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					     FLORIDA INSTITUTE OF TECHNOLOGY
         COLLEGE OF ENGINEERING




                         Design Presentation
                        Project: 2007 R.E.V. Team

                                Presented By:

   Elizabeth Diaz      Jason Miner              Jared Doescher      Josh Wales
Kathy Murray        AJ Nick             Dave Wickers             Oliver Zimmerman
                           Project Scope:

• Design and Build an electric racing vehicle

• Promote community awareness of electric vehicles

•Electric Car designed to compete in SCCA Autocross
        and Formula Hybrid competition

       - Competing as “Hybrid-in-Progress” vehicle for
             one year only

       - Electric Car designed to compete in Autocross,
                Acceleration and Endurance races

•Will meet requirements for the 2007 Formula Hybrid
        competition and NEDRA race competition
                   Engineering Objectives:


• Acceleration from 0 to 60 mph in under 5 seconds

• Top speed of 80 mph

• Maximum power available between 20 and 40 mph

• Lightweight (under 650lb without driver)

• 15 minute battery life for continuous draw
                                                Team Organization:

                                                           Team Lead



                        Development Group            Procurement Group              Manufacturing Group



                                                       Integration Team



                                                          Design Teams



 Chassis & Body           Vehicle Dynamics      Driver Interface & Ergonomics    Drive System         Electrical

Chassis Redesign         Suspension System   Cockpit Design                  Motor              Battery Management
Body Redesign            Steering System     Safety Equipment                Drivetrain         Instrumentation
Mounting Points          Braking System      Driver Interface                Control System     Data Transfer System
Aeros/Ground Effects                                                           Battery System     Power Management
                                                                                Cooling System
                                                                                Shielding System
               Team Organization: REV Design Teams
                          Team Lead:
                        Elizabeth Diaz
  Design Teams

Drive System Team:   Vehicle Dynamics Team:   Chassis & Body Team:

Josh Wales           Jason Miner              Jason Miner
AJ Nick              AJ Nick                  Dave Wickers
Kathy Murray         Dave Wickers             AJ Nick
                                              Jared Doescher
                                              Kathy Murray

 Electrical Team:    Driver Interface Team:
Matt Reedy           Oliver Zimmerman
Valerie Bastien      Dave Wickers
Audrey Moyers
Kristi Harrell
                     Major Goals of the Team


• Complete the car

• Create/Integrate Lithium-Ion pack

• More publicity
  – Autocross racing
  – More EV events
  – Local advertising

• Funding
                            Florida Tech REV




• Overall Length, Width, Height:
  107in x 60in x 46in
• Wheelbase: 68.5in
• Front Track: 52in
• Rear Track: 50in
• Weight: 795lbs (without driver)
                            Design: Chassis

             Engineering Specifications
• Static deflection – Less than .333”
• Torsional Rigidity – above -1500 ft-lbs/deg
• Wheelbase – between 60” and 70”
• Designed to fit 95 percentile person
• Withstand stresses under dynamic and static loading
  with factor of safety of 3
                           Design: Chassis



• Side Pods act as impact structure
• Upper side impact structure
  member attached too high to main
  hoop
• As requested by Formula Hybrid,
  new cross member had to be
  constructed to protect driver
                                Static Analysis

    Deflection Analysis                 Static Stress Analysis




Max deflection: -.0098 inches           Max stress: 5361 psi
                                        Factor of safety:11.9
               Dynamic Stress Analysis

     • Using MSC ADAMS to get forces at A-Arm attachments
                     •Braking ( 60- 0 in 3 sec)
                     •Lane change at 50 mph
                 •60 mph radius turn of 343 feet
              •Applied loads in ANSYS to find stress

     Braking                                  Cornering




Max stress: 22126 psi                   Max stress: 16159 psi
Analysis Changes: Chassis
Torsional Rigidity Analysis



                              •Constrained back of
                                 frame and added
                               forces to front hoop
                              •Measured deflection
                                at nodes on hoop
                              •Calculated Torsional
                                    rigidity by:




                               4900 ft/lbs per degree
                 Manufacturing: Chassis

• Frame was constructed on campus
• Weld analysis proved welds will hold
• Intersections with many multiple welds were
  hardest to cope
               Lessons Learned: Chassis


• Have more than one designer
  on the chassis
• Design and analysis together
• Consideration of weight
  versus strength
                        Suspension Design


