CROSS REFERENCE TO RELATED APPLICATION
TECHNICAL FIELD
[0002] The present invention generally relates to aircraft operations, and more particularly
relates to generation of a heading intercept advisory for a flight plan of an aircraft.
BACKGROUND
[0003] Aircraft flight management system performs numerous computations within a flight
plan based on waypoints picked up from various navigation databases. The predictions
for intercepts to resume a flight path are displayed between waypoint-to-waypoint
or leg-to-leg along the flight plan path. However, a pilot often needs to see flight
prediction data for an intercept for a point which is between waypoints of the flight
plan. Hence, there is a need for a method and system for generating a heading intercept
advisory.
BRIEF SUMMARY
[0004] This summary is provided to describe select concepts in a simplified form that are
further described in the Detailed Description. This summary is not intended to identify
key or essential features of the claimed subject matter, nor is it intended to be
used as an aid in determining the scope of the claimed subject matter.
[0005] A method is provided for optimizing an aircraft heading for an intercept of a flight
plan. The method comprises: activating a flight plan intercept advisory function on
a flight management system (FMS) for an aircraft when the aircraft deviates from an
active flight plan, or when aircraft is commanded to fly a heading direction deviating
from the current flight plan path, where the flight plan intercept advisory function,
identifies at least one intercept point of the active flight plan that is based on
an aircraft heading that is selected by a pilot of the aircraft, and calculates predicted
compliance with flight performance and operational parameters of the aircraft at each
intercept point; and displaying the predicted compliance of flight performance and
operational parameters of the aircraft at each intercept point to the pilot of the
aircraft.
[0006] A system is provided for optimizing an aircraft heading for an intercept of a flight
plan. The system comprises: a flight management system (FMS) for an aircraft that
contains a flight plan intercept advisory function that is activated when the aircraft
deviates from an active flight plan for an aircraft, where the flight plan intercept
advisory function, identifies at least one intercept point of the active flight plan
that is based on an aircraft heading that is selected by a pilot of the aircraft,
and calculates predicted compliance with flight performance and operational parameters
of the aircraft at each intercept point; and a display that shows the predicted compliance
of flight performance and operational parameters of the aircraft at each intercept
point to the pilot of the aircraft.
[0007] Furthermore, other desirable features and characteristics of the various embodiments
will become apparent from the subsequent detailed description and the appended claims,
taken in conjunction with the accompanying drawings and the preceding background.
BRIEF DESCRIPTION OF DRAWINGS
[0008] The present disclosure will hereinafter be described in conjunction with the following
drawing figures, wherein like numerals denote like elements, and wherein:
FIG. 1 shows a diagram of aircraft computer system in accordance with the disclosed
embodiments;
FIG.2 shows a functional block diagram of a computing device in accordance with the
disclosed embodiments;
FIG.3 shows a display of an active flight plan for an aircraft in accordance with
the disclosed embodiments;
FIG.4 shows a display of a nearest to waypoint intercept of an active flight plan
for an aircraft in accordance with the disclosed embodiments;
FIG. 5 shows a display of a nearest to destination intercept of an active flight plan
for an aircraft in accordance with the disclosed embodiments;
FIG. 6 shows a display of a nearest and stable intercept of an active flight plan
for an aircraft in accordance with the disclosed embodiments;
FIG. 7 shows a display of multiple waypoint intercepts of an active flight plan for
an aircraft in accordance with the disclosed embodiments;
FIG. 8 shows a display of multiple waypoint intercept of an active flight plan for
an aircraft in accordance with the disclosed embodiments; and
FIG. 9 shows a flowchart for optimizing an aircraft heading for an intercept of a
flight plan with the disclosed embodiments.
DETAILED DESCRIPTION
[0009] The following detailed description is merely exemplary in nature and is not intended
to limit the invention or the application and uses of the invention. As used herein,
the word "exemplary" means "serving as an example, instance, or illustration." Thus,
any embodiment described herein as "exemplary" is not necessarily to be construed
as preferred or advantageous over other embodiments. All of the embodiments described
herein are exemplary embodiments provided to enable persons skilled in the art to
make or use the invention and not to limit the scope of the invention which is defined
by the claims. Furthermore, there is no intention to be bound by any expressed or
implied theory presented in the preceding technical field, background, brief summary,
or the following detailed description.
