Title of Invention	AN ENGINE CONTROL SYSTEM AND A METHOD FOR CONTROLLING AN INTERNAL COMBUSTION ENGINE TO TRANSITION BETWEEN AN ACTIVATED AND DEACTIVATED MODE
Abstract	An engine control system for controlling the engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active is provided. The system includes: a noise vibration and harshness (NVH) limit module that determines a noise, vibration, and harshness (NVH) torque limit based on the engine speed and the vehicle speed; and a mode transition module that enables the engine to transition between the deactivated mode and the activated mode while limiting noise, vibration, and harshness based on the NVH torque limit and a requested torque.

Title of Invention

AN ENGINE CONTROL SYSTEM AND A METHOD FOR CONTROLLING AN INTERNAL COMBUSTION ENGINE TO TRANSITION BETWEEN AN ACTIVATED AND DEACTIVATED MODE

Abstract

An engine control system for controlling the engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active is provided. The system includes: a noise vibration and harshness (NVH) limit module that determines a noise, vibration, and harshness (NVH) torque limit based on the engine speed and the vehicle speed; and a mode transition module that enables the engine to transition between the deactivated mode and the activated mode while limiting noise, vibration, and harshness based on the NVH torque limit and a requested torque.

Full Text	GP 307894-PTE-CD 1 CYLINDER DEACTIVATION TORQUE LIMIT FOR NOISE, VIBRATION, AND HARSHNESS FIELD [0001] The present disclosure relates to methods and systems for displacement on demand internal combustion engines. BACKGROUND [0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. [0003] Some internal combustion engines include engine control systems that deactivate one or more cylinders during operation. The deactivation typically occurs under low load situations. For example, an eight cylinder engine can be operated using four cylinders to improve fuel economy by reducing pumping losses. This process is generally referred to as displacement on demand or DOD. Operation using all of the engine cylinders is referred to as an activated mode. A deactivated mode refers to operation using less than all of the cylinders of the engine (one or more cylinders not active). [0004] Conventional methods of controlling the engine to transition between the activated mode and the deactivated mode are based on engine vacuum. Some methods include an engine vacuum hysteresis pair to prevent toggling between the activated and deactivated modes. These methods neglect engine torque and have a negative impact on fuel economy during low engine torque conditions. Likewise, the methods tend to have a negative impact on noise, vibration, and harshness during high engine torque conditions. GP 307894-PTE-CD 2 SUMMARY [0005] Accordingly, an engine control system for controlling the engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active is provided. The system includes: a noise vibration and harshness (NVH) limit module that determines a noise, vibration, and harshness (NVH) torque limit based on the engine speed and the vehicle speed; and a mode transition module that enables the engine to transition between the deactivated mode and the activated mode while limiting noise, vibration, and harshness based on the NVH torque limit and a requested torque. [0006] In other features, a method of controlling an internal combustion engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active is provided. The method includes: determining a noise, vibration, and harshness (NVH) torque limit based on engine speed and vehicle speed; and controlling the engine to transition from the deactivated mode to the activated mode while limiting NVH if a requested torque is greater than the NVH torque limit. [0007] In still other features, a method of controlling an internal combustion engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active is provided. The method includes: determining a noise, vibration, and harshness (NVH) torque limit based on engine speed and vehicle speed; and controlling the engine to transition from the activated mode to the deactivated mode while limiting NVH if a requested torque is less than the NVH torque limit minus a hysteresis. [0008] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. GP 307894-PTE-CD 3 DRAWINGS [0009] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. [0010] Figure 1 is a functional block diagram of a vehicle including a displacement on demand internal combustion engine. [0011] Figure 2 is a dataflow diagram illustrating a cylinder deactivation system. [0012] Figure 3 is a flowchart illustrating a method of controlling cylinder deactivation based on a torque limit for noise, vibration, and harshness (NVH). [0013] Figure 4 is a graph illustrating noise data during cylinder deactivation events with NVH torque limit control and without the NVH torque limit control. DETAILED DESCRIPTION [0014] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. As used herein, activated refers to operation using all of the engine cylinders. Deactivated refers to operation using less than all of the cylinders of the engine (one or more cylinders not active). As used herein, the term module refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. [0015] Referring now to Figure 1, a vehicle 10 includes an engine 12 that drives a transmission 14. The transmission 14 is either an automatic or a manual transmission that is driven by the engine 12 through a corresponding torque converter or clutch 16. Air flows into the engine 12 through a throttle 13. The engine 12 includes N cylinders 18. One or more of GP 307894-PTE-CD 4 the cylinders 18 are selectively deactivated during engine operation. Although Figure 1 depicts eight cylinders (N = 8), it is appreciated that the engine 12 may include additional or fewer cylinders 18. For