Information
-
Patent Grant
-
6575144
-
Patent Number
6,575,144
-
Date Filed
Tuesday, July 31, 200123 years ago
-
Date Issued
Tuesday, June 10, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Wolfe; Willis R.
- Huynh; Hai
Agents
- Buckert; John F.
- Lippa; Allan J.
-
CPC
-
US Classifications
Field of Search
US
- 123 380
- 123 491
- 123 465
- 123 478
- 123 494
- 123 488
- 701 207
- 701 213
- 701 115
- 701 117
- 701 118
- 701 209
- 701 103
- 701 104
-
International Classifications
- G06F1900
- B60T718
- F02M5100
-
Abstract
A method is provided for controlling an internal combustion engine in a vehicle. The method includes adjusting a fuel injection amount during engine crank based on a barometric pressure. The barometric pressure is determined from at least one signal received from at least one transmitter external from the vehicle.
Description
FIELD OF THE INVENTION
The invention relates to a control system and method for controlling a fueling amount of an engine during engine crank. More particularly, the invention relates to a control system and method that delivers a fuel injection amount during engine crank based on a barometric pressure determined from signals received from a global positioning system.
BACKGROUND OF THE INVENTION
Known engines have long utilized open loop air-fuel control during engine crank when the engine is being started. In particular, an engine controller generally utilizes either a measured or estimated cylinder air charge (lbs. of air/cylinder) and a desired air-fuel ratio to determine a fuel injection amount (lbs. of fuel/cylinder) during engine crank.
Known engine control systems have also utilized mass air flow (MAF) sensors in the throttle body of an engine to determine the cylinder air charge. However, during engine crank, MAF sensors may not provide accurate measurements of mass air flow because the airflow rate is at a lower measurable range of the sensor. Thus, to determine the cylinder air charge during engine crank, known systems have utilized the engine speed, an intake throttle position, and a stored estimated barometric pressure to calculate the cylinder air charge, instead of utilizing the MAF sensor output signal.
The stored estimated barometric pressure value, however, is only updated when the engine is operated at high engine speeds and/or large intake throttle openings when an accurate estimated barometric pressure can be determined. When the vehicle is driven from a low altitude to a relatively high altitude with respect to sea level, the stored barometric pressure may not be updated if high engine speeds and/or large throttle openings are not obtained. Thus, when the engine is stopped and thereafter enters engine crank, the stored barometric pressure may have a large error with respect to the actual barometric pressure. Thus, because the cylinder air charge is determined based on the inaccurate stored barometric pressure, the cylinder air charge may have a large error with respect to the actual inducted cylinder air charge. In this case, the estimated cylinder air charge would be greater than the actual cylinder air charge. Thus, a greater amount of fuel than needed for stoichiometric combustion (i.e., a rich air-fuel mixture) would be injected into the engine cylinder, which may result in a “long start” condition or a “no start” condition of the engine. Further, the rich air-fuel mixture may result in increased hydrocarbon (HC) emissions from the engine and decreased fuel economy.
In order to obtain more accurate estimates of cylinder air charge during engine crank mode, other known systems have added a pressure sensor to measure the barometric pressure. However, adding the pressure sensor increases assembly time, component costs, and warranty costs.
SUMMARY OF THE INVENTION
The invention relates to a control system and method that delivers a predetermined fuel injection amount, based on a barometric pressure determined from signals received from an external source. The external source may comprise a global positioning system, a communication satellite, or a land-based communication station that transmits either position indicative signals or other signals indicative of the barometric pressure. The inventive method is preferably utilized during engine crank. However, the inventive method may also be utilized during closed loop air-fuel control of the engine after engine crank has been completed.
The method for controlling an internal combustion engine in a vehicle in accordance with first aspect of the present invention includes adjusting a fuel injection amount during engine crank based on an ambient barometric pressure, the barometric pressure determined from at least one signal received from at least one transmitter external from the vehicle. The signals may comprise signals that are indicative of an altitude of the vehicle. The altitude can be utilized to determine the barometric pressure based on a known relationship between altitude and barometric pressure. Alternately, the signals may be indicative of latitudinal and longitudinal position of the vehicle. The latitudinal position and longitudinal position may be correlated with stored elevational information to determine the altitude of the vehicle, and, the altitude may be used to calculate the barometric pressure as described above. Alternately, the latitudinal and longitudinal position may be correlated with stored barometric pressure information to determine the associated barometric pressure.
