VIRTUAL REALITY DATA GLOVE

Sub-System Design Review

MSD1

Group P14546

IntroductionsName Role

Corey Rothfuss Team Leader

Kayla King Mechanical Engineer

Josh Horner Mechanical Engineer

Ryan Dunn Electrical Engineer

David Yoon Electrical Engineer

Matthew Nealon Electrical Engineer

Cody Stevens Electrical Engineer

Agenda Project Overview - Background System Design Review

Current Concept System Function Decomposition Final Concept Selection Concept and Architecture development

Subsystem Design Subsystem Functional Decomposition Mechanical Design Electrical Design Software Design Bill of Materials (BOM) with Estimated Cost

Proof-of-Concept Engineering Analysis Risk Assessment Test Plan Project Plan

Background

Problem Statement Current State

Current techniques use active markers with cameras to track hand motion

Desired State The project will focus on providing a functional prototype that is

lightweight, durable, and relatively inexpensive The glove will not interfere with user’s natural hand movements Sensors transmit motion data to the computer for analysis

Project Goals Analyze current designs Identify opportunities for improvement of benchmarked designs

○ Lighter○ Better data rate○ More accurate○ More sensors

Constraints Must be able to stay within budget means

Current Concept Virtual Reality is used to simulate 3D environments using

multiple cameras, sensors, and immersive displays Most people know it from video games but it can be used for

research applications Relate eye movements to their corresponding body movements Training in specialized tasks Healthcare

Current techniques use markers in combination with cameras to track hand motion

In some positions, markers are occluded from optical view, resulting in missing data points

Current Concept

Additional Deliverables

Functional Prototype that will be used in the center for imaging science for the Virtual Reality room

Test Data verifying correct operation User manual for operation

Stakeholder(s) Primary Customer: Gabriel Diaz

Contact: Gabriel.Diaz@rit.edu 585-317-3595 Secondary Customer: Susan Farnard

Contact: Farnard@cis.rit.edu 585-475-4567 Faculty Guide: Ed Hanzlik

Contact: echeee@rit.edu 585-475-7428 Sponsor (financial support): RIT

Open Items From Last Review

Refine Customers needs, Engineering Requirements

Purchase Flex Sensors for feasibility studyPurchased 5 sensors to test

Find budget and how to distribute between MSD I and II30/70 split

Update Functional Decomposition to subsystem level

Customer RequirementsCustomer Rqmt. # Importance Description Comments/Status

CN1 9Provides accurate data about first metacarpal- phalangeal joint flexion (finger joints at the base of the fingers, closest to the wrist)  

CN2 9Provides accurate data about proximal inter-phlangeal joint flexion (the middle joints of the finger)  

CN3 9 Provides accurate data about rotatation of the wrist  

CN4 1 Provides accurate data about bending of the fingertip joint  

CN5 1 Provides accurate data separation of the fingersnot a priority, nice if possible within

time/budget constraints

CN6 9 Provides accurate data about flexing of the wrist  

CN7 9 Tracks grasp rate and grasp time of the hand  

CN8 9 Angle measurements are within a couple degrees  

CN9 9 Provides calibration routine (i.e. to map from sensor voltages to joint angles)  

CN10 9 Data rate of at least 60Hz  

CN11 1 Communicates wireless with computer  

CN12 9 Latency time of no more than 50ms  

CN13 9 Any connecting wires must be 20ft long  

CN14 9 Outputs data to current Python-based system  

CN15 9 Any batteries being used must be removable  

CN16 9 Does not impede movement more than a standard medium-weight glove  

CN17 9 Fits a range of hand sizes, especially the sizes of college students. small, medium, and large sizes

CN18 9 Lightweight Does not weigh the hand down

CN19 9 Quick start-up Turn on and put glove on

CN20 9 Reliable operation - will not fail during data collection  

CN21 9 Safe to useDoes not electrocute user or cut/scrape

user with use

CN22 3 Easily repairable  

CN23 3 If only one glove can be prototyped, it should be the right hand  

CN24 1 Keep gloves from getting sweatymostly Dr. Diaz's responsibility (He will

address when prototype is made)

Engineering Requirements

System Design

Alternatives Considered

Selected ConceptConcept #1

Pros: Uses Flex Sensors

Finger flexion Wrist flexion

○ Commonly used in other models currently on the market

Camera Markers for wrist rotation Lightweight Accurate

Positional Sensors Fits multiple hand sizes without the need for multiple gloves

Cons: Springs for finger separation

May not be safe May impede natural movement

Alternatives Considered

Selected ConceptConcept #4

Pros: Camera Markers for wrist rotation

Lightweight Accurate

Adjustable Knuckles Fits multiple hand sizes without the need for multiple gloves