example, engines having 4, 5,6,8,10,12 and 16 cylinders are contemplated. Air flows into the engine 12 through an intake manifold 20 and is combusted with fuel in the cylinders 18. [0016] Intake valves 24 of the engine selectively open and close to enable the air to enter the cylinders 18 through inlet ports. A position of the intake valves is regulated by an intake camshaft 26. Fuel injectors (not shown) simultaneously injects fuel into the cylinders 18. The fuel injectors are controlled to provide a desired air-to-fuel (A/F) ratio within the cylinder 18. Pistons (not shown) compress the A/F mixture within the cylinders 18. The compression of the hot air ignites the fuel in the cylinders 18, which drives the pistons. The pistons, in turn, drive a crankshaft (not shown) to produce drive torque. Combustion exhaust within the cylinders 18 is forced out exhaust ports when exhaust valves 28 are in an open position. A position of the exhaust valves is regulated by an exhaust camshaft 30. Although single intake and exhaust valves 24 and 28 are illustrated per cylinder 18, it can be appreciated that the engine 12 can include multiple intake and exhaust valves 24 and 28 per cylinder 18. [0017] A control module 32 communicates with the engine 12 and various inputs and sensors as discussed herein. An engine speed sensor 34 generates a signal based on engine speed. An intake manifold absolute pressure (MAP) sensor 36 generates a signal based on a pressure of the intake manifold 20. A mass airflow (MAF) sensor 38 generates a signal based on the mass of air flowing into the engine 12. A vehicle speed sensor (not shown) is located along the driveline (not shown) of the vehicle and generates a vehicle speed signal. [0018] A vehicle operator manipulates an accelerator pedal 40 to regulate the throttle 13. More particularly, a pedal position sensor 42 generates a pedal position signal that is communicated to the control module 32. The control module 32 calculates a driver requested torque from the GP 307894-PTE-CD 5 pedal position signal. The control module 32 determines an engine torque from the various airflow, RPM, load, and temperature sensors signals according to conventional methods. The control module 32 generates a throttle control signal based on the requested torque and the engine torque. A throttle actuator (not shown) adjusts the throttle 13 based on the throttle control signal to regulate airflow into the engine 12 [0019] When light engine load occurs, the control module 32 transitions the engine 12 to the deactivated mode. In an exemplary embodiment, N/2 cylinders 18 are deactivated. Fuel, air, and spark are cut off to the deactivated cylinders. The inlet and exhaust ports of the deactivated cylinders 18 are closed to reduce pumping losses. A lost motion device may act to decouple the intake and exhaust valves 24 and 28 from their respective camshafts 26 and 30 to disable operation. [0020] Referring now to Figure 2, the present disclosure provides a control method and system that governs the transitions between the activated mode and the deactivated mode based on a noise, vibration, and harshness (NVH) torque limit. The NVH torque limit is determined as the maximum amount of torque that can be produced in the deactivated mode without generating excessive noise, vibration, and harshness.(NVH). A dataflow diagram illustrates various embodiments of the cylinder deactivation system that may be embedded within the control module 32. Various embodiments of cylinder deactivation systems according to the present disclosure may include any number of sub-modules embedded within the control module 32. The sub-modules shown may be combined and/or further partitioned to similarly govern the transitions between the activated mode and the deactivated mode. [0021] In various embodiments, the control module 32 of Figure 2 includes an NVH limit module 50 and a mode transition module 52. The NVH limit module 50 receives as input engine speed 54 and vehicle speed 56. As can be appreciated, the inputs to the system may be sensed from the vehicle 10, received from other control modules (not shown) within the vehicle 10, or determined from other sub-modules within the control module 32. The NVH GP 307894-PTE-CD 6 limit module 50 determines a NVH torque limit 58 based on the engine speed 54 and vehicle speed 56. The mode transition module 52 receives as input the NVH torque limit 58 and a torque request 60. The mode transition module 52 selects a current mode 62 to be either the activated mode or the deactivated mode based on a comparison of the NVH torque limit 58 and the torque request 60. [0022] Referring now to Figure 3, a flowchart illustrates a method of controlling cylinder deactivation based on torque limits for NVH according to the present disclosure. The method shown may be continually run while the vehicle ignition is on. In an exemplary embodiment, the method is run every one second. In Figure 3, a driver's requested torque is determined from the throttle position at 100. A NVH torque value for NVH is determined based on engine speed and vehicle speed at 102. In various embodiments, the maximum torque limit may be interpolated from a two dimensional table with engine speed and vehicle speed as the indices. If the engine is in the deactivated mode at 104, control evaluates the driver requested torque at 106. If the driver requested torque is greater than or equal to the NVH torque limit for NVH at 106, control transitions the engine to the activated mode at 110. Otherwise, if the engine is not in the activated mode at 104, control evaluates the driver's requested torque at 108. If the driver's requested torque is less than the NVH torque limit for NVH minus a hysteresis at 108, control evaluates other deactivated mode enable conditions at 112. If other engine deactivation mode conditions, including but not limited to, adequate