Robot, robot system, and robot operation method

Abstract

A robot (6) is provided with: a robot hand (6a) attached to the tip of a robot arm (6c); and a control unit that controls the operation of each of the robot arm (6c) and the robot hand (6a) so as to perform work on the object (3). The robot hand (6a) has a force sensor (20). The control unit controls the operation of the robot arm (6c) such that position information and orientation information of the object (3) are detected by the force sensor (20) by pressing a part of the robot hand (6a) against the object (3).

Description

[0001] Related Applications

[0002] This application claims the benefit of Japanese Patent Application No. 2022-106158, filed on June 30, 2022, and this application is incorporated herein by reference in its entirety as a part of this application. Technical Field

[0003] The present disclosure relates to a robot, a robot system, and a robot operation method, and for example, to a technology capable of automating various operations such as component replacement and assembly operations. Background Art

[0004] A variety of techniques for performing various operations using robots have been proposed (for example, see Patent Document 1). Figure 1 As shown, a gripping portion 7 for detachably gripping the grinder 3 is provided at the front end of the robot arm 6. The grinder 3 is mounted on the turntable 2. A moving mechanism 11 is provided between the robot arm 6 and the gripping portion 7 for moving the gripping portion 7 relative to the robot arm 6 in the XY direction.

[0005] The inner side surface 24a of the V-shaped guide 24 of the moving mechanism 11 abuts against the outer peripheral side surface 2a of the turntable 2 so as to sandwich the outer peripheral side surface 2a of the turntable 2. Thus, the centers of the grinder 3 and the turntable 2 coincide with each other, and the alignment of the grinder 3 in the XY directions is completed.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2002-103156 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In the conventional structure of Patent Document 1, since a large moving mechanism 11 is provided between the robot arm 6 and the gripping part 7, the overall structure of the robot becomes complicated. Since the moving mechanism 11 is provided, not only the weight that can be carried by the gripping part 7 is limited, but also the movable range of the robot arm 6 is limited. Therefore, the versatility of the robot is poor.

[0011] Therefore, in order to solve the above-mentioned problems, an object of the present disclosure is to provide a robot, a robot system, and a robot operation method that have a simple structure and excellent versatility compared to conventional structures.

[0012] Technical solutions to solve problems

[0013] In order to solve the above-mentioned problems, the present disclosure relates to a robot comprising: a robot hand mounted on a front end portion of a robot arm; and

[0014] a control unit, which controls the movements of the robot arm and the robot hand respectively to perform operations on the object,

[0015] The robot hand has a force sensor,

[0016] The control section controls the operation of the robot arm so that position information and posture information of the object are detected by the force sensor by pressing a part of the robot hand against the object.

[0017] According to the robot of the present disclosure, by detecting the position information and posture information of the object using the force sensor, it is possible to realize a robot having a simpler structure than the conventional structure and excellent versatility.

[0018] The present invention includes any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings. In particular, any combination of more than two of each claim in the claims is included in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be more clearly understood based on the description of the preferred embodiments with reference to the attached drawings. However, the embodiments and drawings are for illustration and description only and should not be used to limit the scope of the present invention. The scope of the present invention is determined by the attached claims. In the drawings, the same part numbers in multiple drawings represent the same parts.

[0020] Figure 1 is a perspective view of a robot system according to an embodiment of the present disclosure.

[0021] Figure 2 This is a perspective view of a robot hand used for carrying parts of the robot system.

[0022] Figure 3 It is a diagram for explaining a method of detecting the position of the working device of the robot system in the XY directions.

[0023] Figure 4 It is a top view partially showing the working device and the robot hand.

[0024] Figure 5A It is a partial enlarged view of components and the like showing a state in which the first gripper of the robot hand is pressed against a component mounted on the working device in the XY directions.

[0025] Figure 5B It is a partial enlarged view of a component and the like showing a state in which an engaging portion of a first jig is engaged with a first engaged portion of the component in the XY directions.

[0026] Figure 6 This is a diagram for explaining a method for detecting the Z-direction position and inclination of the working device.

[0027] Fig. 7A This is a cross-sectional view of the component and the like showing a state in which the second gripper of the robot hand is moved in the Z direction to the second engaged portion of the component.

[0028] Figure 7B It is a cross-sectional view of components and the like showing a state in which the engaging portion of the second clamp is engaged with the second engaged portion in the Z direction.

[0029] Figure 8 This is the front view of the robot hand.

[0030] Fig. 9 It is a bottom view showing the separation allowing portion of the component in an enlarged manner.

[0031] Fig.10 It is a bottom view of the robot hand etc. showing a state of detecting the reference position of the separation allowing portion.

[0032] Fig.11 This is a flow chart for detecting the reference position of the separation allowing portion.

[0033] Fig.12 This is a three-dimensional view of the robot hand used for bolt tightening and bolt loosening of the robot system.

[0034] Fig.13A This is a perspective view showing a state in which the tool of the robot hand is positioned at the center of the bolt hole.

[0035] Fig. 13B This is a perspective view showing a state in which the phase of the tool is matched with the bolt.

[0036] Fig.14 is a side view of the robot hand.

[0037] Fig.15A This is a diagram showing a state in which the rotating roller of the robot hand is brought into rolling contact with the bolt.

[0038] Fig. 15B This is a diagram showing a state where the bolt is detached from the component by rotating the roller.

[0039] Fig.16 It is a diagram showing a schematic structure of another modified example of the robot system. DETAILED DESCRIPTION

[0040] Hereinafter, an embodiment of the present disclosure will be described based on the drawings, but the present disclosure is not limited to the embodiment.

