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` a “BMW1025
`
`Page 1 of 20
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`BMW1025
`Page 1 of 20
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`

`

`BMW1025
`Page 2 of 20
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`BMW1025
`Page 2 of 20
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`

`

`1997 FutureCar
`Challenge
`
`SP-1359
`
`GLOBAL MOBILITY OATABI\SE
`All SAE papers, standards, and selected
`books are abstracted and indexed in the
`Global Mobility Database
`
`Published by:
`Society of Automotive Engineers, Inc.
`400 Commonwealth·Drive
`Warrendale, PA 15096-0001
`USA
`Phone: (724 )" 776-4841
`Fax: (724) 776-5760
`February 1998
`
`BMW1025
`Page 3 of 20
`
`

`

`Permission to photocopy for internal or personal use of specific clients, is granted by SAE
`for libraries and other users registered with the Copyright Clearance Center (CCC), pro(cid:173)
`vided that the base fee of $7.00 per article is paid directly to CCC, 222 Rosewood Drive,
`Danvers, MA 01923. Special requests should be addressed to the SAE Publications
`Group. 0-7680-0179-X/98$7.00.
`
`Any part of this publication authored solely by one or
`more U.S. Government employees in the course of their
`employment is considered to be in the public domain,
`and is not subject to this copyright.
`
`No part of this publication may be reproduced in any form, in an electronic retrieval sys(cid:173)
`tem or otherwise, without the prior written permission of the publisher.
`
`ISBN 0-7680-0179-X
`SAE/S P-98/1359
`Library of Congress Catalog Card Number: 97-81274
`Copyright© 1998 Society of Automotive Engineers, Inc.
`
`Positions and opinions advanced in this
`paper are those of the author(s) and not
`necessarily those of SAE. The author is
`solely responsible for the content of the
`paper. A process is available by which
`the discussions will be printed with the
`paper if is is published in SAE Transac(cid:173)
`tions. For permission to publish this paper
`in full or in part, contact the SAE Publica(cid:173)
`tions Group.
`
`Persons wishing to submit papers to be
`considered for presentation or publication
`through SAE should send the manuscript
`or a 300 word abstract to: Secretary,
`Engineering Meetings Board, SAE.
`
`Printed in USA
`
`BMW1025
`Page 4 of 20
`
`

`

`PREFACE
`
`The papers in this Special Publication, 1997 FutureCar Challenge (SP-1359), were
`originally written to fulfill competition requirements from the 1997 FutureCar
`Challenge. These papers document the design, construction, and performance of ten
`advanced technology vehicles, which represent the second year of the FutureCar
`Challenge sponsored by the U.S. Department of Energy and the U.S. Council on
`Automotive Research (Chrysler, Ford, and General Motors). The sponsors invited
`these universities to use the most advanced vehicle technologies available to them to
`modify a mid-size vehicle that approaches 80 miles per gallon (mpg) while still
`offering the same comfort, safety, and affordability that consumers expect from
`conventional vehicles. The goals of the competition mirror those set by the
`Partnership for a New Generation of Vehicle program, a cooperative effort between
`the federal government and the domestic automobile industry.
`
`Beginning with a conventional Lumina, Intrepid, or Taurus, each university team
`made whatever modifications were necessary within the constraints of the existing
`vehicle to approach 80 mpg. Most teams made dramatic changes to the powertrain,
`added energy storage capability, improved aerodynamics, and attempted to reduce
`vehicle weight. Safety, energy efficiency, improved emissions characteristics,
`affordability, and the use of advanced technologies are the cornerstones of the
`FutureCar Challenge. These vehicles represent some of the most innovative
`advanced technology vehicles ever attempted . The technical reports that were a
`scored event in this competition are presented in this volume to record design
`rationale, engineering features, and performance of these unique vehicles. The
`vehicle's technical specifications and performance summary from the competition are
`shown in Table A; the results summary is shown in Table B.
`
`These teams competed in a series of dynamic and static events at the GM Technical
`Cent~r in Warren, Michigan. Emissions testing and fuel economy assessment took
`place at the U.S. Environmental Protection Agency National Vehicle and Fuel
`Laboratory in Ann Arbor, Michigan. The teams then embarked on an over-the-road
`endurance event from Warren to Washington, DC, where they participated in a
`vehicle display and awards ceremony on Capitol Hill.
`
`The papers in this publication cannot fully convey the dedication and considerable
`effort demonstrated by the students and faculty to design and build not only an
`advanced car, but a concept for a new generation of vehicles. On behalf of all the
`participants and organizers of these competitions, we extend many thanks to those
`companies that made these competitions possible through financial contributions, in(cid:173)
`kind support, and the dedication of their staffs.
`
`Key Sponsors of the 1997 FutureCar Challenge included the U.S. Department of
`Energy, United States Council for Automotive Research, Chrysler Corporation, Ford,
`and General Motors. Other sponsors included the U.S. Environmental Protection
`
`BMW1025
`Page 5 of 20
`
`

