WO2022163654A1

WO2022163654A1 - Grasping apparatus and grasping method

Info

Publication number: WO2022163654A1
Application number: PCT/JP2022/002701
Authority: WO
Inventors: 英史松井; 耕一反田; 明宏細川
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2021-01-28
Filing date: 2022-01-25
Publication date: 2022-08-04
Also published as: JP2022115513A

Abstract

A hand unit 3 as a grasping apparatus comprises: a finger 2 for grasping an object; a drive unit 1 that drives the finger 2; a plate spring 9 that, when the finger 2 is grasping the object, biases the finger 2 in a direction of grasping the object; and a lock device 7 that, when the finger 2 is grasping the object, prevents the finger 2 from moving in a direction of releasing the object.

Description

Gripping device and gripping method

The present disclosure relates to a gripping device and gripping method for gripping an object.

The robot hand described in Patent Document 1 includes a coil spring that can be elastically deformed in a direction that intersects the extending direction of the fingers when the fingers grip an object. As a result, even when the object to be gripped is made of a fragile material, a soft material, or the like, the object can be gripped well.

WO2019/176802

However, with the robot hand described in Cited Document 1, it is difficult to estimate the deformation of the coil spring that grips the object, the grip surface is unstable, and it is difficult to accurately grip a specific position. Also, a soft object such as cloth may get caught in the coil spring. The inventors of the present invention recognized that it is a problem to suppress these problems and realize a gripping device with higher performance, and came up with the gripping device of the present disclosure.

The present disclosure provides techniques for improving the performance of a gripping device that grips an object.

The gripping device according to the present disclosure includes a finger portion for gripping an object, a drive portion for driving the finger portion, and a finger portion that moves in a direction to grip the object while the finger portion is gripping the object. An urging part for urging and a release restraining part for restraining the fingers from moving in the direction of releasing the object when the fingers are gripping the object.

A gripping method according to the present disclosure is a method for gripping an object with the above-described gripping device, comprising steps of controlling the drive unit to grip the object with the fingers; , stopping the drive.

According to the technology of the present disclosure, it is possible to improve the performance of a gripping device that grips an object.

FIG. 2 is a diagram schematically showing the configuration of a hand unit according to Embodiment 1; FIG. 2 is a diagram schematically showing the configuration of a hand unit according to Embodiment 1; Central cross-sectional view of the hand portion according to the first embodiment FIG. 4 is a diagram showing a connecting portion between a driving portion and a finger of the hand portion according to Embodiment 1; 4 is a flow chart showing a procedure of a method for controlling a hand unit according to the first embodiment; 4A and 4B are diagrams showing a procedure of a method for holding the hand portion according to the first embodiment;

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially the same configurations may be omitted.

It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Embodiment 1 will be described below with reference to FIGS.

[1-1. Constitution]
1A and 1B schematically show the configuration of a hand section 3 as an example of a gripping device according to Embodiment 1. FIG. 1A is a front view of the hand portion 3, and FIG. 1B is a side view of the hand portion 3. FIG. The hand section 3 is composed of two fingers 2 facing each other for holding an object, and a driving section 1 for opening and closing the fingers 2 . The drive unit 1 rotates and opens and closes the two fingers 2 facing each other in conjunction with each other. Note that the hand portion 3 may have three or more fingers 2 .

FIG. 2 is a central sectional view of the hand portion 3 according to Embodiment 1. FIG. The drive unit 1 includes a motor 4 , a reduction gear 5 , a torque limiter 6 , a locking device 7 and a reduction gear 8 . These components are housed in the gear case 16 . The gear case 16 is covered with a gear case cover 17 . The drive unit 1 is controlled by a control device 23 .

The finger 2 includes a leaf spring 9, a finger cover A10, a finger cover B11, and a contact portion 22. The leaf spring 9 is covered with a finger cover A10 and a finger cover B11. The contact portion 22 includes a spring bearing 12 , a spring 13 , a turntable 14 and an elastic body 15 .

The rotation of the motor 4 is reduced by the reduction gear 8 and transmitted to the finger 2 . The finger 2 is composed of a plate spring 9 whose base portion fixed to the last reduction gear 8 bends in the opening/closing direction. That is, the leaf spring 9 urges the finger 2 in the direction of gripping the object while the finger 2 is gripping the object. As a result, it is possible to prevent an excessive load from being applied to the object to be gripped, and to grip the object with an appropriate load. In addition, even if the object is a flexible object, the leaf spring 9 bends only in the opening/closing direction according to the object and does not move in the other direction, so that the object can be gripped more securely.