[0010] A method and system for optimizing an aircraft heading for an intercept of a flight
plan has been developed. The method includes activating a flight plan intercept advisory
function on a flight management system (FMS) for the aircraft when an aircraft deviates
from the active flight plan of the aircraft. In other examples, the aircraft is currently
on the flight plan and is vectored by air traffic control (ATC) to certain heading
directions. The flight plan intercept advisory function identifies intercept points
of the active flight plan that is based on an aircraft heading that is selected by
a pilot of the aircraft. The advisory function calculates predicted compliance with
flight performance and operational parameters of the aircraft at each intercept point.
The predicted compliance of flight performance and operational parameters of the aircraft
at each intercept point are then displayed to the pilot of the aircraft. When no intercept
points are identified based on the current heading direction, the advisory function
may prompt pilots with available intercept heading directions and range which allows
the pilot to rejoin the flight plan upon a request to the ATC.
[0011] Turning now to the figures, FIG. 1 is a diagram of aircraft computer system 100,
in accordance with the disclosed embodiments. The computing device 102 may be implemented
by any computing device that includes at least one processor, some form of memory
hardware, a user interface, and communication hardware. For example, the computing
device 102 may be implemented using a personal computing device, such as a tablet
computer, a laptop computer, a personal digital assistant (PDA), a smartphone, or
the like. In this scenario, the computing device 102 is capable of storing, maintaining,
and executing Electronic Flight Bag (EFB) applications. In other embodiments, the
computing device 102 may be implemented using a computer system onboard the aircraft
104.
[0012] The aircraft 104 may be implemented as an airplane, helicopter, spacecraft, hovercraft,
or the like. The one or more avionics systems 106 may include a Flight Management
System (FMS), navigation devices, weather detection devices, radar devices, communication
devices, brake systems, and/or any other electronic system or avionics system used
to operate the aircraft 104. Data obtained from the one or more avionics systems 106
may include, without limitation: flight data, aircraft heading, aircraft speed, aircraft
position, altitude, descent rate, position of air spaces surrounding a current flight
plan, activity of air spaces surrounding a current flight plan, energy assessment
of the aircraft or the like.
[0013] The FMS, as is generally known, is a specialized computer that automates a variety
of in-flight tasks such as in-flight management of the flight plan. Using various
sensors such as global positioning system (GPS), the FMS determines the aircraft's
position and guides the aircraft along its flight plan using its navigation database.
From the cockpit, the FMS is normally controlled through a visual display device such
as a control display unit (CDU) which incorporates a small screen, a keyboard or a
touchscreen. The FMS displays the flight plan and other critical flight data to the
aircrew during operation.
[0014] The FMS may have a built-in electronic memory system that contains a navigation database.
The navigation database contains elements used for constructing a flight plan. In
some embodiments, the navigation database may be separate from the FMS and located
onboard the aircraft while in other embodiments the navigation database may be located
on the ground and relevant data provided to the FMS via a communications link with
a ground station. The navigation database used by the FMS may typically include: waypoints/intersections;
airways; radio navigation aids/navigation beacons; airports; runway; standard instrument
departure (SID) information; standard terminal arrival (STAR) information; holding
patterns; and instrument approach procedures. Additionally, other waypoints may also
be manually defined by pilots along the route.
[0015] The flight plan is generally determined on the ground before departure by either
the pilot or a dispatcher for the owner of the aircraft. It may be manually entered
into the FMS or selected from a library of common routes. In other embodiments the
flight plan may be loaded via a communications data link from an airline dispatch
center. During preflight planning, additional relevant aircraft performance data may
be entered including information such as: gross aircraft weight; fuel weight and the
center of gravity of the aircraft. The aircrew may use the FMS to modify the flight
plan before takeoff or even while in flight for variety of reasons. Such changes may
be entered via the CDU. Once in flight, the principal task of the FMS is to accurately
monitor the aircraft's position. This may use a GPS, a VHF omnidirectional range (VOR)
system, or other similar sensor in order to determine and validate the aircraft's
exact position. The FMS constantly cross checks among various sensors to determine
the aircraft's position with accuracy.
[0016] Additionally, the FMS may be used to perform advanced vertical navigation (VNAV)
functions. The purpose of VNAV is to predict and optimize the vertical path of the
aircraft. The FMS provides guidance that includes control of the pitch axis and of
the throttle of the aircraft. In order to accomplish these tasks, the FMS has detailed
flight and engine model data of the aircraft. Using this information, the FMS may
build a predicted vertical descent path for the aircraft along with an aircraft energy
assessment. A correct and accurate implementation of VNAV has significant advantages
in fuel savings and on-time efficiency.
