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Fuel consumption model for buses considering bus route and passenger load variations

Caixia Yang and Eric Bibeau University of Manitoba

Tom MolinskiManitoba Hydro

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Introduction Motivations and objectives Data description, processing and analysis

Fuel consumption model Simulation results Model validations and discussions Conclusions and discussions

Presentation outline

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Air pollution has negative impacts on public health and our environment.

In Canada, the transportation sector is the 2nd largest energy user and the 2nd largest source of greenhouse gas (GHG) emissions that lead to climate change.

Most transit buses are diesel powered in North American.

Introduction

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Diesel fuel expense contributes to transit service’s operational cost.

Electrification of transit buses can reduce exhaust emission and improve fuel economy.

Modelling and simulation of electric powertrain topologies for transit buses. depend on transit bus duty cycles.

Introduction

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Most models on fuel consumption and emission are based on standard or pre-defined driving cycles.

The Altoona Bus Research and Testing Center tests bus fuel consumption and emission using Transit Coach Operating Duty Cycle—3 Central Business District cycles, 2 Arterial cycles, and 1 Commuter cycle.

Introduction

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Transit buses usually provide service along predetermined routes following planned schedules.

They are frequently operated in stop and go patterns.

Therefore, actual buses’ fuel consumption and emission are very different with the reported values conducted on dynamometer in the laboratory over standard driving cycle.

Motivations and objectives

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As discussed in the literatures, the driving cycle should reflect the actual buses’ operational conditions.

Specific driving cycle needs to be developed for estimating Winnipeg Transit fuel consumption and emission.

Therefore, there is a need to generate more complete dataset for bus electrification.

Motivations and objectives

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Data Description

Climate Information Data Subset Itinerary Data Subset Utilization Data Subset Binary-formatted Data Subset Transit Service Routes Data Subset

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Climate Information Data SubsetClimate information will help us estimate bus’s fuel consumption and electrical travel range due to air-conditioner usage during winter and summer seasons.

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Itinerary Data Subset

This data subset is generated by Winnipeg Transit for service planning including service routes, sequence bus stops and locations, travel distance between two bus stops, and operating date.

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Winnipeg transit service areas with seven transit stations’ locations generated based on latitude and longitude of all bus stops selected from itinerary data and seven transit stations

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Utilization Data Subset

This data subset was collected from 82 buses equipped with APC system operating along 124 testing routes.

The bus location, date and time are recorded by GPS receiver in a second by second basis.

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Data Collection

Data were collected from 82 buses operated along 124 testing routes including school and work service routes.

These buses are equipped with Infodev automatic vehicle localization system and automatic passenger counting (APC) system.

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Basic system installation:

Basic data collection method:

APC system, data collection and transmission system

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This data subset is collected from 545 diesel buses along 89 routes over thirteen months starting from January 2010 to January 2011.

Binary-formatted Data Subset

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This data subset is generated based on available information.

It provides 89 service routes information.

This data subset is valuable for finding charging locations and available charging time, which is necessary when convert diesel bus to plug-in electric bus.

Service Routes Data Subset

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(1) 3 free downtown shuttle routes(2) 28 downtown routes(3) 29 express routes (4) 5 crosstown routes(5) 20 regular suburban routes(6) 4 demand-responsive suburban routes

Winnipeg Transit Service Routes

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Distribution of Winnipeg Transit routes with service time for

(a) Weekdays

(b) Saturdays

(c) Sundays/holidays

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Simulate fuel consumption of selected representative routes considering service route information, bus models, and passenger load variation

Calculate overall average fuel consumption considering weight factors of each representative route

Determine average daily consumed fuel

Fuel consumption model

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Fuel consumption model 1Fuel consumption of representative service

routes(1)

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(1) 3 free downtown shuttle routes(2) 28 downtown routes(3) 29 express routes (4) 5 crosstown routes(5) 20 regular suburban routes(6) 4 demand-responsive suburban

routes

Winnipeg Transit Service Routes

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Parameters used in power and energy simulation and fuel

consumption model

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Average fuel consumption:

where ci stands for coefficient factors of the six representative routes, Fueli represent fuel consumption values of the six representative service routes calculated from Equation 1.

