIG. 1) (steps S1-4). Following at the second pass-point 212 is also performed according to the pass-point following control program 23d. In the first embodiment, the position corresponding to the mounting portion 111 of the component 110 follows the component 110. Furthermore, the pass-points 211 and 212 are relative positions to the article 100. Alternatively, the tip of the robotic arm 10a, a tool 30, etc., can be used to set the component 100 to follow the article 100 at the first pass-points 211 and 212.

[0038] For this following, the control device 20 performs visual feedback, for example, using image data successively acquired by the follow sensors 50 and 60. In another example, the control device 20 performs visual feedback using data successively acquired by other cameras, other sensors, etc. Other cameras and other sensors may also be supported at the front end of other robots or fixed in designated locations. Other cameras and other sensors may also be supported on sliders that can be moved by the transport device 2 along the transport direction. Depending on the type, shape, etc., of the object part 101, the follow sensors 50 and 60, other cameras, and other sensors may be three-dimensional cameras or three-dimensional distance sensors.

[0039] Known visual feedback can be used for the above-described control. In the first embodiment, as visual feedback control, one of the following two controls can be used, for example. In both controls, the control device 20 detects at least the position of the object 121 that is being followed by the point, and causes the component 110 to follow the article 100 based on the detected position. The control of the control device 20 is also applicable to the case where the component 110 follows the article 100 based on the position of the objects 122, 123, object part 101, etc. that are being followed by the point.

[0040] The movement path of the article 100 moved by the conveying device 2 may not be a straight line. Furthermore, the posture of the article 100 on the conveying device 2 may gradually change due to vibration, etc. In these cases, the control device 20 can also make the posture of the component 110 follow the posture of the object part 101 in steps S1-4 and the following steps S1-5. In particular, making the posture of the component 110 follow the posture of the object part 101 in steps S1-5 is useful for ensuring smooth operation of the robotic arm 10a on the object part 101.

[0041] The first control method involves keeping the follower object always positioned within a specified location in the field of view of the follower sensors 50 and 60, thereby controlling the component 110 to follow the item 100. In the second control method, the position (relative to the robot 10) of the follower object within the item 100 in the coordinate system is detected. Then, the second control method uses the detected position of the follower object to correct the motion program 23b, thereby causing the component 110 to follow the item 100. The follower objects include point-following objects 121, 122, and 123, as well as the object part 101, etc.

[0042] In the first type of control, the control device 20 detects feature portions on image data successively acquired by the first follower sensors 50 and 60. Feature portions include the overall shape of the object portion 101, the hole 101a of the object portion 101, and the mark M (Fig. 3) provided on the object portion 101. The overall shape of the passing points of the article 100 following the objects 121, 122, and 123 are also considered feature portions.

[0043] The control device 20 keeps the feature portion always positioned at a predetermined location in the image data, within a reference shape and size range. The control device 20 sends control commands to the servo controller 24 for this purpose. Thus, the control device 20 enables the component 110 to follow the position and posture of the feature portion. When the follow sensors 50 and 60 are a 3D camera, a 3D distance sensor, etc., the control device 20 keeps the feature portion always positioned at a predetermined location in the 3D image data, within a reference posture. That is, the control device 20 sends control commands to the servo controller 24 for this purpose.

[0044] In the second type of control, the control device 20 uses image data successively obtained by the follower sensors 50, 60, etc., to detect the actual position of the feature part in the coordinate system of the robot 10. Then, the control device 20 corrects the teaching point of the motion program 23b according to the difference between the feature part position preset in the motion program 23b and the actual position of the feature part.

[0045] In one example, in order to perform steps S1-4, the control device 20 always positions the position of the object 121 followed by the first pass point obtained using the second follow sensor 60 at a predetermined position on the image data. Thus, the control device 20 causes the component 110 to follow the article 100 at the first pass point 211. When steps S1-4 begin, for example in FIG. 1, the position of the shaft 111a (relative to the article 100) moves from a position close to the starting position 200 to the first pass point 211.

