P14043-Smart CaneSenior Design

Final Presentation

Introductions

• Lauren Bell – Mechanical Engineer• Jessica Davila – Industrial Engineer• Jake Luckman – Mechanical Engineer• William McIntyre – Electrical Engineer• Aaron Vogel – Mechanical Engineer

Agenda• Problem Description• Design Challenge• System Design and Operation• Testing and Traceability• Project Process• Conclusion• Recommendations• Lessons Learned• Acknowledgements

Problem DescriptionSafe and easy navigation in the world is difficult for the blind and

deaf/blind

InexpensiveIntuitive

ExpensiveTraining Required

Limited Situation Feedback

Excellent Situation Feedback

COMMON SOLUTIONS

Project Goal

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 Consideration

s

• Defining the engineering requirements & constraints

Generation of Design

• Drawings, Documentation

Fabrication and Assembly

Testing of Prototype

• Proof that prototype meets eng. requirements

MSD I

MSD II

Design Considerations

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

Customer desires needed to be transformed into technical requirements…

Learned – Fully understand the customer needs ASAP…otherwise time will be wasted

Potential Concepts

• Track Ball• Piston Push Feedback• Torque ‘Jerk’• Magnetic Force Feedback• Scroll Navigation

Brainstorming and benchmarking yielded the following likely candidates…

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

Design provides effective directional feedback

• ‘Bump’ Roller Sub-assembly• DC gear motor• Roller arms• Dowel pins• Press fit ball bearings

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

Final tests were within predicted values

Testing and Traceability

Prototype meets all non-technical requirements

Testing and Traceability

Problem Tracking System

1. Identifying & Selecting

Problem

2. Analyzing Problem

3. Generating Potential Solutions

4. Selecting and

Planning Solution

5. Implementing

Solution

6. Evaluating Solution

Learned – Once problems started to arise and stack up, Problem Tracking significantly helped us manage the problems

Risk Curve

Useful tool to track actual status against planned

20-Aug 9-Sep 29-Sep 19-Oct 8-Nov 28-Nov 18-Dec 7-Jan 27-Jan 16-Feb 8-Mar 28-Mar 17-Apr 7-May0

10

20

30

40

50

60

70

80

90

Actual Planned

Sum

of R

isks'

Impo

rtan

ceIm

port

ance

= L

ikel

ihoo

d x

Seve

rity

Reduction of risks due to analysis (heat, stress, weight)

RISKS: Machining issues with thin ABS covers, ABS back cover breaks during testing phase, PCB not arriving on time

PCB working, assembly between handle & cane holds together, wires fit into handle design

Project Plan and Efficiency

TaskPlanned Duration

Actual Duration Difference Efficiency

Order Electrical Parts 14 21 7 67%Fabrication of Parts 18 34 16 53%Order PCB 5 30 25 17%Testing 5 18 13 28%Assembly of Handle 5 15 10 33%Technical Paper 14 27 13 52%Total MSDII Tasks 83 108 25 77%

Item Item Description Date Due Owner Date Complete Status1 Complete editing paper 30-Apr Jess 30-Apr Complete2 Add electrical section into paper 30-Apr BJ 30-Apr Complete4 Turn in Poster 28-Apr Lauren 28-Apr Complete5 IEEE Design Presentation Submit to Prof. Slack 29-Apr Team 30-Apr Complete6 Complete user manual 30-Apr Aaron 30-Apr Complete7 Edit paper based on Gary's revisions 6-May Jess 6-May Complete8 Complete final report for customer 12-May Team 12-May Complete9 Turn in Paper 8-May Jess 8-May Complete

10 Final Presentation 13-May Team 13-May Complete

Final Deliverables

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*• 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:• 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