Touch sensitive robotic gripper

• US 10,065,309 B2
• Filed: 02/10/2017
• Issued: 09/04/2018
• Est. Priority Date: 03/08/2012
• Status: Active Grant

• Current Assignee: Quality Manufacturing Inc. (Integrated Aerospace Manufacturing LLC)
• Original Assignee: Quality Manufacturing Inc. (Integrated Aerospace Manufacturing LLC)
• Inventors: Rose, Jeffrey A., Rose, James Adam, Rose, Stephen D., Cooper, Raymond, Sweda, Jeffrey John
• Primary Examiner(s): Amin, Bhavesh V
• Application Number:
  US15/430,042
• Publication Number:
  US 20170182657A1
• Time in Patent Office: 571 Days
• Field of Search: None
• CPC Class Codes: B25J 13/08 by means of sensing devices, e.g. viewing or touching devices
• CPC Class Codes: B25J 15/0028 with movable, e.g. pivoting gripping jaw surfaces
• CPC Class Codes: B25J 15/10 with three or more finger members B25J15/0009 takes precedence
• CPC Class Codes: B25J 9/1612 characterised by the hand, wrist, grip control
• CPC Class Codes: G01B 21/20 for measuring contours or curvatures, e.g. determining profile
• CPC Class Codes: G01L 1/16 using properties of piezoelectric devices
• CPC Class Codes: G05D 1/021 specially adapted to land vehicles
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y10S 901/01 Mobile robot
• CPC Class Codes: Y10S 901/27 Arm part
• CPC Class Codes: Y10S 901/28 Joint
• CPC Class Codes: Y10S 901/31 Gripping jaw
• CPC Class Codes: Y10S 901/46 Sensing device
• CPC Class Codes: Y10S 901/47 Optical

Abstract

A displacement measuring cell may be used to measure linear and/or angular displacement. The displacement measuring cell may include movable and stationary electrodes in a conductive fluid. Electrical property measurements may be used to determine how far the movable electrode has moved relative to the stationary electrode. The displacement measuring cell may include pistons and/or flexible walls. The displacement measuring cell may be used in a touch-sensitive robotic gripper. The touch-sensitive robotic gripper may include a plurality of displacement measuring cells mechanically in series and/or parallel. The touch-sensitive robotic gripper may be include a processor and/or memory configured to identify objects based on displacement measurements and/or other measurements. The processor may determine how to manipulate the object based on its identity.

Claims

1. A robotic gripping system comprising:

a robotic hand including,

a plurality of displacement measuring cells configured to measure a contour of a surface in contact with the robotic hand, and

a plurality of linear displacement sensors, each linear displacement sensor in series with a corresponding displacement measuring cell of the plurality of displacement measuring cells; and

a processor configured to;

compute a volume of an object based on measurements by the plurality of displacement measuring cells.

2. The robotic gripping system of claim 1, wherein the robotic hand further includes a plurality of fingers, wherein the plurality of displacement measuring cells include a plurality of rotational finger joints configured to measure angular displacement, and wherein the processor computes the volume by determining positions of the fingers when holding the object based on angular displacement measurements.

3. The robotic gripping system of claim 1, wherein the processor computes the volume by determining a detailed surface model based on measurements by the linear displacement sensors.

4. The robotic gripping system of claim 3, further comprising a plurality of springs, wherein each linear displacement sensor comprises a linear potentiometer, and wherein each spring is configured to return a corresponding linear potentiometer to an original position after the robotic hand releases the object.

5. The robotic gripping system of claim 3, wherein the processor is configured to determine locations of the plurality of linear displacement sensors based on measurements of angular displacement by a plurality of rotational finger joints.

6. The robotic gripping system of claim 1, wherein the processor is further configured to compare a model of the object computed from measurements by the plurality of linear displacement sensors with a model generated by a vision system.

7. The robotic gripping system of claim 6, wherein the vision system is selected from the group consisting of a two dimensional vision system and a three dimensional vision system.

