U.S. patent application number 12/539438 was filed with the patent office on 2011-02-17 for automated take off control system and method.
This patent application is currently assigned to Honeywell International Inc.. Invention is credited to Scot Griffith, Kent Stange.
Application Number | 20110040431 12/539438 |
Document ID | / |
Family ID | 43589069 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110040431 |
Kind Code |
A1 |
Griffith; Scot ; et
al. |
February 17, 2011 |
AUTOMATED TAKE OFF CONTROL SYSTEM AND METHOD
Abstract
Methods and systems for operating an avionics system on-board an
aircraft are provided. In one embodiment, an indication of a
position of the aircraft is received, the position is calculated
based on the indication, the calculated position is compared to
navigational information to establish the suitability of the
calculated position for initiating a take off roll path, and an
indication of the results is generated. In another embodiment, a
desired angle of attack is determined, and during the automated
take off, the pitch is adjusted such that an actual angle of attack
is substantially the same as the desired angle of attack. In a
further embodiment, data associated with a take off roll is
received, one or more v-speeds of the aircraft associated with the
take off roll are calculated, and during the take off roll, the
aircraft is controlled based on the one or more calculated
v-speeds.
Inventors: |
Griffith; Scot; (Glendale,
AZ) ; Stange; Kent; (Phoenix, AZ) |
Correspondence
Address: |
HONEYWELL/IFL;Patent Services
101 Columbia Road, P.O.Box 2245
Morristown
NJ
07962-2245
US
|
Assignee: |
Honeywell International
Inc.
Morristown
NJ
|
Family ID: |
43589069 |
Appl. No.: |
12/539438 |
Filed: |
August 11, 2009 |
Current U.S.
Class: |
701/15 |
Current CPC
Class: |
G05D 1/0661 20130101;
B64C 19/00 20130101 |
Class at
Publication: |
701/15 |
International
Class: |
G05D 1/00 20060101
G05D001/00; G01C 21/00 20060101 G01C021/00 |
Claims
1. A method for operating an avionics system on-board an aircraft
comprising: receiving one or more indications of a position of the
aircraft; calculating the position of the aircraft based on the one
or more indications of the position of the aircraft; comparing the
position to navigational information stored in the avionics system
to establish the suitability of the position for initiating a take
off roll path; and generating an indication of the suitability of
the position for initiating a take off roll path.
2. The method of claim 1, wherein the one or more indications of
the position of the aircraft comprises an estimated position of the
aircraft based on Global Positioning Satellite (GPS) information,
an estimated position of the aircraft based on information
generated by an inertial navigation system (INS) on-board the
aircraft, and a signal generated in response to input entered by a
user into a user input device on-board the aircraft, the input
being indicative of an estimated position of the aircraft based on
the user's observations, or a combination thereof
3. The method of claim 2, wherein the comparing of the position to
the navigational information comprises determining if the
calculated position of the aircraft is within a predetermined
distance from an ideal position to initiate the take off roll path
at a first end of a runway.
4. The method of claim 3, further comprising determining a
centerline intersection at a second end of the runway based the
navigational information in the avionics system.
5. The method of claim 4, further comprising determining a take off
roll path based on the ideal position to initiate the take off roll
path and the centerline intersection at a second end of the
runway.
6. The method of claim 5, further comprising automatically
performing a take off with the aircraft based on the determined
take off roll path.
7. The method of claim 6, further comprising: monitoring the
calculated position of the aircraft during the take off in
real-time; and navigating the aircraft based on the monitoring of
the calculated position of the aircraft during the take and the
determined take off roll path.
8. A method for controlling an aircraft during an automated take
off, the method comprising: determining a desired angle of attack
for the aircraft; and during the automated take off, adjusting the
pitch of the aircraft such that an actual angle of attack of the
aircraft is substantially the same as the desired angle of attack
of the aircraft.
9. The method of claim 8, wherein the determining of the desired
angle of attack for the aircraft is based on a desired performance
of the aircraft during take off
10. The method of claim 8, wherein the determining of the desired
angle of attack for the aircraft comprises continuously computing
the desired angle of attack in real-time.