The locking device 7 functions as a release restraining section that restrains the fingers 2 from moving in the direction of releasing the object while the fingers 2 are gripping the object. The locking device 7 locks the rotation of the motor 4, the reduction gear 5, the reduction gear 8, or the finger 2 so that the finger 2 does not rotate in the opening direction. As a result, even if the motor 4 is stopped after gripping the object, the gripping state of the object can be maintained, so that vibration, noise, power consumption, and the like can be reduced. Moreover, since the load on the drive unit 1 and the like can be reduced, the life of the hand unit 3 can be lengthened.

When the motor 4 is stopped while the finger 2 is gripping the object, even if the rotation of the finger 2 in the opening direction is locked by the lock device 7, the backlash of the reduction gear 5, the reduction gear 8, etc. , the finger 2 can rotate slightly in the opening direction. In the hand portion 3 of the present embodiment, the leaf spring 9 biases the finger 2 so that the object is not released even if the finger 2 moves in the direction of releasing the object by the backlash. This allows the object to be gripped more reliably.

The leaf spring 9 urges the finger 2 so that the object is not released when the object is pulled out together with another member after gripping the object. For example, when an object such as clothing is once held by the fingers 2 together with the work plate placed thereon, and then the object is pulled out from a member such as the work plate while being held, the biasing force of the leaf spring 9 causes the finger 2 to move the object. can be automatically closed by the thickness of the work plate, the object can be continuously gripped without further operating the motor 4.例文帳に追加

The torque limiter 6 limits the torque of the motor 4 so that it does not exceed a predetermined value. As a result, the object can be stably gripped with a constant clamping force without providing detection means such as a tactile sensor at the fingertip. Therefore, even if the size and thickness of the object are different, the object can be stably gripped without complicated control.

The predetermined value is, for example, when the finger 2 moves in the direction of releasing the object due to backlash in the drive unit 1, or when the member gripped together with the object is pulled out, and the like. is the value of torque that can be applied to prevent the object from releasing. After the fingers 2 have gripped the object and before the motor 4 is stopped, the plate spring 9 is used to provide a margin for the fingers 2 to rotate in the opening direction or to reduce the thickness of the gripped object. By energizing the fingers 2 in advance, the object can be stably gripped without complicated control. The predetermined values are the spring constant, material, size, and shape of the leaf spring 9, the backlash of the reduction gear 5 or the reduction gear 8, the type, material, size, and shape of the object, the type and material of the member gripped together with the object, It is set in advance according to size, shape, and the like.

The contact portion 22 is provided at the tip portion of the finger 2 . A spring bearing 12 is fixed inside the finger 2 . One end of the spring 13 is fixed to the spring receiver 12, and the other end elastically supports the turntable 14 so as to be rotatable. The elastic body 15 is fixed to the turntable 14 and comes into contact with the object when the object is gripped. The connecting surfaces of the spring bearing 12 fixed to the finger 2 and the turntable 14 respectively have concave and convex shapes that are slidable relative to each other. The turntable 14 is rotatable relative to the finger 2 by sliding on the connecting surface. As a result, even if the object rotates in the gravity direction due to the rotation of the hand part 3, the contact part 22 can be rotated and whirled, so that twisting of the object can be suppressed. .

FIG. 3 shows a connecting portion between the driving portion 1 and the finger 2 of the hand portion 3 according to the first embodiment. A finger fixing base 19 is fixed to the final reduction gear 8 or its rotating shaft 18 . Finger 2 is fixed to finger fixing base 19 by fixing screw 20 and washer 21 .

[1-2. motion]
The operation and function of the hand unit 3 configured as described above will be described below.

