Design of a Variably Compliant Leg Using Design of a Variably Compliant Leg Using Shape Deposition ManufacturingShape Deposition Manufacturing

Viktor OrekhovTennessee Tech University

Cookeville, TN

SUNFEST 2007University of Pennsylvania

August 10, 2007

August 10 , 2007 Slide 2/12

Energetics

Stability

Robustness

ComplianceCompliance

Lessons from Nature

Passive Leg Control

Variable Stiffness

Control and Communication

Sensors

Position Control

Motor

Gearing

Flex Sensor

Rotary Pot

PICMicrocontroller

IRDA

August 10 , 2007 Slide 3/12

Design ChallengeDesign Challenge

Shape Deposition Shape Deposition ManufacturingManufacturing

Layered Prototyping Technique

Complex Designs

Multiple Materials

Embedded components

(Cham 1999)

August 10 , 2007 Slide 4/12

Leg DesignLeg Design

August 10 , 2007 Slide 5/12

Geared Slider Flex Sensor

Motor

Rotary Pot

Circuit Board

Battery

IRDA

Slider ActuationSlider Actuation

August 10 , 2007 Slide 6/12

Motor Insert

Pot Shaft

SlidersSliders

August 10 , 2007 Slide 7/12

Original

Nylon Rack

Laser Cut

SDM

Press Fit Design

Symmetric Stops

ElectronicsElectronics

August 10 , 2007 Slide 8/12

Flex SensorResistance vs. Deflection

12.9

13.4

13.9

14.4

14.9

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Deflection (mm)R

esis

tanc

e (K

ilohm

)

SDM AnimationSDM Animation

August 10 , 2007 Slide 9/12

Final ProductFinal Product

August 10 , 2007 Slide 10/12

AcknowledgmentsAcknowledgments

August 10 , 2007 Slide 11/12

Dr. Dan Koditschek

Dr. Jonathan Clark

Kevin Galloway

Sam Russem

Mulea Bereketab

QuestionsQuestions

August 10 , 2007 Slide 12/12