Robot system, control method, article manufacturing method, program and recording medium

Abstract

To provide a technique advantageous for a mobile robot.SOLUTION: A robot system comprises: a work table; a moving cradle which is movable with respect to the work table; a robot which is mounted on the moving cradle; and a control part which controls the robot. The control part sets the robot to a first posture for starting an operation for approaching a first portion of the robot to the work table in the state that the robot is accommodated in a first area.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to robot technology. [Background technology]

[0002] Collaborative robots that work in the same space as workers are known. One use case for collaborative robots is to move a robot mounted on a mobile platform to a work site where there is a shortage of manpower, and have the robot carry out the work in place of the workers.

[0003] Patent document 1 discloses a robot system that uses a camera placed at the tip of the robot to read a mark placed on a fixed base, obtains the position of the mark, and displays the direction and amount of movement of a cart.

[0004] Furthermore, Patent Document 2 discloses a self-propelled robot that photographs a mark with a camera placed at the tip of the robot, detects errors in position and posture through image recognition, and automatically adjusts the position of the cart based on the errors. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-058142 A [Patent Document 2] JP 2010-162635 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a predetermined portion of the robot, for example the tip portion of the robot, is brought close to the workbench, there is a risk that the robot may collide with objects around the robot.

[0007] The present disclosure aims to provide technology that is advantageous for mobile robots. [Means for solving the problem]

[0008] A first aspect of the present disclosure is a robot system comprising a workbench, a mobile platform movable relative to the workbench, a robot mounted on the mobile platform, and a control unit that controls the robot, wherein the control unit sets the robot to a first posture in which, when the robot is contained in a first area, the control unit initiates an operation to bring a first portion of the robot closer to the workbench.

[0009] A second aspect of the present disclosure is a control method for a control unit that controls a robot mounted on a mobile platform that is movable relative to a workbench, characterized in that, with the robot contained in a first area, the robot is set in a first posture that initiates an operation to bring a first part of the robot closer to the workbench. Effect of the Invention

[0010] The present disclosure provides technology that is advantageous for mobile robots. [Brief description of the drawings]

[0011] [Figure 1] 1A is a perspective view of a robot system according to an embodiment, and FIG. 1B is an explanatory diagram of a robot and members attached to the robot according to the embodiment. [Diagram 2] 1A and 1B are perspective views of a robot unit according to an embodiment. [Diagram 3] FIG. 1 is a block diagram of a robot system according to an embodiment. [Figure 4] FIG. 2 is a block diagram showing a configuration of a robot unit according to the embodiment. [Diagram 5] 1A is a diagram illustrating the functions of a control unit according to an embodiment, and FIG. 1B is a diagram illustrating a robot unit according to an embodiment. [Figure 6] 10 is a flowchart for explaining a calibration operation according to the embodiment. [Figure 7]10 is a flowchart for explaining a calibration operation according to the embodiment. [Figure 8] 5A and 5B are explanatory diagrams of a calibration operation according to the embodiment. [Figure 9] 5A and 5B are explanatory diagrams of a calibration operation according to the embodiment. [Figure 10] 5A and 5B are explanatory diagrams of a calibration operation according to the embodiment. [Figure 11] 5A and 5B are explanatory diagrams of a calibration operation according to the embodiment. [Figure 12] 5A and 5B are explanatory diagrams of a calibration operation according to the embodiment. [Figure 13] FIG. 11 is an explanatory diagram of a calibration operation according to the embodiment. [Figure 14] 1A is an explanatory diagram of a first modified example of the embodiment, and FIG. 1B is an explanatory diagram of a second modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiments are illustrative of preferred configurations of the present disclosure, and for example, those skilled in the art can appropriately modify the detailed configurations without departing from the spirit of the present disclosure. In addition, in the drawings referred to in the following description of the embodiments, elements indicated by the same reference numbers have the same functions unless otherwise noted. In addition, these drawings are represented diagrammatically for convenience of illustration and explanation, and therefore shapes, sizes, arrangements, etc. may not strictly match between the drawings.

[0013] In the following embodiments, directions based on the robot are indicated by the XYZ coordinate system, which is a three-dimensional Cartesian coordinate system. The X, Y, and Z directions are mutually orthogonal. In the XYZ coordinate system, the XY plane is a horizontal plane, and the XZ and YZ planes are vertical planes. The X and Y directions are horizontal directions. The negative direction of the Z axis is the vertical direction (gravity direction), in other words, the downward direction. The positive direction of the Z axis is the upward direction. The Z direction is also the height direction.

[0014] In the following description, for example, the positive direction of the X-axis refers to the same direction as the X-axis arrow in the XYZ coordinate system, and the negative direction of the X-axis refers to the direction 180 degrees opposite to the direction of the X-axis arrow in the XYZ coordinate system. Also, when simply referring to the X-direction, it refers to the direction parallel to the X-axis, regardless of whether it is in the same direction as the X-axis arrow. The same applies to the Y-axis and Z-axis other than the X-axis.

[0015] FIG. 1(a) is a perspective view of a robot system 1000 according to an embodiment. The robot system 1000 includes a robot unit 300, a work platform 700, and a sensor. The robot unit 300 is a mobile robot. In this embodiment, the robot unit 300 is a robot that is operated and moved by an operator. The robot unit 300 includes a mobile platform 200 that is movable relative to the work platform 700, and a robot 100 mounted on the mobile platform 200. The robot 100 is, for example, an industrial robot. The work platform 700 is a platform on which the robot 100 performs a predetermined task. The work platform 700 is, for example, a fixed platform fixed to the floor of a factory or the like. The work platform 700 may also be configured to be mobile.

[0016] Fig. 1(b) is an explanatory diagram of the robot 100 according to the embodiment and members attached to the robot 100. Fig. 2(a) and Fig. 2(b) are perspective views of a robot unit 300 according to the embodiment. The sensors include an area sensor 204 and a camera 109. The area sensor 204 and / or the camera 109 are used to obtain information on the direction of at least the worktable 700 relative to the robot 100.

