Highly mobile robots that run and jump

• US 20050133280A1
• Filed: 05/13/2004
• Published: 06/23/2005
• Est. Priority Date: 06/04/2001
• Status: Active Grant

• Current Assignee: Andrew D. Horchler, Bram Lambrecht, Jeremy M. Morrey, Roger D. Quinn
• Original Assignee: Andrew D. Horchler, Bram Lambrecht, Jeremy M. Morrey, Roger D. Quinn
• Inventors: Horchler, Andrew D., Quinn, Roger D., Lambrecht, Bram, Morrey, Jeremy M.
• Granted Patent: US 7,249,640 B2
• Time in Patent Office: Days
• US Class Current: 180/8.100
• CPC Class Codes: B62D 57/022 consisting of members having both rotational and walking movements

Abstract

The present invention relates to novel, highly mobile small robots called “Mini-Whegs” that can run and jump. They are derived from our larger Whegs series of robots, which benefit from abstracted cockroach locomotion principles. Part of their success is derived from the three spoked appendages, called “whegs”, which combine the speed and simplicity of wheels with the climbing mobility of legs. To be more compact than the larger Whegs vehicles, Mini-Whegs uses four whegs in an alternating diagonal gait. These 9 cm long robots can run at sustained speeds of over 10 body lengths per second and climb obstacles that are taller than their leg length. They can run forward and backward, on either side. Their robust construction allows them to tumble down a flight of stairs with no damage and carry a payload equal to twice their weight. A jumping mechanism enables Mini-Whegs to surmount much larger obstacles such as stair steps.

Claims

1. A vehicle, comprising:

a chassis;

front and rear axles, each axle having two multi-spoke driving appendages;

the multi-spoke driving appendages attached to the chassis to permit rotation of the driving appendages to propel the chassis;

an actuation device;

a drive train linking the actuation device to the multi-spoke driving appendages; and

wherein the front axle and the rear axle are connected to the actuation device to maintain a nominal phase offset between the front and rear axles to achieve an alternating diagonal gait.

2. The vehicle of claim 1, wherein the actuation device is a single drive motor capable of driving each of the driving appendages.

3. The vehicle of claim 1, further comprising a jumping mechanism.

4. The vehicle of claim 1, further comprising an onboard radio control system.

5. The vehicle of claim 1, wherein the multi-spoke driving appendages are 3 spoke whegs.

6. The vehicle of claim 5, wherein the multi-spoke driving appendages further include a foot comprising an arc segment that generally follows the circumference of the driving appendage.

7. The vehicle of claim 6, wherein the length of the foot is selected to provide a compromise of a smooth ride verses climbing performance.

8. The vehicle of claim 6, wherein the foot length comprises an arc segment between 10 and 40 degrees.

9. The vehicle of claim 5, wherein the spokes on at least one of the 3 spoke driving appendages are splayed outward.

10. The vehicle of claim 3, wherein the actuation device includes a single drive motor connected to the front axle and the rear axle by two sets of chains and sprockets;

and is further connected via a third chain to a jump transmission that outputs a slow, high torque motion to preload the jumping mechanism.

11. The vehicle of claim 1, wherein the multi-spoke driving appendages have spokes that are made from a flexible material to provide compliance.

12. The vehicle of claim 1, wherein the spokes are driven by the axles through a flexible coupling system to provide compliance.

13. The vehicle of claim 1, wherein flexible materials are used in the multi-spoke driving appendages and/or the front axle components provide torsional compliance for automatic gait adaptation.

14. The vehicle of claim 1, wherein the front axle and the rear axle are connected to one drive motor via non-slipping drive train to maintain the nominal phase offset between the front and rear axles to achieve an alternating diagonal gait.

15. The vehicle of claim 3, wherein the jumping mechanism is spring-activated.

16. The vehicle of claim 3, wherein the jumping mechanism is self-resetting.

17. The vehicle of claim 3, wherein the jumping mechanism comprises a four-bar linkage.

18. The vehicle of claim 17, wherein the jumping mechanism further comprises a sharp tipped foot.

19. The vehicle of claim 3, wherein the jumping mechanism comprises a spring.

20. The vehicle of claim 19, wherein the spring is preloaded.

21. The vehicle of claim 3, wherein the jumping mechanism further comprises a quick-release mechanism.

22. The vehicle of claim 3, wherein the jumping mechanism comprises:

a secondary transmission; and

a four-bar linkage;

wherein the four-bar linkage is attached to the frame via two pivoting axles.