[0041] <Overall structure of the robot system>

[0042] Figure 1 The robot system 1 shown is a system that automatically replaces a component 3 as an object on a working device 4 by, for example, a control device 2. The robot system 1 includes a conveying platform 12, a component conveying robot 6, and a bolt tightening and loosening robot 7. The working device 4 includes a device body 4A, and the component 3 is detachably mounted on the device body 4A.

[0043] The component transport robot 6 includes a component transport robot hand 6a, and the bolt tightening and loosening robot 7 includes a bolt tightening and loosening robot hand 7a. The component transport robot hand 6a can hold the component 3 for transport, and can attach and detach the component 3 relative to the device body 4A. The bolt tightening and loosening robot hand 7a can move the bolt 8 ( Fig.12 ) Component 3 can be freely installed and removed relative to the device body 4A.

[0044] The control device 2 controls the entire robot system 1. The control device 2 includes a control unit 2a of the component transport robot 6, a control unit 2b of the bolt tightening and loosening robot 7, and a control unit 2c of the transport table 12. Hereinafter, the robot body of the component transport robot 6 excluding the control unit 2a is sometimes referred to as the robot 6, and the robot body of the bolt tightening and loosening robot 7 excluding the control unit 2b is sometimes referred to as the robot 7.

[0045] <Working equipment>

[0046] The working device 4 is fixed to an installation surface such as a floor, and the transfer platform 12 that supports the robots 6 and 7 moves relative to the fixed working device 4 . Figure 3 A three-dimensional orthogonal coordinate system is shown as a coordinate system defining a space in which the working device 4 is installed. The three-dimensional orthogonal coordinate system is defined by an X-axis and a Y-axis that are orthogonal to each other on a horizontal plane, and a Z-axis whose vertical direction is upward as a positive direction. The device body 4A can be driven to rotate around the Z-axis and is supported relative to a workpiece W ( Figure 1 ) are driven relatively in the Z direction.

[0047] A flange 9 for attaching and detaching the machining part 3 is provided at the lower end of the device body 4A in the Z direction. The flange 9 is in the shape of a circular plate coaxial with the Z axis and has a plurality of bolt insertion holes 9a on the outer periphery. The plurality of bolt insertion holes 9a are arranged at predetermined intervals along the circumferential direction, and each bolt insertion hole 9a is a through hole formed parallel to the Z axis. From the upper part of the flange 9 to each bolt insertion hole 9a, a plurality of bolt insertion holes 9a can be attached. Fig.13A The bolt 8 shown as the fastener. A hexagon socket head bolt is suitable as the bolt 8. The hexagon socket head bolt is sometimes simply referred to as a bolt.

[0048] <Parts>

[0049] Installed on Figure 3 The component 3 on the flange 9 is an annular component having an outer periphery having the same diameter as the outer periphery of the flange 9. The component 3 is provided with a plurality of bolt holes 3a ( Figure 4 ). Figure 4 Each bolt hole 3a of the component 3 shown is internally threaded. Fig. 7A As shown in FIG. 1 , an annular tapered portion 10 and an annular step portion 11 connected to the tapered portion 10 are provided on the inner periphery of the annular component 3. The tapered portion 10 is an annular portion provided on the lower surface of the component 3 and having a tapered shape with a diameter expanding from the upper end in the Z direction toward the lower end in the Z direction. The step portion 11 is connected to the lower end edge portion in the Z direction of the tapered portion 10 having the largest diameter.

[0050] <Robotic system>

[0051] like Figure 1 As shown, robots 6 and 7 are vertical multi-joint robots, and are supported on a conveying platform 12 with a predetermined step difference. Robot 7 is supported on the upper section of the conveying platform 12, and robot 6 is supported on the lower section of the conveying platform 12. The conveying platform 12 can, for example, carry out conveyance within a predetermined conveying path Rt range between the working device 4 and the component recovery platform 13. A component storage section 12a capable of storing components 3 and the like is provided on the conveying platform 12.

[0052] <Parts handling robot>

[0053] The robot 6 has a base 6b, a plurality of robot arms 6c having a plurality of joints, and a robot hand 6a for carrying parts. The base 6b is fixed to the lower stage of the conveying platform 12. On the conveying platform 12, a plurality of robot arms 6c are sequentially connected via the base 6b, and the robot hand 6a is installed at the front end of the robot arm 6c on the front end side. An angle detection sensor for detecting the rotation angle of the motor is provided on the motor provided at the above-mentioned joint.

[0054] Figure 2 The robot hand 6a shown in the figure includes a hand body 14, first and second clamps 15, 16, a component holding portion 17, a holding portion drive source 18, a rotation drive source 19, and sensors. The sensors include a force sensor 20 and a detection sensor 21. The hand body 14 in the form of a rectangular plate is mounted at the front end of the robot arm 6c. Figure 3 As shown, a first jig 15 is fixed to the longitudinal front end of the hand body 14. The first jig 15 detects the position of the device body 4A in the XY directions.

[0055] like Figure 4As shown, a first engaging portion 15a having a concave curved surface shape with a recessed central portion in the width direction is provided at the front end portion of the first fixture 15. The first engaging portion 15a engages with the first engaged portion 3b which is the outer peripheral portion of the component 3. The first engaged portion 3b is a portion of the outer peripheral surface (one side surface) of the component 3 within a specified circumferential direction range. The first engaging portion 15a is set to have the same curvature as the first engaged portion 3b and can abut against the first engaged portion 3b without a gap. The specified circumferential direction range is set, for example, by either or both of the test and the simulation.

[0056] like Figure 2 As shown, at the front end of the hand body 14 in the longitudinal direction, the second clamp 16 is rotatably supported via a rotation drive source 19. The second clamp 16 detects Figure 3 The position and inclination of the device body 4A in the Z direction. Figure 8 As shown, the second clamp 16 is in the shape of a plate parallel to the hand body 14. As the rotation drive source 19, for example, a motor is used, and the second clamp 16 rotates around the rotation axis C1 of the motor.