[0017] The robot 100 and the area sensor 204 are disposed on the upper surface of the movable platform 200. A handle 207 is attached to the movable platform 200, which an operator can grasp to operate the movable platform 200. When an operator grasps the handle 207 and moves the movable platform 200, the robot unit 300, i.e., the robot 100, can be moved to any position.

[0018] Casters 201 are attached to the underside of the movable platform 200 so that the movable platform 200 can be easily moved. This allows the worker to easily move the movable platform 200 to a position adjacent to the work platform 700. With the movable platform 200 disposed adjacent to the work platform 700, the robot 100 can perform a predetermined task on the work platform 700. The predetermined task is, for example, an assembly task of assembling a first workpiece to a second workpiece.

[0019] In addition, fixed legs 205 and movable legs 206 are arranged on the underside of the movable platform 200. The casters 201 move up and down when an operator operates a lift switch 202 of the movable platform 200. For example, an operator operates the lift switch 202 in an upward direction to retract the casters 201 upward, and the fixed legs 205 and movable legs 206 come into contact with the floor surface, thereby fixing the movable platform 200 to the floor surface so that the movable platform 200 does not move easily. In addition, for example, an operator operates the lift switch 202 in a downward direction to protrude the casters 201 downward, and lift the entire movable platform 200 upward, allowing the movable platform 200 to be easily moved by the casters 201.

[0020] The base of the robot 100 is a fixed end, and is fixed to a moving base 200. The tip of the robot 100 is a free end. That is, when the robot 100 operates, a tip portion 103, which is an example of a first portion of the robot 100, moves to an arbitrary position. The robot 100 has a robot arm 101, a robot hand 102, which is an example of an end effector, and a probe 120. In the first embodiment, the tip portion 103 of the robot 100 is the robot hand 102 or the probe 120. The robot hand 102 and the probe 120 are attached to a predetermined portion of the robot arm 101, for example, the tip portion of the robot arm 101.

[0021] The robot arm 101 is, for example, a vertical articulated robot arm. The robot arm 101 is a multi-axis, for example, six-axis, robot arm. The robot 100 is used for applications such as the manufacture of goods, or the transportation or picking of workpieces. The robot 100 may further include an end effector (not shown), or the probe 120 may be replaced with the end effector.

[0022] The robot arm 101 has six joints J1 to J6. The joint J1 is the first joint, the joint J2 is the second joint, the joint J3 is the third joint, the joint J4 is the fourth joint, the joint J5 is the fifth joint, and the joint J6 is the sixth joint. The number of joints is not limited to six, and may be, for example, seven. The robot arm 101 has a base 110 which is a fixed link, and a plurality of links 111 to 116 which are movable links. The base 110 and the links 111 to 116 are connected to each other by the joints J1 to J6 in a serial link format, so that each of the links 111 to 116 can rotate at each of the joints J1 to J6. The robot hand 102 and the probe 120 are attached to, for example, the link 116.

[0023] In this embodiment, each of the rotation axes of the joints J1, J4, and J6 is parallel (for example, coaxial) to the central axis of the two linked links. In each of the joints J1, J4, and J6, the link on the tip side of the two links torsionally rotates (pivots) around the rotation axis relative to the link on the base side. For example, the joint J1 is a joint that allows the links 111 to 116 to rotate around a rotation axis parallel to the Z axis relative to the moving platform 200 and the base 110 fixed to the moving platform 200. On the other hand, each of the rotation axes of the joints J2, J3, and J5 intersects (for example, perpendicular to) the central axis of the two linked links. In each of the joints J2, J3, and J5, the link on the tip side of the two links bends (swings) around the rotation axis relative to the link on the base side. In this way, the robot arm 101 rotates at the joints J1, J4, and J6, and bends and extends at the joints J2, J3, and J5.

[0024] A motor, a reducer, a torque sensor, and an angle sensor are disposed in each of the joints J1 to J6. The motors provided in each of the joints J1 to J6 drive the links 111 to 116 via reducers, allowing the robot 100 to assume various postures. A tool center point (TCP) is defined in the tip portion 103 of the robot 100, and the robot 100 can be operated in various postures by specifying the position and posture of the TCP. Although each of the joints J1 to J6 is a rotary joint, the present invention is not limited to this, and for example, any of the joints may be a linear joint.

[0025] The robot hand 102 is configured to be capable of holding a workpiece. In a production line for manufacturing goods, the robot 100 can grasp a workpiece with the robot hand 102 to carry it or assemble it to another workpiece, or grasp a tool to process the workpiece. Alternatively, the robot 100 can perform work by attaching an actuator other than the robot hand 102 to the link 116 instead of the robot hand 102, depending on the work content of the manufacturing process.

[0026] For example, a plurality of workpieces are arranged around the robot 100, for example on the work table 700. An article that is an assembly can be manufactured by a manufacturing method in which the robot 100 holds one workpiece and assembles the workpiece to another workpiece. The assembly can be an intermediate product or a final product.

[0027] 3 is a block diagram of a robot system 1000 according to an embodiment. The workbench 700 has a main body 751 of the workbench 700 and a jig 710 arranged on the main body 751. The jig 710 is an example of a second part. The main body 751 has a plane 752. The plane 752 is a horizontal plane. The jig 710 is positioned and arranged on the plane 752.

[0028] The robot system 1000 includes a robot controller 350, a vision controller 360, a hand controller 370, and a programmable logic controller (PLC) 380, which are arranged inside the moving platform 200. An input device 390 can be connected to the robot controller 350 and the PLC 380 by wire or wirelessly.

[0029] A unit 750 is disposed on the work table 700. The unit 750 may include a jig for fixing a workpiece, a workpiece supplying machine for supplying a workpiece, or a hand exchange table for exchanging the robot hand 102. The unit 750 and the PLC 380 can be connected to each other by wire or wirelessly.

