U.S. patent application number 13/030321 was filed with the patent office on 2012-08-23 for vehicle auxiliary pump control.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to Ali K. Naqvi.
Application Number | 20120213643 13/030321 |
Document ID | / |
Family ID | 46652877 |
Filed Date | 2012-08-23 |
United States Patent
Application |
20120213643 |
Kind Code |
A1 |
Naqvi; Ali K. |
August 23, 2012 |
VEHICLE AUXILIARY PUMP CONTROL
Abstract
A vehicle includes a main pump and an auxiliary pump, each
configured to provide fluid to a hydraulic circuit. A motor is
configured to drive the auxiliary pump. A controller is configured
to determine a temperature of the motor, compare the temperature of
the motor to a first predetermined operating threshold, and disable
the auxiliary pump and enable the main pump if the temperature of
the motor is above the first predetermined operating threshold. A
method of controlling fluid flow in the vehicle includes
determining a temperature of the motor, comparing the temperature
to the first predetermined operating threshold, and disabling the
auxiliary pump and enabling the main pump if the temperature of the
motor is above the first predetermined operating threshold.
Inventors: |
Naqvi; Ali K.; (White Lake,
MI) |
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS
LLC
Detroit
MI
|
Family ID: |
46652877 |
Appl. No.: |
13/030321 |
Filed: |
February 18, 2011 |
Current U.S.
Class: |
417/1 |
Current CPC
Class: |
F16H 61/0031 20130101;
F04B 49/02 20130101 |
Class at
Publication: |
417/1 |
International
Class: |
F04B 49/02 20060101
F04B049/02 |
Claims
1. A vehicle comprising: a main pump configured to provide fluid to
a hydraulic circuit; an auxiliary pump configured to provide fluid
to the hydraulic circuit; a motor configured to drive the auxiliary
pump; and a controller configured to determine a temperature of the
motor, compare the temperature of the motor to a first
predetermined operating threshold, and disable the auxiliary pump
and enable the main pump if the temperature of the motor is above
the first predetermined operating threshold.
2. A vehicle as set forth in claim 1, further comprising a sensor
configured to measure the temperature of the motor.
3. A vehicle as set forth in claim 1, wherein the controller is
configured to estimate the temperature of the motor.
4. A vehicle as set forth in claim 1, wherein the controller is
configured to allow the auxiliary pump to be enabled if the
temperature of the motor falls below a second predetermined
operating threshold.
5. A vehicle as set forth in claim 4, wherein the first
predetermined operating threshold and the second predetermined
operating threshold each represents a different temperature.
6. A vehicle as set forth in claim 1, further comprising an engine
configured to provide a torque to drive the main pump.
7. A vehicle as set forth in claim 1, wherein the motor is
configured to provide a torque to drive the auxiliary pump.
8. A vehicle as set forth in claim 1, wherein the controller is
configured to disable the auxiliary pump by generating a control
signal that commands the motor to turn off.
9. A vehicle as set forth in claim 1, further comprising an engine
configured to drive the main pump, and wherein the controller is
configured to enable the main pump by generating a control signal
that commands the engine to turn on.
10. A method of controlling fluid flow in a vehicle, the method
comprising: determining a temperature of a motor driving the
auxiliary pump; comparing the temperature to a first predetermined
operating threshold; disabling the auxiliary pump if the
temperature of the motor is above the first predetermined operating
threshold; and enabling a main pump if the temperature of the motor
is above the first predetermined operating threshold.
11. A method as set forth in claim 10, wherein disabling the
auxiliary pump includes commanding the motor to turn off.
12. A method as set forth in claim 10, wherein enabling the pump
includes commanding an engine driving the main pump to turn on.
13. A method as set forth in claim 10, further comprising allowing
the motor to turn on to drive the auxiliary pump and allowing the
main pump to be disabled if the temperature is below a second
predetermined operating threshold.
14. A method as set forth in claim 10, wherein determining the
temperature of the motor includes measuring the temperature of the
motor with a sensor.
15. A method as set forth in claim 10, wherein determining the
temperature of the motor includes estimating a temperature of the
motor.
16. A method as set forth in claim 10, wherein disabling the
auxiliary pump includes setting a flag indicating that the
auxiliary pump is not available for use.
17. A method as set forth in claim 16, further comprising clearing
the flag if the temperature of the motor is below a second
predetermined operating threshold.
