Title of Invention

AN ENGINE CONTROL SYSTEM FOR ESTIMATING FUEL CONSUMPTION THAT COMPENSATES FOR THE FUEL ETHANOL PERCENT

Abstract An engine control module determining an alcohol compensated fuel consumption value includes an alcohol percent module that determines an alcohol percent in fuel and a fuel mass module that determines a mass of the fuel. The engine control module also includes a fuel volume module that calculates a volume of the fuel based on the mass of the fuel, a density of the fuel, and the alcohol percent.
Full Text 1
ETHANOL COMPENSATED FUEL DENSITY FOR
FUEL CONSUMED CALCULATION
FIELD
[0001] The present disclosure relates to engine systems, and more
particularly to a system and method for estimating fuel consumption that
compensates for the fuel ethanol percent.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not constitute prior art.
[0003] Flexible fuel vehicles (FFVs) are designed to run on a variety
of fuels, for example: gasoline, alcohol/gasoline blends, such as 85% ethanol
(E85), or a combination of gasoline and alcohol/gasoline blends that result in
a random fuel alcohol percent. An engine operating on an alcohol/gasoline
blend requires an increased amount of fuel in an air-to-fuel (A/F) ratio
compared to gasoline at stoichiometry. For instance, at stoichiometry, the
E85 A/F ratio is near 9:1, while gasoline's A/F ratio is near 14.5:1.
[0004] Traditionally, "fuel consumed" and "average fuel economy"
data are displayed in many vehicles on a Driver Information Center (DIC).
Fuel consumption volume may be determined by dividing the mass of fuel
consumed by its density. In the past it has been possible to use a fixed fuel
density value to calculate the consumption of fuel due to the narrow range of
possible density values available. Traditionally, an average fuel density of
approximately 735,000 mg/liter was used regardless of the density of the fuel
actually being consumed. However, calculating fuel consumption for FFVs
based on an average fuel density of gasoline, may result in inaccurate fuel
consumption values because the density of ethanol is 8-10% higher than
gasoline.

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[0005] When a driver refuels an FFV, fuel alcohol percent may
change significantly with the addition of new fuel. For example, E85 or
gasoline may be introduced into a fuel tank containing gasoline or some
alcohol/gasoline blend, potentially resulting in a new fuel alcohol percent. A
change in the fuel alcohol percent results in a change in fuel density. Using a
fixed fuel density suitable for either gasoline or E85 may lead to an
underestimated or overestimated average fuel economy value. For instance,
a fuel density set for E85 will result in an overestimated average fuel economy
when the engine is operating on lower density gasoline, and a fuel density set
for gasoline will result in an underestimated average fuel economy when the
engine is operating on higher density E85. Further, neither will be accurate
when the alcohol/gasoline blend is somewhere between 100% gasoline and
100% E85.
SUMMARY
[0006] An engine control module determining an ethanol
compensated fuel consumption value includes an alcohol percent module that
determines an alcohol percent in fuel and a fuel mass module that determines
a mass of the fuel. The engine control module also includes a fuel volume
module that calculates a first volume of fuel based on the mass of the fuel, the
fuel density and the alcohol percent of the fuel.
[0007] The fuel volume module may also add the first fuel volume to
a second volume of fuel that is an accumulated volume of the fuel. The fuel
volume module generates a fuel consumed value and an average fuel
economy value for a DIC based on the first fuel volume and the second fuel
volume.
[0008] A method of measuring a first volume of fuel consumed in an
engine includes determining a mass of fuel consumed by the engine, and
determining an alcohol percent in fuel. The method calculates the first volume
of fuel based on fuel mass, a density of the fuel and the alcohol percent.

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[0009] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the description and
specific examples are intended for purposes of illustration only and are not
intended to limit the scope of the present disclosure.
DRAWINGS
[0010] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present disclosure in any
way.
[0011] FIG. 1 is a schematic of a vehicle having an engine control
module calculating fuel consumption according to the present disclosure;
[0012] FIG. 2 is a diagram of an engine control module operable to
perform consumption of fuel calculation according to the present disclosure;
and
[0013] FIG. 3 is a flow diagram of a method for providing an
improved consumption of fuel calculation according to the present disclosure.
DETAILED DESCRIPTION
[0014] The following description of the preferred embodiment is
merely exemplary in nature and is in no way intended to limit the present
disclosure, its application, or uses. For purposes of clarity, the same
reference numbers will be used in the drawings to identify similar elements.
As used herein, the term module refers to an application specific integrated
circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group)
and memory that execute one or more software or firmware programs, a
combinational logic circuit, or other suitable components that provide the
described functionality.

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[0015] Referring now to FIG. 1, a vehicle 10 is schematically
illustrated. The vehicle 10 may be fueled with gasoline and/or an
alcohol/gasoline blend in various alcohol percentages. The alcohol may be
ethanol. Fuel is delivered to an engine 12 from a fuel tank 14 through a
plurality of fuel injectors 16. The engine 12 includes a plurality of cylinders 18
that receive fuel from the fuel injectors 16 to drive a crankshaft 20.
[0016] An electronic throttle controller (ETC) 22 adjusts a throttle
plate 24 that is located adjacent to an inlet of an intake manifold 26 based
upon a position of an accelerator pedal 28 and a throttle control algorithm that
is executed by an engine control module 30. The position of the throttle 24
provides an output torque command.
[0017] A fuel sensor 32 senses a level of fuel in the tank 14 and
communicates the fuel level to the control module 30. Air is delivered to the
engine 12 through the intake manifold 26. Vapor from the fuel tank 14 may be
collected and delivered to the intake manifold 26 and burned in engine
cylinders 18 as well. The control module 30 controls operation of fuel
injectors 16 and an ignition system (not shown). The control module 30 also
is connected with an accelerator pedal sensor 34 that senses a position of the
accelerator pedal 28 and sends a signal representative of the pedal position
to the control module 30. Other sensor inputs collectively indicated by
reference number 36 and used by the control module 30 include a signal 38
indicating engine speed, a vehicle speed signal 40, an intake manifold
pressure signal 42 and a throttle position signal 44.
[0018] A catalytic converter 46 receives exhaust from the engine 12
through an exhaust manifold 48. An oxygen sensor 50 senses exhaust in the
manifold 48 and delivers signals to the control module 30 indicative of
whether the exhaust is lean or rich. The signal output of the oxygen sensor
50 is used by the control module 30 as feedback in a closed-loop manner to
regulate fuel delivery to the engine 12 via the fuel injectors 16.

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[0019] The control module 30 may in part use the exhaust sensor
50 feedback, and the fuel alcohol percent to drive an actual air-to-fuel ratio to
a desired value, usually around a stoichiometric value. A plurality of
predefined engine operating regions are referred to by the control module 30
in controlling fuel delivery to the engine 12. Operating regions may be
defined, for example, based on speed, the load of the engine 12 and/or the
fuel ethanol percent. The control module 30 may perform control functions
that vary, dependent on which operating region of the vehicle is currently
active.
[0020] A Driver Information Center 52 (DIC) may be periodically
provided with an updated fuel consumed and an updated average fuel
economy data by the control module 30. With an estimated or a measured
alcohol percent, the control module 30 may determine fuel density and
generate updated, alcohol compensated fuel consumed and average fuel
economy values for the DIC 52.
[0021] Referring now to FIG. 2, some elements of the engine control
module 30 are shown. The engine control module 30 includes a fuel mass
module 54 that periodically determines a mass of fuel delivered to the fuel
injectors 16. An alcohol percent module 56 periodically determines an alcohol
percent in the fuel delivered to the fuel injectors 16. The alcohol percent
module 56 may estimate the current alcohol percent or measure it directly. A
fuel volume module 58 receives the fuel mass value generated by the fuel
mass module 54 and the updated alcohol percent value generated by the
alcohol percent module 56. A look-up table 60 returns an estimated fuel
density value to the fuel volume module 58 based on the updated fuel ethanol
percent. The fuel volume module 58 stores the updated, estimated fuel
density value. A preferred embodiment of look-up table 60 uses the following

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table:

Ethanol Percent Density (mg/liter)
0 730,000
10 730,000
20 735,000
50 750,000
80 780,000
[0022] The fuel volume module 58 calculates an alcohol
compensated volume of fuel consumed. The volume of fuel consumed is
calculated by dividing the fuel mass value by the updated fuel density value.
The fuel volume module 58 adds the volume of fuel consumed to an
accumulated volume of fuel consumed to calculate an updated accumulated
volume of fuel consumed. The fuel volume module 58 stores the updated
accumulated volume of fuel consumed. The fuel volume module 58
calculates an average fuel economy value based on the updated volume
consumed and updated accumulated volume values. The updated fuel
consumed and updated average fuel economy values are transmitted to the
DIC 52.
[0023] Referring now to FIG. 3, a flowchart depicts a method 300 for
calculating an alcohol compensated volume of fuel consumed. Method 300
can be implemented as a computer program that is stored in a computer
memory associated with a computer. The computer and computer memory
may be included in the engine control module 30. Method 300 may run
periodically each time the engine is started. In one example, the method 300
runs every 100 msec while the engine is operating.

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[0024] Control begins in start block 302 and proceeds to decision
block 304. In decision block 304, control determines whether a new alcohol
percent value has been received. If a new alcohol percent value has been
received, control proceeds to block 306. If a new alcohol percent value has
not been received, control proceeds to decision block 308.
[0025] In block 306, control uses a look-up table and determines a
new fuel density value based on the new alcohol percent value and an
updated fuel density value is stored. After completing block 306 control
proceeds to decision block 308. In decision block 308 control determines
whether a new fuel mass value has been received. If a new fuel mass value
has been received, control proceeds to block 310. If a new fuel mass value
has not been received, control proceeds to block 304.
[0026] In block 310, control calculates a volume of fuel consumed
value by dividing the new fuel mass value by the stored fuel density value.
After completing block 310 control proceeds to block 312. In block 312,
control adds the volume of fuel consumed value calculated in block 310 to an
accumulated fuel consumed value to determine a new accumulated fuel
consumed value. After completing block 312 control proceeds to block 314.
In block 314 control takes the latest volume of fuel consumed value from
block 310 and the updated accumulated fuel consumed value and generates
the updated fuel consumed value and an average fuel economy value that are
then transmitted to the DIC 52.

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CLAIMS
What is claimed is:
1. An engine control module, comprising:
an alcohol percent module that determines an alcohol percent in
a fuel;
a fuel mass module that determines a mass of said fuel; and
a fuel volume module that calculates a first volume of said fuel
based on said mass, said alcohol percent and a density of said fuel.
2. The engine control module of claim 1 wherein said fuel volume
module adds said first fuel volume to a second fuel volume, that generates a
sum of said first and second fuel volumes, and that generates a first updated
value indicating fuel consumed and a second updated value indicating an
average fuel economy based on said first fuel volume and said sum of said
first and second fuel volumes.
3. The engine control module of claim 2 wherein said fuel volume
module communicates said fuel consumed and average fuel economy values
to a Driver Information Center.
4. The engine control module of claim 1 wherein said alcohol is
ethanol.
5. The engine control module of claim 1 wherein said fuel mass is
measured directly.
6. The engine control module of claim 1 wherein said fuel mass is
estimated.

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7. The engine control module of claim 1 wherein said alcohol
percent is measured directly.
8. The engine control module of claim 1 wherein said alcohol
percent is estimated.
9. The engine control module of claim 1 wherein said fuel density
is determined by accessing a look-up table, correlating said fuel density with
said alcohol percent.
10. The engine control module of claim 1 wherein said first volume
of said fuel is calculated by dividing said mass by said density of said fuel.
11. A method of measuring an alcohol compensated volume of fuel
consumed in an engine, said method comprising:
determining a mass of fuel consumed by said engine;
determining an alcohol percent in said fuel; and
calculating a first volume of said fuel based on said fuel mass,
said alcohol percent, and a density of said fuel.
12. The method of claim 11 wherein said first fuel volume is added
to a second volume of said fuel that is an accumulated volume of said fuel;
wherein a fuel consumed value and an average fuel economy value are
generated based on said first fuel volume and said second fuel volume.
13. The method of claim 11 wherein said alcohol is ethanol.