[0046] Next, the control device 20 causes the robotic arm 10a to allow the component 110 to follow the article 100 at the second pass point 212 (steps S1-5). To perform step S1-5, the control device 20 always positions the position of the second pass point followed object 122 obtained using the second follow sensor 60 at a predetermined position on the image data. Alternatively, to perform step S1-5, the control device 20 always positions the position of the third pass point followed object 123 obtained using the first follow sensor 50 at a predetermined position on the image data. The control device 20 may also cause the component 110 to follow both pass point followed objects 122 and 123. The pass point following control at each pass point 211, 212 terminates when the matching degree between the images successively obtained by the follow sensors 50, 60 and the teaching images exceeds a predetermined standard. For example, when the matching degree at the first pass point 211 exceeds the predetermined standard, the control device 20 terminates the following at the first pass point 211. Then, the control device 20 switches to the following control operation at the second pass point 122. In one example, the pass-through control time for each pass-through point 211, 212 is from 0.1 seconds to several seconds. The pass-through control time may also be shorter than the above time. In addition, the pass-through control time, distance, etc. of each pass-through point 211, 212 can be arbitrarily set.

[0047] Next, the control device 20 moves the shaft 111a of the component 110 to the operation start position 220 of the target part 101 according to the operation follow control program 23e (step S1-6). The control device 20 uses the aforementioned visual feedback and image data from the follow sensors 50 and 60 to execute step S1-5. In other examples, when executing step S1-6, the control device 20 moves the component 110 toward the target part 101 a predetermined distance using the robotic arm 10a. When executing step S1-6, the control device 20 can use data from other cameras or other sensors while using the robotic arm 10a to bring the component 110 closer to the target part 101. At this time, the control device 20 can use visual feedback to make the posture of the component 110 approaching the target part 101 follow the posture of the target part 101.

[0048] Controlled by the robotic arm 10a in steps S1-6, the component 110 reaches the position and posture required for engagement with the object part 101. As a result, the object part 101 appears within the field of view of the first follow sensor 50. Then, when the distance between the mounting part 111 and the object part 101 is within a reference value range (step S1-7), the control device 20 begins operation-time follow control (step S1-8). Furthermore, the control device 20 begins engagement control to engage the mounting part 111 with the object part 101 according to the action program 23b (step S1-9).

[0049] The control device 20 causes the component 110 to follow the object part 101 according to the operation follow control program 23e to execute steps S1-8. Furthermore, the detection results of the second follow sensor 60, the other cameras or other sensors mentioned above can make the judgment in steps S1-7 more accurate.

[0050] Ideally, the control device 20 will use the feature portion seen from the follow sensor 50 during the fitting process for follow control when performing steps S1-8. Also, when the feature portion used for follow control is not seen from the follow sensors 50 and 60, the control device 20 may change the feature portion used for follow control.

[0051] In this controlled state, the control device 20 initiates force control based on the force control program 23f (steps S1-10). In steps S1-10, known force control methods can be used. In the first embodiment, according to the control of the control device 20, the robotic arm 10a moves the component 110 in a direction away from the force detected by the force sensor 32. The control device 20 determines the amount of movement based on the detection value of the force sensor 32.

[0052] For example, after the engagement control begins, the force sensor 32 may detect a force opposite to the direction of movement of the transport device 2. At this time, while performing the operation, the control device 20 follows the control and, based on the detection value of the force sensor 32, moves the component 110 in the opposite direction to the direction of movement of the transport device 2. Furthermore, when the force sensor 32 detects a force higher than a reference value, the control device 20 will execute an abnormal response action.

[0053] On the other hand, the control device 20 determines whether the interlocking operation is completed (steps S1-11). If the interlocking operation is completed, it sends control commands to the robotic arm 10a and the tool 30 (steps S1-12). In this way, the tool 30 is separated from the component 110, and the robotic arm 10a moves the tool 30 to the waiting position or the position where the next component 110 is stored.

[0054] In the first embodiment, the position of the mounting part 111 will pass through the first passing point 211 and the second passing point 212 between the approach start position 200 and the operation start position 220. Furthermore, at the first passing point 211 and the second passing point 212, the position of the mounting part 111 follows the article 100 transported by the conveying device 2. If the first passing point 211 and the second passing point 212 are not set, the position of the mounting part 111 will move from the approach start position 200 to the operation start position 220, for example, in a straight line. The first embodiment is useful in cases where the part 110 may come into contact with the article 100 during this straight-line movement, because it allows for following at the aforementioned passing points 211 and 212. Furthermore, using two following sensors 50 and 60, even two-dimensional sensors, it is possible to follow the movement of the article 100 in the X, Y, and Z directions.