`

`Agency, Allied-Signal Automotive, Natural Resources Canada, Detroit Edison, and
`National Science Foundation. Acknowledgments go to the American Society for
`Engineering Education and the Center for Transportation Research at Argonne
`National Laboratory for organizing the competition.
`
`Shelley Launey
`Office of Advanced Automotive Technologies
`U.S. Department of Energy
`
`BMW1025
`Page 6 of 20
`
`

`

`School Name
`
`Virginia Tech
`
`l\lodel
`
`Lumina
`
`Com:ordi~ Uni,·ersiLy
`
`lmrepid
`
`Wes1 Vi rginia University
`
`Lumina
`
`Lawrence Tech
`Univ. of Mich iga,,, Ann
`Arbor
`
`Taurus
`
`Taurus
`
`Un iv. of Cal ifornia, Davis
`
`Taurus
`
`Michigan Tech
`
`Intrepid
`
`Univers ity of Maryland
`
`Intrepid
`
`Table A. 1997 FutureCar Challenge Technical Specifications and Performance Summary Sheet
`Vehicle
`Weight
`(lb) Powertra in Fuel
`
`Engine
`
`Suzuki
`
`Electric
`Pea k
`Size (cc) Power Motor
`General
`Electric
`
`1000
`
`41 kW
`
`Diesel Volkswagen
`
`)900
`
`Saturn
`
`1900
`
`Diesel Volkswagen
`
`1900
`
`65 kW
`
`Solectria
`Unique
`12'1 hp Mobility
`Unique
`67 kW Mobility
`
`8 5 kW
`
`Peak
`Power Battery
`Hawker
`Energy
`Hawker
`22 kW Genesi.s
`Hawker
`55 Kw Genesis
`Ovonics
`64 kW Banery
`
`Pack
`Voltage
`
`336
`
`155
`
`180
`
`171
`
`120
`
`172
`
`312
`
`324
`
`Capacity
`(A-hr)
`
`Power
`Generator Rating
`Fisher
`4.0 kWh for c/2 Technology 20kW
`
`Battery
`Charger
`Hughes Magne
`Charge
`
`46 Ahr for c/20
`
`NIA
`Unique
`4.2 kWh for c/2 Mobility
`I 6.25 kWh for
`cl20
`
`NIA
`
`NIA
`
`3.8 kWh for c/2
`16.6 kWh for
`c/20
`
`NIA
`Fisher
`3.6 kWh for cl2 Electronics
`Northrop
`7.1 kWh forcl2 Grumman
`
`NIA
`
`NIA
`
`Hobart
`Lockheed
`Manin
`
`Zivan
`Hughes Magne
`Charge
`Hughes Magne
`Charge
`
`18kW
`
`N/A
`
`NIA
`
`NIA
`
`24 kW
`
`17kW
`
`4050 Series HEV Propane
`Parallel
`HEV
`
`3871
`
`4 114 Series HEV CNG
`Parallel
`HEV
`Parallel
`HEV
`Parallel
`HEV
`
`3828
`
`377 1
`
`3348
`
`3688 Series HEV RFG
`
`Diesel Volkswagen
`Honda
`Today
`Mercury
`Marine
`
`RFG
`
`1900
`
`6 5 kW
`
`22 kW
`
`660
`
`500
`
`53 kW
`
`Suzuki
`
`1000
`
`BMW
`
`1100
`
`SAFT
`Fisher
`Ovonics
`Unique
`48 kW Banery
`36 kW Mobility
`Hawker
`Unique
`Energy
`22 kW Mobility
`Hawker
`Northrop
`41 kW Grumman 98.5 kW Energy
`Unique
`Hawker
`61 kW Mobility
`Energy
`Hawker
`Energy
`
`66 kW
`
`Baldor
`
`35 kW
`
`74 kW
`
`3952 Serles HEV E85
`Parallel
`HEV
`Parallel
`HEV
`
`RFG
`
`Diesel Volkswagen
`
`1900
`
`3726
`
`3709
`
`3456 Non-HEV CNG
`Parallel
`HEV
`
`3238
`
`Daihatsu
`
`850
`
`71 hp
`
`NIA
`
`NIA
`
`NIA
`Hawker
`66kW Kollmorgen 20kW Energy
`
`B-20 Volkswagen
`
`1900
`
`CA State Univ., Northridge
`Univ. ofWisconsin,
`Madison
`
`Lumina
`
`Intrepid
`
`Univ, of Illinois, Chicago
`
`Taurus
`
`Ohio State University
`
`Lumina
`
`Faculty Adviso r
`/Phone
`Doug Nelson
`540/231-4324
`Dr. Henry Hong
`5 I 41848-3154
`Chris Atkinson
`3041293-41 11
`Nick Brancik
`8101204-2567
`Valdis Leipa
`31 3n47-3625
`Andrew Frank
`916ns2-s 120
`Carl Anderson
`9061487-3020
`David Holloway
`301/405-5259
`Dr. Tim Fox
`8181885-2197
`W. Milestone
`6081262-3204
`M. Y Choi
`312/996-5 l 50
