U.S. patent application number 15/229268 was filed with the patent office on 2018-02-08 for active brake retraction system with vacuum reservoir.
The applicant listed for this patent is GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to David B. Antanaitis, Kevin D. Connor, Douglas N. Reed.
Application Number | 20180037206 15/229268 |
Document ID | / |
Family ID | 60996490 |
Filed Date | 2018-02-08 |
United States Patent
Application |
20180037206 |
Kind Code |
A1 |
Antanaitis; David B. ; et
al. |
February 8, 2018 |
Active Brake Retraction System With Vacuum Reservoir
Abstract
A vehicle includes a brake system. The brake system includes a
hydraulic brake line having a line pressure. The vehicle
additionally includes a vacuum reservoir. The vacuum reservoir is
selectively fluidly coupled to the hydraulic brake line. The vacuum
reservoir is configured to, when fluidly coupled to the hydraulic
brake line, reduce the line pressure during a drive cycle.
Inventors: |
Antanaitis; David B.;
(Northville, MI) ; Connor; Kevin D.; (Armada,
MI) ; Reed; Douglas N.; (Milford, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM GLOBAL TECHNOLOGY OPERATIONS LLC |
Detroit |
MI |
US |
|
|
Family ID: |
60996490 |
Appl. No.: |
15/229268 |
Filed: |
August 5, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60T 11/26 20130101;
B60T 2201/12 20130101; F16D 2055/0029 20130101; B60T 8/4225
20130101; B60T 8/4216 20130101; B60T 8/4872 20130101; B60T 13/72
20130101; B60T 8/4881 20130101; B60T 13/565 20130101 |
International
Class: |
B60T 13/72 20060101
B60T013/72; B60T 13/565 20060101 B60T013/565 |
Claims
1. A vehicle comprising: a traction wheel; a brake system
configured to apply braking torque to the traction wheel; a
hydraulic brake line coupled to the brake system, the hydraulic
brake line having a line pressure; a vacuum reservoir configured to
selectively fluidly couple to the hydraulic brake line during a
drive cycle and to, when fluidly coupled to the hydraulic brake
line, reduce the line pressure; a vacuum source; a first valve
configured to selectively fluidly couple the vacuum source to the
vacuum reservoir; a second valve configured to selectively fluidly
couple the vacuum reservoir to the hydraulic brake line; and a
controller configured to control the first valve to selectively
fluidly couple the vacuum source to the vacuum reservoir, and to
control the second valve to selectively fluidly couple the vacuum
reservoir to the hydraulic brake line, the controller being
configured to, in response to a first operating condition, control
the first valve to fluidly couple the vacuum source to the vacuum
reservoir and to control the second valve to fluidly isolate the
vacuum reservoir from the hydraulic brake line and, in response to
a second operating condition, control the first valve to fluidly
isolate the vacuum source from the vacuum reservoir and control the
second valve to fluidly couple the vacuum reservoir to the
hydraulic brake line.
2. The vehicle of claim 1, wherein the brake system includes a
brake caliper coupled to the hydraulic brake line, a first brake
pad coupled to the caliper, and a second brake pad coupled to the
caliper, wherein in response to a reduction in line pressure, the
brake caliper retracts the first brake pad and second brake pad
away from one another.
3-5. (canceled)
6. The vehicle of claim 1, wherein the first operating condition
includes a brake application initially exceeding a first calibrated
threshold and subsequently falling below a second calibrated
threshold.
7. The vehicle of claim 1, wherein the vacuum source comprises a
vacuum pump.
8. A brake system for a vehicle, comprising: a hydraulic brake line
having a fluid retained therein, the fluid having a line pressure;
a vacuum reservoir fluidly couplable to the brake line, the vacuum
reservoir being configured to, when fluidly coupled to the
hydraulic brake line, reduce the line pressure during a drive
cycle; a vacuum source; a first valve configured to selectively
fluidly couple the vacuum source to the vacuum reservoir; a second
valve configured to selectively fluidly couple the vacuum reservoir
to the hydraulic brake line; and a controller configured to, in
response to a first operating condition, control the first valve to
fluidly couple the vacuum source to the vacuum reservoir and to
control the second valve to fluidly isolate the vacuum reservoir
from the hydraulic brake line and, in response to a second
operating condition, control the first valve to fluidly isolate the
vacuum source from the vacuum reservoir and control the second
valve to fluidly couple the vacuum reservoir to the hydraulic brake
line.
