Apparatus for controlling stiffness of output link in moving mechanism

Patent metadata

Field	Value
Publication number	US-9902064-B2
Application number	US-201715413450-A
Country	US
Kind code	B2
Filing date	Jan 24, 2017
Priority date	Nov 19, 2014
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A stiffness control apparatus includes a base member, an output link configured to move along a plane parallel to a surface of the base member, and at least one stiffness control unit configured to control stiffness of the output link. The at least one stiffness control unit includes a shaft including a first end and a second end, the first end being rotatably coupled to the base member, a rotating member including an elongated hole into which the second end of the shaft is movably inserted, and rotatably arranged by the shaft at a position having contact with the output link on an outer side or an inner side the output link, and an elastic member between the second end of the shaft and at least one inner wall of the elongated hole in a longitudinal direction thereof.

First claim

What is claimed is:

1. An apparatus for controlling stiffness of an output link in a moving mechanism, the apparatus comprising:
a base member;
an output link configured to move along a plane parallel to a surface of the base member; and
at least one stiffness control unit configured to control stiffness of the output link and including
a shaft including a first end and a second end, the first end being rotatably coupled to the base member,
a rotating member including an elongated hole into which the second end of the shaft is movably inserted, and rotatably arranged by the shaft at a position having contact with the output link on an outer side of the output link, and
an elastic member between the second end of the shaft and at least one inner wall of the elongated hole in a longitudinal direction thereof.

2. The apparatus according to claim 1 , wherein the rotating member is configured to move in the longitudinal direction of the elongated hole by sliding of the second end of the shaft along the elongated hole.

3. The apparatus according to claim 1 , wherein
the elongated hole includes a first inner wall and a second inner wall opposite to the first inner wall with the shaft therebetween in the longitudinal direction of the elongated hole, and
the elastic member includes
a first elastic member between the first inner wall of the elongated hole and the second end of the shaft, and
a second elastic member between the second inner wall of the elongated hole and the second end of the shaft.

4. The apparatus according to claim 1 , wherein the at least one stiffness control unit is configured to produce
a maximum stiffness of the output link at a first position where the elongated hole is located in a first direction parallel to a longitudinal direction of the output link by rotating the rotating member, and
a minimum stiffness of the output link at a second position where the elongated hole is located in a second direction perpendicular to the first direction by rotating the rotating member.

5. The apparatus according to claim 4 , wherein the at least one stiffness control unit is configured to control the stiffness of the output link in a range from the minimum stiffness to the maximum stiffness by rotating the rotating member clockwise or counterclockwise to an arbitrary direction between the first direction and the second direction.

6. The apparatus according to claim 1 , wherein
a plane of the rotating member perpendicular to the shaft is in a shape of ellipse having a major axis perpendicular to the longitudinal direction of the elongated hole, and
the least one stiffness control unit is configured to control the stiffness of the output link by rotating the rotating member in a continuous manner.

7. The apparatus according to claim 1 , wherein
a plane of the rotating member perpendicular to the shaft is in a shape of circle, and
the least one stiffness control unit is configured to control the stiffness of the output link by rotating the rotating member in a continuous manner.

8. The apparatus according to claim 1 , wherein
a plane of the rotating member perpendicular to the shaft is in a shape of polygon, and
the least one stiffness control unit is configured to control the stiffness of the output link by rotating the rotating member in a stepwise manner.

9. The apparatus according to claim 1 , wherein
the base member includes a main shaft to which the output link is coupled, and
the main shaft of the base member and the shaft of the least one stiffness control unit are configured to cause the output link and the rotating member to move in an integrated manner.

10. The apparatus according to claim 1 , wherein the output link includes at least one circular hole for accommodating the least one stiffness control unit on the inner side thereof.

11. The apparatus according to claim 1 , wherein
the base member includes a rail structure configured to guide the output link and the rotating member, and
the rail structure of the base member and the shaft of the least one stiffness control unit are configured to cause the output link and the rotating member to move in an integrated manner.

12. The apparatus according to claim 1 , wherein
a cross section of the second end of the shaft in a planar direction of the base member is in a shape of square, and
the rotating member is arranged in a manner that two outer surfaces of the second end of the shaft parallel to inner surfaces of the elongated hole parallel to the longitudinal direction thereof move along the inner surfaces of the elongated hole.

13. The apparatus according to claim 12 , wherein the shaft includes a roller on each corner of the second end.

14. The apparatus according to claim 12 , wherein
the elongated hole includes a guide structure configured to guide the shaft along the longitudinal direction thereof, and
the shaft includes a coupling structure configured to couple to the guide structure in a manner that the rotating member moves by guiding the shaft along the guide structure.

15. The apparatus according to claim 10 , wherein the output link includes the at least one circular hole at a position on a far side of the main shaft.

16. The apparatus according to claim 10 , wherein the output link includes the at least one circular hole at a position on a near side of the main shaft.

17. The apparatus according to claim 9 , wherein the at least one stiffness control unit includes a first stiffness control unit on a first side of the output link and a second stiffness control unit on a second side of the output link along the longitudinal direction of thereof.

18. A moving mechanism of a robot, the moving mechanism comprising:
a base member;
an output link configured to move along a plane parallel to a surface of the base member;
at least one stiffness control unit configured to control stiffness of the output link, the at least one stiffness control unit including
a shaft including a first end and a second end, the first end being rotatably coupled to the base member,
a rotating member including an elongated hole into which the second end of the shaft is movably inserted and rotatably arranged by the shaft at a position having contact with the output link outside or inside the output link, and
an elastic member between the second end of the shaft and at least one inner wall of the elongated hole in a longitudinal direction thereof; and
a contact unit configured to be coupled to the output link.

19. The moving mechanism according to claim 18 , wherein the contact unit includes at least one of an end effector of a robot arm, a robot hand, a robot foot, or a loading head.

20. An apparatus for controlling stiffness in a moving mechanism including a first member and a second member configured to make a relative movement with respect to the first member, the apparatus comprising:
a shaft including a first end and a second end, the first end being rotatably coupled to the first member;
a rotating member including an elongated hole into which the second end of the shaft is movably inserted, and rotatably arranged by the shaft at a position having contact with the second member on an outer side or of the second member; and
an elastic member between the second end of the shaft and at least one inner wall of the elongated hole in a longitudinal direction thereof, wherein
the apparatus is configured
to maximize the stiffness of the second member at a first position where the elongated hole is located in a first direct

Assignees

• Nat Cancer Ct

Inventors

• Kim Kwang Gi
• Jung Hyun Chul
• Cho Chang Nho

Classifications

• B25J19/068 Primary

  Actuating means with variable stiffness · CPC title

• B25J18/00

  Arms · CPC title

• B25J9/1641 Primary

  compensation for backlash, friction, compliance, elasticity in the joints · CPC title

• B25J19/00

  Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators (safety-devices in general F16P; protection against radiation in general G21F) · CPC title