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Title:
EVERTING END EFFECTOR FOR USE WITH AN ARTICULATED ARM IN A ROBOTIC SYSTEM
Document Type and Number:
WIPO Patent Application WO/2017/048942
Kind Code:
A1
Abstract:
An end effector is disclosed for an articulated arm in a robotic system. The end effector includes an enclosed flexible membrane generally in the form of an annulus that contains a fluid within the membrane.

Inventors:
WAGNER THOMAS (US)
AHEARN KEVIN (US)
DAWSON-HAGGERTY MICHAEL (US)
GEYER CHRISTOPHER (US)
KOLETSCHKA THOMAS (US)
MARONEY KYLE (US)
MASON MATTHEW (US)
PRICE GENE TEMPLE (US)
ROMANO JOSEPH (US)
SMITH DANIEL (US)
SRINIVASA SIDDHARTHA (US)
VELAGAPUDI PRASANNA (US)
ALLEN THOMAS (US)
Application Number:
PCT/US2016/051922
Publication Date:
March 23, 2017
Filing Date:
September 15, 2016
Export Citation:
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Assignee:
BERKSHIRE GREY INC (US)
International Classes:
B25J15/00; B65G47/90
Foreign References:
DE102005018207A12006-10-26
US6846029B12005-01-25
US20040169386A12004-09-02
Other References:
None
Attorney, Agent or Firm:
HILTON, William et al. (US)
Download PDF:
Claims:
CLAIMS

1. An end effector for an articulated arm in a robotic system, said end effector comprising an enclosed flexible membrane generally in the form of an annulus that contains a fluid within the membrane.

2. The end effector as claimed in claim 1, wherein a portion of the enclosed flexible membrane is attached to the articulated arm.

3. The end effector as claimed in claim 1, wherein said enclosed flexible membrane is in the form of a tubular annulus.

4. The end effector as claimed in claim 3, wherein said tubular annulus is attached on an outer surface thereof to an outer collar that is attached to the articulated arm.

5. The end effector as claimed in claim 4, wherein the tubular annulus includes a distal end for engaging objects.

6. The end effector as claimed in claim 4, wherein the end effector includes a linear actuator that is positioned for reciprocal movement within the tubular annulus.

7. The end effector as claimed in claim 6, wherein the linear actuator includes a distal portion that is attached to the tubular annulus.

8. The end effector as claimed in claim 4, wherein the end effector includes a vacuum source for providing a vacuum within the tubular annulus.

9. The end effector as claimed in claim 8, wherein the vacuum is provided through a linear actuator that is positioned for reciprocal movement within the tubular annulus

10. The end effector as claimed in claim 8, wherein the end effector further includes a positive air pressure source for selectively providing positive air pressure within the tubular annulus to urge an object to move away from the end effector.

11. A method of engaging an object by an articulated arm of a robotic system, said method comprising the steps of positioning near an object to be engaged, an enclosed flexible membrane that contains a fluid and is generally in the form of an annulus, and engaging the object with the enclosed flexible membrane.

12. The method as claimed in claim 11, wherein said enclosed flexible membrane is in the form of a tubular annulus.

13. The method as claimed in claim 11, wherein the tubular annulus includes a distal end for engaging objects.

14. The method as claimed in claim 13, wherein the method further includes the step of moving a linear actuator within the tubular annulus.

15. The method as claimed in claim 11, wherein the method further includes the step of providing a vacuum within the tubular annulus.

16. The method as claimed in claim 15, wherein the method further includes the step of providing positive air pressure within the tubular annulus to urge an object to move away from the tubular annulus.

17. An end effector for an articulated arm in a robotic system, said end effector comprising a tubular annulus, wherein objects may be grasped by an inside of the tubular annulus.

18. The end effector as claimed in claim 17, wherein the tubular annulus includes gripping elements on an outer surface of the tubular annulus.

19. The end effector as claimed in claim 18, wherein the gripping elements include lands.

20. The end effector as claimed in claim 18, wherein the gripping elements include flexible cups.

21. The end effector as claimed in claim 18, wherein the gripping elements include cleats.

Description:
PRIORITY

The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/218,799 filed September 15, 2015, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

The invention generally relates to robotic systems, and relates in particular to robotic systems that include articulated arms with end effectors for securing objects to the articulated arms in such a manner that they can be easily released by the end effector.