[0057] like Figure 2 As shown, the second clamp 16 has a second engaging portion 16a and a step portion 16b connected to the second engaging portion 16a at both ends of the second clamp 16 in the longitudinal direction. Fig. 7A The second engaging portion 16a and the second engaged portion 10 of the tapered portion 10 of the component 3 are engaged with each other. The second engaging portion 16a and the second engaged portion 10 are set to have the same slope. Figure 7B As shown, when the second engaging portion 16 a is engaged with the tapered portion 10 of the component 3 , the step portion 16 b of the second clamp 16 abuts against the step portion 11 of the component 3 .

[0058] exist Figure 2 A gripping portion drive source 18, a component gripping portion 17, and a detection sensor 21 are fixed to the second clamp 16. A pair of gripping portion drive sources 18, 18 for driving the component gripping portion 17 are fixed to both ends in the longitudinal direction of the second clamp 16. An air cylinder is used as each gripping portion drive source 18. The cylinder body of each air cylinder can move the rod 18a forward and backward in a radial direction A1 orthogonal to the rotation axis C1.

[0059] A circular holding member 3 ( Fig. 7A ) are provided with component holding portions 17, 17 on the outer peripheral surface. The component holding portions 17, 17 are provided with mutually opposing recessed portions 17a, 17a. Each component holding portion 17 is substantially V-shaped in plan view, with the center portion of the recessed portion 17a recessed radially outward. When each rod 18a protrudes, the component holding portions 17, 17 make the recessed portions 17a, 17a located at the component 3 ( Fig. 7A) radially outward of the outer peripheral surface, so that component 3 ( Fig. 7A When the rods 18a are retracted, the component holding portions 17, 17 hold the component 3 through the recessed portions 17a, 17a ( Fig. 7A )'s outer surface.

[0060] <About force sensors>

[0061] A force sensor 20 is fixed to a base end portion of the hand body 14 in the longitudinal direction. Figure 3 The force sensor 20 shown detects the position information and posture information of the component 3 mounted on the device body 4A. The force sensor 20 is a so-called 6-axis force sensor that can measure forces in the X, Y, and Z directions and torques around each axis of the X, Y, and Z axes. As the 6-axis force sensor, for example, a strain gauge force sensor is used. Fig.12 The force sensor 20A on the robot hand 7a is also the same 6-axis force sensor.

[0062] <Control device>

[0063] Figure 1 The control units 2a, 2b, and 2c of the control device 2 send and receive various signals such as the completion of the action to each other to synchronize the action timing of the robots 6, 7 and the conveying table 12. The control device 2 controls the robots 6, 7 and the conveying table 12, for example, according to the stored movement program. The device control unit Cu for controlling the working device 4 is, for example, a computer-type numerical control device, and controls the working device 4 according to the stored processing program. The device control unit Cu detects the wear of the component 3 as a consumable, or determines the replacement time of the component 3 based on the working time of the working device 4. When the device control unit Cu determines that it is time to replace the component 3, a replacement instruction for replacing the component 3 is output to the control device 2 on the robot system 1 side. When the replacement instruction from the device control unit Cu is input, the control device 2 causes the robots 6, 7 and the conveying table 12 to automatically perform the replacement operation of the component 3.

[0064] Control device 2 controls Figure 1 The action of the robot 6 is such that when the working device 4 approaches the robots 6 and 7, Figure 3 The control device 2 detects the position information and posture information of the component 3 mounted on the device body 4A by detecting the force sensor 20 shown. Whenever the working device 4 approaches and separates from the robots 6 and 7, the control device 2 detects the position information and posture information of the component 3 in the XYZ directions.

[0065] <About detection sensors, etc.>

[0066] like Figure 2As shown, a detection sensor 21 is installed at one end of the length direction of the second clamp 16. The detection sensor 21 can detect the Figure 3 The device body 4A of the component 3 Fig. 9 As the reference position Ps. Figure 8 The detection sensor 21 shown is, for example, a laser distance sensor. The laser distance sensor includes a laser irradiation unit 21a and a light receiving sensor unit 21b. The laser irradiation unit 21a irradiates a laser beam to a component located above the second fixture 16 in the Z direction. The light receiving sensor unit 21b receives reflected light of the laser beam. The detection sensor 21 utilizes the principle that the light receiving point of the reflected light is different according to the height of the detection unit of the component.

[0067] Fig.10 The control device 2 controls the action of the robot 6 so that when the working device 4 and the robot 6 are close to each other, the reference position Ps of the component 3 mounted on the device body 4A is detected by the detection sensor 21.

[0068] The control device 2 can displace the component 3 in the range between the support position Pa and the detached position Pb relative to the flange 9 through the robot hand 6a. The control device 2 drives the pair of gripping portion drive sources 18, 18 to grip the component 3 through the component gripping portions 17, 17, and drives the motor 19. Thus, the control device 2 can displace the component 3 from which the bolt is detached in the range between the support position Pa and the detached position Pb.

[0069] The support position Pa is a position where the component 3 is supported so that it does not fall off the flange 9 of the device body 4A after the bolt is detached. The detachment position Pb is a position where the component 3 is detached from the flange 9. On the inner peripheral surface of the component 3, a detachment allowing portion 22 is provided at the detachment position Pb to allow the component 3 to detach from the device body 4A. The detachment allowing portion 22 is Fig.10 The pair of cutouts 22, 22 shown in the figure are Fig. 7A A portion of the tapered portion 10 of the component 3 in the circumferential direction is cut into an arc shape. A pair of cutout portions 22, 22 are opposed to each other at positions equally divided by 180 degrees on the inner circumferential surface of the component 3.