The control system for an internal combustion engine in accordance with a second aspect of the present invention includes a receiver receiving at least one signal from at least one transmitter external from the vehicle, the signal being indicative of barometric pressure. The control system further includes a controller operably connected to the receiver, the controller adjusting a fuel injection amount in the engine during engine crank responsive to the barometric pressure.
The control system and method for controlling an internal combustion engine in accordance with the present invention provides a substantial advantage over conventional systems and methods. When a receiver, such as a GPS receiver, is already installed in a vehicle, the method may accurately determine the barometric pressure based on at least one signal received from a global positioning system. Thus, an additional pressure sensor that would ordinarily be utilized to determine barometric pressure can be omitted from the vehicle. Further, once the barometric pressure is determined, the barometric pressure can be utilized to control a fuel injection amount during various engine operating conditions including engine crank. Because GPS signals allow for accurate barometric pressure readings to be calculated, the cylinder air charge and the fuel injection amount, determined based on the barometric pressure, can also be accurately determined. Thus, the inventive control system and method solves the potential problems of “no start” or “long start” conditions during engine crank at high altitudes due to an inadvertent rich air-fuel mixture being injected into the engine cylinders because of an inaccurate barometric pressure estimate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic of an automotive vehicle having a receiver for receiving signals from a global positioning system and/or a land-based communication station in accordance with the present invention.
FIG. 2
is a schematic of an engine control system in accordance with the present invention in conduction with a conventional engine.
FIGS. 3A-3E
are flowcharts of a method of controlling an internal combustion engine in accordance with the present invention.
FIG. 4
is a table of altitude and barometric pressure values that may be utilized by the inventive method.
FIG. 5
is a graph illustrating a table of latitudinal, longitudinal and altitude values that may be utilized by the inventive method.
FIG. 6
is a graph illustrating a table of latitudinal, longitudinal and barometric pressure values that may be utilized by the inventive method.
FIG. 7
is a schematic illustrating a communication station that can communicate with a vehicle in accordance with the present invention.
DESCRIPTION OF EMBODIMENTS
Referring now to the drawings, like reference numerals are used to identify identical components in the various views. Referring to
FIG. 1
, an automotive vehicle
10
is shown having a receiver
12
and an optional transceiver
14
. The receiver
12
can be any conventional receiver capable of receiving electromagnetic signals from a suitable transmission system wherein geographic position and/or altitude can be determined. In a preferred embodiment, the receiver
12
receives radio frequency signals, indicative of position and/or altitude of vehicle
10
, from a global positioning system
16
. The operation of an optional transceiver
14
, the communication satellite
18
, and the land based communication station
20
will be described in greater detail below.
The global positioning system
16
may comprise a plurality of GPS satellites
22
,
24
,
26
,
28
orbiting earth. Currently, there are 24 such satellites positioned above North America. The satellites
22
,
24
,
26
,
28
continuously transmit radio frequency signals that are utilized to determine a geographic position on Earth. Generally, signals from at least three satellites may be utilized to determine longitudinal and latitudinal position of a receiver. Further, signals from at least four satellites may be utilized to determine an altitude of the receiver.
In Europe, a similar satellite based system, GLONAS, also operates in a similar manner as compared with the GPS system utilized in North America. Thus, in an alternate embodiment, the receiver
12
could be a GLONAS receiver that can determine position and altitude based upon signals received from the GLONAS satellites.
Referring to
FIG. 2
, the vehicle
10
is shown which includes an internal combustion engine
30
and an engine control system
32
.
The engine
30
comprises a plurality of cylinders, one cylinder of which is shown in FIG.
2
. Engine
30
further includes a combustion chamber
34
, cylinder walls
36
, a piston
38
, a crankshaft
40
, a spark plug
42
, an intake manifold
44
, an exhaust manifold
46
, an intake valve
48
, an exhaust valve
50
, a throttle body
52
, a throttle plate
54
, a fuel injector
56
, and a catalytic converter
58
.
Combustion chamber
34
communicates with intake manifold
44
and exhaust manifold
46
via respective intake and exhaust valves
48
,
50
. Piston
38
is positioned within combustion chamber
34
between cylinder walls
36
and is connected to crankshaft
40
. Ignition of an air-fuel mixture within combustion chamber
34
is controlled via spark plug
42
which delivers ignition spark responsive to a signal from distributorless ignition system
60
.
Intake manifold
44
communicates with throttle body
52
via throttle plate
54
. Throttle plate
54
is controlled by electric motor
62
which receives a signal from ETC driver
64
. ETC driver
64
receives a control signal (DC) from a controller
66
. Intake manifold
44
is also shown having fuel injector
56
coupled thereto for delivering fuel in proportion to the pulse width of signals (FPW) from controller
66
. Fuel is delivered to fuel injector
56
by a conventional fuel system (not shown) including a fuel tank, fuel pump, and fuel rail (now shown). Although a port fuel injection is shown, a direct fuel injection could be utilized instead of port fuel injection.
Exhaust manifold
46
communicates with catalytic converter
58
which reduces exhaust gases such a hydrocarbons (HC), nitrous oxides (NOx), and carbon monoxide (NO).
Control system
32
is provided to control the operation of the engine
30
in accordance with the present invention. Control system
32
includes distributorless ignition system
60
, an electric motor
62
for controlling the throttle plate
54
, an ETC driver
64
, an exhaust gas sensor
68
, a mass air flow sensor
70
, a temperature sensor
72
, a throttle position sensor
74
, a torque sensor
76
, a turbine speed sensor
78
, a variable reluctance sensor
80
, a pedal position sensor
82
, an accelerator pedal
84
, GPS receiver
12
, an optional transceiver
14
, and controller
66
.
In an alternate embodiment, throttle plate
54
may be directly connected to accelerator pedal
84
by a mechanical linkage or cable.
The distributorless ignition system
60
, electric motor
62
, and ETC driver were discussed above and will not be described in any further detail.
Exhaust gas sensor
68
is conventional in the art and may comprise either an EGO, HEGO, or UEGO oxygen sensor. As illustrated, the sensor
68
is coupled to exhaust manifold
46
upstream of catalytic converter
58
. The sensor
68
may generate a signal EGO responsive to an oxygen concentration in the exhaust gases which is received by the controller
66
.
Mass air flow sensor
70
generates a signal indicating the inducted mass air flow (MAF) which is received by the controller
66
. The sensor
70
is conventional in the art and may be coupled to the throttle body
52
or intake manifold
44
.
Temperature sensor
72
generates a signal indicating the engine coolant temperature (ECT) which is received by the controller
66
. The sensor
72
is conventional in the art and is coupled to the cooling jacket
86
in the cylinder wall
36
.
Throttle position sensor
74
generates a signal indicating a throttle position (TP) of the throttle plate
54
which is received by the controller
66
. Accordingly, sensor
74
provides positional information of the plate
54
for closed-loop control of the plate
54
.
Torque sensor
76
generates a signal indicating the transmission shaft torque or the engine shaft torque (TQ) which is received by the controller
66
.
Turbine speed sensor
78
generates a signal (Wt) indicating the speed of a shaft connected to a turbine (not shown) which is received by the controller
66
.
Variable reluctance sensor
80
generates a variable reluctance signal (VRS) indicating an engine speed (N). In a alternate embodiment, sensor
80
may comprise a hall effect sensor that generates a profile ignition pickup signal (PIP) indicating an engine speed (N). As illustrated the sensor
80
may be coupled to the crankshaft
40
and transmits the signal N to the controller
66
.
Accelerator pedal
84
is shown communicating with the driver's foot
85
. Pedal position sensor
82
generates a signal indicating acceleration pedal position (PP) that is transmitted to the controller
66
.
The GPS receiver
12
is provided to receive signals from GPS satellites
22
,
24
,
26
,
28
and to generate a parameter that is indicative of barometric pressure (BP). The receiver
12
may be connected to the controller
66
via a bi-directional bus
88
. The bus
88
allows the controller
66
to query the receiver
12
for specific information such as vehicle position and/or vehicle altitude based upon the received signals. The receiver
12
is conventional in the art and may comprise any one of a plurality of commercially available GPS receivers. For example, the receiver
12
may comprise an M12 Oncore System manufactured by Motorola, Inc. As discussed below, the vehicle position or altitude can be utilized to determine barometric pressure (BP).
The controller
66
is provided to implement a method in accordance with the present invention. The controller includes a microprocessor
90
communicating with various computer-readable storage media. The computer readable storage media preferably include volatile and nonvolatile storage in a read-only memory (ROM)
92
and a random-access memory (RAM)
94
. The computer readable media may be implemented using any of a number of known memory devices such as PROMs, EPROMs, EEPROMs, flash memory or any other electric, magnetic, optical or combination memory device capable of storing data, some of which represent executable instructions, used by the microprocessor
90
in controlling the engine. The microprocessor communicates with various sensors and actuators (discussed above) via an input/output (I/O) interface
96
. Of course, the present invention could utilize more than one physical controller to provide engine/vehicle control depending upon the particular application.
Referring to
FIG. 3A
, a method
97
for controlling an internal combustion engine
30
in accordance with the present invention is provided. The method may be advantageously utilized during engine crank or during closed-loop air-fuel control of the engine
30
. The method includes a step
98
that determines the barometric pressure (BP) communicating with the vehicle
10
. The step
98
may comprise three alternate methods illustrated in
FIGS. 3B
,
3
C,
3
D for determining the barometric pressure (BP) which will be discussed in greater detail below.
The method further includes a step
100
that determines the cylinder air charge of each of the cylinders of the engine
30
based on the barometric pressure (BP). Those skilled in the art will recognize that there are a plurality of conventional methods that may be utilized to calculate the cylinder air charge based on barometric pressure (BP). For example, the method disclosed in U.S. Pat. No. 6,115,664 entitled “Method Of Estimating Engine Charge”, issued on Sep. 5, 2000, and assigned to the assignee of the present application, which is incorporated herein in its entirety, may be utilized to calculate the cylinder air charge. In particular, U.S. Pat. No. 6,115,664 discloses a method which determines the cylinder air charge based on the barometric pressure (BP), engine coolant temperature (ECT), air charge temperature (ACT), and engine speed (N).
Finally, the method includes a step
102
that calculates the desired fuel pulse width signal (FPW) based on the cylinder air charge, the desired air-fuel ratio, and the signal EGO. As discussed above, the signal (FPW) is utilized to control the fuel injector
56
to inject a desired amount of fuel into the combustion chamber
34
. Further, the cylinder air charge used in step
102
is calculated based on the barometric pressure (BP) determined in step
100
by methods explained in greater detail below. The signal EGO may be utilized by the controller
66
for closed-loop air-fuel control of the engine
30
to improve emission performance of catalyst
58
. Alternately, during open-loop air-fuel control of the engine
30
, the controller
66
may calculate the fuel injection pulse width signal (FPW) based on the cylinder air charge and the desired air-fuel ratio.
Referring to
FIG. 3B
, a first method
105
for determining the barometric pressure (BP) in accordance with the present invention will be discussed. The method includes a step
106
that makes a determination as to whether position indicative signals have been received by the receiver
12
from the global positioning system
16
. In particular, the step
106
may determine whether at least four signals have been received from four corresponding global positioning satellites. When the answer to step
106
equals Yes, the steps
108
,
110
are performed.
The step
108
determines an altitude of the vehicle
10
based on the position indicative signals received from the global positioning system
16
. In particular, the commercially available receiver
12
may determine the altitude of the vehicle
10
based on the received signals. Alternately, the receiver
12
may generate position values based on the received signals and transmit the values to the controller
66
. Thereafter, the controller
66
may calculate the altitude based on the position values utilizing conventional triangulation algorithms known to those skilled in the art.
The step
110
following step
108
determines the barometric pressure (BP) based on the altitude of the vehicle. It is well known that as the altitude of the vehicle increases, the barometric pressure generally decreases according to a known relationship. Referring to
FIG. 4
, for example, a table
112
is shown including altitude values (with respect to Mean Sea Level) in conjuction with corresponding average barometric pressure values at various respective altitudes. The table
112
illustrated in
FIG. 4
may be stored in the nonvolatile memory
92
of the controller
66
. Thus, the controller
66
may access the table
112
to determine the barometric pressure (BP) based upon a determined altitude. It should be understood that when an altitude value (determined from the received signals) falls between the two altitude values in the table
112
, the barometric pressure (BP) may be calculated by interpolating between two corresponding barometric pressures in the table
112
. Alternately, when the altitude is known, the following equation may be utilized by the controller
66
to calculate the barometric pressure (BP):
BP=BP
SL
*(1−6.876E-6*ALT)
5.257
; where BP
SL
=barometric pressure at sea level (14.7 PSI) ALT=altitude of vehicle in feet above sea level
Referring again to step
106
, when position indicative signals from four GPS satellites have not been received by the receiver
12
, the value of step
106
equals No, and the step
112
is performed. The step
112
sets the current value for the barometric pressure (BP) equal to a previously determined barometric pressure (BP
i−1
).
After either of steps
110
,
112
, the method advances to step
100
of the method
97
.
Referring to
FIG. 3C
, a second method
114
for determining the barometric pressure (BP) in accordance with the present invention will be discussed. The method includes a step
116
that makes a determination as to whether position indicative signals have been received by the receiver
12
from the global positioning system
16
. In particular, the step
116
may determine whether at least three position indicative signals have been received from three corresponding global positioning satellites. When the answer to step
116
equals Yes, the steps
118
,
120
,
122
are performed.
The step
118
determines the latitudinal and longitudinal position of the vehicle
10
based on the signals received from the global positioning system
16
. In particular, the commercially available receiver
12
may determine the latitudinal and longitudinal position of the vehicle
10
based on the received signals. Alternately, the receiver
12
may generate position values indicative of the received signals and transmit the values to the controller
66
. Thereafter, the controller
66
may calculate the latitudinal and longitudinal position based on the received position values utilizing conventional methods known to those skilled in the art.
The step
120
determines the altitude of the vehicle
10
based on the latitudinal and longitudinal position and stored elevational information associated with the latitudinal and longitudinal position. Referring to
FIG. 5
, the stored elevational information may comprise a map
124
which includes a Y-axis comprising latitudinal positions and an X-axis comprising longitudinal positions. Further, the map may be divided into grid areas
126
with an average altitude assigned to the specific grid area. Thus, for example, when the position of the vehicle
10
is determined to be within the grid area
128
, the altitude of the vehicle
10
would be approximately 2000 feet MSL (mean sea level). The map
124
illustrated in
FIG. 5
may be stored in the nonvolatile memory
92
of the controller
66
in the form of a table as known to those skilled in the art. Thus, the controller
66
may access the table to determine the altitude based on longitudinal and latitudinal position of the vehicle
10
.
The step
122
following step
120
determines the barometric pressure (BP) based on the altitude of the vehicle
10
. The step
122
may be implemented utilizing substantially the same methodology explained above with reference to step
110
(see FIG.
3
B).
Referring again to step
116
, when position indicative signals from three GPS satellites have not been received by the receiver
12
, the value of step
116
equals No, and the step
130
is performed. The step
130
sets the current value for the barometric pressure (BP) equal to the previously determined barometric pressure (BP
i−1
).
After either of steps
122
,
130
, the method
114
advances to step
100
of the method
97
.
Referring to
FIG. 3D
, a third method
132
for determining the barometric pressure (BP) in accordance with the present invention will be discussed. The method
132
includes a step
134
that makes a determination as to whether position indicative signals from the global positioning system
16
have been received by the receiver
12
. In particular, the step
134
may determine whether at least three position indicative signals have been received from three corresponding global positioning satellites. When the answer to step
134
equals Yes, the steps
136
,
138
are performed.
The step
136
determines the latitudinal and longitudinal position of the vehicle
10
based on the signals received from the global positioning system
16
. The step
136
may be implemented utilizing substantially the same methodology explained above with reference to step
118
of FIG.
3
C.
The step
138
following the step
136
, determines the barometric pressure (BP) based on the latitudinal and longitudinal position of the vehicle
10
and stored barometric pressure information associated with the latitudinal and longitudinal position. Referring to
FIG. 6
, the stored barometric pressure information may comprise a map
142
which includes a Y-axis comprising latitudinal positions and an X-axis comprising longitudinal positions. Further, the map
142
may be divided into grid areas
144
with an average barometric pressure assigned to the specific grid area. Thus, for example, when the position of the vehicle
10
is determined to be within the grid area
146
, the barometric pressure (BP) communicating with the vehicle
10
would be estimated to be 13.6640625 PSI. The map
142
illustrated in
FIG. 6
may be stored in the nonvolatile memory
92
of the controller
66
in the form of a table as known to those skilled in the art. Thus, the controller
66
may access the table to determine the barometric pressure (BP) based on the longitudinal and latitudinal position of the vehicle
10
.