18. A vehicle comprising: a main pump configured to provide fluid
to a hydraulic circuit; an auxiliary pump configured to provide
fluid to the hydraulic circuit; a motor configured to drive the
auxiliary pump by providing a torque to the auxiliary pump; an
engine configured to drive the main pump by providing a torque to
the main pump; and a controller configured to determine a
temperature of the motor, compare the temperature of the motor to a
first predetermined operating threshold, and disable the auxiliary
pump and enable the main pump if the temperature of the motor is
above the first predetermined operating threshold, wherein the
controller is configured to disable the auxiliary pump by
commanding the motor to turn off and enable the main pump by
commanding the engine to turn on; and wherein the controller is
configured to allow the auxiliary pump to be enabled if the
temperature of the motor falls below a second predetermined
operating threshold.
19. A vehicle as set forth in claim 18, further comprising a sensor
configured to measure the temperature of the motor.
20. A vehicle as set forth in claim 18, wherein the controller is
configured to estimate the temperature of the motor.
Description
TECHNICAL FIELD
[0001] The invention relates to control of the use of an auxiliary
pump in a vehicle.
BACKGROUND
[0002] Passenger and commercial vehicles may use pumps driven by an
engine or motor to provide fluid to various hydraulic devices in
the vehicle. For example, the engine and/or motor may drive one or
more pumps by providing a torque to the pump. The pump, in turn,
provides pressurized fluid to hydraulic devices in the vehicle in
accordance with the torque provided by the engine and/or motor.
SUMMARY
[0003] An example vehicle includes a main pump, an auxiliary pump,
a motor, and a controller. The main pump and the auxiliary pump are
each configured to provide fluid to a hydraulic circuit. The motor
is configured to drive the auxiliary pump. The controller is
configured to determine a temperature of the motor and compare the
temperature of the motor to a first predetermined operating
threshold. The controller is further configured to disable the
auxiliary pump and enable the main pump if the temperature of the
motor is above the first predetermined operating threshold.
[0004] A method of controlling fluid flow in a vehicle includes
determining a temperature of a motor driving the auxiliary pump,
comparing the temperature to a first predetermined operating
threshold, and disabling the auxiliary pump if the temperature of
the motor is above the first predetermined operating threshold. The
method also includes enabling a main pump if the temperature of the
motor is above the first predetermined operating threshold.
[0005] The above features and the advantages and other features and
advantages of the present invention are readily apparent from the
following detailed description of the best modes for carrying out
the invention when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic diagram of an example vehicle
configured to control an auxiliary pump.
[0007] FIG. 2 is a flowchart of an example process that may be
implemented to control the auxiliary pump.
[0008] FIG. 3 is a flowchart of another example process that may be
implemented to control the auxiliary pump.
DETAILED DESCRIPTION
[0009] A vehicle is provided with a main pump, an auxiliary pump, a
motor, and a controller. The main pump and the auxiliary pump are
each configured to provide fluid to a hydraulic circuit. The motor
is configured to drive the auxiliary pump. The controller is
configured to determine a temperature of the motor and compare the
temperature of the motor to a first predetermined operating
threshold. The controller is further configured to disable the
auxiliary pump and enable the main pump if the temperature of the
motor is above the first predetermined operating threshold.
Accordingly, the controller may prevent the motor from failing if
the motor begins to overheat. The controller may be further
configured to allow the motor to turn back on after the motor has
had time to cool. This way, the controller may control the
operation of the auxiliary pump to prevent the motor from
overheating.
[0010] FIG. 1 illustrates a vehicle 100 able to determine whether a
motor is in danger of overheating, and if so, take appropriate
remedial action (e.g., disable an auxiliary pump). The vehicle 100
may take many different forms and include multiple and/or alternate
components and facilities. While an example vehicle 100 is shown in
the Figures, the components illustrated in the Figures are not
intended to be limiting. Indeed, additional or alternative
components and/or implementations may be used.
[0011] The vehicle 100 may include an engine 105, a motor 110, a
temperature sensor 115, a main pump 120, an auxiliary pump 125, a
hydraulic circuit 130, and a controller 135. The vehicle 100 may
include any automobile having two pumps driven by different
sources. For example, the vehicle 100 may be any passenger or
commercial automobile such as a hybrid electric vehicle including a
plug-in hybrid electric vehicle (PHEV) or an extended range
electric vehicle (EREV), a gas-powered vehicle, or the like.
[0012] The engine 105 may include any device configured to generate
torque from a fuel. For instance, the engine 105 may include an
internal combustion engine configured to output torque via a
crankshaft by burning a mixture of fuel and air. In one possible
implementation, the torque from the engine 105 may be output to a
transmission or gearbox (not shown). Further, the torque from the
engine 105 may be used to drive one or more other devices, such as
the main pump 120, which is described in detail below. Further, the
operation of the engine 105 may be controlled by an engine control
unit (not shown).