[0070] A pair of fall prevention plates 23, 23 are supported on the flange 9 to prevent the component 3 from falling. A pair of fall prevention plates 23, 23 are supported on the outer peripheral end of the lower surface of the flange 9. Each fall prevention plate 23 is Fig.10 The bottom view of the flange 9 is in the shape of a circular plate. At the outer peripheral end of the flange 9, fall prevention plates 23, 23 are arranged at positions equally divided by 180 degrees with the rotation axis C1 of the motor 19 as the center. The position where the phases of the pair of cutouts 22, 22 of the component 3 and the fall prevention plates 23, 23 are aligned is the separation position Pb of the component 3.

[0071] At the disengagement position Pb, the outer edges of the pair of fall prevention plates 23, 23 and the arcs of the pair of cutouts 22, 22 are aligned. Fig.10 As a result, the component 3 can be detached from the device body 4A. The position of the component 3 where the phase of the pair of cutouts 22, 22 is offset by about 60 degrees relative to the fall prevention plates 23, 23 is the support position Pa. At the support position Pa, the circumferential portion of the component 3 that is offset by about 60 degrees from the position of the cutouts 22, 22 is supported on the fall prevention plates 23, 23.

[0072] like Fig. 9 As shown, a reference position Ps of the component 3 is provided on one or both of the cutout portions 22 . Fig.10 The control device 2 shown calculates as Fig. 9 The illustrated point is an intermediate point between the first and second step differences P1 and P2 at the intersection of the trajectory L of the laser irradiation point and the notch 22 . Fig.10 The control device 2 calculates as by Fig. 9 The reference angle between the center of the component 3 and the middle point is the reference position Ps. The positions of the bolt holes of the component 3 are obtained based on the reference position Ps. Figure 1 The control device 2 detects each time when the working device 4 and the robots 6 and 7 approach and separate. Fig. 9 The reference position Ps of the cutout portion 22 is as follows.

[0073] <Robots for bolt tightening and loosening>

[0074] like Figure 1 As shown, the robot 7 has a base 7b, a plurality of robot arms 7c having a plurality of joints, and a robot hand 7a for bolt tightening and bolt loosening. The base 7b is fixed to the upper section of the conveying platform 12. On the conveying platform 12, a plurality of robot arms 7c are sequentially connected via the base 7b, and the robot hand 7a is mounted on the front end of the robot arm 7c on the front end side. An angle detection sensor for detecting the rotation angle of the motor is provided in the motor provided in the above-mentioned joint.

[0075] Fig.12 The robot hand 7a shown includes a hand frame 24, a tool 25, a roller drive system 26, a bolt holding device 27 and sensors. The sensors include a force sensor 20A and Fig.14 The height detection unit 30 is shown. Fig.12 A rectangular plate-shaped hand frame 24 is mounted on the front end portion of the robot arm 7c.

[0076] <About tightening and loosening bolts with a hexagon bit>

[0077] A hexagonal screwdriver bit as a tool 25 is fixed to the front end in the longitudinal direction of the hand frame 24. The hexagonal screwdriver bit 25 is inserted into the hexagonal hole of the head 8a of the hexagon socket head bolt 8 to attach and detach the bolt 8. A force sensor 20A is fixed to the base end in the longitudinal direction of the hand frame 24. The force sensor 20A is used to attach and detach the bolt 8.

[0078] <About tightening and loosening of bolts in the roller drive system>

[0079] The roller drive system 26 includes a rotating roller 28 and a drive device 29 that applies a rotational driving force to the rotating roller 28. Two rotating rollers 28, 28 are rotatably supported at the front end in the longitudinal direction of the hand frame 24. The rotating rollers 28, 28 are supported around an axis parallel to the thickness direction of the hand frame 24 at a predetermined interval.

[0080] like Fig.14 As shown, each rotating roller 28 has a rotating shaft 28a supported on the hand frame 24 and an annular elastic member 28b coaxially provided at the front end of the rotating shaft 28a. Rubber or the like is used as the elastic member 28b. The rotating rollers 28, 28 make each elastic member 28b roll against both side surfaces of the head 8a which is a part of the bolt 8, so as to pre-tighten or pre-loosen the bolt 8.

[0081] The driving device 29 includes a motor 31 supported by the hand frame 24 and a gear train 32 for transmitting the rotational force of the motor 31 to the rotating rollers 28, 28. The gear train 32 reduces the rotational force of the motor 31 and transmits it to the rotating rollers 28, 28.

[0082] Fig.12 The force sensor 20A is a pressing force detection unit that detects the pressing force of the rotating roller 28 relative to the bolt 8. Figure 1 As shown, when the working device 4 approaches the robots 6 and 7, the control device 2 Fig.12 The robot hand 7a is positioned by the pressing force detected by the pressing force detection unit 20A. When the pressing force of the rotating roller 28 acts on the head 8a of the bolt 8, the force sensor 20A detects the reaction force of the above pressing force.

[0083] exist Fig.14 A height detection unit 30 for detecting the height of the bolt 8 relative to the component is installed at the front end portion of the hand frame 24 in the longitudinal direction. A proximity sensor is used as the height detection unit 30. Fig.15A As shown, the detection portion of the proximity sensor 30 faces the elastic member 28 b with a predetermined gap therebetween, for example.

[0084] exist Fig.12 The front end of the hand frame 24 in the longitudinal direction supports a bolt holding device 27 for holding the contracted portion of the bolt 8. The bolt holding device 27 includes a chuck 27a for holding the bolt 8 and a Fig.14 The driving source 27b of the chuck 27a shown in the figure. The chuck 27a holds the contracted portion of the bolt 8 in an openable and closable manner from both the left and right sides. As the driving source 27b, an air cylinder for opening and closing the chuck 27a is used.

