U.S. patent application number 12/691585 was filed with the patent office on 2011-07-21 for vehicle line-locking braking system and method.
This patent application is currently assigned to Ford Global Technologies LLC. Invention is credited to Daniel Joseph Dunn, Michael V. Leese, Scott Mlynarczyk.
Application Number | 20110175438 12/691585 |
Document ID | / |
Family ID | 43598661 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110175438 |
Kind Code |
A1 |
Mlynarczyk; Scott ; et
al. |
July 21, 2011 |
Vehicle Line-Locking Braking System and Method
Abstract
The present disclosure relates to a computer-implemented method
of line-locking a hydraulic vehicle braking system. The method
includes performing a preliminary system check and controlling the
distribution of fluid between a hydraulic module and two sets of
vehicle brakes when the preliminary check is satisfied.
Inventors: |
Mlynarczyk; Scott; (South
Lyon, MI) ; Dunn; Daniel Joseph; (Canton, MI)
; Leese; Michael V.; (Troy, MI) |
Assignee: |
Ford Global Technologies
LLC
|
Family ID: |
43598661 |
Appl. No.: |
12/691585 |
Filed: |
January 21, 2010 |
Current U.S.
Class: |
303/20 ;
701/70 |
Current CPC
Class: |
B60T 13/662 20130101;
B60T 8/26 20130101; B60T 13/686 20130101; B60T 8/175 20130101; B60T
2240/02 20130101; B60T 2270/89 20130101; B60T 8/32 20130101; B60T
8/1766 20130101 |
Class at
Publication: |
303/20 ;
701/70 |
International
Class: |
B60T 13/68 20060101
B60T013/68; G06F 19/00 20060101 G06F019/00 |
Claims
1. A computer-implemented method of line-locking a hydraulic
vehicle braking system, comprising: receiving an electric signal
through a user interface to a control module; performing a
preliminary system check; and controlling the distribution of fluid
between a hydraulic module and two sets of vehicle brakes when the
preliminary check is satisfied.
2. The method of claim 1, wherein performing a preliminary system
check includes assessing the vehicle speed.
3. The method of claim 1, wherein performing a preliminary system
check includes assessing whether a predetermined time limit has
been exceeded.
4. The method of claim 1, wherein performing a preliminary system
check includes assessing a steering wheel position.
5. The method of claim 1, wherein performing a preliminary system
check includes assessing whether a vehicle traction control system
is inactive.
6. The method of claim 1, wherein performing a preliminary system
check includes assessing whether a predetermined user command is
received.
7. The method of claim 1, wherein performing a preliminary system
check includes assessing whether a vehicle service brake is
applied.
8. The method of claim 1, wherein the controlling the distribution
of fluid includes disconnecting the hydraulic module from the first
and/or second set of hydraulic brakes.
9. A vehicle braking system, comprising: a first hydraulic brake
module; a second hydraulic brake module; a hydraulic module
configured to provide fluid to the first and second brake modules;
a valve system between the hydraulic module and the first and
second brake modules, configured to disconnect the hydraulic module
from the first and/or second set of hydraulic brake modules; and an
electric control module configured to control the valve system.
10. The braking system of claim 9, wherein the electric control
module is linked to a user interface, configured to receive a
signal from the user interface; and wherein the electric control
module comprises system check logic configured to assess whether a
predetermined user command is entered into the user interface.
11. The braking system of claim 9, wherein the predetermined user
command is a reset command, escape command or break in ignition key
cycle.
12. The braking system of claim 9, wherein the electric control
module comprises system check logic configured to assess the
vehicle speed; and wherein the control module is configured to at
least partially turn the valve system off when the vehicle speed
exceeds a predetermined amount.
13. The braking system of claim 9, wherein the electric control
module comprises system check logic configured to assess whether a
predetermined time limit has been exceeded; and wherein the control
module is configured to at least partially turn the valve system
off when the predetermined time limit has been exceeded.
