U.S. patent application number 16/160835 was filed with the patent office on 2020-04-16 for brake variation derived controller re-set schedule.
This patent application is currently assigned to Goodrich Corporation. The applicant listed for this patent is Goodrich Corporation. Invention is credited to Tyler Arsenault.
Application Number | 20200114887 16/160835 |
Document ID | / |
Family ID | 68289836 |
Filed Date | 2020-04-16 |
United States Patent
Application |
20200114887 |
Kind Code |
A1 |
Arsenault; Tyler |
April 16, 2020 |
BRAKE VARIATION DERIVED CONTROLLER RE-SET SCHEDULE
Abstract
A method for controlling a braking operation applied to a wheel
of a wheel assembly includes receiving a command signal in
proportion to an amount of braking requested at an input device;
outputting a control signal in proportion to the command signal;
receiving a wheel speed signal indicative of a speed of the wheel;
calculating an adjustment signal in proportion to the wheel speed
signal; providing a modified control signal to a brake actuator
based on the control signal and the adjustment signal; and
continually resetting a reset schedule based on the wheel speed
signal.
Inventors: |
Arsenault; Tyler; (Dayton,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Goodrich Corporation |
Charlotte |
NC |
US |
|
|
Assignee: |
Goodrich Corporation
Charlotte
NC
|
Family ID: |
68289836 |
Appl. No.: |
16/160835 |
Filed: |
October 15, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60T 2270/10 20130101;
F16D 55/36 20130101; B60T 8/1703 20130101; B60T 8/58 20130101; B64C
25/44 20130101; B60T 8/17616 20130101; B60T 8/171 20130101; B60T
2240/00 20130101; G05B 19/416 20130101; B60T 8/172 20130101; G05B
2219/42047 20130101; B60T 8/325 20130101; B60T 2210/12
20130101 |
International
Class: |
B60T 8/17 20060101
B60T008/17; B60T 8/171 20060101 B60T008/171; B60T 8/172 20060101
B60T008/172; B60T 8/1761 20060101 B60T008/1761; B60T 8/58 20060101
B60T008/58; B60T 8/32 20060101 B60T008/32; G05B 19/416 20060101
G05B019/416 |
Claims
1. A brake control system for controlling a braking operation
applied to a wheel of a wheel assembly, comprising: a brake control
unit configured to output a control signal to a Proportional
Integral Derivative (PID) controller; the PID controller in
communication with the brake control unit, the PID controller
configured to receive the control signal from the brake control
unit and an adjustment signal from an antiskid brake controller and
output a modified control signal; a wheel speed sensor configured
to output a wheel speed signal indicative of a speed of the wheel
to the antiskid brake controller; and the antiskid brake controller
in communication with the PID controller and with the wheel speed
sensor, the antiskid brake controller configured to receive the
wheel speed signal from the wheel speed sensor and to provide the
adjustment signal to the PID controller; wherein the antiskid brake
controller provides the adjustment signal to the PID controller in
proportion to the wheel speed signal; wherein the modified control
signal is adjusted based on the control signal and the adjustment
signal; and wherein a reset schedule of an integrator of the PID
controller is continually reset based on the wheel speed signal,
and wherein a margin of the reset schedule is varied in proportion
to the speed of the wheel.
2. The brake control system of claim 1, wherein the modified
control signal is adjusted during the braking operation.
3. The brake control system of claim 1, wherein the modified
control signal is adjusted throughout the braking operation.
4. The brake control system of claim 1, wherein the wheel speed
sensor measures the speed of the wheel during the braking
operation.
5. The brake control system of claim 4, wherein the speed of the
wheel is based on measuring an angular velocity of the wheel
multiplied by a radius of the wheel.
6. The brake control system of claim 1, wherein the adjustment
signal is based, at least in part, on at least one of a reference
speed signal and a mu-slip curve.
7. The brake control system of claim 1, wherein the adjustment
signal comprises a first threshold at a first speed and a second
threshold at a second speed, wherein the first speed is slower than
the second speed and the first threshold is smaller than the second
threshold.
8. The brake control system of claim 1, wherein the wheel assembly
is configured for use in an aircraft.
9. A method for controlling a braking operation applied to a wheel
of a wheel assembly, comprising: receiving a command signal in
proportion to an amount of braking requested at an input device;
outputting a control signal in proportion to the command signal;
receiving a wheel speed signal indicative of a speed of the wheel;
calculating an adjustment signal in proportion to the wheel speed
signal; providing a modified control signal to a brake actuator
based on the control signal and the adjustment signal; and
continually resetting a reset schedule based on the wheel speed
signal, wherein a margin of the reset schedule is varied in
proportion to the speed of the wheel.
10. The method for controlling the braking operation of claim 9,
further comprising: braking the wheel in proportion to the modified
control signal.
11. The method for controlling the braking operation of claim 9,
further comprising: adjusting the adjustment signal during the
braking operation.
12. The method for controlling the braking operation of claim 9,
further comprising: adjusting the adjustment signal throughout the
braking operation.
13. The method for controlling the braking operation of claim 9,
further comprising: adjusting the modified control signal during
the braking operation.
14. The method for controlling the braking operation of claim 9,
further comprising: adjusting the modified control signal
throughout the braking operation.
15. The method for controlling the braking operation of claim 9,
further comprising: calculating the adjustment signal based, at
least in part, on at least one of a reference speed signal and a
mu-slip curve.
16. A brake control system for controlling a braking operation
applied to a wheel of a wheel assembly, comprising: a
non-transitory memory configured to store instructions; and one or
more processors in electronic communication with the non-transitory
memory, the one or more processors configured to: receive a command
signal in proportion to an amount of braking requested at an input
device; output a control signal in proportion to the command
signal; receive a wheel speed signal indicative of a speed of the
wheel; calculate an adjustment signal in proportion to the wheel
speed signal; provide a modified control signal to a brake actuator
based on the control signal and the adjustment signal; and
continually reset a reset schedule based on the wheel speed signal,
wherein a margin of the reset schedule is varied in proportion to
the speed of the wheel.
17. The brake control system of claim 16, wherein the one or more
processors are further configured to: brake the wheel in proportion
to the modified control signal.
18. The brake control system of claim 16, wherein the one or more
processors are further configured to at least one of: receive the
wheel speed signal during the braking operation; calculate the
adjustment signal during the braking operation; and provide the
modified control signal during the braking operation.
19. The brake control system of claim 16, wherein the one or more
processors are further configured to at least one of: receive the
wheel speed signal throughout the braking operation; calculate the
adjustment signal throughout the braking operation; and provide the
modified control signal throughout the braking operation.
20. The brake control system of claim 16, wherein the one or more
processors are further configured to: calculate the adjustment
signal based, at least in part, on at least one of a reference
speed signal and a mu-slip curve.
Description
FIELD
[0001] This disclosure relates to braking systems and methods, such
as suitable for use in an aircraft.
BACKGROUND
[0002] Various types of braking systems are known, including, for
example, electrical, mechanical, electromechanical, hydraulic, and
pneumatic braking systems, etc. Each type finds utility in various
applications.
[0003] In aircraft braking and/or other applications, it is easier
to recognize and/or mitigate skids at higher speeds of travel than
it is to do so at slower speeds of travel.
SUMMARY
[0004] In various embodiments, a brake control system for
controlling a braking operation applied to a wheel of a wheel
assembly includes at least the following: a brake control unit
configured to output a control signal to a Proportional Integral
Derivative (PID); the PID controller in communication with the
brake control unit, the PID controller configured to receive the
control signal from the brake control unit and an adjustment signal
from an antiskid brake controller and output a modified control
signal; a wheel speed sensor configured to output a wheel speed
signal indicative of a speed of a wheel to the antiskid brake
controller; and the antiskid brake controller in communication with
the PID controller and with the wheel speed sensor, the antiskid
brake controller configured to receive the wheel speed signal from
the wheel speed sensor and to provide the adjustment signal to the
PID controller; wherein the antiskid brake controller provides the
adjustment signal to the PID controller in proportion to the wheel
speed signal; wherein the modified control signal is adjusted based
on the control signal and the adjustment signal; and wherein a
reset schedule of an integrator of the PID controller is
continually reset based on the wheel speed signal.
[0005] In various embodiments: the modified control signal is
adjusted during the braking operation; and/or the modified control
signal is adjusted throughout the braking operation; and/or the
wheel speed sensor measures a speed of the wheel during the braking
operation; and/or the speed of the wheel is based on measuring an
angular velocity of the wheel multiplied by a radius of the wheel;
and/or the adjustment signal is based, at least in part, on at
least one of a reference speed signal and a mu-slip curve; and/or
the adjustment signal comprises a first threshold at a first speed
and a second threshold at a second speed, wherein the first speed
is slower than the second speed and the first threshold is smaller
than the second threshold; and/or the wheel assembly is configured
for use in an aircraft.
[0006] In various embodiments, a method for controlling a braking
operation applied to a wheel of a wheel assembly includes at least
the following: receiving a command signal in proportion to an
amount of braking requested at an input device; outputting a
control signal in proportion to the command signal; receiving a
wheel speed signal indicative of a speed of the wheel; calculating
an adjustment signal in proportion to the wheel speed signal;
providing a modified control signal to a brake actuator based on
the control signal and the adjustment signal; and continually
resetting a reset schedule based on the wheel speed signal.
[0007] In various embodiments: the method for controlling the
braking operation further includes braking the wheel in proportion
to the modified control signal; and/or adjusting the adjustment
signal during the braking operation; and/or adjusting the
adjustment signal throughout the braking operation; and/or
adjusting the modified control signal during the braking operation;
and/or adjusting the modified control signal throughout the braking
operation; and/or calculating the adjustment signal based, at least
in part, on at least one of a reference speed signal and a mu-slip
curve.
[0008] In various embodiments, a brake control system for
controlling a braking operation applied to a wheel of a wheel
assembly includes at least the following: a non-transitory memory
configured to store instructions; and one or more processors in
electronic communication with the non-transitory memory, the one or
more processors configured to: receive a command signal in
proportion to an amount of braking requested at an input device;
output a control signal in proportion to the command signal;
receive a wheel speed signal indicative of a speed of the wheel;
calculate an adjustment signal in proportion to the wheel speed
signal; provide a modified control signal to a brake actuator based
on the control signal and the adjustment signal; and continually
reset a reset schedule based on the wheel speed signal.
[0009] In various embodiments: the one or more processors are
further configured to: brake the wheel in proportion to the
modified control signal; and/or at least one of receive the wheel
speed signal during the braking operation, calculate the adjustment
signal during the braking operation; and provide the modified
control signal during the braking operation; and/or at least one of
receive the wheel speed signal throughout the braking operation,
calculate the adjustment signal throughout the braking operation,
and provide the modified control signal throughout the braking
operation; and/or calculate the adjustment signal based, at least
in part, on at least one of a reference speed signal and a mu-slip
curve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings illustrate various embodiments
employing the principles described herein and are a part of the
specification. The illustrated embodiments are meant for
description only, and they do not limit the scope of the claims,
and in which:
[0011] FIG. 1 is a representative illustration of an aircraft
having multiple landing gears and wheel assemblies, in accordance
with various embodiments;
[0012] FIG. 2 is a block diagram including several components of
the brake control unit of FIG. 1, in accordance with various
embodiments;
[0013] FIG. 3 is a block diagram of a brake control system
including an antiskid brake controller, in accordance with various
embodiments;
[0014] FIG. 4 is a mu-slip curve, in accordance with various
embodiments;
[0015] FIG. 5 is a cross-sectional view of a part of a brake
assembly, in accordance with various embodiments; and
[0016] FIG. 6 illustrates a method of mitigating a skid that can be
used with the embodiments of FIGS. 1-5, in accordance with various
embodiments.
DETAILED DESCRIPTION
[0017] This detailed description of exemplary embodiments
references the accompanying drawings, which show exemplary
embodiments by way of illustration. While these exemplary
embodiments are described in sufficient detail to enable those
skilled in the art to practice this disclosure, it should be
understood that other embodiments may be realized and that logical
changes and adaptations in design and construction may be made in
accordance with this disclosure and the teachings herein described
without departing from the scope and spirit hereof. Thus, this
detailed description is presented for purposes of illustration only
and not of limitation.
[0018] In accordance with various aspects of this disclosure,
systems and methods are described herein for mitigating the effects
of brake skid, uncontrolled braking, and/or wheel lock
(collectively referred to herein as a skid). In various
embodiments, the systems and methods described herein provide a
dynamic skid response in relation to wheel speed.
[0019] Referring now to FIG. 1, a representative aircraft 10
includes one or more landing gear systems, such as a first landing
gear 12, a second landing gear 14, and a third landing gear 16. In
various embodiments, the second landing gear 14 is also a nose
landing gear for the aircraft 10. Referring generally, the first
landing gear 12, the second landing gear 14, and the third landing
gear 16 support the aircraft 10 when the aircraft 10 is not flying,
such as when the aircraft 10 is taxing, taking off, landing, and/or
parking, as well as when the aircraft 10 is at rest. Operationally,
the first landing gear 12, the second landing gear 14, and the
third landing gear 16 are retractable into a body and/or fuselage
of the aircraft 10 when the aircraft 10 is in flight and/or not
supporting the aircraft 10, in various embodiments.
[0020] While FIG. 1 depicts a representative aircraft 10 for
convenience of illustration, the braking systems and methods
described herein are not limited to aircraft applications, but find
equivalent utility in other brake and brake skid applications as
well, including automotive, locomotive, vehicular, and/or other
applications.
[0021] In various embodiments, the first landing gear 12, the
second landing gear 14, and/or the third landing gear 16 each
include one or more wheel assemblies 18. For example, the first
landing gear 12 includes an outer wheel assembly 18a and an inner
wheel assembly 18b, in various embodiments. In various embodiments,
each of the wheel assemblies 18 includes a brake 20, a wheel 22,
and a wheel speed sensor 24 (see also FIG. 3). For example, the
first landing gear 12 includes a brake 20 within the outer wheel
assembly 18a, in various embodiments. In operation, the various
wheel assemblies 18 receive braking force inputs to apply to the
brake 20 to act on the wheel 22, such as upon receiving a brake
command from a brake control unit (BCU) 26, as elaborated upon
herein.
[0022] In various embodiments, the aircraft 10 includes a BCU 26
aboard the aircraft 10. In various embodiments, the BCU 26
controls, at least various parts of, the braking of the aircraft
10. For example, in various embodiments, the BCU 26 controls
various parameters of braking, such as antiskid braking, automatic
brake control, landing gear retraction, locked wheel protection,
manual brake control, park capabilities, touchdown protection,
etc.
[0023] Referring now also to FIG. 2, the BCU 26 (and/or other
controllers) includes one or more processors 28 and one or more
tangible, non-transitory memories 30 capable of implementing
digital or programmatic logic. In various embodiments, for example,
the processors 28 comprise one or more of an application specific
integrated circuit (ASIC), digital signal processor (DSP), field
programmable gate array (FPGA), general purpose processor, and/or
other programmable logic device, discrete gate, transistor logic,
or discrete hardware components, etc., and the one or more memories
30 store machine-readable instructions that are implemented by the
one or more processors 28 for performing various functions, such as
mitigating the effects of a brake skid at different wheel speeds,
as described herein in various embodiments.
[0024] Referring now also to FIG. 3, in direct braking systems, the
pressure applied to the brake 20 is proportional to the pressure
applied to an input device 32, such as to brake pedals of the
aircraft 10. In augmented braking systems, on the other hand, the
pressure commanded by the input device 32 is controlled and/or
driven by a position sensor and/or pressure sensor proximate the
input device 32. For example, in a hydraulic braking system, a
braking force is applied to the brake 20 in proportion to a force
or pressure detected by a sensor(s) at the input device 32,
transferring braking pressure from the input device 32 to the wheel
assembly 18 and to the brake 20.
[0025] In various embodiments, an antiskid brake controller 34
compares the speed of the aircraft 10 derived from the wheel speed
sensor 24 to the speed of the aircraft 10 derived from a reference
source. Accordingly, if the wheel 22 is determined to be slipping
by an excessive amount (i.e., skidding), then brake pressure
applied to that wheel 22 is released, and the wheel 22 is allowed
to spin-up to an appropriate speed before the BCU 26 begins braking
that wheel 22 again.
[0026] In various embodiments, the antiskid brake controller 34
responds according to a mu-slip curve 36 with a peak 40, such as
shown in FIG. 4. Mu (i.e., mu or u) is the coefficient of friction
between the wheel 22 and a running surface, such as a runway 38
(see FIG. 1), and a mu-slip curve 36 plots slip ratio against mu.
Referring generally, a difference between wheel velocity and
vehicle velocity is referred to as slip velocity, and slip ratios
are calculated by dividing slip velocities by vehicle velocities.
In the mu-slip curve 36 in FIG. 4, for example, slip ratio is
plotted on a first (e.g., x) axis, and the coefficient of friction
mu is plotted on a second (e.g., y) axis orthogonal to the first
axis. However, mu also changes in relationship to the temperature
of the brake 20. For example, as the brake 20 is used, it requires
less pressure to generate an equivalent torque during the course of
a stop. Accordingly, the schedule of an integrator I of a
Proportional Integral Derivative (PID) controller 44 is tailored to
mitigate this effect. During lower temperature mu periods, for
example, the threshold to detect a skid is tighter, and during
higher temperature mu periods, for example, the thresholds are
varied proportionately. Referring generally, a high slip ratio
implies the brake 20 is undergoing a skid, and the BCU 26 undergoes
skid remediation (e.g., the BCU 26 briefly releases the brake 20
and then reapplies the brake 20) to correct the skid. In various
embodiments, however, it is more difficult to mitigate the skid at
lower wheel speeds. As a result, the threshold of the slip ratio is
varied--e.g., lowered at lower speeds to detect more skids and
trigger skid mitigation, and higher at higher speeds to allow more
skids--according to wheel speed and continually checked against a
reference speed during and throughout the course of a braking event
(e.g., a slowdown, stop, etc.).
[0027] In various embodiments, the PID controller 44 is a three
term controller comprising a control loop feedback mechanism that
continually calculates an error value as a difference between a
control signal T.sub.OUTPUT and a modified control signal
T.sub.OUTPUT', as will be elaborated upon. More specifically, the
PID controller 44, as a feedback controller, applies a correction
based on proportional, integral, and derivative terms input
thereinto.
[0028] Referring again to FIG. 3, during a braking event, an
operator activates the input device 32 to request a braking
function from the BCU 26, and that activation is converted into a
command signal T.sub.C indicative of the amount of activation
requested by the input device 32. The command signal T.sub.C is
provided to the BCU 26, which outputs the control signal
T.sub.OUTPUT in proportion to the command signal T.sub.C.
[0029] In various embodiments, the BCU 26 provides the control
signal T.sub.OUTPUT to a brake actuator 42 in communication
therewith. In various embodiments, the brake actuator 42 is an
electromechanical, hydraulic, pneumatic, or other type of actuator,
and it applies braking pressure to the wheel assembly 18, such as
by exerting a braking force (or torque) through the brake 20 to the
wheel 22 in order to stop or slow the wheel 22.
[0030] In various embodiments, the wheel speed sensor 24 of the
wheel assembly 18 measures the speed of the wheel 22, including
during braking operations. In various embodiments, the speed of the
wheel 22 is based on measuring an angular velocity of the wheel 22
multiplied by a radius of the wheel 22, and the wheel speed sensor
24 outputs a wheel speed signal V.sub.WHEEL of the wheel 22 to the
antiskid brake controller 34.
[0031] In various embodiments, the antiskid brake controller 34
receives the wheel speed signal V.sub.WHEEL and compares it to a
reference speed signal V.sub.REFERENCE to determine a wheel speed
error. This occurs throughout the braking operation, for which the
wheel speed sensor 24 periodically and/or continually outputs the
wheel speed signal V.sub.WHEEL to the antiskid brake controller 34
multiple times during the braking operation.
[0032] Based on the wheel speed signal V.sub.WHEEL, the antiskid
brake controller 34 calculates the wheel speed error and sends an
adjustment signal K to the integrator I of the PID controller 44,
which is intermediate the BCU 26 and the brake actuator 42. If the
wheel speed error is large in relation to the wheel speed signal
V.sub.WHEEL, the antiskid brake controller 34 determines that a
skid is occurring, and the adjustment signal K is large. On the
other hand, if the wheel speed error is small in relation to the
wheel speed signal V.sub.WHEEL, the antiskid brake controller 34
determines that a skid is not occurring, and the adjustment signal
K is small and/or zero.
[0033] In either event, the PID controller 44 receives the
adjustment signal K from the antiskid brake controller 34 and
adjusts the control signal T.sub.OUTPUT into the modified control
signal T.sub.OUTPUT' that is input into the brake actuator 42 to
control the brake assembly 18, as implemented by the PID controller
44. The PID controller 44 calculates a difference between its
setpoint and its feedback, called the error, and it eliminates the
error. A PID control algorithm executed by the PID controller 44
varies the proportional, integral, and derivative terms to set a
desired response, with the proportional term proportional to the
error, the integral term proportional to the integral of the error,
and the derivative term proportional to the derivative of the
error.
[0034] Since the antiskid brake controller 34 calculates the wheel
speed error many times over in real-time during braking operations,
the antiskid brake controller 34 is continually adjusting the
adjustment signal K based on the wheel speed signal V.sub.WHEEL.
When the wheel speed error is small in relation to wheel speed
(i.e., no skid), the modified control signal T.sub.OUTPUT' is the
same or approximately the same as the control signal T.sub.OUTPUT
from the BCU 26. However, when the wheel speed error is large in
relation to wheel speed (i.e., skid), the modified control signal
T.sub.OUTPUT' will deviate more substantially from the control
signal T.sub.OUTPUT from the BCU 26, thereby allowing the brake
actuator 42 to dynamically adjust braking the wheel assembly 18 as
to the occurrence of a possible skid in relation to wheel speed.
Accordingly, the reset schedule of the integrator I is continually
reset based on wheel speed, and the margins of the PID controller's
44 reset schedule are varied in proportion to wheel speed. This
provides for improved detection and/or mitigation of skids at
slower wheel speeds, where they are harder to detect and mitigate
relative to detecting and/or mitigating skids at higher wheel
speeds.
[0035] Referring now also to FIG. 5, a cross-sectional view of a
part of the brake assembly 18 is illustrated, in accordance with
various embodiments. In various embodiments, the brake assembly 18
comprises a bogie axle 112, the wheel 22, including a hub 116, a
wheel well 118, a web 120, a torque take-out assembly 122, one or
more torque bars 124, a wheel rotational axis 126, a wheel well
recess 128, the brake actuator 42, multiple brake rotors 52,
multiple brake stators 54, a pressure plate 56, an end plate 58, a
ram 60, multiple torque bar bolts 148, a torque bar pin 151,
multiple rotor lugs 154, and multiple stator slots 156.
[0036] Brake disks (e.g., the interleaved brake rotors 52 and brake
stators 54) are disposed in the wheel well recess 128 of the wheel
well 118. In various embodiments, the brake rotors 52 and the brake
stators 54 are referred to collectively as a brake stack or heat
sink. In various embodiments, the brake rotors 52 are secured to
the torque bars 124 for rotating with the wheel 22, while the brake
stators 54 are, in various embodiments, engaged with the torque
take-out assembly 122. In various embodiments, at least one brake
actuator 42 is operable to compress the interleaved brake rotors 52
and the brake stators 54 for stopping the aircraft 10 of FIG. 1. In
the embodiment of FIG. 5, the brake actuator 42 is shown as a
hydraulically actuated piston, although pistons driven
pneumatically and/or by electromechanical actuators are also
contemplated herein, in various embodiments. The pressure plate 56
and the end plate 58 are disposed at opposite ends of the
interleaved brake rotors 52 and the brake stators 54, and the ram
60 is disposed proximate the pressure plate 56.
[0037] Through compression of the brake rotors 52 and the brake
stators 54 between the pressure plate 56 and the end plate 58, the
resulting frictional contact slows, stops, and/or prevents rotation
of the wheel 22. In various embodiments, the torque take-out
assembly 122 is secured to a stationary portion of a landing gear
truck, such as a bogie beam or other landing gear strut, such that
the torque take-out assembly 122 and the brake stators 54 are
prevented from rotating during braking of the aircraft 10 of FIG.
1.
[0038] Referring now also to FIG. 6, a method for controlling
braking operations (e.g., controlling skids) as applied to a wheel
22 of a wheel assembly 18 is illustrated, in accordance with
various embodiments. More specifically, the method 200 begins in a
step 202, after which a command signal T.sub.C is received from an
input device 32 in proportion to an amount of braking requested at
the input device 32 at a step 204. In various embodiments, the
command signal T.sub.C is received by the BCU 26, which outputs a
control signal T.sub.OUTPUT in proportion to the command signal
T.sub.C at a step 206. In addition, a wheel speed signal
V.sub.WHEEL is calculated by a wheel speed sensor 24 and received
by an antiskid brake controller 34 at a step 208, the wheel speed
signal V.sub.WHEEL indicative of a speed of the wheel 22 of the
wheel assembly 18. In addition, the antiskid brake controller 34
calculates an adjustment signal K in proportion to the wheel speed
signal V.sub.WHEEL in a step 210. In various embodiments, the
antiskid brake controller 34 provides the adjustment signal K to
the PID controller 44, which receives the control signal
T.sub.OUTPUT and the adjustment signal K. The PID controller 44
provides a modified control signal T.sub.OUTPUT' based on the
control signal T.sub.OUTPUT and the adjustment signal K to a brake
actuator 42 in communication with the wheel assembly 18 at a step
212, after which the method 200 ends in step 214.
[0039] In accordance with the description herein, technical
benefits and effects of this disclosure include mitigating the
effects of brake skids at different speeds. In various embodiments,
the systems and methods mitigate skids differently at different
speeds by transmitting an adjustment signal to an integrator to
adjust a control signal and an adjustment signal K into a modified
control signal in order to command a brake actuator.
[0040] Advantages, benefits, and solutions to problems have been
described herein with regard to specific embodiments. Furthermore,
connecting lines shown in the various figures contained herein are
intended to represent exemplary functional relationships and/or
physical couplings between the various elements. It should be noted
that many additional or alternative functional relationships or
physical connections may be present in a practical system. However,
the advantages, benefits, solutions to problems, and any elements
that may cause any advantage, benefit, or solution to occur or
become more pronounced are not to be construed as critical,
essential, or required elements or features of this disclosure.
[0041] The scope of this disclosure is accordingly to be limited by
nothing other than the appended claims, in which reference to an
element in the singular is not intended to mean "one and only one"
unless explicitly so stated, but rather "one or more." It is to be
understood that unless specifically stated otherwise, references to
"a," "an," and/or "the" may include one or more than one, and that
reference to an item in the singular may also include the item in
the plural, and vice-versa. All ranges and ratio limits disclosed
herein may be combined.
[0042] Moreover, where a phrase similar to "at least one of A, B,
and C" is used in the claims, it is intended that the phrase be
interpreted to mean that A alone may be present in an embodiment, B
alone may be present in an embodiment, C alone may be present in an
embodiment, or that any combination of the elements A, B, and C may
be present in a single embodiment; for example, A and B, A and C, B
and C, or A and B and C. Different cross-hatching may be used
throughout the figures to denote different parts, but not
necessarily to denote the same or different materials. Like
depictions and numerals also generally represent like elements.
[0043] The steps recited in any of the method or process
descriptions may be executed in any order and are not necessarily
limited to the order presented. Furthermore, any reference to
singular elements, embodiments, and/or steps includes plurals
thereof, and any reference to more than one element, embodiment,
and/or step may include a singular one thereof. Elements and steps
in the figures are illustrated for simplicity and clarity and have
not necessarily been rendered according to any particular sequence.
For example, steps that may be performed concurrently or in
different order are only illustrated in the figures to help to
improve understanding of embodiments of the present, representative
disclosure.
[0044] Any reference to attached, connected, fixed, or the like may
include full, partial, permanent, removable, temporary and/or any
other possible attachment option. Additionally, any reference to
without contact (or similar phrases) may also include reduced
contact or minimal contact. Surface shading lines may be used
throughout the figures to denote different areas or parts, but not
necessarily to denote the same or different materials. In some
cases, reference coordinates may or may not be specific to each
figure.
[0045] Apparatus, methods, and systems are provided herein. In the
detailed description herein, references to "one embodiment," "an
embodiment," "various embodiments," etc., indicate that the
embodiment described may include a particular characteristic,
feature, or structure, but every embodiment may not necessarily
include this particular characteristic, feature, or structure.
Moreover, such phrases may not necessarily refer to the same
embodiment. Further, when a particular characteristic, feature, or
structure is described in connection with an embodiment, it is
submitted that it is within the knowledge of one skilled in the art
to affect such characteristic, feature, or structure in connection
with other embodiments, whether or not explicitly described. After
reading the description, it will be apparent to one skilled in the
relevant art(s) how to implement this disclosure in alternative
embodiments.
[0046] Furthermore, no component, element, or method step in the
present disclosure is intended to be dedicated to the public
regardless of whether the component, element, or method step is
explicitly recited in the claims. No claim element is intended to
invoke 35 U.S.C. .sctn. 112(f) unless the element is expressly
recited using the phrase "means for." As used herein, the terms
"comprises," "comprising," or any other variation thereof, are
intended to cover a non-exclusive inclusion, such that an
apparatus, article, method, or process that comprises a list of
elements does not include only those elements, but it may also
include other elements not expressly listed or inherent to such
apparatus, article, method, or process.
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