FIG. 4 is a flow chart showing the procedure of the control method for the hand unit 3 according to the first embodiment. Before gripping the object, the hand part 3 is moved to a position where the fingers 2 can grip the object. The controller 23 drives the motor 4 to rotate the fingers 2 in the closing direction (S10). After the fingers 2 have gripped the object (S12), the controller 23 further drives the motor 4 to bias the leaf spring 9 until the torque limiter 6 is activated (S14). The controller 23 locks the rotation of the finger 2 in the opening direction by the lock device 7 (S16), and stops the motor 4 (S18). If the locking device 7 is a mechanism that locks the rotation of the finger 2 in the opening direction and allows the rotation in the closing direction, the control device 23 can rotate the locking device 7 at an arbitrary timing until the motor 4 is stopped. may be activated. If the locking device 7 is a mechanism that locks not only the rotation of the fingers 2 in the opening direction but also the rotation in the closing direction, the control device 23 controls the time from the activation of the torque limiter 6 until the motor 4 is stopped. The locking device 7 may be actuated in the meantime.

FIG. 5 is a diagram showing a procedure of a method for gripping clothes by the hand portion 3 according to the first embodiment. For example, a single T-shirt 24, which is the object's clothing, is folded in two and hung on the work plate 25, which is the placing portion. The control device 23 lowers the two hands 3 with the fingers 2 open to both ends of the T-shirt 24 and grips the T-shirt 24 together with the working plate 25 with a predetermined torque (S20). Then, the control device 23 raises the two hand parts 3 while the fingers 2 are holding the T-shirt 24, and pulls the T-shirt 24 out of the working plate 25 (S22).

At this time, the finger 2 automatically closes by the thickness of the work plate 25 due to the biasing force of the plate spring 9, and continues to hold the T-shirt 24. Thereby, the hand part 3 can grip only the T-shirt 24 folded in two. Note that this operation is a polite gripping method for folding the T-shirt 24 in two, but one hand portion 3 may simply pull up the T-shirt 24 from the work plate 25 .

[1-3. effects, etc.]
As described above, in the present embodiment, the hand section 3 includes the fingers 2 for gripping the object, the driving section 1 for driving the fingers 2, and when the fingers 2 are gripping the object, A leaf spring 9 for biasing the fingers 2 in the direction of gripping the object, and a locking device 7 for suppressing the movement of the fingers 2 in the direction of releasing the object while the fingers 2 are gripping the object. Prepare. Accordingly, even if the drive unit 1 is stopped after gripping the object, the gripped state of the object can be maintained. Also, even if the object is a flexible object, it can be properly gripped.

Further, in the present embodiment, the drive unit 1 includes a motor 4 that rotationally drives the finger 2, and the lock device 7 locks the finger 2 so that it does not rotate in the direction of releasing the object. As a result, the hand unit 3 capable of maintaining the state of gripping the object even when the drive unit 1 is stopped after gripping the object can be realized with a simple configuration.

In addition, in the present embodiment, the leaf spring 9 keeps the object even if the fingers 2 move in the direction of releasing the object due to backlash in the drive unit 1 while the fingers 2 are gripping the object. The finger 2 is biased so that the object is not released. This allows the object to be gripped more reliably.

Also, in this embodiment, the leaf spring 9 urges the fingers 2 so that the object is not released when the object is pulled out after gripping the object together with another member. As a result, the gripping state of the object can be maintained without further driving the driving unit 1 .

In addition, in the present embodiment, the drive unit 1 includes a motor 4 that rotationally drives the finger 2, and the hand unit 3 further includes a torque limiter 6 that limits the torque of the motor 4 so that it does not exceed a predetermined value. As a result, the object can be stably gripped with a constant clamping force.

In the present embodiment, the predetermined value is set when the finger 2 moves in the direction of releasing the object due to backlash in the drive unit 1, or when the member gripped together with the object is pulled out. It is the torque value at which the leaf spring 9 can bias the finger 2 so that the object is not released. This allows the object to be gripped more reliably.

In the present embodiment, the hand portion 3 further includes a contact portion 22 that is provided at the end of the finger 2 and contacts the object when the object is gripped. respectively have concave and convex shapes that are slidable relative to each other, and the contact portion 22 is rotatable with respect to the finger 2 by sliding on the connecting surface. As a result, even if the object rotates in the gravity direction due to the rotation of the hand part 3, the contact part 22 can be rotated and whirled, so that twisting of the object can be suppressed. .

In the present embodiment, the gripping method for gripping the object with the hand portion 3 includes the step of gripping the object with the fingers 2 by controlling the motor 4, and the step of gripping the object with the fingers 2. and a step of stopping the motor 4 afterwards. As a result, even if the motor 4 is stopped after gripping the object, the gripping state of the object can be maintained, so that vibration, noise, power consumption, and the like can be reduced. Moreover, since the load on the drive unit 1 and the like can be reduced, the life of the hand unit 3 can be lengthened.