[0013] The motor 110 may include any device configured to convert
electrical energy into a torque. That is, the motor 110 may receive
electrical energy from a power source (not shown) such as a battery
and provide a torque via an output shaft using the electrical
energy. For example, the motor 110 may include a stator, a rotor,
and a commutator. The stator may include any device configured to
receive the electrical energy from the power source and generate a
magnetic field with the electrical energy. The rotor may include
any device configured to rotate relative to the stator when the
stator is provided with the electrical energy. That is, the rotor
may be configured to rotate in response to the magnetic field
produced by the stator. The commutator may include any device
configured to help the rotor maintain rotational motion, and thus,
help the motor 110 provide torque. The output shaft may be disposed
on the rotor such that the rotor and the output shaft rotate at
substantially the same speeds. In one possible approach, the motor
110 may further act as a generator and store electrical energy in
the power source if, for example, the motor 110 is provided with a
torque. For example, the engine 105 may provide the motor 110 with
a torque by using a belt (not shown) operably connected to the
crankshaft of the engine 105 and the output shaft of the motor 110.
The operation of the motor 110 may be controlled by a motor control
unit (not shown).
[0014] The temperature sensor 115 may include any device configured
to measure a temperature of the motor 110. The temperature sensor
115 may be operatively disposed on or near the motor 110 and may be
configured to generate a signal representative of the temperature
of the motor 110. For example, the temperature sensor 115 may be
configured to directly or indirectly measure the temperature of the
stator, the rotor, or electronics used to drive the motor 110. In
one possible implementation, the temperature of the motor 110 may
be estimated without the use of the temperature sensor 115 as
discussed in further detail below.
[0015] The main pump 120 may include any device configured to
provide fluid at a commanded pressure when provided with a torque.
For instance, the main pump 120 may be configured to receive the
torque generated by the engine 105 via the crankshaft and provide
fluid at a pressure based on the torque from the engine 105. Thus,
the main pump 120 may be configured to provide fluid at any time
the engine 105 is enabled.
[0016] The auxiliary pump 125 may include any device configured to
provide fluid at a commanded pressure when provided with a torque.
For instance, the auxiliary pump 125 may be configured to receive
the torque generated by the motor 110 via the output shaft and
provide fluid at a pressure based on the torque from the motor 110.
Thus, the main pump 120 may be configured to provide fluid at any
time the motor 110 is enabled.
[0017] The hydraulic circuit 130 may include any device configured
to provide fluid to one or more hydraulic components of the vehicle
100. The hydraulic circuit 130, therefore, may include a valve
body, one or more valves, one or more clutch assemblies, etc., or
any other hydraulic device configured to operate when provided with
pressurized fluid. The hydraulic circuit 130 may be operatively
connected to the main pump 120, the auxiliary pump 125, or both.
This way, the main pump 120, the auxiliary pump 125, or both, may
provide fluid to the hydraulic devices of the hydraulic circuit
130. Of course, the vehicle 100 may have any number of hydraulic
circuits 130 operatively connected to one or both of the main pump
120 and the auxiliary pump 125.
[0018] The controller 135 may include any device configured to
control various aspects of the vehicle 100. For example, in some
circumstances, the controller 135 may be configured to command the
engine 105, motor 110, or both to turn on or off. For example, the
controller 135 may be configured to command the motor 110 on and
the engine 105 off when the power source can supply a sufficient
amount of electrical energy for the motor 110 or another motor (not
shown) to propel the vehicle 100. If, however, the electrical
energy stored in the power source drops below a certain level, the
controller 135 may be configured to command the engine 105 to turn
on to provide torque to the motor 110 to cause the motor 110 to
generate electricity that may be stored in the power source.
Alternatively, the controller 135 may command the engine 105 to
turn on to provide torque to a transmission (not shown) to propel
the vehicle 100 directly. Accordingly, the controller 135 may
control different operating modes of the vehicle 100 based on
whether the engine 105, the motor 110, or both are commanded
on.
[0019] The controller 135 may be further configured to command the
motor 110 and/or engine 105 on or off for reasons other than to
propel the vehicle 100. For example, the controller 135 may command
the motor 110 on or off to control the operation of the auxiliary
pump 125 and the controller 135 may command the engine 105 on or
off to control the operation of the main pump 120. The controller
135 may do so for various reasons, such as to reduce motor failure
if the motor 110 driving the auxiliary pump 125 becomes too
hot.