Sensors between fingers Safer than springs

Skeleton figure Easily repairable

Cons: Uses Hall-effect Sensors

Finger flexion Wrist flexion

○ Not as accurate as flex sensors

Sensors between fingers May impede natural movement

Final System Design Concept

Concept Details Measures Finger Flexion

Flex Sensors Measures Wrist Flexion

Flex Sensors Measures Wrist Rotation

Active Camera Markers on Forearm Measures Finger Separation

Abduction Sensors (Flex Sensors) Placing sensors on hand

Glove Adjust to hand sizes

Adjustable bend points Transmit Data

USB Pre-Process Filter

Notch Filter Collect Data

MSP 430 development board

Concept Architecture

User Glove/Wrist Assembly

Sensors• Fingers/Wrist

Processor Computer Interface

Outputted Data

Power Supply

Subsystem Design

Track Hand Movement

Put accessories

on Wrist

Secure measurement instruments

Adjust to arm sizes

Put on Hand

Secure measurement instruments

Adjust to hand sizes

Measure movement

Measure Wrist Flexion

Mount Sensor

Locate Sensor

Connect Wires

Measure angle of finger flexion

Mount Sensor

Locate Sensor

Connect Wires

Measure twist of wrist

Mount Markers

Locate Sensor

Connect Wires

Measure Span of fingers

Mount Sensor

Locate Sensor

Connect Wires

Connect to Computer

Transmit Data

Process Data

Collect Sensor Data

Functional System Decomposition

Measure Wrist Flexion

Mount Sensor

Keep in correct Orientation

Make sure bend points are correct

Locate Sensor

Calibrate Sensor

Connect Wires

Connect Wire Terminals to

Microcontroller

Functional Sub-System Decomposition

Measure angle of finger flexion

Mount Sensor

Keep in correct Orientation

Make sure bend points are correct

Locate Sensor

Calibrate Sensor

Connect Wires

Connect Wire Terminals to

Microcontroller

Functional Sub-System Decomposition

Measure twist of wrist

Mount Markers

Keep in correct

Orientation

Locate Sensor

Calibrate Markers

Connect Wires

Connect Wire Terminals to

battery source

Functional Sub-System Decomposition

Measure span of fingers

Mount Sensor

Keep in correct Orientation

Make sure bend points are correct

Locate Sensor

Calibrate Sensor

Connect Wires

Connect Wire Terminals to

Microcontroller

Functional Sub-System Decomposition

Put Accessories on wrist

Mount wristband

Place microcontroller on top of wrist

Keep wires free from movement

Adjust to wrist Sizes

Attach/Detach from wrist

Connect Wires

Connect Microcontroller

wires to flex sensor

Functional Sub-System Decomposition

Connect to Computer

Transmit Data

Pre-Process

Filter out noise from surrounding

equipment

Program Microcontroller to convert signal to

bended angle

Collect Sensor Data

Define Input Range

Define Sampling Frequency

Functional Sub-System Decomposition

Mechanical Design Gloves

Between a baseball glove, lacrosse glove, and BMX glove CAD Model of hand○ Needs to be rigid enough to hold the sensors in the correct

orientation○ Needs to be able to move all five fingers and wrist without

restricting hand movementsThis will be more easily evaluated through experimentation rather

than theoretical calculations

Mechanical Design Wrist/Arm Assembly

A Flat, Plastic wrist piece that is similar to a large watch to hold the microcontroller and wiring

Similar to Cybergloves wristband

A sleeve (like a shooting sleeve in basketball) with active marker sensors will be used to measure wrist rotations

Location of flex sensors

Flex Sensor Sensor Circuitry

Instrumentation amplifier Analog Filter

Analog to Digital

Conversion

Sample and process data

Transmit Data

Electrical Design Flex Sensor

System Architecture

Electrical Design Circuit Typology

Voltage Divider Implementation Wheatstone Bridge Implementation

Electrical Design Circuit Typology (Continued)

Instrumentation Amplifier

Electrical Design Flex Sensors

Spectra-symbol 2.2”

Electrical Design Flex Sensors

Neoprene Flex Sensor

Software Design Code interface with ADC Digital Filtering and Data Conversion Communication Protocol

Bill of Materials

Name of ItemItem Number Description Vendor Manufacturer

Unit Cost Quantity

Total Cost

2.2" Flex Sensor SEN-10264 Flex Sensor Spark Fun Spectra Symbol 7.95 22 174.9

Neoprene Sensors NFS-01 Abduction sensor Images SI Images SI 15 10 150

MicrocontrollerMSP-EXP430G2

Microcontroller Dev. Board Mouser TI 10.99 2 21.98

Wiring Wiring RIT RIT 0 0

Gloves G1 GlovesMS Superstore EVS 45 1 45

Hand Bust HB1 Hand Bust-3D Print RIT RIT 0 2 0

Wrist Strap WS1 Wrist Strap-3D Print RIT RIT 0 2 0

Active Markers AM1 LED Active Markers RIT CIS Dr. Diaz 50 6 300

Sleeve S1Sleeve to Place active markers UA UA 15 2 30

Total $721.88

Note: This is for two hands (worst case price)

