Smart Cane – P14043Systems Design Review

Lauren Bell, Jessica Davila, Jake Luckman, William McIntyre, Aaron Vogel

Agenda• Project Background• Customer Requirements• Engineering Requirements

• Functional Decomposition• Concept Generation [Morph chart and Pugh charts]• Concept Selection• Engineering Analysis• Risk Assessment• Test Plan• Project Plan

Why Design a Smart Cane?Conventional White Cane

Advantages Disadvantages

Inexpensive and available Slow navigation – user must guide himself/herself

Little/no training

User can “feel” the environment

Guide AnimalsAdvantages Disadvantages

Takes commands Expensive

Detects overhanging and tricky obstacles Can get sick/hurt

Guides user Training for animal and user

Long waiting lists

Sometimes not allowed (illegally) in some situationsUser cannot “feel” environment

Ultimate Vision of Smart Cane

Smart CaneCombined Advantages

Less expensive than guide animal, available, easily replaceable

Little/no training

User can still “feel” the environment

Guides the user (haptic feedback)

Capable of detecting objects not easily felt through conventional cane

Longer range beyond cane tip

Possibility to integrate with other navigation technologies (GPS, stored paths, maps, etc…)

For Our Project…Our project will focus on these areas:

Future projects will continue towards final Smart Cane vision…

Smart CaneCombined Advantages

Less expensive than guide animal, available, easily replaceable

Little/no training

User can still “feel” the environment

Guides the user (haptic feedback)

Capable of detecting objects not easily felt through conventional cane

Longer range beyond cane tip

Possibility to integrate with other navigation technologies (GPS, stored paths, maps, etc…)

Customer Requirements• Since Problem Definition Review

• Emphasis on the haptic handle

• Less emphasis on detection system• (Make it basic, detect lower-front objects, leave for future projects)

• Future projects:• Detection System• Resembles a conventional cane• Operated like conventional cane• Improving battery life, robustness, use in other environments etc…

Engineering RequirementsRevised, concise specs:

• Cane characteristics• Moment of Inertia• Spring Constant• Handle diameter• Length

Concept Generation

Functional Decomposition

Morph Chart

Cane Structure – Pugh ChartPlastic Wood Aluminum Fiberglass Carbon fiber

Low Density S S - Datum +

Transmits vibrations/sound - + + Datum S

Corrosion Resistant S - S Datum S

Low Cost + + - Datum -

Ease to work with and modify + S S Datum S

Safe for use S - S Datum S

+ 2 2 1 1

- 1 2 2 1

Concept Selection – Handle*

Attractive/Repulsive Magnetism Navigation

Pros• Easier to feel direction• Better directional

feedback• Can be used with gloves

Cons• Possible power limitations• No indication of proximity

(acting alone)

Wire windings with ferrous cores

Microcontroller

Battery housing

Screw-in cap

Piston Navigation

Pros• Easier to feel direction• Better directional feedback• Can be used with gloves

Cons• Heavier• No indication of proximity

(acting alone)• May inhibit index finger

haptic ability

Standard servo

Push piston

Drive shaft

Battery Housing

Microcontroller

Screw-in cap

Scroll Navigation

Pros• Easier to feel direction• Better directional feedback• Can be used with gloves

Cons• May inhibit index finger

haptic ability

Screw-in cap

Battery Housing

Microcontroller

Continuous servo

Scroll Transmission

Track Ball Navigation

Pros• Easier to feel direction• Better directional feedback• Can be used with gloves

Cons• Heavier• Less compact• May inhibit index finger

haptic ability

Screw-in cap

Microcontroller

Battery Housing

Continuous servos & transmission shafts

Track ball

Torque Handle Navigation

Pros• Easier to feel direction• Better directional feedback• Can be used with gloves

