JP6638384B2 - Robot hand and cable handling method - Google Patents

Description

  The present application relates to a robot hand and a cable steering method.

  In recent years, various types of robots have been used in factories (for example, see Patent Document 1).

JP-A-2-53588

  2. Description of the Related Art Various cables for electrically connecting components are used in electronic devices. The cable is routed according to a predetermined wiring route so as not to interfere with the operation of assembling the electronic device. Therefore, when a cable routing operation is automated, it is desired that the robot responsible for the operation has the ability to grasp and position the cable and the ability to route the grasped cable according to a predetermined wiring route without releasing the cable. However, a robot hand capable of both positioning and routing the cable has not been realized.

  Thus, the present application discloses a robot hand and a cable handling method capable of positioning and routing a cable.

  This application discloses the following robot hand. That is, the robot hand disclosed in the present application is a hand having a finger that can hang a cable to be grasped, a press that can press the cable laid on the finger against the finger, and the strength of the force that the press presses the cable. Control means adjustable to a first strength used when the cable is gripped by the hand, and a second strength weaker than the first strength used when the cable is pulled by the hand while sliding on the finger. , Is provided.

  Further, the present application discloses the following cable steering method. That is, the cable steering method disclosed in the present application, a cable is placed on a finger of a hand capable of hanging a cable to be grasped, the cable held on the finger is pressed against the finger by pressing, and the strength of the force that the pressing presses on the cable, The first strength used when the hand grips the cable and the second strength lower than the first strength used when the cable is pulled by the hand while sliding on the finger are adjusted.

  With the robot hand and the cable pulling method described above, positioning and routing of the cable can be performed.

FIG. 1 is a diagram illustrating an example of a robot. FIG. 2 is a perspective view of the robot hand. FIG. 3 is a structural diagram of the retainer. FIG. 4 is an enlarged view of the bush. FIG. 5 is a diagram showing a control system for controlling the robot hand. FIG. 6 is a diagram showing a flowchart of the operation realized by the robot. FIG. 7 is a diagram illustrating a state where the robot hand approaches the cable. FIG. 8 is a diagram showing a state in which a finger is closed. FIG. 9 is a diagram illustrating a state where the cable is gripped by the robot hand. FIG. 10 is a graph showing a change in the flow rate of the control air flowing through the hollow portion of the presser. FIG. 11 is a diagram showing a state of positioning of the cable. FIG. 12 is a diagram showing how the cable is routed. FIG. 13 is a diagram illustrating an operation state of the robot hand according to the comparative example. FIG. 14 is a diagram showing a positional relationship between the diameter of the cable and the elastic body. FIG. 15 is a diagram showing the relationship between the diameter of the cable and the pressed state of the bush. FIG. 16 is a diagram showing a modification of the bush. FIG. 17 is a diagram showing a contact state between a bush and a cable according to a modification. FIG. 18 is a diagram illustrating a robot hand provided with hook-shaped fingers instead of two fingers.

  Hereinafter, embodiments will be described. The embodiments described below are merely examples, and do not limit the technical scope of the present disclosure to the following aspects.

  FIG. 1 is a diagram illustrating an example of a robot. The robot 1 is a so-called articulated robot, and includes a robot arm 2 and a robot hand 3 provided at a tip of the robot arm 2. The robot arm 2 includes a first arm 1A1 connected to the base 1B via the first joint 1K1, and a second arm 1A2 connected to the distal end of the first arm 1A1 via the second joint 1K2. The robot hand 3 is provided at the tip of the second arm 1A2 via the third joint 1K3.

