RiSE: First Steps up the Wall

1. RiSE: First Steps up the Wall Center for the Foundation of Robotics Southwest Research Institute (SwRI), March 3-12, 2005 Clark Haynes and Sarjoun Skaff March 22, 2005 RiSE: First Steps up the Wall

2. RiSE: First Steps up the Wall

3. Wall Climbing Challenges Minimally Invasive Multiple Surfaces Dynamic Climbing Low Power Discreet RiSE: First Steps up the Wall

4. Biologically Inspired Answer • Collection of feet • Sticky for smooth surfaces • Clawed for rough surfaces • Six leg • Actuated motion • Passive compliance RiSE: First Steps up the Wall

5. RiSE • Robot in Scansorial Environments • First prototype to climb hard and • soft surfaces • Develop intuition to improve • performance Dactyl on carpet Sticky foot on Plexiglass RiSE: First Steps up the Wall

6. Outline • System Description Field Trip Climbing Surfaces Behavior Generation RiSE: First Steps up the Wall

7. Mechanical Platform RiSE: First Steps up the Wall

8. Mechanical Platform RiSE: First Steps up the Wall

9. Climbing Carpet at 90° Feet Type Dactyl Gait Type Tripod Challenge Difficult Detachment RiSE: First Steps up the Wall

10. Climbing Cork at 90° Feet Type Spiny Gait Type Tripod • Challenges • Fragile material  Careful attachment • Failed attachment  Immediate fall • Attachmentsensitive to spine sharpness RiSE: First Steps up the Wall

11. Climbing PlexiGlass at 55° Feet Type Lamellarized Polyurethane Gait Type Tetrapod • Challenges • Large Feet  High C.O.G. • Foot contact area depends on weight distribution • Vibrations limits foot contact area RiSE: First Steps up the Wall

12. Walking Feet Type Rubber Gait Type Tripod • Challenges • Inadequate passive compliance • Small gear ratio  Low speed RiSE: First Steps up the Wall

13. Gait Design 2π 0 β = FKin(Θ) 0 1 • 1st DOF: 4-bar kinematics, “Beta Curve” • 2nd DOF: Wing joint • Beta x Wing  2D Manifold RiSE: First Steps up the Wall

14. Geometric Considerations Plexiglass Walking • Beta Curve chosen to perform both running and climbing • Gaits are piecewise linear trajectories upon 2D Manifold • 4 components to a generic climbing gait: • “Attachment”, “Stance”, “Detachment”, “Flight” RiSE: First Steps up the Wall

15. Trajectory Variations Plexiglass Carpet Cork • Surface properties dictate climbing trajectories • Pull-in forces, attachment, detachment vary RiSE: First Steps up the Wall

16. Fore-Aft Differentiation Carpet Leg 1 Carpet Leg 3 Push-Pull relationship between back and front legs helps to prevent pitchback of robot RiSE: First Steps up the Wall

17. Forward vs. Backward Gaits Carpet Forward Carpet Backward • Running gait in reverse doesn’t work! • Attachment requires pull-in, detachment needs straight • exit from surface RiSE: First Steps up the Wall

18. Leg Phasing and Duty Factors Tripod Tetrapod Pentapod Rippled Tripod RiSE: First Steps up the Wall

19. Carpet Mobility Challenge: • Maneuver robot through obstacle course on carpeted surface • Turning with claws attached to wall • Forward vs. Backward gaits • Tripod vs. Pentapod for speed, stability RiSE: First Steps up the Wall

20. Tripod Turning Tripod 1 Tripod 2 50% 50% RiSE: First Steps up the Wall

21. Tripod Turning Tripod 1a Tripod 1b Tripod 2 25% 25% 50% RiSE: First Steps up the Wall

22. Ripple/Tetrapod Turning Set 1 Set 2 Set 3 33% 33% 33% RiSE: First Steps up the Wall

23. Transitions - Related Gaits Forward Tripod Backward Tripod RiSE: First Steps up the Wall

24. Transitions – Unrelated Gaits Tripod Pentapod RiSE: First Steps up the Wall

25. SwRI Test Facility RiSE: First Steps up the Wall

26. Carpet Mobility RiSE: First Steps up the Wall

27. Hybrid Foot Configuration RiSE: First Steps up the Wall

28. Tree Climbing RiSE: First Steps up the Wall

29. Clinging to Surfaces RiSE: First Steps up the Wall

30. On-site Foot Development RiSE: First Steps up the Wall

31. Brick RiSE: First Steps up the Wall

32. Walking RiSE: First Steps up the Wall

33. Lessons Learned • PlexiGlass • Adhesion deteriorates with dirt •  Climbing 0.5m is different from climbing 3m • Foot morphology • Large feet  More adhesion • Small Feet  C.O.G closer to surface  Steeper climbs • Cork • Fragile surfaces  Smooth attachment • Re-Attach to avoid fall  Detect attachment failure • Carpet • - Difficult detachment  Detect detachment failure, Microspines RiSE: First Steps up the Wall

34. Looking Ahead • - Drop the gears • Actuate the tail • Climb faster • Climb outdoor surfaces • Multi-purpose feet • Horizontal ↔ Vertical • Add Feedback RiSE: First Steps up the Wall

35. Credits Lewis & Clark K. Autumn M. Buehler M. Cutkosky R. FearingR. J. Full D. E. Koditschek A. A. RizziClark HaynesSarjoun SkaffUluç Saranli Boston Dynamics Stanford UC Berkeley UC Berkeley U Penn Carnegie Mellon RiSE: First Steps up the Wall

36. RiSE: First Steps up the Wall

37. Surface Loads FT FN L MT MN AT AN Mg Mg TN D Normal Loading Tangential Loading Assume Assume equal weight distribution Tangential Force Normal Force • Tangential Force Max • Fully Attached • Partially Attached • Normal Force Max • Fully Attached • Partially Attached RiSE: First Steps up the Wall