9. The brake system of claim 8, further comprising a brake caliper
coupled to the hydraulic brake line, a first brake pad coupled to
the brake caliper, and a second brake pad coupled to the brake
caliper, wherein in response to a reduction in line pressure, the
brake caliper retracts the first brake pad and second brake pad
away from one another.
10-11. (canceled)
12. The brake system of claim 8, wherein the first operating
condition includes a brake application initially exceeding a first
calibrated threshold and subsequently falling below a second
calibrated threshold.
13. The brake system of claim 8, wherein the first valve includes a
first solenoid and the second valve includes a second solenoid.
14. The brake system of claim 8, wherein the vacuum source
comprises a vacuum pump.
15. A method for controlling a brake system for a vehicle,
comprising: providing a vehicle with a hydraulic brake line having
a fluid retained therein, a vacuum reservoir, and a first valve
selectively fluidly coupling the hydraulic brake line to the vacuum
reservoir; providing the vehicle with a vacuum source and a second
valve selectively fluidly coupling the vacuum reservoir to the
vacuum source; in response to a first operating condition during a
drive cycle, controlling the first valve to fluidly couple the
vacuum reservoir to the hydraulic brake line to reduce pressure in
the hydraulic brake line and controlling the second valve to
fluidly isolate the vacuum source from the vacuum reservoir; and in
response to a second operating condition during the drive cycle,
controlling the first valve to fluidly isolate the vacuum reservoir
from the hydraulic brake line controlling the second valve to
fluidly couple the vacuum source to the vacuum reservoir.
16. (canceled)
17. The method of claim 15, wherein the first operating condition
corresponds to a brake application initially exceeding a first
calibrated threshold and subsequently falling below a second
calibrated threshold.
18. The method of claim 15, wherein the first operating condition
corresponds to vehicle speed exceeding a speed threshold and brake
application below a brake threshold.
19. The method of claim 15, wherein the first operating condition
corresponds to a vehicle cruise condition.
20. The method of claim 15, wherein the second operating condition
corresponds to an anticipated braking request.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a braking system for an
automotive vehicle, and more particularly to a system and method of
retracting brake pads from associated brake rotors.
INTRODUCTION
[0002] Conventional automotive vehicles generally make use of disk
brake systems for applying frictional braking torque to vehicle
traction wheels. Disk brake systems generally utilize, at each
wheel, a brake rotor connected to an axle hub of a rotatable axle
of the vehicle. A set of selectively movable brake pads are
connected to a non-rotating brake caliper. The brake rotor includes
a disk-shaped rotor cheek having brake pad engagement surfaces.
When braking is requested, e.g. via an operator application of a
brake pedal, the braking system causes the caliper to press the
brake pads upon respective brake pad engagement surfaces of the
rotor cheek. Frictional interaction between the rotating rotor
cheek and non-rotating brake pads causes braking of the motor
vehicle. The rate of braking varies with the pressure of the brake
pads against the respective brake pad engagement surfaces of the
rotor cheek.
[0003] Dual-circuit hydraulic braking systems for automotive
applications typically include an operator-actuated brake actuation
unit, such as a tandem master cylinder actuated by a booster-aided
brake pedal, by which to supply a first pressurized brake fluid to
each of a first pair of wheel brakes via a first or "primary"
braking circuit, and a second pressurized brake fluid to each of a
second pair of wheel brakes via a second or "secondary" braking
circuit. The use of wholly redundant braking circuits for operating
discrete pairs of wheel brakes ensures continued vehicle braking
capability, notwithstanding a degradation of performance of one of
the braking circuits.