[0030] The robot controller 350 is a device that controls the operation of the robot arm 101. The hand controller 370 is a device that controls the operation of the robot hand 102. The PLC 380 comprehensively controls the unit 750, the robot controller 350, the vision controller 360, the hand controller 370, the input device 390, and the like. The input device 450 is a device that can be operated by an operator to input various information to the robot controller 350 and the PLC 380. The input device 390 can be, for example, a teaching pendant equipped with an operation unit such as a touch panel display and buttons. The touch panel display functions as a graphical user interface (GUI).

[0031] The area sensor 204 emits energy (e.g., infrared rays, electromagnetic waves, or electromagnetic fields) and receives the energy reflected by objects surrounding the mobile platform 200. For example, the area sensor 204 emits laser light as energy. When the mobile platform 200 is moved close to the work platform 700, the work platform 700 is placed around the mobile platform 200. In this case, the surrounding object is the work platform 700. Therefore, the area sensor 204 irradiates the work platform 700 with laser light and detects the reflection of the laser light from the work platform 700.

[0032] If the mobile platform 200 or the robot 100 is about to collide with a surrounding object while the mobile platform 200 is moving, the PLC 380 can activate a brake (not shown) inside the mobile platform 200 based on the sensing result from the area sensor 204. This makes it possible to prevent the mobile platform 200 and the robot 100 from colliding with the surrounding object.

[0033] Furthermore, after the mobile platform 200 is installed, the area sensor 204 can recognize that a worker is near the robot 100, and the robot controller 350 can limit the upper limit of the motion speed of the robot 100. For example, when the robot 100 performs a task by itself, the robot controller 350 operates the robot 100 at the maximum motion speed. On the other hand, when the area sensor 204 detects an object within the motion area of ​​the robot 100 (area A2 described below), such as when the robot 100 performs a collaborative task at a close distance to a worker, the motion speed of the robot 100 is reduced below the maximum speed.

[0034] The jig 710 has a mark 711 that can be imaged by the camera 109, and a contact member 712 that serves as a contact point with which the probe 120 comes into contact. The upper surface of the contact member 712 is a cone-shaped contact surface with which the tip of the probe 120 can come into contact. The mark 711 is a mark for recognizing the position of the work table 700. The camera 109 is attached to a predetermined portion of the robot arm 101, for example, the link 116. The camera 109 is a digital camera. The camera 109 is connected to the vision controller 360. The attachment position of the camera 109 is not limited to the link 116, and may be attached to the robot hand 102, for example.

[0035] The relative positioning of the mobile platform 200 with respect to the work platform 700 may be performed by an operator aligning the fixed legs 205 and the movable legs 206 of the mobile platform 200 with marks 210 drawn on the floor around the work platform 700. The relative positioning of the mobile platform 200 with respect to the work platform 700 may also be performed by abutting the abutment pin 220 of the mobile platform 200 with the abutment base 720 of the work platform 700. The position of the mobile platform 200 with respect to the work platform 700 can be roughly adjusted.

[0036] The devices included in the unit 750 are connected by a network such as a field bus or I / O (Input / Output), and by establishing a connection with the PLC 380, they become controllable by the PLC 380. Note that the configuration is not limited to controlling the unit 750 by the PLC 380, and for example, a dedicated PLC may be placed on the workbench 700 for controlling the unit 750, and the dedicated PLC may control the unit 750.

[0037] The unit 750 and the PLC 380 hold identification information D700 such as a unique ID corresponding to the workbench 700. In other words, unique identification information D700 is assigned to the workbench 700. When establishing a connection between the unit 750 and the PLC 380, the PLC 380 identifies the workbench 700 by checking the identification information D700.

[0038] Furthermore, after the movable platform 200 is installed near the work platform 700, the movable platform 200 and the work platform 700 are connected via a network, whereby the robot controller 350 obtains identification information D700 unique to the work platform 700 from the unit 750 or the PLC 380. This enables the robot controller 350 to identify the work platform 700.

[0039] The identification information D700 may be input from an input device 390 or the like other than the network, or a mark (not shown) on the workbench 700 (a barcode such as a QR code (registered trademark), a pattern, a color, etc.) may be read by the camera 109.

[0040] 4 is a block diagram showing the configuration of a robot unit 300 according to an embodiment. The robot arm 101 has motors 151, angle sensors 150, and torque sensors 160 arranged at the joints J1 to J6. A force sensor 170 used to obtain information on a force acting on the probe 120 is configured by having a plurality of torque sensors 160, the number of which is the same as the number of joints.

[0041] The robot controller 350 is an information processing device configured with a computer. The robot controller 350 has a CPU (Central Processing Unit) 351 as a processor. The robot controller 350 also has a ROM (Read Only Memory) 352, a RAM (Random Access Memory) 353, and a HDD (Hard Disk Drive) 354 as examples of a storage unit. The robot controller 350 also has a recording disk drive 355 and an input / output interface (I / F) 356.

[0042] A ROM 352, a RAM 353, a HDD 354, a recording disk drive 355, and an interface 356 are connected to the CPU 351 via a bus 357. A basic program that is read by the CPU 351 when the computer is started is stored in the ROM 352. The RAM 353 is a storage device that temporarily stores various data such as the results of calculations performed by the CPU 351.

[0043] The HDD 354 is a storage device that stores the results of arithmetic processing by the CPU 351 and various data acquired from the outside. A program 358 for causing the CPU 351 to execute arithmetic processing is recorded in this HDD 354. The CPU 351 functions as a control unit 440 that executes a control method described below based on the program 358 recorded (stored) in the HDD 354. The recording disk drive 355 can read out various data, programs, etc. recorded in a recording disk 359.

[0044] The interface 356 is connected to the input device 390, the vision controller 360, the hand controller 370, the area sensor 204, and the servo control device 130. The CPU 351 (control unit 440) acquires input data (input information) from the input device 390 via the interface 356 and the bus 357. The control unit 440 acquires an image captured by the camera 109 from the vision controller 360 via the interface 356 and the bus 357.

[0045] The servo control device 130 is connected to a motor 151 for each joint of the robot arm 101, an angle sensor 150, and a torque sensor 160. The motor 151 is, for example, a brushless DC motor or an AC motor, and rotates and drives the corresponding joint.