oil pressure, engine speed, and transmission gear are met at 112, control transitions the engine to the deactivated mode at 114. [0023] Referring now to Figure 4, a graph illustrates noise data during cylinder deactivation operation with the NVH torque limit control method activated and without the NVH torque limit control activated. Sound pressure levels in decibels (dB) are shown along the y-axis at 200. Engine speed in RPM is shown along the x-axis at 210. Sound pressure level data obtained without the NVH torque limit method activated is shown at 220. GP 307894-PTE-CD 7 Sound pressure level data obtained with the NVE torque limit method activated is shown at 230. The target NVH level is shown at 240. It can easily be seen that the NVH limit is noticeable improvement over the unlimited operation with respect to the target NVH. [0024] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, while this disclosure has been described in connection with particular examples thereof, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and the following claims. GP 307894-PTE-CD 8 CLAIMS What is claimed is: 1. An engine control system for controlling the engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active, comprising: a noise vibration and harshness (NVH) limit module that determines a noise, vibration, and harshness (NVH) torque limit based on the engine speed and the vehicle speed; and a mode transition module that enables the engine to transition between the deactivated mode and the activated mode while limiting noise, vibration, and harshness based on the NVH torque limit and a requested torque. 2. The system of claim 1 wherein the mode transition module enables the engine to transition from the activated mode to the deactivated mode based on the NVH torque limit, a hysteresis, and the requested torque. 3. The system of claim 1 wherein the mode transition module commands the transition from the deactivated mode to the activated mode if the requested torque is greater than the NVH torque limit. 4. The system of claim 1 wherein the mode transition module commands the transition from the deactivated mode to the activated mode if the requested torque is equal to the NVH torque limit. 5. The system of claim 2 wherein the mode transition module enables the transition from the activated mode to the deactivated mode if the requested torque is less than the NVH torque limit minus the hysteresis. GP 307894-PTE-CD 9 6. The system of claim 4 wherein the mode transition module enables the transition from the activated mode to the deactivated mode if engine deactivation enable conditions are met. 7. The system of claim 1 wherein the mode transition module determines the requested torque based on an accelerator pedal position. 8. The method of claim 1 wherein the NVH limit module determines the NVH torque limit based on an interpolation of values stored in a two dimensional table defined by indices of engine speed and vehicle speed. 9. A method of controlling an internal combustion engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active, comprising: determining a noise, vibration, and harshness (NVH) torque limit based on engine speed and vehicle speed; and controlling the engine to transition from the deactivated mode to the activated mode while limiting NVH if a requested torque is greater than the NVH torque limit. 10. The method of claim 9 further comprising controlling the engine to transition from the deactivated mode to the activated mode if the requested torque is equal to the NVH torque limit. 11. The method of claim 9 further comprising controlling the engine to transition from the activated mode to the deactivated mode if the requested torque is less than the NVH torque limit minus a hysteresis. 12. The method of claim 11 further comprising controlling the engine to transition from the activated mode to the deactivated mode if engine deactivation enable conditions are met. GP 307894-PTE-CD 10 13. The method of claim 9 further comprising determining the requested torque from an accelerator pedal position. 14. The method of claim 9 wherein the determining comprises determining the NVH torque limit based on interpolating values from a two dimensional table defined by indices of engine speed and vehicle speed. 15. A method of controlling an internal combustion engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active, comprising: determining a noise, vibration, and harshness (NVH) torque limit based on engine speed and vehicle speed; and controlling the engine to transition from the activated mode to the deactivated mode while limiting NVH if a requested torque is less than the NVH torque limit minus a hysteresis. 16. The method of claim 15 wherein the controlling comprises controlling the engine to transition from the activated mode to the deactivated mode if the requested torque is less than the NVH torque limit minus a hysteresis and if engine deactivation enable conditions are met. 17. The method of claim 15 further comprising determining the requested torque from an accelerator pedal position. 18. The method of claim 15 wherein the determining comprises determining the NVH torque limit based on interpolating values from a two dimensional table defined by indices of engine speed and vehicle speed. An engine control system for controlling the engine to transition between an activated mode where all cylinders are active and a deactivated mode where less than all cylinders are active is provided. The system includes: a noise vibration and harshness (NVH) limit module that determines a noise, vibration, and harshness (NVH) torque limit based on the engine speed and the vehicle speed; and a mode transition module that enables the engine to transition between the deactivated mode and the activated mode while limiting noise, vibration, and harshness based on the NVH torque limit and a requested torque.

