automotive research in vehicle dynamics laboratory
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Automotive Research in Vehicle Dynamics Laboratory. Introduction Active Safety Hybrid and Fuel Cell Vehicles Conclusions. Huei Peng. Department of Mechanical Engineering The University of Michigan. Vehicle Dynamics Laboratory. Professor Huei Peng - PowerPoint PPT PresentationTRANSCRIPT
Automotive Research in Vehicle Dynamics Automotive Research in Vehicle Dynamics LaboratoryLaboratory
Huei Peng
Department of Mechanical EngineeringThe University of Michigan
Introduction
Active Safety
Hybrid and Fuel Cell Vehicles
Conclusions
Huei Peng Research Summary 2008/02/11 - 2
Vehicle Dynamics LaboratoryVehicle Dynamics Laboratory
Professor Huei Peng
Currently 12 Ph.D. students, 1 M.S. student and 5 visiting scholars
Huei Peng Research Summary 2008/02/11 - 3
Major Issues of Ground VehiclesMajor Issues of Ground Vehicles Sustainability
Energy Environment
Quality/Functionality
Safety
Workforce
Huei Peng Research Summary 2008/02/11 - 4
OutlineOutline
Introduction
Active Safety
Hybrid and Fuel Cell Vehicles
Conclusions
Huei Peng Research Summary 2008/02/11 - 5
Active Safety ResearchActive Safety Research
Chassis Control ESC, road departure warning, CW/CA, Rollover
prediction and prevention, Active Suspension, Integrated Chassis Control
Worst-case evaluation methodology
Driver model development through naturalistic driving database
Huei Peng Research Summary 2008/02/11 - 6
Active Safety TechnologiesActive Safety TechnologiesRollover generation, prediction
and prevention
Performance evaluation of VDC
5.5 km, 2 lanes
ACC effect on Traffic flow
0
500
1000
1500
2000
2500
3000
3500
0 20 40 60 80 100 120
Density(vehicles/lane/km)
Flo
w r
ate(
veh
icle
s/la
ne/
hr)
Aggressive Drivers (Estimated)Conservative Drivers (Estimated)Modified Gipps ModelI 80, Hayward, CA(1995)Merritt Parkway(1957)Lincoln Tunnel(1959)Tokyo-Nagoya(1996)
Driver model development
0 2 4 6 8 10 12-0.5
0
0.5
1
1.5
2
2.5
3
3.5
TTR
ArcSimTTR
seco
ndsTime (sec)
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Worst-Case Evaluation MethodWorst-Case Evaluation Method
DASdesign
Open-loop Simulations
HIL Simulations
Field tests
Worst-case Simulations
DesignIteration
Standard test matrix
Worst-case test matrix
Human driver Model
Doi, Nagiri and Amano, Toyota 1998
Huei Peng Research Summary 2008/02/11 - 8
Mathematical FormulationMathematical Formulation
Given a nonlinear vehicle dynamic model , where the disturbance input includes front wheel steering angle and brake pedal command . The control input includes the ABS pressure command , CDC damping and VDC pressure command . The control algorithms of the ABS and VDC modules are assumed to be known. Find, within saturation bound and , the signal which maximizes a cost function . The matrix Q is selected such that the vehicle side slip or roll angle is maximized.
( , , , )uf x twx w
p
ABSp
VDCP
max max 0 p pmax
u
J(x,w, t) xT0
T (t)Qx(t) uT (t)Ru(t) wT (t)Pw(t)dt
c
Huei Peng Research Summary 2008/02/11 - 9
Worst-case LibraryWorst-case Library
• A rollover-worst-case database was created. Many result in rollovers, the rest at least single wheel lift-off.
• Useful for VDC evaluation and re-design.
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Vehicle or ESC Performance EvaluationVehicle or ESC Performance Evaluation
Huei Peng Research Summary 2008/02/11 - 11
Rollover Accident due to an Initial Rollover Accident due to an Initial Sideswipe CollisionSideswipe Collision
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Rollover Accident Simulation & Avoidance by Rollover Accident Simulation & Avoidance by PISCPISCWithout Control
With PISC Control
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Rollover Accident at an IntersectionRollover Accident at an Intersection
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Accident Reconstruction & Control ComparisonAccident Reconstruction & Control Comparison
Red sedan: bullet vehicle
Blue sedan: target vehicle without post-impact control
Yellow sedan: target vehicle with post-impact control
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40 60 80 100 120 140 160 180 200 220-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Control ends
Longitudinal displacement [ X (m) ]
Lat
eral
dis
pla
cem
ent
[ Y
(m
) ]
Impact begins
1) Differential Braking Only
2) Differential Braking + Active Steering
3) Full Braking, No Steering
4) No Braking, No Steering
Comparison of TrajectoriesComparison of Trajectories
3 lane width
* 1 sec after impact 3 sec after impact
Huei Peng Research Summary 2008/02/11 - 16
Vehicle Motion DatabasesVehicle Motion Databases
SAVME Urban street Large human driver population but shorter horizon
(<15 seconds)
ICC FOT Highway + local roads (naturalistic use) Relatively longer cases (<200 seconds)
ACAS
RDCW
Huei Peng Research Summary 2008/02/11 - 17
SAVME data collection & archivingSAVME data collection & archiving
• System for Assessment of the Vehicle Motion Environment
• 30,561 vehicles, Plymouth road, Ann Arbor, MI, USA
600 ft
200 ft
Digital video cameras
100f
t
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ICC FOT databaseICC FOT database
HostVehicle
Main beam(133m)
Side beam (32m)
Width4.4m
108 drivers.
Mostly highway
In car instrumentations
114,000 total miles (68,000 miles manual)
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ACAS FOT DatabaseACAS FOT Database
•Total traveled distance: 137,000 miles, 1,500 miles per driver.
•Database: 164 GB in volume; contains approx. 400 engineering variables sampled at 10 Hz, as well as synchronized road forward-view video clips.
Category Channel Description Resolution
Driver Driver number 1- 96 - Trip Trip number - Index Time Time since DAS started 0.1 sec AbsSpeed Vehicle speed from ABS 0.3 m/ sec YawRate Yaw rate - positive = turning right 0.01 deg/ sec AxFiltered Filtered longitudinal acceleration 0.01 m/ sec2 CIPVRange Range to closest in-path vehicle 1/ 64 m CIPVRangeRate Range rate of closest in-path vehicle 1/ 8 m/ sec Distance Trip distance 0.01 m HeadingInLane Vehicle heading angle in lane - positive = turning right 0.1 deg
Kinematics
LaneOffset Host offset from lane center - positive = going right 0.05 m Throttle Throttle opening 1% Brake Brake active On-Off Operation Steer Steering wheel angle 1 deg C0 C0 from data fusion - Curvature 1/ m C1 C1 from data fusion - Curvature rate 1/ m2 LaneWidth Lane width 0.05 m
Road
RoadClass Functional Road Class -
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Road Departure Crash Warning Road Departure Crash Warning System DatabaseSystem Database
11 test vehicles Nissan Altima 2003
78 FOT drivers Evenly by gender Three age groups 82,773 miles of driving 2,487 hours
Over 400 signals captured at 10 Hz or faster 204 GB numerical data 135 GB video data
Huei Peng Research Summary 2008/02/11 - 21
OutlineOutline
Introduction
Active Safety
Hybrid and Fuel Cell Vehicles
Conclusions
Huei Peng Research Summary 2008/02/11 - 22
Hybrid Vehicles StudiedHybrid Vehicles Studied
Series Parallel Split
HEV
HHV
FCHV
FTTS (2000)
Power Bus
Gearbox Gearbox Gearbox Gearbox
Motor Motor Motor Motor
Battery
IM
Inte
r co
oler
Air
Exhaust Gas
Gearbox
C
EMT
ICM
Engine
Generator
Power Control Module Power
Requirement
IMIn
ter
coo
ler
Air
Exhaust Gas
TrnsTC
C
EMT
D
Traction Force
PS
DS
DS
ICM
Vehicle Dynamics
EngineDrivetrain
Motor
Battery
Power Control Module
International Truck (2001)
FMTV (2002)
Re s e r v o ir
A c c u m u la t o r
D-R
1
T r an s
T/CICM
D-R
2
Tr-
C
D-F T
r-C G
ear
bo
x
P/ M
Pow e rCont ro lModule
Eaton/Fed Ex (2004)
DCX Natrium (2005)
Super-HMMWV (2006)
Super-HMMWV (2006)
Super-HMMWV (2007)
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Key Problems in Hybrid Vehicle DesignKey Problems in Hybrid Vehicle Design
Configuration selection and model generation
Component sizing
Control DP/SDP algorithms as the assessment tool/benchmark SDP/other algorithms for implementation
Power SplitEVT
Vehicle
Engine
M/G2
M/G1
Battery
Vehicle Vehicle ModelModel
Fuel consumption, DistanceFuel consumption, Distance
Input stateInput state Output stateOutput state
Power demandPower demand
Power errorPower error
)(
)(
)(
kV
kGr
kNe
)1(
)1(
)1(
kV
kGr
kNe
ThrottleThrottleGear shiftGear shiftAFM AFM ModeMode
Huei Peng Research Summary 2008/02/11 - 24
Possible Design ProcessPossible Design Process
Automatically-Generated Dynamic Modelsa. Selection of the powertrain configurationb. Selection of the mechanical parameters c. Selection of the powertrain component sizes
Model Based DP ControlTheoretical best performance (non-causal)
Model Based SDP or ECMS ControlImplementable control strategies
iteration
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SummarySummary
Energy
Environment
SafetyEducation
The main research objectives of the Vehicle Dynamics Laboratory at the Michigan Ann Arbor are to enhance the safety/energy/environment performance of ground vehicle—through working with and education top graduate students.