[0017] The server system 108 may include any number of application servers, and each server
may be implemented using any suitable computer. In some embodiments, the server system
108 includes one or more dedicated computers. In some embodiments, the server system
108 includes one or more computers carrying out other functionality in addition to
server operations. The server system 108 may store and provide any type of data in
various databases. Such data may include, without limitation: flight plan data, aircraft
parameters, avionics data and associated user actions, and other data compatible with
the computing device 200.
[0018] The computing device 102 is usually located onboard the aircraft 104, and the computing
device 102 communicates with the one or more avionics systems 106 via wired and/or
wireless communication connection. The computing device 102 and the server system
108 may both be located onboard the aircraft 104. In other embodiments, the computing
device 102 and the server system 108 may be disparately located, and the computing
device 102 communicates with the server system 108 via the data communication network
110 and/or via communication mechanisms onboard the aircraft 104.
[0019] The data communication network 110 may be any digital or other communications network
capable of transmitting messages or data between devices, systems, or components.
In certain embodiments, the data communication network 110 includes a packet switched
network that facilitates packet-based data communication, addressing, and data routing.
The packet switched network could be, for example, a wide area network, the Internet,
or the like. In various embodiments, the data communication network 110 includes any
number of public or private data connections, links or network connections supporting
any number of communications protocols. The data communication network 110 may include
the Internet, for example, or any other network based upon TCP/IP or other conventional
protocols. In various embodiments, the data communication network 110 could also incorporate
a wireless and/or wired telephone network, such as a cellular communications network
for communicating with mobile phones, personal digital assistants, and/or the like.
The data communication network 110 may also incorporate any sort of wireless or wired
local and/or personal area networks, such as one or more IEEE 802.3, IEEE 802.16,
and/or IEEE 802.11 networks, and/or networks that implement a short range (e.g., Bluetooth)
protocol. For the sake of brevity, conventional techniques related to data transmission,
signaling, network control, and other functional aspects of the systems (and the individual
operating components of the systems) may not be described in detail herein.
[0020] FIG. 2 is a functional block diagram of a computing device 200, in accordance with
the disclosed embodiments. It should be noted that the computing device 200 can be
implemented with the computing device 102 depicted in FIG. 1. In this regard, the
computing device 200 shows certain elements and components of the computing device
102 in more detail.
[0021] The computing device 200 generally includes, without limitation: a processor 202;
system memory 204; a user interface 206; a plurality of sensors 208; a communication
device 210; an FMS 212; and a display device 216. These elements and features of the
computing device 200 may be operatively associated with one another, coupled to one
another, or otherwise configured to cooperate with one another as needed to support
the desired functionality. For ease of illustration and clarity, the various physical,
electrical, and logical couplings and interconnections for these elements and features
are not depicted in FIG. 2. Moreover, it should be appreciated that embodiments of
the computing device 200 will include other elements, modules, and features that cooperate
to support the desired functionality. For simplicity, FIG. 2 only depicts certain
elements that are described in more detail below.
[0022] The processor 202 may be implemented or performed with one or more general purpose
processors, a content addressable memory, a digital signal processor, an application
specific integrated circuit, a field programmable gate array, any suitable programmable
logic device, discrete gate or transistor logic, discrete hardware components, or
any combination designed to perform the functions described here. In particular, the
processor 202 may be realized as one or more microprocessors, controllers, microcontrollers,
or state machines. Moreover, the processor 202 may be implemented as a combination
of computing devices, e.g., a combination of digital signal processors and microprocessors,
a plurality of microprocessors, one or more microprocessors in conjunction with a
digital signal processor core, or any other such configuration.
[0023] The processor 202 is communicatively coupled to the system memory 204. The system
memory 204 is configured to store any obtained or generated data associated with generating
alerts to redirect user attention from the computing device 200 to a critical or high-priority
flight situation. The system memory 204 may be realized using any number of devices,
components, or modules, as appropriate to the embodiment. Moreover, the computing
device 200 could include system memory 204 integrated therein and/or a system memory
204 operatively coupled thereto, as appropriate to the particular embodiment. In practice,
the system memory 204 could be realized as RAM memory, flash memory, EPROM memory,
EEPROM memory, registers, a hard disk, a removable disk, or any other form of storage
medium known in the art. In certain embodiments, the system memory 204 includes a
hard disk, which may also be used to support functions of the computing device 200.