[0055] Under certain conditions, the conveying speed of the conveying device 2 may change. Alternatively, when the detection device 40 detects the item 100, the position of the item 100 relative to the detection device 40 may not be completely fixed. The latter may be affected by factors such as the cycle time of the control device 20 processing the image of the detection device 40. In these cases, performing the aforementioned linear movement some time after the detection device 40 detects the item 100 may also lead to contact between the component 110 and the item 100. In this case, setting the following at the aforementioned pass points 211 and 212 is also useful.

[0056] Alternatively, there may be a case where only a single follower sensor 50 is provided instead of a follower sensor 60. In this case, as described above, the position of the shaft 111a can still follow the transported item 100 at the first pass point 211 and the second pass point 212.

[0057] The method and configuration for setting the following at the aforementioned points 211 and 212 will be described below. Users can make these settings by, for example, inputting into the input unit 26. The input unit 26 can be an operation panel, a tablet computer, a remote control with a joystick, etc., and the input can be made using a touch screen, a joystick, etc.

[0058] The input unit 26 has a display device 22 capable of displaying multiple screens for teaching the movement of the robotic arm 10a. One of the screens is a teaching screen for setting the movement path of the front end of the robotic arm 10a and the predetermined position of the tool 30. An example of such a teaching screen is a known teaching screen that allows the user to teach multiple teaching points. The user may teach the multiple teaching points by inputting coordinate values. The user may also teach the multiple teaching points by making predetermined inputs to the input unit 26 while moving the front end of the robotic arm 10a to multiple arbitrary positions. In this case, the methods of moving the robotic arm 10a include the aforementioned joystick operation, operation panel operation, and known methods such as the user applying force to move the front end of the robotic arm 10a.

[0059] In the first embodiment, the waiting position, the position of the configuration part 110, or the proximity to the start position 200, etc., are used as teaching points for instruction. Among the various screens described above, at least one is a teaching screen 300 (FIG. 6) for teaching the following object at passing points 211 and 212. In the passing point teaching screen 300 exemplified in FIG. 6, the user is instructed on the following object to be followed at each passing point 211 and 212. Hereinafter, an example of the processing of the control device 20 for teaching the following object will be described with reference to FIG. 7. Generally, the user uses a stationary item 100 on a stopped transport device 2 for the following instruction. On the other hand, the following instruction may also be performed when the transport device 2 is moving the item 100.

[0060] For example, the user positions the front end of the robotic arm 10a in any position and posture, and then, in this state, the user makes a first input to the input unit 26 to set the pass point. Based on the first input, the control device 20 causes each follower sensor 50, 60 to acquire an image at that position and posture (step S2-1). Then, the user makes a second input to the input unit 26 to set the pass point. Based on the second input, the control device 20 determines the follower object on the acquired image (step S2-3). The user actually places the robotic arm 10a, tool 30, and component 110 on the item 100, and the control device 20 sets the follower object based on the acquired image. This configuration is useful for preventing contact and improving work efficiency. In addition, the control device 20 may set the first pass point 211 to be close to the starting position 200.

[0061] Before the second input, the control device 20 displays one or more indicator graphics 410 on the acquisition image 400 as shown in FIG. 6 (step S2-2). Alternatively, the acquisition image 400 may be a magnified image of a portion of the images from the follow sensors 50 and 60, as shown in FIG. 6. Each indicator graphic 410 is used to display a portion of the acquisition image 400 that can be set as a follow object, or to display a feature shape, etc., on the acquisition image 400. Instead of the indicator graphics 410 in FIG. 6, indicator graphics that make the outer edge, interior, etc., of the feature shape prominent may also be displayed. In a setting where the feature shape pointed to by the cursor is prominently displayed, the cursor also functions as an indicator graphic.

[0062] The user performs the movement, resizing, etc. of the indicator graphic 410 as part of the second input. Alternatively, the user selects any one or more of the multiple indicator graphics 410 as the second input. The feature shape set by the second input will become the point-following object 121, 122, 123, etc. Furthermore, if the control device 20 automatically sets the feature shape on the acquired image 400 as a point-following object, the control device 20 does not perform the above-mentioned processing of the second input.