In this embodiment, the gripping method includes, before stopping the motor 4, applying a biasing force to the leaf spring 9 so that the fingers 2 grip the object while the motor 4 is stopped. Prepare more. This allows the object to be gripped more reliably.

In this embodiment, the gripping method for gripping an object with the hand portion 3 includes the steps of gripping the T-shirt 24 placed on the work plate 25 together with the work plate 25 with the fingers 2; and pulling the T-shirt 24 out of the working plate 25 after 2 has gripped the T-shirt 24 . At this time, the fingers 2 are automatically closed by the thickness of the working plate 25 due to the urging force of the plate spring 9 and continue to hold the T-shirt 24, so that the hand portion 3 only holds the T-shirt 24 folded in half. can be grasped.

As described above, Embodiment 1 has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments with modifications, replacements, additions, omissions, and the like. Also, it is possible to combine the constituent elements described in the first embodiment to form a new embodiment.

For example, although the leaf spring 9 is illustrated as an urging portion, the present invention is not limited to this. Although not shown, a hinge that rotates in the same direction as the deflection of the leaf spring 9, that is, two-dimensionally is provided, and the hinge is rotated. A configuration in which a coil spring that requires a predetermined rotational torque is provided on the rotating shaft of the hinge may be used.

It should be noted that the above-described embodiment is for illustrating the technology in the present disclosure, and various modifications, replacements, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

The present disclosure can be used for grasping devices.

DESCRIPTION OF SYMBOLS 1... Drive part 2... Finger (fingers) 3... Hand part 4... Motor 5... Reduction gear 6... Torque limiter 7... Lock device (release restraining part) 8... Reduction gear 9... Plate Spring (biasing portion) 10 Finger cover A 11 Finger cover B 12 Spring receiver 13 Spring 14 Turntable 15 Elastic body 16 Gear case 17 Gear case cover 18 Rotation shaft 19 Finger fixing base 20 Fixing screw 21 Washer 22 Contact portion 23 Control device 24 T-shirt (object) 25 Work plate (placement portion).

Claims

fingers for gripping an object;
a drive unit for driving the finger;
a biasing unit that biases the finger in a direction to grip the object when the finger is gripping the object;
a release restraining unit that restrains the finger from moving in a direction to release the object when the finger is gripping the object;
A grasping device comprising:
The driving unit includes a motor that rotationally drives the finger,
2. The grasping device according to claim 1, wherein the release restraining portion includes a locking mechanism that locks the fingers so as not to rotate in a direction to release the object.
The urging portion is adapted to hold the object even if the finger moves in a direction to release the object due to backlash in the driving portion while the finger is gripping the object. 3. A gripping device according to claim 1 or 2, wherein the fingers are biased against release.
4. The urging part urges the fingers so that the object is not released when the member is pulled out after gripping the object with another member. The gripping device according to .
The driving unit includes a motor that rotationally drives the finger,
The gripping device according to any one of claims 1 to 4, further comprising a torque limiter that limits the torque of the motor so that it does not exceed a predetermined value.
The predetermined value is set when the finger moves in a direction to release the object due to backlash in the drive unit, or when a member gripped together with the object is pulled out. 6. The gripping device of claim 5, wherein the bias is of a torque value capable of biasing the finger against release.
further comprising a contact portion provided at an end of the finger portion and in contact with the object when the object is gripped;
connecting surfaces of the finger portion and the contact portion respectively have concave and convex shapes that are slidable relative to each other;
7. The gripping device according to any one of claims 1 to 6, wherein the contact portion is rotatable with respect to the finger portion by sliding on the connecting surface.
A gripping method for gripping an object with the gripping device according to any one of claims 1 to 7,
controlling the drive unit to grip the object with the fingers;
stopping the driving unit after the finger grips the object;
A grasping method comprising:
10. The method according to claim 8, further comprising, before stopping the driving part, applying a biasing force to the biasing part so that the fingers keep gripping the object while the driving part is stopped. gripping method.
A gripping method for gripping an object with the gripping device according to any one of claims 1 to 7,
a step of gripping the object placed on the placing portion together with the placing portion by the fingers;
After the fingers have gripped the object, pulling out the object from the placement unit;
A grasping method comprising: