P.O. Box 2CharlburyOxonOX7 3PDUK

Tel: 44(0)1608 810334Fax: 44(0)1608 811486email: forbes@perbury.co.uk

Presented at Bath University, March 1st. 2006

Automotive Fuel Economy and the IVT

F.G.Perry

Perbury Engineering Ltd.

Eur.Ing, C.Eng, M.I.Mech.E, M.R.Ae.S

Perbury Engineering Ltd.

OUTLINE

Single Regime IVT (Infinitely Variable Transmission)

Fundamental Power Requirements

Perbury Multi-Regime IVT

Engine Optimum Operating Line

Typical Fuel Consumption

Bath University/NREL Simulation

Predictions for Perbury IVT

Summary – How to increase MPG

Conclusions

Perbury Engineering Ltd.

Road Load HP

0

10

20

30

40

50

60

70

0 20 40 60 80 100

MPH

RO

AD

LO

AD

H

P

Typical 2000 lb, 70 bhp car

Perbury Engineering Ltd.

Engine Fuel Map and Vehicle Gearing

0

20

40

60

80

100

1 2 3 4 5

Engine RPM – 000s

Tor

que

– lb

ft

80

60

30

MP

H

25

19 M

ph/1

000

rpm

34

40

MaxPower

240

250 g/kW.h

270

300

400

800

600

1000

90

MaximumTorque

Perbury Engineering Ltd.

Single Regime IVT

Perbury Engineering Ltd.

Perbury Engineering Ltd.

Perbury Engineering Ltd.

Perbury Engineering Ltd.

Pinion Speed Ratio W.O. Variable Ratio

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80

Variable Ratio

Pin

ion

Sp

ee

d R

atio

Low Regime

High Regime

Reverse

Perbury Engineering Ltd.

Regime Efficienciesincludes all parasitic losses

82

84

86

88

90

92

94

96

0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

Variable Ratio

Eff

icie

ncy

%

Low

High

Reverse

Perbury Engineering Ltd.

Engine Fuel Map and Vehicle Gearing

0

20

40

60

80

100

1 2 3 4 5

Engine RPM – 000s

Tor

que

– lb

ft

80

60

30

MP

H

25

19 M

ph/1

000

rpm

34

40

MaxPower

240

250 g/kW.h

270

300

400

800

600

1000

90

OptimumLine

MaximumTorque

30

40

50

60

70

80 90

With efficiencies

Perbury Engineering Ltd.

Transmission ratio for minimum fuel consumptionincluding efficiencies

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0 20 40 60 80 100MPH

Re

du

ctio

n |

Ove

rdri

veOverdrive bypass

Perbury Engineering Ltd.

MPG vs MPH at Constant Speed

0

10

20

30

40

50

60

70

20 30 40 50 60 70 80 90 100

MPH

Mile

s/U

K G

allo

n

Manual (97%)

Perbury Engineering Ltd.

MPG vs MPH at Constant Speed

0

10

20

30

40

50

60

70

20 30 40 50 60 70 80 90 100

MPH

Mile

s/U

K G

allo

n

0

20

40

60

80

100

120

140

% I

ncr

ea

se

IVT (84-94.5%) Manual (97%) % Increase

Perbury Engineering Ltd.

2000 Honda Insight Hybrid

Perbury Engineering Ltd.

Perbury Engineering Ltd.

Introduction to ADVISOR

ADVISOR, NREL’s ADvanced VehIcle SimulatOR, is a set of model, data, and script text files for use with Matlab and Simulink.  It is designed for quick analysis of the performance and fuel economy of conventional, electric, and hybrid vehicles.  ADVISOR also provides a backbone for the detailed simulation and analysis of user defined drivetrain components, a starting point of verified vehicle data and algorithms from which to take full advantage of the modeling flexibility of Simulink and analytic power of Matlab. ADVISOR was preliminarily written and used in November 1994.  Since then, it has been modified as necessary to help manage the US DOE Hybrid Vehicle Propulsion System subcontracts. Only in January 1998 was a concerted development effort undertaken to clean up and document ADVISOR.

Since then, researchers at Chrysler Corp. General Motors Corp. AlliedSignal Automotive Argonne National Laboratory Naval Research Laboratory University of California-Davis University of Maryland University of Illinois-Urbana/Champaign and other research institutions have used ADVISOR to predict the performance of their vehicles, do studies on the effect of control strategy on emissions and fuel use, among other things.

Perbury Engineering Ltd.

MPG vs Minimum Engine RPMM

inim

um E

ngin

e S

peed

- R

PM

800

900

1000

1100

1200

1300

1400

1500

60 70 80 90 100 110 120 130

SC03

FTP

US06

HWFET

Av.Av. Accel

Cycle Stops Miles MPH ft/sec2

HWFET 1 10.26 48.2 0.64US06 5 8.01 47.97 2.2SC03 6 3.58 21.44 1.65FTP 22 11.04 16.04 1.68

Modified Min. Engine RPM

UK MPG

Perbury Engineering Ltd.

Starting Optimum Line

0

10

20

30

40

50

0 500 1000 1500 2000

Engine RPM

To

rqu

e -

lb

ft

Feasible

Used in thesimulation

Perbury Engineering Ltd.

Car Weight 2000 lbEngine bhp 50 kW maxSFC Max 0.35 lb/bhp.hr

213 g/kW.hr

Acceleration Times

0

2

4

6

8

10

12

14

0 10 20 30 40 50 60 70

MPH

Se

con

ds

Perbury Engineering Ltd.

MPG vs MPH - Honda Insight

0

20

40

60

80

100

120

140

160

20 30 40 50 60 70 80 90 100

MPH

MP

G (

UK

)

0

20

40

60

80

100

120

140

160

Incr

ea

se %

Simulationconstant speeds

3rd.

4th.

5th.

With manual

With IVT

Gear

Perbury Engineering Ltd.

MPG (UK)

% % Perbury

FTP 65.6 64.1 63.3 60.8 59.6 57.3 75.8 20.3 27.2 91.0

HWFET 89.9 79.0 84.8 76.6 79.0 81.1 101.9 20.2 29.0 122.4

US06 n/a 52.3 54.8 48.5 46.1 51.7 60.4 10.2 31.0 72.5

SC03 n/a 62.7 55.5 56.1 54.2 52.9 68.8 24.0 26.9 82.6

MPG at a constant 60 MPH 90.3 108.5

65 MPH 83.1 99.8

Official Combined MPG 94.8

MPG (US) Predictions for Perbury IVT

Drive Cycle

Pubd

DataNREL Test

Honda Simulation Results

HybridFolsom

CVT Manual Auto Perbury

Increase

Perbury

Perbury Engineering Ltd.

How to increase miles per gallon

ONLY AN IVT CAN DO ALL THIS AND STILL BESMOOTHLY DRIVABLE

Reduce engine speeds by high vehicle gearing

For a given transmission, select the final drive ratioto suit the vehicle speeds during bypass

After attaining maximum overdrive,bypass the rolling assembly

Keep to a chosen engine optimum linebut allow for transient departures

Perbury Engineering Ltd.

Changing from fixed ratios to IV can indeed increase MPG

An additional benefit - cars and traffic can be quieter as well

Simulation increases are approximately 20% better than the Honda Insight Hybrid and 30% better than the 5-speed manual

Even greater increases than this seem to be possible

Conclusions