11. The method of claim 10, further comprising preventing the pitch
of the aircraft from exceeding a predetermined threshold.
12. The method of claim 8, further comprising: receiving one or
more indications of a position of the aircraft; calculating the
position of the aircraft based on the one or more indications of
the position of the aircraft; comparing the position to
navigational information stored in the avionics system to establish
the suitability of the position for initiating a take off roll
path; and generating an indication of the suitability of the
position for initiating a take off roll path.
13. The method of claim 12, wherein the one or more indications of
the position of the aircraft comprises an estimated position of the
aircraft based on Global Positioning Satellite (GPS) information,
an estimated position of the aircraft based on information
generated by an inertial navigation system (INS) on-board the
aircraft, and a signal generated in response to input entered by a
user into a user input device on-board the aircraft, the input
being indicative of an estimated position of the aircraft based on
the user's observations, or a combination thereof
14. A method for controlling an aircraft during an automated take
off, the method comprising: receiving data associated with the
aircraft during a take off roll; calculating one or more v-speeds
of the aircraft associated with the take off roll; and during the
take off roll, controlling the aircraft based on the one or more
calculated v-speeds.
15. The method of claim 14, wherein at least some of the data is
received during the take off roll.
16. The method of claim 15, wherein the received data comprises
real-time aircraft performance data, environmental conditions,
geographical data, or a combination thereof.
17. The method of claim 16, wherein calculating of the one or more
v-speeds comprises continuously computing the one of more v-speeds
in real-time.
18. The method of claim 16, further comprising aborting the take
off if any of the received data exceeds a predetermined
threshold.
19. The method of claim 16, further comprising receiving one or
more estimated v-speeds from a user input device on-board the
aircraft.
20. The method of claim 19, further comprising: comparing the one
or more calculated v-speeds to the one or more estimated v-speeds;
and generating an indication if a difference between the one or
more calculated v-speeds and the one or more estimated v-speeds is
greater than a predetermined threshold.
Description
TECHNICAL FIELD
[0001] The present invention generally relates to avionics systems,
and more particularly relates to avionics systems with automated
take off capabilities.
BACKGROUND
[0002] Despite of the ever increasing sophistication of avionics
systems, take off remains one of the most complicated and difficult
functions required by aircraft personnel. In order to safely
perform a take off procedure, personnel must confirm that the
aircraft is property configured, appropriately respond to
unpredicted changes in performance, be aware of obstacles on the
runway regardless of the weather conditions, and properly control
the various axes of the aircraft, including the pitch of the
aircraft so as to prevent the tail of the aircraft from touching
the ground.
[0003] Accordingly, it is desirable to provide a system and method
for at least partially automating some of the procedures of
aircraft take off to improve safety and reduce training costs.
Furthermore, other desirable features and characteristics of the
present invention will become apparent from the subsequent detailed
description and the appended claims, taken in conjunction with the
accompanying drawings and the foregoing technical field and
background.
BRIEF SUMMARY
[0004] A method for operating an avionics system on-board an
aircraft is provided. One or more indications of a position of the
aircraft is received. The position of the aircraft is calculated
based on the one or more indications of the position of the
aircraft. The position is compared to navigational information
stored in the avionics system to establish the suitability of the
position for initiating a take off roll path. An indication of the
comparison of the position to the navigational information is
generated.
[0005] In another embodiment, a method for controlling an aircraft
during an automated take off is provided. A desired angle of attack
for the aircraft is determined During the automated take off, the
pitch of the aircraft is adjusted such that an actual angle of
attack of the aircraft is substantially the same as the desired
angle of attack of the aircraft.
[0006] In a further embodiment, a method for controlling an
aircraft during an automated take off is provided. Data associated
with the aircraft during a take off roll is received. One or more
v-speeds of the aircraft associated with the take off roll are
calculated. During the take off roll, the aircraft is controlled
based on the one or more calculated v-speeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and
[0008] FIG. 1 is a block diagram schematically illustrating an
vehicle according to one embodiment of the present invention;
[0009] FIG. 2 is a block diagram of a navigation and control system
within the vehicle of FIG. 1; and
[0010] FIG. 3 is a plan view representing the position of the
vehicle of FIG. 1 relative to a runway.