14. The method of claim 11 wherein said fuel mass is measured
directly.
15. The method of claim 11 wherein said fuel mass is estimated.

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16. The method of claim 11 wherein said fuel percent is estimated.
17. The method of claim 11 wherein said fuel percent is measured
directly.
18. The method of claim 11 wherein calculating a first volume
includes dividing said fuel mass by said density of said fuel.

An engine control module determining an alcohol compensated fuel
consumption value includes an alcohol percent module that determines an
alcohol percent in fuel and a fuel mass module that determines a mass of the
fuel. The engine control module also includes a fuel volume module that
calculates a volume of the fuel based on the mass of the fuel, a density of the
fuel, and the alcohol percent.

Documents:

00310-kol-2008-abstract.pdf

00310-kol-2008-claims.pdf

00310-kol-2008-correspondence others.pdf

00310-kol-2008-description complete.pdf

00310-kol-2008-drawings.pdf

00310-kol-2008-form 1.pdf

00310-kol-2008-form 2.pdf

00310-kol-2008-form 3.pdf

00310-kol-2008-form 5.pdf

18-03-2013-CASH-(18-03-2013)-PETITION UNDER RULE 137.pdf

310-KOL-2008-(07-11-2013)-ABSTRACT_.pdf

310-KOL-2008-(07-11-2013)-ANNEXURE TO FORM 3_.pdf

310-KOL-2008-(07-11-2013)-CLAIMS_.pdf

310-KOL-2008-(07-11-2013)-CORRESPONDENCE_.pdf

310-KOL-2008-(07-11-2013)-DESCRIPTION (COMPLETE)_.pdf

310-KOL-2008-(07-11-2013)-DRAWINGS_.pdf

310-KOL-2008-(07-11-2013)-FORM-1_.pdf

310-KOL-2008-(07-11-2013)-FORM-2_.pdf

310-KOL-2008-(07-11-2013)-OTHERS_.pdf

310-KOL-2008-(18-03-2013)-ABSTRACT.pdf

310-KOL-2008-(18-03-2013)-CLAIMS.pdf

310-KOL-2008-(18-03-2013)-CORRESPONDENCE.pdf

310-KOL-2008-(18-03-2013)-DESCRIPTION (COMPLETE).pdf

310-KOL-2008-(18-03-2013)-DRAWINGS.pdf

310-KOL-2008-(18-03-2013)-FORM 1.pdf

310-KOL-2008-(18-03-2013)-FORM 2.pdf

310-KOL-2008-(18-03-2013)-FORM 3.pdf

310-KOL-2008-(18-03-2013)-OTHERS.pdf

310-KOL-2008-(18-03-2013)-PA.pdf

310-KOL-2008-(18-03-2013)-PETITION UNDER RULE 137.pdf

310-KOL-2008-(26-05-2014)-CORRESPONDENCE.pdf

310-KOL-2008-ASSIGNMENT.pdf

310-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

310-KOL-2008-CORRESPONDENCE OTHERS 1.2.pdf

310-kol-2008-form 18.pdf

310-KOL-2008-GRANTED-FORM 1.pdf

310-KOL-2008-PRIORITY DOCUMENT.pdf

abstract-00310-kol-2008.jpg


Patent Number 261049
Indian Patent Application Number 310/KOL/2008
PG Journal Number 23/2014
Publication Date 06-Jun-2014
Grant Date 30-May-2014
Date of Filing 20-Feb-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 MARK D. CARR 3162 APPLEWOOD TRAIN FENTON, MICHIGAN 48430
2 MICHAEL J. SVESTKA 418 PINELAND TRAIN WATERFORD, MICHIGAN 48327
3 KEVIN J. STORCH 8360 WOODLAND SHORE DRIVE BRIGHTON, MICHIGAN 48114
4 LOUIS A. AVALLONE 701 N. MAIN STREET MILFORD, MICHIGAN 48381
PCT International Classification Number F02D19/00;
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/685,928 2007-03-14 U.S.A.