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: Promote community awareness of electric vehicles 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 The Racing Electric Vehicle, or R.E.V., is an electric car designed to compete in the 2007 Formula Hybrid competition. This competition is for IEEE student members to redesign, modify, and compete with hybrid Formula SAE racing cars. The students are encouraged to make use of previous years Formula SAE cars so that the knowledge, creativity, and imagination of the students are challenged. The cars are built with a team effort over a period of about one year and are taken to the annual competition for judging and comparison with other modified Formula SAE vehicles from colleges and university throughout the United States. The end result is a great experience for aspiring engineers in a meaningful project as well as the opportunity of working in a dedicated team effort. The R.E.V. team will design, manufacture, assemble, test, and present their electric car in the 2007 Formula Hybrid 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

Driver Interface & Ergonomics Team Organization: Team Lead Design Teams Development Group Procurement Group Manufacturing Group Integration Team Chassis & Body Chassis Redesign Body Redesign Mounting Points Aeros/Ground Effects Drive System Motor Drivetrain Control System Battery System Cooling System Shielding System Electrical Battery Management Instrumentation Data Transfer System Power Management Vehicle Dynamics Suspension System Steering System Braking System Driver Interface & Ergonomics Cockpit Design Safety Equipment Driver Interface

Team Organization: REV Design Teams Team Lead: Elizabeth Diaz Design Teams Drive System Team: Vehicle Dynamics Team: Chassis & Body Team: Josh Wales AJ Nick Kathy Murray Jason Miner AJ Nick Dave Wickers Jason Miner Dave Wickers AJ Nick Jared Doescher Kathy Murray Electrical Team: Driver Interface Team: Matt Reedy Valerie Bastien Audrey Moyers Kristi Harrell Oliver Zimmerman Dave Wickers

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)

Engineering Specifications 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 UPDATE, and is this the original set of objectives? 9

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 UPDATE, and is this the original set of objectives? 10

Static Stress Analysis Max deflection: -.0098 inches 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 Pro-e drawings, or calculations that were done 14

Lessons Learned: Chassis Have more than one designer on the chassis Design and analysis together Consideration of weight versus strength Pro-e drawings, or calculations that were done 15

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

Front Suspension BELLCRANK POSITION CHANGE FOR CLEARANCE ISSUES Pro-e drawings, or calculations that were done BELLCRANK POSITION CHANGE FOR CLEARANCE ISSUES

Rear Suspension COILOVER ACTUATION DESIGN COILOVER ACTUATION BUILD Here we want something about the design specs of the suspension COILOVER ACTUATION BUILD

Suspension Adjustability Roll Center Shims between clevis

Suspension Spring Rates Any other info about the suspension FRONT SPRING RATE ≈ 350 LB/IN REAR SPRING RATE ≈ 372 LB/IN

Adjustable damping in jounce and rebound Preload adjustment Dampers Nitrogen Charged Adjustable damping in jounce and rebound Preload adjustment Cost effective Jupiter 5 by Risse Racing

Full Ackermann geometry Steering Geometry Rack and Pinion Lower rear placement Full Ackermann geometry Any other info about the suspension

Testing and Improvements Final car setup and fine tuning Ride Height Camber Toe Add anti-roll bars Add sensors Pro-e drawings, or calculations that were done

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 General information about the differential, why it was chosen, what specs it helped to fulfill

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 Not sure if we want to use a set up like this with pro-e and ansys on one slide or leave it like before separated

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 Something on here about motor choice

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) Nomex fabric on walls and bottom for electrical insulation and fire protection Odyssey Battery, Model PC680

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 Fuse Albright SW200 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) Something on here about motor choice

Design: Brakes Design Criteria Alterations in Design 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 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 Current Design

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 increase reliability More ergonomic for driver Current Design

Design: Safety Design Criteria How we meet/exceed 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

Emergency Stop Switches Design: Safety Main Switch Safety Harness Emergency Stop Switches Hairball – Controller Interface Safety Suit & Helmet

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) Something on here about motor choice

Design Changes: Body Recommendations 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 Car ran week after spring break

Performance Tests: Acceleration & Braking Completed Testing Results 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 the pedal systems Completed Testing Results Max Speed of 67 mph Test completed within 0.1 mile

Performance Tests: Autocross Completed Testing Results 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 know how the steering will handle Completed Testing Results Slalom runs completed to test the suspension and steering Resulted in sheered grade 2 bolts, all bolts replaced with grade 8 bolts

Performance Tests: Endurance Completed Testing Results 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 during the halfway point of the endurance race at competition Completed Testing Results Time lasted : 20 minutes at 10 mph Resolution: larger controller and more batteries

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 $76 Potentiometer $700 Differential $1,440 Lead Acid Batteries $2,860 Controller $1,600 DC Motor Chromoly Tubing $86 Spherical Bearings $460 Brakes $160 Tires $680 Chromoly Tubing $740 Fiberglass $80 Shielding $180 Nomex Miscellaneous $250 Battery Management PLC and Touch Screen Driver Interface PC Boards $150 00 Guage Wire $80 Master Switch $155 Contactor $240 Fuses $66 Miscellaneous $300 Ooop forgot about this one, going to change it out to the other budget PLC and Modules $286 Touch Screen $810 Speed Sensor $55 Safety Harness $180 Driver Accessories $430 Miscellaneous $200

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

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 Steering pinion gear Seat Wheel Brakes Recycling of components Cost saving time savings Analysis Production Implementation

Keep the car fully electric Run true performance tests 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 BS about the specs for integration, something that will not interfere with either system, but will satisfy the needs of both the mechanical and electrical specifications

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?!?