[0063] Then, the user makes a third input to set the passpoint at the input unit 26. Based on the third input, the control device 20 sets the follower sensors 50 and 60 used at each passpoint 211, 212. The passpoint teaching screen 300 has a sensor selection display 420 for selecting or displaying whether each follower sensor 50 and 60 is used at each passpoint 211, 212. The control device 20 sets the follower sensor selected based on the third input as the follower sensor used for passpoint following (steps S2-4). In the first embodiment, the user makes the third input using the checkbox belonging to the sensor selection display 420. In addition, if the follower sensor to be used is predetermined, or only a single follower sensor 50 is provided, the control device 20 does not perform the above processing on the third input.

[0064] Furthermore, the user makes a fourth input for setting the passpoints at the input unit 26. Based on the fourth input, the control device 20 sets the following direction for each passpoint 211, 212 (steps S2-5). More specifically, the control device 20 sets the following direction based on the input from the input unit 26. The passpoint teaching screen 300 has a direction selection display 430 for setting the following direction at each passpoint 211, 212, applicable to each of the plurality of follow sensors 50, 60. The control device 20 sets the direction selected based on the fourth input as the following direction for each passpoint 211, 212. Alternatively, if the following direction has already been determined, or if the control device 20 automatically sets the following direction, the control device 20 does not perform the above processing for the fourth input.

[0065] With the above configuration, the user can set whether each follower sensor 50, 60 is used or not, and can easily set the follower direction. When changing the setting of the direction selection display 430, the user can also perform a test operation to move the robotic arm 10a using the follower control. This configuration is useful for preventing contact and improving work efficiency.

[0066] Figure 6 shows that at the first pass point, only the image of the second follow sensor 60 is used for follow control in the X direction. For the second pass point 122, Figure 6 also shows that the image of the first follow sensor 50 is used for follow control in the X and Y directions, and the image of the second follow sensor 60 is used for follow control in the Z direction.

[0067] The above-described configuration of the first embodiment is a useful aid for teach-and-go tracking control at each passpoint 211, 212. Furthermore, the above configuration allows selection of the follower sensors 50, 60 at each passpoint 211, 212, which is also a useful aid for accurately performing follow-up and robot movements at each passpoint 211, 212. Moreover, the above configuration allows setting the direction of each follower sensor 50, 60 at each passpoint 211, 212, which is also a useful aid for accurately performing follow-up and robot movements at each passpoint 211, 212. Furthermore, the passpoint teaching screen 300 displays the setting status of the follower object as described above. This configuration is useful for users to accurately and easily identify the presence or absence of passpoint settings and the setting status of each passpoint.

[0068] One of the aforementioned screens is a teaching screen for teaching the follow-up during operation at the operation start position 220. As a teaching screen, a known teaching screen can be used, and visual feedback is used to make the shaft 111a of component 110 follow the object 101. For example, the user places the robotic arm 10a at the operation start position 220, and then at that position, the control device 20 uses the first follow sensor 50 to acquire an image of the object 101. In one example, this acquisition occurs when the user makes a specified input to the input unit 26. The control device 20 sets the feature shape in the acquired image as the follow-up object, and then uses the follow-up object to perform the aforementioned operation-time follow-up control.

[0069] When the robotic arm 10a moves to each of the passing points 211 and 212, the control device 20 may move the front end of the robotic arm 10a in a specified direction according to the motion program 23b. For example, in FIG1, when moving from passing point 211 to passing point 212, the control device 20 may move the component 110 along the Y direction according to the motion program 23b. At this time, the user can cancel the Y direction specification of the direction selection display 430 of the first follow sensor 50 related to the second passing point in the passing point teaching screen 300 of FIG6. With this setting, for the second passing point, the control device 20 will not make the component 110 follow the item 100 along the Y direction. When the motion control and follow control generated by the control command of the motion program 23b are in the same direction, the movement of the robotic arm 10a may become unsmooth due to overshoot or other reasons. The above configuration is useful for reducing or eliminating this problem.

[0070] Unlike Figure 1, Figures 8 and 9 depict cases involving different passpoints 211' and 212'. In the example of Figure 9, passpoints 211' and 212' do not follow in the Z direction. When approaching the start position 200, which is higher than the start position 220, the Z-direction positions of passpoints 211' and 212' will also be higher than the start position 220. In Figure 8, the X-direction and Y-direction positions of the second passpoint 212' are slightly offset from the start position 220, but they can also be consistent. In this case, the follower of the start position 220 can be used as the follower of the second passpoint 212'. This configuration is useful for reducing the user's teaching tasks.