[0085] The control device 2 controls the driving source 27b so that when the bolt 8 is loosened, when the bolt 8 is lifted and the head 8a of the bolt 8 is detected by the proximity sensor 30, the chuck 27a holds the contracted portion of the bolt 8. Then, the control device 2 drives the robot hand 7a so that the bolt 8 is removed from the component while being held by the chuck 27a. The removed bolt 8 is temporarily supported, for example, by Figure 1 The supporting platform of the working device 4 can be reused when replacing the component 3. The reverse order of the bolt loosening can be used. Fig.14 The roller drive system 29 pre-tightens the bolts 8 .

[0086] [Robot system actions and effects]

[0087] like Figure 1 As shown, when a replacement command is input from the device control unit Cu, the control device 2 moves the robots 6 and 7 storing the replacement component 3 on the transfer platform 12 to a position close to the working device 4 and detects the position and inclination of the working device 4.

[0088] <Position detection method of the working device in the XY direction>

[0089] like Figure 4 As shown, the control device 2 moves the robot arm 6 c in the horizontal direction, that is, the XY direction, so as to press the first clamp 15 fixed to the robot hand 6 a against the outer peripheral surface of the component 3 .

[0090] like Figure 5A As shown, when the edge portion 15aa of one side of the first engaging portion 15a contacts the outer peripheral surface of the component 3, a moment about the Z axis acts on the component 3. At this time, Figure 3 The force sensor 20 detects the reaction force of the above torque.

[0091] The control device 2 moves the robot arm 6c in the XY direction in a direction that reduces the above-mentioned reaction force as the sensor output of the force sensor 20, and Figure 5B As shown, the first engaging portion 15a of the first clamp 15 is engaged with the first engaged portion 3b of the component 3. When the first engaging portion 15a is engaged with the first engaged portion 3b, the reaction force of the moment is zero.

[0092] Figure 1 When the reaction force is zero, the control device 2 obtains the rotation angles of the motors provided on the joints of the robot arms 6c from the angle detection sensors to detect the rotation angles of the motors provided on the joints of the robot arms 6c. Figure 4 The device center P4. The above-mentioned "each rotation angle" is the relative angle of each motor of the joint from the reference angle. The reference angle of each motor is synonymous with the origin of each motor in the prescribed reference posture of the robot arm 6c. Figure 6 The method for detecting the Z-direction position and inclination of the working device 4 is also the same. Figure 4 The device center P4 shown is installed in Figure 3 The temporary center in the XY direction of the component 3 on the device body 4A.

[0093] <Method for detecting the Z-direction position and inclination of the working device>

[0094] After the device center P4 is detected, the Z-direction position and inclination of the working device 4 are detected. Figure 6 As shown, the control device 2 moves the robot arm 6a so that the second fixture 16 is located below the component 3 in the Z direction, and the rotation axis C1 of the second fixture 16 is consistent with the device center P4. Fig. 7A As shown, the control device 2 makes Figure 2 The robot arm 6 c moves upward in the Z direction so that the second engaging portion 16 a is pressed against the second engaged portion 10 .

[0095] When a portion of the second joint portion 16a is Fig. 7A When the second engaged portion 10 of the component 3 shown in the figure abuts, a moment about the Y axis acts on the component 3. At this time, Figure 6 The force sensor 20 detects the reaction force of the above torque.

[0096] The control device 2 moves the robot arm 6a in a direction to reduce the above-mentioned reaction force as the sensor output of the force sensor 20, and Figure 7B The second engaging portion 16a of the second clamp 16 engages with the second engaged portion 10 of the component 3. At this time, the step portion 16b of the second clamp 16 abuts against the step portion 11 of the component 3. When the second engaging portion 16a engages with the second engaged portion 10, the reaction force of the moment is zero.

[0097] Figure 1 When the reaction force is zero, the control device 2 obtains the rotation angles of the motors provided on the joints of the robot arms 6c from the angle detection sensors to detect the rotation angles of the motors provided on the joints of the robot arms 6c. Figure 6 The Z direction position, inclination and final position in the XY direction of the working device 4 are respectively the Z direction position information, posture information and final center position information in the XY direction of the component 3 installed on the device body 4A. Figure 7BAs shown, when the second engaging portion 16 a is engaged with the second engaged portion 10 , the center of the component 3 in the XY direction can be found with high accuracy by correcting the temporary center of the component 3 in the XY direction.

[0098] Figure 6 The control device 2 is based on the sensor output of the force sensor 20, such as Figure 7B As shown, by engaging the second engaging portion 16a with the second engaged portion 10 of the component 3, the position information and posture information of the component 3 in the XYZ direction can be simply and reliably detected. Figure 1 When the working device 4 and the robots 6 and 7 are close to each other, the control device 2 corrects the deviation of the relative position and inclination between the working device 4 and the robots 6 and 7 according to the position information and posture information of the component 3. Figure 2 The force sensor 20 detects the position information and posture information of the component 3, so compared with the existing structure with the above-mentioned large moving mechanism, the number of components can be reduced to simplify the structure, and the transportable weight and movable range can be increased. Therefore, compared with the existing structure, it is possible to improve Figure 1 The versatility of the robot system 1 as a whole. For example, using Figure 6 The force sensor 20 shown detects the position information and posture information of the component 3 without relying on a camera or the like. Therefore, even if the gap below the component 3 mounted on the working device 4 cannot be ensured to be the distance required for imaging, it is possible to reliably correct the position information. Figure 1 The deviation of the relative position and inclination of the working device 4 and the robots 6 and 7.

[0099] When the working device 4 and the robots 6 and 7 are allowed to move relative to each other so as to approach and separate, deviations may occur in the relative positions and inclinations of the working device 4 and the robots 6 and 7. In this structure, when the working device 4 and the robots 6 and 7 approach each other, the deviations in the relative positions and inclinations of the working device 4 and the robots 6 and 7 are corrected as described above.

