Transcript P08023: Air Muscle Artificial Limb

P08023: Air Muscle Artificial Limb
Jonathan Kasper
Jenna Fike
Matt Lewis
Josa Hanzlik
Ellen Cretekos
Nick Rappa
Eric Giang
Mark McKann
Project Manger (ME)
Lead Engineer (EE)
Design Lead (ME)
Mechanical Engineer
Mechanical Engineer
Mechanical Engineer
Electrical Engineer
Mechanical Engineer
Sponsor: Dr. Kathleen Lamkin-Kennard
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P08023: Project Description
• Project Statement:
– “Develop a Scalable Robotic Limb that Accurately Models All
Degrees of Freedom of Human Fingers.”
• Market: RIT Biomechanical Program
– Showcase for New Technology
• Key High Level Needs / Engineering Specs
– Realistic Finger Motions
–
–
–
–
Reliability
Low Cost
Control Repeatability
Reliability & Serviceability
4 DOF in Fingers
# Tendons, # Muscles
Finger Displacement, +/- 10%
Air Muscle = $8 approx.
Supplied Air Pressure 30 psi.
Air Muscle Life Span
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P08023: Selected System Concept
LabVIEW
DAQ
Pressure
Valves
Air
Muscles
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Artificial Hand
P08023: Selected Limb Concept
DOF
Air Muscles
Controls Input
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P08023: Design/Build Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Wear issues between all
moving parts
– Tolerances on complex
parts
– Unnecessary friction is
prevented by loose
tolerances
– Seek assistance from RIT’s
machine shop
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P08023: Design/Build Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Minimal rework of parts is
necessary due to time
constraints
– CAD model used to verify
all aspects of design
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P08023: Design/Build Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Robustness of extension
ligaments must be
improved
– Air muscle output force
may exceed required value
– Extension ligaments are
very serviceable
– Connecting cable strength
can be tailored to demands
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P08023: Air Muscle Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Determining air muscle life
and serviceability
– Creep affecting air muscle
performance
– Life cycle testing to
demonstrate reliability
– Muscle organized on limb
to allow for serviceability
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P08023: Air Muscle Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Effect of temperature on
repeatedly cycled muscles
– Measure and determined
thermal effects on air
muscles
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P08023: Air Muscle Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Tubing abrasion due to
mesh contact
– Observe effects of mesh
abrasion
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P08023: Controls Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Control feedback system
lacks robustness
Sensor Body
– Different feedback sensors
will be tested to observe
sensitivity
Electrical Connections
+
+
Sensor Body
at Rest
Stretched
Sensor Body
Deforming
Force
Before
-
www.merlinrobotics.co.uk
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P08023: Controls Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– Team Lacks expertise with
interfacing control
components
– Solenoid valve
specification are not yet
determined
– Each interface junction will
be evaluated for
compliance
– There is room in the budget
for valve upgrades
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P08023: Controls Risk Assessment
• Sub-System Risks:
• Proposed Mitigation:
– LabVIEW is a new
programming language for
team
– Willing faculty members
and NI technical assistance
available
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P08023: Current State of Design
• Design is expected to meet all customer needs
– Verified through further testing and feasibility assessments
• Design meets all engineering specs for Design/Build subsystem:
– Further air muscle testing is required
– Final controls concept selection is required
– Addition controls input as a result of the detailed design review
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P08023: Feasibility Videos
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P08023: Feasibility Videos
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P08023: Feasibility Videos
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P08023: Budget Review
• On target to be under proposed project budget of $2500
– Higher priced valves may be chosen to supply smoother finger
motions
– Fingers will be made out of aluminum which will add to costs
• Sub-System Costs:
– Design/Build: $439.20
– Air Muscle: $68.13
– Controls: $1001
• Lead Time Concerns:
– Nothing longer than 2 weeks for materials
– Machining time is worked into schedule
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P08023: MSDII Sub-Systems Schedule
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P08023: MSD II Project Milestones
• Dec 16: Design finalized and all parts on order
• Jan 27: Functional alpha prototype (full featured)
• Feb 3: Design verification testing complete, initiate design
revisions
• Feb 10: Design review: Design Verification Testing Results
• Feb 17: Documentation Finalized: DHF, Formal Paper,
Poster
• Feb 24: Project Review - Phase 4 Completion
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