[0046] The angle sensor 150 is, for example, a rotary encoder, which is provided on the motor 151, detects the rotation angle of the motor shaft of the motor 151, and outputs a signal indicating the detected encoder value to the servo control device 130. The torque sensor 160 is provided on a corresponding joint, detects the torque acting on the corresponding joint, and outputs a signal indicating the detected torque value to the servo control device 130.

[0047] The servo control device 130 takes in a signal from the torque sensor 160 at a predetermined cycle, converts it into a digital signal indicating a torque value, and outputs it to the control unit 440. The servo control device 130 also takes in an encoder signal from the angle sensor 150, counts it, and outputs the counted value to the control unit 440. The servo control device 130 may convert information on the rotation angle of the motor 151 from the angle sensor 150 into information on the angle of the corresponding joint, and output the information on the angle of the joint to the control unit 440. The control unit 440 outputs a command value to the servo control device 130 based on these detection results, and controls the operation of the robot arm 101.

[0048] The control unit 440 is also configured to recognize the direction in which the mobile platform 200 exists, using edge information of the work platform 700 detected by the area sensor 204 .

[0049] The vision controller 360 can process the captured image acquired from the camera 109 and perform image recognition. The vision controller 360 is also connected to the robot controller 350 via a network, and can transmit image-recognized position information of the mark 711 to the control unit 440, thereby correcting the position information based on the camera image.

[0050] A probe 120 is attached to the tip of the robot arm 101. The control unit 440 acquires the position of the probe 120, i.e., the position of the work table 700, by calculating forward kinematics from angle information acquired from the angle sensors 150 of the joints J1 to J6 when the probe 120 is brought into contact with the contact member 712 of the jig 710. To determine whether the probe 120 has come into contact with the contact member 712, the torque sensors 160 of the joints J1 to J6 are used.

[0051] A storage device of the robot controller 350, for example, a HDD 354, stores in advance position information on one or more types of work tables 700, for example, shape information and position information on each of the work tables 700 and the units 750 and jigs 710 mounted on the work tables 700. Furthermore, the programs 358 stored in the HDD 354 include a process operation program and a calibration operation program. The control unit 440 recognizes the arrangement of the units 750 according to the recognized type of work table 700, and switches between the process operation and the calibration operation.

[0052] The HDD 354 is also a non-transient recording medium readable by a computer. In this embodiment, the program 358 is stored in the HDD 354, but is not limited to this. The program 358 may be recorded in any recording medium as long as it is a non-transient recording medium readable by a computer. For example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a magnetic tape, or a non-volatile memory may be used as a recording medium for supplying the program 358. The optical disk is, for example, a disk medium such as a Blu-ray disk, a DVD, or a CD. The non-volatile memory is, for example, a storage device such as a USB memory, a memory card, a ROM, or an SSD. The program 358 may also be acquired via a network.

[0053] 5(a) is an explanatory diagram of the function of the control unit 440 according to the embodiment. The CPU 351 of the robot controller 350 executes the program 358 to function as the control unit 440 that controls the robot 100. The control unit 440 selectively executes a process operation mode M1 in which the robot 100 performs a manufacturing operation such as an assembly operation by controlling the operation of the robot 100, and a calibration operation mode M2 ​​in which data such as a teaching point is calibrated. The jig 710 is used in the calibration operation mode M2. The process operation mode M1 is an example of a first mode, and the calibration operation mode M2 ​​is an example of a second mode.

[0054] In the process operation mode M1, the control unit 440 acquires a plurality of teaching points, calculates trajectory data by interpolating the plurality of teaching points, and controls the six joints J1 to J6 of the robot arm 101 based on the trajectory data. The trajectory data includes a plurality of point data. Each point data in the trajectory data used to control the robot 100 may include position (angle) command data for the six joints J1 to J6.

[0055] Fig. 5(b) is an explanatory diagram of a robot unit 300 according to an embodiment. An area A2 is defined around the robot 100. The area A2 is an area through which the robot 100 can pass when the robot 100 is operated within the movable ranges of each of the joints J1 to J6 of the robot 100. The area A2 is a three-dimensional area. The area A2 is an example of a second area.

[0056] Moreover, within the area A2, an area A1 is defined. The area A1 is a narrower area than the area A2 and is included in the area A2. The area A1 is a three-dimensional area. The area A1 is an example of a first area. The area A1 is, for example, an area above the mobile platform 200. The area A1 is an area included in a range surrounded by the outline of the mobile platform 200 when the mobile platform 200 is viewed in the vertical direction. The area A1 can be considered as an area in which the robot 100 can move without colliding with objects such as other platforms and surrounding objects. In the area of ​​the area A2 other than the area A1, the work platform 700 and surrounding objects may exist. Therefore, if the robot arm 101 is extended to an area of ​​the area A2 other than the area A1 in a situation in which the position information of the robot 100 has not been determined, there is a risk that the robot 100 will collide with surrounding objects. Information on the area A1 is stored in a storage device of the robot controller 350, for example, in the HDD 354.

[0057] Figures 6 and 7 are flow charts for explaining the calibration operation according to the embodiment. Figures 8(a), 8(b), 9(a), 9(b), 10(a), 10(b), 11(a), 11(b), 12(a), 12(b), and 13 are explanatory diagrams of the calibration operation according to the embodiment.

[0058] 8(a), the worker moves the robot unit 300 to place the robot 100 near the work table 700. The control unit 440 acquires the identification information D700 of the work table 700 from the PLC 380, for example.

[0059] When the robot unit 300 is installed near the work table 700, the control unit 440 of the robot controller 350 is not aware of the positional relationship R1 between the robot 100 on the movable platform 200 and the work table 700. Therefore, the control unit 440 executes three steps, broadly classified as S1, S2, and S3, in the calibration operation mode M2.

[0060] In step S 1 , the control unit 440 recognizes the direction of the worktable 700 relative to the robot 100 .

[0061] Next, in step S2, the control unit 440 sets the posture of the robot 100 to an initial posture for starting an operation of moving the tip portion 103 of the robot 100 toward the work table 700 with the robot 100 contained within the area A1.

