U.S. patent application number 15/091117 was filed with the patent office on 2017-10-05 for engine start-up method for hybrid vehicle.
The applicant listed for this patent is FORD GLOBAL TECHNOLOGIES, LLC. Invention is credited to Mark G. SMITH.
Application Number | 20170282674 15/091117 |
Document ID | / |
Family ID | 59885673 |
Filed Date | 2017-10-05 |
United States Patent
Application |
20170282674 |
Kind Code |
A1 |
SMITH; Mark G. |
October 5, 2017 |
ENGINE START-UP METHOD FOR HYBRID VEHICLE
Abstract
A vehicle includes an engine, a climate control system, a cabin,
and a controller. The controller is programmed to, in response to
the climate control system supplying heat to a vehicle cabin and
receiving a request for an economy mode, decrease an engine coolant
temperature engine start threshold. The controller is further
programmed to, in response to the engine coolant temperature
becoming less than the threshold, start the engine.
Inventors: |
SMITH; Mark G.; (Canton,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FORD GLOBAL TECHNOLOGIES, LLC |
Dearborn |
MI |
US |
|
|
Family ID: |
59885673 |
Appl. No.: |
15/091117 |
Filed: |
April 5, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60W 10/30 20130101;
B60W 2510/06 20130101; Y10S 903/905 20130101; B60W 2710/06
20130101; B60W 20/40 20130101; B60Y 2306/07 20130101; B60W 20/10
20130101; B60W 20/15 20160101; B60L 2240/36 20130101; B60L 2240/34
20130101; B60H 1/004 20130101; B60Y 2300/43 20130101; B60W 50/082
20130101; B60W 2510/0676 20130101; B60H 1/00764 20130101; B60L
2240/445 20130101; B60W 10/06 20130101; B60K 6/24 20130101; B60L
2260/26 20130101 |
International
Class: |
B60H 1/00 20060101
B60H001/00; B60W 10/30 20060101 B60W010/30; B60H 1/04 20060101
B60H001/04; B60W 20/15 20060101 B60W020/15; B60K 6/24 20060101
B60K006/24; B60W 10/06 20060101 B60W010/06; B60W 20/40 20060101
B60W020/40 |
Claims
1. A vehicle comprising: an engine; a climate control system having
a blower; and a controller programmed to, in response to the
climate control system supplying heat to a cabin via the blower and
receiving a request for an economy mode, decrease an engine coolant
temperature engine start, threshold, cut blower power, and channel
heated ram air into the cabin, and in response to the engine
coolant temperature becoming less than the threshold, start the
engine.
2. The vehicle of claim 1, wherein the controller is further
programmed to, in response to the climate control system supplying
heat to a cabin and receiving a request to terminate the economy
mode, increase the engine coolant temperature engine start
threshold.
3. The vehicle of claim 1, wherein the climate control system
includes a blower that is configured to pump heated air into the
cabin, and wherein the controller is further programmed to reduce a
rate at which the blower delivers heated air into the cabin in
response to the climate control system supplying heat to the cabin
and receiving the request for an economy mode.
4. The vehicle of claim 3, wherein the controller is further
programmed to, in response to the climate control system operating
in a defrost mode, override decreasing the engine coolant
temperature engine start threshold.
5. The vehicle of claim 3, wherein the controller is further
programmed to, in response to the climate control system operating
in a defrost mode, override reducing the rate at which the blower
delivers heated air into the cabin.
6. The vehicle of claim 1, wherein the controller is further
programmed to: in response to the climate control system supplying
heat to the cabin and receiving the request for an economy mode,
decrease an engine coolant temperature engine stop threshold, and
in response to the engine coolant temperature becoming greater than
the engine coolant temperature engine stop threshold, stop the
engine.
7. (canceled)
8. The vehicle of claim 1, wherein the controller is further
programmed to, in response to the climate control system operating
in a defrost mode, override cutting power to the blower and
channeling heated ram air into the cabin.
