U.S. patent application number 15/041374 was filed with the patent office on 2017-08-17 for line lock braking system and method for a vehicle.
The applicant listed for this patent is Jeremy J. Anker, Farhan Ehsan, Paul Rodriguez, Jeffrey Uehlein, James M. Wilder. Invention is credited to Jeremy J. Anker, Farhan Ehsan, Paul Rodriguez, Jeffrey Uehlein, James M. Wilder.
Application Number | 20170232968 15/041374 |
Document ID | / |
Family ID | 59561182 |
Filed Date | 2017-08-17 |
United States Patent
Application |
20170232968 |
Kind Code |
A1 |
Wilder; James M. ; et
al. |
August 17, 2017 |
LINE LOCK BRAKING SYSTEM AND METHOD FOR A VEHICLE
Abstract
A line lock braking system includes a brake module configured to
selectively apply hydraulic braking pressure against first wheels
and second wheels of the vehicle, and a controller in signal
communication with the brake module. The controller initiates, upon
receipt of a request, a vehicle line lock mode and performs line
lock braking of the vehicle where the brake module is controlled to
selectively apply braking pressure against the first wheels and not
the second wheels such that the second wheels are free to rotate
based on a throttle applied by a driver; completes the line lock
mode upon release of a button being depressed to enter and maintain
activation of the line lock mode such that the braking pressure
against the first wheels is released; and cancels the line lock
mode upon determining a number of rotations of the second wheels
exceeds a predetermined number of wheel rotations.
Inventors: |
Wilder; James M.;
(Farmington Hills, MI) ; Anker; Jeremy J.; (Lake
Orion, MI) ; Uehlein; Jeffrey; (Farmington Hills,
MI) ; Rodriguez; Paul; (White Lake, MI) ;
Ehsan; Farhan; (Windsor, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wilder; James M.
Anker; Jeremy J.
Uehlein; Jeffrey
Rodriguez; Paul
Ehsan; Farhan |
Farmington Hills
Lake Orion
Farmington Hills
White Lake
Windsor |
MI
MI
MI
MI |
US
US
US
US
CA |
|
|
Family ID: |
59561182 |
Appl. No.: |
15/041374 |
Filed: |
February 11, 2016 |
Current U.S.
Class: |
701/70 |
Current CPC
Class: |
B60T 8/26 20130101; B60T
8/266 20130101; B60T 8/1766 20130101; B60T 8/175 20130101 |
International
Class: |
B60W 30/18 20060101
B60W030/18; B60W 10/30 20060101 B60W010/30; B60W 10/184 20060101
B60W010/184 |
Claims
1. A line lock braking system for a vehicle, the system comprising:
a brake module integrated control unit (ICU) configured to
selectively apply hydraulic braking pressure against front wheels
and rear wheels of the vehicle; and a controller in signal
communication with the brake module, the controller configured to:
upon receipt of a request, initiate a vehicle line lock mode and
perform a line lock braking of the vehicle where the brake module
ICU is controlled to selectively apply hydraulic braking pressure
against the front wheels and not the rear wheels such that the rear
wheels are free to rotate based on a throttle applied by a driver
of the vehicle; monitor, during the vehicle line lock mode, a
number of rotations of the rear wheels while the front wheels are
maintained in a substantially stationary state by the brake module
ICU; upon release of a button being depressed to enter and maintain
activation of the vehicle line lock mode, complete the vehicle line
lock mode such that the braking pressure against the front wheels
is released; and deactivate the vehicle line lock mode upon
determining the number of rotations of the rear wheels exceeds a
predetermined number of wheel rotations during the vehicle line
lock mode.
2. The system of claim 1, wherein upon canceling the vehicle line
lock mode when the predetermined number of wheel rotations is
exceeded, the controller is configured to: control the brake module
ICU to apply hydraulic braking pressure against the rear
wheels.
3. The system of claim 1, further comprising a user interface in
signal communication with the controller, the controller configured
to receive the request from the user interface indicating the
driver has selected the vehicle line lock mode.
4. The system of claim 3, wherein the controller is configured to
prompt the driver to utilize the user interface to enter
information for use in determining the predetermined number of
wheel rotations, the information including at least one of a tire
type and a track or road surface temperature.
