P14043-Smart Cane
Senior Design
Final Presentation
Introductions
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Lauren Bell
Jessica Davila
Jake Luckman
William McIntyre
Aaron Vogel
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Mechanical Engineer
Industrial Engineer
Mechanical Engineer
Electrical Engineer
Mechanical Engineer
Agenda
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Problem Description
Design Challenge
System Design and Operation
Testing and Traceability
Project Process
Conclusion
Recommendations
Lessons Learned
Acknowledgements
Problem Description
Safe and easy navigation in the world is difficult for the blind and
deaf/blind
Project Goal
Inexpensive
Intuitive
Limited
Situation
Feedback
Expensive
Training Required
COMMON SOLUTIONS
Excellent
Situation
Feedback
Design Challenge…
…To design, fabricate, assemble and
validate a ‘haptic handle’
• To be attached to a traditional cane
• Provide directional feedback to blind and deaf/blind users
MSD Process Overview
Concept
Selection
• Many ideas to one
Design
Considerations
• Defining the
engineering
requirements &
constraints
Generation of
Design
MSD I
• Drawings,
Documentation
Fabrication
and Assembly
MSD II
Testing of
Prototype
• Proof that
prototype
meets eng.
requirements
Design Considerations
Customer desires needed to be transformed into
technical requirements…
Customer Desire
Technical Requirement
Light weight
< 1 lbs.
Small Grip Diameter
< 1.5 inches
Quick Signal to User
< 500 milliseconds
User Can Detect Direction
*Will Elaborate Later
Battery Life
> 4 hours
Learned – Fully understand the customer needs ASAP
…otherwise time will be wasted
Potential Concepts
Brainstorming and benchmarking yielded the
following likely candidates…
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Track Ball
Piston Push Feedback
Torque ‘Jerk’
Magnetic Force Feedback
Scroll Navigation
Learned – Prototyping accelerates the concept selection process
Optimizing Roller Design
• Roller Speed
• Roller Shape
• Bump Height
Learned – Quick and simple tests/prototypes will quickly
narrow the design. Don’t overanalyze!
Electrical Design
Electrical design driven by
mechanical design and
Engineering requirements
Mechanical Design
• ‘Bump’ Roller Sub-assembly
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DC gear motor
Roller arms
Dowel pins
Press fit ball bearings
Design provides effective
directional feedback
Final Design
Documentation of everything is crucial for future project
iterations
Fabrication and Assembly
• ~25 manufactured parts
• Material Changes
• Part Modifications
• Time management
Learned – Fabrication and
assembly will expose necessary
changes in the design
Testing and Traceability
Final tests were within predicted values
Testing and Traceability
Prototype meets all non-technical requirements
Problem Tracking System
1.
Identifying
& Selecting
Problem
3.
Generating
Potential
Solutions
2.
Analyzing
Problem
5.
Implementing
Solution
4. Selecting
and
Planning
Solution
6.
Evaluating
Solution
Learned – Once problems started to arise and stack up, Problem
Tracking significantly helped us manage the problems
Risk Curve
Sum of Risks' Importance
Importance = Likelihood x Severity
90
Reduction of risks due to
analysis (heat, stress,
weight)
80
70
60
RISKS: Machining issues
with thin ABS covers, ABS
back cover breaks during
testing phase, PCB not
arriving on time
50
PCB working, assembly
between handle & cane
holds together, wires fit
into handle design
40
30
20
10
0
20-Aug
9-Sep
29-Sep
19-Oct
8-Nov
28-Nov 18-Dec
Actual
7-Jan
27-Jan
16-Feb
8-Mar
Planned
Useful tool to track actual status against
planned
28-Mar 17-Apr
7-May
Project Plan and Efficiency
Final Deliverables
Item
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Item Description
Complete editing paper
Add electrical section into paper
Turn in Poster
IEEE Design Presentation Submit to Prof. Slack
Complete user manual
Edit paper based on Gary's revisions
Complete final report for customer
Turn in Paper
Final Presentation
Task
Order Electrical
Parts
Fabrication of
Parts
Order PCB
Testing
Assembly of
Handle
Technical Paper
Total MSDII
Tasks
Date Due
30-Apr
30-Apr
28-Apr
29-Apr
30-Apr
6-May
12-May
8-May
13-May
Owner
Jess
BJ
Lauren
Team
Aaron
Jess
Team
Jess
Team
Planned Actual
Duration Duration Difference
Date Complete
30-Apr
30-Apr
28-Apr
30-Apr
30-Apr
6-May
12-May
8-May
13-May
Efficiency
14
21
7
67%
18
5
5
34
30
18
16
25
13
53%
17%
28%
5
14
15
27
10
13
33%
52%
83
108
25
77%
Status
Complete
Complete
Complete
Complete
Complete
Complete
Complete
Complete
Complete
Imagine RIT
• 200+ “Users”
• ~100% Positive Feedback
• University News Interview
Users at Imagine RIT demonstrated our project
met its objectives and was a success.
Lessons Learned
Project Management
Customer Interaction
Creating a good team dynamic
“What’s the best thing I can be doing right now?”
Recommendations
• Complete cane with integration to sensors
• Improve handle to provide feedback on changes in elevation
and proximity of obstacles.
• Redesign handle with fewer parts and simple assembly
• Attempt to redesign with smaller batteries
• Strengthen the outer structure of handle
• Water/weather proof
Recommendations for MSD
→Shorter presentations in MSD I
→Teach project management skills in other courses
→Evenly distribute the team resources
→Use guides from industry
Acknowledgements
• Guides
• Gary Werth
• Gerry Garavuso
• Customers
• Dr. Patricia Iglesias
• Gary Behm
• Tom Oh
• Professor Mark Indovina
• Jeff Lonneville
Motor Analysis
• Torque/speed
• Power consumption
Design Grip Pressure Spec
• Ensure handle functions under excessive grip
• Measure pressure of displaced air for rough idea
• Median pressure ~3 psi
• Compare to Grip Pressure Study*
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FSR sensors on glove
“Crush grip” measured on 50mm diameter handle
5 male and 5 female adults
Maximum pressure ~3.1 psi
• Our measurements matched the study, therefore:
• Marginal Grip Pressure: 3 psi
• Maximum (Design) Pressure: 5 psi
* Tao Guo qiang; Li Jun yuan; Jiang Xian feng, "Research on virtual testing of hand pressure distribution for
handle grasp," Mechatronic Science, Electric Engineering and Computer (MEC), 2011 International Conference
on, pp.1610,1613, 19-22 Aug. 201
Required Motor Torque
• Maximum moment could happen when:
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Grip reaches design pressure
Pressure force is perpendicular to contact point
Palm contact area is maximum on roller
Two rollers are contacted
• Maximum moment caused by design pressure
• 50.1 oz-in
• Motor selection will not be heavily constrained
• Variety of motors that meet torque, size and rotation requirements
Bump Rotation/Roller Analysis
• Bumps per rotation
• Servo to Roller Spacing
• Effectiveness of our
model – Audience?
Roller Force/Stress Analysis
Force/Stress Cont’d