Full Text

GP 307894-PTE-CD
1
CYLINDER DEACTIVATION TORQUE LIMIT FOR NOISE,
VIBRATION, AND HARSHNESS
FIELD
[0001] The present disclosure relates to methods and systems for
displacement on demand internal combustion engines.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not constitute prior art.
[0003] Some internal combustion engines include engine control
systems that deactivate one or more cylinders during operation. The
deactivation typically occurs under low load situations. For example, an eight
cylinder engine can be operated using four cylinders to improve fuel economy
by reducing pumping losses. This process is generally referred to as
displacement on demand or DOD. Operation using all of the engine cylinders
is referred to as an activated mode. A deactivated mode refers to operation
using less than all of the cylinders of the engine (one or more cylinders not
active).
[0004] Conventional methods of controlling the engine to transition
between the activated mode and the deactivated mode are based on engine
vacuum. Some methods include an engine vacuum hysteresis pair to prevent
toggling between the activated and deactivated modes. These methods
neglect engine torque and have a negative impact on fuel economy during low
engine torque conditions. Likewise, the methods tend to have a negative
impact on noise, vibration, and harshness during high engine torque
conditions.

GP 307894-PTE-CD
2
SUMMARY
[0005] Accordingly, an engine control system for controlling the
engine to transition between an activated mode where all cylinders are active
and a deactivated mode where less than all cylinders are active is provided.
The system includes: a noise vibration and harshness (NVH) limit module that
determines a noise, vibration, and harshness (NVH) torque limit based on the
engine speed and the vehicle speed; and a mode transition module that
enables the engine to transition between the deactivated mode and the
activated mode while limiting noise, vibration, and harshness based on the
NVH torque limit and a requested torque.
[0006] In other features, a method of controlling an internal
combustion engine to transition between an activated mode where all
cylinders are active and a deactivated mode where less than all cylinders are
active is provided. The method includes: determining a noise, vibration, and
harshness (NVH) torque limit based on engine speed and vehicle speed; and
controlling the engine to transition from the deactivated mode to the activated
mode while limiting NVH if a requested torque is greater than the NVH torque
limit.
[0007] In still other features, a method of controlling an internal
combustion engine to transition between an activated mode where all
cylinders are active and a deactivated mode where less than all cylinders are
active is provided. The method includes: determining a noise, vibration, and
harshness (NVH) torque limit based on engine speed and vehicle speed; and
controlling the engine to transition from the activated mode to the deactivated
mode while limiting NVH if a requested torque is less than the NVH torque
limit minus a hysteresis.
[0008] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the description and
specific examples are intended for purposes of illustration only and are not
intended to limit the scope of the present disclosure.

GP 307894-PTE-CD
3
DRAWINGS
[0009] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present disclosure in any
way.
[0010] Figure 1 is a functional block diagram of a vehicle including a
displacement on demand internal combustion engine.
[0011] Figure 2 is a dataflow diagram illustrating a cylinder
deactivation system.
[0012] Figure 3 is a flowchart illustrating a method of controlling
cylinder deactivation based on a torque limit for noise, vibration, and
harshness (NVH).
[0013] Figure 4 is a graph illustrating noise data during cylinder
deactivation events with NVH torque limit control and without the NVH torque
limit control.
DETAILED DESCRIPTION
[0014] The following description is merely exemplary in nature and
is not intended to limit the present disclosure, application, or uses. It should
be understood that throughout the drawings, corresponding reference
numerals indicate like or corresponding parts and features. As used herein,
activated refers to operation using all of the engine cylinders. Deactivated
refers to operation using less than all of the cylinders of the engine (one or
more cylinders not active). As used herein, the term module refers to an
application specific integrated circuit (ASIC), an electronic circuit, a processor
(shared, dedicated, or group) and memory that executes one or more
software or firmware programs, a combinational logic circuit, and/or other
suitable components that provide the described functionality.
[0015] Referring now to Figure 1, a vehicle 10 includes an engine
12 that drives a transmission 14. The transmission 14 is either an automatic
or a manual transmission that is driven by the engine 12 through a
corresponding torque converter or clutch 16. Air flows into the engine 12
through a throttle 13. The engine 12 includes N cylinders 18. One or more of

GP 307894-PTE-CD
4
the cylinders 18 are selectively deactivated during engine operation. Although
Figure 1 depicts eight cylinders (N = 8), it is appreciated that the engine 12
may include additional or fewer cylinders 18. For example, engines having 4,
5,6,8,10,12 and 16 cylinders are contemplated. Air flows into the engine 12
through an intake manifold 20 and is combusted with fuel in the cylinders 18.
[0016] Intake valves 24 of the engine selectively open and close to
enable the air to enter the cylinders 18 through inlet ports. A position of the
intake valves is regulated by an intake camshaft 26. Fuel injectors (not
shown) simultaneously injects fuel into the cylinders 18. The fuel injectors are
controlled to provide a desired air-to-fuel (A/F) ratio within the cylinder 18.
Pistons (not shown) compress the A/F mixture within the cylinders 18. The
compression of the hot air ignites the fuel in the cylinders 18, which drives the
pistons. The pistons, in turn, drive a crankshaft (not shown) to produce drive
torque. Combustion exhaust within the cylinders 18 is forced out exhaust
ports when exhaust valves 28 are in an open position. A position of the
exhaust valves is regulated by an exhaust camshaft 30. Although single
intake and exhaust valves 24 and 28 are illustrated per cylinder 18, it can be
appreciated that the engine 12 can include multiple intake and exhaust valves
24 and 28 per cylinder 18.
[0017] A control module 32 communicates with the engine 12 and
various inputs and sensors as discussed herein. An engine speed sensor 34
generates a signal based on engine speed. An intake manifold absolute
pressure (MAP) sensor 36 generates a signal based on a pressure of the
intake manifold 20. A mass airflow (MAF) sensor 38 generates a signal
based on the mass of air flowing into the engine 12. A vehicle speed sensor
(not shown) is located along the driveline (not shown) of the vehicle and
generates a vehicle speed signal.
[0018] A vehicle operator manipulates an accelerator pedal 40 to
regulate the throttle 13. More particularly, a pedal position sensor 42
generates a pedal position signal that is communicated to the control module
32. The control module 32 calculates a driver requested torque from the

GP 307894-PTE-CD
5
pedal position signal. The control module 32 determines an engine torque
from the various airflow, RPM, load, and temperature sensors signals
according to conventional methods. The control module 32 generates a
throttle control signal based on the requested torque and the engine torque.
A throttle actuator (not shown) adjusts the throttle 13 based on the throttle
control signal to regulate airflow into the engine 12
[0019] When light engine load occurs, the control module 32
transitions the engine 12 to the deactivated mode. In an exemplary
embodiment, N/2 cylinders 18 are deactivated. Fuel, air, and spark are cut off
to the deactivated cylinders. The inlet and exhaust ports of the deactivated
cylinders 18 are closed to reduce pumping losses. A lost motion device may
act to decouple the intake and exhaust valves 24 and 28 from their respective
camshafts 26 and 30 to disable operation.
[0020] Referring now to Figure 2, the present disclosure provides a
control method and system that governs the transitions between the activated
mode and the deactivated mode based on a noise, vibration, and harshness
(NVH) torque limit. The NVH torque limit is determined as the maximum
amount of torque that can be produced in the deactivated mode without
generating excessive noise, vibration, and harshness.(NVH). A dataflow
diagram illustrates various embodiments of the cylinder deactivation system
that may be embedded within the control module 32. Various embodiments of
cylinder deactivation systems according to the present disclosure may include
any number of sub-modules embedded within the control module 32. The
sub-modules shown may be combined and/or further partitioned to similarly
govern the transitions between the activated mode and the deactivated mode.
[0021] In various embodiments, the control module 32 of Figure 2
includes an NVH limit module 50 and a mode transition module 52. The NVH
limit module 50 receives as input engine speed 54 and vehicle speed 56. As
can be appreciated, the inputs to the system may be sensed from the vehicle
10, received from other control modules (not shown) within the vehicle 10, or
determined from other sub-modules within the control module 32. The NVH

GP 307894-PTE-CD
6
limit module 50 determines a NVH torque limit 58 based on the engine speed
54 and vehicle speed 56. The mode transition module 52 receives as input
the NVH torque limit 58 and a torque request 60. The mode transition module
52 selects a current mode 62 to be either the activated mode or the
deactivated mode based on a comparison of the NVH torque limit 58 and the
torque request 60.
[0022] Referring now to Figure 3, a flowchart illustrates a method of
controlling cylinder deactivation based on torque limits for NVH according to
the present disclosure. The method shown may be continually run while the
vehicle ignition is on. In an exemplary embodiment, the method is run every
one second. In Figure 3, a driver's requested torque is determined from the
throttle position at 100. A NVH torque value for NVH is determined based on
engine speed and vehicle speed at 102. In various embodiments, the
maximum torque limit may be interpolated from a two dimensional table with
engine speed and vehicle speed as the indices. If the engine is in the
deactivated mode at 104, control evaluates the driver requested torque at
106. If the driver requested torque is greater than or equal to the NVH torque
limit for NVH at 106, control transitions the engine to the activated mode at
110. Otherwise, if the engine is not in the activated mode at 104, control
evaluates the driver's requested torque at 108. If the driver's requested
torque is less than the NVH torque limit for NVH minus a hysteresis at 108,
control evaluates other deactivated mode enable conditions at 112. If other
engine deactivation mode conditions, including but not limited to, adequate oil
pressure, engine speed, and transmission gear are met at 112, control
transitions the engine to the deactivated mode at 114.
[0023] Referring now to Figure 4, a graph illustrates noise data
during cylinder deactivation operation with the NVH torque limit control
method activated and without the NVH torque limit control activated. Sound
pressure levels in decibels (dB) are shown along the y-axis at 200. Engine
speed in RPM is shown along the x-axis at 210. Sound pressure level data
obtained without the NVH torque limit method activated is shown at 220.

GP 307894-PTE-CD
7
Sound pressure level data obtained with the NVE torque limit method
activated is shown at 230. The target NVH level is shown at 240. It can
easily be seen that the NVH limit is noticeable improvement over the unlimited
operation with respect to the target NVH.
[0024] Those skilled in the art can now appreciate from the
foregoing description that the broad teachings of the present disclosure can
be implemented in a variety of forms. Therefore, while this disclosure has
been described in connection with particular examples thereof, the true scope
of the disclosure should not be so limited since other modifications will
become apparent to the skilled practitioner upon a study of the drawings,
specification, and the following claims.

GP 307894-PTE-CD
8
CLAIMS
What is claimed is:
1. An engine control system for controlling the engine to transition
between an activated mode where all cylinders are active and a deactivated
mode where less than all cylinders are active, comprising:
a noise vibration and harshness (NVH) limit module that
determines a noise, vibration, and harshness (NVH) torque limit based on the
engine speed and the vehicle speed; and
a mode transition module that enables the engine to transition
between the deactivated mode and the activated mode while limiting noise,
vibration, and harshness based on the NVH torque limit and a requested
torque.
2. The system of claim 1 wherein the mode transition module
enables the engine to transition from the activated mode to the deactivated
mode based on the NVH torque limit, a hysteresis, and the requested torque.
3. The system of claim 1 wherein the mode transition module
commands the transition from the deactivated mode to the activated mode if
the requested torque is greater than the NVH torque limit.
4. The system of claim 1 wherein the mode transition module
commands the transition from the deactivated mode to the activated mode if
the requested torque is equal to the NVH torque limit.
5. The system of claim 2 wherein the mode transition module
enables the transition from the activated mode to the deactivated mode if the
requested torque is less than the NVH torque limit minus the hysteresis.

GP 307894-PTE-CD
9
6. The system of claim 4 wherein the mode transition module
enables the transition from the activated mode to the deactivated mode if
engine deactivation enable conditions are met.
7. The system of claim 1 wherein the mode transition module
determines the requested torque based on an accelerator pedal position.
8. The method of claim 1 wherein the NVH limit module determines
the NVH torque limit based on an interpolation of values stored in a two
dimensional table defined by indices of engine speed and vehicle speed.
9. A method of controlling an internal combustion engine to
transition between an activated mode where all cylinders are active and a
deactivated mode where less than all cylinders are active, comprising:
determining a noise, vibration, and harshness (NVH) torque limit
based on engine speed and vehicle speed; and
controlling the engine to transition from the deactivated mode to
the activated mode while limiting NVH if a requested torque is greater than the
NVH torque limit.
10. The method of claim 9 further comprising controlling the engine
to transition from the deactivated mode to the activated mode if the requested
torque is equal to the NVH torque limit.
11. The method of claim 9 further comprising controlling the engine
to transition from the activated mode to the deactivated mode if the requested
torque is less than the NVH torque limit minus a hysteresis.
12. The method of claim 11 further comprising controlling the engine
to transition from the activated mode to the deactivated mode if engine
deactivation enable conditions are met.

GP 307894-PTE-CD
10
13. The method of claim 9 further comprising determining the
requested torque from an accelerator pedal position.
14. The method of claim 9 wherein the determining comprises
determining the NVH torque limit based on interpolating values from a two
dimensional table defined by indices of engine speed and vehicle speed.
15. A method of controlling an internal combustion engine to
transition between an activated mode where all cylinders are active and a
deactivated mode where less than all cylinders are active, comprising:
determining a noise, vibration, and harshness (NVH) torque limit
based on engine speed and vehicle speed; and
controlling the engine to transition from the activated mode to
the deactivated mode while limiting NVH if a requested torque is less than the
NVH torque limit minus a hysteresis.
16. The method of claim 15 wherein the controlling comprises
controlling the engine to transition from the activated mode to the deactivated
mode if the requested torque is less than the NVH torque limit minus a
hysteresis and if engine deactivation enable conditions are met.
17. The method of claim 15 further comprising determining the
requested torque from an accelerator pedal position.
18. The method of claim 15 wherein the determining comprises
determining the NVH torque limit based on interpolating values from a two
dimensional table defined by indices of engine speed and vehicle speed.