  FIG. 2 is a perspective view of the robot hand 3. The robot hand 3 has two fingers 4,4. The two fingers 4, 4 can be moved by an actuator 5 that opens and closes between the fingers 4, 4. The two fingers 4, 4 are provided at their tips with claws 6, 6, which are slightly inclined. The claws 6, 6 of each finger 4, 4 face each other. Therefore, when the space between the two fingers 4 and 4 is closed by the actuator 5, the claws 6 and 6 come into contact with each other. When the two fingers 4 and 4 are closed by the actuator 5 and the claws 6 and 6 come into contact with each other, an enclosure surrounding the cable to be grasped by the robot hand 3 is formed between the two fingers 4 and 4. . In addition, the inside of the claws 6 and 6 is subjected to Teflon treatment ("Teflon" is a registered trademark) so that the cable slides when the robot 1 draws the cable. The insides of the claws 6 and 6 only need to have a coefficient of friction that allows them to slide when the cable is routed. For example, various low-friction treatments or members other than Teflon treatment may be applied.

  Further, the robot hand 3 has a presser 7 for pressing the cable enclosed between the two fingers 4, 4 against the fingers 4, 4. The presser 7 has a hollow cylindrical member 8 and a rubber bush 9 fitted to the open end of the cylindrical member 8.

FIG. 3 is a structural diagram of the retainer 7. The cylindrical member 8 has a hollow portion 10. The cylindrical member 8 is provided with an inflow hole 11 communicating with the hollow portion 10. In the cylindrical member 8, a tube through which the control air for moving the bush 9 flows and the hollow portion 10 are connected via the inflow hole 11. When the control air flows from the inflow hole 11, the pressure in the hollow portion 10 increases, and the rubber bush 9 fitted to the open end of the cylindrical member 8 expands outward. The rubber forming the bush 9 is an example of the “elastic body” referred to in the present application, and various materials other than the elastically deformable rubber can be applied as the elastic body.

  FIG. 4 is an enlarged view of the bush 9. A fine through-hole 12 is formed at the center of the bush 9. Therefore, when the control air flows into the hollow portion 10 of the cylindrical member 8, air leaks from the through-hole 12 from the time when the bush 9 starts to expand to the time when the bush 9 contacts the cable and the through-hole 12 is closed by the cable. Will continue.

  FIG. 5 is a diagram illustrating a control system that controls the robot hand 3. The control system 13 for controlling the robot hand 3 includes a system control unit 18, an actuator control unit 14, a flow / pressure controller 15, and a flow sensor 16. The system control unit 18 is a control device that controls the robot hand 3. When receiving a command from the robot controller 17 that controls the robot 1, the system control unit 18 issues various commands to the flow / pressure controller 15 and the actuator control unit 14. The flow / pressure controller 15 is a controller for a valve provided in the middle of the air path from the compressed air supply path to the presser 7, and opens and closes the valve at an opening according to a command from the system control unit 18. I do. The flow rate sensor 16 is a sensor that detects the flow rate of control air provided in the air path from the flow rate / pressure controller 15 to the presser 7, and a signal line is connected to the system control unit 18. The actuator control unit 14 is a control circuit that controls the actuator 5 that opens and closes the fingers 4 and 4 of the robot hand 3, and opens and closes the fingers 4 and 4 according to a command from the system control unit 18.

  FIG. 6 is a diagram showing a flowchart of the operation realized by the robot 1. For example, in the assembly line of an electronic device, in a case where the robot 1 performs an operation of attaching a cable to be routed inside the electronic device, the robot 1 realizes the following operation.

  That is, the robot controller 17 issues a command to open the robot hand 3 to the system control unit 18 and moves the robot arm 2 to bring the robot hand 3 closer to the cable (S101). FIG. 7 is a diagram showing how the robot hand 3 approaches the cable. When the robot controller 17 issues a command to open the robot hand 3 to the system control unit 18, the space between the fingers 4 and 4 of the robot hand 3 opens. Therefore, when the robot hand 3 with the fingers 4, 4 being opened is moved by the robot arm 2 to approach the cable 19, the cable 19 can be inserted between the fingers 4, 4.

  After the cable 19 enters between the fingers 4 and 4, the robot controller 17 issues a command to the system control unit 18 to close the robot hand 3 (S102). FIG. 8 is a diagram showing a state where the fingers 4 and 4 are closed. After the cable 19 enters between the fingers 4, 4, when the robot controller 17 issues a command to close the robot hand 3 to the system control unit 18, the actuator control unit 14 moves the actuator 5 to move the finger of the robot hand 3. Close between 4 and 4. When the fingers 4, 4 close and the claws 6, 6 come into contact with each other, the robot hand 3 holds the cable 19 between the fingers 4, 4.

