Ball-balancing robot and drive assembly therefor

• US 10,189,342 B2
• Filed: 02/09/2016
• Issued: 01/29/2019
• Est. Priority Date: 02/09/2015
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Bewley, Thomas R., Friesen, Jeffrey M., Sihite, Eric, Yang, Daniel
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US15/549,520
• Publication Number:
  US 20180022197A1
• Time in Patent Office: 1,085 Days
• Field of Search: None
• 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: B60B 19/14 Ball-type wheels B60B19/06 takes precedence
• CPC Class Codes: B60B 33/08 Ball castors B60B33/0028 takes precedence
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 2007/003 with two or more motors driving a single wheel
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B62K 1/00 Unicycles

Abstract

A ball-balancing drive assembly includes a ball having a ball surface and a reference axis extending through a centroid of the ball. Three omniwheel assemblies, each having a motor with a motor axle and an omniwheel configured to rotate around the motor axle are mounted on a chassis configured for supporting the three omniwheel assemblies at radially symmetric spacings with the motor axles oriented at an angle relative to the reference axis and the omniwheels oriented in mutually-orthogonal planes. Each omniwheel frictionally contacts the ball surface to convert rotational motion of the motor axle to torque on the ball.

Claims

1. A ball-balancing drive assembly, comprising:

a ball having a ball surface and a reference axis extending through a centroid of the ball;

three omniwheel assemblies, each omniwheel assembly comprising a motor having a motor axle and an omniwheel configured to rotate around the motor axle;

a chassis configured for supporting the three omniwheel assemblies at radially symmetric spacings with the motor axles oriented at an angle relative to the reference axis and the omniwheels oriented in mutually-orthogonal planes, wherein each omniwheel frictionally contacts the ball surface to convert rotational motion of the motor axle to torque on the ball.

2. The ball-balancing drive assembly of claim 1, wherein the ball surface has an equator corresponding to a plane perpendicular to the reference axis that bisects the ball, wherein the omniwheels frictionally contact the ball surface within a mid-latitude range near the equator.

3. The ball-balancing drive assembly of claim 2, wherein the mid-latitude range comprises 20°

N to 30°

N of the equator.

4. The ball-balancing drive assembly of claim 1, wherein angle relative to the reference axis is within a range of 45°

to 80°

.

5. The ball-balancing drive assembly of claim 1, wherein the angle relative to the reference axis is within a range of 60°

to 70°

.

6. The ball-balancing drive assembly of claim 1, wherein the omniwheels are oriented mutually-orthogonally within a range of 35°

to 55°

.

7. The ball-balancing drive assembly of claim 1, wherein the omniwheels are oriented mutually-orthogonally within a range of 48°

to 52°

.

8. The ball-balancing drive assembly of claim 1, wherein the omniwheels are single row omniwheels.

9. The ball-balancing drive assembly of claim 1, wherein the omniwheels are double row omniwheels.

10. The ball-balancing drive assembly of claim 1, further comprising a frame extending from the chassis, the frame configured for supporting a power supply.

11. The ball-balancing drive assembly of claim 1, further comprising a controller for selectively and independently activating each omniwheel assembly.

12. A ball-balancing robot, comprising:

a ball having a ball surface and a reference axis extending through a centroid of the ball;

three omniwheel assemblies, each omniwheel assembly comprising a motor having a motor axle and an omniwheel configured to rotate around the motor axle;

a chassis configured for supporting the three omniwheel assemblies at 120°

spacings with the motor axles oriented at an angle a relative to the reference axis and the omniwheels rotated at an angle β

to define mutually-orthogonal planes, wherein each omniwheel frictionally contacts the ball surface to convert rotational motion of the motor axle to torque on the ball;

a frame extending upward from the chassis;

a control assembly disposed on the frame, the control assembly comprising an electronic controller for selectively and independently activating the omniwheel assemblies; and

a power supply for powering the motors and the control assembly.

13. The ball-balancing robot of claim 12, wherein the ball surface has an equator corresponding to a plane perpendicular to the reference axis that bisects the ball, wherein the omniwheels frictionally contact the ball surface within a mid-latitude range near the equator.

14. The ball-balancing robot of claim 13, wherein the mid-latitude range comprises 20°

N to 30°

N of the equator.

15. The ball-balancing robot of claim 12, wherein angle α

is within a range of 45°

to 80°

.

16. The ball-balancing robot of claim 12, wherein the angle β

is within a range of 35°

to 55°

.

17. The ball-balancing robot of claim 12, wherein the angle α

and the angle β

are selected as an angle pair from the pairs consisting of

18. The ball-balancing robot of claim 12, wherein the omniwheels are single row omniwheels.

19. The ball-balancing robot of claim 12, wherein the omniwheels are double row omniwheels.

20. The ball-balancing robot of claim 12, further comprising an outer skin configured for enclosing at least of portion of the frame, control assembly and power supply.