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FUTURE DIRECTIONS IN POWERTRAIN –LIGHT DUTY PERSPECTIVE
Mike Harpster
Director, Propulsion Systems Research
General Motors
COMMON BASE ENGINE ARCHITECTURE
Top-Rated Truck
Best of the Best
Pickup Truck of the Year
North American
Car and Truck
of the Year
Automobile of the Year
Best of the Best
Performance Car of the Year
Best Resale
Value Top Ten
Hottest New Car of the Year
Car of the Year
10 Best
Fleet Truck
of the YearBest Resale
Value Award
Best Pickup
65
85
105
125
145
165
185
205
225
2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
CO
2 E
mis
sio
ns
on
MV
EG-B
dri
ve c
ycle
(gC
O2
/km
)
Industry Targets normalized to EU drive cycle with units convertedDashed lines indicate proposed (not yet final) regulation
*Canada standard follows U.S.
Mo
re S
trin
gen
t
U.S.*
India
Korea
EU
China
Mexico
10Feb15
Brasil
Saudi Arabia
ENVIRONMENT – GLOBAL FUEL ECONOMYCO2 OUTLOOK
Source:
GM Public Policy
Meeting MY2025 CO2
regulations while delivering vehicles that customers
want and can afford
THE REAL CHALLENGE
Significant US
gasoline price
volatility with a
recent 40% drop
Source: US DOE Energy Information Administration
<5% MY2014 vehicles
meet MY2025 CO2 and all
are advanced powertrains
Source: EPA US Light-Duty
Automotive Technology,
Carbon Dioxide Emissions
and Fuel Economy Trends:
1975 Through 2014
MY
2014 V
ehic
les M
eetin
g C
O2
Reg
Conventional
vehicles are closing
the gap to hybrids
Source: EPA US Light-Duty Automotive
Technology, Carbon Dioxide Emissions, and
Fuel Economy Trends: 1975 Through 2014
~24 mpg ~15 mpg
Source: US DOE Energy Information Administration
Annual Energy Outlook 2014
0
2
4
6
8
10
12
14
16
18
2011 2013 2015 2017 2019 2021 2023 2025
US New Vehicle Sales by Propulsion System Technology Type (millions)
FCEV
BEV
PHEV
LPG
CNG
TDI Diesel
HEV
Conv Gas
Conventional gasoline
vehicles forecasted to
dominate US sales
US New Vehicle Sales by Propulsion System Type (millions)
CONVENTIONAL VEHICLES WILL PLAY A ROLE
MEGATRENDS FOR FUTURE POWERTRAINS
ELECTRIFICATIONEFFICIENCY IMPROVEMENTS
SOURCE OF ENGINE CO2 REDUCTION
Engine Focus Minimize pumping losses (VVA , downsizing/AFM, dilute combustion)
Minimize parasitic losses (variable speed/displacement pumps)
Minimize friction losses (low friction piston/bore interface, downsizing)
Maximize work extraction (dilute combustion, waste heat recovery)
Improved Fuels
Vehicle/Powertrain Integration Focus Simultaneously solving the transmission, engine
and vehicle equation to minimize CO2
Maximizing engine-off operation
Active thermal management
Intelligent electrification
Connected and autonomous vehicles
Time
Op
po
rtu
nit
y
Powertrain System Focus Wider transmission ratio spreads with small or infinite
steps to enable efficient engine operation
Advanced dampers enabling down-sized boost engines
and cylinder deactivation
0%
100%
¶ GM is studying dilute combustion concepts to maximize efficiency
¶ The physics say air dilution offers greater benefits that EGR but the required lean aftertreatment has significant challenges (e.g. cost)
Stoichiometricw/o EGR
Stoichiometric w/ EGR
Lean w/ EGR
Isentropic
Indicated
13%3%
DILUTE COMBUSTION
FUELS – OPTIMIZED FOR SI COMBUSTIONIncreasing RON allows increased downsizing and/or
compression ratio and thus engine efficiency
FUELS – OPTIMIZED FOR LOW TEMPERATURE COMBUSTION
Octane Index (OI = RON – K*Sensitivity) is a good measure of fuel performance when
“K” is adjusted to the engine/combustion mode
Easy to Ignite
Hard to Ignite
0
2
4
6
8
10
12
14
16
18
20
72 74 76 78 80 82 84 86
CA
50 @
NV
O =
130
Octane Index with K = 2
RON = 100
Sensitivity = 13 RON = 90
Sensitivity = 3
Sensitivity = (RON-MON)
Data based on 7 full blend gasoline fuels
SOURCE OF ENGINE CO2 REDUCTION
Engine Focus Minimize pumping losses (VVA , downsizing/AFM, dilute combustion)
Minimize parasitic losses (variable speed/displacement pumps)
Minimize friction losses (low friction piston/bore interface, downsizing)
Maximize work extraction (dilute combustion, waste heat recovery)
Improved Fuels
Vehicle/Powertrain Integration Focus Simultaneously solving the transmission, engine
and vehicle equation to minimize CO2
Maximizing engine-off operation
Active thermal management
Intelligent electrification
Connected and autonomous vehicles
Time
Op
po
rtu
nit
y
Powertrain System Focus Wider transmission ratio spreads with small or infinite
steps to enable efficient engine operation
Advanced dampers enabling down-sized boost engines
and cylinder deactivation
0%
100%
WE NEED TO SELECT THE RIGHT TRANSMISSION FOR THE SPECIFIC APPLICATION
Example: 3-cylinder Turbo Study
Transmission Energy (kJ) Loss
(= Pump + Trans Spin + Gear Efficiency + Shift Efficiency + Shift Energy + Torque Converter)
Co
mp
os
ite
Fu
el
Co
ns
um
pti
on
gC
O2/m
ile)
CVT
Step Gear
Trans A
Trans B
CVTA
CVTB
Step gear transmissions are
mechanically efficient…
…but CVT has better CO2
performance due to ratio capability
For this application, CVT is the
preferred technology
ENGINES DRIVING TRANSMISSIONS EVOLUTION
1000 2000 3000 4000 5000 6000-50
0
50
100
150
200
250
300
240240
250250
250
260260
260
280 280280
300 300300
340 340340
400 400 400
500 500 500
700 700 7001000 1000
Engine Speed (RPM)
Bra
ke
To
rqu
e (
Nm
)
BSFC (g/kW-hr)
1000 2000 3000 4000 5000 6000-50
0
50
100
150
200
250
300
185
185
19
0
190
19
5
195
195
20
0
200
200
20
5
205
205
210
210
210
215
215
215
220
220
220230
230
230
240
240
240
250
250
250
260
260
260
280
280
280
300300
300
340340
340
400400
400
500 500500
700 700 7001000 1000 1000
Engine Speed (RPM)
Bra
ke
To
rqu
e (
Nm
)
BSFC (g/kW-hr)
Today’s Engine Maybe Tomorrow’s Engine
BSFC (g/kW-hr) BSFC (g/kW-hr)
Engine Speed (RPM) Engine Speed (RPM)
Bra
ke
To
rqu
e (
Nm
)
Bra
ke
To
rqu
e (
Nm
)
¶ The engines of tomorrow may look very different than today’s engines
¶ As the engine “transformer”, transmissions are likely impacted
¶ Need to optimize at the propulsion system level to maximize overall value
SOURCE OF ENGINE CO2 REDUCTION
Engine Focus Minimize pumping losses (VVA , downsizing/AFM, dilute combustion)
Minimize parasitic losses (variable speed/displacement pumps)
Minimize friction losses (low friction piston/bore interface, downsizing)
Maximize work extraction (dilute combustion, waste heat recovery)
Improved Fuels (high RON, high sensitivity)
Vehicle/Powertrain Integration Focus Simultaneously solving the transmission, engine
and vehicle equation to minimize CO2
Maximizing engine-off operation
Active thermal management
Intelligent electrification
Connected and autonomous vehicles
Time
Op
po
rtu
nit
y
Powertrain System Focus Wider transmission ratio spreads with small or infinite
steps to enable efficient engine operation
Advanced dampers enabling down-sized boost engines
and cylinder deactivation
0%
100%
POWERTRAIN/VEHICLE BANDWIDTH
Vehicle bandwidth for a given engine (TWC, RL, Grade, 0-60)
Be
tte
rC
O2
Pe
rfo
rma
nce
Biggest CO2 Impact
Sub-optimization
MEGATRENDS FOR FUTURE POWERTRAINS
ELECTRIFICATIONEFFICIENCY IMPROVEMENTS
ELECTRIFICATION SOLUTIONSREDUCE CONSUMPTION & DISPLACE PETROLEUM
CONSERVATION DISPLACEMENT
Petroleum and Biofuels(Conventional and Alternative Sources)
Increasingly Electrified Propulsion Systems