The system memory 204 can be coupled to the processor 202 such that the processor
202 can read information from, and write information to, the system memory 204. In
the alternative, the system memory 204 may be integral to the processor 202. As an
example, the processor 202 and the system memory 204 may reside in a suitably designed
application-specific integrated circuit (ASIC).
[0024] The user interface 206 may include or cooperate with various features to allow a
user to interact with the computing device 200. Accordingly, the user interface 206
may include various human-to-machine interfaces, e.g., a keypad, keys, a keyboard,
buttons, switches, knobs, a touchpad, a joystick, a pointing device, a virtual writing
tablet, a touch screen, a microphone, or any device, component, or function that enables
the user to select options, input information, or otherwise control the operation
of the computing device 200. For example, the user interface 206 could be manipulated
by an operator to provide flight data parameters during the operation of electronic
flight bag (EFB) applications, as described herein.
[0025] In certain embodiments, the user interface 206 may include or cooperate with various
features to allow a user to interact with the computing device 200 via graphical elements
rendered on a display element (e.g., the display device 216). Accordingly, the user
interface 206 may initiate the creation, maintenance, and presentation of a graphical
user interface (GUI). In certain embodiments, the display device 216 implements touch-sensitive
technology for purposes of interacting with the GUI. Thus, a user can manipulate the
GUI by moving a cursor symbol rendered on the display device 216, or by physically
interacting with the display device 216 itself for recognition and interpretation,
via the user interface 206.
[0026] The plurality of sensors 208 is configured to obtain data associated with active
use of the computing device 200, and may include, without limitation: touchscreen
sensors, accelerometers, gyroscopes, or the like. Some embodiments of the computing
device 200 may include one particular type of sensor, and some embodiments may include
a combination of different types of sensors. Generally, the plurality of sensors 208
provides data indicating whether the computing device 200 is currently being used.
Touchscreen sensors may provide output affirming that the user is currently making
physical contact with the touchscreen (e.g., a user interface 206 and/or display device
216 of the computing device 200), indicating active use of the computing device. Accelerometers
and/or gyroscopes may provide output affirming that the computing device 200 is in
motion, indicating active use of the computing device 200.
[0027] The communication device 210 is suitably configured to communicate data between the
computing device 200 and one or more remote servers and one or more avionics systems
onboard an aircraft. The communication device 210 may transmit and receive communications
over a wireless local area network (WLAN), the Internet, a satellite uplink/downlink,
a cellular network, a broadband network, a wide area network, or the like. As described
in more detail below, data received by the communication device 210 may include, without
limitation: avionics systems data and aircraft parameters (e.g., a heading for the
aircraft, aircraft speed, altitude, aircraft position, ascent rate, descent rate,
a current flight plan, a position of air spaces around a current flight plan, and
activity of the air spaces around a current flight plan), and other data compatible
with the computing device 200. Data provided by the communication device 210 may include,
without limitation, requests for avionics systems data, alerts and associated detail
for display via an aircraft onboard display, and the like.
[0028] The display device 216 is configured to display various icons, text, and/or graphical
elements associated with alerts related to situations requiring user attention, wherein
the situations are associated with a device or system that is separate and distinct
from the computing device 200. In an exemplary embodiment, the display device 216
and the user interface 206 are communicatively coupled to the processor 202. The processor
202, the user interface 206, and the display device 216 are cooperatively configured
to display, render, or otherwise convey one or more graphical representations or images
associated with high-priority or critical flight situation alerts on the display device
216, as described in greater detail below. In an exemplary embodiment, the display
device 216 is realized as an electronic display configured to graphically display
critical flight situation alerts and associated detail, as described herein. In some
embodiments, the computing device 200 is an integrated computer system onboard an
aircraft, and the display device 216 is located within a cockpit of the aircraft and
is thus implemented as an aircraft display. In other embodiments, the display device
216 is implemented as a display screen of a standalone, personal computing device
(e.g., laptop computer, tablet computer). It will be appreciated that although the
display device 216 may be implemented using a single display, certain embodiments
may use additional displays (i.e., a plurality of displays) to accomplish the functionality
of the display device 216 described herein.