An engine control system for controlling the engine to transition
between an activated mode where all cylinders are active and a deactivated
mode where less than all cylinders are active is provided. The system
includes: a noise vibration and harshness (NVH) limit module that determines
a noise, vibration, and harshness (NVH) torque limit based on the engine
speed and the vehicle speed; and a mode transition module that enables the
engine to transition between the deactivated mode and the activated mode
while limiting noise, vibration, and harshness based on the NVH torque limit
and a requested torque.

Documents:

01215-kol-2007-abstract.pdf

01215-kol-2007-assignment.pdf

01215-kol-2007-claims.pdf

01215-kol-2007-correspondence others 1.1.pdf

01215-kol-2007-correspondence others 1.2.pdf

01215-kol-2007-correspondence others 1.3.pdf

01215-kol-2007-correspondence others.pdf

01215-kol-2007-description complete.pdf

01215-kol-2007-drawings.pdf

01215-kol-2007-form 1.pdf

01215-kol-2007-form 18.pdf

01215-kol-2007-form 2.pdf

01215-kol-2007-form 3.pdf

01215-kol-2007-form 5.pdf

01215-kol-2007-priority document.pdf

1215-KOL-2007-ABSTRACT.pdf

1215-kol-2007-amanded claims.pdf

1215-KOL-2007-ASSIGNMENT.pdf

1215-KOL-2007-CORRESPONDENCE 1.6.pdf

1215-KOL-2007-CORRESPONDENCE OTHERS 1.4.pdf

1215-KOL-2007-CORRESPONDENCE-1.5.pdf

1215-KOL-2007-DESCRIPTION (COMPLETE).pdf

1215-KOL-2007-DRAWINGS.pdf

1215-KOL-2007-EXAMINATION REPORT.pdf

1215-KOL-2007-FORM 1.pdf

1215-KOL-2007-FORM 18.pdf

1215-KOL-2007-FORM 2.pdf

1215-KOL-2007-FORM 26.pdf

1215-KOL-2007-FORM 3.pdf

1215-KOL-2007-FORM 5.pdf

1215-KOL-2007-GRANTED-ABSTRACT.pdf

1215-KOL-2007-GRANTED-CLAIMS.pdf

1215-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1215-KOL-2007-GRANTED-DRAWINGS.pdf

1215-KOL-2007-GRANTED-FORM 1.pdf

1215-KOL-2007-GRANTED-FORM 2.pdf

1215-KOL-2007-GRANTED-LETTER PATENT.pdf

1215-KOL-2007-GRANTED-SPECIFICATION.pdf

1215-KOL-2007-OTHERS 1.1.pdf

1215-KOL-2007-OTHERS.pdf

1215-KOL-2007-PETITION UNDER RULE 137.pdf

1215-KOL-2007-REPLY TO EXAMINATION REPORT 1.1.pdf

1215-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

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Patent Number

250737

Indian Patent Application Number

1215/KOL/2007

PG Journal Number

04/2012

Publication Date

27-Jan-2012

Grant Date

23-Jan-2012

Date of Filing

31-Aug-2007

Name of Patentee

GM GLOBAL TECHNOLOGY OPERATIONS, INC

Applicant Address

300 GM RENAISSANCE CENTER DETROIT, MICHIGAN

Inventors:

#	Inventor's Name	Inventor's Address
1	KEVIN C. WONG	1503 SCIO RIDGE ROAD ANN ARBOR, MICHIGAN 48103
2	WILLIAM R. VENNER III	564 DORCHESTER WAY MILFORD, MICHIGAN 48381
3	ALFRED E. SPITZA JR.	3151 EDEN TRAIL BRIGHTON, MICHIGAN 48144

PCT International Classification Number

F02B75/06; F02D13/06; F02B75/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	11/530,688	2006-09-11	U.S.A.