FEBRUARY 15 T H , 2013RIT MSDI

Detailed Design ReviewP13265 Motorcycle Safety Light Backpack System

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MSD Team

Primary Customers: Sport bike/standard riders who ride with backpacks

Surrogate Customers: Aaron League Andrew Nauss

Faculty Guides: Leo Farnand Vince Burolla

Industrial Design Consultant: Killian Castner

Team Members: Mike Baer, Project Manager Tyler Davis, Lead Engineer Ben Shelkey, ME Project Engineer TJ Binotto, EE Project Engineer Eric Dixon, EE Project Engineer

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Today’s Agenda

I. Overview 5 minutes, 1 slide

I. Project Description RecapII. Borrowed Motorcycle Specs

II. System Model Design 50 minutes, x slides

I. Family Tree, System OverviewII. System ComponentsIII. CAD Models/DrawingsIV. Component Assembly PlansV. Schematics, Pseudo-CodeVI. Bill of Materials

III. Feasibility Analysis, Prototyping, and Experimentation 30 mins, x slides

I. Testing for critical componentsIV. Test Plans 5 mins, x

slidesV. Next Steps 15 mins, x

slidesI. Updated Risk AssessmentII. MSDII Plan

VI. Conclusion, Comments 15 mins, x slides

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I. OVERVIEW

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Project Description Review

This project is intended to be prototype stage for marketable product for motorcyclists: Two major needs identified by motorcyclists:

1. Safety Hurt Report

Motorcyclist safety study performed by Henry Hurt, published in 1981 Of the accidents analyzed, ~75% of motorcycle accidents involved collision with

another vehicle “Failure of motorists to detect and recognize motorcycles in traffic is the

predominating cause of motorcycle accidents” Motorcycle Conspicuity Study

Riders wearing any reflective or fluorescent clothing had a 37% lower risk than other riders

Conclusion: “Increasing the use of reflective or fluorescent clothing, white or light coloured helmets, and daytime headlights…could considerably reduce motorcycle crash related injury and death.”

2. Electronics charging Most motorcyclists have no means of charging electronics

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Project Description Review

Conducted market survey regarding safety equipment and small electronics charging Currently at 77 participants (for results visit EDGE website)

Summary of target market (motorcyclists who): Often or always wear backpacks

Carry bulky items, such as books or laptops Ride in 4 seasons, and wet conditions (rain, fog, snow) Currently do not have method for charging electronics (such as

cell phone) Micro USB charging connection required

Believe visibility is important Utilize reflective surfaces, bright colors, and lighting systems

Would consider upgrading their existing lights to LED lights Place importance of aesthetics and durability of products

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Updated Engineering Specs

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Updated Engineering Specs

9Borrowed Motorcycle

• Type: 2006 Kawasaki Vulcan EN500• Owner: Andrew Nauss, 5th year ME

• Gave permission to test on bike and make small modifications, if necessary

• Not ideal type of bike for target market, but it shares same engine and electronics with the Ninja 500, a popular entry-level sport bike

Vulcan EN500

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II. SYSTEM MODEL DESIGN

Physical System OverviewBackpack

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Electronics Box Inside Bottom Backpack Compartment

Turn Signals

Brake/Running Lights

System Power Switch

Motorcycle Power Connector

User Control Panel On Chest Strap

Ambient Light Sensor

Physical System OverviewMotorcycle

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Transmitter Box

(Inside Box)Transmitter Board

w/ Xbee Transmitter

Bike Power In

Bike Light Signals In

Power Out

Wireless Light-Signals Out

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Family Tree (1/3)

Continued

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Family Tree (2/3)

From Backpack Assembly

Continued

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Family Tree (3/3)

From Backpack Assembly

Backpack Shell16

Shell Drawing

Shell Back

Shell Front

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Backpack Assembly

Shell

Cut and assemble main compartment zipper to length. Apply Liquid Nails to inside edges of top shell Attach and clamp fully zipped zipper to shell following the

instructions of the Liquid Nails Wait for glue to fully cure Safety pin unglued zipper side to soft backpack back Unzip zipper Sew second half of zipper to soft back Cut and assemble bottom compartment zipper to length Apply Liquid Nails to one connection corner of both shell halves Attach only the starting section the zipper following 3-4 Attach the rest of the zipper using non-permanent method. Using a paintmarker or sharpie make marks on shell/zipper in 1in

increments (these will be used to make sure zipper and shell are lined up properly when adhering).