Cons• Heavier• Moment of inertia/torque

concern

Screw-in cap

Standard servo

Transmission

Microcontroller

Battery housing

Handle Feedback – Pugh Chart

Vibration Motors

Navigation by Track ball

Handle Expansion by

Push Cylinders

Handle Twist via Torque Motors

Handle Expansion by Electroactive

Polymers

Thermoelectric/Heat in handle

Ring attached to a motors to

move finger/Rotating band that slides

across finger

Electromagnets control finger

direction

Easy to Feel Direction Datum + + + + + + +

Provides Directional Feedback Datum + + + + + + +

Safe to use Datum S S S S - S SCompact Design Datum - S S - - S S

Lightweight Datum - - - - - S S

Affordable within our budget Datum S S S - S S S

Fast Response time Datum S S S - - S S

Easy for users to learn within our time frame Datum S S S - S S S

Able to be used with gloves Datum + + + + - + +

Indicates proximity Datum S - S - - S S+ 3 3 3 3 2 3 3- 2 2 1 6 3 0 0

Detection System – Pugh ChartUltrasonic

SensorUltrasonic Sensor w Accelerometer Infrared sensor Radar System Image

Processing Laser

Light Weight Datum - S S S S

Power Consumption Datum - + S - -

Gives good signal for range Datum S - - S S

Sensitive to Objects close/far away Datum S - - S S

Fast Response time Datum - S S - +

Durable Datum S + - S S

Small in size Datum S + S S -

Able to detect all objects Datum S - - + -

Cost Datum S S S - -

Easily Senses object location Datum + - S S -

+ 1 3 0 1 0

- 3 3 3 3 4

Engineering Analysis• Microcontroller • Power• Operating Conditions• CPU Speed• I/O Characteristics

• Servo Motors• Torque• Weight• Dimensions• RPM• Tolerance/Precision• Power • Continuous/Standard

• Magnets• Forces• Weight• Dimensions• Power

• Batteries• Heat• Battery Life• Power• Rechargeable vs.

Disposable • Size

Risk AssessmentImportance Risk Likelihood Severity

6 Burning out micro controller 3 2

6 Software is ineffective 2 3

6 Haptic handle and detection systems integration issues 2 3

6 Not meeting customer expectations 2 3

4 Not obtaining parts on time 2 2

4 Battery malfunction 2 2

4 Over budget 2 2

3 Cane does not stay together, durability failure 1 3

3 Not completing software component 1 3

3 Haptic forces not being strong enough 1 3

3 Hardware and software integration 1 3

3 Detection is ineffective 1 3

3 Uncoordinated team schedules 3 1

3 Team Member leaves team 1 3

3 Cane gets dropped repeatedly on the ground 1 3

3 Excessive tapping 1 3

1 System is too heavy for desired cane weight 1 1

64 TOTAL 27 43

Test Plan• User Test

• Battery Test

• Physical Characteristics

• Detection System Test

Project Plan

Problem Definition

• Problem Statement

• Customer Requirements

• Engineering Requirements

System Design

• Benchmarking• Functional

Decomposition• Concept

Generation• Risk Assessment• Test Plan• Engineering

Analysis • Concept

Selection

Subsystem Design

• Proof of Concept

• Subsystem Decompositions

• Subsystem Design and Analysis

• Updated Test Plan

• Updated Risk Assessment

Detailed Design

• Hardware and Software Design

• Updated Risk Assessment

• Updated Test Plan

Completed Design

• Completed Design

• Assembly Process

• BOM• Budget POs• Test Plan

Three Week PlanSunday Monday Tuesday Wednesday Thursday Friday Saturday

9/29 9/30 10/1 10/2 10/3 10/4 10/5

10/6 10/7 10/8 10/9 10/10 10/11 10/12

10/13 10/14 10/15 10/16 10/17 10/18 10/19

10/20 10/21 10/22 10/23 10/24 10/25 10/26

Select Concept

Proof of Concept

Engineering Analysis

Engineering AnalysisSubsystem Decomposition/Analysis

Subsystem Decomposition/ Analysis

Subsystem Design

Update Test Plan and Risk Assessment

Update Test Plan and Risk Assessment

Systems Design Review

Sub Systems Design Review

Questions?

Project Plan