`Dr. Rizzoni
`614/292-3331
`
`300
`
`333
`
`NIA
`
`. 312
`
`7.2 kW for c/3
`
`NIA
`
`2.8 kWh for c/2
`
`NIA
`
`NIA
`
`NIA
`
`NIA
`.84 kWh for
`c/20
`
`NIA
`
`NIA
`
`Kollmorgen 20kW
`
`NIA
`Hughes Magne
`Charge
`
`NIA
`
`NIA
`NIA, Charge
`Sustaining
`
`Energy Efficiency
`
`Highway
`Ci1y
`(l\lPGE)
`SOC ~lethod lMPGE) SOC Mt1hod
`School N•ni•
`38.98
`Virginia Tech.
`25.84
`CS/Z
`CS/H
`19.97
`31.73
`CS/H
`CS/H
`Concordia University
`40.86
`CS/Z
`52.63
`West Virginia University
`CSIZ
`22.25
`45.89
`Lawrence Technological Univ.
`CS/H
`CD/H
`DNS
`DNS
`DNS
`DNS
`Univ. of Michigan, Ann Arbor
`41.72
`CD/H
`CD/Ii
`Unfr. of California, Dads
`62.8
`24.61
`CD/H
`25.34
`Michigan Technological Univ.
`CSIZ
`DNF
`DNF
`DNF
`DNF
`University of Maryland
`DNS
`DNS
`DNS
`DNS
`Cal. State Univ., Northridgc
`46,3
`19,7
`CS/H
`CS/H
`Univ. of Wisconsin·Madison
`DNF
`DNF
`DNF
`DNF
`Uni,·. of Illinois at Chicago
`NIA
`53.63
`36.33
`NIA
`Ohio Siate Unh·.
`;;,;,K'!: i::::
`37.2
`22.2
`Stock Chenolet Lumina
`Stock Dodge Intrepid (3.S Lit•r) .:xHtt:
`"'' 34.6
`"'
`21.l
`;.;c;;:' .. ,,-,,,,
`::[~2:i~~mi 11: 35.9
`S1ock Ford Taurus
`22.2
`..
`CS s Charge Susta1rung • MPG result reflects on board fuel usage onl)'
`CD= Charge Depleting - Power plant efficiencies appli«I for depleted electrical energy
`Z = "Added ZEV Miles" SOC Correction me1hod, see rules
`H • HEV mode 1est used for SOC Correction SOChi and SOClow, see rules
`
`Combined
`(MPGE)
`30.46
`23.97
`45.43
`28.96
`DNS
`49. 14
`24.93
`DNF
`DNS
`26.57
`DNF
`42.5
`
`27.1
`25.6
`26.8
`
`SOC Adjus1ed Emissions
`co
`Met Dyno NOx
`N!\!HC
`Trace1?
`(gfmi)
`(g/mi)
`{g!mi)
`
`Yes
`Yes
`Yes
`Yes
`DNS
`Yes
`Yes
`Yes
`DNS
`Yes
`
`No
`Y•s
`
`0.497
`2.882
`0.077
`0.509
`DNS
`0.053
`25.96
`DNF
`DNS
`1.038
`DNF
`1.339
`
`3.33&
`0.183
`0.469
`10.725
`DNS
`9.642
`16.859
`DNF
`DNS
`0.224
`DNF
`0. 145
`
`0.177
`0.061
`0.004
`0.261
`DNS
`
`0.588
`4.821
`DNF
`DNS
`0,417
`DNF
`0.046
`
`Acceletarior
`Besr Time
`(seconds)
`11.224
`15.494
`15.263
`13.492
`DNS
`12.545
`11.644
`12.366
`DNS
`12.645
`23.798
`11.683
`
`PMIO
`
`NIA
`0.197
`
`NIA
`1.375
`NIA
`NIA
`NIA
`NIA
`
`NIA
`0. 109
`
`NIA
`
`O.Q65
`
`Lti, .. :,;,~} ;':~.
`
`:,;: ,~
`
`-:-·:'L:.·f".,!i:0~·~11
`
`10.373
`11.323
`
`IU'
`
`Handling
`Best Time
`(seconds)
`
`Consumer
`
`Accep. Oyn,
`(score)
`
`Other Awards
`
`32.75
`37.85
`35.69
`43.88
`DNS
`32.03
`34.06
`DNS
`DNS
`32.13
`DNS
`34.59
`
`50.00
`34.09
`15.35
`10.00
`DNS
`19.45
`22.76
`DNS
`DNS
`37.09
`DNS
`36.46
`
`'
`
`Univ. of CA. Dads
`1st Place
`Virginia Tech
`2nd Place
`Univ. of WI. Madison
`3rd Place
`West Virginia Univ.
`4th Place
`Ohio State Univ.
`5th Place
`Michigan Tech. Unh·.
`6th Place
`Univ. of CA, Oa,·is
`8es1 App. of Adv. Tech.
`Virginia Tech
`Best Consumer Acc.
`Besl Technical Report
`Univ. of CA, Dads
`8es1 Quality & Execution Univ. of WI, Madison
`Michigan Tech. Uni,·.
`Bes1 Mfg. Pct. & Cost
`Besl App. Adv. Materials Univ. of CA, Davis
`Uni\'. of CA, DaYis
`Ohio State Unh·.
`, ... "~;';~'.Fi 'I'?t'i::,}
`
`AC Eva!. & R<'•iew
`
`ii li;.,J · ~ I .. , ,~ 10.467 -wo,;,;.,c-
`
`BMW1025
`Page 7 of 20
`
`