Referring again to step
134
, when position indicative signals from three GPS satellites have not been received by the receiver
12
, the value of step
134
equals No, and the step
140
is performed. The step
140
sets the current value for the barometric pressure (BP) equal to the previously determined barometric pressure (BP
i−1
).
Referring to
FIG. 3E
, an alternate method
148
may be utilized to implement the step
138
of FIG.
3
D. As illustrated, the method
148
may include the steps
150
,
152
,
154
. Referring to
FIGS. 1 and 3E
, in step
150
, an optional transceiver
14
in the vehicle
10
may transmit a signal indicative of the position of the vehicle
10
to a communication station
20
or to a communication satellite
18
. As discussed above, the position of the vehicle
10
may be determined from signals received from a global positioning system
16
. When the transceiver
14
transmits the signal indicative of the vehicle position to the satellite
18
, the satellite
18
may relay the signal to the communication station
20
. Further, a unique vehicle or transceiver identifier code may also be transmitted in the signal to allow the transceiver
158
or computer
156
of station
20
to distinguish between signals from vehicle
10
and signals from other vehicles.
Referring to
FIG. 7
, the communication station
20
will be discussed before completing the explanation of the method
148
. The communication station
20
may be provided to determine a barometric pressure (BP) associated with the vehicle position and communicate the barometric pressure (BP) to the controller
66
of the vehicle
10
, as will be explained in greater detail below. The communication station
20
may include a conventional transceiver
158
for receiving the transmitted vehicle position, a computer
156
, and a barometric pressure database
160
. It should be understood that transceiver
158
could be replaced with a separate transmitter and receiver. The computer
156
may include a microprocessor
162
, a ROM
164
, a RAM
166
, and I/O bus
168
as well known in the art. The barometric pressure database
160
may be operably accessed by the computer
156
and be implemented within the ROM of computer
156
or may comprise an external database as illustrated. Further, the database
160
may comprise a table of real-time barometric pressure readings or recently acquired and/or measured barometric pressure readings associated with specific geographic positions. As discussed above with reference to
FIG. 6
, a barometric pressure (BP) may be associated with a specific grid area or other predefined geographic area or position.
It should be further understood that a plurality of communication stations
20
may be disposed at various geographic locations to provide a transmission/reception coverage area encompassing an entire region, state, country, or continent.
Referring again to
FIG. 3E
, in step
152
, the computer
156
may determine the barometric pressure (BP) by utilizing the position of the vehicle
10
to access a barometric pressure reading stored in the database
160
that is associated with the vehicle position. Next, in step
154
, the computer
156
in conjuction with the transceiver
158
may transmit a second signal indicative of the determined barometric pressure (BP) directly to a transceiver
14
(or receiver) in the vehicle
10
, or to a communication satellite
18
which then relays the signal to the transceiver
14
. The unique vehicle or transceiver identifier code, discussed above, may also be transmitted in the second signal to allow the transceiver
14
or controller
66
to distinguish between signals directed to vehicle
10
and signals directed to other vehicles. As one skilled in the art can recognize, utilizing real-time barometric pressure readings (or recently measured barometric pressure readings) associated with specific vehicle positions could allow enhanced engine control improving fuel economy and reducing emissions.
From the foregoing discussion of methods
105
,
114
,
132
, the latitudinal position and longitudinal position of the vehicle
10
, or the altitude of the vehicle
10
may be determined from a plurality of signals received from the global positioning system
16
. Alternately, the control system
32
could determine the latitudinal position and longitudinal position of the vehicle
10
, or the altitude of the vehicle
10
, from one signal indicative of the foregoing positional information.
The control system
32
and method
97
for controlling an internal combustion engine
30
in accordance with the present invention provide a substantial advantage over conventional systems and methods. In particular, since many vehicle manufacturers are installing GPS receivers
12
in current production vehicles, the receiver
12
may be readily utilized to determine barometric pressure as discussed above, without having to add an additional pressure sensor to the vehicle. Further, the inventive method and system provide for more accurate barometric pressure readings as compared with known methods for estimating the barometric pressure (BP) when no pressure sensor is present in the vehicle. Thus, an engine controller utilizing the more accurate barometric pressure (BP) from the inventive system can determine a more accurate cylinder air charge and fuel injection amount—based on the barometric pressure (BP)—to improve fuel economy and to reduce emissions. Further, the inventive control system
32
and method solves the potential problems of “no start” or “long start” conditions, during engine crank at high altitudes, due to a rich air-fuel mixture being injected in the engine cylinders because of inaccurate barometric pressure estimates.
