Validation Process of a HEV System Analysis Model: PSAT

November 2004

Aymeric Rousseau,Phil Sharer and Maxime PasquierArgonne National Laboratory

Sponsored by Lee Slezak

This presentation does not contain any proprietary, confidential, or otherwise restricted information

Outline

PSAT Introduction 

Vehicle testing

Component Validation

Control Strategy Understanding

Drivetrain Validation Drivetrain Validation

Conclusion

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ANL System Analysis Program

Modeling, testing, and hardware control usedto investigate various technologies of advancedvehicles (diesel emissions, CVTs…)

1. Modeling software: PSAT2. Development/integration of new

models/data into PSAT

1. Control software: PSAT-PRO2. Rapid Prototyping (RP) 3. Hardware In the Loop (HIL)models/data into PSAT

3. Control strategy developmentp ( )

MODELING PROTOTYPING

EXPERIMENTALTESTING

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1. Instrumentation2. Emissions equipment3. Data processing

What is PSAT? Developed by ANL under the direction and with the Developed by ANL under the direction and with the contribution of Ford, General Motors and DaimlerChrysler for contribution of Ford, General Motors and DaimlerChrysler for the Partnership for New Generation of Vehicle (PNGV)the Partnership for New Generation of Vehicle (PNGV)the Partnership for New Generation of Vehicle (PNGV)the Partnership for New Generation of Vehicle (PNGV)

Funded by USCAR and now by DOEFunded by USCAR and now by DOE

A powerful forwardA powerful forward--looking modeling tool that allows the looking modeling tool that allows the user to realistically simulate:user to realistically simulate:

F l ti d h t i i ( F d l T tF l ti d h t i i ( F d l T tFuel consumption and exhaust emissions (e.g. Federal Test Fuel consumption and exhaust emissions (e.g. Federal Test Procedure, highway, all other cycles)Procedure, highway, all other cycles)

Performance (e g 0Performance (e g 0 30mph 030mph 0 60 mph 4060 mph 40 60 mph60 mphPerformance (e.g. 0Performance (e.g. 0--30mph, 030mph, 0--60 mph, 4060 mph, 40--60 mph, 60 mph, distance in 5 sec., maximum launch grade, maximum distance in 5 sec., maximum launch grade, maximum continuous speed, 55mph at 6% grade)continuous speed, 55mph at 6% grade)

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Forward Looking ModelingForward looking models (PSAT) represent how systems respond in realityIn a vehicle, the driver input creates the vehicle response

Commands from a Powertrain Controller to obtain the desired vehicle speedCommands from a Powertrain Controller to obtain the desired vehicle speed

Forward looking modeling is consistent with industry practice for vehicle design Forward looking modeling is consistent with industry practice for vehicle designAccurate representation of a dynamic system (e.g. engine starting, shifting, clutch engagement / disengagement…) Possibility to implement advanced component models (e.g. 1D engine y p p ( g gmodel to characterize emissions…) Develop control strategies that can be later tested on a bench or in a vehicle Small time step

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p

Extensive Data Collection With Torque Sensors

SpacerSpacer

THS

Engine 

addedadded

~5”

THSTransaxle 

Half‐shaft input 

Damper 

Torque Sensor Spacer 

Prius engine torque sensor AxleAxle

Strain Gage CollarStrain Gage Collar

Insight axle torque sensor

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Strain Gage CollarStrain Gage Collar

Different Types of Tests Are Needed Steady‐state speeds

Vehicle Speed

Succession of accelerations and decelerations at different speedsTime

Succession of accelerations and decelerations at different speeds

Standard cycles (EUDC, Japan…)

Vehicle Speed

Time

Each 1mn

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Each 1mn

Control Strategy Understanding

500

600

Vehicle Speed (m/s) * 100

400

500 Vehicle Speed (m/s) 100Engine Speed (rad/s) Generator Speed (rad/s) SOC (ratio) * 1000 Motor Current*10 (amps)

200

300

0

100

0 50 100 150 200 250 300 350-200

-100

8

secSource: ANL data

Acceleration / Deceleration Tests

150 3

50

100

1

2

0

50

3 0 0 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0

0

1

MPa

-50 -1

kph

-100 -2

kphCurrent [A]Front Brake [MPa]Rear Brake [MPa]

Regen

9

-150 -3Source: ANL data

What is the Uncertainty of Each Model?

Physical Vehicle Simulated Component

Measured Current SimulatedMeasured Current

d l Si l d l

Simulated SOC

Measured Voltage = Simulated Voltage

Valid Battery Model

Measured SOC = Simulated SOC

y

10

Battery and Engine Validation

0 6

0.62Battery SOC

Simulated (Amps integration) Measured (Amps integration)Measured (Scan Tool)

Battery ValidationSimulated (Amps integration) Measured (Amps integration)Measured (Scan Tool)

OC 0.56

0.58

0.6 Measured (Scan Tool)Measured (Scan Tool)

SO

0.52

0.54

2

x 10-3 Engine Fuel Rate Validation

simulatedmeasured

0 100 200 300 400 500 600 700 8000.5

sec

1

1.5

g/s

0.5

1

Engine Validation

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Source: ANL data 100 150 200 250 3000

sec

Control Strategy May Differ From One Cycle to Another One

Highway CycleEngine torque vs. Engine Speed

Japan 10-15

to Another One

g y yp

Simulated best efficiency curve

Test data

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Source: ANL data

Specific Tools Are Necessary to Understand HEV Control Strategies

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The Japanese Prius Does Not always Follow the Best Efficiency Curve

Prius Engine Map – Efficiency = f(Speed ,Torque)

Estimated Best Efficiency curve

the Best Efficiency Curve

Estimated Best Efficiency curve

Change of torque when a mediumVariation of the pedal demand occursVariation of the pedal demand occurs

Change of speed when a largeVariation of the pedal demand occurs

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PSAT Prius Validation is Within 5%Cycle Cons

test mpg

Cons simul mpg

Diff in % SOC init SOCf test

SOCfsimul

Diff in %

Japan 10-15

44.9 45.1 0.4 0.600 0.580 0.583 0.5

J 48 8 50 7 3 9 0 610 0 575 0 561 2 3Japan 10-15

48.8 50.7 3.9 0.610 0.575 0.561 2.3

EUDC 44.0 43.8 0.4 0.610 0.605 0.593 2.0

FHDS 48.2 46.7 3.2 0.550 0.571 0.573 0.3

UDDS 42.3 39.9 5.9 0.550 0.530 0.570 8.7

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Component Behavior is ValidatedEngine Speed

200

250measured simulated

Rd/s

50

100

150

Sec0 100 200 300 400 500 600-50

0

700

Engine Torque

40

60

80

100

Engine Torque

Nm

40

-20

0

20

40

16

Sec0 100 200 300 400 500 600 700

-60

-40 simulatedmeasured

Conclusions

HEVs require new approach for validation

A validation methodology has been developed for A validation methodology has been developed for HEV validationSpecific tests have been definedSpecific tools have been developed

The Japan Toyota Prius has been validated within 5% onThe Japan Toyota Prius has been validated within 5% on different cycles with different SOC using PSAT

The generic methodology and tools developed can be applied to any HEV validation process

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