SUMMARY
[0004] A vehicle according to the present disclosure includes a
brake system. The brake system includes a hydraulic brake line
having a line pressure. The vehicle additionally includes a vacuum
reservoir. The vacuum reservoir is selectively fluidly coupled to
the hydraulic brake line. The vacuum reservoir is configured to,
when fluidly coupled to the hydraulic brake line, reduce the line
pressure during a drive cycle.
[0005] According to various embodiments, the vehicle additionally
includes a brake caliper coupled to the hydraulic brake line, a
first brake pad coupled to the caliper, and a second brake pad
coupled to the caliper. In response to a reduction in line
pressure, the brake caliper retracts the first brake pad and second
brake pad away from one another.
[0006] According to various embodiments, the vacuum source includes
a vacuum pump.
[0007] According to various embodiments, the vehicle additionally
includes a vacuum source, a first valve configured to selectively
fluidly couple the vacuum source to the vacuum reservoir, and a
second valve configured to selectively fluidly couple the vacuum
reservoir to the hydraulic brake line. In such embodiments, a
controller may be configured to control the first valve to
selectively fluidly couple the vacuum source to the vacuum
reservoir, and to control the second valve to selectively fluidly
couple the vacuum reservoir to the hydraulic brake line. The
controller may be configured to, in response to a first operating
condition, control the first valve to fluidly couple the vacuum
source to the vacuum reservoir and to control the second valve to
fluidly isolate the vacuum reservoir from the hydraulic brake line.
The controller may also be configured to, in response to a second
operating condition, control the first valve to fluidly isolate the
vacuum source from the vacuum reservoir and control the second
valve to fluidly couple the vacuum reservoir to the hydraulic brake
line. The first operating condition may include a brake application
exceeding a first calibrated threshold and subsequently falling
below a second calibrated threshold.
[0008] A brake system for a vehicle according to the present
disclosure includes a hydraulic brake line. The line has a fluid
retained therein with a fluid pressure. The brake system
additionally includes a vacuum reservoir. The vacuum reservoir is
selectively fluidly coupled to the brake line. The vacuum reservoir
is configured to, when fluidly coupled to the hydraulic brake line,
reduce the line pressure during a drive cycle.
[0009] According to various embodiments, the brake system
additionally includes a brake caliper coupled to the hydraulic
brake line, a first brake pad coupled to the caliper, and a second
brake pad coupled to the caliper, wherein in response to a
reduction in line pressure, the brake caliper retracts the first
brake pad and second brake pad away from one another.
[0010] According to various embodiments, the vacuum source includes
a vacuum pump.
[0011] According to various embodiments, the brake system
additionally includes a vacuum source, a first valve, and a second
valve. The first valve is configured to selectively fluidly couple
the vacuum source to the vacuum reservoir, and the second valve is
configured to selectively fluidly couple the vacuum reservoir to
the hydraulic brake line. In such embodiments, a controller may be
configured to control the first valve to selectively fluidly couple
the vacuum source to the vacuum reservoir, and to control the
second valve to selectively fluidly couple the vacuum reservoir to
the hydraulic brake line. The controller may be configured to, in
response to a first operating condition, control the first valve to
fluidly couple the vacuum source to the vacuum reservoir and to
control the second valve to fluidly isolate the vacuum reservoir
from the hydraulic brake line. The controller may also be
configured to, in response to a second operating condition, control
the first valve to fluidly isolate the vacuum source from the
vacuum reservoir and control the second valve to fluidly couple the
vacuum reservoir to the hydraulic brake line. The first operating
condition may include a brake application exceeding a first
calibrated threshold and subsequently falling below a second
calibrated threshold. The first valve may include a first solenoid
and the second valve may include a second solenoid.
[0012] A method for controlling a brake system for a vehicle
includes providing a vehicle with a hydraulic brake line with a
fluid retained therein, a vacuum reservoir, and a first valve
selectively fluidly coupling the brake line to the vacuum
reservoir. In response to a first operating condition during a
drive cycle, the first valve is controlled to fluidly couple the
vacuum reservoir to the brake line to reduce pressure in the brake
line. In response to a second operating condition during the drive
cycle, the first valve is controlled to fluidly isolate the vacuum
reservoir from the brake line.
[0013] According to various embodiments, the method additionally
includes providing the vehicle with a vacuum source and a second
valve selectively fluidly coupling the vacuum reservoir to the
vacuum source. In such embodiments, in response to the first
operating condition during the drive cycle, the second valve is
controlled to fluidly isolate the vacuum source from the vacuum
reservoir. In response to the second operating condition during the
drive cycle, the second valve is controlled to fluidly couple the
vacuum source to the vacuum reservoir.
[0014] According to various embodiments, the first operating
condition corresponds to a brake application exceeding a first
calibrated threshold and subsequently falling below a second
calibrated threshold, to vehicle speed being above a threshold and
brake application being below a threshold, and/or to a vehicle
cruise condition. The second condition may correspond to an
anticipated braking request.
[0015] Embodiments according to the present disclosure provide a
number of advantages. For example, systems and methods according to
the present disclosure may ensure adequate clearance between brake
rotors and brake pads, reducing residual brake drag. This may
reduce wear and tear on brake components, and may also increase
fuel economy.
[0016] The above advantage and other advantages and features of the
present disclosure will be apparent from the following detailed
description of the preferred embodiments when taken in connection
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic illustration of an embodiment of an
automotive vehicle according to the present disclosure;
[0018] FIG. 2 is another schematic illustration of an embodiment of
an automotive vehicle according to the present disclosure; and
[0019] FIG. 3 is a flowchart representation of a method for
controlling a braking system of a vehicle according to the present
disclosure.
DETAILED DESCRIPTION
[0020] Embodiments of the present disclosure are described herein.
It is to be understood, however, that the disclosed embodiments are
merely examples and other embodiments can take various and
alternative forms. The figures are not necessarily to scale; some
features could be exaggerated or minimized to show details of
particular components. Therefore, specific structural and
functional details disclosed herein are not to be interpreted as
limiting, but merely as a representative basis for teaching one
skilled in the art to variously employ the present invention. As
those of ordinary skill in the art will understand, various
features illustrated and described with reference to any one of the
figures can be combined with features illustrated in one or more
other figures to produce embodiments that are not explicitly
illustrated or described. The combinations of features illustrated
provide representative embodiments for typical applications.
Various combinations and modifications of the features consistent
with the teachings of this disclosure, however, could be desired
for particular applications or implementations.
[0021] Referring now to FIG. 1, an embodiment of a vehicle
according to the present disclosure is illustrated in schematic
form. The vehicle 10 includes a plurality of vehicle traction
wheels 12. Each wheel 12 is provided with a brake rotor 14 arranged
to rotate with the wheel 12. At least two brake pads 16 are
disposed proximate each brake rotor 14. The brake pads 16 are
carried by pistons 17, which are in turn slidably retained by a
brake caliper 18. The caliper 18, pistons 17, and brake pads 16 do
not rotate with the wheel 12.
[0022] The pistons 17 are configured to slide relative to the
caliper 18 in an application direction, i.e. inward toward the
brake rotor 14, and in a retraction direction, i.e. outward and
away from the brake rotor 14. When braking is requested, e.g. via a
driver application of a brake pedal or a request from an automated
driving system of an autonomous vehicle, the pistons 17 move in the
application direction relative to the caliper 18, such that the
brake pads 16 apply a frictional force to the brake rotor 14 to
brake the associated wheel 12. When the braking request terminates,
the pistons move in the retraction direction relative to the
caliper 18 to provide a clearance between the brake rotor 14 and
the brake pads 16. The clearance is provided such that residual
drag between the brake pads 16 and brake rotor 14 is avoided. Such
residual drag may cause unnecessary wear on the brake rotor 14 and
brake pads 16, and may also result in a reduction in fuel
economy.
[0023] Conventionally, the retraction is caused by an elastic seal
member provided between the caliper 18 and the pistons 17. When the
pistons 17 slide in the application direction relative to the
caliper 18, the seal member is elastically deformed. The seal
member applies a return force on the piston to return the piston
and brake pad in the retraction direction when the brakes are
released.
[0024] While only one assembly of brake rotor 14, brake pads 16,
pistons 17, and caliper 18 is illustrated for simplicity, it should
be understood that each wheel 12 is similarly provided with brake
pads 16, pistons 17, and a brake rotor 14.
[0025] A first fluid circuit 20, which may be referred to as a
primary circuit, supplies fluid to two of the brake calipers 18,
and a second fluid circuit 22, which may be referred to as a
secondary circuit, supplies fluid to two additional brake calipers
18. The first circuit 20 and second circuit 22 are filled with a
fluid, e.g. a brake fluid. A pressure boost module 24 controls
distribution of the fluid in the first circuit 20 and second
circuit 22. When braking is desired, the pressure boost module 24
increases fluid pressure in the first circuit 20 and second circuit
22. According to various embodiments, the pressure boost module 24
may include an ABS module, an electric brake boost module, or other
appropriate pressure boost modules. The first circuit 20 and the
second circuit 22 are also in fluid communication with a master
cylinder 25, which is in turn in supplied with fluid by a brake
fluid reservoir 26. The master cylinder 25 is configured to convert
motion of a shaft 27 to a hydraulic pressure in the first circuit
20 and second circuit 22. The shaft 27 may be directly or
indirectly controlled by a brake pedal and/or in response to
commands from an automated driving system of an autonomous
vehicle.
[0026] A vacuum reservoir 28 is selectively coupled to the brake
fluid reservoir 26 by a first valve 30. The vacuum reservoir 28 is,
in turn, selectively coupled to a vacuum source 32 by a second
valve 34. In an exemplary embodiment, the first valve 30 and the
second valve 34 include solenoid valves. The vacuum source 32 may,
in various embodiments, include a vacuum pump, an intake manifold
of an internal combustion engine, other vacuum known vacuum
sources, or a combination thereof.
[0027] The first valve 30 and the second valve 32 are under the
control of a controller 36. The controller 36 is configured to
control the first valve 30 and the second valve 32 according to
various modes, including an engaged mode and a disengaged mode.
[0028] While illustrated as a single unit, the controller 36 and
one or more other controllers can collectively be referred to as a
"controller." The controller 36 may include a microprocessor or
central processing unit (CPU) in communication with various types
of computer readable storage devices or media. Computer readable
storage devices or media may include volatile and nonvolatile
storage in read-only memory (ROM), random-access memory (RAM), and
keep-alive memory (KAM), for example. KAM is a persistent or
non-volatile memory that may be used to store various operating
variables while the CPU is powered down. Computer-readable storage
devices or media may be implemented using any of a number of known
memory devices such as PROMs (programmable read-only memory),
EPROMs (electrically PROM), EEPROMs (electrically erasable PROM),
flash memory, or any other electric, magnetic, optical, or
combination memory devices capable of storing data, some of which
represent executable instructions, used by the controller in
controlling the engine or vehicle.
[0029] The disengaged mode is illustrated in FIG. 1. In the
disengaged mode, the first valve 30 is closed to fluidly isolate
the vacuum reservoir 28 from the brake fluid reservoir 26. With the
first valve 30 closed, the master cylinder 25 may be vented to
equalize pressure in the brake fluid reservoir 26, the first
circuit 20, and the second circuit 22 to atmospheric pressure. The
second valve 34 is open to fluidly couple the vacuum reservoir 28
to the vacuum source 32. The vacuum source 32 may thus charge the
vacuum reservoir 28 by reducing the pressure in the vacuum
reservoir 28, e.g. to a calibrated pressure level below atmospheric
pressure.
[0030] In the disengaged mode, retraction of the brake pads 16 is
driven by the elastic seal member provided between the caliper 18
and the pistons 17.
[0031] In response to at least one operating condition, the
controller 36 may control the first valve 30 and the second valve
34 according to the engaged mode, illustrated in FIG. 2. According
to various embodiments, the operating condition corresponds to a
sustained acceleration condition, cruise condition, or other
condition in which brakes are not applied and imminent braking is
not anticipated. In an exemplary embodiment, the operating
condition corresponds to a braking request terminating after the
braking requests exceeds a calibrated threshold. In another
exemplary embodiment, the operating condition corresponds to
vehicle speed being above a threshold with no brakes applied.
[0032] In the engaged mode, the second valve 34 is closed to
fluidly isolate the vacuum reservoir 28 from the vacuum source 32.
The first valve 30 is opened to fluidly couple the vacuum reservoir
28 to the brake fluid reservoir 26. The vacuum reservoir 28 may
thus reduce the pressure in the brake fluid reservoir 26.
[0033] Moreover, because the engaged mode is active when brakes are
released, the compensating ports of the master cylinder 25 are
open. Thus, pressure the first circuit 20 and the second circuit 22
is reduced below atmospheric pressure. A pressure differential may
thereby be created across the pistons 17. The pressure differential
urges the pistons 17 and brake pads 16 in the retraction direction.
This additional retraction may reduce or eliminate residual brake
drag from the brake pads 16 contacting the brake rotor 14. In some
instances, this may result in up to 1 NM reduction in drag torque
for a given caliper 18.
[0034] As the pistons 17 slide in the retraction direction, fluid
is displaced into the brake fluid reservoir 26. The total air
volume in the fluid and in the vacuum reservoir 28 is thereby
reduced. This reduces the vacuum in the system, in turn reducing
the pressure differential across the pistons 17.
[0035] The initial suction rate and rate of decay of suction may be
tuned by adjusting the internal volume of the vacuum reservoir 28.
The volume of the vacuum reservoir 28 may be selected for a given
application such that the suction produced is adequate to retract
the pistons 17 a desired distance, but low enough to avoid
retracting the pistons 17 beyond a predefined maximum retraction
distance.
[0036] In an exemplary embodiment, a brake pre-fill feature may
return the brakes to a normal operating condition prior to a
subsequent braking event.
[0037] Other embodiments having alternate configurations are
contemplated within the scope of the present disclosure. For
example, the vacuum reservoir may be integrated into the brake
fluid reservoir as a combined reservoir with a vacuum chamber and a
fluid chamber. In such an embodiment, a valve selectively couples
the vacuum chamber and the fluid chamber.
[0038] Referring now to FIG. 3, a method of controlling a brake
system according to the present disclosure is illustrated in
flowchart form. The method begins at block 40.
[0039] A vacuum retraction system is controlled in a disengaged
mode, as illustrated at block 42. In an exemplary embodiment, the
vacuum system includes a vacuum reservoir, vacuum source, first and
second valves, and a controller as illustrated in the embodiment of
FIGS. 1 and 2. In this exemplary embodiment, controlling the vacuum
retraction system in the engaged mode includes fluidly coupling the
vacuum source to the vacuum reservoir, and fluidly isolating the
vacuum reservoir from a brake fluid reservoir, as illustrated in
the embodiment of FIG. 1.
[0040] At operation 44, a determination is made of whether a first
operating condition is detected. As illustrated in block 46, the
first operating condition may correspond to a signal indicative of
no braking being anticipated. Examples of such conditions include a
vehicle cruise condition, vehicle speed exceeding a threshold with
no brakes being applied, a brake request exceeding a first
calibrated threshold and subsequently falling below a second
calibrated threshold, or any combination thereof. In various
embodiments, the braking request may be received via an operator
actuation of a brake pedal, a braking command from an automated
driving system in an autonomous vehicle, or other source as
appropriate.
[0041] If the determination of operation 44 is negative, control
returns to block 42 and the vacuum retraction system continues to
be controlled in the disengaged mode. If the determination of
operation 44 is positive, control proceeds to block 48.
[0042] At block 48, the vacuum retraction system is controlled in
the engaged mode. In an exemplary embodiment, controlling the
vacuum retraction system in the engaged mode includes fluidly
isolating the vacuum source from the vacuum reservoir, and fluidly
coupling the vacuum reservoir to the brake fluid reservoir, as
illustrated in the embodiment of FIG. 2.
[0043] In an exemplary embodiment, a calibrated delay timer is
instituted before controlling the vacuum retraction system to the
engaged mode, e.g. between the first operating condition being
detected in operation 44 and the vacuum retraction system being
controlled in the engaged mode in block 48. In the exemplary
embodiment, rapid engagement and disengagement of the vacuum
retraction system during stop-and-go traffic, for example, is
avoided.
[0044] Control then proceeds to operation 50. At operation 50, a
determination is made of whether a second operating condition is
detected. As illustrated at block 52, the second operating
condition may correspond to a signal indicating that braking is
anticipated. Examples of such conditions include an operator
release of an accelerator pedal, a sensor reading indicating the
presence of an obstacle in a path of the vehicle, or a combination
thereof.
[0045] If the determination of operation 50 is negative, control
returns to block 48 and the vacuum retraction system continues to
be controlled in the engaged mode. If the determination of
operation 50 is positive, control proceeds to block 54.
[0046] At block 54, a brake prefill feature is activated to return
the brakes to normal operating condition. Control then returns to
block 42 and the vacuum retraction system is controlled in the
disengaged mode.
[0047] The processes, methods, or algorithms disclosed herein can
be deliverable to/implemented by a processing device, controller,
or computer, which can include any existing programmable electronic
control unit or dedicated electronic control unit. Similarly, the
processes, methods, or algorithms can be stored as data and
instructions executable by a controller or computer in many forms
including, but not limited to, information permanently stored on
non-writable storage media such as ROM devices and information
alterably stored on writeable storage media such as floppy disks,
magnetic tapes, CDs, RAM devices, and other magnetic and optical
media. The processes, methods, or algorithms can also be
implemented in a software executable object. Alternatively, the
processes, methods, or algorithms can be embodied in whole or in
part using suitable hardware components, such as Application
Specific Integrated Circuits (ASICs), Field-Programmable Gate
Arrays (FPGAs), state machines, controllers or other hardware
components or devices, or a combination of hardware, software and
firmware components. Such example devices may be on-board as part
of a vehicle computing system or be located off-board and conduct
remote communication with devices on one or more vehicles.
[0048] As previously described, the features of various embodiments
can be combined to form further embodiments of the invention that
may not be explicitly described or illustrated. While various
embodiments could have been described as providing advantages or
being preferred over other embodiments or prior art implementations
with respect to one or more desired characteristics, those of
ordinary skill in the art recognize that one or more features or
characteristics can be compromised to achieve desired overall
system attributes, which depend on the specific application and
implementation. These attributes can include, but are not limited
to cost, strength, durability, life cycle cost, marketability,
appearance, packaging, size, serviceability, weight,
manufacturability, ease of assembly, etc. As such, embodiments
described as less desirable than other embodiments or prior art
implementations with respect to one or more characteristics are not
outside the scope of the disclosure and can be desirable for
particular applications.
[0049] As may be seen, systems and methods according to the present
disclosure may ensure adequate clearance between brake rotors and
brake pads, reducing residual brake drag. This may reduce wear and
tear on brake components, and may also increase fuel economy.
[0050] While exemplary embodiments are described above, it is not
intended that these embodiments describe all possible forms
encompassed by the claims. The words used in the specification are
words of description rather than limitation, and it is understood
that various changes can be made without departing from the spirit
and scope of the disclosure. As previously described, the features
of various embodiments can be combined to form further embodiments
of the invention that may not be explicitly described or
illustrated. While various embodiments could have been described as
providing advantages or being preferred over other embodiments or
prior art implementations with respect to one or more desired
characteristics, those of ordinary skill in the art recognize that
one or more features or characteristics can be compromised to
achieve desired overall system attributes, which depend on the
specific application and implementation. These attributes can
include, but are not limited to cost, strength, durability, life
cycle cost, marketability, appearance, packaging, size,
serviceability, weight, manufacturability, ease of assembly, etc.
As such, embodiments described as less desirable than other
embodiments or prior art implementations with respect to one or
more characteristics are not outside the scope of the disclosure
and can be desirable for particular applications.
* * * * *