Unzip sections Remove zipper from both sections and clean off non-permanent

adhesive Attach zippers halves to each shell section separately following 2-4. Unzip Apply Liquid Nails to back edge of bottom shell section. Attach and clamp bottom fabric backpack flap to back edge of shell

following 3-4. Attach quick access panel following 9-18.

LEDs

Drill Wire holes in all light strip slots. Place LED light strips in their appropriate slots with proper adhesive. For each light signal slot line lens ridge with silicone sealer. Press each lens into their appropriate slot. Wipe off any excess sealer and allow to dry

Electronics Pouch, Easy Access Pouch and Other

Place adhesive on edges of neoprene pouch. Press pouch into the top surface of the bottom backpack

compartment. Allow to dry. For easy access pouch follow 25-27; except the easy access

pouch will be attach on the inside perimeter of the easy access panel.

Drill hole on the bottom right side of shell in appropriate location for power switch.

Apply sealer to edge of hole. Pop power switch into hole and hold. Wipe off any excess sealer and allow to dry. Drill hole in the bottom of the shell for the power cord. Drill hole in specified location on top access panel for light

sensor. Place light sensor in through the shell. Apply sealant to back of the sensor to hold in place. Allow to dry. Disconnect chest strap clip from strap. Slide user control panel onto strap. Reconnect chest strap clip. Wire all components.

Battery Health Panel:

Press fit PCB into top panel Apply silicone sealer to back Fit back panel against the top Clamp and allow to dry for appropriate time

LightsSelection

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Lights: Compared thru-hole vs. flexible strips

Strips proved to be better for application

Colored LEDs documented to be more efficient than using white LED with colored lens cover

Strips available in .5m length w/ 30 LEDs/strip Can be cut into increments of 3 LEDs

Each 3 LED segment has necessary resistors to operate @ 12V

3 sets of High Intensity 30 LED SMD Strips 2 amber and 1 red $15/ strip, $45 total

*Note: 11 sections of red strips are needed, but only 10/ strip Will instead use one amber section, but will purchase 2nd red strip in MSDII if budget

allows

Flexible LED Strip

LightsFlash Functionality

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Lower Small Arrows

Dual Brightness Running/Brake Lights

Upper Small Arrows

Upper Large Arrows

2nd stage brake lights

1st stage brake lights

LightsRequirements

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Purchase:1 RED strip2 AMBER strips

*Note: Decision made to eliminate front shoulder strap lights due to installation complexity and marginal benefit to rider (headlight is much brighter)

Light CoversSelection

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Lens Covers: Provide protection from elements Clear thermoform acrylic sheets

Can bend to required shape Clear:

~92% Light Transmission @ 90 degrees incident to surface Red and Amber:

~9-15% Transmission @ 90 degrees Currently in discussion with manufacturer

Will be sending free samples of both clear and red Can hold off on purchasing until samples are received

Sheets will be cut to size and molded to sit flush with External ShellDiffusion Material:

Diffusion material is not necessary and will not be used Could potentially be added after completion of build

Clear acrylic

Electronics Housing22

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Electronics Housing Assembly

Components• Main Housing• Base (Aluminum)• Long side (on battery side,

straight, 2 holes tapped on top)• Long side (dividing board and

battery, has slot for wires)• Long side (battery side, has 5

holes (2x DB9, I USB 2x 2-in-1) and 2 holes tapped on top)

• 2x Short side (identical, each has slot in the top)

• Top piece• 4 screws• Glue

Assembly1. Use mill to dimension

pieces to specified dimensions

2. Create required holes (tapped and for plug)

3. Glue long sides and short sides to base as detailed in assembly drawing

4. Add board, with bushings underneath

5. Install board with screws

6. Install top with screws

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Transmitter Box24

• Original plans were to fabricate a custom-sized waterproof box for the transmitter