[0071] The second embodiment of the work robot system will be described here, referring to FIG10. The second embodiment is similar to the first embodiment, except that the part 130 grasped by the tool 30 is a steering wheel, and the object part 101' is a steering wheel mounting part. In the second embodiment, the same components as in the first embodiment are assigned the same codes, and the description of the same components and the same effects produced by these components is omitted.

[0072] In the second embodiment, at least one of the plurality of pass points 231, 232 is located inside the article 100. In the second embodiment, the central portion of component 130 is a mounting portion installed on the object portion 101', and the central portion of component 130 follows component 110 at each pass point 231, 232 and the operation start position 240.

[0073] For example, the first pass point 231 is set on the outside of the article 100, while the second pass point 232 is set on the inside of the article 100. At the second pass point 232, a gear lever or the like can be used as a follower. In the second embodiment, if the component 130 moves in a straight line from the approach start position 200' to the work start position 240, the component 130 will inevitably come into contact with the article 100. Even in this case, the second embodiment, which has the same composition as the first embodiment, can easily install the component 130 without contact.

[0074] In the third embodiment, we will describe the contents related to the work robot system, referring to Figures 11 to 14. In the third embodiment, the follower sensors 50 and 60 in the first embodiment are replaced by a first follower sensor 50' fixed at a designated position. In this embodiment, the follower sensor 50' is supported using a known frame 51 or the like.

[0075] The placement position and support structure of the follow sensor 50' are arbitrary. In this embodiment, the follow sensor 50' is placed above the article 100. The follow sensor 50' can be supported by other robots or by a known linear guide rail that can move along the transport direction of the transport device 2. The follow sensor 50' can also be supported by other methods. In the second embodiment, the same configuration as in the first embodiment uses the same code, and the description of the same effects caused by the configuration is omitted.

[0076] The follower sensor 50' can be, for example, a 3D camera, a 3D distance sensor, etc. The position and orientation of the coordinate system of the follower sensor 50' and the position and orientation of the coordinate system of the robot 10 are pre-associated within the control device 20. In the third embodiment, for example, the waiting position, the placement position of the part 110, the approach start position 200, etc., are taught as the teaching points. The pass-point teaching screen 300' of the third embodiment may be slightly different from that of the first embodiment, as shown in FIG13. In the pass-point teaching screen 300' exemplified in FIG13, the user teaches the object to be followed at each pass-point 211, 212 (FIG. 12). Hereinafter, an example of the processing performed by the control device 20 for teaching the object to be followed will be described, with reference to FIG14.

[0077] The control device 20 requests the user to teach the object being followed via a point-based teaching screen 300' and a built-in known speech generation device. The user places the front end of the robotic arm 10a in any position and posture. In this state, the user makes the first input via point setting at the input unit 26. Based on the first input, the control device 20 causes the follow sensor 50' to acquire images in the aforementioned position and posture (step S3-1).

[0078] The control device 20 displays one or more indicator graphics 410 in the acquisition image 400 of FIG13, similar to the first embodiment (step S3-2). The user makes a second input for setting the pass point at the input unit 26. Based on the second input, the control device 20 determines the follow object on the acquisition image (step S3-3). The follow object of the first pass point 211 in FIG13 is the object part 101, but other parts 123 of the item 100, etc., can be regarded as follow objects that are convenient to follow by the pass point.

[0079] Next, the user makes a third and fourth input via point setting at the input unit 26, as in the first embodiment, and performs the same processing as in the first embodiment (steps S3-4, S3-5). Furthermore, since there is only one follower sensor in this embodiment, step S3-3 is unnecessary; however, step S3-3 is useful when there are two or more follower sensors. Additionally, by using two two-dimensional cameras facing the same direction as the follower sensors 50 and 60 instead of the follower sensor 50' that acquires the three-dimensional image, the two-dimensional cameras can achieve three-dimensional detection.

[0080] Next, the control device 20 requests instructions from the user regarding the relative position and posture of the object to be followed and the part to be followed via the point teaching screen 300' and the aforementioned voice generation device. The user places the front end of the robotic arm 10a in any position and posture corresponding to the first point 211, and in this state, makes the fifth input for setting the point to be followed in the input unit 26.