There are numerous end effectors (or grippers) commonly employed for industrial automation and other applications, including vacuum grippers, parallel jaw grippers, angular jaw grippers, and many others.

Vacuum grippers typically employ vacuum sources to evacuate a vacuum cup which is pressed onto a hard smooth surface to obtain a good seal. Gripping soft surfaces such as bagged products is more challenging, but in some instances a bag gripper may obtain a good seal with a plastic bag in order to lift it.

Parallel jaw and angular jaw grippers are sometimes used in industrial processes. Besides lifting and moving parts, they may be used to move a part to a precise location for high-tolerance mechanical assembly operations.

Magnetic grippers are also commonly employed, when a ferrous material is involved. In addition, there are many special purpose grippers suited to particular applications, such as internal chuck collets to grasp gears and wheels, or arrays of needles to grasp sheets of cloth.

A class of soft grippers has also been developed in research labs, and one example is the "Jamming Gripper" developed by a consortium that includes iRobot, Cornell University, and Empire Robotics. The Jamming Gripper includes a granular material enclosed in a soft bag, that conforms to an object shape and then stiffens when the air is evacuated from the bag.

A similar product is the Festo FlexShapeGripper sold by Festo Corporation that employs eversion of a flexible membrane to grasp an object. Such a system however, may not be suitable for certain applications, such as grasping a wide variety of packaging materials.

There remains a need, therefore, for an end effector that more is versatile enough to be used on a wide variety of objects.

SUMMARY

In accordance with an embodiment, the invention provides an end effector for an articulated arm in a robotic system. The end effector includes an enclosed flexible membrane generally in the form of an annulus that contains a fluid within the membrane.

In accordance with another embodiment, the invention provides a method of engaging an object by an articulated arm of a robotic system. The method includes the steps of positioning near an object to be engaged, an enclosed flexible membrane that contains a fluid and is generally in the form of an annulus, and engaging the object with the enclosed flexible membrane.

In accordance with a further embodiment, the invention provides an end effector for an articulated arm in a robotic system. The end effector includes a tubular annulus, wherein objects may be grasped by an inside of the tubular annulus.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description may be further understood with reference to the accompanying drawings in which: Figure 1 shows an illustrative diagrammatic view of a robotic system that includes an end effector in accordance with an embodiment of the present invention;

Figures 2A and 2B show illustrative diagrammatic views of the end effector of Figure 1 in an initial position (Figure 2A) and in an engaged position (Figure 2B) with respect to an object;

Figure 3 shows an illustrative diagrammatic view of an end effector in accordance with another embodiment of the present invention involving an outer sleeve actuator;

Figures 4A - 4C show illustrative diagrammatic views of end effector in accordance with further embodiments of the present invention involving gripping elements on an exposed surface of the tubular annulus;

Figures 5A and 5B show illustrative diagrammatic views of the end effector in accordance with a further embodiment of the present invention that includes a vacuum source in an initial position (Figure 5A) and in an engaged position (Figure 5B) with respect to an object; and

Figures 6A and 6B show illustrative diagrammatic views of the end effector in accordance with a further embodiment of the present invention that includes a vacuum source in an initial position (Figure 6A) and in an engaged position (Figure 6B) with respect to an object that is a bag of item.

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION

In accordance with an embodiment, the invention provides an enveloping gripper that grips a broad range of shapes and materials via compression and eversion of a compliant material structure in contact with the object to be grasped. In certain embodiments, the system additionally provides a vacuum source to prime the grasping process. The system Figure 1 shows an illustrative diagrammatic view of a robotic system that includes an end effector in accordance with an embodiment of the present invention;

Figures 2A and 2B show illustrative diagrammatic views of the end effector of Figure 1 in an initial position (Figure 2A) and in an engaged position (Figure 2B) with respect to an object;

Figure 3 shows an illustrative diagrammatic view of an end effector in accordance with another embodiment of the present invention involving an outer sleeve actuator;

Figure 4 shows an illustrative diagrammatic view of an end effector in accordance with further embodiments of the present invention involving gripping elements on an exposed surface of the tubular annulus;

Figures 5A and 5B show illustrative diagrammatic views of the end effector in accordance with a further embodiment of the present invention that includes a vacuum source in an initial position (Figure 5A) and in an engaged position (Figure 5B) with respect to an object; and

Figures 6A and 6B show illustrative diagrammatic views of the end effector in accordance with a further embodiment of the present invention that includes a vacuum source in an initial position (Figure 6A) and in an engaged position (Figure 6B) with respect to an object that is a bag of item.