• Availability and competitive prices of prefabricated boxes outweigh the benefits of a custom box

• Selected box: HAMMOND Plastic Instrument Enclosures Black Project Box

Pictured: Bottom (facing up and down) Complete box

Price: $4.49 (free shipping)

Chest Strap User Control Panel25

Control Panel (Cover Off)

Control Panel (w/ Cover)

View of Attachment Loop

Hazard Button

Light Pattern Select

Brake/Turn Signal Function Toggle

Status LEDs

Status LED On/Off

Chest Strap User Control Panel26

Control Panel Top

Control Panel Bottom

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Cord Retraction

• In order to prevent the charging cable from being caught in the rear wheel if disconnected, a retraction system is necessary.

• Original plans resembled a retractable dog leash, but because of the size and stiffness of the wire this idea was abandoned.

• Rather than have the wire wind up, it will be an extendable coiled wire with the male and female ends being the connectors.

Quick-Connect Selection Criteria28

Must attach and detach both quickly and easily Must not shake loose Must have reasonable detaching pull force in order to prevent damage to other systems

(if rider forgets to unplug) Aesthetically pleasing Low production cost

3 = Good2 = Okay1 = Poor

Wire Connected to Buckle/Bayonet clip

Wire in Magnetic Housing

Laptop-Style Connection

Guitar-Style Connection

Quick to Attach (Preferable)

2 3 2 3

Will Release Automatically (Important)

1 3 3 3

Not Prone to Shaking Loose (Important)

3 3 2 2

Complexity 2 2 3 3Aesthetics 1 3 2 3Points 9 14 12 14Continue to cost analysis? no yes yes yes

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Cost analysis of Quick-Connect options29

Guitar Amp ConnectorPart cost $4.36Tax $0

(included)Shipping $1.37Total $5.73

Magnetic Housing style  

  Component

 Connector Plastic

Magnets

Part cost $7.98 $9.96 $3.00Tax $0.64 $0.80 $0.24Shipping $6.99 $5.00 $12.98Total (each piece) $15.60 $15.75 $16.22Total $47.58   

Laptop-style Connector

   Part cost $7.98Tax $0.64Shipping $6.99Total $15.60

Choice: Guitar Amp ConnectorReasons: -Quicker to attach because of no directional preference - “Clicks” in, less likely to come off accidentally

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System Block DiagramSystem Block Diagram BackpackElectronics Housing/PCB

Motorcycle System

Motorcycle Battery12VDC

Transmitter Housing/PCB

Quick Connect

12V->3.3V Regulation

Xbee Transmitter

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Transmitter Signals1. Headlight2. Left Turn Signal3. Right Turn

Signal4. Brake Light

AC/DC12VDC

System NiMH Battery12VDC

USB Charger

USB 2.0

5V12V

12V12V12V

XbeeReceiver

3.3V

Chest Strap PCB 12 LED Groups

Battery Monitor / Fuses

Battery Status LEDs

µCon (MSP430)

Voltage Regulation12V->5V5V->3.3V

12V

DarlingtonLight Drivers

Calibrate Button

User Interface Buttons

Chest Strap Signals1-4. Battery Status LEDs5. Function Toggle6. Function Toggle Sel7. Hazard8. 3.3V

12 4 63 5 7 8

2.5mm Connector

2.1mm Connector

Power Switch

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Battery SelectionTechnology

Re-evaluated initial selection of Li-Po battery due to safety concerns For scope of project, not possible to design box that is

guaranteed to prevent any damage to battery in event of crash

Li-Po and Li-Ion battery can catch on fire if cells are damaged, even with no current draw

Decided upon Ni-MH: They do not catch fire when damaged Still meet performance requirements Downside, heavier and larger volume

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Battery SelectionCriteria

Battery selection criteria: Meets minimum 12V voltage requirement (from lights) Meets minimum required power draw Meets maximum current draw (~3.5A worst-case) Can be connected to off-the-shelf AC smart charger

Built in overcharge protection and thermal monitoring

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Battery SelectionComparison

Three options Selection limited due to required capacity Selection further limited due to 12V requirement