9. A vehicle controller comprising: input channels configured to
receive signals indicative of a request for cabin heating, a
request for an economy mode, and an engine coolant temperature; a
first output channel configured to provide a command to start an
engine; a second output channel configured to provide a command to
operate a blower to heat a cabin; and control logic programmed to,
in response to the requests for cabin heating and the economy mode,
generate the command to start the engine when the engine coolant
temperature becomes less than a first, threshold, generate the
command to cut power to the blower, and channel heated ram air into
the cabin, and in response to the request for cabin heating and an
absence of the request for the economy mode, generate the command
to start the engine when the engine coolant temperature becomes
less than a second threshold, wherein the second threshold is
greater than the first threshold.
10. The controller of claim 9, further comprising a second output
channel configured to provide a command to operate a blower to pump
heated air into a cabin, and wherein the control logic is further
programmed to, in response to the requests for cabin heating and
the economy mode, generate the command to operate the blower to
deliver heated air into the cabin at a reduced rate that is less
than a desired rate.
11. The controller of claim 10, wherein the control logic is
further programmed to, in response to the request for cabin heating
and the absence of the request for the economy mode, generate the
command to operate the blower to deliver heated air into the cabin
at the desired rate.
12. The controller of claim 11, wherein the control logic is
further programmed to, in response to the request for cabin
heating, the request for the economy mode, and a defrost request,
generate the command to operate the blower to deliver heated air
into the cabin at the desired rate.
13. (canceled)
14. The controller of claim 9, wherein the control logic is further
programmed to, in response to the request for cabin heating, the
request for the economy mode, and a defrost request, generate the
command to start the engine when the engine coolant temperature
becomes less than the second threshold.
15. An engine starting method comprising: in response to a climate
control system supplying heat to a cabin and receiving a request
for an economy mode, starting an engine when the engine coolant
temperature becomes less than a first; threshold, powering off a
blower of the climate control system that delivers heated air into
the cabin, and channeling heated ram air into the cabin; and in
response to an absence of the request for an economy mode, starting
the engine when the engine coolant temperature becomes less than a
second threshold that is greater than the first threshold.
16. The method of claim 15, further comprising: in response to the
climate control system supplying heat to the cabin and receiving
the request for an economy mode, reducing a rate at which a blower
of the climate control system delivers heated air into the
cabin.
17. The method of claim 15, further comprising: in response to the
climate control system supplying heat to the cabin, receiving the
request for an economy mode, and the climate control system
operating in a defrost mode, starting the engine when the engine
coolant temperature becomes less than the second threshold.
18. The method of claim 15, further comprising: in response to the
climate control system supplying heat to the cabin and receiving
the request for an economy mode, activating heated touch points
within the cabin.
19. (canceled)
20. The method of claim 15, further comprising: in response to the
climate control system supplying heat to the cabin, receiving the
request for an economy mode, and the climate control system
operating in a defrost mode, starting the engine when the engine
coolant temperature becomes less than the second threshold and
powering on the blower.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to an engine start-up method
for a hybrid vehicle.
BACKGROUND
[0002] Hybrid vehicles may include both an internal combustion
engine and an electric motor that each provides power to propel the
vehicle. The internal combustion engine may be shut down
periodically, under certain circumstances, while the electric motor
alone provides power in order to increase fuel economy. This may be
referred to as an electric only mode or an EV mode. When the
electric motor alone is incapable of providing the required power
output, the internal combustion engine is started.
SUMMARY
[0003] A vehicle includes an engine, a climate control system, a
cabin, and a controller. The controller is programmed to, in
response to the climate control system supplying heat to a vehicle
cabin and receiving a request for an economy mode, decrease an
engine coolant temperature engine start threshold. The controller
is further programmed to, in response to the engine coolant
temperature becoming less than the threshold, start the engine.