DETAILED DESCRIPTION
[0011] 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. Furthermore, there is no
intention to be bound by any expressed or implied theory presented
in the preceding technical field, background, and brief summary or
the following detailed description. It should also be noted that
FIGS. 1-3 are merely illustrative and may not be drawn to
scale.
[0012] Systems and methods in accordance with various aspects of
the present invention provide an improved signal processing
schemes. In this regard, the present invention may be described
herein in terms of functional block components and various
processing steps. It should be appreciated that such functional
blocks may be realized by any number of hardware, firmware, and/or
software components configured to perform the specified
functions.
[0013] For example, the present invention may employ various
integrated circuit components, such as memory elements, digital
signal processing elements, look-up tables, databases, and the
like, which may carry out a variety of functions, some using
continuous, real-time computing, under the control of one or more
microprocessors or other control devices. Such general techniques
and components that are known to those skilled in the art are not
described in detail herein.
[0014] FIG. 1 to FIG. 3 illustrate systems and methods for
operating an avionics system to enable the automated take of
aircraft. In one embodiment, one or more indications of a position
(and/or orientation/heading) of the aircraft (e.g., from a Global
Positioning Satellite (GPS) system or an inertial navigations
system) is received. The position of the aircraft is calculated
based on the one or more indications of the position of the
aircraft. The calculated position is compared to navigational
information stored in the avionics system to establish whether the
calculated position is suitable for initiating a take off roll path
(e.g., whether the calculated position is within a predetermined
distance of an ideal position for initiating a take off roll). An
indication of the comparison of the calculated position to the
navigational information is generated (e.g., an audible or visual
signal) and provided to a user (e.g., the pilot).
[0015] FIG. 1 schematically illustrates a vehicle 10, such as an
aircraft, in which the method and system described below may be
implemented, according to one embodiment of the present invention.
The vehicle 10 may be, in one embodiment, any one of a number of
different types of aircraft such as, for example, a private
propeller or jet engine driven airplane, a commercial jet liner, or
a helicopter. In the depicted embodiment, the aircraft 10 includes
a flight deck 12 (or cockpit) and an avionics/flight system 14.
Although not specifically illustrated, it should be understood that
the vehicle aircraft also includes a frame or body to which the
flight deck 12 and the avionics/flight system 14 are connected, as
is commonly understood.
[0016] As shown in FIG. 1, the flight deck 12 includes a user
interface 16, display devices 18 and 20 (e.g., a display screen for
a flight management system (FMS) and a primary flight display
(PFD)), a communications radio 22, a navigational radio 24, and an
audio device 26. The user interface 16 is configured to receive
manual input from a user 28 and, in response to the user input,
supply command signals to the avionics/flight system 14. It should
be understood that the user 28 may refer to various types of
personnel, such as a pilot or crewperson or a technician or other
maintenance engineer.
[0017] The user interface 16 may be any one, or combination, of
various known flight control devices and user interface/text entry
devices including, but not limited to, a cursor control device
(CCD), such as a mouse, a trackball, or joystick, and/or a
keyboard, one or more buttons, switches, or knobs. As such, the
user interface 16 may include a text entry device comprising any
device suitable to accept alphanumeric character input from user 28
and convert that input to alphanumeric text on the displays 18 and
20. In the depicted embodiment, the user interface 16 includes a
CCD 30 and a keyboard 32. The user 28 uses the CCD 30 to, among
other things, move a cursor symbol on the display devices 18 and
20, and may use the keyboard 32 to, among other things, input
textual data.