• Allow 1” travel jounce and rebound
• Achieve maximum tire contact at all times
• Optimize handling

  • Non-equal, Non-parallel A-arms
  • Push rod actuated coil-overs
  • Variable dampers
                    Suspension Design Specifications

Table 3.7: Front Suspension Geometry           Table 3.8: Rear Suspension Geometry
              Static Camber            -1.5˚                  Static Camber           0˚
      Camber Gain in Jounce       -.95˚/1"           Camber Gain in Jounce      -1.05˚/1"
   Camber Gain in Rebound          .89˚/1"         Camber Gain in Rebound       1.02˚/1"
                      Caster            5˚                           Caster           3˚
             Kingpin Offset        .915"                     Kingpin Offset          0.02"
         Kingpin Inclination            0˚               Kingpin Inclination          0˚
                      Toe In            0˚                           Toe In           1˚
          Ground Clearance              2"                Ground Clearance            2"
           Static Roll Center      1.23"                  Static Roll Center         1.34"
    Roll Center @ 1" Jounce        -.18"            Roll Center @ 1" Jounce          0.4"
  Roll Center @ 1" Rebound         2.65"          Roll Center @ 1" Rebound           2.75"
          Front Track Width            52"                Rear Track Width           50"
                   Front Suspension




BELLCRANK POSITION CHANGE FOR CLEARANCE ISSUES
                       Rear Suspension


                           COILOVER ACTUATION DESIGN




COILOVER ACTUATION BUILD
Suspension Adjustability




                 Shims between clevis




   Roll Center
                    Suspension Spring Rates




FRONT SPRING RATE ≈ 350 LB/IN   REAR SPRING RATE ≈ 372 LB/IN
                                Dampers



•    Nitrogen Charged
•    Adjustable damping in jounce and rebound
•    Preload adjustment
•    Cost effective


    Jupiter 5 by Risse Racing
                  Steering Geometry

• Rack and Pinion
• Lower rear placement
• Full Ackermann geometry
                   Testing and Improvements

• Final car setup and fine tuning
   – Ride Height
   – Camber
   – Toe

• Add anti-roll bars
• Add sensors
              Lessons Learned: Suspension


• Check more thoroughly for clearance issues
• Use proper bolts
• Change clevis design
Design: Differential




    • Brute Force Kawasaki ATV
      front differential
    • Limited Slip with a selectable
      locker
    • 4.375 gear reduction
                                 Differential & Mounting


•Tensile Yield Stress of Aluminum: 47000 psi
•3/8” thick aluminum
     •Max Von Mises stress: 33665 psi
     •Factor of safety of 1.3
                            Differential & Mounting


•Instead of remanufacturing with 1/2”
aluminum an additional mount was
added
•Max Von Mises stress: 25944 psi
•Factor of Safety of 1.8
              Design: Electrical Integration

• Warp 9” motor, 80hp peak, 140ft-lbs
• 32.3 continuous horsepower (versatile)
• 600amps, 144volts from Zilla 1K-HV (with power
  conversion)
• 2 min full throttle run time, 15min at 35mph
• Top Speed 85mph @ 6000 rpm
• Pic to PLC to LCD
                  Power Source & Containment Area

                               • Lead Acid Batteries 232lbs, 13.6
                                 usable Ah (17ah, up to 80%
                                 discharge) at 192V (Nominal)
                               • 16 cells, cost approx. $1500
                               • Odyssey PC680 Lead-acid batteries


• Diagonal Support tube thickness
increased to .095” (full X)
• Battery Layout
    Strapped together then strapped to
    supports
    Plexiglas to cover connections (with
    High Voltage Warning Label)
                                                      Odyssey Battery,
    Nomex fabric on walls and bottom for
                                                       Model PC680
    electrical insulation and fire protection
            Power Source & Containment Area


        • Full High Voltage Accumulator
        Containment
             Dual Contactors default to Open
             3 Emergency Stop Buttons
             Fuse Backup
             High power lines outside Battery Area
            held in rubberized conduit




Ferraz-Shawmut                            Albright SW200
     Fuse                                    contactor
                   Design: Performance Calcs

• Motor, Battery, gear ratio combination was essential
  decision.
• Excel Spreadsheet used to compare and optimize.
• Takes into account specs and calculates 0-60 time,
  voltage drop, runtime, and more.
• Final Configuration:
  0-60mph in 4.5 seconds (calculated)
                          Design: Brakes


