Robotic vehicle system

• US 8,260,459 B2
• Filed: 05/08/2009
• Issued: 09/04/2012
• Est. Priority Date: 05/08/2008
• Status: Active Grant

• Current Assignee: Regents of the University Minnesota, Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Herbert, Sammuel D., Papanikolopoulos, Nikolaos P.
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): LANG, MICHAEL DEAN
• Application Number:
  US12/463,067
• Publication Number:
  US 20100076598A1
• Time in Patent Office: 1,215 Days
• Field of Search: 700/245
• US Class Current: 700/245
• CPC Class Codes: B62D 57/02 with ground-engaging propulsion means, e.g. walking members

Abstract

Robotic vehicle systems and methods regarding such systems, such as, e.g., methods of movement for such robotic vehicle systems (e.g., movement across varying terrain including steps).

Claims

1. A robotic vehicle system comprising:

a frame; and

at least four wheels, wherein a first pair of the at least four wheels are rotatably coupled on opposite sides of the frame along a first axis and a second pair of the at least four wheels are rotatably coupled on opposite sides of the frame along a second axis, and further wherein each wheel of the at least four wheels comprises;

a hub portion, and

at least three surface-engaging lobe portions spaced equidistantly about the hub portion, wherein at least each lobe portion comprises a plurality of layers coupled together, wherein each of the at least three lobe portions terminates in a continuous curvature, and further wherein the hub portion is rotatably coupled to the frame to allow movement of the hub portion and the at least three lobe portions together about one of the first and second axes.

2. The robotic vehicle system of claim 1, wherein each lobe portion of the at least three lobe portions is symmetric about a radial axis extending orthogonally from one of the first and second axes.

3. The robotic vehicle system of claim 1, wherein the system further comprises:

at least four actuators, wherein each actuator is coupled to a corresponding hub portion of one of the at least four wheels and coupled to the frame to provide movement of the corresponding hub portion about one of the first and second axis; and

a control system electrically coupled to the at least four actuators to individually control each actuator.

4. The robotic vehicle system of claim 1, wherein the frame is compliant such that the frame is in a first position when in a normal state, and at least a portion of the frame may be deflected from the first position when in a stressed state.

5. The robotic vehicle system of claim 1, wherein the curvature of each of the at least three lobe portions is the same.

7. The robotic vehicle system of claim 1, wherein the hub portion and the at least three lobe portions of each wheel comprise a plurality of layers coupled together with one or more of the plurality of layers comprising at least a part of the hub portion and a part of each lobe portion of the wheel.

8. The robotic vehicle system of claim 1, wherein the plurality of layers comprises alternating support layers and compliant layers.

9. The robotic vehicle system of claim 8, wherein the support layers comprise a polymer.

10. The robotic vehicle system of claim 8, wherein the compliant layers comprise a polymer.

6. The robotic vehicle system of 1, wherein the at least three lobe portions lie in a plane orthogonal to one of the first and second axis when in a normal state, and further wherein at least a part of at least one of the at least three lobe portions is deflected from the plane when in a stressed state.

11. A method for controlling a robotic vehicle system to climb one or more steps, wherein each step of the one or more steps comprises a landing, the method comprising:

providing a robotic vehicle system, the robotic vehicle system comprising;

a frame, and

at least four wheels, wherein a first pair of the at least four wheels are rotatably coupled on opposite sides of the frame along a first axis and a second pair of the at least four wheels are rotatably coupled on opposite sides of the frame along a second axis, and further wherein each wheel of the at least four wheels comprises;

a hub portion, and

at least three surface-engaging lobe portions spaced equidistantly about the hub portion, wherein each of the at least three lobe portions terminates in a continuous curvature, wherein the hub portion is rotatably coupled to the frame to allow movement of the hub portion and the at least three lobe portions together about one of the first and second axes;

locating the robotic vehicle system proximate the one or more steps, wherein a first lobe portion of the at least three lobe portions of the first pair of wheels is in contact with a surface proximate a first step of the one or more steps;

rotating the first pair of wheels to contact the landing of the first step with a second lobe portion of the at least three lobe portions of the first pair of wheels;

further rotating the first pair of wheels to lift the first lobe portion of the at least three lobe portions of the first pair of wheels off of the surface; and

rotating the second pair of wheels to assist in moving the robotic vehicle system up the first step.

12. The method of claim 11, wherein the method further comprises:

rotating the first pair of wheels to contact the landing of a second step with a third lobe portion of the at least three lobe portions of the first pair of wheels; and

further rotating the first pair of wheels to lift the second lobe portion of the at least three lobe portions of the first pair of wheels off of the landing of the first step.

13. The method of claim 11, wherein the at least each lobe portion of each wheel of the at least four wheels of the robotic vehicle system comprises a plurality of layers coupled together.

14. The method of claim 11, wherein the first pair of wheels are rotated in phase with each other, and the second pair of wheels are rotated in phase with each other, wherein the first pair of wheels are out of phase with the second pair of wheels.

15. The method of claim 11, the method further comprising:

monitoring the rotation of each wheel of the at least four wheels individually; and

adjusting the rotation of at least one wheel of the at least four wheels in response to the individual rotations of at least one wheel of the at least four wheels.

16. The method of claim 11, the method further comprising adjusting the phase between the first pair of wheels and the second pair of wheels to match a period between adjacent steps of the one or more steps.

17. A method for controlling a robotic vehicle system to traverse a surface, the method comprising:

providing a robotic vehicle system, the robotic vehicle system comprising;

a frame, and

at least four wheels, wherein a first pair of the at least four wheels are rotatably coupled on opposite sides of the frame along a first axis and a second pair of the at least four wheels are rotatably coupled on opposite sides of the frame along a second axis, and further wherein each wheel of the at least four wheels comprises;

a hub portion, and

at least three surface-engaging lobe portions spaced equidistantly about the hub portion, wherein each of the at least three lobe portions terminates in a continuous curvature, wherein the hub portion is rotatably coupled to the frame to allow movement of the hub portion and the at least three lobe portions together about one of the first and second axes;

locating the robotic vehicle system upon the surface; and

rotating the at least four wheels to move across the surface.

18. The method of claim 17, wherein rotating the at least four wheels comprises:

rotating a first wheel of the first pair of wheels in phase with a first wheel of the second pair of wheels, wherein the first wheel of the first pair of wheels and the first wheel of the second pair of wheels are rotatably coupled to the frame on opposite sides; and

rotating a second wheel of the first pair of wheels in phase with a second wheel of the second pair of wheels, wherein the second wheel of the first pair of wheels and the second wheel of the second pair of wheels are rotatably coupled to the frame on opposite sides, wherein the first wheel of the first pair of wheels is out of phase with the second wheel of the first pair of wheels.

19. The method of claim 17, wherein rotating the at least four wheels comprises rotating a first wheel of the first pair of wheels and a first wheel of the second pair of wheels in phase with each other, wherein the first wheel of the first pair of wheels and the first wheel of the second pair of wheels are rotatably coupled to the frame on the same side.

20. The method of claim 17, the method further comprising:

monitoring the rotation of each wheel of the at least four wheels individually; and

adjusting the rotation of at least one wheel of the at least four wheels individually in response to the monitored individual rotation of at least one wheel of the at least four wheels.