[0020] In one possible approach, the controller 135 may be
configured to determine a temperature of the motor 110 and compare
the temperature of the motor 110 to a first predetermined operating
threshold, which may represent the maximum temperature at which the
motor 110 may operate. The controller 135 may be configured to
receive the temperature measured by the temperature sensor 115.
Alternatively, the controller 135 may estimate the temperature of
the motor 110 based on various factors such as the amount of
current provided to the motor 110 from the power source, the speed
of the motor 110, the amount of torque generated by the motor 110,
etc.
[0021] If the temperature of the motor 110 is above the first
predetermined operating threshold, the controller 135 may be
configured to disable the motor 110 to disable the auxiliary pump
125 and enable the main pump 120 to provide fluid to the hydraulic
circuit 130. To disable the auxiliary pump 125, the controller 135
may be configured to transmit a control signal to the motor 110
that commands the motor 110 to turn off. To enable the main pump
120, the controller 135 may be configured to transmit a control
signal that commands the engine 105 to turn on. Additionally, the
controller 135 may set a flag indicating that the motor 110 may not
be commanded on despite other requests for torque from the motor
110. When the flag is set, the controller 135 may cause the engine
105 to generate the torque requested by the motor 110, including
the torque to drive the main pump 120 to provide fluid to the
hydraulic circuit 130.
[0022] If the temperature falls below a second predetermined
operating threshold, the controller 135 may be configured to allow
the auxiliary pump 125 to be enabled. For example, the controller
135 may be configured to clear the flag and allow the motor 110 to
provide torque to the auxiliary pump 125. Clearing the flag may
indicate that the auxiliary pump 125 is available for use. That is,
once the flag is clear, the controller 135 may be configured to
allow the main pump 120 to be disabled (e.g., when the engine 105
is commanded off). However, the controller 135 need not immediately
disable the main pump 120 and enable the motor 110 when the flag is
clear. For example, the vehicle 100 may be operating in an "engine
only" mode (e.g., only the engine 105 is commanded on to propel the
vehicle) when the flag is cleared. Clearing the flag may allow the
controller 135 to command the motor 110 to turn on when the vehicle
100 is no longer operating in the "engine only" mode. The first and
second predetermined operating thresholds may represent the same or
different temperatures. If different temperatures, the controller
135 may give the motor 110 additional time to cool even after the
temperature of the motor 110 has fallen below the first
predetermined operating threshold.
[0023] In general, computing systems and/or devices, such as the
controller 135, the engine control unit, the motor control unit,
etc., may employ any of a number of computer operating systems and
generally include computer-executable instructions, where the
instructions may be executable by one or more computing devices
such as those listed above. Computer-executable instructions may be
compiled or interpreted from computer programs created using a
variety of well known programming languages and/or technologies,
including, without limitation, and either alone or in combination,
Java.TM., C, C++, Visual Basic, Java Script, Perl, etc. In general,
a processor (e.g., a microprocessor) receives instructions, e.g.,
from a memory, a computer-readable medium, etc., and executes these
instructions, thereby performing one or more processes, including
one or more of the processes described herein. Such instructions
and other data may be stored and transmitted using a variety of
known computer-readable media.
[0024] A computer-readable medium (also referred to as a
processor-readable medium) includes any non-transitory (e.g.,
tangible) medium that participates in providing data (e.g.,
instructions) that may be read by a computer (e.g., by a processor
of a computer). Such a medium may take many forms, including, but
not limited to, non-volatile media and volatile media. Non-volatile
media may include, for example, optical or magnetic disks and other
persistent memory. Volatile media may include, for example, dynamic
random access memory (DRAM), which typically constitutes a main
memory. Such instructions may be transmitted by one or more
transmission media, including coaxial cables, copper wire and fiber
optics, including the wires that comprise a system bus coupled to a
processor of a computer. Common forms of computer-readable media
include, for example, a floppy disk, a flexible disk, hard disk,
magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other
optical medium, punch cards, paper tape, any other physical medium
with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM,
any other memory chip or cartridge, or any other medium from which
a computer can read.
[0025] FIG. 2 illustrates an example process 200 that may be
implemented by the controller 135 to control the use of the
auxiliary pump 125 to, for example, protect the motor 110 from
overheating.
[0026] At block 205, the controller 135 may determine the
temperature of the motor 110. For example, the controller 135 may
receive the signal generated by the temperature sensor 115 or
estimate the temperature based on factors such as the amount of
current provided to the motor 110 from the power source, the speed
of the motor 110, the amount of torque generated by the motor 110,
etc.