Total price includes pack, charger Cost between 3 choices was negligible

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Battery SelectionComparison

After comparing in PUGH diagram, Powerizer Flat pack/charger was chosen due to flat size and larger capacity for the same price 4500 mAh, 12V, 4.2A max Dimensions: 7.2 x 2.9 x .8 inches Cost: $66, shipped 5 day lead time before shipping

Battery Health Monitor SelectionCriteria

Battery Health Monitor Criteria: Monitor voltage levels on NiMH Battery (14.5V-10.5V) Be able to load shed USB charging system at a

specific voltage. Shut off system as safe shutdown (10.5V) Send signals to Battery Status LEDs on chest strap

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Battery Health Monitor/Charging Circuit Function

Monitor Internal Battery Voltage Send Low Bat signal to µCon at desired level

Isolate Internal Battery from system under the following conditions. Low Battery Level Connected to: Wall Charger or Bike PowerBattery Voltage % Comments

14.5-13.5v 100-75%

13.5-12.5v 75-50%

12.5-11.5v 50-25%

11.5-10.5v 25-0%

10.5-10v 0% Isolate battery, and turn on indicator LED

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Battery Health Monitor DesignDesign

Compare the voltage on the supply to a reference voltage. Divide voltage supply level by 3. Use a 6.2V 1% precision Zener diode to set reference. Use voltage divider resistor string to set reference

voltage levels. 100% 75% 50% 25% 0% Comments

>13.5V

4.5V 4.52V

L L L L L

>12.5V

4.17V 4.19V

H L L L L

>11.5V

3.83V 3.85V

H H L L L

>10.5V

3.5V 3.52V

H H H L L

>10V 3.33V 3.35V

H H H H L System=OffIndicator=On

=10V 3.33V 3.35V

H H H H H Full-System=Off

Battery Monitor/Charging Schematic38

Comparators

Low-Battery Flag to µCon

1% PrecisionZener Diode

Power SupplySelection Criteria / Design

Power Supply selection criteria: Low power dissipation. Low heat generation. Regulate battery voltage to 5V for USB Charging

System Regulate battery voltage to 3.3V for µCon, Wireless,

User Interface switches and Battery Status LEDs.Power Supply Design

Vin >10V, 5V Switching Regulator, designed using Manu. Datasheet.

3.3V Linear Regulator using input from 5V Switching Reg.

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Power Supply Schematic40

5V Switching Regulator 3.3V Linear Regulator

USB Charger Selection Criteria /Design

USB Charger Selection criteria: Meet requirement of Standard USB Dedicated

Charging Port Maximize charging rate, while minimizing power/time.

USB Charger Design IC Solution for a Dedicated Charging port. 1A Charging Current

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USB Charger Schematic42

USB Enable from µCon

Dedicated Charging Port

Controller

Light Sensor SelectionCriteria

Light Sensor selection criteria: QSD124 NPN Silicon Phototransistor Narrow Reception Angle of 24DEG Power Dissipation is Max 100 mW

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Light Sensor Schematic44

LED Driver Selection

Drive a # of 3-LED segments requiring 200mA/segment.

Switch on/off using a µController input signal 0V->3.3V

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LED Driver Schematic46

Wireless Transmission SelectionCriteria

Xbee 802.15.4 Low-Power module w/ PCB Antenna Little configuration required for RF Communication Low-Power Consumption Low Input Voltage (3.3V) and Current (50mA)

requirements Small Physical Size Large amount of open-source documentation

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Transmitter (Tx) Board Schematic48

Voltage Regulation

Inputs

Transmitter Bike Signals

Microcontroller SelectionCriteria

Microcontroller selection criteria: Minimize controller power consumption. Maximize # of I/Os. Have PWM functionality.

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Microcontroller and Rx Schematic50

Xbee Receiver

Outputs to Light Drivers

µController w/ JTAG Prog.