• Design Criteria
  – Braking system that acts
    on all four wheels and is
    operated by single control
  – Two independent
    hydraulic circuits
• Alterations in Design
  – New master cylinders
    were purchased due to a
    leak in the old ones
                             Design: Brakes


• Design Calculations
  – To optimize handling the front
    wheels should lock up first in a
    full braking situation
     • To ensure this a bias was applied
       to master cylinders
         – Front 60% and rear 40%
  – Full Braking from 60 mph
     • Calculated stopping distance:
       124.73 ft
                 Design Changes: Steering Wheel
                                                        Previous Design

• Design Criteria
   – Must be able to hold the touch
     screen
   – Comply with SAE rules
   – Designed to be as light as
     possible while remaining rigid
     enough to protect touch screen    Current Design

   – Shaped for driver’s comfort
• Alterations in Design
   – Changed because of the
     method of mounting provided
     from manufacturer
   – Created a new wheel to be fully
     closed loop IAW SAE rules
               Design Changes: Steering Wheel


• Design Criteria
   – Structurally Rigid and
     Reliable
• Previous Steering Wheel
  did not fit design criteria
   – Also did not need touch
     screen for competition
            Design Changes: Acceleration Pedal
                                       Previous Design

• Design Criteria
  – Ergonomic to fit driver
  – Highly reliable
• Alterations in Design
  – Design Simplified to        Current Design
    increase reliability
  – More ergonomic for driver
                                Design: Safety

• Design Criteria
   –   Must have a 5-point or 6-point harness
   –   Driver Must Be Isolated from High-voltage
   –   Front Impact attenuator
   –   Side impact structure
   –   Must have at least 3 Large Emergency Shut Off buttons
• How we meet/exceed criteria
   – We have a 5-point harness that corresponds to Formula SAE
     regulations
   – High-voltage wires are isolated in Side Pods and conduit outside
     of Side Pods
   – Impact attenuator fits FSAE regulations
   – Our Side Impact structure Approved Structural Equivalency
   – Two Emergency Shut off buttons on either side of roll hoop and
     one on driver’s dash board, also one main switch
   – Hairball Controller Interface allows user to limit power
                             Design: Safety




                                                   Main Switch
   Safety Harness




                       Emergency Stop Switches




                           Hairball – Controller
Safety Suit & Helmet                   Interface
                 Design: Impact Attenuator

•   HRH-10/OX – 3/16 – 4.0 HexWeb Honeycomb
•   7 – 1” layers separated by steel sheet
•   650psi Typical Stabilized Strength
•   Designed to absorb K.E. of 945lb, 15mph car &
    driver at less than 20G’s (capable of stopping
    greater mass than required by Formula Hybrid)
                            Design Changes: Body


• Body covers from front tip back to
  the main roll bar
• Side Pods fully enclosed
• Molded body to fit over front
  shocks and allow room for the
  impact attenuator
• Floor and side panels around the
  motor to protect the motor from
  debris

• Recommendations
    – Start Early
    – More than one committed
      person involved
                          Performance Testing


• Testing has been done for
  several different aspects of
  the car
   – Acceleration
   – Autocross
   – Endurance
• Testing still needs to be
  completed for
   – Braking
• Testing is also serving the
  purpose of acquainting the
  drivers with the handling of
  the car
                     Performance Tests:
                    Acceleration & Braking


• Tests were preformed
  to see if the car can
  reach the design
  specifications set with
  the higher weight
• These tests allow the
  drivers to learn the
  sensitivities of each of    Completed Testing Results
                             • Max Speed of 67 mph
  the pedal systems          • Test completed within 0.1 mile
               Performance Tests: Autocross



• This testing is used to
  demonstrate that the car
  can fulfill the turning
  radius requirements that
  have been set
• Autocross testing is also
  used so that the drivers          Completed Testing Results
  know how the steering       • Slalom runs completed to test the
                              suspension and steering
  will handle                 • Resulted in sheered grade 2 bolts,
                              all bolts replaced with grade 8 bolts
                  Performance Tests: Endurance



• The endurance testing
  serves the purpose of
  finding out how long the
  batteries will last under
  constant draw

