Title of Invention

A METHOD FOR TRANSMISSION OF A CONTROLLING VEHICLE THROUGH INHIBITING A SHIFT IN OPPOSITE DIRECTION OF THE MOVING VEHICLE

Abstract The invention relates to a method for controlling a transmission of a vehicle having an engine, wheels, and a powertrain control module (PCM) in communication with the transmission, wherein one side of the transmission is connected to the engine and the other side is connected to a transmission output shaft which transfers an actual transmission output speed to the wheels, the method comprising recording, via the PCM, a threshold transmission output speed; detecting the actual output speed of the transmission using a speed sensor; detecting a shift request of the transmission in the direction opposite that of the direction of travel of the vehicle using a shift sensor; using the PCM to compare said detected actual output speed to said threshold transmission output speed; and executing, via the PCM a first pedal progression map in the direction of travel; a second pedal progression map in a direction opposite the direction of travel for which the first pedal progression map is executed when said detected actual output speed is less than or equal to said threshold transmission output speed; a set of shift inhibit limits, which are imposed on the second pedal progression map prior to executing the second pedal progression map and prior to executing the shift request, when said detected actual output speed is greater than said threshold transmission output speed; and the shift request after reaching the threshold transmission output speed, thereafter continuing to operate according to the second pedal progression map; wherein said shift inhibit limits inhibit a shift of the transmission by providing a gradual and controlled deceleration of the vehicle in response to said shift request by slowing the vehicle to below said threshold transmission output speed.
Full Text

FIELD OF THE INVENTION
The present invention pertains generally to a vehicle transmission control method
enabling a smooth forward or reverse shifting event, particularly to a method for
inhibiting an immediate shifting event or gear shift when an operator of a vehicle
requests a shifting event in a direction opposite the vehicle's direction of travel, and
more particularly to a method for transmission of a controlling vehicle through inhibiting
a shift in opposite a shift in opposite direction of the moving vehicle.
BACKGROUND OF THE INVENTION
Vehicle transmissions include various gear positions or settings, commonly denoted as
PRNDL for park, reverse, neutral, drive, and low drive, respectively. The PRNDL settings
are selectable by a vehicle operator by moving a shift lever or other shift mechanism to
thereby command or initiate a shift request. When shifting into reverse, for example,
conventional or mechanically geared vehicle transmissions generally require moving or
shifting a gear arrangement into a particular configuration suitable only for the reverse
operation, i.e. vehicle propulsion in the rearward direction. With such conventional
transmissions, the engine, which rotates or spins in only one direction, must provide
rotational force or torque to propel the vehicle in both forward and reverse operating
directions. Thus, reverse gearing must be configured to alter the direction of engine
rotation at the output of the transmission.
Therefore, with conventional transmissions the reverse shift is prevented under certain
circumstances. For example, if the vehicle is moving forward at a particular speed in
excess of a predetermined threshold speed, reverse shifts may be disabled or prevented
so as to protect the engine and/or transmission from excessive shift shock. Likewise,
when the vehicle is traveling at a relatively high rate of speed in a reverse direction, a
"forward/drive" shift request may be disabled or prevented. Such shift control
functionality may be provided using integrated transmission controls or other methods
and/or control devices suitable for preventing the shifting event.

In contrast to vehicles having a conventional transmission, hybrid vehicles are
alternately or concurrently powered by an engine and/or one or more electric
motor/generators, with forward and reverse operations typically achieved without
specific gearing changes or shifting. In such hybrid transmissions, forward and reverse
operations are achieved with the same mechanical configuration within the transmission.
For example, "forward/drive" is achieved by commanding transmission output torque in
a positive direction, while "reverse" is achieved by commanding transmission output
torque in a negative direction. Therefore, unlike many conventional transmissions,
hybrid transmissions may execute a reverse shift under limited forward operating
conditions, or a forward shift under limited reverse operating conditions. However, both
conventional and hybrid transmission control methodologies may be less than optimal
when operating under certain drive conditions, particularly when the vehicle is traveling
at a relatively high rate of speed.
SUMMARY OF THE INVENTION
Accordingly, a method is provided for controlling a vehicle transmission including
recording a threshold transmission output speed, detecting the actual output speed of
the transmission, detecting a shift request, comparing the detected and threshold output
speeds, and executing a normal pedal progression map when the detected output speed
is less than or equal to the threshold output speed. The method also executes a pair of
inhibit limits or curves when the detected output speed is greater than the threshold
output speed. The inhibit limits are configured to inhibit or delay a shift in the direction
opposite the direction of travel when the detected output speed exceeds the threshold
output speed by slowing the vehicle until the detected output speed drops below the
threshold output speed.
In one aspect of the invention, the method includes configuring the vehicle with a speed
sensor, a shift sensor, and a powertrain control module (PCM), sensing the transmission
output speed using the speed sensor and relaying the detected output speed to the
PCM, and sensing the shift request using the shift sensor and relaying the detected shift
request to the PCM.

In another aspect of the invention, the inhibit limits gradually slow the transmission
output speed to zero upon detection of the shift request, and the PCM executes a
corresponding forward or reverse pedal progression map to enable a shift upon reaching
the threshold output speed.
In another aspect of the invention, the inhibit limits gradually approach zero output
torque as vehicle speed increases, reaching zero output torque at a relatively high rate
of vehicle speed, thereby simulating a neutral condition of the transmission upon a
detected shift request at a relatively high rate of forward or reverse vehicle speed.
In another aspect of the invention, a vehicle is provided having a transmission with a
detectable actual output speed, a speed sensor operable for detecting the actual output
speed, a shift sensor operable for detecting a shift request, and a PCM having a stored
threshold output speed value. The PCM has a stored algorithm for inhibiting an
immediate shift when the shift request is in the direction opposite the direction of
vehicle travel and when the detected actual output speed is greater than the stored
threshold output speed value.
In another aspect of the invention, the vehicle includes a forward and reverse set of
shift inhibit limits. The PCM is operable for selecting the forward set when the detected
output speed is greater than the stored threshold output speed value and the vehicle is
traveling in the reverse direction, and for selecting the reverse set of inhibit limits when
the detected output speed is greater than the stored threshold output speed value and
the vehicle is traveling in the forward direction.
In another aspect of the invention, the inhibit limits gradually approach zero output
torque as the vehicle speed increases, reaching zero output torque at a relatively high
rate of vehicle speed, thereby simulating a neutral condition upon detecting a shift
request at a relatively high rate speed.
The above features and 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 ACCOMPANYING DRAWINGS
FIG. 1 is a schematic graphical illustration of a vehicle in accordance with the present
invention;
FIG. 2 is a schematic flow chart illustrating the preferred method or algorithm of the
invention;
FIG. 3 is a schematic graphical representation of a forward pedal progression map
having a set of forward shift inhibit limits; and
FIG. 4 is a schematic graphical representation of a reverse pedal progression map
having a set of reverse shift inhibit limits.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein like reference numbers refer to like components,
there is shown in FIG. 1 a schematic illustration of a vehicle 10 in accordance with the
present invention. Vehicle 10 includes an engine 12 having an engine output shaft 13
operatively connected to a transmission 14. The transmission 14 may be a conventional
or mechanical/geared transmission, a continuously variable transmission, or alternately
may be a hybrid transmission having includes at least one electric motor/generator 16,
shown in phantom in FIG. 1 and represented therein as "M/G" for simplicity. In such an
alternate hybrid configuration, motor/generator 16 is powered by an energy storage
device (ESD) 18, for example a rechargeable battery or battery pack, when
motor/generator 16 is acting in its capacity as a motor, and is operable for recharging
ESD 18 when operating in its capacity as a generator. Transmission output shaft 17
imparts or transfers an actual transmission output speed, represented as arrow N0, to a
set of wheels 19 to thereby propel or drive vehicle 10.
A controller or powertrain control module (PCM) 22 is operatively connected to engine
12 and transmission 14. PCM 22 is in communication with the transmission 14 by way of
a speed sensor 11 and a shift sensor 15, with sensors 11 and 15 being respectively
configured, adapted, and/or programmed to sense the actual transmission output speed
(N0) and a transmission shift request, such as an attempted movement of a gear shift
mechanism (not shown). PCM 22 further includes memory 26 having a control method
50 (see FIG. 2), as described hereinbelow,

which is configured or programmed to execute a shifting event, i.e. a shift into
"forward/drive" or "reverse", when vehicle 10 is operating or traveling in the direction
opposite that of the intended shift. That is, the method 50 inhibits an immediate or
instantaneous shift into "forward/drive" or "reverse" by executing a gradual, controlled
deceleration of vehicle 10 when a driver or operator of vehicle 10 selects or attempts to
shift to "forward/drive" or "reverse" during a relatively high rate of vehicle speed in the
opposite direction. The period of gradual deceleration is then sustained until a threshold
transmission output speed value is reached, at which point PCM 22 can launch or
execute the shifting event, and then proceed to execute previously stored or
programmed forward and reverse pedal progression maps, as will be described later
hereinbelow. The rate of deceleration is preferably selected to provide optimal comfort
to a vehicle occupant, and also preferably low enough such that the engine 12 and
transmission 14 are not subjected to excessive force or shift shock.
Turning to FIG. 3, a forward pedal progression map 30 is shown that may be used with
vehicle 10 of the present invention when vehicle 10 is operating in a "forward/drive"
condition. In forward map 30, "output torque" is arranged or positioned along the Y-
axis, and "vehicle speed" is arranged or positioned along the X-axis. As will be
understood by those of ordinary skill in the art, a "pedal progression map" is a map of
the amount of axle or transmission output torque requested or commanded for a
particular accelerator position and/or a particular vehicle speed. Such pedal progression
maps are commonly embodied as two-dimensional lookup tables which may be rapidly
accessed by a controller such as PCM 22 of the present invention. Forward map 30 is
bounded from above by 100% or fully depressed accelerator pedal position (curve 31),
i.e. "full open" throttle, and from below by 0% accelerator pedal position (curve 32).
The shape of curves 31 and 32 may be contoured according to the specific design
parameters of transmission 14 (see FIG. 1), and therefore may vary depending on the
design of the transmission 14. However, regardless of transmission design, curves 31
and 32 generally define four pedal progression regions 34, 36, 38, 39 with respect to the
intersecting X and Y axis.

Region 34 describes a first "rollback" region or operating condition. Region 34 is a region
in which an increasing torque is commanded in the direction of intended, i.e. forward,
motion as vehicle 10 increases its speed in the direction opposite the intended motion.
For example, rollback region 34 may execute when vehicle 10 is rolling backward with
transmission 14 in "drive". While in region 34, PCM 22 commands an increasing torque
suitable for slowing the rate of rollback.
Next, region 36, which is the largest region of forward map 30, represents a
"propulsion" operating condition. Region 36 is a region in which torque is commanded in
the direction of intended motion to thereby accelerate vehicle 10 or to maintain an
existing speed. As vehicle speed increases, the output torque required to maintain
vehicle speed eventually drops to a relatively constant value, as indicated by the shape
of curve 31. Below propulsion region 36, and below the X-axis, is a third or "drag"
region 38. Region 38 is a region or operating condition in which torque is commanded
opposite the direction of intended motion in order to slow vehicle 10 when the
accelerator pedal (not shown) is near zero or unapplied, in order to simulate a condition
of engine drag.
Finally, region 39 represents a "creep region", or a region or operating condition in
which a small amount of torque is commanded in the direction of intended motion
during relatively low vehicle speeds and low accelerator pedal apply level or percentage
of apply capacity, so that vehicle 10 moves in the intended direction. For example, creep
region 39 may be entered when vehicle 10 is executing low speed maneuvers, such as
while entering a garage.
Turning to FIG. 2, the method 50 of the invention preferably initiates upon start-up of
vehicle 10. Beginning with step 52, algorithm 50 detects the actual transmission output
speed (N0) of transmission output 17, and temporarily stores or records the detected
output speed (No) in memory 26. Detection of transmission output speed (N0) may be
accomplished using one or more speed sensors 11, which mechanically and/or
electrically detect transmission output speed (N0) and transmit the measured or
detected speed value to PCM 22. Speed sensor 11 is any sensor equipped to directly
and/or indirectly detect or sense the actual transmission output speed (N0), such as by
detecting a throttle command or pedal

position/percent of apply of a vehicle throttle or accelerator pedal (not shown), and/or
by directly or indirectly measuring rotational speed of transmission output 17. After
transmission output speed (N0) has been detected, algorithm 50 then proceeds to step
54.
In step 54, algorithm 50 detects a shift request, i.e. an operator-initiated request to shift
the transmission 14 (see FIG. 1) into "forward/drive" or "reverse" when vehicle 10 is
traveling in a direction opposite that of the requested shift. Detection of a shift request
may be accomplished using one or more shift sensors 15 which mechanically and/or
electrically detect the shift request and transmit the detected shift request to PCM 22,
where it is temporarily stored or recorded in memory 26. If no shift request is detected,
the method 50 remains in step 54, and in a "forward/drive" or "reverse" operating
condition according to forward map 30 (see FIG. 3) or reverse map 40 (see FIG. 4),
respectively, until such a shift request is detected. Once detected, the method 50
proceeds to step 56.
In step 56, the method 50 compares the detected actual transmission output speed (N0)
(see step 52) to a maximum or threshold transmission output speed, labeled in FIG. 2 as
Nt, which is stored in memory 26. Memory 26 of PCM 22 is preferably preloaded or
programmed with the threshold output speed value (Nt), which is preferably determined
during pre-production vehicle development and testing, and which may vary depending
on the specific design parameters of a given transmission 14. For example, in a
conventional transmission, it may be preferable to set the threshold output speed (Nt) at
zero to minimize shift shock, while a low but non-zero threshold output speed (Nt) may
be used in conjunction with a hybrid transmission. Threshold output speed (Nt) is a
speed below which algorithm 50 may efficiently and/or smoothly execute a forward or
reverse pedal progression map, as discussed later hereinbelow with reference to step 58
and FIG. 4, after executing the requested shifting event. If the detected transmission
output speed (N0) is less than or equal to the stored threshold output speed (Nt),
algorithm 50 proceeds to step 58. If, however, the detected transmission output speed
(N0) is greater than the threshold output speed (Nt), algorithm 50 proceeds to step 60.

In step 58, the method 50 executes a normal forward or reverse pedal progression map
30 and 40, respectively (see FIGS. 3 and 4, respectively), as determined by the direction
of travel of vehicle 10. That is, if vehicle 10 is traveling in "forward/drive", the pedal
progression is governed by forward map 30 (see FIG. 3), and likewise, if vehicle 10 is
traveling in "reverse", the pedal progression is governed by a reverse map 40 (see FIG.
4). The algorithm 50 then continues operating within forward map 30 or reverse map 40
until a shifting event in the opposite direction is requested.
In step 60, which as explained above is executed if the method 50 determines that the
detected transmission output speed (N0) is greater than the threshold output speed (Nt)
(see step 56), the method 50 executes or imposes a set of separate or virtual "shift
inhibit limits" before proceeding to step 58, with step 60 inhibiting or delaying the
immediate shifting event. Steps 58 and 60 are best described together, with reference
to FIGS. 3 and 4.
Turning to FIG. 4, a "reverse pedal progression map" or reverse map 40 according to
the invention is shown. As with the previously described forward map 30 of FIG. 3,
reverse map 40 is bounded from above by 100% or fully depressed accelerator pedal
position (curve 41), i.e. "full open" throttle, and bounded from below by 0% accelerator
pedal position (curve 42). The shape of curves 41 and 42 may be contoured according
to the specific design parameters of the transmission 14 (see FIG. 1). Reverse map 40
further includes an upper reverse inhibit limit or curve 45, and a lower reverse inhibit
limit or curve 47.
As those of ordinary skill in the art will appreciate, transitioning immediately from
forward map 30 of FIG. 3 to curves 41 and 42 of reverse map 40 (see FIG. 4)
immediately upon movement of a shift lever (not shown) from "forward/drive" to
"reverse" would not provide an optimally smooth and efficient shifting event under most
vehicle speeds above a minimal or zero predetermined threshold speed (Nt). Therefore,
in accordance with the invention, curves 45 and 47 are imposed on curves 41 and 42 of
map 40.

When vehicle 10 is moving in a forward direction according to forward map 30
and an operator selects or shifts to "reverse", PGM 22 selects reverse map 40,
and moves from forward map 30 of FIG. 3 to reverse map 40 of FIG. 4 at the
same vehicle speed. However, rather than attempting to directly apply or
execute reverse map 40 under the same output torque, PGM 22 instead applies a
gradually increasing negative torque along following curves 45 and 47 to
counteract the positive torque of transmission output 17, and at a level that is
sufficient to produce an acceptable and/or comfortable rate of deceleration to
vehicle 10. In other words, PGM 22 utilizes the previously described algorithm 50
to impose curves 45 and 47 during positive speed conditions, and continues to
impose curves 45 and 47 to the exclusion of curves 41 and 42, until vehicle 10
reaches the threshold output speed value (Nt) (see step 56), at or near a zero
vehicle speed to thereby minimize any shift shock.
Curves 45 and 47 preferably flatten to or approach zero output torque at
progressively higher vehicle speeds, thereby simulating a "neutral" operating
condition at zero output torque and relatively high vehicle speeds. Once reaching
the threshold output speed (Nt), PGM 22 executes the requested shifting event
and continues operating according to reverse map 40. Within the scope of the
invention, PGM 22 may be calibrated as desired, such as by modifying curves 41,
42, 45, and 47, in order to produce the desired shift effect for transmission 14.
Finally, similar forward inhibit limits 35 and 37 may be applied in the event
vehicle 10 were to travel in a reverse direction at a high rate of speed, and an
operator were to attempt to shift into "forward/drive". In such an event, rather
than attempting to immediately switch to forward map 30 (see FIG. 3) at the
corresponding vehicle speed point, a set of forward inhibit limits or curves 35
and 37 would be imposed. Once curves 35 and 37 have slowed or reduced the
reverse speed below the threshold speed (Nt), PCM 22 (see FIG. 1) may then
execute a shifting event into "forward/drive" and continue operating according to
forward map 30, as previously described hereinabove.

In this manner, the method 50 may provide a smooth shifting event or transition
between "reverse" and "forward/drive", and vice versa, when the vehicle 10 is
moving, while maintaining propulsion capability throughout the transition, and
even when the transition is made at a relatively high rate of speed. Additionally,
method 50 provides for improved "rock cycles" when an operator attempts to
alternately "rock" a vehicle forward and backward, such as when attempting to
gain traction, since seamless transitions are enabled from "forward/drive" to
"reverse" and back.
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 disclosure.

WE CLAIM
1. A method for controlling a transmission of a vehicle having an engine,
wheels, and a powertrain control module (PCM) in communication with
the transmission, wherein one side of the transmission is connected to the
engine and the other side is connected to a transmission output shaft
which transfers an actual transmission output speed to the wheels, the
method comprising:
recording, via the PCM, a threshold transmission output speed;
detecting the actual output speed of the transmission using a speed
sensor; detecting a shift request of the transmission in the direction
opposite that of the direction of travel of the vehicle using a shift sensor;
using the PCM to compare said detected actual output speed to said
threshold transmission output speed; and
executing, via the PCM:
a first pedal progression map in the direction of travel;
a second pedal progression map in a direction opposite the
direction of travel for which the first pedal progression map is
executed when said detected actual output speed is less than or
equal to said threshold transmission output speed;
a set of shift inhibit limits, which are imposed on the second pedal
progression map prior to executing the second pedal progression
map and prior to executing the shift request, when said detected
actual output speed is greater than said threshold transmission
output speed; and

the shift request after reaching the threshold transmission output
speed, thereafter continuing to operate according to the second
pedal progression map;
wherein said shift inhibit limits inhibit a shift of the transmission by
providing a gradual and controlled deceleration of the vehicle in
response to said shift request by slowing the vehicle to below said
threshold transmission output speed.
2. The method as claimed in claim 1, wherein said transmission is a hybrid
transmission.
3. The method as claimed in claim 1, wherein said PCM is further configured
for:
executing said shift inhibit limits by gradually slowing said actual
transmission output speed to zero upon said detection of said shift
request; and
executing said pedal progression map upon reaching said zero
output speed, thereby enabling a smooth shifting event in response
to said detected shift request.
4. The method as claimed in claim 3, wherein said inhibit limits gradually
reduce the actual output torque of the transmission to approximately zero
as vehicle speed increases in a direction opposite that of the shift request,
reaching said approximately zero output torque prior to executing the shift
request, thereby simulating a neutral condition of the transmission.
5. A method for inhibiting a shift in one direction in a transmission of a
vehicle moving in the opposite direction, the vehicle having an engine,

wheels, and a controller in communication with the transmission, wherein
one side of the transmission is connected to the engine and the other side
transfers an actual transmission output speed to the wheels via a
transmission output shaft, the method comprising:
recording a threshold transmission output speed in said controller;
detecting the actual output speed of the transmission;
detecting a shift request in said one direction;
configuring the controller with a forward pedal progression map having a
set of forward shift inhibit limits, and with a reverse pedal progression
map having a set of reverse shift inhibit limits, said controller being
configured to execute a shift of the transmission in said one direction in
response to said shift request;
comparing said detected actual output speed to said threshold output
speed; and
executing, via the controller, said forward inhibit limits, which are imposed
on the forward pedal progression map prior to executing the forward
pedal progression map and the shift request, when the opposite direction
is the reverse direction, said detected actual output speed is greater than
said threshold transmission output speed, and said one direction is the
reverse direction;
executing, via the controller, said reverse inhibit limits, which are imposed
on the reverse pedal progression map prior to executing the reverse pedal
progression map and the shift request, when the opposite direction is the
forward direction, said detected actual output speed is greater than said
threshold transmission output speed, and the one direction is the forward
direction; and

executing, via the controller, the shift request after reaching the threshold
transmission output speed, thereafter continuing to operate according to
the forward pedal progression map when the shift request is in the
forward direction, and according to the reverse pedal progression map
when the shift request is in the reverse direction,
wherein said forward and said reverse shift inhibit limits inhibit an a
immediate shift of the transmission by providing a gradual and controlled
deceleration of the vehicle in response to said shift request by slowing the
vehicle to below said threshold transmission output speed.
6. The method as claimed in claim 5, wherein said transmission is a hybrid
transmission.
7. The method as claimed in claim 5, wherein said executing said forward
and said reverse inhibit limits are configured to gradually slow the vehicle
until said detected actual output speed reaches zero.
8. The method as claimed in claim 6, comprising configuring the vehicle with
at least one speed sensor and at least one shift sensor, wherein said
detecting said actual transmission output speed comprises sensing said
actual transmission output speed using said at least one speed sensor and
relaying said detected actual transmission output speed to said controller,
and wherein said detecting a shift request comprises sensing said shift
request using said at least one shift sensor and relaying said detected
shift request to said controller.
9. A vehicle comprising: an engine;
a transmission connected on one side to the engine, and having a

transmission output shaft on another side, wherein the transmission
output shaft has a detectable actual output speed;
a speed sensor operable for detecting said actual output speed; a shift
sensor operable for detecting a shift request in the direction opposite the
direction of vehicle travel; and
a powertrain control module (PCM) having a stored threshold output
speed value and an algorithm enabling a smooth shift event upon
detection of said shift request when said detected actual output speed is
greater than said threshold transmission output speed;
wherein the PCM is configured to:
automatically compare said detected actual output speed to said stored
threshold output speed value;
execute a first pedal progression map in the direction of travel; execute a
second pedal progression map in the direction opposite the direction of
travel for which the first pedal progression map is used when said
detected actual output speed is less than or equal to said threshold output
speed value;
impose a set of shift inhibit limits on the second pedal progression map,
prior to executing the second pedal progression map and prior to
executing the shift request, when said detected actual output speed is
greater than said threshold transmission output speed; and
execute the shift event after executing the set of shift limits and after
reaching the threshold transmission output speed, thereafter operating
according to the second pedal progression map.

10. The vehicle as claimed in claim 9, comprising a forward and a reverse set
of shift inhibit limits, wherein said PCM is operable for selecting said
forward set of inhibit limits when said detected actual output speed is
greater than said threshold transmission output speed and said direction
of vehicle travel is the reverse direction, and for selecting said reverse set
of shift inhibit limits when said detected actual output speed is greater
than said threshold transmission output speed and said direction of
vehicle travel is the forward direction.
11.The vehicle as claimed in claim 10, wherein each of said sets of inhibit
limits approach zero output torque as the vehicle speed increases,
reaching said zero output torque at a relatively high rate of vehicle speed,
thereby simulating a neutral condition of said transmission upon said
detected shift request at said relatively high rate of vehicle speed.
12. The vehicle as claimed in claim 11, wherein said transmission is a hybrid transmission.



ABSTRACT


TITLE : "A METHOD FOR TRANSMISSION OF A CONTROLLING VEHICLE
THROUGH INHIBITING A SHIFT IN OPPOSITE DIRECTION OF THE
MOVING VEHICLE"
The invention relates to a method for controlling a transmission of a vehicle
having an engine, wheels, and a powertrain control module (PCM) in
communication with the transmission, wherein one side of the transmission is
connected to the engine and the other side is connected to a transmission output
shaft which transfers an actual transmission output speed to the wheels, the
method comprising recording, via the PCM, a threshold transmission output
speed; detecting the actual output speed of the transmission using a speed
sensor; detecting a shift request of the transmission in the direction opposite
that of the direction of travel of the vehicle using a shift sensor; using the PCM
to compare said detected actual output speed to said threshold transmission
output speed; and executing, via the PCM a first pedal progression map in the
direction of travel; a second pedal progression map in a direction opposite the
direction of travel for which the first pedal progression map is executed when
said detected actual output speed is less than or equal to said threshold
transmission output speed; a set of shift inhibit limits, which are imposed on the
second pedal progression map prior to executing the second pedal progression
map and prior to executing the shift request, when said detected actual output
speed is greater than said threshold transmission output speed; and the shift
request after reaching the threshold transmission output speed, thereafter
continuing to operate according to the second pedal progression map; wherein
said shift inhibit limits inhibit a shift of the transmission by providing a gradual
and controlled deceleration of the vehicle in response to said shift request by
slowing the vehicle to below said threshold transmission output speed.

Documents:

00285-kol-2008-abstract.pdf

00285-kol-2008-claims.pdf

00285-kol-2008-correspondence others.pdf

00285-kol-2008-description complete.pdf

00285-kol-2008-drawings.pdf

00285-kol-2008-form 1.pdf

00285-kol-2008-form 2.pdf

00285-kol-2008-form 3.pdf

00285-kol-2008-form 5.pdf

285-KOL-2008-(16-01-2013)-ABSTRACT.pdf

285-KOL-2008-(16-01-2013)-CLAIMS.pdf

285-KOL-2008-(16-01-2013)-CORRESPONDENCE.pdf

285-KOL-2008-(16-01-2013)-DESCRIPTION (COMPLETE).pdf

285-KOL-2008-(16-01-2013)-DRAWINGS.pdf

285-KOL-2008-(16-01-2013)-FORM 1.pdf

285-KOL-2008-(16-01-2013)-FORM 2.pdf

285-KOL-2008-(16-01-2013)-FORM 3.pdf

285-KOL-2008-(16-01-2013)-OTHERS.pdf

285-KOL-2008-(16-01-2013)-PA.pdf

285-KOL-2008-(16-01-2013)-PETITION UNDER RULE 137.pdf

285-KOL-2008-ABSTRACT.pdf

285-KOL-2008-ASSIGNMENT-1.1.pdf

285-KOL-2008-ASSIGNMENT.pdf

285-KOL-2008-CANCELLED PAGES-1.1.pdf

285-KOL-2008-CANCELLED PAGES.pdf

285-KOL-2008-CLAIMS.pdf

285-KOL-2008-CORRESPONDENCE OTHERS 1.1.pdf

285-KOL-2008-CORRESPONDENCE OTHERS 1.2.pdf

285-KOL-2008-CORRESPONDENCE-1.1.pdf

285-KOL-2008-CORRESPONDENCE.pdf

285-KOL-2008-DESCRIPTION (COMPLETE).pdf

285-KOL-2008-DRAWINGS.pdf

285-KOL-2008-EXAMINATION REPORT.pdf

285-KOL-2008-FORM 1.pdf

285-KOL-2008-FORM 18-1.1.pdf

285-kol-2008-form 18.pdf

285-KOL-2008-FORM 2.pdf

285-KOL-2008-FORM 3.pdf

285-KOL-2008-GPA-1.1.pdf

285-KOL-2008-GPA.pdf

285-KOL-2008-GRANTED-ABSTRACT.pdf

285-KOL-2008-GRANTED-CLAIMS.pdf

285-KOL-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

285-KOL-2008-GRANTED-DRAWINGS.pdf

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

285-KOL-2008-GRANTED-FORM 2.pdf

285-KOL-2008-GRANTED-FORM 3.pdf

285-KOL-2008-GRANTED-FORM 5.pdf

285-KOL-2008-GRANTED-SPECIFICATION-COMPLETE.pdf

285-KOL-2008-OTHERS-1.1.pdf

285-KOL-2008-OTHERS.pdf

285-KOL-2008-PETITION UNDER RULE 137-1.1.pdf

285-KOL-2008-PETITION UNDER RULE 137.pdf

285-KOL-2008-PRIORITY DOCUMENT.pdf

285-KOL-2008-REPLY TO EXAMINATION REPORT-1.1.pdf

285-KOL-2008-REPLY TO EXAMINATION REPORT.pdf

285-KOL-2008-SPECIFICATION.pdf

285-KOL-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

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Patent Number 259601
Indian Patent Application Number 285/KOL/2008
PG Journal Number 12/2014
Publication Date 21-Mar-2014
Grant Date 19-Mar-2014
Date of Filing 18-Feb-2008
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Applicant Address 300 GM RENAISSANCE CENTER DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 WILLIAM R. CAWTHORNE 595 RIVER OAKS DRIVE MILFORD, MICHIGAN 48381
2 LEONARD G. WOZNIAK 1055 BANDERA DRIVE ANN ARBOR, MICHIGAN 48103
PCT International Classification Number F16H59/38; F16H59/02; F16H59/38
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/684,055 2007-03-09 U.S.A.