`

`Ta ble B. 1997 FurureCar Challenge Results Sum mary
`
`Qu•li[)ing Written
`Technical
`Tuu
`Repon
`(Pa5'/Fail)
`
`Qu•lity&
`[xttufjon
`Re\·iew
`
`AppHucioo of M.anufacturing
`.Ad,·anted
`Pote1ui:d & Cost
`Ru·iew
`Technology
`
`IUchway
`Clty
`Energy
`f ntr:i·
`Tot>I
`Coniumer Economy Economy
`Acctptability
`Score
`Score
`
`Emissions
`
`Totol fl VAC
`
`Acceleration
`
`PaH
`
`70.00
`
`10.00
`
`56.ll
`
`70.00
`
`68.51
`
`67.77
`
`130.00
`
`130.00
`
`99.73
`
`100.00
`
`74.22
`
`50.2?
`
`100.00
`
`63.57
`
`100.00
`
`130.00
`
`100.00
`
`100.00
`
`130.00
`
`100.00
`
`J 7.J 7
`
`30.00
`
`19.7'
`
`J9.13
`
`60.00
`
`J0. 59
`
`60.00
`
`Readiness
`
`20.00
`
`9.00
`
`l0.00
`
`Handling
`so.oo
`
`50.00
`
`Endunnce
`
`Toi.I
`Pen•llies
`
`60.00
`
`38.00
`
`28.00
`
`11.00
`
`0.00
`
`T otal
`FCC
`Score
`
`1020.00
`
`829.99
`
`718.87
`
`School Name
`Axailable Points
`Uni\'. or CaJirornitl, Oa\'iS
`Virginia Te<-h.
`
`Uni\'. o(\Vi.scons:in-M:1dison
`
`\\'est \'iriinia Uni\'ersity
`
`Poss
`
`Pus
`
`Piss
`
`15.00
`
`20.00
`
`0.00
`
`63.93
`
`31.76
`
`39.66
`
`70.00
`
`53.17
`
`50.78
`
`89.82
`
`88.17
`
`49. 64
`
`90.22
`
`51.11
`
`39. 56
`
`69.JS
`
`53.46
`
`60.53
`
`55.00
`
`16.00
`
`125.94
`
`104.S-I
`
`64.76
`
`78.ll
`
`80.42
`
`6-1.21
`
`J9.J7
`
`100.00
`
`21.43
`
`21.18
`
`6.10
`
`39.12
`
`12.00
`
`53.25
`
`-17.18
`
`J 9.6 1
`
`35.66
`
`39.97
`
`60.00
`
`J0.00
`
`55.00
`
`0.00
`
`5.00
`
`8.00
`
`708.57
`
`691.64
`
`6-IUl
`
`Ohio Stole Univ.
`
`Michigan Te-chnological Unh·.
`
`Concordia University o( MontreaJ
`
`15.00
`
`11.00
`
`University of Mar>·•,1nd
`
`Pas.s
`
`P•n
`Pm
`
`Fall
`p..,
`
`J0.21
`
`36.62
`
`6'.76
`
`63.93
`
`61.81
`
`41.10
`
`68..16
`
`97.25
`
`26.00
`
`104.13
`
`100.00
`
`58.ll
`
`60.89
`
`88.44
`
`50.97
`ao.o
`34.63
`
`49.19
`
`27.28
`
`19.50
`
`20.00
`
`33.65
`
`15.00
`
`55.79
`
`l0.00
`
`38.95
`
`0.00
`
`23.68
`
`9.18
`
`20.21
`
`19.11
`
`53.83
`
`12.00
`
`ll.00
`
`42.04
`
`27.19
`
`0.00
`
`18.00
`
`60.00
`
`12.00
`
`5.00
`
`7.00
`
`1.00
`
`572.48
`
`465. 70
`
`429.38
`
`L:\wrence Technological Univ.
`Univ. or Illinois 1t Chicago
`c~t Su.te Uni..-., North.ridge.
`Univ. of Michiga11, Ann Arbor
`
`20.00
`o.oo
`2.00
`
`0.00
`
`0.00
`
`Pass
`
`Fail
`
`Fail
`
`3.U l
`
`S3.72
`
`14.00
`
`6•.•9
`
`J3. 18
`
`48.40
`
`H.00
`
`67.81
`
`S9.5S
`
`62.03
`
`80.19
`
`60.00
`
`52.19
`
`20.00
`
`3S.41
`
`35.8 ..
`
`31.44
`
`10.00
`
`28.53
`
`?6.00
`
`0.00
`
`0.00
`
`47.'2
`
`10.00
`
`0.06
`o.oo
`
`24.47
`o.oo
`o.oo
`0.00
`
`2l.l6
`
`6.00
`
`14.05
`
`HS
`
`26.67
`
`12.00
`o.oo
`0.00
`
`10.00
`
`0.00
`o.oo
`0.00
`
`33.00
`
`12.00
`
`11.00
`
`12.00
`
`141.00
`
`6.00
`
`40.00
`
`4.00
`
`371.93
`
`304.99
`
`240.53
`
`153.6J
`
`BMW1025
`Page 8 of 20
`
`