[0027] At decision block 210, the controller 135 may compare the
temperature determined at block 205 to the first predetermined
operating threshold. The first predetermined operating threshold
may represent the maximum temperature at which the controller 135
will allow the motor 110 to operate before disabling the motor 110.
If the temperature is below the first predetermined operating
threshold, the process 200 may continue at block 205. If the
temperature is above the predetermined operating threshold, the
process 200 may continue at block 215.
[0028] At block 215, the controller 135 may disable the auxiliary
pump 125. For example, the controller 135 may command the motor 110
to turn off. As discussed above, the torque provided by the motor
110 drives the auxiliary pump 125. Thus, commanding the motor 110
to turn off will disable the auxiliary pump 125 and the process 200
may continue at block 220.
[0029] At block 220, the controller 135 may enable the main pump
120 by, for instance, commanding the engine 105 to turn on. As
discussed above, the torque provided by the engine 105 drives the
main pump 120. Accordingly, commanding the engine 105 to turn on
causes the main pump 120 to provide fluid to the hydraulic circuit
130. As such, the hydraulic circuit 130 may still receive fluid if
the temperature of the motor 110 is above the first predetermined
operating threshold.
[0030] FIG. 3 illustrates another example process 300 that may be
implemented by the controller 135 to control the use of the
auxiliary pump 125 to, for example, protect the motor 110 from
overheating.
[0031] At block 305, the controller 135 may determine the
temperature of the motor 110. For example, the controller 135 may
receive the signal generated by the temperature sensor 115 or
estimate the temperature based on factors such as the amount of
current provided to the motor 110 from the power source, the speed
of the motor 110, the amount of torque generated by the motor 110,
etc.
[0032] At decision block 310, the controller 135 may compare the
temperature determined at block 305 to the first predetermined
operating threshold. As previously discussed, the first
predetermined operating threshold may represent the maximum
temperature at which the controller 135 will allow the motor 110 to
operate before disabling the motor 110. If the temperature is below
the first predetermined operating threshold, the process 300 may
continue at block 305. If the temperature is above the
predetermined operating threshold, the process 300 may continue at
block 315.
[0033] At block 315, the controller 135 may set a flag indicating
that the motor 110 may not be commanded on despite requests for
torque from the motor 110. Therefore, the controller 135 and other
electronic devices such as the motor control unit may be unable to
command the motor 110 to turn on when the flag is set. Further,
setting the flag may further indicate that the auxiliary pump 125
is not available for use.
[0034] At block 320, the controller 135 may command the motor 110
to turn off. As discussed above, commanding the motor 110 to turn
off may cause the auxiliary pump 125 to cease providing fluid to
the hydraulic circuit 130. Additionally, turning the motor 110 off
will allow the motor 110 to cool.
[0035] At block 325, the controller 135 may command the engine 105
to turn on to, for example, drive the main pump 120 and provide
fluid to the hydraulic circuit 130. As discussed above, the flag
set at block 315 may indicate that the auxiliary pump 125 is not
available for use. The controller 135 may command the engine 105 on
and thus enable the main pump 120 to provide fluid to the hydraulic
circuit 130 so that the hydraulic circuit 130 may still operate
despite the temperature of the motor 110.
[0036] At block 330, the controller 135 may determine the
temperature. For instance, the controller 135 may estimate the
temperature of the motor 110 or receive the measured temperature
from the temperature sensor 115.
[0037] At decision block 335, the controller 135 may compare the
temperature measured at block 330 to the second predetermined
operating threshold. The second predetermined operating threshold
may represent a temperature at which the motor 110 may be enabled
without significant risk of overheating. If the temperature
measured at block 330 is above the second predetermined operating
threshold, the process 300 may continue at block 330. If, however,
the temperature of the motor 110 measured at block 330 is below the
second predetermined threshold, the process 300 may continue at
block 340.
[0038] At block 340, the controller 135 may clear the flag to allow
the motor 110 to turn on to drive the auxiliary pump 125. Clearing
the flag may indicate that the auxiliary pump 125 is available for
use. That is, once the flag is clear, the controller 135 may allow
the main pump 120 to be disabled (e.g., when the engine 105 is
commanded off). However, the controller 135 need not immediately
disable the main pump 120 and enable the motor 110 when the flag is
clear. For example, the vehicle 100 may be operating in an "engine
only" mode (e.g., only the engine 105 is commanded on to provide
torque to the wheels) when the flag is cleared. Clearing the flag
may allow the motor 110 to be commanded on when the vehicle 100 is
no longer operating in the "engine only" mode.
[0039] While the best modes for carrying out the invention have
been described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention within the scope of the
appended claims.
* * * * *