Claims
- 1. A method for controlling an internal combustion engine of a vehicle, comprising:providing a fuel injection amount during engine crank based on a barometric pressure, and said barometric pressure determined from at least one signal received from at least one transmitter external from said vehicle.
- 2. The method of claim 1 wherein said at least one signal is indicative of longitudinal and latitudinal position of said vehicle, or an altitude of said vehicle.
- 3. The method of claim 1 wherein said at least one transmitter is a global positioning system.
- 4. The method of claim 3 wherein said step of adjusting said fuel injection amount includes:determining an altitude of said vehicle based on said at least one signal received from said global positioning system; and, determining said barometric pressure based on said altitude.
- 5. The method of claim 3 wherein said step of adjusting said fuel injection amount includes:determining a position of said vehicle based on said at least one signal received from said global positioning system; determining an altitude of said vehicle based on said position and stored elevational information corresponding to said position; and, determining said barometric pressure based on said altitude.
- 6. The method of claim 3 wherein said step of adjusting said fuel injection amount includes:determining a position of said vehicle based on said at least one signal received from said global positioning system; and, determining said barometric pressure based on said position and stored barometric pressure information corresponding to said position.
- 7. The method of claim 1 wherein said step of adjusting said fuel injection amount includes:determining a cylinder air charge amount responsive to said barometric pressure; and, determining a desired fuel injection amount based on said cylinder air charge amount.
- 8. The method of claim 1 wherein said barometric pressure is ambient air pressure communicating with said vehicle.
- 9. The method of claim 1 wherein said at least one signal is indicative of barometric pressure and said external transmitter is a communication station transmitter or a satellite transmitter.
- 10. A method for controlling an internal combustion engine of a vehicle, comprising:determining a barometric pressure communicating with said vehicle based on at least one signal received from a global positioning system; and, providing a fuel injection amount in said engine during engine crank responsive to said barometric pressure.
- 11. The method of claim 10 wherein said at least one signal is indicative of an altitude of said vehicle.
- 12. The method of claim 10 wherein said at least one signal is indicative of a longitudinal position and a latitudinal position of said vehicle.
- 13. A method for controlling an internal combustion engine of a vehicle, comprising:determining a barometric pressure communicating with said vehicle based on at least one signal indicative of said barometric pressure received from a communication station or a satellite; and, providing a fuel injection amount during engine crank responsive to said barometric pressure.
- 14. The method of claim 13 wherein said step of determining said barometric pressure includes:transmitting a first signal indicative of a position of said vehicle to a communication station or a satellite; determining said barometric pressure utilizing said position and stored barometric pressure information corresponding to said position; and, transmitting a second signal indicative of said barometric pressure to a receiver in said vehicle from said communication station or said satellite.
- 15. A method for controlling an internal combustion engine, comprising:providing a fuel injection amount in a port fuel injection engine during engine crank based on a barometric pressure, and said barometric pressure determined from at least one signal received from at least one transmitter external from said vehicle.
- 16. A control system for an internal combustion engine, comprising:a receiver receiving at least one signal from at least one transmitter external from said vehicle, said signal being indicative of barometric pressure; and, a controller operably connected to said receiver, said controller providing a fuel injection amount in said engine during engine crank responsive to said barometric pressure.
- 17. The control system of claim 16 wherein said at least one transmitter is a global positioning system.
- 18. The control system of claim 16 wherein said at least one transmitter is a communication station transmitter or a satellite transmitter.
- 19. The control system of claim 16 wherein said at least one signal is indicative of an altitude of said vehicle.
- 20. The control system of claim 16 wherein said at least one signal is indicative of a longitudinal position and a latitudinal position of said vehicle.
- 21. The control system of claim 16 wherein said at least one signal is a barometric pressure signal.
- 22. An article of manufacture comprising:a computer storage medium having a computer program encoded therein for controlling an internal combustion engine, said computer storage medium comprising: code for determining a barometric pressure based on at least one signal received from at least one transmitter external from said vehicle; and, code for providing a fuel injection amount in said engine during engine crank responsive to said barometric pressure.
US Referenced Citations (16)