RiSE: First Steps up the Wall - PowerPoint PPT Presentation

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

Minimally

Invasive

Multiple Surfaces

Dynamic Climbing

Low Power

Discreet

RiSE: First Steps up the Wall

• Collection of feet
• Sticky for smooth surfaces
• Clawed for rough surfaces

• Six leg
• Actuated motion
• Passive compliance

RiSE: First Steps up the Wall

• 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

• System Description

Field Trip

Climbing Surfaces

Behavior Generation

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

Feet Type

Dactyl

Gait Type

Tripod

Challenge

Difficult Detachment

RiSE: First Steps up the Wall

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

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

Feet Type

Rubber

Gait Type

Tripod

• Challenges
• Inadequate passive compliance
• Small gear ratio  Low speed

RiSE: First Steps up the Wall

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

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

Plexiglass

Carpet

Cork

• Surface properties dictate climbing trajectories
• Pull-in forces, attachment, detachment vary

RiSE: First Steps up the Wall

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

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

Tripod

Tetrapod

Pentapod

Rippled Tripod

RiSE: First Steps up the Wall

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

Tripod 1

Tripod 2

50%

50%

RiSE: First Steps up the Wall

Tripod 1a

Tripod 1b

Tripod 2

25%

25%

50%

RiSE: First Steps up the Wall

Set 1

Set 2

Set 3

33%

33%

33%

RiSE: First Steps up the Wall

Forward Tripod

Backward Tripod

RiSE: First Steps up the Wall

Tripod

Pentapod

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

RiSE: First Steps up the Wall

• 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

• - Drop the gears
• Actuate the tail
• Climb faster
• Climb outdoor surfaces
• Multi-purpose feet
• Horizontal ↔ Vertical
• Add Feedback

RiSE: First Steps up the Wall

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

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