[0004] A vehicle controller includes, input channels, a first
output channel, and control logic. The input channels are
configured to receive signals indicative of a request for cabin
heating, a request for an economy mode, and an engine coolant
temperature. The first output channel is configured to provide a
command to start an engine. The control logic is programmed to, in
response to the requests for cabin heating and the economy mode,
generate the command to start the engine when the engine coolant
temperature becomes less than a first threshold. The control logic
is further programmed to, in response to the request for cabin
heating and an absence of the request for the economy mode,
generate the command to start the engine when the engine coolant
temperature becomes less than a second threshold, wherein the
second threshold is greater than the first threshold.
[0005] An engine starting method includes, in response to a climate
control system supplying heat to a cabin and receiving a request
for an economy mode, starting the engine when the engine coolant
temperature becomes less than a first threshold; and in response to
an absence of the request for an economy mode, starting the engine
when the engine coolant temperature becomes less than a second
threshold that is greater than the first threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic diagram of a hybrid vehicle having a
climate control system; and
[0007] FIG. 2 is a flowchart illustrating an engine start-up method
for the hybrid vehicle.
DETAILED DESCRIPTION
[0008] Embodiments of the present disclosure are described herein.
It is to be understood, however, that the disclosed embodiments are
merely examples and other embodiments may take various and
alternative forms. The figures are not necessarily to scale; some
features could be exaggerated or minimized to show details of
particular components. Therefore, specific structural and
functional details disclosed herein are not to be interpreted as
limiting, but merely as a representative basis for teaching one
skilled in the art to variously employ the embodiments. As those of
ordinary skill in the art will understand, various features
illustrated and described with reference to any one of the figures
may be combined with features illustrated in one or more other
figures to produce embodiments that are not explicitly illustrated
or described. The combinations of features illustrated provide
representative embodiments for typical applications. Various
combinations and modifications of the features consistent with the
teachings of this disclosure, however, could be desired for
particular applications or implementations.
[0009] Referring to FIG. 1, a schematic representative of a hybrid
vehicle 10 having a climate control system 12 is illustrated. The
vehicle 10 includes a powertrain that has an internal combustion
engine 14 and an electric machine 16. The engine 14 and the
electric machine 16 may both generate power to propel the vehicle
10. The electric machine 16 may be a motor or a combination
motor/generator. The powertrain may also include a transmission 18.
The transmission 18 may include a series of selectable gears and
clutches that provide multiple gear ratios between the input and
the output of the transmission. The transmission 18 may be a manual
or automatic transmission. The transmission may also include a
torque converter than may include a locking clutch. The powertrain
may further include a series of shafts that connect the various
elements. For example, the transmission 18 may include an output
shaft 20 that connects to the drive wheels 22 of the vehicle 10 via
a differential 24 and a series of half shafts 26. The electrical
machine 16 may be disposed on an input shaft 28 of the transmission
18. The input shaft 28 may be selectively coupled to a crankshaft
30 of the engine 14 by an engine disconnect clutch 32. The
powertrain may also include other clutches to decouple or couple
various elements. A starter motor 34 may be used to start the
engine 14 or the electrical machine 16 may be used to start the
engine 14 by closing the disconnect clutch 32. A traction battery
36 may provide electrical power to operate the electric machine 16.
The electric machine 16 may in turn recharge the battery when
receiving power from the engine 14 or through regenerative braking
(when being operated as a generator).
[0010] The engine 14 may include a cooling system 38 that utilizes
a liquid coolant to remove heat from the engine 14. The cooling
system 38 may include a first loop 40 that includes a pump 42 and a
first heat exchanger (such as a radiator) 44 to remove excess heat
from the coolant. A fan 46 may be used to direct air across the
first heat exchanger 44 in order to increase the heat transfer from
the liquid coolant within the first loop 40 and the ambient air.