[0081] Based on the fifth input, the control device 20 causes the follower sensor 50' to acquire an image at the aforementioned position and posture (step S3-6). The acquired image shows the relative positions of the object to be followed and the parts on the component 110 that should be followed. In this embodiment, the component 110 and its mounting portion 111, etc., are the parts that should be followed. The control device 20 stores the acquired image as a reference image in the memory unit 23 (step S3-7). Alternatively, regarding step S3-1, the control device 20 may also require that the acquired image includes the object to be followed and the parts that should be followed. In this case, step S3-6 will not be executed, and step S3-7 will be executed instead.

[0082] Before the control device 20 completes the above settings at all passing points, steps S3-1 to S3-6 (step S3-8) are repeated. In the third embodiment, for each passing point 211, 212, the control device 20 will perform visual feedback, for example, using image data successively obtained by the follow sensors 50, 60. Known visual feedback can be used for the above control, but in the third embodiment, the control device 20 will perform the following follow control.

[0083] Within the viewing angle range of the follow sensor 50', the control device 20 positions the object to be followed and the part to be followed at a position that aligns their relative positions with the reference image within a predetermined reference. Furthermore, within the aforementioned viewing angle range, the control device 20 can also position the object to be followed and the part to be followed at a position that aligns their relative posture with the reference image within a range exceeding the predetermined reference. Through this visual feedback, the mounting portion 111 of the component 110 follows the object portion 101 of the article 100.

[0084] In the third embodiment, the control device 20 performs point-to-point following based on the relative position of the object to be followed and the part to be followed, as seen from the follower sensor 50' fixed outside the robotic arm 10a. Tools 30 and the like may obstruct the detection of the object to be followed within the field of view of the follower sensor mounted at the front end of the robotic arm 10a. The third embodiment has a higher degree of freedom in configuring the follower sensor 50', which helps to reduce the aforementioned detection obstacles.

[0085] Furthermore, in the third embodiment, the settings for the followable object and the settings for the object to be followed are displayed on the point teaching screen 300'. This configuration is useful for users to accurately and easily identify whether the point settings exist and the status of each point setting.

[0086] The linear movement of component 110 from the approach start position 200 to the work start position may result in contact with the item 100 by the robotic arm 10a, tool 30, component 110, etc. Furthermore, as in the second embodiment, when component 110 moves linearly from the approach start position 200 to the work start position, component 110 may always come into contact with the item 100. In the above embodiments, the robotic arm 10a can perform pass-point following at multiple pass-points before moving component 110 to the work start position. Due to this configuration, the user can make various custom settings to prevent the aforementioned contact. Also, the robotic arm 10a may perform pass-point following at a single pass-point before moving component 110 to the work start position. In this case, the effects of the above embodiments can still be achieved.

[0087] Although in the above embodiments the robotic arm 10a causes the component 110 to follow the article 100, similarly, in the above embodiments the robotic arm 10a can also cause the tool 30 to follow the article 100. This configuration can also produce the same effect as in the above embodiments. The tool 30 can perform various known operations, such as welding, assembly processing, and shaping operations required for a portion of the article 100, such as applying sealant.

[0088] Furthermore, the control device 20 of the first embodiment can perform point-to-point following based on the relative position of the object to be followed and the part to be followed, just like in the third embodiment. In this case, even in the first embodiment, the memory unit 23 stores a reference image.

[0089] The embodiments disclosed herein have been described in detail, but this disclosure is not limited to the various embodiments described above. Various additions, substitutions, modifications, and partial deletions can be made to these embodiments without departing from the spirit and intent of the invention as described in the patent application and its equivalents. For example, in the above embodiments, the order of actions and processes can be changed, and some actions or processes can be omitted or added based on conditions, without being limited to the examples described above. The same applies when the above embodiments are described using numerical values ​​or formulas. [Simplified Explanation of the Diagram]

[0010] [Figure 1] is a schematic top view of the robot system of the first embodiment. [Figure 2] is a schematic side view of the robot system of the first embodiment. [Figure 3] shows an example of image data obtained by the sensor of the robot system of the first embodiment. [Figure 4] is a block diagram of the control device of the robot system of the first embodiment. [Figure 5] is a flowchart of an example of the processing performed by the control device of the robot system of the first embodiment. [Figure 6] is an example of the screen of the display device of the robot system of the first embodiment. [Figure 7] is a flowchart of an example of the processing performed by the control device of the robot system of the first embodiment. [Figure 8] is a schematic top view of the robot system of the first embodiment. [Figure 9] is an example of the screen of the display device of the robot system of the first embodiment. [Figure 10] is a schematic top view of the robot system of the second embodiment. [Figure 11] is a schematic side view of the robot system of the third embodiment. [Figure 12] is a schematic top view of the robot system of the third embodiment. [Figure 13] is an example of the screen of the display device of the robot system of the third embodiment. [Figure 14] is a flowchart illustrating an example of processing performed by the control device of the work robot system of the third embodiment.