[0100] <Method for detecting the reference position of the cutout>

[0101] Fig.11 This is a flow chart for detecting the reference position of a component.

[0102] like Fig.10 As shown in FIG. 2 , when the working device 4 and the robot 6 are close to each other and the component 3 is mounted on the flange 9, the process of detecting the reference position Ps is started. Fig.10 The robot arm 6c moves so that Figure 8 The second fixture 16 is located below the component 3 in the Z direction, and the rotation axis C1 of the second fixture 16 is aligned with the center P4 of the device ( Figure 4 ) Fig.11:Step S1).

[0103] Next, the control device 2 drives the motor 19 to rotate a predetermined angle. At the same time, the control device 2 irradiates the component 3 with laser light ( Fig.11 :Step S2). Fig. 9 The trajectory L of the laser irradiation point shown is aligned with the bolt hole 3a ( Figure 5B ) is concentric and passes through the radial middle portion of the cutout portion 22. The above pitch circle is Figure 5B The circle PC of the centers of the plurality of bolt holes 3a of the component 3 is shown.

[0104] Fig.10 When the control device 2 detects a rise in the sensor input signal by the detection sensor 21, the rise is regarded as Fig. 9 The first order difference P1 of the detection location is recorded Fig.10 The first current position of the motor 19 shown, i.e. the rotation angle ( Fig.11 :Steps S3, S4). When the control device 2 detects a decrease in the sensor input signal through the detection sensor 21, the control device 2 regards the decrease as the second step difference P2 ( Fig. 9 ), and record the second current position of the motor 19 at the detection location, that is, the rotation angle ( Fig.11 :Steps S5, S6). The control device 2 calculates the recorded Fig. 9 The middle point between the first current position P1 and the second current position P2 ( Fig.11 :Step S7). Consider the above-mentioned intermediate location as Fig.10 The control device 2 is thus able to calculate the reference angle Ps, which is the reference position passing through the center of the component 3 and the intermediate point. Then, the control device 2 stops the driving of the motor 19, and ends the present process ( Fig.11 :Step S8).

[0105] <How to loosen a hexagonal screwdriver head>

[0106] The control device 2 holds the component 3 using the component holding portions 17, 17 of the robot hand 6a, and Fig.13A As shown, the hexagonal screwdriver bit 25 is inserted into the hexagonal hole 8b for positioning. Fig.12 The control device 2 moves the robot arm 7c to Fig.12 The rotation center of the hexagonal screwdriver bit 25 is positioned according to Fig.10 The bolt hole 3a of the component 3 is calculated from the reference position Ps of the component 3 ( Figure 5B ) center. Specifically, Figure 5B The bolt hole 3a of the component 3 shown is screwed Fig.13AThe center of the hexagonal hole 8b of the hexagonal socket head bolt 8 is aligned with the rotation center C2 of the hexagonal bit 25.

[0107] Fig.12 The control device 2 is based on the sensor output of the force sensor 20A, such as Fig.13A As shown, the hexagonal screwdriver bit 25 is moved downward in the Z direction, and Fig.12 That is, the control device 2 rotates the robot hand 7a around the rotation center of the hexagonal screwdriver bit 25 so that the hexagonal screwdriver bit 25 is aligned in phase while applying the pressing force of the hexagonal screwdriver bit 25 to the head 8a of the hexagon socket head bolt 8. When the downward pressing force of the hexagonal screwdriver bit 25 in the Z direction acts on the head 8a of the hexagon socket head bolt 8, the force sensor 20A detects the reaction force of the above-mentioned pressing force.

[0108] The control device 2 monitors the above reaction force and searches for Fig.13A The hexagonal hole 8b of the hexagon socket head bolt 8 shown is in phase with the hexagonal screwdriver bit 25. Fig.13A In the embodiment, the hexagonal screwdriver bit 25 is located at a phase where the hexagon socket head screw 8 cannot be installed or removed relative to the object. Fig. 13B As shown, Fig.12 The control device 2 uses the fact that the reaction force of the pressing force does not work when the phases of the hexagonal hole 8b and the hexagonal screwdriver bit 25 are aligned, and finds the position where the phases are aligned. Fig. 13B The hexagonal bit 25 is displaced to a phase where it can be attached or detached from the hexagonal socket head bolt 8 as a component.

[0109] Fig.12 The control device 2 drives the robot hand 7a in a state where the phase of the hexagonal screwdriver 25 is aligned with the hexagonal hole of the hexagon socket bolt 8. By repeatedly aligning the phase of the hexagonal screwdriver 25 and driving the robot hand 7a, the bolt of the hexagonal screwdriver 25 is loosened. The control device 2 can tighten the bolt 8 using the robot hand 7a in the reverse order of the bolt loosening.

[0110] As described above, while the pressing force of the hexagonal screwdriver bit 25 is applied to the bolt 8 supported by the component, the hexagonal screwdriver bit 25 is displaced from a phase in which the bolt 8 cannot be attached to or detached from the component to a phase in which it can be attached to or detached from the component according to the sensor output of the force sensor 20A. Therefore, the hexagonal screwdriver bit 25 is repeatedly driven without interfering with a part of the component, so that the bolt 8 can be loosened or tightened. Therefore, compared with the existing structure using a drive unit, etc., the object as the working object is not limited, and it can become a robot with excellent versatility.

[0111] <How to loosen bolts in the roller drive system>

[0112] After the bolt of the hexagonal screwdriver 25 is loosened, the control device 2 is used Figure 2 The component holding portion 17, 17 holds the component, while Fig.14 The rotating rollers 28, 28 are pressed against the bolt 8, and the Fig.12 The force sensor 20A detects the reaction force of the pressing force. The control device 2 presses the rotating rollers 28, 28 against the side of the head 8a of the bolt 8 so that the pressing force that can be used to tighten and loosen the bolt can be obtained while monitoring the reaction force. The pressing force that can be used to tighten and loosen the bolt can be set in advance through simulation or experiment. After the desired pressing force is reached, the control device 2 Fig.15A As shown, control Fig.14 A driving device 29 is provided to apply a rotational driving force to the rotating roller 28.