8. The robotic gripping system of claim 6, wherein the processor is configured to compare the vision system generated model with a stored, computer aided design model.

9. The robotic gripping system of claim 6, wherein the model computed from the measurements by the plurality of linear displacement sensors comprises a computer aided design model.

10. The robotic gripping system of claim 6, wherein the model computed from the measurements by the plurality of linear displacement sensors comprises a real-time image.

11. The robotic gripping system of claim 6, wherein the processor is configured to identify surface asperities from the measurements by the plurality of linear displacements sensors;

and determine a pose of the object by comparing the identified surface asperities to the vision system model.

12. The robotic gripping system of claim 6, wherein the processor is configured to control the object based on the vision system model and an object pose identified based on the measurements by the plurality of linear displacement sensors.

13. The robotic gripping system of claim 1, wherein the plurality of linear displacement sensors comprise a conductive fluid.

14. The robotic gripping system of claim 1, wherein the robotic hand includes a plurality of fingers, and wherein the processor causes the fingers to index around the object to gather measurements for computing the volume.

15. The robotic gripping system of claim 1, further comprising another robotic hand, and wherein the processor causes the robotic hand and the other robotic hand to completely enclose the object to gather measurements for computing the volume.

16. The robotic gripping system of claim 1, wherein the processor is configured to generate a point cloud model of the object and store the point cloud model to a stored computer aided design model.

17. The robotic gripping system of claim 1, wherein the processor is configured to compute the volume of the object using spherical coordinates.

18. The robotic gripping system of claim 1, wherein the robotic hand includes a plurality of fingers, wherein the processor is configured to compute partial volumes based on measurements by individual fingers.

19. The robotic gripping system of claim 18, wherein the processor is configured to compute the total volume based on the partial volumes.

20. The robotic gripping system of claim 1, further comprising a vice, wherein the vice comprises a vice jaw including a plurality of linear displacement sensors.

21. The robotic gripping system of claim 20, wherein the robotic hand is configured to touch the plurality of linear displacement sensors of the vice jaw to calibrate positioning of the robotic hand relative to the vice.

22. The robotic gripping system of claim 21, wherein the robotic hand is configured to touch a plurality of orthogonal surfaces to calibrate positioning in a plurality of orthogonal directions.

23. The robotic gripping system of claim 21, wherein the plurality of linear displacement sensors of the vice jaw are located on an outside of the vice.

24. The robotic gripping system of claim 1, further comprising a wrist coupled to the robotic hand, wherein the wrist comprises one or more valves for controlling the flow of a fluid to the robotic hand.

25. The robotic gripping system of claim 1, wherein the processor is further configured to determine a pose of the object while the object is being gripped by the robotic hand.

26. The robotic gripping system of claim 25, wherein the processor is further configured to compute one or more rotations of the robotic hand and/or a robotic arm coupled to the robotic hand to correct an orientation of the object.

27. The robotic gripping system of claim 25, wherein the processor is further configured to control movement of the robotic hand based on the pose of another object in a pose measuring gripping apparatus.

28. A method for computing a volume of an object by contact with a robotic hand, the method comprising:

measuring a contour of the object in contact with a plurality of displacement measuring cells disposed on the robotic hand;

measuring pressure with a plurality of linear displacement sensors, each linear displacement sensor in series with a corresponding displacement measuring cell of the plurality of displacement measuring cells;

transmitting the pressure measurements to a processor; and

calculating, using the processor, the volume based on pressure measurements.

29. A non-transitory computer readable storage medium comprising program code configured to cause a processor to perform a method for computing a volume of an object by contact with a robotic hand, the method comprising:

measuring a contour of the object in contact with a plurality of displacement measuring cells disposed on the robotic hand;

measuring pressure with a plurality of linear displacement sensors, each linear displacement sensor in series with a corresponding displacement measuring cell of the plurality of displacement measuring cells;

transmitting the pressure measurements to a processor; and

calculating, using the processor, the volume based on pressure measurements.