Chest Strap System SelectionCriteria

Chest Strap criteria: House User Interface Switches House Battery Status LEDs Minimize Power Consumption Can be connected to off-the-shelf AC smart charger

Built in overcharge protection and thermal monitoring

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Chest Strap Schematic52

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Pseudo-Code (1/2)

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Pseudo-Code (2/2)

Continued from above

Overall Bill of Materials55

Overall Bill of Materials56

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High Cost Items

Battery- $66 w/shippingLights- $53 w/shippingMicrocontroller Dev. Kit - $29Xbee Units - $38PCBs- (3x$75) Shell Mold Fabrication- $135 w/shipping

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III. FEASIBILITY ANALYSIS, PROTOTYPING & EXPERIMENATION

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Light SystemLuminosity Test

• Three tests completed:• LED florescent tube strip (benchmark)• 4.4W 30 LED high power strip• 1.1 W 30 LED water resistant strip

• Tested high-brightness and weatherproof light strips in daylight

• Observed brightness ~100 ft away from light• All strips bright enough during day

Illuminated Light Strip*Note: Strip was much brighter than picture shows

Results: Lights bright enough for requirements

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Light SystemPower Consumption Calculations

Results: With very conservative estimate, in worst-case scenario, system should operate from battery for >2 hrs

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Bike Mock-UpTransmitter Box

1.75” 4”

1”

• A mock-up for transmitter placement was completed on donor bike

• Test-fit laptop charger into inner cover• Dimensions are 1.75 x 4 x 1 inch (H x L x W)

• Charger fit within cover with extra room• Transmitter box will be much smaller than charger => fits• Inner cover is protected from elements from outer cover (not

pictured)

Inner Cover

Charger

Results: Good location determined for Tx box

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Bike Mock-UpBike Battery Power Wire Routing

• Proper routing of the wire from the 12V bike battery is very important for several reasons:

• Mitigation of any risk that wire can catch on rider• If wire detaches, should not create safety risk (i.e. catch in

chain/wheel)• With wire attached, rider should be able to move freely• Rider should be able to easily attach wire

• Considered several routing options:• 1. In front of seat• 2. Rear of seat• 3. Side of seat

# 1

# 3# 2

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Bike Mock-UpBike Battery Power Wire Routing: Option 1

• Option 1 quickly eliminated due to routing over rider’s legs• Safety and rider discomfort issues

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Bike Mock-UpBike Battery Power Wire Routing: Option 2

• Option 2 is possible, but not ideal• Space under seat for wire to route without any stress

concerns• However, wire would have to route over seat, which could

blow around in wind and create greater risk of detachment

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Bike Mock-UpBike Battery Power Wire Routing: Option 3

• Option 3 presents best routing method• No interference with rider• No stresses/ methods for damage to wire• Shortest wire length of 3 options

Mock-up Wire Routed with Seat on

Space between frame and chrome

Results: Option 3 is best method

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Xbee Code

Configures the TX unit +++ -Grabs unit attention ATRE -Resets ATID 2286 -Sets address ATMY 1 -Sets my address to 1 ATD0 3 ATD1 3 ATD2 3 ATD3 3 -Sets DIO 0 through 3 to digital input ATDH 0 -Sets destination address high ATDL 2 -Sets destination address of receiver ATIR 14 -Sets sample rate to 20ms ATPR 0 -Disables internal pull-ups ATWR -Writes to memory

Configures the RX unit +++ -Grabs unit attention ATRE -Resets ATID 2286 -Sets address ATMY 2 -Sets my address to 2 ATD0 5 ATD1 5 ATD2 5 ATD3 5 -Sets DIO 0 through 3 to digital output ATIA 1 -Sets I/O input address to TX address ATWR -Writes to memory

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IV. TEST PLAN

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V. NEXT STEPS

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Updated Risk Assessment (1/3)

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Updated Risk Assessment (2/3)

6Multiple units cause interference.

Device does not function properly when multiple devices are in close proximity.

No design consideration for transmitting/receiving frequencies.

1 2 2Selected Xbee electronics technology that has large frequency range. Will pair devices at unique frequency.

Eric, TJ, Mike

7System doesn’t provide adequate light visibility.

No enhanced safety to other motorists.

Improper light selection luminosity and/or location. 1 3 3

Benchmarked existing light designs, purchased light strips and tested daylight visibility.