  After closing the fingers 4, 4, the robot controller 17 instructs the system controller 18 to hold the cable 19 (S 103). FIG. 9 is a diagram illustrating a state in which the cable 19 is gripped by the robot hand 3. After closing the fingers 4, 4, when the robot controller 17 instructs the system control unit 18 to hold the cable 19, the flow / pressure controller 15 sends control air to the presser 7. When the control air flows into the hollow portion 10 of the presser 7, the bush 9 starts to expand outward.

After the supply of the control air to the presser 7 is started, the system controller 18 monitors the output of the flow sensor 16 (S104). FIG. 10 is a graph showing a change in the flow rate of the control air flowing through the hollow portion 10 of the presser 7. Since the bush 9 is provided with the through-hole 12, the control air continues to flow into the hollow portion 10 of the presser 7 from when the control air starts to flow until the through-hole 12 is closed. Then, when the through hole 12 is covered with the cable 19 by the contact of the expanding bush 9 with the cable 19, the outflow of control air from the through hole 12 stops, and the flow rate detected by the flow rate sensor 16 rapidly decreases. . When the flow rate detected by the flow rate sensor 16 becomes equal to or less than the specified value, the system control unit 18 determines that the gripping of the cable 19 has been completed, and stops the expansion of the bush 9. When the expansion of the bush 9 is stopped in a state where the through hole 12 is covered with the cable 19, the cable 19 is applied to the fingers 4 and 4 by the bush 9 with appropriate strength (an example of “first strength” in the present application). It is in a state where it is held down. The expansion of the bush 9 can be stopped by interrupting or reducing the flow of the control air supplied to the presser 7 by the flow / pressure controller 15. The system control unit 18 stops the expansion of the bush 9 when the flow rate detected by the flow rate sensor 16 becomes equal to or less than a specified value. For example, when a pressure sensor is provided in addition to the flow rate sensor 16, The expansion of the bush 9 may be stopped when the flow rate detected by the sensor 16 is equal to or less than a specified value and the pressure sensor reaches an appropriate pressure.

  After the cable 19 is gripped, the robot controller 17 positions the cable 19 (S105). FIG. 11 is a diagram showing how the cable 19 is positioned. After the cable 19 is gripped, the robot controller 17 moves the robot hand 3 with the robot arm 2 so that the cable 19 moves to a position determined in the operation procedure of the electronic device to which the cable 19 is assembled. Since the cable 19 is pressed against the fingers 4 and 4 by the presser 7, the cable 19 is properly positioned without sliding the fingers 4 and 4 while the robot hand 3 is moved by the robot arm 2.

  After the positioning of the cable 19, the robot controller 17 routes the cable 19 while sliding the cable 19 with respect to the fingers 4 and 4 (S106). FIG. 12 is a diagram showing how the cable 19 is routed. After the positioning of the cable 19 is performed, the robot controller 17 issues a command to the system control unit 18 to reduce the gripping force of the robot hand 3, and the robot controller 17 causes the cable 19 to be routed along a predetermined route. Move arm 2. The system control unit 18 that has received the command from the robot controller 17 lowers the internal pressure of the presser 7 and slightly contracts the bush 9. When the expanded bush 9 contracts slightly, the cable 19 is pressed against the fingers 4 and 4 with an appropriate strength (an example of the “second strength” in the present application) which is lower than that in the step S105. become. That is, when the internal pressure of the holder 7 decreases, the force applied to the cable 19 from the holder 7 decreases, and the gripping force of the robot hand 3 decreases. When the gripping force of the robot hand 3 decreases, the robot arm 2 can pull the cable 19 around the fingers 4 while sliding the cable 19. The internal pressure of the presser 7 is reduced, for example, by slightly exhausting the control air remaining in the presser 7 to the outside of the system using an air release valve or by further reducing the flow rate of the control air flowing to the presser 7. be able to. In order to reduce the internal pressure of the retainer 7 by exhausting the control air remaining in the retainer 7 to the outside of the system using an air release valve or the like, for example, the air release valve may be opened for a specified time by a timer, or If there is a pressure sensor for measuring the internal pressure of the presser 7, the air release valve may be opened and closed based on the output of the pressure sensor.