14. The braking system of claim 9, wherein the electric control
module comprises system check logic configured to assess a steering
wheel position; and wherein the control module is configured to at
least partially turn the valve system off when the steering wheel
position is less than or greater than a predetermined angular
range.
15. The braking system of claim 9, wherein the electric control
module comprises system check logic configured to assess whether a
vehicle traction control system is inactive; and wherein the
control module is configured to at least partially turn the valve
system off when the traction control system is active.
16. The braking system of claim 9, wherein the electric control
module comprises system check logic configured to assess whether a
vehicle service brake is applied; and wherein the control module is
configured to at least partially turn the valve system off when the
vehicle service brake is applied.
17. A vehicle configured to line-lock, the vehicle comprising: a
user interface; an electric control module linked to the user
interface and configured to receive a signal from the user
interface for activation of a line-locking mode of operation; a
first hydraulic brake; a second hydraulic brake; a hydraulic module
configured to provide fluid to the first and second brakes; and a
valve system between the hydraulic module and the first and second
brakes, configured to disconnect the hydraulic module from the
first and/or second set of hydraulic brakes; wherein the control
module is configured to control the valve system.
18. The vehicle of claim 17, wherein the user interface is
incorporated into an instrument panel in the vehicle interior.
19. The vehicle of claim 18, wherein the user interface includes a
cancel command key configured to re-start the control module.
20. The vehicle of claim 18, wherein the user interface includes a
message center configured to deliver system information to a
vehicle user.
21. The vehicle of claim 18, wherein the electric control module
comprises system check logic configured to assess at least one
vehicle condition and control the valve system according to the
vehicle condition.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to methods of line-locking
hydraulic braking systems and braking systems for accomplishing the
same.
BACKGROUND
[0002] Conventional vehicle braking systems include hydraulic and
electric systems. Each system provides different performance
characteristics. Generally speaking, hydraulic systems are more
widely implemented and are less complex, less expensive braking
systems. There are contemporary hydraulic systems that are
supplemented with electronic components to provide anti-lock
braking and traction control.
[0003] Some vehicles, e.g., "muscle cars," manipulate a vehicle's
braking system to improve tire traction at vehicle launch. To
ensure maximum tire grip at take-off, a driver can conduct a
"burn-out" in a water box to heat up the rear tires just prior to
launch. With many conventional vehicles, in order to conduct a
controlled burnout, a driver needs to manipulate the service brake
system to allow the rear wheels to spin freely while the front
brakes are applied. In some cases, the burn-out is achieved by the
driver manipulating the throttle, brake and clutch. This is not a
user-friendly delivery system, however, as it requires the driver
to synchronize inputting various commands into the vehicle
simultaneously. Moreover, if the vehicle is not in the best
condition for burn-out, e.g., the wheels are slightly turned, it
can be difficult for the driver to detect this.
[0004] Alternatively, a vehicle owner can install an aftermarket
system that will allow the driver to keep the front brakes applied
while the rear brakes are released; after the driver releases the
brake pedal a much more controlled burn-out can be accomplished.
Such aftermarket systems are inferior to a system incorporated with
original vehicle equipment for various reasons. For example,
aftermarket systems can have reliability issues, are usually purely
mechanical systems having no electric or automated controls which
can also be less user-friendly, they are not repeatable and they do
not perform preferred preliminary system checks that can increase
the performance of the braking system before, during and/or after
burn-out.
[0005] There are completely electric braking systems that can be
incorporated into the vehicle which control the distribution of
power between the front and rear braking systems. For example, U.S.
Patent Application No. 2008/0015761 titled "Electric Braking Device
for Vehicles" discloses a purely electric braking system that
includes an on-board computer and control module which controls the
power supply to the braking modules. Since this system utilizes
electric brakes the system is more complex and more expensive than
systems having hydraulic brakes. Moreover, the control logic
disclosed in the '761 Application is not tailored to a line-locking
function but is tailored toward mitigating detected degradations in
the operating modes of the brakes to reduce the overall power
consumption of a vehicle. The disclosed braking device would not
accommodate a vehicle line-locking braking system.