)(1

i

n

iiAverage FuelcFuel

(2)

Fuel consumption model 2

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where FuelAverage stands for average fuel consumption calculated from Equation 2, DistanceDailyAverage stands for average daily travel distance of each bus.

(3)

Fuel consumption model 3

Daily average consumed fuel:

geDailyAveraAverage

geDailyAvera

FuelFuel Distance

100

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Simulation results

Fuel consumption of representative service routes:

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Simulation results

Average overall fuel consumption:

Daily average consumed fuel:

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Dataset Application for Fuel consumption modelling

The generated dataset is applied to Winnipeg Transit bus fuel consumption model developed by Yang and Bibeau [6].

Route 1 operated on September 17, 2010 is selected as an example.

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Route #1 service route with 30 stops

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0 1000 2000 30000

2

4

6

8Travel Distance vs Time Profile

Time (Second)

Daily B

us T

ravel dis

tance (

km

)

0 1000 2000 30000

20

40

60

80Speed vs Time Profile

Time (Second)

Bus S

peed (

kph)

0 1000 2000 3000-4

-2

0

2

4Acceleration vs Time Profile

Time (Second)

Bus A

ccele

ration (

m/s

2 )

0 2 4 6 80

5

10Fuel Consumption vs Travel Distance Profile

Bus Travel distance (km)

Fuel C

onsum

ption (

lite

r)

Travel distance, speed, acceleration and fuel consumption of bus 911 (1996 D30LF) for Route #1 with 15 passenger load on September 17, 2010

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Discussions

The possible reasons include: Different number of bus stops: Central business district cycle 4 stops/ km Winnipeg 7 stops/km

Different frequency of stop-and- go: Bus needs to stop on red lights, or at stop signs, or wait for pedestrians cross the road.

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The proposed model includes information on the transit bus, operating speed, environmental factors, and passenger load variations.

Fuel consumption analysis is conducted over multiple driving cycles for six representative Winnipeg Transit service routes from six different categories.

Conclusions

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We validate the proposed model through standard test reporting data and real operation estimations made by Winnipeg Transit.

The results demonstrate that the proposed model provide much improved accurate and reliable fuel consumption estimation than standard testing.

Conclusions

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Conclusions When applying the proposed model to other

locations, appropriate analysis of operation data and selection of the representative driving cycles are required.

Accurate estimation of fuel consumption by a valid simulation model will benefit analysis of the battery size and charging station required for plug-in-hybrid electric buses.

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Reference1. Cleaning the air in Canadian cities, Environment

Canada 20072. Energy efficiency trends in Canada 1990-2008,

Office of Energy Efficiency, Natural Resources Canada

3. Energy use data handbook 1990-2008, Office of Energy Efficiency, Natural Resources Canada

4. Transportation in Canada 2010-an overview, Transport Canada TP 14816

5. A. Esteves-Booth, T. Muneer, H. Kirby, J. Kubie, and J. Hunter, “The measurement of vehicular driving cycle within the City of Edinburgh,” Transp. Res. Part D, 6(3), pp. 209–220, May 2001.

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Reference6. Bus test reports on New Flyer buses D40, D40LF,

D30LF, Bus Testing and Research Center 7. C. Yang and E. Bibeau, “Fuel consumption

simulation model for transit buses based on real operating condition under cold weather to assist bus electrification,” SAE Technical Paper 2012-01-0651, SAE World Congress 2012, Detroit, MI. DOI: 10.4271/2012-01-0651 Funding: NSERC-IRC.

8. Standard driving cycles for buses, available at http://www.dieselnet.com/standards/cycles

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Acknowledgments

NSERC/Manitoba Hydro Industrial Chair

Bill Menzies Steven J. Brandson Phil Wiwchar

Soheil Shahidinejad Ali Ashtari

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Thank you!

Questions?