[0113] In the roller drive system 26, Fig. 15B When the bolt 8 is loosened as shown, the bolt 8 approaches the hand frame 24 with the head 8a of the bolt 8 ( Fig.14 Therefore, by using the proximity sensor 30 to detect whether the head 8a of the bolt 8 exists, the so-called idling of the rotating roller 28 can be prevented.

[0114] Fig.14 When the bolt 8 is loosened, the control device 2 controls the driving source 27 b to make the chuck 27 a hold the contracted portion of the bolt 8 when the bolt 8 is lifted and the presence of the head 8 a of the bolt 8 is detected by the proximity sensor 30 .

[0115] Next, the control device 2 drives the robot hand 7a so that the robot hand 7a moves from the state where the bolt 8 is held by the chuck 27a. Figure 1 The component 3 shown is removed. Fig.14 The bolt 8 is temporarily supported on a specified support platform before replacing the component 3 ( Figure 1 The roller drive system 26 can pre-tighten the bolts 8 in the reverse order of loosening the bolts.

[0116] Remove bolt 8 from Figure 1 After the component 3 is removed, the control device 2 is driven while the component holding portions 17, 17 hold the component 3. Fig.10 The motor 19 moves the component 3 to the disengaged position Pb. The control device 2 drives the robot hand 6a to store the component 3 in the Figure 1 Next, the control device 2 drives the robot hand 6a so that the replacement component 3 is grasped by the component grasping parts 17, 17 and displaced relative to the device body 4A to the position where the replacement component 3 is located. Fig.10 The supporting position Pa.

[0117] Control device 2 passes and passes Fig.12The roller drive system 26 loosens the bolts in the reverse order to pre-tighten the bolts 8. Figure 1 The component holding portion 17, 17 holds the component 3 while using Fig.12 The hexagonal screwdriver 25 tightens the bolt 8 in the reverse order of the loosening of the bolt. When tightening the bolt, the force sensor 20A is used to manage the tightening torque. Based on the sensor output of the force sensor 20A, the control device 2 drives the robot hand 7a to swing in a specified direction so that the hexagon socket head bolt 8 is tightened with a specified tightening torque. The specified tightening torque is met by repeatedly aligning the phase of the hexagonal screwdriver 25 and driving the robot hand 7a. For example, by using a setting Figure 1 The torque correction device 33 on the component recovery station 13 or the like periodically corrects the tightening torque of the force sensor 20A.

[0118] Then, the control device 2 moves the transfer stage 12 to the component collection stage 13 and drives the robot 6 so that the component gripping parts 17 , 17 grip the used component 3 and support it at a predetermined position.

[0119] <Modification>

[0120] The predetermined operation of the working device 4 is not limited to machining, and examples thereof include application of paint, adhesive, grease, etc. to a workpiece, welding, photography, inspection, measurement, and assembly, and other various operations.

[0121] Various operations such as machining can be performed by manually operating the operation device 4, and various manual operations and various automatic operations using the device control unit Cu as a control body can be used in combination.

[0122] exist Figure 2 In the embodiment, the second clamp 16 is directly connected to the output shaft of the motor 19 , but the second clamp 16 may be connected to the output shaft of the motor 19 via a rotational driving force transmission mechanism such as a belt.

[0123] Figure 2 , Fig.12 If the force sensor 20, 20A is a 6-axis force sensor, a sensor other than a strain gauge type such as an electrostatic capacitance type, a piezoelectric type, or an optical type may be used. The force sensor 20, 20A may perform torque calibration irregularly or at regular intervals.

[0124] Can also replace Figure 1 The working device 4 can be moved by the movement of the robots 6, 7, etc. The working device 4 and the robots 6, 7, etc. can also be moved independently.

[0125] The robot 6 or the robot 7 may be used independently. For example, the robot 6 may be supported on the conveying platform 12 for conveying, or the robot 6 may be fixed on a mounting surface such as a floor. Similarly to the above, the robot 7 may be supported on the conveying platform 12 for conveying, or the robot 7 may be fixed on a mounting surface such as a floor.

[0126] Fasteners are not limited to Fig.13A As the hexagon socket head bolt 8, for example, a TORX (registered trademark) screw, a hexagonal bolt, a small screw, etc. can be applied.

[0127] As Figure 2 The detection sensor 21 may be an ultrasonic sensor or the like other than a laser distance sensor.

[0128] exist Fig.12 In the roller driving system 26, only one of the two rotating rollers 28 and 28 may be driven to rotate, and the other rotating roller 28 is driven to rotate by the friction force with the bolt 8. In this case, compared with the above-mentioned embodiment, the number of gears in the gear train can be reduced, and the structure can be simplified.

[0129] Figure 1 The device body 4A can also be an operating device that is driven to rotate around a horizontal axis.

[0130] like Fig.16 As shown, the first engaging portion 15a of the first clamp 15 may also be a V-shaped in a plan view so as to engage with the first engaged portion 3b as the outer peripheral portion of the component 3. In this case, compared with an embodiment in which the first engaging portion 15a is set to have the same curvature as the first engaged portion 3b, the structure of the first clamp 15 can be simplified, thereby achieving cost reduction.

[0131] As a method for detecting the position information and posture information in the XYZ direction, it is also possible to detect the position information and posture information at predetermined intervals or at intervals. Figure 1 After the approach and separation of the working device 4 and the robots 6 and 7 are repeated a predetermined number of times, the position information and posture information in the XYZ directions are detected.