[0006] Therefore, it is desirable to have a method of line-locking
a hydraulic vehicle braking system and a braking system for
accomplishing the same that is more user-friendly. It is further
desirable to have a system that performs preliminary system checks
to improve vehicle performance before, during and/or after
burn-out. A feature is needed that will utilize the original
vehicle equipment to provide a burn-out feature that is controlled
and repeatable for the driver without the need of adding any
additional content.
SUMMARY
[0007] The present invention may address one or more of the
above-mentioned issues. Other features and/or advantages may become
apparent from the description which follows.
[0008] Certain embodiments of the present invention include a
computer-implemented method of line-locking a hydraulic vehicle
braking system. The method includes the steps of receiving an
electric signal through a user interface to a control module;
performing a preliminary system check; and controlling the
distribution of fluid between a hydraulic module and two sets of
vehicle brakes when the preliminary check is satisfied.
[0009] Another exemplary embodiment of the present invention
include a vehicle braking system, having: a first hydraulic brake
module; a second hydraulic brake module; a hydraulic module
configured to provide fluid to the first and second brake modules;
a valve system between the hydraulic module and the first and
second brake modules, configured to disconnect the hydraulic module
from the first and/or second set of hydraulic brake modules; and an
electric control module configured to control the valve system.
[0010] Another exemplary embodiment of the present invention
involves a vehicle configured to line-lock. The vehicle includes: a
user interface; an electric control module linked to the user
interface and configured to receive a signal from the user
interface for activation of a line-locking mode of operation; a
first hydraulic brake; a second hydraulic brake; a hydraulic module
configured to provide fluid to the first and second brakes; and a
valve system between the hydraulic module and the first and second
brakes, configured to disconnect the hydraulic module from the
first and/or second set of hydraulic brakes. The control module is
configured to control the valve system.
[0011] The present teachings provide a method that will allow the
driver to apply the vehicle brake system in such a manner to allow
a controlled burn-out utilizing the vehicles electronically
controlled hydraulic brake system.
[0012] One advantage of the disclosed burn-out or line-locking
feature is that it utilizes standard equipment already found on
vehicles. There is no need for an owner to purchase an aftermarket
add-on system.
[0013] The disclosed line-locking feature utilizes failsafe
criteria so that the system can only be activated in a controlled
manner. Moreover, the disclosed features constantly monitor key
vehicle parameters and conditions once activated to ensure the
driver maintains control and mechanical/electronic malfunctions are
accounted for.
[0014] Another advantage of the disclosed teachings is that they
enable original equipment manufactures to coupe additional revenue
by providing a feature that customers currently purchase from
aftermarket suppliers. Customers also enjoy additional benefits as
a factory warranty can apply to the line-locking braking
features.
[0015] Yet another advantage of the disclosed braking systems is
that they can be incorporated into the vehicle providing a user or
driver interface. The interface is integrated into the vehicle
versus having to make modifications to the vehicle for aftermarket
systems.
[0016] An additional advantage to the disclosed line locking system
is that it is based on electronic control which provides very
repeatable and controlled burn-outs versus an add-on system that
can have significant variability.
[0017] In the following description, certain aspects and
embodiments will become evident. It should be understood that the
invention, in its broadest sense, could be practiced without having
one or more features of these aspects and embodiments. It should be
understood that these aspects and embodiments are merely exemplary
and explanatory and are not restrictive of the invention.
[0018] The invention will be explained in greater detail below by
way of example with reference to the figures, in which the same
references numbers are used in the figures for identical or
essentially identical elements. 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. In the figures:
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a rear view of a vehicle with a braking system
according to an exemplary embodiment of the present invention.
[0020] FIG. 2 is a perspective view of a center mounted console
having a user message center compatible with the vehicle shown in
FIG. 1.
[0021] FIG. 3 is schematic illustration of a vehicle braking system
compatible with the vehicle shown in FIG. 1.
[0022] FIG. 4 is a schematic illustration of a control module
compatible with the vehicle braking system of FIG. 3.
[0023] FIG. 5 illustrates an algorithm for controlling a vehicle
braking system and user message center.
[0024] Although the following detailed description makes reference
to illustrative embodiments, many alternatives, modifications, and
variations thereof will be apparent to those skilled in the art.
Accordingly, it is intended that the claimed subject matter be
viewed broadly.
DETAILED DESCRIPTION
[0025] Referring to the drawings, FIGS. 1-5, wherein like
characters represent the same or corresponding parts throughout the
several views there are shown exemplary vehicle line locking
braking systems and methods pertaining to the use of the same. The
disclosed braking systems can be used in various types of vehicles
including for example small/large cars, coupes, sedans,
convertibles, trucks, vans, minivans and SUVs. In some embodiments,
the braking systems include hydraulic brake modules that are
governed by an electric control module.
[0026] The present teachings provide a method that will allow the
driver to apply the vehicle's brake system in a manner to allow a
controlled burn-out, utilizing the vehicles electronically
controlled hydraulic brake system. In the illustrated exemplary
embodiments, a vehicle electronic brake system includes an
electronic module which is attached to a hydraulic brake valve
block. Each individual wheel braking circuit is controlled via the
electronic module and manipulated by the hydraulic valve block. The
electronic module has the capability to provide brake pressure,
remove brake pressure and hold brake pressure to individual
wheels.
[0027] Referring now to FIG. 1, there is shown therein a rear view
of a vehicle 10 configured with a braking system according to an
exemplary embodiment of the present invention. The vehicle 10 has a
vehicle cabin 20 where the operator or driver is seated. The
vehicle cabin 20 includes controls that the driver can utilize to
enable the line-locking feature for the braking system. The shown
vehicle 10 is capable of achieving an expedited launch with the use
of an exemplary braking system without the addition of aftermarket
vehicle systems.
[0028] The shown vehicle 10 has a braking system that includes
hydraulic braking modules that are linked to a valve system (as
discussed with respect to FIGS. 3-4). A valve system is controlled
by an electric control module. The driver controls activation and
de-activation of each braking module via an electronic control
module (e.g., 330 as discussed with respect to FIG. 3). In the
shown embodiments, the electric control module includes system
check logic that can be indicative of various vehicle conditions.
To enable the line-locking feature for the braking system, the
driver first selects this mode of control via a vehicle selection
menu in the message center (e.g., 130 as shown in and discussed
with respect to FIG. 2). Once selected, the driver will apply the
service brakes to a pre-defined pressure. When the brake pressure
is achieved, the brake electronic module will isolate the vehicle's
front brake module(s) or circuit(s) from the driver via the
hydraulic brake control valves or valve systems and the pressure
will be locked and communicated to the driver. At that point the
driver can remove pressure from the brake pedal and the front
brakes will remain applied. The driver can then apply throttle and
initiate a burn-out or burning rubber on the rear wheels 30,
creating tire smoke 40 as shown in FIG. 1.
[0029] The vehicle includes a message center 50 with a user
interface 60 for the driver, as shown in FIG. 2. The user interface
60 can be incorporated into the vehicle instrument panel 70 or
instrument cluster. The interface 60 can be included in a center
console (e.g., 80) or other locations in the vehicle interior as
well. An electric control module is linked to the user interface 60
and configured to receive a signal from the user interface for
activation or deactivation of a line-locking mode of operation.
Control module can be hardwired or in wireless communication with
the user interface 60.
[0030] User interface 60, shown in FIG. 2, is configured to provide
a user with audio and/or visual indicators of braking system and
vehicle conditions. The electric control module comprises system
check logic configured to assess at least one vehicle condition and
control the valve system according to the vehicle condition. The
shown interface 60 includes a touch screen with "soft keys" 90 and
100 to receive user input. The user interface 60 can also receive
driver inputs with respect to control of the braking system. For
example, in the shown embodiment, the user interface is configured
with a start command key 90 that instructs the control module to
start from the beginning of the operating sequence for the
line-locking feature of the braking system. The user interface also
includes a cancel command key 100 configured to cancel the line
lock selection. Where the driver has initiated the starting
sequence of the line-locking feature, the sequence can be
interrupted. The user interface also includes a message center
configured to deliver system information to a vehicle user.
[0031] User interface 60 is configured to receive and output audio
commands as well. User interface 60 includes a microphone linked to
the control module. Control module is configured with voice
recognition software. User interface 60 is configured to, for
example, restart the operating sequence for line locking upon
receiving a "reset" audio command. The user interface 60 is also
configured to abandon the line-locking braking sequence by
receiving the escape command. The "escape" audio command interrupts
the operating sequence of the control module when the braking
system is operating in line-locking mode.
[0032] In the embodiment illustrated in FIG. 2, the user interface
60 includes a message center 130 configured to audibly deliver
system information to a vehicle user. For example, where the system
has abandoned the line-locking operating sequence the user
interface 60 can send a text or audible message of "system abort"
to the driver. Any number of messages or commands can be programmed
into the control module for execution.
[0033] Referring now to FIG. 3, there is shown therein a vehicle
braking system 200 according to an exemplary embodiment of the
present invention. The braking system 200 is designed for use with
a four-wheel vehicle, for example, as shown in FIG. 1. The braking
system in FIG. 3 is attached to a vehicle chassis having four
wheels 210. At each wheel a braking module 220, 230, 240 and 250 is
dedicated to selectively apply braking pressure against the wheel.
Braking modules 220, 230, 240 and 250 are hydraulic braking
modules. Braking modules 220, 230, 240 and 250 can be, for example,
disc brakes, drum brakes or electric brakes. Hydraulic fluid is
supplied to the braking modules 220, 230, 240 and 250 via hydraulic
modules (or cylinders) 260, 270. Hydraulic module 260 provides
fluid to braking modules 220 and 230. Hydraulic module 270 supplies
fluid to braking modules 240 and 250.
[0034] A valve system 280 is positioned between the hydraulic
modules 260, 270 and the brake modules 220, 230 and 240, 250
respectively as shown in FIG. 3. The illustrated valve system 280
includes four valves 290, 300, 310 and 320 that control the
distribution of fluid from the hydraulic modules to each brake
modules. Valve system 280 is configured to selectively, at least
partially disconnect the hydraulic modules from the brake modules.
In the shown embodiment, valve 290 controls the distribution of
fluid between hydraulic module 260 and brake module 220. Valve 300
controls the distribution of fluid between hydraulic module 260 and
brake module 230. Valve 310 controls the distribution of fluid
between hydraulic module 270 and brake module 240. Valve 320
controls the distribution of fluid between hydraulic module 270 and
brake module 250. In this way brakes can be selectively turned on
and off on any individual wheel or set of wheels.
[0035] An electric control module 330 is also included in the
braking system 200 shown in FIG. 3. Control module 330 is
configured to control the valve system 280. Control module 330 is
linked to valves 290, 300, 310 and 320. Control module 330 can be
hard-wired or wirelessly connected to the valves. In one
embodiment, valves 290, 300, 310 and 320 include solenoids and are
actuated upon receiving an electric control signal from the control
module 330. Control module 330 includes a microprocessor (e.g., 350
as shown in FIG. 4) configured to execute predetermined commands
and receive commands from a user interface.
[0036] The electric control module 330 is linked to a user
interface 60, for example, as shown in FIG. 2. Control module 330
is configured to receive signals from the user interface 60.
Signals can be indicators of vehicle conditions or commands for the
control module 330. The electric control module 330 includes system
check logic configured to assess whether a predetermined user
command is entered into the user interface. Control module 330 is
responsive to various user commands, such as, e.g., a reset
command, escape command or a break in the ignition key cycle.
[0037] Referring now to FIG. 4, there is shown therein the control
module 330 with other braking system components. Control module 330
is configured to at least control a valve system 280 that governs
the distribution of fluid between a first set of brakes 340 and a
second set of brakes 350. Control module 330 is linked to various
vehicle systems through sensors configured to take measurements of
vehicle performance characteristics and user inputs. In the shown
embodiment, control module 330 is linked to a user interface 360.
User interface 360 enables the vehicle driver to send information
to the control module 330 and enable the control module to relay
information to the driver.
[0038] As shown in FIG. 4, the electric control module 330 includes
system check logic 370 configured to assess vehicle speed. Control
module 330 is linked to the vehicle odometer 380. The control
module 330 is configured to at least partially turn the valve
system off when the vehicle speed exceeds a predetermined
amount.
[0039] The system check logic 370 is configured to assess whether a
predetermined time limit has been exceeded. A timer 390 is linked
to the control module 330. Initiating the operating sequence for
the line-locking braking feature starts the timer 390. The control
module 330 is configured to at least partially turn the valve
system 280 off when the predetermined time limit has been exceeded.
In one embodiment, the timer 390 is set to 30 seconds from
activation of the line locking system. In another exemplary
embodiment, the timer 390 is set to 180 seconds from activation of
the line locking system.
[0040] The system check logic 370 is configured to assess a
steering wheel position. The steering wheel column includes a
position sensor 400 in communication with control module 330. In
one embodiment, the control module 330 is configured to at least
partially turn the valve system 280 off when the steering wheel
position is less than or greater than a predetermined angular
range. For example, if the steering wheel is turned more than 3
degrees from a longitudinal axis of the vehicle the control module
can abort the line-locking operating sequence and deactivate the
valve on the rear brakes 350.
[0041] The system check logic 370, as shown in FIG. 4, is
configured to assess whether a vehicle traction control system 410
is inactive. The vehicle traction control system 410 is configured
to control the vehicle's antilock braking system and other
all-weather control features. In one embodiment, the traction
control system 410 is configured to reduce tire slip. The control
module 330 is configured to at least partially turn the valve
system 280 off when the traction control system 410 is active. The
electronic module 330 combined with the hydraulic valve system 280
is designed to perform vehicle stability control functions such as
traction control and yaw control.
[0042] Any number of sensors can be linked to the control module
330 for use with the line locking braking system 200. "X_Sensor"
420 is a sensor representing any number of exemplary sensors that
can be included in the system 200. For example, in the shown
embodiment the vehicle braking system 200 includes system check
logic 370 configured to assess whether a vehicle service brake is
applied. A sensor, such as X_Sensor 420, is included in the
transmission to determine if the service brake or park pawl is
applied. The control module 330 is configured to at least partially
turn the valve system 280 off when the vehicle service brake is
applied. Other sensors, such as brake fluid viscosity sensors,
wheel speed sensors, brake fluid level monitors and other devices
can be utilized with the line locking braking system 200.
[0043] Though the links shown between system components are
described in terms of hardwired connections, any one of the
components can be wirelessly linked to the control module.
Bluetooth technology, configured to enable short-range
communication between electronic devices, is utilized to enable the
components to communicate with the control module wirelessly. Other
wireless standards or technologies can be used with the braking
system such as infrared systems, RF systems, IEEE standard 802.11
and other communications platforms.
[0044] Referring now to FIG. 5, there is illustrated therein an
algorithm 500 for controlling a vehicle braking system and user
message center. The illustrated algorithm 500 can be executed by a
processor circuit incorporated into a control module, e.g., system
check logic 370 as shown in FIG. 4. System commands can be inputted
into the control module via a user interface, e.g., 60 as shown in
FIG. 2. User interface 60 sends electric signals to a control
module or computer to execute the steps of the algorithm 500. The
control module implements the line locking algorithm 500 by
controlling the distribution of fluid between a hydraulic module
and two sets of vehicle brakes or brake modules.
[0045] At step 510, as shown in FIG. 5, the line-locking mode of
operation is initiated. Driver enters information indicative of a
desire to utilize the vehicle line lock feature. At step 520 the
control module checks the vehicle speed. If the speed is not equal
to a predetermined amount valves to the rear brake modules are
turned off and the braking system is unable to operate the line
locking feature (step 530). In this embodiment, the system is
disabled if the vehicle speed is not equal to zero. The driver is
unable to select the line lock from the message center. In the
illustrated algorithm, if the speed is equal to zero the driver can
select line lock from the vehicle message center (step 540). At
this point in the operating sequence the message text center can
either display that the line lock is "on" or "off" as shown at step
550.
[0046] At step 560 as shown in FIG. 5, the vehicle line lock
feature is enabled but not fully active. The message center
displays a message to the driver indicating "line lock available"
(step 570). Thereafter, the system enters into two preliminary
system checks. In each series of system checks the algorithm
monitors the time elapsed since activation of the line locking
feature. At steps 580 and 590 the system checks a timer to
determine if a predetermined time maximum has been exceeded. If the
time limit is exceeded valves to the rear braking modules are
turned off and the line lock feature is cancelled (step 600). A
signal is sent to the message center indicating that the line lock
is off 610.
[0047] Algorithm also checks the vehicle speed at steps 620 and
630. At step 630 the control module checks the vehicle odometer. If
the vehicle speed is in excess of a predetermined amount the line
lock feature is cancelled and the system proceeds to step 600. A
signal is sent to the message center indicating that the line lock
is off 610. If the vehicle speed is zero the operating sequence
continues to another system check. At step 640 the control module
checks to see whether a predetermined user command is received; the
module checks to see if the ignition key has been cycled. If the
ignition has been cycled valves to the rear braking modules are
turned off and the line lock feature is cancelled 600. A signal is
sent to the message center indicating that the line lock is off
610.
[0048] At step 650, as shown in FIG. 5, the system checks if the
service brakes are applied. If the service brake is applied valves
to the rear braking modules are turned off and the line locking
operating system is cancelled 600. At step 660 the system checks
the steering wheel to ensure that it is properly inline. If the
steering wheel is posited less than or greater than a predetermined
angular range valves to the rear braking modules are turned off and
the line lock feature is cancelled 600. At step 670 the system
checks to see if the vehicle traction control system is inactive.
If the traction control system is active valves to the rear braking
modules are turned off and the line lock feature is cancelled
600.
[0049] To activate the line locking feature the driver presses the
escape switch as shown at step 680 in FIG. 5. The hydraulic module
is disconnected from the rear set of brake modules. Pressing escape
releases the valve on the rear braking modules. The rear wheels are
able to move freely while the front brakes stay active. Burn out
can be initiated and line lock is active (step 690). Control module
sends a notification to the message center indicating that the line
lock is engaged (step 700). If the driver hits the escape key a
second time, as shown in step 710, the system exits the line
locking operating mode. The line lock feature is cancelled 600. A
signal is sent to the message center indicating that the line lock
is off 610.
[0050] Control module can be configured to include a greater or
fewer number of preliminary system checks before activating the
line locking feature. The exemplary preliminary system checks are
designed to improve the performance of the vehicle before, during
or after launch. Other preliminary system checks can be programmed
into the control module or added to the braking system and be
within the scope of the present invention.
[0051] It will be apparent to those skilled in the art that various
modifications and variations can be made to the methodologies of
the present invention without departing from the scope its
teachings. Other embodiments of the invention will be apparent to
those skilled in the art from consideration of the specification
and practice of the teachings disclosed herein. It is intended that
the specification and examples be considered as exemplary only.
[0052] While the best modes for carrying out the invention have
been described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention within the scope of the
appended claims.
* * * * *