`

`TABLE OF CONTENTS - s.,P- I '3 5 ~
`
`1997 FutureCar Challenge
`
`California State University North ridge ............ .......... ........... ....... ..... 1
`Concordia University ...... .... ... .... ..... .................... ....... ............ .... .... 13
`Lawrence Technological University ........ ... .......... .......................... 29
`Michigan Technological University ......... ............ .................... ....... 41
`University of California , Davis .. ..... ............ ....... ................... ........ .. . 53
`University of Illinois, Chicago ................. ................ .. .................. ... 67
`University of Maryland ......... ..... .............. ... ...... .... .. .................... .... 75
`University of Wisconsin ....... .............. ........... .......... .......... ....... .... .. 87
`Virginia Tech ....... : ........... .... ..... ...... ..................... .. ..................... ... 99
`West Virginia University .... .. ....... ................................ ....... .. ....... . 115
`
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`Design and Development of Hyades, a Parallel Hybrid
`Electric Vehicle for the 1997 FutureCar Challenge
`
`James Swan, Jenny Spravsow, Greg Davis, Nick Brancik, Eric Beatti e, John Dombrowski,
`Brenda Settle, Robert Day, Paul Kornosky, Fabio Okubo, Richard Silas, Ri chard Johnson,
`Craig Hoff
`Lawrence Technological University
`
`Copyright © 1998 Society of Automotive Engineers. Inc.
`
`ABSTRACT
`
`The task given to the twelve universities in the 1997
`FutureCar Challenge was
`to modify an existing
`production mid-sized vehicle to me the goals set for the
`Partnership for a New Generation of Vehicles (PNGV).
`These goals included achieving a fuel economy of 34 km
`per liter. a range of 400 kilometers, and space for five
`passengers. The Lawrence Technological University
`entry is a charge depleting parallel hybrid electrical
`vehicle, built on a 1996 Ford Taurus chassis. The power
`train consists of a 32 kW Unique Mobility brushless DC
`motor with a Nickel Metal Hydride (NiMH) battery pack
`and a 1.9 L Volkswagen TOI engine , coupled to a f=ord
`Taurus SHO manual transmission . The transmission is
`sh ifted automatically using an electro-hydraulic control
`unit developed by team.
`
`INTRODUCTION
`
`Lawre nce Technological University was one of twelve
`universities selected to compete in the 1996/1997
`FutureCar Challenge. The FutureCar Challenge is the
`premiere, inter-collegiate engineering design competition
`to date and is sponsored by the U.S. Department of
`Energy (DOE) and the United States Council for
`Automotive Research (USCAR). Twelve competing
`universities received a 1996 Chevrolet Lumina, a 1995
`Dodge Intrepid, or a 1996 Ford Taurus. The vehicle was
`modified to meet the goals of the Partnership for a New
`Generation of Vehicles (PNGV) program; to develop
`enabling technologies leading to the production of
`mid-sized vehicles , to achieve three times the current
`a-.erage fuel economy, and to maintain the performance ,
`utility, and affordability of modern sedans. To try to meet
`these goals L TU will im plement a parallel Hybrid Electric
`Vehicle in a 1996 Ford Taurus.
`
`A Hybrid Electric Vehicle (HEV) is defined as a vehicle
`that can draw propulsion power from both of the
`following sources of energy: (1) consumable fuel and (2)
`an energy storage system (e.g., batteries) that is
`
`capable of being charged by an on-board generator or
`an off-board source. The systems may be combined in
`any configu ration (e.g ., series or parallel). An HEV is
`considered to be charge depleting (SAE Draft J1 711) if
`during vehicle operation over a given driving schedule,
`.electrical energy originally supplied from an off-board
`source is depleted during the same time that the
`on-board consumable fuel is used.2
`
`VEHICLE DESIGN
`
`The overall design goals were to produce a vehicle with
`increased fuel efficiency and reduced emissions while
`retaining the reliability and driveability of a conventional
`vehicle. In order to achieve this, every effort was made
`to improve sub-system efficiencies and to reduce vehicle
`weight and aerodynamic drag. The largest gains were
`made by replacing the powertrain with one that is more
`energy efficient. Additional benefits were achieved
`through the use of lightweight materials and by reducing
`the vehicle drag and rolling resistance .
`
`Computer Simulation - To determine the best possible
`control strategy, computer programs were developed to
`analyze both the city and highway cycles of the Federal
`Test Procedure (FTP).
`The ana lysis
`focused on
`instantaneous energy used by the vehicle power plant.
`Vehicle speed and acceleration were tabulated in one(cid:173)
`second intervals. These two knowns, coupled with the
`vehicle weight and drag, were used to calculate the
`tractive force, revolutions per minute at the wheels and
`energy consumption in kWh/ km. Additional analysis
`focused on maximizing the overall drivetrain efficiency
`by experimenting with various operating scenarios . For
`example. during the city-cycle, the vehicle is at rest
`approximately 420 seconds out of 1878 seconds. The
`decision to shut the diesel engine down during idle
`periods resulted in reduction of fuel consumption by
`approximately 20%.
`
`the amount of
`The computer simulation predicted
`electrical assist necessary
`to provide acceptable
`
`29
`
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`