  After the routing of the cable 19 is completed, the robot controller 17 issues a command to the system control unit 18 to release the held cable 19. When the robot controller 17 issues a command to release the cable 19 to the system controller 18, the flow / pressure controller 15 stops the control air sent to the presser 7, and the actuator 5 operates to operate the fingers 4, 4. Opens between. When the flow / pressure controller 15 stops the control air sent into the presser 7, the bush 9 that has swelled outward shrinks.

  With the robot hand 3 described above, since the force for gripping the cable 19 can be adjusted by the expansion of the bush 9, it is possible to cope with cables having various diameters. Therefore, the robot 1 provided with the robot hand 3 can appropriately adjust the gripping force of the cable 19 to position and route the cable.

  FIG. 13 is a diagram illustrating an operation state of the robot hand 103 according to the comparative example. As shown in FIG. 13A, the robot hand 103 according to the comparative example has two fingers 104, 104 and an opening / closing actuator 105K that opens and closes between the fingers 104, 104, similarly to the robot hand 3 of the above embodiment. And The robot hand 103 includes an elastic body 107 for pressing the cable 19 enclosed between the two fingers 104, 104 against the fingers 104, 104, and a linear motion actuator 105C for moving the elastic body 107.

  The robot hand 103 according to the comparative example closes the fingers 104 and 104 with the cable 19 between the fingers 104 and holds the cable 19 (see FIG. 13B). Then, the elastic body 107 is moved to press the cable 19 against the fingers 104, 104.

  In the robot hand 103 according to the comparative example, when the gripping force of the cable 19 is to be changed, the position of the elastic body 107 is adjusted by the linear motion actuator 105C. When the elastic body 107 in contact with the cable 19 moves toward the cable 19, the elastic body 107 is further compressed, and the force of the elastic body 107 pressing the cable 19 increases. As the force of the elastic body 107 pressing the cable 19 increases, the gripping force of the cable 19 increases. Further, when the elastic body 107 in contact with the cable 19 moves to the side opposite to the cable 19 side, the compression of the elastic body 107 is weakened, and the force of the elastic body 107 pressing the cable 19 is weakened. When the force of the elastic body 107 pressing the cable 19 becomes weak, the gripping force of the cable 19 decreases. That is, the gripping force of the cable 19 depends on the positional relationship between the pressed portion of the cable 19 and the elastic body 107. Therefore, when the robot hand 103 handles cables 19 having various diameters, the positional relationship between the pressed portion of the cable 19 and the elastic body 107 changes depending on the diameter of the cable 19, and the gripping force of the cable 19 is directly moved. It is difficult to properly adjust the operation amount of the actuator 105C.

  FIG. 14 is a diagram showing a positional relationship between the size of the diameter of the cable 19 and the elastic body 107. The position where the elastic body 107 contacts the cable 19 differs depending on the diameter of the cable 19. Therefore, when it is desired that the robot hand 103 grip the cables 19 having various diameters with an appropriate gripping force, the operation amount of the linear motion actuator 105C is adjusted according to the diameter of the cable 19 to be gripped. Therefore, it is difficult to control the robot hand 103.

  On the other hand, since the robot hand 3 of the above embodiment employs a mechanism for pressing the cable 19 with the bush 9, even when handling cables 19 having various diameters, the gripping force of the cable 19 is reduced. Fine adjustment can be made appropriately based on the flow rate of the control air sent to the presser 7. FIG. 15 is a diagram illustrating the relationship between the diameter of the cable 19 and the pressed state of the bush 9. In the case of the bush 9 which is expanded by the control air sent to the presser 7, the bush 9 adheres to the cable 19 while deforming along the outer peripheral surface of the cable 19. Therefore, the bush 9 can be in close contact with the cables 19 having various diameters, and the gripping force of the cables 19 can be adjusted with the control air.

