Roller assembly for autonomous mobile robots

• US 9,073,501 B2
• Filed: 09/05/2014
• Issued: 07/07/2015
• Est. Priority Date: 09/05/2013
• Status: Active Grant

• Current Assignee: Harvest Automation, Inc.
• Original Assignee: Harvest Automation, Inc.
• Inventors: Allen, Seth, Bush, Michael
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): WONG, YUEN H
• Application Number:
  US14/478,736
• Publication Number:
  US 20150066281A1
• Time in Patent Office: 305 Days
• Field of Search: 701/23
• US Class Current: 1/1
• CPC Class Codes: B25J 19/0091 Shock absorbers in general F16F
• CPC Class Codes: B25J 19/06 Safety devices
• CPC Class Codes: B25J 5/00 Manipulators mounted on wheels or on carriages B25J1/00 takes precedence; programme-controlled manipulators B25J9/00 ; vehicle aspects B60, B62, e.g. remote-controlled steering for motor vehicles B62D1/24; control of position of vehicles G05D1/00
• CPC Class Codes: B25J 5/007 mounted on wheels
• CPC Class Codes: B60R 19/16 having deflecting members, e.g. rollers, balls
• CPC Class Codes: B60R 19/22 containing mainly cellular material, e.g. solid foam
• CPC Class Codes: Y10S 901/01 Mobile robot
• CPC Class Codes: Y10S 901/49 Protective device

Abstract

A roller assembly provides collision protection and stability to a mobile robot. The roller assembly includes a shaft forming an axis about which the roller assembly can rotate. The shaft has opposite ends configured to be supported by bearings in the robot. The roller assembly also includes an impact absorbing layer coaxially covering the shaft. It further includes a shell coaxially covering the impact absorbing layer having a lower coefficient of friction than the impact absorbing layer for providing low sliding friction.

Claims

1. A roller assembly for providing collision protection and stability to a mobile robot, comprising:

a shaft forming an axis about which the roller assembly can rotate, said shaft having opposite ends configured to be supported by bearings in the mobile robot;

an impact absorbing layer coaxially covering the shaft; and

a shell coaxially covering the impact absorbing layer having a lower coefficient of friction than the impact absorbing layer for providing low sliding friction.

2. The roller assembly of claim 1, wherein the shaft comprises a center portion between the opposite ends, and wherein the impact absorbing layer and the shell coaxially cover the center portion of the shaft.

3. The roller assembly of claim 1, wherein the outer shell is tapered at opposite ends thereof to enable the mobile robot to more easily turn in place.

4. The roller assembly of claim 1, wherein the shaft includes a plurality of features along the length thereof to engage and securely retain the impact absorbing layer.

5. The roller assembly of claim 1, wherein the impact absorbing layer is molded or cast on the shaft.

6. The roller assembly of claim 1, wherein the impact absorbing layer includes one or more open volumes extending along the length thereof for enabling deformation thereof and reducing stiffness.

7. The roller assembly of claim 1, wherein the impact absorbing layer comprises a foamed material having built-in voids.

8. The roller assembly of claim 1, wherein the impact absorbing layer comprises an elastomer layer.

9. The roller assembly of claim 1, wherein the impact absorbing layer comprises an a wire wound spring or a gas bladder spring.

10. The roller assembly of claim 1, wherein the shaft comprises metal.

11. The roller assembly of claim 1, wherein the outer shell comprises a plastic material.

12. The roller assembly of claim 1, wherein the outer shell comprises a material providing a slippery outer surface.

13. The roller assembly of claim 1, wherein the outer shell comprises a material for reducing stiffness of the roller assembly.

14. The roller assembly of claim 1, wherein the outer shell comprises a material for increasing stiffness of the roller assembly.

15. A mobile robot, comprising:

a chassis;

a drive subsystem for maneuvering the chassis;

a controller on the chassis for controlling the drive subsystem; and

a roller assembly for providing collision protection and stability to the mobile robot, the roller assembly comprising;

a shaft forming an axis about which the roller assembly can rotate, said shaft having opposite ends supported by bearings on the chassis;

an impact absorbing layer coaxially covering the shaft; and

a shell coaxially covering the impact absorbing layer having a lower coefficient of friction than the impact absorbing layer for providing low sliding friction.

16. The mobile robot of claim 15, further comprising a gripper assembly on the chassis for grabbing and holding an object to be transported by the mobile robot, wherein the roller assembly is positioned outside of a work envelope of the gripper assembly.

17. The mobile robot of claim 15, wherein the shaft of the roller assembly comprises a center portion between the opposite ends, and wherein the impact absorbing layer and the shell coaxially cover the center portion of the shaft.

18. The mobile robot of claim 15, wherein the outer shell of the roller assembly is tapered at opposite ends thereof to enable the mobile robot to more easily turn in place.

19. The mobile robot of claim 15, wherein the shaft of the roller assembly includes a plurality of features along the length thereof to engage and securely retain the impact absorbing layer.

20. The mobile robot of claim 15, wherein the impact absorbing layer of the roller assembly is molded or cast on the shaft.

21. The mobile robot of claim 15, wherein the impact absorbing layer of the roller assembly includes one or more open volumes extending along the length thereof for enabling deformation thereof and reducing stiffness.

22. The mobile robot of claim 15, wherein the impact absorbing layer of the roller assembly comprises a foamed material having built-in voids.

23. The mobile robot of claim 15, wherein the impact absorbing layer of the roller assembly comprises an elastomer layer.

24. The mobile robot of claim 15, wherein the impact absorbing layer of the roller assembly comprises an a wire wound spring or a gas bladder spring.

25. The mobile robot of claim 15, wherein the shaft of the roller assembly comprises metal.

26. The mobile robot of claim 15, wherein the outer shell of the roller assembly comprises a plastic material.

27. The mobile robot of claim 15, wherein the outer shell of the roller assembly comprises a material providing a slippery outer surface.

28. The mobile robot of claim 15, wherein the outer shell of the roller assembly comprises a material for reducing stiffness of the roller assembly.

29. The mobile robot of claim 15, wherein the outer shell comprises a material for increasing stiffness of the roller assembly.