5. The system of claim 4, wherein during the vehicle line lock
mode, the controller is configured to cause the user interface to
display a real-time running count of the monitored number of
rotations of the rear wheels and, upon the monitored number of
wheel rotations of the rear wheels approaching the predetermined
number of rotations, the controller is configured to cause the user
interface to display a message indicating the vehicle line lock
mode will be canceled upon the monitored number of rotations of the
rear wheels exceeding the predetermined number of rotations.
6. The system of claim 3, further comprising the controller causing
the user interface to display a message indicating the vehicle line
lock mode has been canceled due to the predetermined number of
wheel rotations being exceeded.
7. The system of claim 3, wherein the predetermined number of wheel
rotations is between 300 rotations and 500 rotations.
8. The system of claim 3, wherein the controller is configured to
determine whether an initial vehicle precondition is satisfied
before enabling the vehicle to enter the vehicle line lock mode,
the initial precondition including at least one of: (a) a speed of
the vehicle is less than or equal to 10 MPH; (b) an engine RPM is
greater than 500 RPM; (c) a temperature of a transmission of the
vehicle is not over a predetermined temperature; (d) the engine is
running; (e) no current active electronic stability control (ESC)
faults are present; (f) a radiator coolant temperature is less than
approximately 250.degree. F.; (g) an odometer is greater than a
predetermined number; (h) a valet mode is not active; (i) vehicle
doors are closed; and (j) a cruise control is not enabled or
active.
9. The system of claim 3, wherein the controller is configured to
determine whether a secondary vehicle precondition is satisfied
before enabling the vehicle to enter the line lock braking mode,
the secondary vehicle precondition including at least one of: (i) a
speed of the vehicle is zero MPH; (ii) a brake pedal pressure is
greater than a predetermined pressure; (iii) a vehicle transmission
is in a forward gear; and (iv) a vehicle traction control is
off.
10. The system of claim 1, wherein the controller is configured to
deactivate the vehicle line lock mode if at least one of the
following occurs during the vehicle line lock mode: (1) wheel speed
sensors indicate the rear wheels have rotated more than the
predetermined number of wheel rotations; (2) an initial
precondition occurs; (3) a secondary precondition occurs; (4) a
vehicle brake pedal is depressed; (5) a vehicle accelerator pedal
is released; (6) the vehicle rotates beyond a predetermined angle;
and (7) a pressure of one of the rear wheels is less than or equal
to a predetermined minimum pressure.
11. A method of performing vehicle line lock braking, the method
comprising: receiving, at a controller, a request for a vehicle
line lock mode; initiating the vehicle line lock mode when the
request is received by applying hydraulic braking pressure against
front wheels and not rear wheels of the vehicle such that the rear
wheels are free to rotate based on a throttle applied by a driver
of the vehicle; monitoring, during the vehicle line lock mode, a
number of rotations of the rear wheels while the front wheels are
maintained in a substantially stationary state by a brake module
integrated control unit (ICU) of the vehicle; completing the
vehicle line lock mode, upon release of a button being depressed to
enter and maintain activation of the vehicle line lock mode, such
that the braking pressure against the front wheels is released; and
deactivating the vehicle line lock mode upon determining the number
of rotations of the rear wheels exceeds a predetermined number of
wheel rotations during the vehicle line lock mode.
12. The method of claim 11, wherein upon canceling the vehicle line
lock mode when the number of rotations of the rear wheels exceeds
the predetermined number of wheel rotations, the controller is
further configured to: control the brake module ICU to apply
hydraulic braking pressure against the rear wheels.
13. The method of claim 11, further comprising the controller
causing a user interface of the vehicle to display a message to
prompt the driver to utilize the user interface to enter
information for use in determining the predetermined number of
wheel rotations, the information including at least one of a tire
type and a track or road surface temperature.
14. The method of claim 11, further comprising the controller
causing a user interface of the vehicle to display a message
indicating the vehicle line lock mode has been canceled due to the
predetermined number of wheel rotations being exceeded.
15. The method of claim 11, further comprising, during the vehicle
line lock mode, the controller causing a user interface of the
vehicle to display a real-time running count of the monitored
number of rotations of the rear wheels and, upon the monitored
number of rotations of the rear wheels approaching the
predetermined number of wheel rotations, the controller causing the
user interface to display a message indicating the vehicle line
lock mode will be canceled upon the monitored number of rotations
of the rear wheels exceeding the predetermined number of wheel
rotations.
16. The method of claim 11, further comprising the controller
determining whether an initial vehicle precondition is satisfied
before enabling the vehicle to enter the vehicle line lock mode and
prevent initiation of the vehicle line lock mode if the initial
vehicle precondition is not satisfied, the initial vehicle
precondition including at least one of: (a) a speed of the vehicle
is less than or equal to 10 MPH; (b) an engine RPM is greater than
500 RPM; (c) a temperature of a transmission of the vehicle is not
over a predetermined temperature; (d) the engine is running; (e) no
current active electronic stability control (ESC) faults are
present; (f) a radiator coolant temperature is less than
approximately 250.degree. F.; (g) an odometer is greater than a
predetermined number; (h) a valet mode is not active; (i) vehicle
doors are closed; and (j) a cruise control is not enabled or
active.
17. The method of claim 16, further comprising: determining if a
secondary vehicle precondition is satisfied; preventing the vehicle
line lock mode if the secondary vehicle precondition is not
satisfied; and directing a driver to correct one or more
unsatisfied secondary vehicle preconditions if the secondary
vehicle precondition is not satisfied; wherein the secondary
vehicle precondition includes at least one of: (i) a speed of the
vehicle is zero MPH; (ii) a brake pedal pressure is greater than a
predetermined pressure; (iii) a vehicle transmission is in a
forward gear; and (iv) a vehicle traction control is off.
18. The method of claim 11, further comprising deactivating the
vehicle line lock mode if at least one of the following occurs
during the vehicle line lock mode: (1) wheel speed sensors indicate
the rear wheels have rotated more than the predetermined number of
wheel rotations; (2) an initial precondition occurs; (3) a
secondary precondition occurs; (4) a vehicle brake pedal is
pressed; (5) a vehicle accelerator pedal is released; (6) the
vehicle rotates beyond a predetermined angle; and (7) a pressure of
one of the rear wheels is less than or equal to a predetermined
minimum pressure.
Description
FIELD
[0001] The present application relates generally to a vehicle
braking system and, more particularly, to a vehicle braking system
for selectively providing a line lock condition.
BACKGROUND
[0002] In some vehicle launch scenarios, to increase performance of
the vehicle at take-off, drivers can perform a controlled spinning
of the rear tires (e.g., a burnout), which warms the tires and
improves grip with the road or track surface. However, in order to
perform the controlled burnout, a driver is typically required to
manipulate the service brake system to allow the rear wheels to
spin freely while the front wheels are held stationary by the brake
system. Moreover, the driver may be required to perform multiple
tasks such as simultaneously interacting with the throttle, brake,
and clutch, which may be difficult to safely or correctly
perform.
[0003] Aftermarket systems have been proposed to assist the driver
with the controlled burnout. However, some such systems pose
reliability issues and do not provide an automated, electrical
control of the burnout. Other brake line lock systems have been
developed for inclusion with the original vehicle equipment.
However, such systems have drawbacks including time-based controls
that prevent the controlled burnout after a certain period of time
even though the driver still desires to perform the action.
Accordingly, while such systems work for their intended purpose, it
is desirable to provide an improved vehicle line lock braking
system.
SUMMARY
[0004] In accordance with one example aspect of the invention, a
line lock braking system for a vehicle is provided. The line lock
braking system includes a brake module configured to selectively
apply hydraulic braking pressure against first wheels and second
wheels of the vehicle, and a controller in signal communication
with the brake module. The controller is configured to upon receipt
of a request, initiate a vehicle line lock mode and perform a line
lock braking of the vehicle where the brake module is controlled to
selectively apply hydraulic braking pressure against the first
wheels and not the second wheels such that the second wheels are
free to rotate based on a throttle applied by a driver of the
vehicle; monitor a number of wheel rotations of the second wheels
while the first wheels are maintained in a substantially stationary
state by the brake module; complete the vehicle line lock mode,
upon release of a button being depressed to enter and maintain
activation of the line lock mode, such that the braking pressure
against the first wheels is released; and cancel the vehicle line
lock mode upon determining the number of wheel rotations of the
second wheels exceeds a predetermined number of rotations during
the vehicle line lock mode.
[0005] According to another example aspect of the invention, a
method of performing vehicle line lock braking is provided. The
method includes receiving at a controller a request for a vehicle
line lock mode, initiating the vehicle line lock mode when the
request is received by applying hydraulic braking pressure against
first wheels and not second wheels of the vehicle such that the
second wheels are free to rotate based on a throttle applied by a
driver of the vehicle; and monitoring a number of wheel rotations
of the second wheels while the first wheels are maintained in a
substantially stationary state by a brake module. The vehicle line
lock mode is completed upon release of a button being depressed to
enter and maintain activation of the line lock mode, such that the
braking pressure against the first wheels is released; and the
vehicle line lock mode is canceled upon determining the number of
wheel rotations of the second wheels exceeds a predetermined number
of rotations during the vehicle line lock mode.
[0006] Further areas of applicability of the teachings of the
present disclosure will become apparent from the detailed
description, claims and the drawings provided hereinafter, wherein
like reference numerals refer to like features throughout the
several views of the drawings. It should be understood that the
detailed description, including disclosed embodiments and drawings
references therein, are merely exemplary in nature intended for
purposes of illustration only and are not intended to limit the
scope of the present disclosure, its application or uses. Thus,
variations that do not depart from the gist of the present
disclosure are intended to be within the scope of the present
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of an example vehicle in
accordance with the principles of the present disclosure;
[0008] FIG. 2 is a front view of an example driver control system
in accordance with the principles of the present disclosure;
[0009] FIG. 3 is a schematic view of an example vehicle control
system in accordance with the principles of the present disclosure;
and
[0010] FIG. 4 is a flow control diagram of an example method of
controlling a vehicle in accordance with the principles of the
present disclosure.
DETAILED DESCRIPTION
[0011] With initial reference to FIG. 1, an example vehicle is
illustrated and generally identified at reference numeral 10. The
vehicle 10 includes a line locking braking system configured to
selectively transition the vehicle from a normal mode to a line
lock braking mode where vehicle front wheels 20 are locked and a
braking pressure is selectively released on vehicle rear wheels 30.
This enables the driver to apply the throttle to rotate the rear
wheels 30 and perform a controlled burnout. Additionally, the
described line lock feature will deactivate when the rear wheels 30
have rotated a predetermined number of times, the driver manually
aborts the feature, or the vehicle/system detects a fault or error.
The vehicle then returns to the normal operating mode behavior
after the line lock feature has been deactivated.
[0012] With additional reference to FIG. 2, the vehicle 10 includes
a vehicle interior 40 having a driver control system 50, which
generally comprises a steering wheel 60, an instrument cluster 70,
and a display 80 having a user interface 90. The driver control
system 50 is in signal communication with the line locking braking
system, and enables the driver to activate and deactivate the line
lock braking mode. Moreover, in one exemplary implementation, the
driver control system 50 assists the driver in performing the
controlled burnout when the line lock braking mode is activated,
for example, through a sequence of audio and/or visual cues.
[0013] The steering wheel 60 may include one or more buttons 65
located thereon that may be utilized during the line lock braking
mode. For example, button 65 may be required to be held down during
at least a portion of a line lock braking mode sequence, as will be
discussed in greater detail below.
[0014] The instrument cluster 70 may include one or more displays
75 configured to provide information to the driver such as, for
example, vehicle speed or engine rotational speed. The instrument
cluster displays 75 may be utilized to provide information or
direction to the driver during the line lock braking mode. For
example, the displays 75 may provide a series of directions to the
driver to enable the vehicle to perform the controlled burnout.
[0015] The display 80 includes user interface 90, which is
configured to provide audio/visual information related to the line
lock braking system and mode to the driver. For example, the user
interface 90 may be a touch-screen configured to display one or
more soft keys 95 programmed to perform a specific function when
selected. In one example implementation, soft key 95 may be
selected by the driver to request the line lock braking mode. Once
selected, the user interface 90 can display various information
related to the line lock braking mode. For example, user interface
90 may display whether one or more vehicle conditions are satisfied
that will enable activation of the line lock braking mode. If the
conditions are not satisfied, the user interface 90 may display
information regarding the unsatisfied condition, and may
subsequently deactivate the line lock braking mode or otherwise
prevent initiation of the controlled burnout.
[0016] Additionally, user interface 90 may provide audio
communications to the driver in place of or in addition to visual
displays. Moreover, the user interface 90 may also receive audio
commands from the driver. However, the driver control system 50 is
not limited solely to the function described herein and may be
utilized in various other ways to control the line lock braking
system and associated controlled burnout.
[0017] FIG. 3 illustrates a vehicle control system 100 according to
one exemplary implementation. The vehicle control system 100 may be
in signal communication with the driver control system 50 and may
be utilized as the line lock braking system for operating vehicle
10 in the line lock braking mode. As shown, the vehicle control
system 100 generally includes a controller or brake module
integrated control unit (ICU) 110 having a brake hydraulic control
unit (HCU) 115 and a brake electronic control unit (ECU) 120. It
will be appreciated that the brake controller or module can be
implemented in various other forms. As used herein, the term
controller, module, or control unit 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.
[0018] The brake HCU 115 is coupled to a plurality of braking
devices 125 each located at one of the vehicle wheels 20, 30. The
brake HCU 115 is configured to selectively direct hydraulic fluid
to the braking devices 125 to apply hydraulic braking pressure
against that wheel 20, 30. As such, during the line lock braking
mode, the brake HCU 115 can selectively apply hydraulic braking
pressure against front wheels 20 while releasing hydraulic braking
pressure against the rear wheels 30. The braking devices 125 may be
any suitable type of brake such as for example, disc brakes, drum
brakes, electronic brakes, or the like.
[0019] The brake ECU 120 is in signal communication with a
plurality of wheel speed sensors 130 each located at one of the
vehicle wheels 20, 30. The brake ECU 120 is configured to receive a
signal from the wheel speed sensors 130 indicating a number of
rotations performed by the vehicle wheels 20, 30. For example, the
signal may indicate tone wheel pulses, which can be utilized to
calculate the number of rotations of wheels 20, 30. The number of
rotations of rear wheels 30 may then be used to determine when the
controlled burnout is stopped. For example, the line lock braking
mode may be deactivated when the number of rotations of the rear
wheels 30 exceeds a predetermined number. In one example, the
predetermined number of rotations is between approximately 300 and
approximately 500. in another example, the predetermined number of
rotations is between 300 and 500. In yet another example, the
predetermined number of rotations is approximately 400. In yet
another example, the predetermined number of rotations is 400.
[0020] However, it will be appreciated that the number of wheel
rotations may be adjusted based on various factors such as, for
example, weather conditions, ambient temperature, track surface
temperature, and tire type. For example, network controller 150 may
request various inputs/conditions and vary the wheel rotation
threshold accordingly such as by using an algorithm for such
purposes.
[0021] Driver input devices 140 are in signal communication with
the brake ECU 120 either directly or through a network controller
150. The driver input devices 140 are configured to provide
information and/or control the controller 150, which controls the
brake ECU 120. For example, the driver input devices 140 can be
utilized to activate the line lock braking mode and/or perform
portions of the line lock braking sequence. As illustrated in the
example implementation of FIG. 2, driver input devices 140 can
include steering wheel 60, instrument cluster 70, user interface
90, an accelerator pedal 155 and associated powertrain control
module 160, and a brake pedal 165. However, the network controller
150 may be in signal communication with various other vehicle
control modules and/or sensors.
[0022] The network controller 150 is configured to control the
distribution of hydraulic fluid between the brake HCU 115 and the
individual braking devices 125 based on information received from a
vehicle system or the driver (e.g., via the driver input devices
140). As such, the network controller 150 is configured to activate
and deactivate the line lock braking mode.
[0023] FIG. 4 illustrates an example method 200 of line lock
braking a vehicle for a controlled burnout. The method 200
generally includes (I) receiving a request for a line lock braking
mode, (II) checking initial vehicle preconditions for entering the
line lock braking mode, (Ill) checking secondary vehicle conditions
for entering the line lock braking mode, (IV) activating the line
lock braking, and (V) deactivating the line lock braking after a
predetermined condition occurs such as, for example, upon a driver
releasing button 65 or when the rear wheels exceed a predetermined
number of rotations during the line lock.
[0024] In one exemplary implementation, at step 202, controller 150
receives a signal indicating a driver request for the line lock
braking mode. For example, the driver may initiate the request by
selecting soft key 95 of the user interface 90 or by providing an
audio command to the driver control system 50. At step 204,
controller 150 directs the driver to refer to the instrument
cluster 70. For example, display 80 may provide an audio or visual
indicator to the driver to refer to the instrument cluster 70.
[0025] At step 206, controller 150 confirms one or more
non-correctable or initial vehicle preconditions are satisfied.
Each of the initial vehicle preconditions must be satisfied to
enter the line lock mode. In one exemplary implementation, the
initial vehicle preconditions include one or more of the following:
(a) the internal vehicle speed is less than or equal to 10 MPH; (b)
the engine RPM is greater than 500 RPM; (c) a temperature of the
transmission is not over a predetermined temperature (e.g.,
approximately 140.degree. C.; (d) the engine is running; (e) no
current active electronic stability control (ESC) faults that
inhibit line lock are present (e.g., wheel speed sensor faults,
brake pressure sensor faults, internal module faults, yaw sensor
faults, or any other faults that affect the integrity of the
function); (f) a radiator coolant temperature is less than
approximately 250.degree. F.; (g) the odometer is greater than a
predetermined number (e.g., 500 miles); (h) a valet mode is not
active (e.g., where a drive mode is requested by the vehicle owner
to limit the functionality of the vehicle such as reduced engine
power); (i) vehicle doors are closed; (j) cruise control is not
enabled or active; and (h) launch control is not active (e.g., a
system that assists the driver in maintaining a set engine speed
prior to launch and then manages wheel slip from launch to a
predetermined speed, thereby providing a reliable and consistent
acceleration profile). However, step 206 is not limited to the
above described preconditions and may include additional initial
vehicle preconditions.
[0026] If one or more of the initial vehicle preconditions are not
satisfied, at step 208, controller 150 rejects the line lock
braking mode request. At step 210 controller 150 may provide a
message to the driver via driver control system 50 indicating that
the line lock request has been rejected. For example, display 80
may provide a message indicating that the line lock is unavailable
and the reason(s) that the line lock is unavailable (i.e., which
initial preconditions were not satisfied). For example, display 80
may indicate that the vehicle speed is too high, the engine speed
is too low, the coolant temperature is too high, a vehicle door is
open, etc.
[0027] If all of the initial vehicle preconditions are met, control
proceeds to step 212 where controller 150 confirms one or more
correctable or secondary vehicle preconditions are satisfied. In
one exemplary implementation, the secondary vehicle preconditions
include one or more of the following: (i) the vehicle speed is zero
MPH; (ii) the brake pedal pressure is greater than a predetermined
pressure (e.g., greater than 50 bar); (iii) in an automatic
transmission, the transmission is in a forward gear (e.g., drive);
(iv) in a manual transmission, the transmission is not in reverse
(R); and (v) the vehicle traction control or stability setting must
be "sport" or "full-off". However, step 212 is not limited to the
above described preconditions and may include additional secondary
vehicle preconditions.
[0028] Each of the secondary vehicle preconditions must be
satisfied to enter the line lock mode. However, unlike the initial
vehicle preconditions, if one or more of the secondary
preconditions is not satisfied, at step 214, the controller 150 may
invite the driver to remedy the unsatisfied secondary
preconditions. For example, if one of the secondary preconditions
is not satisfied, controller 150 may display a tutorial on the
instrument cluster 70 or display 80 that provides directions or
assistance to the driver to remedy the unsatisfied condition.
Moreover, controller 150 may only display one active correctable
secondary precondition at a time until that secondary precondition
is corrected.
[0029] In one exemplary implementation, if secondary precondition
(i) is not satisfied, instrument cluster 70 displays a message
indicating that the vehicle speed must be zero MPH. If secondary
precondition (ii) is not satisfied, instrument cluster 70 displays
a message directing the driver to apply pressure to the brake
pedal. If secondary precondition (iii) is not satisfied, instrument
cluster 70 displays a message indicating that the vehicle must be
in a forward gear. If secondary precondition (v) is not satisfied,
instrument cluster 70 displays a message indicating that the
stability setting must be "sport" or "full-off".
[0030] If all of the secondary vehicle preconditions are met,
whether initially or through the tutorial of step 214, control then
proceeds to step 216. However, if at step 218, an initial
precondition occurs during or immediately after tutorial steps 214,
control proceeds to step 220 where the line lock braking mode is
canceled. If a secondary precondition occurs or is re-enabled at
step 222, control returns to the tutorial step 214 to attempt to
remedy the precondition.
[0031] At step 216, once all of the secondary preconditions are
satisfied, controller 150 directs the driver to perform an
operation to activate the line lock braking. For example,
controller 150 may display a message on instrument cluster 70
directing the driver to press and hold button 65 on the steering
wheel 60. If the operation is performed correctly, at step 224,
controller 150 subsequently transitions the vehicle to the line
lock braking condition by releasing brake pressure from the rear
wheels 30 and maintaining brake pressure at the front wheels 20. In
other words, the braking pressure is maintained or locked in the
braking system lines and components associated with the front
wheels 20 in an absence of use of brake pedal 165.
[0032] At step 226, controller 150 directs the driver to release
the brake pedal 165 and apply the throttle (i.e., press the
accelerator pedal 155) while the driver continues to hold button
65. At this point, the rear wheels 30 should begin to rotate while
the front wheels 20 remain stationary, thereby performing the
controlled burnout.
[0033] During the controlled burnout, at step 228, controller 150
may display a message to the driver to release or disengage the
operation performed in step 216. For example, controller 150 may
display a message on instrument cluster 70 directing the driver to
release the button 65 to begin forward movement of the vehicle.
Moreover, the controller 150 may display the predetermined number
of wheel rotations on the instrument cluster 70 and/or the user
interface 90 before and/or during the controlled burnout. The
controller 150 may also display the number of real-time wheel
revolutions throughout the controlled burnout. When the revolutions
approach the revolutions threshold, a further message may be
displayed to release the button or the line lock will be canceled.
At step 230, if button 65 is released before the predetermined
number of wheel rotations is exceeded, controller 150 releases the
hydraulic pressure at front wheels 20 and the vehicle will drive
forward if the throttle is still applied.
[0034] However, prior to release of button 65, controller 150 will
cancel the line lock braking (step 232) if any of the following
conditions occur: (1) the wheel speed sensors 130 indicate the rear
wheels 30 have rotated more than the predetermined number of
rotations (e.g., 400 revolutions) during the controlled burnout in
the line lock braking mode; (2) an initial precondition occurs; (3)
a secondary precondition occurs (except for the brake pedal
pressure greater than a predetermined pressure); (4) the brake
pedal 165 is pressed; (5) the accelerator 155 is released; (6) the
vehicle rotates beyond a predetermined angle (e.g., the vehicle
rotates or slides more than 15.degree. from a starting position);
and (7) a pressure of a rear tire 30 is less than or equal to a
predetermined minimum pressure (e.g., zero PSI). However, step 232
is not limited to the above described conditions and may include
additional time-independent line lock cancelling conditions.
[0035] If any of the above conditions occurs, control proceeds to
step 220 and the line lock braking mode is canceled. Thus, the line
lock braking system described herein provides the benefit of line
lock deactivation without relying on any time-based conditions. For
example, the predetermined number of revolutions for the rear tires
30 is dependent on the accelerator pedal 155 position and
corresponding requested engine torque. In other words, with lesser
pedal depression, there will be fewer tire revolutions per minute
and thus a longer burnout period as compared to greater pedal
depression, which requests more torque resulting in more rear tire
RPM, and thus a shorter burnout period before reaching the
predetermined wheel revolutions. In this way, the rear tires are
better protected from excessive wear and potential durability
issues. More specifically, the revolution threshold directly
correlates to wear of the tires and, in one exemplary
implementation, is further tunable based on factors that relate to
tire wear, such as road surface and tire type. As such, burnout
potential is maximized while also accounting for durability of the
rear tires 30.
[0036] Subsequently, at step 234, controller 150 transitions the
accelerator 155 to a dead pedal where accelerator pedal deflection
is ignored until the accelerator pedal 155 is completely released.
Subsequent pedal deflection may then be used to determine driver
input. In one implementation, dead pedal only occurs when the
predetermined number of wheel revolutions is exceeded. The vehicle
10 then returns to normal operating behavior once the line lock
braking mode is deactivated.
[0037] Described herein are system and methods for providing a
controlled burnout for a vehicle. A driver control system is in
communication with a network controller, which is configured to
control a hydraulic brake system. Upon satisfying initial and
secondary vehicle preconditions, the controller activates a line
lock braking mode where brake pressure is released from the rear
wheels and the brake pressure is maintained at the front wheels,
thereby enabling the controlled burnout. The line lock braking mode
is deactivated when the rear wheels have spun a predetermined
number or times, or if the mode is aborted either manually by the
driver or automatically by the vehicle/system. The vehicle then
returns to normal operating behavior after the line lock braking
mode is deactivated. Accordingly, there are no time-out or time
based cancellation features or thresholds at any stage or state of
the line lock braking feature. Instead, the described system
monitors time-independent conditions and deactivates the line lock
braking feature based off the number of times the vehicle's rear
wheels have rotated.
[0038] It should be understood that the mixing and matching of
features, elements and/or functions between various examples may be
expressly contemplated herein so that one skilled in the art would
appreciate from the present teachings that features, elements
and/or functions of one example may be incorporated into another
example as appropriate, unless described otherwise above.
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