In the above embodiment, the through holes 12 are provided in the bush 9, but the through holes 12 may be omitted. When the through-hole 12 is omitted, the system control unit 18 adjusts the strength of the force that presses the cable 19 by, for example, expanding and contracting the bush 9 while monitoring the internal pressure of the presser 7 with a pressure sensor. Alternatively, the bush 9 may be expanded and contracted while measuring the force applied to the cable 19 with the load sensors provided on the fingers 4 and 4.

  Further, the robot hand 3 of the above embodiment can be modified as follows. FIG. 16 is a view showing a modification of the bush 9. In the robot hand 3 of the above embodiment, the bush 9 may be provided with a plurality of through holes 12 along the longitudinal direction of the cable 19. For example, when four through holes 12A, 12B, 12C, and 12D are provided in the bush 9 along the longitudinal direction of the cable 19 as in a modification shown in FIG. 16, the following control can be performed. .

  FIG. 17 is a diagram showing a contact state between a bush 9 and a cable 19 according to a modification. If the bulge of the bush 9 is large, the portion of the bush 9 that comes into contact with the cable 19 is large, so that all four through holes 12A, 12B, 12C, and 12D are closed by the cable 19 as shown in FIG. It will be in a state where it was lost. Also, if the bulge of the bush 9 is small, the portion of the bush 9 that contacts the cable 19 is small. For example, as shown in FIG. 17B, one of the four through holes 12A, 12B, 12C, and 12D is formed. The part is closed by the cable 19, and air leaks from the other part. Therefore, when the bush 9 is provided with the four through holes 12A, 12B, 12C, and 12D, the system control unit 18 determines the contact state of the bush 9 with the cable 19 based on the flow rate of the flow rate sensor 16. Can be. For example, the flow sensor 16 has four through-holes 12A, 12B, 12C, and 12D when a part of the four through-holes 12A, 12B, 12C, and 12D is closed by the cable 19 and air leaks from the other. 12D shows a higher flow rate than if none of the cables 19 were covered. When the four through holes 12A, 12B, 12C, and 12D are all covered with the cable 19, the flow sensor 16 partially blocks the four through holes 12A, 12B, 12C, and 12D with the cable 19. It shows a lower flow rate than when air is leaking from others. Therefore, the system control unit 18 adjusts the control amount of the flow rate / pressure controller 15 while grasping the contact state of the bush 9 based on the output of the flow rate sensor 16 to thereby control the four through holes 12A, 12B, 12C, A strong grip state in which 12D is completely covered by the cable 19, a light grip state in which a part of the four through holes 12A, 12B, 12C, and 12D is covered by the cable 19, and four through holes 12A, 12B, 12C, and 12D. Can be realized in a non-gripping state in which the cable 19 is not covered.

  In the above-described embodiment, the cable 19 is held by the two fingers 4 and 4. However, the cable 19 may be held by a hook-shaped finger instead of the two fingers 4 and 4. FIG. 18 is a diagram illustrating the robot hand 3 provided with hook-shaped fingers 4 and 4 instead of the two fingers 4 and 4. Instead of the two fingers 4 and 4, the robot hand 3 may include a hook-shaped finger 24 obtained by bending the tip of a rod-shaped member to the side. Even if the robot hand 3 has hook-shaped fingers 24 instead of the two fingers 4, 4, a relatively large-diameter cable 19 (see FIG. 18A) and a relatively small-diameter cable 19 (see FIG. 18A). 18B) can be gripped while pressing against the finger 24 with various strengths.

This application includes the following supplementary matters.
(Appendix 1)
A hand having a finger capable of hanging a cable to be gripped,
A press that can press the cable that spans the finger against the finger,
The strength of the force with which the press presses the cable is used as the first strength used when the hand grips the cable, and when the cable is pulled around by the hand while sliding against the finger. Control means that can be adjusted to a second intensity that is lower than the first intensity.
Robot hand.
(Appendix 2)
The presser has a hollow portion and an elastic body forming at least a part of the hollow portion,
The control means adjusts the strength by increasing or decreasing the internal pressure of the hollow portion,
The robot hand according to supplementary note 1.
(Appendix 3)
The elastic body has a through hole at a portion where the cable contacts,
The control means adjusts the intensity based on a flow rate of the gas flowing to the hollow portion,
The robot hand according to attachment 2.
(Appendix 4)
The elastic body has a plurality of the through holes along a longitudinal direction of the cable,
The robot hand according to attachment 3.
(Appendix 5)
Hang the cable on the finger of the hand capable of hanging the cable to be gripped,
Pressing the cable hanging on the finger with the finger by pressing the cable;
The strength of the force with which the presser presses the cable is used for the first strength used when the hand grips the cable, and when the cable is pulled around by the hand while sliding on the finger. Adjusting to a second intensity weaker than the first intensity,
How to handle the cable.
(Appendix 6)
The presser has a hollow portion and an elastic body forming at least a part of the hollow portion,
When adjusting the strength of the force that the press presses on the cable, adjust the strength by increasing or decreasing the internal pressure of the hollow portion,
A method for processing a cable according to claim 5.
(Appendix 7)
The elastic body has a through hole at a portion where the cable contacts,
When adjusting the strength of the force that the press presses the cable, the strength is adjusted based on the flow rate of gas flowing into the hollow portion,
A method for manipulating a cable according to supplementary note 6.
(Appendix 8)
The elastic body has a plurality of the through holes along a longitudinal direction of the cable,
The method for manipulating a cable according to supplementary note 7.

1. Robot: 2 Robot arm: 3, 103 Robot hand: 4, 24, 104 Finger: 5 Actuator: 105K Opening / closing actuator: 105C Linear actuator: 6 Claw : 7 ··· Hold down: 107 · · Elastic body: 8 · · · Cylindrical member: 9 · · · Bush: 10 · · · Hollow portion: 11 · · Inflow holes: 12, 12A, 12B, 12C, 12D · · Through holes: 13. Control system: 14 Actuator control unit: 15 Flow rate / pressure controller: 16 Flow rate sensor: 17 Robot controller: 18 System control unit: 19 Cable: 1A1 1 arm: 1A2 2nd arm: 1B Base: 1K1 1st joint: 1K2 2nd joint: 1K3 3rd joint

Claims (5)

A hand having a finger capable of hanging a cable to be gripped,
A press that can press the cable that spans the finger against the finger,
The strength of the force with which the press presses the cable is used as the first strength used when the hand grips the cable, and when the cable is pulled around by the hand while sliding against the finger. Control means that can be adjusted to a second intensity that is lower than the first intensity .
The hand forms an enclosure that surrounds the cable by opening and closing the fingers each provided at the tip with claws that are inclined obliquely,
Robot hand. The presser has a hollow portion and an elastic body forming at least a part of the hollow portion,
The control means adjusts the strength by increasing or decreasing the internal pressure of the hollow portion,
The robot hand according to claim 1. The elastic body has a through hole at a portion where the cable contacts,
The control means adjusts the intensity based on a flow rate of the gas flowing to the hollow portion,
The robot hand according to claim 2. The elastic body has a plurality of the through holes along a longitudinal direction of the cable,
The robot hand according to claim 3. Hang the cable on the finger of the hand capable of hanging the cable to be gripped,
Pressing the cable hanging on the finger with the finger by pressing the cable;
The strength of the force with which the press presses the cable is used as the first strength used when the hand grips the cable, and when the cable is pulled around by the hand while sliding against the finger. Adjusting to a second intensity that is weaker than the first intensity ,
In the step of laying the cable on the finger of the hand, the hand forms an enclosure surrounding the cable by opening and closing the fingers each provided with a slanted claw at the tip,
How to handle the cable.

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