Proof-of-Concept Oscilloscope data of flex sensor – 4.5” Spectra

Symbol

Risk AssessmentTechnical

ID Risk Item Effect CauseLikelihoo

d

Severity

Importance

Action to Minimize Risk Owner

1Too much interference from electrical noise

Inaccurate dataHigh density of

electronic devices, lack of shielding

9 3 27More advanced signal filter

techniquesEE

2Weight of glove is

unmanageableRestricts natural hand

movementToo much weight from

sensors3 9 27

Make the glove lighter, find more lightweight sensors

Team

3 Technical ExpertiseNeeding to do more

researchNot enough competency

do the required task9 1 9

Seek out help, Use online resources, speak with

guides and champions, teammates

Team

4Conflicting Customer

NeedsNot being able to

meet goals

Budgetary, expertise, time, or physical

restrictions3 3 9

Talk to Professor Diaz and Ed Hanzlik and discuss

options of either alternate plans or lowered

expectations for deliverable goals

Team

5Flex Sensor does not

produce repeatable dataInaccurate data Poor Sensor Selection 3 3 9

Re-iterate Sensor selection process

EE's

6 Sensors Break or Kink Inaccurate/Loss data User Malpractice 3 3 9 Better User Training Dr. Diaz and Team

7 Wires Disconnect or breakLoss of that finger's

dataFatigue 3 3 9 Strongly secure wiring EE's

8 Sensors Lose Orientation Inaccurate data Different Finger Sizes 3 3 9Proper Sensor supports and

placementME's

9 Eval Board Bug System Crashes Poor Code 3 3 9 Test Code EE's

10Electrical components

shortsDamage to the

electrical componentsMishandling of

electronics1 9 9 Proper Safety Procedure EE's

11 Glove tear or ripCompromise of

structureFatigue 1 9 9

Proper Glove Selection and care

ME's

12Change in Customer

NeedsNot being able to

complete that goal

New programming language, lab went

wireless, etc. 3 1 3

Adapt to the new needs and discuss options of meeting

those goals. Frequent communication with

professor Diaz

Customer/Team

13Selected concept needs

adjustment(s)Lose valuable time Poor concept selection 1 3 3

Re-iterate concept selection process

Team

Risk AssessmentNon-Technical

ID Risk Item Effect Cause

Likelihood

Severity

Importanc

e

Action to Minimize Risk

Owner

1Scheduling Conflicts

Can’t get together to do important team

tasks

7 people with different

schedules9 3 27

Updating Google Calendars,

facebook, text, etc. Find a time to meet

Team

2 What if the budget is too low

Not being able to complete the

project

Not having enough funding

3 9 27

Find out budget early, benchmark research

costs, order on time to save on delivery costs

Team

3 Distributing work

People are idle and one person is

overworked

One person task but heavy workload

9 1 9

Others focus on others aspect of projects. Iterate

project planning and estimate the time it

will take

Corey

4Lead time for parts

too longLose valuable

time

Don’t order it early enough, Chose USPS

3 3 9Choose, FedEx,

UPS, or DHL. Order it early

Team

5Underperforming Team member

His share of work is not completed

Too busy, lazy, etc.

3 3 9Communicate with

team and guideTeam

6 Poor Planning

Not knowing what/when it is due, missing deliverables

Poor project plan, poor

communication, unclear goals

3 3 9

Make a well done project plan, iterate on the project plan, consult with guide

and customer

Team

7 Allergic to gloveAllergic

Reaction or…….. Death

no caution warning in user

manual1 9 9

Create warning in user manual

Team

8 Setback Time

Not being able to meet critical deadlines/deliv

erables

First project was cancelled and

lost critical time3 1 3

Schedule additional meeting times to make up for the

time allotted

Team/Hanzlik

Engineering Analysis Needed Determine best glove to minimize wear while retaining

comfort For not restricting natural hand movements and to be comfortable To be breathable to keep from excessive sweating

Determine current and voltage needed to operate system Determine data rate transfer of microprocessor

Finding correct digital converter and microcontroller

Finding correct code needed to convert it into useable data Determine Latency of code

Determine Analog Circuit Sensitivity Determine Analog Circuit Linearity Test flex sensors with the help of Dr. Debartolo

Variable bend points due to different sized hand

Test Plan Outline Test accuracy of sensors

Verify +/- degree error Test sensors ergonomics

Put on fingers and see if they restrict movement○ Too heavy, too big for fingers, etc..

Test if USB is enough power for the system or if a additional power source is neededPlug it into the microcontroller and see if it

works

Project Plan (Detailed Design)

Questions?