`performance during the FTP city and highway cycles.
`The power assist from the electric traction motor was
`defined as the percent of total power needed
`to
`accelerate the ca r during the driving cycle. The amount
`of electrical assistance is co ntinuously modulated to
`obtain the best possible eng ine efficiency based on the
`power output, engine
`revolutions per minute. and
`accelerator pedal position. This simulation indicated that
`on average 15%-20% electrical assist during the FTP
`city cycle, 5%-7% electrical assist during the FTP
`highway cycle, no electrical assist at idle. and no
`electrical assist above 70 kph would yield the best
`efficiency and driveablility.
`
`Figure 1: Hyades Powertrain Layout
`
`Powertrain Selection - The design chosen was a parallel
`HEV powertrain. shown in Figure 1, which coupled a 32
`kW phase advanced brushless DC electric traction motor
`via an aluminum bridge assembly to a small 67 kW
`turbocharged direct
`injection diesel engine.
`The
`combination provides tractive energy to the front wheels
`through a manual transmission, which is mechanically
`shifted by the on-board computer, rather than by the
`driver. The electric assist enables the vehicle to operate
`at an equivalent power level of a conventional veh icle.
`while maintaining lower emission levels and improved
`fuel economy. The estimated increase in fuel econo my
`due to the new powertrain is about 100% compared to
`the standard Ta urus as shown in Table 1.
`
`Table 1: Fuel Economy of Hybrid Compared to Stock
`
`Taurus
`
`Cd
`
`City Fuel
`Economy
`(km/L)
`
`Highway Fuel
`Economy (km/L)
`
`Stock
`
`Hybrid
`
`.32
`
`.32
`
`8.03
`
`16.45
`
`12.04
`
`23.38
`
`Three powertrain co nfigurations were compared: a heat
`engine. a series HEV, and a parallel HEV. The heat
`engine option was quickly dismissed. To meet the fuel
`economy goal the engine would be sized too small to
`
`30
`
`the accelerat ion
`for
`provide adequate performance
`requirement. A series configuration employs an engine.
`which produces electric power for the electric motor and
`batteries through a generator. The series HEV offers
`better efficiency at low speeds because the engine is
`decoupled from the drivetrain and can thus operate at or
`near peak efficiency regardless of vehicle speed.
`In a
`parallel configuration , both the engine and the electric
`motor are used for propulsion. At hig her speeds. the
`parallel qrive is often more efficient since the engine can
`be sized so that it is operating near peak efficiency.
`Further, because the engine is directly coupled to the
`drivetrain. two of the energy conversion processes of the
`series HEV are not required (engine to electric. and from
`electric back to mechanical) , making the parallel system
`more efficient. Over a range of speeds, the parallel and
`series HEV configurations' overall fuel economy are
`comparable. Despite the com plexity of the parallel
`system. it offers greater reliability than a series system
`due to a limp home mode using either the engine or the
`motor. Further. the parallel configuration provides better
`acceleration and passing abilities, and
`thus better
`maintains the performance of a conventional vehicle.
`This
`led
`to
`the decision
`to choose
`the parallel
`configuration, where the electric motor is used to assist
`the engine in meeting heavy load demands. The level of
`assist is adjusted in order to keep the diesel engine
`operating in it's most efficient range.
`In order to best
`utilize
`the electric energy storage and
`to achieve
`maximum normal range, Team Hyades has modified a
`1996 Ford Taurus producing a charge depleting parallel
`HEV in Normal Mode.
`
`Motor Selection • The electric. or traction. motor is a 32
`kW phase advanced brushless DC design.
`The
`advantages of the brushless DC motor are: higher
`efficiency, higher power density, better heat dissipation.
`and increased motor life compared to a conventional
`brushed motor. The brushless DC motor experiences no
`losses due to brush friction while having two to three
`times more torque than a brushed DC of equivalent size
`and weight. The electric motor utilizes high efficiency,
`liquid cooled, 18 pole neodymium iron boron permanent
`magnets, with
`four-quadrant operation. and
`a
`microprocessor-based
`controller.
`The
`controller
`incorporates closed loop torque control. which allows the
`motor to be used with conventional
`throttle based
`operator control. The peak efficiency of the motor alone