[0029] Turning now to FIG.3, a display 300 is shown of an active flight plan for an aircraft
302 in accordance with the disclosed embodiments. In this example, the flight plan
for the aircraft 302 has a destination of runway "R27" 304 while passing through various
waypoints 306 labeled "NXI,", "OXI," and "FXL". The segments of the flight plan between
the waypoints are called "legs". In typical aircraft operations, air traffic control
(ATC) may vector an airplane away from originally planned flight path due to traffic,
weather conditions, etc. The pilot may rejoin the planned path at a point in-between
when allowed. However, the operational flight parameters such as that energy state
of vector-to-rejoin the planned path information relative to intended approach and
landing operations needs to be calculated.
[0030] In present embodiments, the pilot dials in a heading/track interceptor line so that
it intercepts a point in a leg segment. The system will calculate and display on a
pilot-configured FMS the selected intercept data. The intercept data shown includes:
the aircraft energy state (typically listed as "stable" or "unstable"); speed; altitude,
distance to go (DTG) to a selected point such a waypoint or destination; fuel remaining;
aircraft constraints; etc.). This directly saves pilots time and enables quick situational
awareness.
[0031] When the aircraft is operating in a heading/track intercept mode, the heading intercept
line will be used to show FMS predictions whenever pilot dials the heading knob over
the active flight plan with an intercept. A dynamic computation is performed to periodically
evaluate aircraft operation parameters (
e.g., energy state along the path, speed, altitude, deviation, etc.). Graphic indications
are generated and display from intercept point and subsequent path in 2D/3D/4D reflecting
the aircraft parameter state relevant to the current approach and landing operations.
There may be one or more intercepts to the selected heading and all intercepts position
will show respective FMS predictions. In such embodiments, the intercept advisory
will show combinations of advisories. Favorable and unfavorable paths and conditions,
as characterized by the aircraft parameters relative to the approach and landing operations
may also be displayed. Advisories with different predictive values may be color coded
(
e.g., Green/Yellow/White) and/or have a varied shape of the symbol
(e.g., Continuous Diamond/Dashed Diamond) to denote predictive values at the intercept point.
[0032] In some embodiments, the intercept advisory may be an add-on layer to existing aircraft
systems and displays. The intercept advisory is configurable to turn-on and turn-off
of various features. The intercept advisory will have sub-menus to select pilot preferred
values for the features to be displayed. The pilot may have an option to select his/her
preferred intercept and activate it for further navigation. Textural or graphic selection
mechanisms are provided to allow pilots to select /insert/activate the favorable path
selections. In other embodiments, the intercept advisory will have options to show
the tolerance (
e.g., in NM) to the closest active flight plan and recommend the direction of turn to have
an active intercept. Also, the intercept advisory may recommend an intercept name
using the PBD (Place-Bearing-Distance) principle. Also, an automated path selection
and activation function for a favorable path may be used when aircraft parameters
are with a preselected range.
[0033] In the following examples, a flight plan has been constructed to an active runway
with waypoints NXL, OXL, FXL and destination RWY27. The pilot is flying in fully "managed
mode". In other embodiments, the pilot may be flying in "manual mode" (e.g., heading
mode). The pilot dials a heading knob in such a way that it intecepts existing active
flight plan. The system automatically displays specific selected attributes at the
intercept points. Turning now to FIG.4, a display 400 is shown of a nearest to waypoint
intercept of an active flight plan for an aircraft in accordance with the disclosed
embodiments. This is an example of nearest intercept to immediate next leg 406 which
can be intercepted. Turning now to FIG. 5, a display 500 is shown of a nearest to
destination intercept of an active flight plan for an aircraft in accordance with
the disclosed embodiments. This is an example to show an intercept point that is calculated
to be the shortest distance to the destination runway R27 504. This intercept point
is obtained by dailing the heading knob when this feaure is activated. Turning now
to FIG. 6, a display 600 is shown of the nearest intercept that is also stable 604
of an active flight plan for an aircraft 602 in accordance with the disclosed embodiments.
[0034] Turning now to FIG. 7, a display 700 is shown of multiple waypoint intercepts of
an active flight plan for an aircraft 702 in accordance with the disclosed embodiments.
Turning now to FIG. 8, a display 800 is shown of multiple waypoint intercepts 804
of an active flight plan for an aircraft 802 in accordance with the disclosed embodiments.
In these examples, the heading intercept is used to determine FMS operational predictions
(
e.g., aircraft energy states at multiple places) of each of the intercept points before
even flying to that location just by dialing the heading knob.
[0035] Turning now to FIG. 9, a flowchart 900 is shown for optimizing an aircraft heading
for an intercept of a flight plan with the disclosed embodiments. First, a flight
plan intercept advisory function is activated 902 on a flight management system (FMS)
for the aircraft when an aircraft deviates from the active flight plan of the aircraft.
In some embodiments, the aircraft deviates from the active flight plan when the aircraft
is operating in manual mode as opposed to a managed mode (e.g., NAV mode). The flight
plan intercept advisory function identifies intercept points 904 of the active flight
plan that is based on an aircraft heading that is selected by a pilot of the aircraft.
The advisory function calculates predicted compliance 906 with flight performance
and operational parameters of the aircraft at each intercept point. This continues
908 until all of the of the identified intercept points have their respective compliance
data predicted. Once completed for every intercept point, the predicted compliance
of flight performance and operational parameters of the aircraft at each point are
then displayed 910 to the pilot of the aircraft.
[0036] Those of skill in the art will appreciate that the various illustrative logical blocks,
modules, circuits, and algorithm steps described in connection with the embodiments
disclosed herein may be implemented as electronic hardware, computer software, or
combinations of both. Some of the embodiments and implementations are described above
in terms of functional and/or logical block components (or modules) and various processing
steps. However, it should be appreciated that such block components (or modules) may
be realized by any number of hardware, software, and/or firmware components configured
to perform the specified functions. To clearly illustrate this interchangeability
of hardware and software, various illustrative components, blocks, modules, circuits,
and steps have been described above generally in terms of their functionality. Whether
such functionality is implemented as hardware or software depends upon the particular
application and design constraints imposed on the overall system. Skilled artisans
may implement the described functionality in varying ways for each particular application,
but such implementation decisions should not be interpreted as causing a departure
from the scope of the present invention. For example, an embodiment of a system or
a component may employ various integrated circuit components, e.g., memory elements,
digital signal processing elements, logic elements, look-up tables, or the like, which
may carry out a variety of functions under the control of one or more microprocessors
or other control devices. In addition, those skilled in the art will appreciate that
embodiments described herein are merely exemplary implementations.
[0037] The various illustrative logical blocks, modules, and circuits described in connection
with the embodiments disclosed herein may be implemented or performed with a general
purpose processor, a digital signal processor (DSP), an application specific integrated
circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic
device, discrete gate or transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A general-purpose processor
may be a microprocessor, but in the alternative, the processor may be any conventional
processor, controller, microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a combination of a DSP and
a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction
with a DSP core, or any other such configuration.
[0038] The steps of a method or algorithm described in connection with the embodiments disclosed
herein may be embodied directly in hardware, in a software module executed by a processor,
or in a combination of the two. A software module may reside in RAM memory, flash
memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable
disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary
storage medium is coupled to the processor such that the processor can read information
from, and write information to, the storage medium. In the alternative, the storage
medium may be integral to the processor. The processor and the storage medium may
reside in an ASIC.
[0039] Techniques and technologies may be described herein in terms of functional and/or
logical block components, and with reference to symbolic representations of operations,
processing tasks, and functions that may be performed by various computing components
or devices. Such operations, tasks, and functions are sometimes referred to as being
computer-executed, computerized, software-implemented, or computer-implemented. In
practice, one or more processor devices can carry out the described operations, tasks,
and functions by manipulating electrical signals representing data bits at memory
locations in the system memory, as well as other processing of signals. The memory
locations where data bits are maintained are physical locations that have particular
electrical, magnetic, optical, or organic properties corresponding to the data bits.
It should be appreciated that the various block components shown in the figures may
be realized by any number of hardware, software, and/or firmware components configured
to perform the specified functions. For example, an embodiment of a system or a component
may employ various integrated circuit components, e.g., memory elements, digital signal
processing elements, logic elements, look-up tables, or the like, which may carry
out a variety of functions under the control of one or more microprocessors or other
control devices.