[0018] Still referring to FIG. 1, the display devices 18 and 20 are
used to display various images and data, in graphic, iconic, and/or
textual formats, and to supply visual feedback to the user 28 in
response to user input commands supplied by the user 28 to the user
interface 16. One or more of the displays 18 and 20 may further be
a control display unit (CDU), a multifunction control display unit
(MCDU), or a graphical display. It will be appreciated that the
display devices 18 and 20 may each be implemented using any one of
numerous known displays suitable for rendering image and/or text
data in a format viewable by the user 28, such as a cathode ray
tube (CRT) displays, a LCD (liquid crystal display), a TFT (thin
film transistor) displays, or a heads up display (HUD)
projection.
[0019] The communication radio 22 is used, as is commonly
understood, to communicate with entities outside the aircraft 10,
such as air-traffic controllers and pilots of other aircraft. The
navigational radio 24 is used to receive from outside sources and
communicate to the user various types of information regarding the
location of the vehicle, such as Global Positioning Satellite (GPS)
system and Automatic Direction Finder (ADF) (as described below).
The audio device 26 is, in one embodiment, an audio speaker mounted
within the flight deck 12.
[0020] The avionics/flight system 14 includes a navigation and
control system (or subsystem) 34, an environmental control system
(ECS) 36, a cabin pressurization control system (CPCS) 38, an
auxiliary power unit (APU) control system 40, an anti-skid
brake-by-wire system 42, a nose wheel steering system 44, a landing
gear control system 46, an engine thrust reverse control system 48,
various other engine control systems 50, a plurality of sensors 52,
one or more terrain databases 54, one or more navigation databases
56, and a processor 58. The various components of the
avionics/flight system 14 are in operable communication via sensor
inputs (e.g., analog sensor inputs) 59 (or a data or avionics
bus).
[0021] FIG. 2 illustrates the navigation and control system 34 in
greater detail. The navigation and control system 34, in the
depicted embodiment, includes a flight management system (FMS) 60,
an inertial navigation system (INS) 62, an autopilot or automated
guidance system 64, multiple flight control surfaces (e.g.,
ailerons, elevators, and a rudder) 66, an Air Data Computer (ADC)
68, an altimeter 70, an Air Data System (ADS) 72, a Global
Positioning System (GPS) module 74, an automatic direction finder
(ADF) 76, a compass 78, at least one engine 80, and gear (i.e.,
landing gear) 82.
[0022] Of particular interest in FIG. 2, although not shown in
detail, the INS 62 includes multiple inertial sensors, such as
accelerometers and gyroscopes (e.g., ring laser gyros), that are
configured to calculate, and detect changes in, the position,
orientation, and velocity of the aircraft 10, as is commonly
understood.
[0023] Referring again to FIG. 1, as is commonly understood, the
ECS 36 and the CPCS 38 may control the air supply and temperature
control, as well as the cabin pressurization, for the flight deck
12 (and the passenger compartment) of the aircraft 10. The ECS 36
may also control avionics cooling, smoke detection, and fire
suppression systems.
[0024] The APU control system 40 manages the operation of an APU
(not shown), which provides power to various systems of the
aircraft 10 (e.g., other than propulsion). The anti-skid
brake-by-wire system 42 controls the wheel brakes (not shown)
during take off and landing so as to prevent the wheel from losing
traction with the ground. The nose wheel steering system 44 and the
landing gear control system 46 control (e.g., in combination with
input from the user 28) the landing gear to provide both direction
control of the aircraft 10 when on the ground and raise and lower
the landing gear during take off and landing approach.
[0025] The engine thrust reverse control system 48 and other engine
control systems 50 manage the operation of the engines during all
stages of operation (e.g., take-off, in flight, and during
landing). Although not illustrated, the sensors 52 may include, for
example, a barometric pressure sensor, a thermometer, a wind speed
sensor, and an angle of attack sensor, as is commonly
understood.
[0026] The terrain databases 54 include various types of data
representative of the terrain over which the aircraft 10 may fly.
The navigation (and/or avionics) databases 56 include various types
of data required by the system, for example, state of the aircraft
data, flight plan data, data related to airways, waypoints and
associated procedures (including arrival and approach procedures)
navigational aids (Navaid), symbol textures, navigational data,
obstructions, font textures, taxi registration, special use
airspace, political boundaries, communication frequencies (en route
and airports), approach info, and the like.
[0027] The processor (or processing system) 58 may be any one of
numerous known general-purpose microprocessors or an application
specific processor that operates in response to program
instructions. In the depicted embodiment, the processor 58 includes
on-board random access memory (RAM) 84 and on-board read only
memory (ROM) 86. The program instructions that control the
processor 58 may be stored in either or both the RAM 84 and the ROM
86 (or another computer-readable medium) and may include
instructions for carrying out the processes described below. For
example, the operating system software may be stored in the ROM 86,
whereas various operating mode software routines and various
operational parameters may be stored in the RAM 84. It will be
appreciated that this is merely exemplary of one scheme for storing
operating system software and software routines, and that various
other storage schemes may be implemented. It will also be
appreciated that the processor 58 may be implemented using various
other circuits, not just a programmable processor. For example,
digital logic circuits and analog signal processing circuits could
also be used.
[0028] It should also be noted that the aircraft 10 is merely
exemplary and could be implemented without one or more of the
depicted components, systems, and data sources. It will
additionally be appreciated that the aircraft 10, the flight deck,
and/or the avionics/flight system 14 could be implemented with one
or more additional components, systems, or data sources, some of
which are mentioned below.
[0029] According to one aspect of the present invention,
indications (or indicators) of a position (and/or orientation) of
the aircraft 10 are received from one ore more sources, such as the
GPS system 74, the INS 62, and/or the user interface 16. The
position of the aircraft 10 is calculated based on the received
indications. The position (or the calculated position) is compared
to navigational information stored in, for example, the navigation
databases 56 to determine whether the calculated position is
suitable for initiating a take off roll path. That is, it is
determined whether the calculated position is within a
predetermined distance of an ideal position (i.e., at an end of a
runway) for initiating a take off roll. An indication of the
comparison of the calculated position to the navigational
information is generated and provided to a user (e.g., the
pilot).
[0030] If the calculated position is determined to be suitable for
initiating a take off roll, A take off roll path may then be
generated from the ideal initiation positions and the geographical
runway and terrain information from the databases 54 and 65. This
path would an ideal path for the take off roll through lift off and
climb to a predetermined height or abort and deceleration to safe
speed. The processor 58 may then control the aircraft 10 to
automatically take off, while monitoring (e.g., using the INS 62)
the actual position and performance of the aircraft in relation to
the generated take off roll path. If the aircraft 10 deviates from
the take off roll path and/or ideal performance, the system may
automatically correct the operation of the aircraft 10 (e.g., yaw
and/or pitch control) and/or abort the take off altogether.
[0031] FIG. 3 illustrates the aircraft 10 in relation to a runway
100 (not drawn to scale). In one embodiment, the aircraft 10 is
taxied (e.g., manually) to a first end 102 of the runway 100. The
system (e.g., the processor 58) then receives various indications
of the position of the aircraft 10. Examples of position indicators
include, but are not limited to, coordinates from the GPS system
74, an estimated position and orientation from the INS 62, an
estimated position determined using radio navigation, a heading of
the aircraft 10 determined using the compass 78, and a position of
the aircraft 10 relative to the center of the runway 100 determined
using the localizer radio guide associated with the runway 100, as
is commonly understood. As another example of a position indicator,
the user 28 may manually enter a confirmation of the position of
the aircraft 10 using the user interface 16 when he or she believes
the aircraft 10 is appropriately positioned, based on, for example,
visual observations (i.e., made by the user 28 and/or ground
personnel).
[0032] Based on the received indications, the system then
calculates (or determines) the "actual" position 106 of the
aircraft 10. The calculation of the position 106 of the aircraft 10
may weight each of the indications based on the assumed reliability
of each (e.g., the GPS coordinates may be more heavily weighted
than the visual confirmation made by the user 28).
[0033] The calculated position 106 is then compared to navigational
data stored in the navigation database 56. In particular, the
calculated position 106 may be compared to an ideal take off roll
initiation position 108 of the runway 100 nearest runway (i.e., a
position at the center of the runway 100 near the first end 102).