[0062] Next, in step S3, the control unit 440 extends the robot arm 101 from the initial posture toward the worktable 700, detects the jig 710 to obtain information on the positional relationship R1, and adjusts the operation data of the robot 100 to be used in the process operation mode M1, such as the data of the teaching points.

[0063] The processing of steps S1 to S3 will be described in detail below. In step S1, the control unit 440 uses a sensor such as the area sensor 204 or the camera 109 to search for the direction of the work platform 700 relative to the mobile platform 200. The processing of step S1 will be described in detail below.

[0064] First, in step S1-1, as shown in FIG. 8(b), the control unit 440 acquires shape information S700 of the surrounding object, i.e., the worktable 700, based on the scan result acquired by the area sensor 204 scanning the surroundings with laser light. That is, the control unit 440 acquires shape information S700 of the worktable 700 from the sensing result from the area sensor 204. The control unit 440 reads out model data SD700 of the worktable 700 from the HDD 354. The model data SD700 is shape data of a model, for example, 3D CAD data. The control unit 440 collates the shape information S700 of the worktable 700 with the model data SD700, and extracts edge information in which the shape of the worktable 700 matches part of the shape of the model, thereby recognizing the direction D0 of the worktable 700 with respect to the robot 100. The model data SD700 is linked to the identification information D700 and stored (registered) in the HDD 354. As a result, the control unit 440 reads out the model data SD700 linked to the identification information D700. In this manner, it is possible to identify the model data SD700 corresponding to the workbench 700. In this embodiment, the control unit 440 recognizes the direction D0 and distance of the workbench 700.

[0065] In this embodiment, an example has been described in which the area sensor 204 is used to recognize the direction D0 of the worktable 700, but this is not limited to this, and sensors such as the camera 109 mounted on the robot 100, a proximity sensor attached around the mobile platform 200, or an electromagnetic induction circuit may also be used.

[0066] When the camera 109 is used as the sensor, the control unit 440 acquires image information from the camera 109 by rotating the robot arm 101 around the rotation axis of the joint J1 within the area A1 while pointing the camera 109 outward in the radial direction centered on the rotation axis of the joint J1. The control unit 440 may recognize the direction D0 of the workbench 700 from position information of marks, etc. extracted based on the acquired image information and posture information of the robot arm 101.

[0067] 9(a), in step S1-2, the control unit 440 calculates the direction D1 and distance of the jig 710 of the work table 700 relative to the robot 100 based on the information obtained in step S1-1 and shape information and position information of the jig 710 on the work table 700 stored in advance in the HDD 354 or the like, and stores the calculation results in the HDD 354. Note that the storage device for storing the calculation results is not limited to the HDD 354. In this manner, the control unit 440 obtains information on the direction D1 of the jig 710 among the directions D0 of the work table 700.

[0068] In step S1-3, the control unit 440 determines whether or not the work to be performed on the workbench 700 can be performed. For example, as shown in Fig. 9(b), it determines whether or not the jig 710, workpiece, tools, and the like can fit into an area A2 indicating the movable range of the robot 100. That is, the control unit 440 determines whether or not the robot 100 can perform the assembly work on the workbench 700 based on the area A2.

[0069] If the result of the determination in step S1-3 is that the assembly work can be performed, that is, if step S1-3 is YES, the control unit 440 proceeds to the process of step S2. If the result of the determination in step S1-3 is that the assembly work cannot be performed, that is, if step S1-3 is NO, the control unit 440 proceeds to the process of step S1-4N.

[0070] In step S1-4N, the control unit 440 issues a warning. For example, the control unit 440 causes the input device 390 to display a warning. This prompts the worker to reinstall the mobile platform 200.

[0071] In step S2, the control unit 440 rotates the robot 100 so that the tip portion 103 of the robot 100 assumes an initial posture in which the tip portion 103 faces in the direction D1 of the jig 710 of the workbench 700 obtained in step S1.

[0072] The process of step S2 will be described in detail below. First, in step S2-1, as shown in Fig. 10(a), the control unit 440 determines an initial posture B1 shown in Fig. 10(b) based on information on a direction D1 of the jig 710 of the work table 700 relative to the robot 100. The initial posture B1 is an example of a first posture. The control unit 440 registers, in the HDD 354 or the like, information on the initial posture B1 of the robot arm 101 at the start of step S3 such that the robot 100 does not go out of the area A1.

[0073] 10(b), the control unit 440 operates the robot 100 with the robot 100 located within the area A1, thereby setting the attitude of the robot 100 to an initial attitude B1 at which the robot 100 starts to move the tip portion 103 of the robot 100 toward the workbench 700. In the first embodiment, the control unit 440 sets the attitude of the robot 100 to the initial attitude B1 by rotating the joint J1 of the robot arm 101 with the robot 100 located within the area A1.

[0074] The initial posture B1 is a posture of the robot 100 at which the tip portion 103 of the robot 100 starts to approach the jig 710 of the workbench 700. Therefore, when the robot 100 is in the initial posture B1, the tip portion 103 of the robot 100 faces the jig 710 as viewed in the Z direction.

[0075] In this way, the control unit 440 rotates the joint J1 of the robot arm 101 so that the posture of the robot arm 101 becomes the initial posture B1. In this case, the joint J1 of the robot arm 101 is rotated so that the robot 100 does not go out of the area A1. As a result, the tip portion 103 of the robot 100 faces the jig 710. In other words, the initial posture B1 is a posture in which the tip portion 103 of the robot 100 faces the direction D1 of the jig 710 of the work table 700 in the radial direction centered on the rotation axis parallel to the Z axis of the joint J1. By rotating the robot arm 101 within the area A1, collision of the robot 100 with surrounding objects including the work table 700 and the worker is reduced. Thus, a technology advantageous to the mobile robot 100 is provided.

[0076] Next, in step S3, the control unit 440 performs detailed position calibration for the worktable 700. The process of step S3 will be described in detail below.

[0077] First, in step S3-1, as shown in FIG. 11(a), the control unit 440 extends the robot arm 101 in the area A2 so that the tip portion 103 of the robot 100 moves toward the direction D1 of the jig 710 of the workbench 700 in the state where it has been turned in step S2, and brings the tip portion 103 of the robot 100 close to the jig 710. The posture of the robot 100 in the state where the tip portion 103 of the robot 100 is close to the jig 710 is set as posture B2. The posture B2 is an example of the second posture. In this way, the control unit 440 controls the robot 100 to change from the initial posture B1 to posture B2, and brings the tip portion 103 of the robot 100 close to the jig 710 of the workbench 700.

[0078] In this embodiment, posture B2 is a posture in which probe 120 of robot 100 is positioned at a predetermined distance in the positive direction of the Z axis from jig 710. In steps S3-2 to S3-6, control unit 440 operates robot 100 from initial posture B1 to posture B2, and then acquires position information of jig 710 relative to robot 100, and acquires positional relationship R1 based on the position information.

[0079] First, in step S3-2, as shown in Fig. 11(b), control unit 440 checks whether mark 711 of jig 710 is within viewing angle V1 of camera 109. Viewing angle V1 of camera 109 is the angle of view of camera 109. If mark 711 is within viewing angle V1 of camera 109, mark 711 is captured in the image. The orientation of camera 109 is set so that the imaging direction is in the negative direction of the Z axis.

[0080] If the mark 711 is present in the image, that is, if step S3-2 is YES, the control unit 440 proceeds to the process of step S3-3Y. If the mark 711 is not present in the image, that is, if step S3-2 is NO, the control unit 440 proceeds to the process of step S3-3N.

[0081] In steps S3-3N, the control unit 440 issues a warning. For example, the control unit 440 causes the input device 390 to display a warning. This prompts the worker to reinstall the mobile platform 200.

[0082] Mark 711 is a mark that enables acquisition of information on the relative position of jig 710 with respect to robot 100, including information on the translational position on the horizontal X-axis and Y-axis, and information on the rotational position around the Z-axis perpendicular to the horizontal plane, based on an image captured by camera 109.

[0083] In step S3-3Y, the vision controller 360 calculates the amount of deviation of the X-axis and Y-axis positions of the mark 711 based on the central axis of the camera 109 as information on the translational position of the X-axis and Y-axis based on the image captured by the camera 109, and calculates the amount of deviation of the attitude (θ) around the Z-axis as information on the rotational position around the Z-axis. That is, the vision controller 360 calculates the amount of deviation Δ of the robot 100 in the XYθ directions relative to the mark 711. The control unit 440 calculates position correction information for the robot 100 that eliminates the amount of deviation Δ. It is preferable that the mark 711 is a figure, a rectangle, or the like that allows the amount of deviation Δ of the robot 100 to be recognized.

[0084] 12(a), in step S3-4, the control unit 440 operates the robot arm 101 based on the calculated position correction information, and corrects the position and orientation of the tip of the robot 100. As a result, the probe 120 and the contact member 712 face each other in the Z direction.

[0085] Next, in step S3-5, the control unit 440 operates the robot arm 101 so that the probe 120 of the robot 100 moves in the negative direction of the Z axis, and brings the tip of the probe 120 into contact with the contact member 712. The contact member 712 is formed in a shape that allows the probe 120 to contact and acquire information on the translational position of the Z axis, which is among the relative positional information of the jig 710 with respect to the robot 100. When the control unit 440 brings the probe 120 into contact with the contact member 712, the control unit 440 operates the robot arm 101 so as to search for the bottom of the cone-shaped contact member 712 by force detection using the torque sensor 160. Then, in step S3-6, the control unit 440 calculates the amount of deviation in the Z direction, which is the height direction, as information on the translational position of the Z axis.

[0086] The control unit 440 determines information on the positional relationship R1 between the robot 100 and the worktable 700 based on the amount of deviation calculated in the above steps S3-1 to S3-5.

[0087] In step S3-7, the control unit 440 collectively updates the data of the multiple teaching points P1 to PN based on the information on the positional relationship R1, as shown in Fig. 13. The multiple teaching points P1 to PN are teaching points that define the assembly work.

[0088] Here, the teaching points P1 to PN of the robot 100 can be created in a robot coordinate system Σ1 based on the robot 100, or in a workpiece coordinate system Σ2 based on the worktable 700. The robot coordinate system Σ1 is an example of a first coordinate system. The workpiece coordinate system Σ2 is an example of a second coordinate system.

[0089] The robot coordinate system Σ1 is a three-dimensional orthogonal coordinate system based on the robot 100, for example an XYZ coordinate system having mutually orthogonal X-, Y- and Z-axes, and has an origin at the base of the robot 100. The workpiece coordinate system Σ2 is a three-dimensional orthogonal coordinate system based on the worktable 700.

[0090] When the teaching points P1 to PN are created based on the robot coordinate system Σ1, the operator needs to create the teaching points P1 to PN again every time the robot 100 is moved due to a layout change or the like.

[0091] On the other hand, in this embodiment, the teaching points P1 to PN are created based on the workpiece coordinate system Σ2. In the calibration operation mode M2, the control unit 440 updates the teaching points P1 to PN based on the workpiece coordinate system Σ2 to teaching points P1 to PN based on the robot coordinate system Σ1, based on information on the positional relationship R1 between the robot 100 and the worktable 700. Therefore, the operator does not need to create the teaching points P1 to PN again.

[0092] Then, in the process operation mode M1, the control unit 440 controls the robot 100 based on the data of the plurality of teaching points P1 to PN after the update. Specifically, in the process operation mode M1, the control unit 440 calculates trajectory data from the plurality of teaching points P1 to PN after the update. Then, the control unit 440 controls the operation of the robot 100 according to the trajectory data. In creating the trajectory data, the teaching points P1 to PN created based on the workpiece coordinate system Σ2 are converted (updated) to teaching points P1 to PN based on the robot coordinate system Σ1, and the conversion process is performed using the information on the positional relationship R1 described above.

[0093] In this embodiment, the control unit 440 specifies information on the positional relationship R1 in the calibration operation mode M2. The positional relationship R1 is a transformation matrix indicating the relationship between the robot coordinate system Σ1 and the workpiece coordinate system Σ2, for example, a coordinate transformation. Then, the control unit 440 generates updated teaching points P1 to PN based on the information on the positional relationship R1.

[0094] Thus, according to this embodiment, even if the worker installs the movable platform 200 in a position different from the designated position, or if the installation position of the movable platform 200 is changed due to a change in the layout of the work site, the posture of the robot 100 can be set to the initial posture B1 so that the robot 100 does not collide with surrounding objects.

[0095] Then, by extending the robot 100 from the initial posture B1 toward the jig 710, it is possible to reduce the collision of the robot 100 with surrounding objects. Then, by detecting the jig 710, it is possible to correct (update) the operation data of the robot 100, for example, the data of the teaching points P1 to PN, in accordance with the position of the worktable 700.

[0096] Furthermore, by extending the robot 100 in the direction of the detected jig 710, the success rate of the mark 711 falling within the viewing angle V1, which is the angle of view of the camera 109, increases. This reduces the work of the operator reinstalling the robot 100.

[0097] Furthermore, since the teaching points P1 to PN are automatically updated by the above calibration operation, the operator does not need to reset the teaching points P1 to PN, and can reduce the need for the operator to reinstall the moving platform 200.

[0098] Furthermore, since the teaching points P1 to PN are updated, it is not necessary to finely adjust the position of the moving platform 200 relative to the work platform 700 after roughly adjusting the position of the moving platform 200 relative to the work platform 700. [Variations]

[0099] Fig. 14(a) is an explanatory diagram of Modification 1 of the embodiment. As shown in Fig. 14(a), a plurality of work tables 7001, 7002 may be assigned to one robot 100. In this case, the above-mentioned calibration operation may be performed for each of the plurality of work tables 7001, 7002, or, if the plurality of work tables 7001, 7002 are positioned with high accuracy relative to each other, the calibration operation may be performed for only one of the work tables.

[0100] Fig. 14(b) is an explanatory diagram of a second modified example of the embodiment. As shown in Fig. 14(b), a plurality of robot units 300 may be arranged on one workbench 700. For example, the workbench 700 may be divided into a plurality of areas A11, A12, and A13, and the robot units 300 may be arranged corresponding to each of the plurality of areas A11, A12, and A13. Then, the calibration operation may be performed by each of the plurality of robot units 300.

[0101] Also, a single robot unit 300 may be moved to each of the areas A11 to A13 to perform a plurality of tasks in the areas A11 to A13. In this case, a calibration operation may be performed every time the robot unit 300 is moved to a corresponding area.

[0102] [Other variations] The present disclosure is not limited to the above-described embodiments, and many modifications of the embodiments are possible within the technical concept of the present disclosure. Furthermore, the effects described in the present embodiment are merely a list of the most preferable effects resulting from the embodiments of the present disclosure, and the effects of the embodiments of the present disclosure are not limited to those described in the present embodiment.

[0103] In the above embodiment, the robot arm is a vertically multi-jointed robot arm, but the present invention is not limited to this. The robot arm may be, for example, a horizontally multi-jointed robot arm, a parallel link robot arm, or an orthogonal robot. The present disclosure is also applicable to a machine that can automatically perform operations such as extension, contraction, bending, vertical movement, horizontal movement, or rotation, or a combination of these operations, based on information in a storage device provided in a control device.

[0104] (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0105] The disclosure of the above embodiments includes the following sections.

[0106] (Section 1) A workbench and A movable stand that is movable relative to the workbench; A robot mounted on the moving platform; A control unit for controlling the robot, the control unit sets the robot to a first posture in which the robot starts an operation of moving a first portion of the robot toward the workbench while the robot is accommodated in a first area; A robot system comprising:

[0107] (Section 2) the robot has a joint that is rotatable with respect to the moving platform, the control unit sets the robot to the first posture by rotating the joint with the robot accommodated in the first area. 2. The robot system according to item 1,

[0108] (Section 3) The first posture is a posture in which the first portion of the robot faces the worktable in the radial direction of the joint. 3. The robot system according to item 2,

[0109] (Section 4) the control unit controls the robot to change from the first posture to a second posture, and causes the first portion of the robot to approach the workbench; 4. The robot system according to any one of items 1 to 3,

[0110] (Section 5) The first area includes an area above the moving platform. 5. The robot system according to any one of items 1 to 4,

[0111] (Section 6) a sensor adapted to obtain at least information on the orientation of the worktable relative to the robot; The control unit determines the first posture based on information of an orientation of the worktable relative to the robot. 6. The robot system according to any one of items 1 to 5,

[0112] (Section 7) The sensor includes a sensor that irradiates energy onto the worktable and detects reflection of the energy from the worktable. Item 7. The robot system according to item 6,

[0113] (Section 8) The sensor includes a camera attached to the robot. 8. The robot system according to item 6 or 7,

[0114] (Section 9) the first posture is a posture of the robot that initiates approaching the first portion of the robot to the second portion of the worktable; The information about the orientation of the worktable relative to the robot includes information about the orientation of the second part relative to the robot. 9. The robot system according to any one of items 6 to 8,

[0115] (Section 10) the control unit acquires shape information of the work table from a sensing result from the sensor, and compares the shape information with model data of the work table to acquire information on a direction of the work table relative to the robot. 10. The robot system according to any one of items 6 to 9,

[0116] (Section 11) The workbench is provided with identification information, The control unit reads out model data associated with the identification information. Item 11. The robot system according to item 10,

[0117] (Section 12) A plurality of said work tables are provided. Item 12. The robot system according to item 11,

[0118] (Section 13) The first area is an area that is included in a second area through which the robot can pass when the robot is operated within a movable range of the robot, and is narrower than the second area. 13. The robot system according to any one of items 1 to 12,

