Transcript Presentation

BIOMIMETRIC CRAB
Bill Dwyer
Joe Mead
WEEK 3
Shaynae Moore
Casey O’Connell
BRAINSTORMING: PROJECT KNOWN'S (UPDATE)
Pinching motion needs to be quicker than flexion and
extension motion.
 We are modeling the Blue Crab
 Pneumatically powered
 3 muscles per claw
 Running of RIT house air
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Design for 40 psi (60 psi upper limit.)
Aquarium will be provided and sized according to our
size requirements.
 Low risk for exploding surgical tubing.
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High cyclical repeatability
Governing equations for McKibben muscles.
BRAINSTORMING: PROJECT UNKNOWNS (UPDATE)
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What materials will the crab be made out of?
How will the crab be encased?
Will our device move through locomotion?
What will the length of our muscles be?
How will the crab be designed so it will remain flush on the aquarium
floor
Will there be a cabin that will house the muscles or will they be located
on the underbelly of our device?
How will the range of motion intervals be incorporated
 Example (antagonistic muscle pairs?)
Blue Crab Species information and movement.
How rigid/buoyant will the umbilical chord become after pressurizing.
ENGINEERING
SPECIFICATIONS
(SEE SPREAD SHEET)
PROJECT RISKS
(SEE SPREAD SHEET)
CONCEPT DEVELOPMENT
Preliminary Biomimetic Crab design
•Pincher
• Claw
•Wrist
NOTE:
•This is underside of assembly to hide
Mechanics.
•The Left and right assemblies are mirror copies.
•Both assemblies will function simultaneously
and individually.
CONCEPT DEVELOPMENT
•The spring creates force required to open the pincher and keep it in
the rest phase.
•The McKibben muscles creates the force required to close pincher
CONCEPT DEVELOPMENT
•The Pincher control line passes directly over the wrist joint to minimize deflection
in wrist articulation
•The spring provides force that keeps wrist at neutral or zero angle of rotation
•The wrist is operated by two McKibben muscles to create positive and negative
rotation
CONCEPT DEVELOPMENT
Frame or Platform Design
•Simply flat plate design for easy mount of;
•Arm Assemblies
•Legs Assemblies
•McKibben muscles
•Aesthetic cover plates
CONCEPT DEVELOPMENT
Aesthetic Covering
•Cast fiberglass, foam or gel pieces
•Rubber “suit” the frame fit inside
•Worst case paint entire Crab