23. The vehicle of claim 22, wherein the jumping mechanism further comprises a spiked lower bar to propel the chassis forward and upward.

24. The vehicle of claim 22, wherein the jumping mechanism folds into a compact position between jumps.

25. The vehicle of claim 3, wherein the jumping mechanism further comprises a slip-gear mechanism wherein the slip-gear mechanism is adapted such that:

a gear with a portion with several teeth removed or ‘

slip-gear’

is driven by a motor with or without a transmission;

the slip-gear engages an unmodified gear that is attached to one of the rotating cross bars in a four-bar linkage of the jumping mechanism;

the motor turns the slip-gear thereby rotating the four bar linkage and storing energy in a spring;

the slip-gear rotates to reach the portion with several teeth removed so that it no longer engages the unmodified gear attached to the four-bar linkage; and

with the motion of the four-bar linkage no longer constrained, the spring releases its energy and causes the four-bar linkage to return to its open position.

26. The vehicle of claim 21, wherein the quick-release mechanism includes a slip-gear mechanism adapted such that after jumping, the slip-gear reengages a driven gear and repeats the jumping process.

27. The vehicle of claim 21, wherein the jumping mechanism is adapted such that the jumping actuation and control is independent of drive actuation.

28. The vehicle of claim 3, wherein the jumping mechanism is adapted such that the jumping actuation and control is independent of drive actuation.

29. The vehicle of claim 3, wherein the jumping mechanism comprises a separate jump motor.

30. The vehicle of claim 1, further including a steering system.

31. The vehicle of claim 30, wherein the drive train includes a torsionally compliant device.

32. The vehicle of claim 31, wherein the torsionally compliant device includes a spring.

33. The vehicle of claim 32, wherein the spring has a preload.

34. The vehicle of claim 30, wherein said multi-spoke driving appendages have at least three compliant spokes.

35. A vehicle comprising:

a chassis;

a motor secured to the chassis; and

a drive system secured to the chassis and connected to the motor;

a plurality of multi-spoke driving appendages; and

a compliant device to allow adaptive gait changes between individual driving appendages.

36. The vehicle of claim 35 further comprising, a jumping mechanism.

37. The vehicle of claim 36, wherein the drive system comprises:

a drive member that provides a source of rotational power/torque;

a pair of pretensioned torsionally compliant devices, each coupled to receive rotational power/torque via the drive member; and

a pair of the multi-spoke driving appendages, each coupled to a respective one of the torsionally compliant devices to rotate in response to the rotational power/torque provided by the respective torsionally compliant device;

wherein the torsionally compliant devices allow a phase angle change between the pair of driving appendages in response to a force or torque applied to at least one of the driving appendages.

38. The vehicle of claim 35, wherein the multi-spoke driving appendages are compliant

39. The vehicle of claim 35, comprising front and rear axles wherein the front and rear axles are phased to employ a diagonal gait.

40. The vehicle of claim 39, wherein the diagonal gait is such that when a spoke of one driving appendage contacts the terrain, a spoke of the driving appendage located on the opposite axle and on the opposite side of the vehicle contacts the terrain in generally the same manner.

41. The vehicle of claim 39, wherein the multi-spoke driving appendages may be perturbed passively from a diagonal gait on uneven terrain and return to a diagonal gait on even terrain.

42. A robot adapted to run and jump, comprising:

a robot chassis designed to accept the mounting of any of;

a drive train, a steering system, a power supply, and/or an onboard radio control system;

two axles movably mounted to the chassis, each axle having two whegs (three spoke appendages); and

a drive motor and transmission attached to the chassis to drive the two whegs on each axle and to simultaneously power a jumping mechanism.

43. The robot of claim 42, wherein:

each of the whegs are driven by the drive motor via two sets of chains and sprockets connected to the two axles; and

a third chain is connected to a transmission that outputs a slow, high torque motion to wind a spring-activated jumping mechanism.

44. The robot of claim 43 wherein:

each wheg has a foot that consists of an arc segment that follows the circumference of the wheg.