Wind-up gripper for a robotic device

Patent metadata

Field	Value
Publication number	US-10011019-B1
Application number	US-201615146688-A
Country	US
Kind code	B1
Filing date	May 4, 2016
Priority date	May 4, 2016
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A robotic gripping device is provided. The robotic gripping device includes two opposable fingers and an actuator having a motor and a shaft, wherein the shaft is coupled to a first finger. The robotic gripping device also includes a torsion spring surrounding the actuator, the torsion spring having first and second ends, wherein the first end is coupled to the motor of the actuator and the second end is coupled to a second finger. Further, the actuator is configured to rotate the shaft relative to the motor by a first amount to move the two opposable fingers toward each other to contact the object. The actuator is also configured to further rotate the shaft relative to the motor to wind up the torsion spring when the two opposable fingers are both in contact with the object and the object prevents the fingers from further movement toward each other.

First claim

The invention claimed is:

1. A robotic gripping device comprising:
two opposable fingers configured to move toward each other to grasp an object;
an actuator having a motor and a shaft, wherein the shaft is coupled to a first finger of the opposable fingers; and
a torsion spring surrounding the actuator, the torsion spring having a first end and a second end, wherein the first end is coupled to the motor of the actuator and the second end is coupled to a second finger of the two opposable fingers;
wherein the actuator is configured to:
rotate the shaft relative to the motor by a first amount to move the two opposable fingers toward each other to contact the object; and
when the two opposable fingers are both in contact with the object and the object prevents the fingers from further movement toward each other, further rotate the shaft relative to the motor to wind up the torsion spring.

2. The robotic gripping device of claim 1 , wherein the two opposable fingers are hyper-underactuated, such that the actuator is configured to move the first finger of the two fingers when the second finger of the two fingers is prevented from movement.

3. The robotic gripping device of claim 1 , wherein the two opposable fingers are configured to rotate about two respective axes to grasp the object in a pinching grasp.

4. The robotic gripping device of claim 1 , wherein the two opposable fingers are configured to move translationally to grasp the object.

5. The robotic gripping device of claim 1 , further comprising a base section, wherein the actuator is rotatably coupled to the base section via two rotary bearings.

6. The robotic gripping device of claim 1 , further comprising:
an actuator encoder configured to detect a rotation amount of the shaft relative to the motor;
a finger encoder configured to detect a movement amount of the opposable fingers; and
a control system, wherein the control system is configured to determine an amount of torque applied to the two opposing fingers in a gripping direction based on the actuator encoder, the finger encoder, and a characteristic of the torsion spring.

7. The robotic gripping device of claim 6 , wherein the control system is further configured to determine the amount of torque applied to the two opposing fingers in the gripping direction based on a difference between the rotation amount detected by the actuator encoder and the movement amount detected by the finger encoder.

8. The robotic gripping device of claim 6 , wherein the torsion spring has a spring constant, and wherein the control system is further configured to determine the amount of torque applied to the two opposing fingers in the gripping direction based on the spring constant.

9. A robotic gripping device comprising:
two opposable fingers configured to move toward each other to grasp an object;
an actuator having a motor and a shaft, wherein the motor is coupled to a first finger of the opposable fingers; and
a torsion spring surrounding the actuator, the torsion spring having a first end and a second end, wherein the first end is coupled to the shaft of the actuator and the second end is coupled to a second finger of the two opposable fingers;
wherein the actuator is configured to:
rotate the shaft relative to the motor by a first amount to move the two opposable fingers toward each other to contact the object; and
when the two opposable fingers are both in contact with the object and the object prevents the fingers from further movement toward each other, further rotate the shaft relative to the motor to wind up the torsion spring.

10. The robotic gripping device of claim 9 , wherein the two opposable fingers are hyper-underactuated, such that the actuator is configured to move the first finger of the two fingers when the second finger of the two fingers is prevented from movement.

11. The robotic gripping device of claim 9 , wherein the two opposable fingers are configured to rotate about two respective axes to grasp the object in a pinching grasp.

12. The robotic gripping device of claim 9 , wherein the two opposable fingers are configured to move translationally to grasp the object.

13. The robotic gripping device of claim 9 , further comprising a base section, wherein the actuator is rotatably coupled to the base section via two rotary bearings.

14. The robotic gripping device of claim 9 , further comprising:
an actuator encoder configured to detect a rotation amount of the shaft relative to the motor;
a finger encoder configured to detect a movement amount of the opposable fingers; and
a control system, wherein the control system is configured to determine an amount of torque applied to the two opposing fingers in a gripping direction based on the actuator encoder, the finger encoder, and a characteristic of the torsion spring.

15. The robotic gripping device of claim 14 , wherein the control system is further configured to determine the amount of torque applied to the two opposing fingers in the gripping direction based on a difference between the rotation amount detected by the actuator encoder and the movement amount detected by the finger encoder.

16. The robotic gripping device of claim 14 , wherein the torsion spring has a spring constant, and wherein the control system is further configured to determine the amount of torque applied to the two opposing fingers in the gripping direction based on the spring constant.

17. A method comprising:
identifying an object for a robotic gripping device to grasp, wherein the robotic gripping device comprises two opposable fingers, an actuator, and a torsion spring, wherein:
(i) the two opposable fingers are configured to move toward each other to grasp the object;
(ii) the actuator has a motor and a shaft, wherein the shaft is coupled to a first finger of the two opposable fingers; and
(iii) the torsion spring surrounds the actuator and has first and second ends, wherein the first end of the torsion spring is coupled to the motor of the actuator and the second end of the torsion spring is coupled to a second finger of the two opposable fingers;
rotating the shaft of the actuator relative to the motor by a first amount to move the two opposable fingers toward each other to contact the object; and
when the two opposable fingers are both in contact with the object and the object prevents the fingers from further movement toward each other, further rotating the shaft of the actuator relative to the motor to wind up the torsion spring.

18. The method of claim 17 , wherein the two opposable fingers are hyper-underactuated, such that the actuator is configured to move the first finger of the two fingers when the second finger of the two fingers is prevented from movement.

19. The method of claim 17 , wherein the robotic gripping device further comprises:
an actuator encoder configured to detect a rotation amount of the shaft relative to the motor;
a finger encoder configured to detect a movement amount of the opposable fingers; and
a control system, wherein the method further comprises:
determining, by the control system, an amount of torque applied to the two opposing fingers in a gripping direction based on the actuator encoder, the finger encoder, and a characteristic of the torsion spring.

20. The method of claim 19 , wherein determining, by the control system, the amount of torque applied to the fingers comprises:
determining a difference between the rotation amount detected by the actuator encoder and the movement amount detected by the

Assignees

• X Dev Llc

Inventors

• Strauss Marc

Classifications

• B25J15/08

  having finger members (B25J15/02, B25J15/04 take precedence) · CPC title

• B25J15/0028 Primary

  with movable, e.g. pivoting gripping jaw surfaces · CPC title

• B25J15/022 Primary

  actuated by articulated links · CPC title