The fan 46 may include an electric motor that provides power to
rotate the blades of the fan 46. The first loop 40 may also include
a thermostat 48 that is configured to bypass the first heat
exchanger 44 and redirect coolant back into the engine 14 when it
is desired to increase the temperature of the coolant.
[0011] The cooling system 38 may also include a second loop 50 that
is configured to direct coolant to a second heat exchanger 52 that
is part of the climate control system 12. The second heat exchanger
52 may be a heater core that transfers heat from the coolant to air
that is being directed into a cabin 54 of the vehicle 10. The
climate control system 12 may include a blower 56 that is
configured to direct air across the second heat exchanger 52 in
order to heat the air entering the cabin 54, when the vehicle
operator has activated the climate control system 12 to heat the
cabin 54. The blower 56 may include an electric motor that provides
power to rotate the blades of the blower 56. The second cooling
loop 50 may include a valve 57 that opens to allow heated coolant
to flow through the second cooling loop 50 when the vehicle
operator has activated the climate control system 12 to heat cabin
54. The valve 57 may be configured to close when the vehicle
operator has not activated the climate control system 12 to heat
cabin 54.
[0012] The climate control system 12 may also include an
air-conditioning system 58. The air-conditioning system may include
a refrigerant loop, 60, a compressor 62, a condenser 64, a
receiver/dryer 66, an expansion valve 68, and an evaporator 70. The
blower 56 may be configured to direct air across the evaporator 70
in order to cool the air entering the cabin 54, when the vehicle
operator has activated the climate control system 12 to cool the
cabin 54. The speed of the blower 56 (whether heating or cooling)
may be a function of the temperature of the ambient air, a heat
load value, cabin temperature, etc. and may range between a maximum
output speed and zero depending on these factors. The selection of
an economy mode (discussed below) may or may not change the blower
speed based the temperature of the ambient air, a heat load value,
cabin temperature, etc. The climate control system 12 may also
include a second fan 72 that is configured to direct air across the
condenser 64 in order to reject excess heat from the refrigerant in
the refrigerant loop 60 to the ambient air. Alternatively, the fan
46 that directs air across the first heat exchanger 44 may also be
used to direct air across the condenser 64 as opposed to using a
second fan 72. The second fan 72 may include an electric motor that
provides power to rotate the blades of the second fan 72.
[0013] The vehicle 10 may also include a controller 74 is
configured to send command signals via output channels to various
components of the vehicle 10. The controller 74 is also configured
to receive sensory feedback information or input signals via input
channels from various components of the vehicle 10. A single dotted
line between the controller 74 and another component of the vehicle
10 may be representative of both an input channel and an output
channel. The controller may include control logic that is
configured to generate various command signals in response to
various input signals. The command signals and input signals may be
transmitted and received as electrical signals. The controller 74
may communicate with various components of the vehicle 10 via input
and output channels including, but not limited to, the climate
control system 12, engine 14, electric machine 16, transmission 18,
engine disconnect clutch 32, traction battery 36, pump 42, fan 46,
thermostat 48, blower 56, valve 57, air-conditioning system 58
(including the compressor 62, expansion valve 68, and second fan
72). The cooling system 38 of the engine may include a coolant
temperature sensor 76 that communicates the current engine coolant
temperature to the controller 74. The cabin 54 may include a sensor
78 that communicates the current climate conditions (cabin air
temperature, humidity, etc.) to the controller 74.
[0014] The climate control system 12 may include a ram air inlet 80
the directs ram air across either the second heat exchanger 52 or
the evaporator 70 to either heat or cool, respectively, ram air
entering into the cabin 54, when the operator has activated the
climate control system 12, to heat or cool the cabin 54,
respectively. Ram air may directed across either the second heat
exchanger 52 or the evaporator 70 and into the cabin 54 when the
vehicle is moving and a pressure differential is produced between
the air surrounding the vehicle and the air in the vehicle cabin
54. The ram air inlet may include a door or a set of louvers 82
that only allows ram air to flow across either the second heat
exchanger 52 or the evaporator 70 and into the cabin 54 when the
door or louvers 82 are in an open position. Ram air may be
prevented from flowing across either the second heat exchanger 52
or the evaporator 70 and into the cabin 54 when the door or louvers
82 are in a closed position. The door or louvers 82 may remain in
the closed position when a recirculating mode is selected. The door
or louvers 82 may be connected to an actuator 84 that transitions
the door or louvers 82 between the opened and closed positions. The
actuator 84 may be in communication with the controller 74 via
input and output channels and may be configured to open and close
based on commands received from the controller 74.