Eric, Mike, TJ

11Unsatisfactory appearance of product. Customer unhappy. No attention to aesthetics. 1 1 1

Consulted Industrial Design student, and conducted mock-ups of design concepts. Will receive feedback from customer on satisfactory design appearance.

Tyler

12Cannot find a motorcycle to modify.

No final deliverable. Untestable product.

Poor communication between team members. 2 3 6

Found donor motorcycle to add equipment to, and take preliminary test measurements on. Mike, All

13Device difficult to install on customer’s vehicle.

Reduced value of product to customer.

Poor consideration to interface with vehicle. 2 1 2

Took preliminary measurements on motorcycle, inspecting wires and least-intrusive method to modify. Will continue to reference customer vehicle throughout design process.

Mike, All

20Team mate(s) have to complete work assigned to others.

Team member(s) do more than fair share of work, reduction in overall quality of work.

Non-committed team member(s), not asking questions, agreeing to tasks but not following up.

2 3 6Poor peer reviews if expected work is not completed. Meetings with advisors. All

21Mold is unable to be manufactured

Desired backpack shell is unobtainable, reduced functionality in system.

Improper material selection, high manufacturing costs, no consideration for design for manufacturability

2 2 4Consultation with Brinkman lab specialists and/or ID students. Select materials while considering cost

Tyler

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Updated Risk Assessment (3/3)

22Bike light signals are too noisy

Inability/ limited ability for microcontroller to process signal wave form.

Noise from electronics on bike or environment, improper wire shielding, improper signal filtering

1 3 3 Proper wire selecting, proper signal filtering Eric

23Transmitter does not send proper signal to the backpack

Backpack lights do not function, or are not synced with bike. Improper wireless system coding 1 3 3 Test code and system functionality TJ

24Unable to completely sync with bike's brakes and turn signals

Backpack lights are not synced with bike, frequency mismatch between systems.

Incorrect edge detection sampling and timing within microcontroller

1 2 2 Test code and system functionality Eric

25PCB does not fit in the electronics housing

PCB is exposed to outside environment.

Dimensional mismatch between PCB and housing 1 3 3

Communication of dimensions between PCB designer and housing designer Ben

26Battery does not fit in the electronics housing

Battery is exposed to outside environment, cannot power system.

Dimensional mismatch between battery and housing 1 3 3

Communicated of battery dimensions to housing designer Ben

27Transmitter box does not fit in the decided location on the bike

Transmitter board is not properly housed, PCB is exposed to outside environment.

No investigation into on-board bike dimensions before transmitter housing design

1 3 3Took measurements on bike, presented maximum dimensions to housing designer Ben/Mike

28Power quick connector unable to disconnect in a crash scenario

Potential safety risk to rider.Poor consideration to quick connect design 1 3 3 Test quick connect release force requirements Ben

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Power quick connector disconnects do to wind, vibration, or other riding conditions

Potential safety risk to rider, backpack system no longer powered from bike.

Poor consideration to quick connect design 1 3 3

Test quick connect system on bike at maximum required speed Ben

30Backpack assembly falls apart during testing

Electronics, lights, or shell are damaged.

Poor attachment/adhesion of zippers or shell 2 3 6

Proper selection of adhesive. Consideration of manufacturing methods. Tyler

31 Random act of GodSubsystems destroyed beyond repair. Unpredictable disaster 1 3 3 Store components in secure location All

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MSD II Plan- Overview

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MSD II Plan- Overview

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MSD II Plan- 4 week plan

• End Week 1• Complete Final Assembly and Test Plans- All

• End Week 2• Completed Assembly of Transmitter Housing- Ben• Completed Assembly of Transmitter Board- TJ• Completed Debugging of Transmitter Housing- TJ

• End Week 3• Completed Assembly of In-bag Electronics Assembly- Ben• Completed In-bag Assembly Board- Eric/TJ• Completed Backpack External Shell- Tyler/Mike• Completed DC Quick Connect Assembly- Ben

• End Week 4• Completed Backpack Shell Integration w/Soft Shell- Tyler• Completed Light/Light Cover Integration w/Shell- Mike/Tyler• Completed Debugging of In-Bag Assembly- Eric/ TJ

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VI. CONCLUSION, COMMENTS

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Questions