Applying Principles from the Locomotion of Small Animals to the …bdml.stanford.edu/uploads/Honda/PresentationReport... · 2013-01-28 · Applying Principles from the Locomotion

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Applying Principles from the Locomotion of Small Animals to the Design and Operation of Robots

Mark Cutkosky Center for Design Research

Stanford University Stanford, CA

bdml.stanford.edu

Stryker Interaction Design Workshop September 7-8, 2005

2 1/28/13

Origins of bio-inspired design

•  Understanding the body as a marvelous machine

•  Understanding machine elements as examples of limbs, skeletons, muscles and tendons

Renaissance discovery:

Da Vinci notebooks

Da Vinci’s programmable spring-powered cart


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Why the recent proliferation of biomimetic designs?


4 1/28/13

Spatular shaft

2!m

Spatula

200nm

Setal shaft

100!m

Lamella

Cushions 1cm

1mm

Biology: better tools for understanding biological systems in detail


5 1/28/13

380µm Deposit (part)

Shape

Embed Deposit (support)

Shape

Part Embedded Component

Support

Engineering: better analysis tools, fabrication methods and materials

Synthetic dry adhesive: polymer molds from dual,

angled-exposure lithography + micromachining

SDM multi-material fabrication


Behaviors now: discrete, isolated


7 1/28/13

Biomimetics

Copy Nature

Evolution - “just good enough”

Natural Selection is

not Engineering

R.J. Full Dept. of

Integrative Biology, UC Berkeley

Lessons from biology for bio-inspired design:

1. Reduce Complexity - Collapse Dimensions

2. Manage Energy 3. Use Multifunctional Materials - Tuned,

Integrated & Robust

4. Exploit Interaction with Environment

R.J. Full

“Curse of Dimensionality”

Designs appear hopelessly complex No detailed history of design plans

230 Muscles

Full and Ahn, 1995

? Neurons 72 DOF

R.J. Full


Reducing dimensionality: the sagittal leg spring

Human

TWO- Legged

Cockroach

Legged SIX-

Crab

Legged EIGHT-

Dog

Legged FOUR-

B o d y W e i g h t

Cavagna et al., 1977

Full and Tu, 1990 Blickhan and Full, 1987

R.J. Full

vertical force

fore-aft force time


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Lessons from Biology

1. Reduce Complexity - Collapse Dimensions

2. Manage Energy 3. Use Multifunctional Materials - Tuned,

Integrated & Robust

4. Effective Interaction with Environment


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Deposit (part)

Shape

Embed Deposit (support)

Shape

Part

Embedded Component

Support

Shape Deposition Manufacturing (SU/CMU)


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Leaf-spring

Piston

Sensor and circuit

spacer

Valves

1. Support material 2. Part material 3. Embedded sensor 4. Part material 5. Embedded parts 6. Part material 7. Top support*

Detail of part just after inserting embedded components

Robot leg with embedded actuator, valves, sensor and circuitry

Finished parts Sequence of geometries for fabrication

Embedded components

[Cham et al. 1999]


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SDM: part number reduction, increased robustness, controlled compliance, damping

Left: Kinematic prototype of linkage with 31 parts Center: SDM linkage with thick flexures, 1 part Right: SDM linkage with fabric-reinforced flexures


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Biological Inspiration

•  Control heirarchy – Passive component – Active component

Full and Koditschek, 1999

Mechanical System

(muscles, limbs)

Environment

Mechanical Feedback (Preflexes)

Sensory Feedback (Reflexes)

Neural System (CPG)

Feedforward Motor Pattern

Passive Dynamic Self-Stabilization

Locomotion


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Solution Approach: Analyze and “Optimize” Dynamic Model in ADAMS

3D model with geometric similarity to robot - Rigid body with six legs - Linear pneumatic actuators (with valve delays) - Spring-damper rotational joints in sagittal plane - Friction and ground contact models


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Study biological materials, components, and their roles in locomotion.

Study Shape Deposition Manufacturing (SDM) materials and components.

Models of material behavior and design rules for creating!SDM structures with desired properties!

Example: mapping from passive mechanical properties of insects to biomimetic robot structures

ServoMotor

Roachleg

Displacement InputForce Output

stiff material!

viscoelastic material!


18 1/28/13

ServoMotor

Roachleg

Displacement InputForce Output

Study biological materials, components, and their roles in locomotion.

Study Shape Deposition Manufacturing (SDM) materials and components.

Models of material behavior and design rules for creating!SDM structures with desired properties!

Hysteresis loop @10Hz!

Example: mapping from passive mechanical properties of insects to biomimetic robot structures

-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 -6

-4

-2

0

2

4

6

position (mm)

Forc

e (m

N)

Data Model


19 1/28/13

Bioinspiration how do they

do it?

Biology examine literature, work with biologists

Robotics implementations of principles

SDM technology

2. Bioinspiration for smooth climbing

Analysis test and analyze results

refinement

FT

FN

Hypotheses regarding the

principles at work


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Principles for climbing with dry adhesion

2. Directional adhesives

1. Hierarchical compliance

3. Distributed force control


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Compliant peeling toe

Living hinge

Hard polyurethane

Soft poly-urethane

Fiber mesh embedded

Tendon (steel cable)

Teflon tube

Directional Polymeric Stalks


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Anisotropic gecko adhesion

25 mN of Adhesion

Gecko setae dragging with curvature

-30

-20

-10

0

10

20

30

40

50

0 1 2 3 4

Time (s)

Forc

e (m

N)

Colored: Normal force Gray: Shear force

Dragging against curvature

No Adhesion

Time (s)

Forc

e (m

N)

-30

-20

-10

0

10

20

30

40

50

0 1 2 3 4


23 1/28/13

Gecko Force-Space Results

Load, then pull off at various angles, and measure force ! limit curve

-10 0 10 20

-10

0

10

20

Tangential Force (mN/stalk)

Normal Force (mN/stalk)

500µm

-10 0 10 20

-10

0

10

20



500µm600µm

-10 0 10 20

-10

0

10

20



500µm600µm700µm

loaded with stalk angle: adhesion ~ tangential stress

loaded against stalk angle: Coulomb friction

safe region

Autumn et al. JEB 2006

Fn

Ft

compression

adhesion


24 1/28/13

Force Control optimal strategy for inverted surface

Frictional Adhesion Johnson-Kendall-Roberts

Rear Foot Flipped

FN

FT

FN FN FN

FT FT FT

Generalization: Formulate as linear programming problem to control foot orientation & internal forces for arbitrary loading conditions [Santos, JAST09].


25 1/28/13

Control foot orientation + internal forces


26 1/28/13

Directional adhesion facilitates control of forces for smooth, efficient locomotion

Tangential force

Nor

mal

For

ce

Contact force limits

Safe force region

Desired loaded state

Desired attach/detach state

The gecko’s hierarchical adhesive system spans length scales from 1 cm to 100 nm.

Current work: compliant hierarchical structures

380µm

Synthetic adhesives require hierarchical, directional compliance to conform to rough surfaces and distribute loads over large areas.

20 µm wedges atop 380 µm directional stalks (SEM photo)


28 1/28/13

Stanford hierarchical, directional adhesive !"#$%&'()*+,'*-.$#+/0)*12+3!,/4+

!,/+

5"%#'6$78$2+

9"$#)#%:"%)*+/-20$.+

;<+


29 1/28/13

Bio-Inspired?


How to get nearly uniform loading over the entire toe, with tolerance to a range of loading angles?

Lamella

Bio-Inspiration

Phalanges

Lamellae

Fluid-filled sac

Lateral digital tendon

Lateral digital tendon

(Russell J. Morphology 1982)

Stryker Interaction Design Workshop September 7-8, 2005 31

Loading angles: alignment compensation

4 leg version of RiSE platform

4 kg gross loads


Scaling to larger areas and loads: tiled arrays

adhesive

rigid tile

pressurized

sac

pressure

plate

main tendontile tendon

compliant

supportstructure

pulley

40 kg

Approx. 80cm2

Stryker Interaction Design Workshop September 7-8, 2005 33

Scaling to larger areas and loads: results


This work has been supported by the RiSE program (DARPA BioDynotics N66001-03-C-8045) with additional support from NSF NIRT (ID 0708367) and COINS (UCB)

Robots in Scansorial Environments (RiSE)

Acknowledgements

Documents

Applying Principles from the Locomotion of Small Animals to the …bdml.stanford.edu/uploads/Honda/PresentationReport... · 2013-01-28 · Applying Principles from the Locomotion