Claims

1. A robot for performing a predetermined operation on an object portion of an article moved by an article moving device, comprising a robotic arm and a control device for controlling the robotic arm; the control device being configured to perform a pass-through point following control and a work-time following control; the pass-through point following control being configured to control the robotic arm to follow the moving article at each of one or more pass-through points before moving a component or tool supported at the front end of the robotic arm to a work start position of the predetermined operation; the work-time following control being configured to control the robotic arm to position the component or tool at the work start position after the pass-through point following control, and to follow the moving article at the work-time position of the component or tool.

2. The robot as described in claim 1, wherein, The control device is configured to use visual feedback to perform the pass-through point following control.

3. The robot as described in claim 1 or 2, wherein, The control device is configured to follow control when performing the task using visual feedback; the follow object used by the follow control during the task is applied to the pass point among the one or more pass points that is closest to the start position of the task.

4. The robot as described in claim 1 or 2, wherein, The control device stores an action program for causing the robotic arm to perform a predetermined action; when the control device moves the component or tool in a predetermined direction and performs the following action according to the action program, it will not cause the component or tool to follow the object in that predetermined direction.

5. The robot as described in claim 1 or 2, further comprising: A display device that can display teaching screens for teaching the follower at each of the one or more pass points; And an input section for inputting the teaching that is being followed.

6. The robot as described in claim 5, wherein, The display device can display a screen for specifying a direction for performing the following at each of the one or more pass points; the control device at each pass point causes the robotic arm to perform the following in the specified direction.

7. A robot control device for controlling a robotic arm of a robot to perform a predetermined operation on an object portion of an article moved by an article moving device; the control device is configured to perform a pass-through point following control and a work-time following control; the pass-through point following control is configured to control the robotic arm to follow the moving article at each of one or more pass-through points before moving a component or tool supported at the front end of the robotic arm to a work start position of the predetermined operation; the work-time following control is configured to control the robotic arm to position the component or tool at the work start position after the pass-through point following control, and to follow the moving article at the work-time position of the component or tool.

8. The control device as described in claim 7, further comprising: A display device that can display teaching screens for teaching the follower at each of the one or more pass points; And an input section for inputting the teaching that is being followed.

9. The control device as described in claim 8, wherein, The display device can display a screen for specifying a direction for performing the following at each of the one or more pass points; the control device at each pass point causes the robotic arm to perform the following in the specified direction.

10. A work robot system, comprising: An item moving device for moving an item; a robot having a robotic arm; and a control device for controlling the robotic arm to perform a predetermined operation on an object portion of the item moved by the item moving device; the control device is configured to perform a pass-through point following control and an operation-time following control; the pass-through point following control is configured to control the robotic arm to follow the moving item at each of one or more pass-through points before moving a component or tool supported at the front end of the robotic arm to an operation start position of the predetermined operation; the operation-time following control is configured to control the robotic arm to position the component or tool at the operation start position after the pass-through point following control, and to follow the moving item at the operation-time following position of the component or tool.

11. The work robot system as described in claim 10, wherein, The control device stores an action program for causing the robotic arm to perform a predetermined action; when the control device moves the component or tool in a predetermined direction and performs the following action according to the action program, it will not cause the component or tool to follow the object in that predetermined direction.

12. The work robot system as described in claim 10 or 11 further includes: A display device that can display teaching screens for teaching the follower at each of the one or more pass points; The system includes an input unit for teaching the follower on the pass-through point teaching screen; the control device is configured to perform the pass-through point follow control using visual feedback based on the output of a sensor; the control device is configured to perform an image acquisition process and a follower object setting process; the image acquisition process is to enable the sensor to acquire an image based on the input of the input unit, given that the robotic arm is positioned at the position corresponding to one or more pass-through points; the follower object setting process is to set part or all of the object appearing in the acquired image as a follower object through the pass-through point follow control.

13. The work robot system as described in claim 12, wherein, The control device controls the robotic arm to ensure that the relative position between the object being followed and the part or tool to be followed is consistent within a predetermined reference in the images obtained successively by the sensor through point-following control.

Images