`is 95%. However. when the power generat ion and line
`transmission efficiency of 37 .27% is accounted for, the
`electrical efficiency drops to 37.4%.
`
`Engine Selection • The 1.9-liter diesel engine was
`chosen from a pairwise comparison of several engines
`including IC engine , gas turbine. and Stirling engine.
`The
`selection
`criteria
`investigated
`performance
`characteristics. which
`included
`emissions,
`fuel
`consumption . acceleration . and endurance. The Stirling
`and gas turbine engines were not used due to extremely
`limited availability. Additionally, the gas turbine was
`found to be inferior during the tra nsient speed and load
`conditions experienced in the parallel design . The
`
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`four stroke,
`four cylinder,
`is a
`chosen engine
`turbocharged d irect injected (TOI) diesel engine. The
`turbocharger provid es an extra boost and excess air for
`minimum particulate emissions. This engine boasts a
`peak therma l efficiency of 43% and
`is capable of
`meeting strict em ission standards. Further, this engine
`has better part-load efficiency characteristics
`than
`gasoline engines.
`
`Transmission Selection - A Ford model RBE-AR five(cid:173)
`speed manual tran smission was selected to replace the
`stock automatic because it reduced weight, improved
`efficiency, and packaged well in the stock chassis and
`transmission half-shafts were utilized
`cradle.
`The
`because they matched the existing vehicle track width .
`The transmission weight is 42.6 kg to give a weight
`advantage of 34.5 kg and decreased rolling resistance of
`20% compared to the stock system. In order to maintain
`the consumer acceptability of an automatic transmission,
`a hydraulic shifting mechanism was desig ned and
`implemented. Research shows that this system offers
`efficiency advantages over other altematives. 3
`
`Control System Hardware - The Programmable Log ic
`Controller (PLC) . with digital and analog input/output
`(1/0) cards. is responsible for real-time processing of all
`input comma nds and updating outputs in order to control
`the powertrain.
`The PLC
`takes
`inputs
`from
`Analog/Digital (A/D) converters (used to sense throttle
`posit ion and vehicle speed) and from the user control
`panel. The PLC power supply requirement of 24 voe is
`suppl ied
`from the
`traction battery pack via DC-DC
`converters. All 1/0 cards are grounded to the vehicle
`common ground.
`The PLC
`is capable of being
`programmed in ladder logic. Boolean. and statement list
`languages. The Hyades control program is written in the
`ladder logic programming
`language because of its
`graphic, self-explanatory nature. The PLC utilizes a
`main program. which cycles continuously. From this
`main program, all su broutines, or "function blocks" are
`called . A separate function block was created for
`initialization of variables upon startup. T he startup block
`runs only once. before the first execution of the main
`block. The program for Hyades consists of the main
`block and 12 function blocks. A conditional return to the
`main block is contained in each subroutine depending on
`the mode of vehicle operation selected and whether a
`gear shift is in process.
`
`input via
`takes user
`The operator control panel
`This unit has memory
`user-defined function keys.
`storage. which is independent of the PLC. A backlit
`liquid crystal display and a serial data stream. which
`allows comm unication with the PLC, are the availabl e
`control panel outputs. The control panel outputs are a
`backlit liquid crystal display and a serial data stream,
`wh ich allows communication with the PLC. The control
`panel is powered by the same 24 voe supply as the
`PLC.
`
`Battery Selection - The selection criteria for the batteries
`included weight, power storage, charging rate, safety,
`
`31
`
`and longevity. The Nickel Metal Hydride (NiMH) battery
`has the best power to weight ratio compared to available
`alternatives. Each module has a nominal voltage of 13.2
`volts with a maximum voltage of 16 volts after charging.
`The module has 1.25 kWh of energy and a weight of
`17.8 kg. The physical dimensions of each module are
`102 mm by 179 mm by 412 mm. The performance
`specifications are described in Table 2. The operating
`temperatures of the NiMH are: less than 45 C to achieve
`than 55 C
`to obtain 80%
`maximum
`life.
`less
`performance, and less than 65 C to avoid damage. The
`United States Advanced Battery Consortium has