[0015] The vehicle 10 may also include heated touch points 86 that
may be activated in order to increase user comfort levels. The
heated touch points 86 may include, but are not limited to, the
steering wheel, arm rest, center console, gear shifter, seat
bottom, and seat back. The heated touch points 86 may be activated
manually by the operator through a user interface 88 or
automatically in response to command signals from the controller 74
that are generated in response to a set of vehicle conditions. The
heated touch points 86 and the user interface 88 may both be in
communication with the controller 74 via input channels and output
channels.
[0016] The user interface 88 may include a touchscreen, a series of
buttons, a series of dials or knobs, etc. that are configured to
allow the vehicle operator to control various systems within the
vehicle 10. The user interface 88 may include user controls for the
climate control system 12 that allow the vehicle operator to select
between heating and cooling of the cabin 54. The user controls may
also include selecting the desired amount of heating and cooling
for the cabin 54. The user interface 88 may also include user
controls that communicate with the controller 74 to allow the
vehicle operator to select an economy mode that prioritizes fuel
economy over the selected comfort level (i.e., heating and cooling)
of the vehicle cabin 54. The economy mode may be selected to
operate automatically during key operating cycles of the vehicle
10. For example the economy mode may activate automatically during
a predicted commute that is expected to occur during certain days
of the week and/or during specific time periods of the day (e.g.,
the morning and evening commutes to and from work occurring Monday
through Friday). Alternatively, the economy mode may be configured
to activate during time periods that have been preselected by the
vehicle operator. The preselected time periods may correspond to
certain days of the week and/or during specific times of the day.
The economy mode may be configured to activate during subsequent
periods that correspond to the preselected time periods, even after
the vehicle has been turn off, unless the vehicle operator changes
or deletes the preselected time period. This may be referred to as
latching.
[0017] While illustrated as one controller, the controller 74 may
be part of a larger control system and may control or may be
controlled by various other controllers throughout the vehicle 10.
It should therefore be understood that the controller 74 and one or
more other controllers can collectively be referred to as a
"controller" that controls various actuators in response to signals
from various sensors to control functions such as starting/stopping
the engine 14, operating the electric machine 16 to provide wheel
torque or charge the traction battery 36, etc. The controller 74
may include a microprocessor or central processing unit (CPU) in
communication with various types of computer readable storage
devices or media. Computer readable storage devices or media may
include volatile and nonvolatile storage in read-only memory (ROM),
random-access memory (RAM), and keep-alive memory (KAM), for
example. KAM is a persistent or non-volatile memory that may be
used to store various operating variables while the CPU is powered
down. Computer- readable storage devices or media may be
implemented using any of a number of known memory devices such as
PROMs (programmable read-only memory), EPROMs (electrically PROM),
EEPROMs (electrically erasable PROM), flash memory, or any other
electric, magnetic, optical, or combination memory devices capable
of storing data, some of which represent executable instructions,
used by the controller 74 in controlling various components of the
vehicle 10.
[0018] Referring to FIG. 2, a flowchart representative of an engine
start-up method 100 is illustrated. The method 100 may be stored in
the form of control logic and/or algorithms within the memory of
the vehicle controller 74. The controller 74 may generate command
signals to implement and execute the method 100 based on the
control logic and/or algorithms. The command signals may be
generated based on the control logic and/or algorithms and in
response to input signals (including user inputs and various
vehicle conditions transmitted to the controller 74 via sensing
devices) received by the controller 74.