• This section of the testing
  will also allow the team to
  find out how long it will take
  to charge the batteries                Completed Testing Results
                                   • Time lasted : 20 minutes at 10 mph
  during the halfway point of
                                   • Resolution: larger controller and more
  the endurance race at            batteries
  competition
                           Testing: Conclusions


• The testing that has been performed on the car has
  shown that we meet the design specifications for
   – Turning Radius
   – Maximum power available between 20 and 40 mph
• We do not meet the requirements for
   – Lightweight (under 650lbs with driver)
• We expect to meet, but have not yet tested
   – Acceleration from 0 to 60 mph in under 5 seconds (4.5seconds –
     calculated)
   – Top speed of 80 mph (85mph - calculated)
   – 15 minute battery life (at constant speed of 35mph)
                     Project Management:


Primary functions
• Budgeting
• Funding/Sponsors
• Scheduling
• Managing a Team
• Assigning Tasks
                                                  Budget:
                                        Budget
                                        $13,265


     Drive System                 Vehicle Dynamics            Chassis and Body
DC Motor              $1,600    Chromoly Tubing      $86    Chromoly Tubing      $740
Controller            $2,860    Spherical Bearings   $460   Fiberglass           $80
Lead Acid Batteries   $1,440    Brakes               $160   Shielding            $180
Potentiometer         $76       Tires                $680   Nomex                $80
Differential          $700                                  Miscellaneous        $250

Battery Management             PLC and Touch Screen             Driver Interface
PC Boards             $150     PLC and Modules       $286   Safety Harness       $180
00 Guage Wire         $80      Touch Screen          $810   Driver Accessories   $430
Master Switch         $155     Speed Sensor          $55    Miscellaneous        $200
Contactor             $240
Fuses                 $66
Miscellaneous         $300
                                       Resources:


                             Resources


       Sponsors:           Programs:                          Personnel:
•USA                •Pro/Engineer Wildfire 3.0   •Dr. Larochelle – Team Advisor
•Grassroots EV      •ANSYS                       •Dr. Grossman – Team Advisor
•US Didactic        •ADAMS                       •Larry Buist – Electrical Support
•Charles Whalen     •OrCAD                       •Bill Bailey – Shop Supervisor/Welder
(FLEAA)
                    •EZ Touch – EZ Panel         •John Amero – Machinist
•Bob Steele Chevy   Enhanced
                                                 •Bill Battin – Technical Support
•FLEAA              •EZ PLC Editor
                                                 •Stephanie Hopper – Lab Director
•CV Restoration     •LabView
                                                 •Frank Leslie – Public Relations/EV
•C2 Design          •PIC Basic                   Advisor
• Brevard Rentals
                         Recommendations:


• Scheduling
    Design completion
    Give ample time for testing
• Managing a Team
   • Set goals high
   • Keep the team going but give some time to relax
• Assigning Tasks
   • Don’t overload one person to a task
   • Assign tasks to the appropriate person
              Lessons Learned

• Interdisciplinary cooperation
     - Start early with incorporation of electrical
     systems
     - Stay in communication
     - Introduce each other systems to the other group
• Leave enough time for testing and troubleshooting
• Keep drawings updated as soon as something
changes
                     Lessons Learned


                             Examples
Recycling of components
                             -Rims
-Cost saving
                             -Shocks
-time savings
                             -Steering pinion gear
    -Analysis
                             -Seat
    -Production
                             -Wheel Brakes
    -Implementation
                      Recommendations:



Suspension:
• Anti-roll bars
• Data Logging



            • Keep the car fully electric
            • Run true performance tests
            • Keep electrical engineers on the team
                       Future Improvements


• To Do:
  –   Build Battery Management System
  –   Check and Adjust Differential Mounting
  –   Improve Real World Motor Performance
  –   Locate Li-Ion/Li-Polymer Sponsor
  –   Evaluate BMS (Battery
      Management Systems) options
                       Future Improvements


For Future REV Form
• Schedule testing time on a real track
• Reintroduce Lithium Ion batteries as power source
• Reincorporate PLC control system
• Expand on sensors
         - Temp, speed
         - efficiency
• Increase Data collection for evaluation of performance
                       Future Improvements



For Future Formula Hybrid
-Use IC as power generator
-Use electric engine for propulsion
-Reconsider Capacitors for rapid charging and discharging cycles
-Redesign frame to fit all components
Questions?!?

				
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