[0132] According to the mounting structure of the component 3 relative to the working device 4, it is also possible to Fig. 7A The upper surface of the component 3 is provided with a second engaged portion 10, so that Figure 3 The robot arm 6 c moves downward in the Z direction to press the second engaging portion 16 a against the second engaged portion 10 .

[0133] The member 3 is not limited to an annular member, and may be, for example, a polygonal shape.

[0134] Fig.12 The gear train 32 may be a mechanism for increasing the speed of the rotational force of the motor 31 .

[0135] As described above, the robot 6 of the first mode of the present embodiment includes: a robot hand 6a attached to the front end of a robot arm 6c; and a control unit 2a that controls the operation of the robot arm 6c and the robot hand 6a to work on the object 3, the robot hand 6a has a force sensor 20, and the control unit 2a controls the operation of the robot arm 6c so that the position information and posture information of the object 3 are detected by the force sensor 20 by pressing a part of the robot hand 6a against the object 3. According to this structure, since the position information and posture information of the object 3 are detected by the force sensor 20, the number of parts of the robot 6 can be reduced and the structure can be simplified compared with the conventional structure having the above-mentioned large moving mechanism, and the loadable weight and movable range can be increased. Therefore, the versatility of the robot 6 can be improved compared with the conventional structure. The position information and posture information of the component 3 mounted on the device body 4A are detected by the force sensor 20 without using a camera or the like. Therefore, even when a clearance below the component 3 mounted on the working device 4 cannot be ensured, deviations in the relative positions and inclinations between the working device 4 and the robots 6 and 7 can be reliably corrected.

[0136] The robot 6 of the second mode of the present embodiment may be such that, in the first mode, the control unit 2a moves the robot arm 6c in the horizontal direction in a direction in which the sensor output of the force sensor 20 decreases, while the first engaging portion 15a as a part of the robot hand 6a is pressed against the first engaged portion 3b on one side surface of the object 3. According to this structure, the horizontal position information of the object 3 can be simply and reliably detected by pressing a part of the robot hand 6a against one side surface of the object 3. Since the position information of the object 3 can be detected without newly adding a large mechanism, the number of components can be reduced and the structure can be simplified compared to the above-mentioned conventional structure, and the handling weight and movable range can be reliably increased.

[0137] The robot 6 of the third aspect of the present embodiment may be such that, in the second aspect, the control unit 2a moves the robot arm 6c in the vertical direction in a direction in which the sensor output of the force sensor 20 decreases, while the second engaging portion 16a as a part of the robot hand 6a is pressed against the second engaged portion 10 provided on the lower surface or the upper surface of the object 3, thereby detecting the vertical position information and posture information of the object 3. According to this structure, by pressing a part of the robot hand 6a against the second engaged portion 10 of the object 3, the position information and posture information of the object 3 can be detected. Therefore, compared with the above-mentioned conventional structure, the number of components can be reduced and the structure can be simplified, and the handling weight and movable range can be reliably increased.

[0138] The robot system 1 of the fourth aspect of the present embodiment includes the robot 6 of any one of the first to third aspects and a working robot 7 that performs a predetermined operation on the object 3. With this configuration, the detection of the position information and posture information of the object 3 and the operation on the object 3 can be performed in cooperation.

[0139] The operation method of the robot 6 of the fifth mode of the present embodiment is to press a part of the robot hand 6a against the object 3, and move the robot arm 6c connected to the base end of the robot hand 6a in a direction in which the sensor output of the force sensor 20 provided on the robot hand 6a decreases, thereby detecting the position information of the object 3. According to this structure, the position information and posture information of the object 3 are detected by the force sensor 20. Therefore, compared with the existing structure having the above-mentioned large moving mechanism, the number of parts of the robot 6 can be reduced to simplify the structure, and the carrying weight and movable range can be increased. Therefore, compared with the existing structure, the versatility of the robot 6 can be improved.

[0140] As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, changes, or deletions may be made without departing from the gist of the present invention. Therefore, such cases are also included in the scope of the present invention.

[0141] Description of Reference Numerals

[0142] 1Robotic system

[0143] 2 Control device

[0144] 2a Control unit

[0145] 3 parts (objects)

[0146] 3b: first engaged portion

[0147] 6. Robots

[0148] 6a Robotic Hand

[0149] 6c Robot Arm

[0150] 10 tapered portion (second engaged portion)

[0151] 15a First engaging portion

[0152] 16a Second engaging portion

[0153] 20, 20A force sensor

Claims

1. A robot, characterized in that: have: a robot hand mounted on the front end of the robot arm; and a control unit, which controls the movements of the robot arm and the robot hand respectively to perform operations on the object, The robot hand has a force sensor, The control section controls the operation of the robot arm so that position information and posture information of the object are detected by the force sensor by pressing a part of the robot hand against the object.

2. The robot according to claim 1, characterized in that: When a first engaging portion as a part of the robot hand is pressed against a first engaged portion on a side surface of the object, the control unit detects horizontal position information of the object by moving the robot arm in the horizontal direction in a direction in which the sensor output of the force sensor decreases.

3. The robot according to claim 2, characterized in that: When the second engaging portion as a part of the robot hand is pressed against the second engaged portion arranged on the lower surface or the upper surface of the object, the control unit detects the vertical position information and posture information of the object by moving the robot arm in the vertical direction in the direction in which the sensor output of the force sensor is reduced.

4. A robot system, characterized in that: A robot according to claim 1 and a working robot that performs a predetermined operation on the object.

5. A robot operation method, characterized in that: The position information of the object is detected by pressing a part of the robot hand against the object and moving a robot arm connected to the base end of the robot hand in a direction in which the sensor output of the force sensor provided on the robot hand decreases.

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