As is commonly understood, the navigation database 56 includes
navigational coordinates corresponding to various portions of
runways, as well as other characteristics of the runways, such as
slope. The comparison the calculated position 106 to the ideal take
off roll initiation position 108 may result in a lateral (or yaw)
offset 110 (i.e., a distance between the calculated position 106
and the ideal take off roll initiation position 108).
[0034] If the lateral offset 110 is above a predetermined threshold
(e.g., 3 meters), the system may generate an indication (e.g.,
using the audio device 26 and/or one of the display devices 18 and
20) to alert the user 28 that the aircraft 10 is not in a position
suitable to initiate a take off roll. The system may also
automatically override any attempts to take off from the calculated
position (e.g., by cutting or reducing power to the engine 80).
[0035] If the lateral offset 110 is below the predetermined
threshold, the system may provide an appropriate indication to the
user 28 before continuing preparations for take off The system then
determines the centerline intersection point 112 near the second
end 104 of the runway 100 (i.e., and/or a "lift off" position at
the center of the runway 100 near the second end 104), by accessing
the navigation database 56. Using the positions 108 and 112 a take
off roll path 114 is then calculated.
[0036] As shown in Figure. 3, the take off roll path 114 may
essentially correspond to a centerline of the runway 100. However,
in some embodiments, the take off roll path 114 may also include
information concerning the appropriate speeds of the aircraft 10 at
different locations along the path 114 during take off, as well as
suitable rotation rates (i.e., in pitch) depending on the speed and
weight of the aircraft entered into the FMS 60.
[0037] Additionally, the system may confirm that the aircraft 10 is
suitably configured for take off (e.g., proper flap settings).
[0038] During take off, the system commands the servos associated
with various control systems (e.g., the engine 80, the flight
control surfaces 66, the nose wheel steering subsystem 44, etc.)
such that the take off is at least partially automated to follow
the calculated take off roll path 114. For example, as the aircraft
10 accelerates towards the second end 104 of the runway 100, the
yaw (and nose wheel steering) may be automatically controlled to
navigate the aircraft 10 along the calculated take off roll path
114. In the example shown in FIG. 3, this may include steering the
aircraft 10 slightly starboard at the initiation of the take off
roll to overcome the lateral offset 110.
[0039] In one embodiment, the system also monitors the position and
performance of the aircraft 10 during take off and, in real-time,
compares it to the calculated take off roll path 114. If deviations
from the take off roll path 114 are detected, such as by using the
INS 62 and/or the compass 78, corrections may be made to keep the
aircraft 10 on the calculated take off roll path 114. That is, the
system operates in a "closed-loop" fashion to keep the aircraft on
the take off roll path 114 as much as possible, including
maintaining appropriate speeds and rotation rates.
[0040] Additionally, the system may abort take off if certain
conditions are detected (and/or particular thresholds are
exceeded). Examples of such conditions include, but are not limited
to, insufficient speed and/or acceleration, lack of runway length
remaining, extreme deviation from the take off roll path 114, and
poor engine performance. Also, the aircraft 10 may utilize various
subsystems (e.g., a Runway Awareness and Advisory System (RAAS), as
is commonly understood) and sensors (e.g., infra-red or
electro-optical cameras) to detect the presence of unauthorized
objects on the runway 100, such as other aircraft, and suitably
abort the take off if such objects are detected.
[0041] Real-time results of the monitoring of the aircraft
performance may also be display to the user 28 via one of the
display devices 18 and 20 (e.g., a HUD) in such a way as to aid the
user 28 if he or she determines that manual intervention is
required to keep the aircraft 10 on the take off roll path 114. For
example, a visual indicator of the lateral position of the aircraft
10 relative to the take off roll path 114 may be displayed to alert
the user 28 of poor performance.