[0040] When implemented in software or firmware, various elements of the systems described
herein are essentially the code segments or instructions that perform the various
tasks. The program or code segments can be stored in a processor-readable medium or
transmitted by a computer data signal embodied in a carrier wave over a transmission
medium or communication path. The "computer-readable medium", "processor-readable
medium", or "machine-readable medium" may include any medium that can store or transfer
information. Examples of the processor-readable medium include an electronic circuit,
a semiconductor memory device, a ROM, a flash memory, an erasable ROM (EROM), a floppy
diskette, a CD-ROM, an optical disk, a hard disk, a fiber optic medium, a radio frequency
(RF) link, or the like. The computer data signal may include any signal that can propagate
over a transmission medium such as electronic network channels, optical fibers, air,
electromagnetic paths, or RF links. The code segments may be downloaded via computer
networks such as the Internet, an intranet, a LAN, or the like.
[0041] Some of the functional units described in this specification have been referred to
as "modules" in order to more particularly emphasize their implementation independence.
For example, functionality referred to herein as a module may be implemented wholly,
or partially, as a hardware circuit comprising custom VLSI circuits or gate arrays,
off-the-shelf semiconductors such as logic chips, transistors, or other discrete components.
A module may also be implemented in programmable hardware devices such as field programmable
gate arrays, programmable array logic, programmable logic devices, or the like. Modules
may also be implemented in software for execution by various types of processors.
An identified module of executable code may, for instance, comprise one or more physical
or logical modules of computer instructions that may, for instance, be organized as
an object, procedure, or function. Nevertheless, the executables of an identified
module need not be physically located together, but may comprise disparate instructions
stored in different locations that, when joined logically together, comprise the module
and achieve the stated purpose for the module. Indeed, a module of executable code
may be a single instruction, or many instructions, and may even be distributed over
several different code segments, among different programs, and across several memory
devices. Similarly, operational data may be embodied in any suitable form and organized
within any suitable type of data structure. The operational data may be collected
as a single data set, or may be distributed over different locations including over
different storage devices, and may exist, at least partially, merely as electronic
signals on a system or network.
[0042] In this document, relational terms such as first and second, and the like may be
used solely to distinguish one entity or action from another entity or action without
necessarily requiring or implying any actual such relationship or order between such
entities or actions. Numerical ordinals such as "first," "second," "third," etc. simply
denote different singles of a plurality and do not imply any order or sequence unless
specifically defined by the claim language. The sequence of the text in any of the
claims does not imply that process steps must be performed in a temporal or logical
order according to such sequence unless it is specifically defined by the language
of the claim. The process steps may be interchanged in any order without departing
from the scope of the invention as long as such an interchange does not contradict
the claim language and is not logically nonsensical.
[0043] Furthermore, depending on the context, words such as "connect" or "coupled to" used
in describing a relationship between different elements do not imply that a direct
physical connection must be made between these elements. For example, two elements
may be connected to each other physically, electronically, logically, or in any other
manner, through one or more additional elements.
[0044] As used herein, the term "axial" refers to a direction that is generally parallel
to or coincident with an axis of rotation, axis of symmetry, or centerline of a component
or components. For example, in a cylinder or disc with a centerline and generally
circular ends or opposing faces, the "axial" direction may refer to the direction
that generally extends in parallel to the centerline between the opposite ends or
faces. In certain instances, the term "axial" may be utilized with respect to components
that are not cylindrical (or otherwise radially symmetric). For example, the "axial"
direction for a rectangular housing containing a rotating shaft may be viewed as a
direction that is generally parallel to or coincident with the rotational axis of
the shaft. Furthermore, the term "radially" as used herein may refer to a direction
or a relationship of components with respect to a line extending outward from a shared
centerline, axis, or similar reference, for example in a plane of a cylinder or disc
that is perpendicular to the centerline or axis. In certain instances, components
may be viewed as "radially" aligned even though one or both of the components may
not be cylindrical (or otherwise radially symmetric). Furthermore, the terms "axial"
and "radial" (and any derivatives) may encompass directional relationships that are
other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions,
provided the relationship is predominantly in the respective nominal axial or radial
direction. As used herein, the term "substantially" denotes within 5% to account for
manufacturing tolerances. Also, as used herein, the term "about" denotes within 5%
to account for manufacturing tolerances.
[0045] While at least one exemplary embodiment has been presented in the foregoing detailed
description of the invention, it should be appreciated that a vast number of variations
exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments
are only examples, and are not intended to limit the scope, applicability, or configuration
of the invention in any way. Rather, the foregoing detailed description will provide
those skilled in the art with a convenient road map for implementing an exemplary
embodiment of the invention. It being understood that various changes may be made
in the function and arrangement of elements described in an exemplary embodiment without
departing from the scope of the invention as set forth in the appended claims.