Robot Fabrication

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Robot Fabrication
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Shape Deposition Manufacturing

• Add and Remove material relatively arbitrary
  geometries
• Mill accuracy for external and internal surfaces

Deposit (part)
Shape
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SDM Process

• Can also embed components

Pressure Transducer
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SDM Process

• Can spatially vary material properties within
  and between layers

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SDM Process

• Material Properties and Database

cdr.stanford.edu /biomimetics/sdm.html
Material Considerations
Machinability Minimal shrinkage Bonds to self Low
viscosity Low curing temperature Strength/stiffnes
s
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State of the Art Sept. 1999

• Manufacturing

Embedded components Multiple-materials
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State of the Art - Sept. 1999

• Robot prototypes Old Sprawl

Passive compliant hips Walks well No control
of direction or amount of compliance Ad hoc
construction No SDM
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Goal for Aug. 2000 SDM Robot

• Compliant hip
• Feedforward
• Alternating tripod
• Stable running
• Obstacle traversal

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SDM Robots

• 1st SDM leg

Limited control of amount and direction of
compliance Imbedded connectors and
piston Reproducible, but non-functional design
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SDM Robots

• 1DOF leg

One primary direction of compliance Works very
well, robust Currently investigating the effect
of varying compliance
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SDM Robots

• 2 DOF legs

Linear and Rotational DOFs Can independently
control direction and amount of compliance
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Spatial 4-bar Mechanism
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SDM Process Planning
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Current Work

• Modular Compliance

Can manually swap flex segments 10 different
levels Is being used to test the effects of
varying the stiffness of the leg
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Current Work

• Modular Bodies

Can manually swap Servo Motors and
Valves Embedded electronic backbone Robust
packaging
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Future Work

• Foot Design

Design feet for optimal ground contact Embed
contact/force sensors into legs Feed back for
adaptation
Jorge failed feet
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