[0042] According to another aspect of the present invention, a
method for controlling an aircraft during an automated take off is
provided, in which the aircraft is controlled to a specified angle
of attack, as opposed to simply a pitch angle. In such an
embodiment, a desired angle of attack for the aircraft is
determined (e.g., in real-time). During the automated take off, the
pitch of the aircraft is adjusted such that an actual angle of
attack of the aircraft is substantially the same as the desired
angle of attack of the aircraft (e.g., the actual angle of attack
tracks the desired angle of attack in real-time).
[0043] As will be appreciated by one skilled in the art, the angle
of attack refers to the angle between a center, chord line of an
airfoil (e.g., a wing) and the relative direction of motion of the
air mass (and/or the wind) and is related to the ratio of the
amount of lift created and drag generated by the airfoil. As such,
the desired angle of attack may be determined by first selecting a
particular v-speed, or velocity-speed, as a desired performance
characteristic of the aircraft 10. As is commonly understood,
v-speeds are typically set by performance criteria required by the
aviation regulatory authorities for specific types of aircraft.
Examples include the speed that allows for the maximum rate of
climb (V.sub.Y), the speed that allows for the highest angle of
climb (V.sub.X), the speed at which the aircraft 10 is rotated
(i.e., pitched) during take off (V.sub.R), and the maximum speed at
which the take off may be aborted (V.sub.1).
[0044] In one embodiment, an angle of attack is determined based
on, for example, desired performance During take off, the system
monitors the angle of attack (e.g., using a signal generated by the
angle of attack sensor) and controls the pitch of the aircraft
(e.g., using the elevators and pitch trim devices) such that the
actual angle of attack obtains, or nearly obtains, the desired
magnitude (i.e., the desired angle of attack). Limits may be
imposed on the pitch of the aircraft such that the aircraft is not
operated in an undesirable manner (e.g., pitched at 90.degree. or
in a way that the tail might tail strike). This method may be used
in conjunction with the other methods described above.
[0045] According to a further aspect of the present invention, a
method for controlling an aircraft during an automated take off is
provided in which v-speeds (e.g., those described above) are
automatically calculated and used to control the aircraft. In such
an embodiment, data associated with the aircraft during a take off
roll is received. One or more v-speeds of the aircraft associated
with the take off roll are calculated. During the take off roll,
the aircraft is controlled based on the one or more calculated
v-speeds.
[0046] In one embodiment, the particular v-speeds are automatically
calculated from, for example, information entered into the system
by a user (e.g., estimated weight of the aircraft), environmental
conditions (e.g., temperature, relative humidity, and barometric
pressure) as detected by various sensors, and geographical data
about the particular runway in use (e.g., the presence of terrain
features and/or restricted airspace). The calculated v-speeds are
then used during the automated take off procedure. The calculated
v-speeds may be updated due to detected real-time aircraft
performance, and used to override estimated v-speeds entered by the
user. For example, the user may estimate that V.sub.R is 140 mph.
However, the system may determine that the actual weight of the
aircraft is greater than that entered (e.g., by slow acceleration),
re-calculate V.sub.R to be 160 mph, and delay rotation until the
aircraft has reached such a speed during take off roll in order to
prevent the tail from touching the ground (i.e., a tail strike).
The system may then provide an indication to the pilot (e.g., using
the display devices 18 and 20) that the estimated V.sub.R was
incorrect and overridden during take off. This method may be used
in conjunction with the other methods described above, and as such,
may be implemented in real-time and used to control the aircraft
during automated take off.
[0047] The method and system described above may offer many
advantages over conventional avionics system. One advantage is that
the required minimum visual range may be reduced. As a result, the
likelihood of take off being delayed because of weather may be
reduced. Another advantage is that because of the increased
automation of take off procedures, the costs involved with properly
training personnel may be reduced. Further, the likelihood that the
aircraft will experience any runway excursions and tail strikes is
reduced.
[0048] While at least one exemplary embodiment has been presented
in the foregoing detailed description, 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 the
exemplary embodiment or exemplary embodiments. It should be
understood that various changes can be made in the function and
arrangement of elements without departing from the scope of the
invention as set forth in the appended claims and the legal
equivalents thereof.
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