Electricity(Zero Emissions Energy Sources)
Light ElectrificationExtended-Range
ElectricBattery Electric
HEVPHEV
2016 Chevrolet Volt
50 miles of EV range
400 miles of total driving range
IMPACT OF ELECTRIFICATION ON POWERTRAINS
The Volt is a great example of the impact of electrification
Volt has to operate efficiently in two modes of operation:
EV Mode with energy coming from the battery and motors
Extended Range Mode with energy coming from the engine
Engine Speed (RPM)
En
gin
e T
orq
ue
(N
m)
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000
50
100
150
200
250
300
350
400
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.36
0.35
0.30
Radically different capabilities drive significantly different transmissions Electric motor’s advantage over the engine:¶ ~60% More speed range¶ ~2.6x More torque and available down to near zero speed¶ Broad efficiency islands with up to 93% peak efficient (vs 37.5% for engine)
Engine Map(2016MY Volt)
Motor + Inverter Map(2015MY Volt)
EREV ENGINE VERSUS ELECTRIC MOTOR
VEHICLEINTELLIGENCE
Mechanical76%
Electronics13%
Other9%
Software2%
TECHNOLOGY INNOVATIONVALUE OF ELECTRONICS AND SOFTWARE
$400
20 ECUs
1M lines of code
$1,200
75 ECUs
100M lines of code
2000 Today
Mechanical55%
Electronics24%
Other8%
Software13%
CADILLACSUPER CRUISE
=+Sensor
Fusion
System
3 Short-Range Radars
1 Long-Range Radar
1 Front Camera
8-10 Ultrasonic
Sensors
1 Rear Camera
2 Short-Range Radars
HOW IT WORKS
LANE FOLLOWING: Using a combination of GPS
and optical cameras, Super Cruise watches the
road ahead and adjusts steering to keep the car in
the middle of its lane.
COLLISION AVOIDANCE: A long-distance radar
system detects vehicles more than 300 ft. ahead.
The vehicle will automatically accelerate or apply the
brakes to maintain a preset following distance.
ACTIVE SAFETY
AUTOMATEDSTEERING & LANE
FOLLOWING
CADILLAC TO INTRODUCE SUPER CRUISE IN A NEW 2017 MODEL
VEHICLECONNECTIVITY
9th International CTI Symposium North America 2015, Novi, Michigan
- Mike Harpster, GM Propulsion Systems Research -
VEHICLE CONNECTIVITY:GM SPEEDS UP WITH ONSTAR 4G LTE
Built-in Wi-Fi hotspot
Connect multiple mobile devices at once
Faster, more reliable connection
Connect to vehicle remotely
On more than 30 GM vehicle models
9th International CTI Symposium North America 2015, Novi, Michigan
- Mike Harpster, GM Propulsion Systems Research -
V2X TO DEBUT ON 2017 CADILLAC CTS
Technology allows cars to communicate with each other (V2V), the infrastructure (V2I), and pedestrians (V2P)
9th International CTI Symposium North America 2015, Novi, Michigan
- Mike Harpster, GM Propulsion Systems Research -
WHAT DOES THIS MEAN TO THE POWERTRAIN?
Information about surrounding vehicles and infrastructure
The ability to manipulate vehicle operation when the driver has transferred control
Route Information
Access to information and computational power outside of the vehicle
9th International CTI Symposium North America 2015, Novi, Michigan
- Mike Harpster, GM Propulsion Systems Research -
SUMMARYGlobal convergence of CO2 regulations will drive unprecedented scale opportunities for fuel economy enabling technologies
Conventional powertrain technologies still have a significant potential for fuel economy improvements
Engine innovation will be as part of a powertrain system solution and will be significantly impacted by:
– Engine evolution
– Powertrain electrification
– Greater on-vehicle access to information
– More automated driving
Must keep the customer at the “center”
– In the end, our customers will decide based on what they want and can afford
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