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION

In accordance with an embodiment, the invention provides an enveloping gripper that grips a broad range of shapes and materials via compression and eversion of a compliant material structure in contact with the object to be grasped. In certain embodiments, the system additionally provides a vacuum source to prime the grasping process. The system tubular annulus to roll upon itself in directions as indicated at B, while the opposing end of the tubular annuls will roll upon itself in directions as indicated at C. While the tubular annulus 24 undergoes this process of everting, it remains attached to the outer collar 26 at the attachment 28. By controlling the movement of the tubular annulus as described above, the end effector may be used to draw an object 32 into the tubular annulus and hold it within the tubular annulus until the linear actuator is moved in a direction that is opposite the direction indicated at A (and the object 32 is discharged). As also shown in Figure 2B, the tubular annulus is formed of a flexible material that may conform to the shape of the object 32 being grasped. The fluid within the tubular annulus may be water or may be selected to have a particular viscosity.

Figure 3 shows another embodiment of the invention similar to the embodiment of Figures 2A and 2B, except that the outer collar 26 is moved relative the rod 30. In particular, the outer collar 26 is attached (as shown at 34) to a collar actuator 36. When the collar actuator 36 is moved in a direction as shown at D with respect to the rod 30, the inner surface of the collar 26 will cause the tubular annulus 24 to roll (as shown at B and C) such that the object 32 may be grasped within the tubular annulus 24.

Figure 4A shows a further embodiment of the present invention in which the tubular annulus 24 includes gripping elements 38 that are provided on the outer surface of the tubular annulus 24. As the tubular annulus 24 draws the object 32 into the tubular annulus, the gripping elements 38 on the tubular annulus facilitate the capture and retention of the object 32. In accordance with various embodiments, and with reference to Figure 4A, the gripping elements may be raised lands that may be either ordered or randomly distributed on the outer surface of the tubular annulus 24. As shown in Figure 4B, in accordance with another embodiment, the gripping elements may be small flexible cups (suction cups) 38', and as shown in Figure 4C, the gripping elements may be in the form of cleats 38". In any of these tubular annulus to roll upon itself in directions as indicated at B, while the opposing end of the tubular annuls will roll upon itself in directions as indicated at C. While the tubular annulus 24 undergoes this process of everting, it remains attached to the outer collar 26 at the attachment 28. By controlling the movement of the tubular annulus as described above, the end effector may be used to draw an object 32 into the tubular annulus and hold it within the tubular annulus until the linear actuator is moved in a direction that is opposite the direction indicated at A (and the object 32 is discharged). As also shown in Figure 2B, the tubular annulus is formed of a flexible material that may conform to the shape of the object 32 being grasped. The fluid within the tubular annulus may be water or may be selected to have a particular viscosity.

Figure 3 shows another embodiment of the invention similar to the embodiment of Figures 2A and 2B, except that the outer collar 26 is moved relative the rod 30. In particular, the outer collar 26 is attached (as shown at 34) to a collar actuator 36. When the collar actuator 36 is moved in a direction as shown at D with respect to the rod 30, the inner surface of the collar 26 will cause the tubular annulus 24 to roll (as shown at B and C) such that the object 32 may be grasped within the tubular annulus 24.

Figure 4 shows a further embodiment of the present invention in which the tubular annulus 24 includes gripping elements 38 that are provided on the outer surface of the tubular annulus 24. As the tubular annulus 24 draws the object 32 into the tubular annulus, the gripping elements 38 on the tubular annulus facilitate the capture and retention of the object 32. In accordance with various embodiments, and with reference to Figure 4, the gripping elements may be raised lands that may be either ordered or randomly distributed on the outer surface of the tubular annulus 24. In accordance with another embodiment, the gripping elements 38 may be small flexible cups (suction cups), and in further embodiments, the gripping elements 38 may be in the form of cleats. In any of these annulus material, and this may induce compression wrinkles in the object fabric, intimately intermingling the fabrics so that friction assists in drawing the object fabric into the cavity.

Those skilled in the art will appreciate that numerous modifications and variations may be made to the above disclosed embodiments without departing from the spirit and scope of the present invention.

What is claimed is: