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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: [email protected] 585-317-3595 Secondary Customer: Susan Farnard
Contact: [email protected] 585-475-4567 Faculty Guide: Ed Hanzlik
Contact: [email protected] 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?