[0019] The method 100 is initiated at start block 102. Next, after
the method 100 has been initiated the method 100 moves on to block
104 where it is determined whether or not the engine 14 is off. If
the engine 14 is running and is not turned off, the method 100 ends
at block 105. If it is determined that the engine 14 is turned off,
the method 100 moves on to block 106 where is determined whether or
not the vehicle operator has selected an economy mode that
prioritizes fuel economy over the selected comfort level (i.e.,
heating and cooling) of the vehicle cabin 54.
[0020] If the vehicle operator has not selected the economy mode at
block 106, the method 100 moves on to block 107, where the blower
56 of the climate control system 12 will be commanded to operate at
a normal, standard, or desired rate (i.e., the normal operating
rate at which the blower delivers heated air into the vehicle cabin
54 to obtain the vehicle operator's selected desired comfort level)
if the vehicle operator selected to heat the vehicle cabin 54.
Next, the method 100 will move on to block 109 where the engine 14
will be commanded to start once the engine coolant temperature
becomes less than a first threshold. The first threshold may have
an approximate value of anywhere between 50.degree. C. and
70.degree. C. Also, there may be hysteresis value added to the
first threshold to prevent the engine 14 from turning on and off at
an undesired frequency. The hysteresis value may be added to the
first threshold while the engine coolant is either increasing or
decreasing. If the vehicle operator has not selected to heat the
vehicle cabin 54 after it has been determined that the vehicle
operator has not selected the economy mode at block 106, the blower
56 may be shut off and the threshold of the engine coolant
temperature at which the engine 14 is commanded to start may be
decreased to a lower value. The lower value of the threshold of the
engine coolant temperature at which the engine 14 is commanded to
start (when the vehicle operator has not selected to heat the
vehicle cabin 54 after it has been determined that the vehicle
operator has not selected the economy mode) may correspond to the
threshold engine coolant temperature at which the engine is
commanded to start that is discussed in block 116 below.
[0021] If the vehicle operator has selected the economy mode at
block 106, the method 100 moves on to block 108, where it is
determined whether or not the climate control system 12 is
requesting that heat be supplied to the cabin 54. If the climate
control system 12 is requesting that heat be supplied to the cabin
54, the method 100 moves on to block 110 where it is determined
whether or not the climate control system 12 is operating in or
requesting a defrost mode. If the climate control system 12 is
operating in a defrost mode, the method moves on to blocks 107 and
109, where the blower 56 is operated at the normal rate and the
engine is commanded to start once the engine coolant temperature
becomes less than the first threshold, respectively.
[0022] If it is determined that the climate control system 12 is
not in a defrost mode at block 110, the method 100 moves on to
block 112 where either the blower 56 of the climate control system
12 will be commanded to operate at a reduced rate (i.e., a rate
that is less than the normal operating rate at which the blower
delivers heated air into the vehicle cabin 54 to obtain the vehicle
operator's desired comfort level) or power to the blower 56 will be
cut and ram air will be heated via the second heat exchanger 52 and
delivered into the vehicle cabin 54. Choosing between commanding
the blower 56 of the climate control system 12 to operate at a
reduced rate and cutting power to the blower and delivering heated
ram air to the cabin 54 may be a selectable option, via the user
interface 88 or other switch, when the vehicle operator selects the
economy mode. Next, the method 100 will move on to block 114 where
the heated touch points 86 within the vehicle cabin 54 may be
activated. Block 114 may be an optional step depending on whether
or not the vehicle 10 includes heated touch points 86 or whether or
not the vehicle operator has requested that the heated touch points
86 activate when in the economy mode. After block 114, the method
will move on to block 116 where the engine 14 will be commanded to
start once the engine coolant temperature becomes less than a
second threshold that is less than the first threshold. The second
threshold may have an approximate value of anywhere between
30.degree. C. and 50.degree. C. Also, there may be hysteresis value
added to the second threshold to prevent the engine 14 from turning
on and off at an undesired frequency. The hysteresis value may be
added to the second threshold while the engine coolant is either
increasing or decreasing. Once the engine 14 is started, the blower
56 may be commanded to operate at the normal rate and touch points
may be deactivated. Alternatively, after the engine 14 is started,
the blower may remain operating at the reduced rate and the touch
points may remain activated.
[0023] Returning to block 108, if it is determined that the climate
control system 12 is not requesting that heat be supplied to the
cabin 54, the method 100 moves directly onto block 116, where the
engine 14 will be commanded to start once vehicle temperature
becomes less than the second threshold.
[0024] If at any time during the operation of the method 100 the
defrost mode is selected or requested, the blower 56 of the climate
control system 12 may be commanded to operate at the normal rate
according to block 107 (which may include eliminating delivering
ram air to the vehicle cabin 54) and the engine may be commanded to
start when the engine coolant temperature becomes less than the
first threshold according to block 109. Also, if at any time during
the operation of the method 100, the economy mode is terminated,
the blower 56 of the climate control system 12 may be commanded to
operate at the normal rate according to block 107 (which may
include eliminating delivering ram air the vehicle cabin 54) and
the engine may be commanded to start when the engine coolant
temperature becomes less than the first threshold according to
block 109.
[0025] There may also be an engine shut-down or engine stop coolant
temperature threshold that corresponds to a temperature that the
engine coolant must increase to before the engine is turned off
while the climate control system 12 is requesting that heat be
supplied to the cabin 54. The engine shut-down coolant temperature
threshold may be set to maintain an incremental value (e.g., a
hysteresis band which may remain constant) that is higher than the
engine coolant temperature values that trigger an engine-start up.
For example, when the economy mode is selected and the conditions
are such, according to the method 100 (with the exception of the
engine being off at block 104), that the engine coolant temperature
threshold that corresponds to triggering an engine start would
decrease from the first threshold (see block 109) to the second
threshold (see block 116), the engine shut-down coolant temperature
threshold may decrease by the same amount. Additionally, if the
economy mode is deselected or if the economy mode is selected and
the conditions are such, according to the method 100 (with the
exception of the engine being off at block 104), that the engine
coolant temperature threshold that corresponds to triggering an
engine start would increase from the second threshold (see block
109) to the first threshold (see block 116), the engine shut-down
coolant temperature threshold may increase by the same amount.
[0026] It should be understood that the flowchart illustrating the
engine start-up method 100 is meant for illustrative purposes. Some
of the steps may be rearranged while other steps may be omitted
entirely.
[0027] It should be understood that the hybrid vehicle
configuration described herein is merely exemplary and is not
intended to be limited. Other hybrid vehicle configurations should
be construed as disclosed herein. Other vehicle configurations may
include, but are not limited to, micro-hybrid vehicles, series
hybrid vehicles, parallel hybrid vehicles, series-parallel hybrid
vehicles, plug-in hybrid electric vehicles (PHEVs), or any other
hybrid vehicle configuration known to a person of ordinary skill in
the art.
[0028] The words used in the specification are words of description
rather than limitation, and it is understood that various changes
may be made without departing from the spirit and scope of the
disclosure. As previously described, the features of various
embodiments may be combined to form further embodiments that may
not be explicitly described or illustrated. While various
embodiments could have been described as providing advantages or
being preferred over other embodiments or prior art implementations
with respect to one or more desired characteristics, those of
ordinary skill in the art recognize that one or more features or
characteristics may be compromised to achieve desired overall
system attributes, which depend on the specific application and
implementation. As such, embodiments described as less desirable
than other embodiments or prior art implementations with respect to
one or more characteristics are not outside the scope of the
disclosure and may be desirable for particular applications.
* * * * *