[0119] (Section 14) The control unit is determining whether or not the robot can perform a predetermined task on the work platform based on the second area; When it is determined that the robot cannot perform the predetermined task on the work platform, a warning is issued. Item 14. The robot system according to item 13,

[0120] (Section 15) The predetermined operation is an assembly operation. Item 15. The robot system according to item 14,

[0121] (Section 16) The control unit is acquiring data of a plurality of teaching points with respect to the work table, the teaching points defining the predetermined work; updating data of the plurality of teaching points based on a relative positional relationship between the robot and the worktable; Controlling the robot based on the updated data of the plurality of teaching points. 16. The robot system according to item 14 or 15,

[0122] (Section 17) The control unit is operating the robot from the first posture to a second posture in which the first portion is brought closer to a second portion of the worktable, acquiring position information of the second portion relative to the robot, and acquiring information on the positional relationship based on the position information; Item 17. The robot system according to item 16,

[0123] (Section 18) the second portion includes a mark that enables acquisition of information on translational positions of a first axis and a second axis in a horizontal direction and information on a rotational position around a third axis perpendicular to a horizontal plane, among the position information, based on an image captured by a camera; Item 18. The robot system according to item 17,

[0124] (Section 19) the first portion comprises a probe; the second portion includes a contact member that allows the probe to come into contact with the second portion to acquire information on a translational position of a third axis perpendicular to a horizontal plane, among the position information; Item 19. The robot system according to item 17 or 18,

[0125] (Section 20) A control method for a control unit that controls a robot mounted on a movable platform that is movable relative to a workbench, comprising: With the robot accommodated in the first area, the robot is set in a first posture for starting an operation of moving a first portion of the robot toward the worktable. A control method comprising:

[0126] (Section 21) 20. A method for manufacturing an article, comprising the steps of: manufacturing an article by using the robot system according to any one of items 1 to 19.

[0127] (Section 22) Item 21. A program for causing a computer to execute the control method according to item 20.

[0128] (Section 23) Item 23. A computer-readable recording medium having the program according to item 22 recorded thereon. [Explanation of symbols]

[0129] B1...initial posture (first posture), 100...robot, 103...tip portion (first portion), 200...moving platform, 440...control portion, 700...workbench, 710...jig (second portion), 1000...robot system

Claims

1. A workbench and A movable stand that is movable relative to the workbench; A robot mounted on the moving platform; A control unit for controlling the robot, the control unit sets the robot to a first posture in which the robot starts an operation of bringing a first portion of the robot closer to the workbench when the robot is accommodated in a first area; A robot system comprising:

2. the robot has a joint that is rotatable with respect to the moving platform, the control unit sets the robot to the first posture by rotating the joint with the robot accommodated in the first area.

2. The robot system according to claim 1 .

3. the first posture is a posture in which the first portion of the robot faces the worktable in a radial direction of the joint; 3. The robot system according to claim 2.

4. the control unit controls the robot to change from the first posture to a second posture, and causes the first portion of the robot to approach the workbench; 2. The robot system according to claim 1 .

5. The first area includes an area above the moving platform, 2. The robot system according to claim 1 .

6. a sensor adapted to obtain at least information on the orientation of the worktable relative to the robot; The control unit determines the first posture based on information of a direction of the worktable relative to the robot.

2. The robot system according to claim 1 .

7. The sensor includes a sensor that irradiates energy onto the worktable and detects reflection of the energy from the worktable.

7. The robot system according to claim 6.

8. The sensor includes a camera attached to the robot.

7. The robot system according to claim 6.

9. the first pose is a pose of the robot that initiates approaching the first portion of the robot to the second portion of the worktable; the information about the orientation of the worktable relative to the robot includes information about the orientation of the second portion relative to the robot; 7. The robot system according to claim 6.

10. the control unit acquires shape information of the work table from a sensing result from the sensor, and compares the shape information with model data of the work table to acquire information on a direction of the work table relative to the robot.

7. The robot system according to claim 6.

11. The workbench is provided with identification information, The control unit reads out model data associated with the identification information. The robot system according to claim 10 .

12. A plurality of said work tables are provided. The robot system according to claim 11 .

13. the first area is included in a second area through which the robot can pass when the robot is operated within a movable range of the robot, and is narrower than the second area; 2. The robot system according to claim 1 .

14. The control unit is determining whether or not the robot is capable of performing a predetermined task on the work platform based on the second area; When it is determined that the robot cannot perform the predetermined task on the work platform, a warning is issued. The robot system according to claim 13 .

15. The predetermined operation is an assembly operation. The robot system according to claim 14 .

16. The control unit is acquiring data of a plurality of teaching points with respect to the work table, the teaching points defining the predetermined work; updating data of the plurality of teaching points based on a relative positional relationship between the robot and the worktable; Controlling the robot based on the updated data of the plurality of teaching points. The robot system according to claim 14 .

17. The control unit is operating the robot from the first posture to a second posture in which the first portion is brought closer to a second portion of the worktable, acquiring position information of the second portion relative to the robot, and acquiring information on the positional relationship based on the position information; 17. The robot system according to claim 16.

18. the second portion includes a mark that enables acquisition of information on translational positions about a first axis and a second axis in a horizontal direction and information on a rotational position about a third axis perpendicular to a horizontal plane, among the position information, based on an image captured by a camera; 20. The robot system according to claim 17 .

19. the first portion includes a probe; the second portion includes a contact member that allows the probe to come into contact with the second portion to acquire information on a translational position of a third axis perpendicular to a horizontal plane, among the position information; 20. The robot system according to claim 17 .

20. A control method for a control unit that controls a robot mounted on a movable platform that is movable relative to a workbench, comprising: With the robot accommodated in the first area, the robot is set in a first posture for starting an operation of moving a first portion of the robot toward the work table. A control method comprising:

21. A method for manufacturing an article, comprising the steps of: manufacturing an article by using the robot system according to any one of claims 1 to 19;

22. A program for causing a computer to execute the control method according to claim 20.

23. A computer-readable recording medium having the program according to claim 22 recorded thereon.

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