`identified the NiMH as having the potential to meet
`mid-term criteria .
`It has outlasted other battery
`technology because the material to produce the battery
`is readily available.4
`
`Table 2: NiMH Pe rformance Specifications
`
`Specific Energy
`
`Energy Density
`
`Specific Power
`
`70 Wh/kg
`
`165 Wh/L
`
`250 W/kg @ 50% SOC
`
`220 W/kg @ 20% SOC
`
`Fuel Selection - Dimethyl Ether was in itially considered
`because it is the most environmentally benign choice.
`Exhaust from a DME-driven diesel engine contains no
`sulfur, almost no soot. and only a bout 20% of the
`nitroge n oxides
`that a diesel produces.
`The
`hydrocarbons
`in
`the exhaust are also dramatically
`reduced. However, DME is a gas at room temperature
`and in order to be used as a liquid fuel. it has to be
`bottled under pressure. There is less energy in a given
`amount of DME than in the same amount of diesel ;
`therefore, bigger fuel tanks are needed . The cost , the
`distribution, and th e availability of DME also dims the
`use of DME in the near future because producing DME
`means more expensive equipment for more chemical
`processes and several years to build production plants.
`
`Biodiesel used in a 20 percent blend of soybean oil with
`petroleum diesel was chosen as the fuel. Combined
`with the catalytic converter it will reduce air pollution.
`reduced 31 percent. carbon
`Particulate matter
`is
`monoxide by 21 percent and total hydrocarbons by 47
`percent. It also reduces sulfur emissions and aromatics.
`Vvtiile its emiss ions are radically lower, biodiesel can be
`substituted for diesel with no engine modifications. and
`In
`maintains the payload capacity and range of diesel.
`addition, biodiesel has about the same energy content
`as diesel: 128,800 Btu/gallon, compared to 130,500
`Btu/gallon of diesel. Production cost of biodiesel is
`60-80 cents per gallon more than diesel alone, and it
`requires no special storage facilities .
`In fact. it can be
`stored wherever petroleum diesel is stored, except in
`concrete-lined
`tanks. due
`to
`the adverse chemical
`reaclions.5
`
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`Emission Control - The emission control target was to
`achieve the California ULEV emission level when the
`vehicle operates in Normal Mode. The stock two-way
`catalytic converter reacted with carbon monoxide and
`unburned hydrocarbons. To reduce all emissions, the
`original two-way catalytic converter was replaced with a
`three-way converter equipped with an absorber. The
`cold-start gases from the engine are stored
`in the
`absorber until the temperature of the catalyst is high
`enough to burn the gases within it's ceramic substrate.
`Additionally, the engine is shut down during extended
`coastdowns and when the vehicle is stationary. This
`reduces fuel consumption and helps to maintain catalytic
`converter temperatures above the levels required for
`acceptable conversion efficiencies during
`the
`idle
`portions of the federal California Vehicle Standard (CVS)
`emission test. This is possible because the engine is no
`longer pumping large quantities of lean exhaust gas
`through the catalyst.
`
`A phenolic resin spacer has been put in
`the area
`between the intake manifold and eng ine block. The
`phenolic intake manifold spacer was utilized to minimize
`heal conduction from the cylinder head to the intake
`manifold. This was done to cool the intake charge in
`order to lower nitrogen oxide emissions. The exhaust
`spacers were fabricated for packaging concerns since
`the phenolic intake spacer pushed the intake manifold
`away from the cyl inder head. towards the exhaust
`manifold.
`
`Finally, an exhaust gas recirculation (EGR) cooling
`system was implemented. The heat exchanger uses
`engine coolant to cool the EGR as it flows between the
`exhaust and intake manifolds. This helps to further
`reduce combustion temperatures, leading to lower NOx
`formation. Additionally, this system also provides faster
`engine warm-up, further reducing cold start emissions.
`
`POWERTRAIN CONTROL STRATEGY
`
`The PLC maintains control of the vehicle powertrain .
`which determines the percentage electric assist to the
`diesel , starts and stops the engine, and shifts the
`transmission. The percent of motor assist is dependent
`on accelerator pedal position and vehicle speed, which
`are accurate indicators of the load requirements for the
`powertrain .
`
`Operating Modes - There are three modes of operation:
`Normal (parallel HEV), Motor or Zero Emissi