U.S. patent application number 10/998408 was filed with the patent office on 2008-12-04 for terrain augmented display symbology.
This patent application is currently assigned to Honeywell International Inc.. Invention is credited to Gang He.
Application Number | 20080300735 10/998408 |
Document ID | / |
Family ID | 40089157 |
Filed Date | 2008-12-04 |
United States Patent
Application |
20080300735 |
Kind Code |
A1 |
He; Gang |
December 4, 2008 |
TERRAIN AUGMENTED DISPLAY SYMBOLOGY
Abstract
Terrain augmented display symbology improves a pilot's spatial
awareness during aircraft approach and landing. The symbology
includes a terrain-tracing, three-dimensional centerline that
provides a visual cue of terrain elevations along an approach
course to a runway. Additionally, the symbology includes
terrain-tracing, three-dimensional lateral deviation marks
representing deviations from the centerline. The symbology also
includes an aircraft symbol shaped like an airplane and pointing
towards the direction of travel. The pilot may be able to quickly
interpret the terrain augmented display symbology and take actions
based on the surrounding terrain elevation.
Inventors: |
He; Gang; (Morristown,
NJ) |
Correspondence
Address: |
HONEYWELL INTERNATIONAL INC.
101 COLUMBIA ROAD, P O BOX 2245
MORRISTOWN
NJ
07962-2245
US
|
Assignee: |
Honeywell International
Inc.
Morristown
NJ
|
Family ID: |
40089157 |
Appl. No.: |
10/998408 |
Filed: |
November 29, 2004 |
Current U.S.
Class: |
701/3 |
Current CPC
Class: |
G08G 5/0021 20130101;
G01C 23/00 20130101; G08G 5/025 20130101 |
Class at
Publication: |
701/3 |
International
Class: |
G01C 23/00 20060101
G01C023/00 |
Claims
1. A navigation display system, comprising: a graphics processor
for receiving data and providing an output including symbology that
is displayed on a screen, wherein the symbology includes a
terrain-tracing centerline providing a visual cue of terrain
elevations along an approach course to a runway.
2. The system of claim 1, wherein the screen is a component of a
head-up display.
3. The system of claim 1, wherein the screen is a component of a
heads-down display.
4. The system of claim 1, further including a terrain database.
5. The system of claim 4, wherein the centerline is generated by
computing lateral line coordinates along the approach course to a
runway endpoint and obtaining corresponding elevation data from the
terrain database.
6. The system of claim 1, wherein the symbology further includes at
least two terrain-tracing lateral deviation marks.
7. The system of claim 6, wherein the lateral deviation marks point
towards an end of the runway.
8. The system of claim 6, wherein the lateral deviation marks
represent a deviation from the centerline.
9. The system of claim 6, wherein the lateral deviation marks are
centered about the centerline.
10. The system of claim 1, wherein the symbology further includes
an aircraft symbol shaped like an airplane.
11. The system of claim 10, wherein the aircraft symbol points
towards an end of the runway.
12. The system of claim 10, wherein lateral deviation marks are
centered about the aircraft symbol.
13. A navigation display system, comprising in combination: a
screen for displaying data; and a graphics processor for receiving
data and providing an output including symbology that is displayed
on the screen, wherein the symbology includes a terrain-tracing
centerline providing a visual cue of terrain elevations along an
approach course to a runway, at least two terrain-tracing lateral
deviation marks representing deviations from the centerline, and an
aircraft symbol shaped like an airplane.
14. A method for providing terrain augmented conformal lateral
deviation display symbology, comprising in combination: determining
an approach course to a runway; generating a terrain-tracing
centerline symbol along the approach course; and displaying the
centerline symbol on a screen, wherein the centerline symbol
provides a visual cue of terrain elevations along the approach
course to the runway.
15. The method of claim 14, wherein generating the terrain-tracing
centerline symbol includes computing lateral line coordinates along
the approach course and retrieving terrain elevation data
corresponding to the coordinates.
16. The method of claim 14, further including generating an
aircraft symbol.
17. The method of claim 16, further including displaying the
aircraft symbol on the screen providing aircraft position
information.
18. The method of claim 17, wherein the aircraft symbol further
provides a direction of travel.
19. The method of claim 16, further including generating at least
two lateral deviation marks.
20. The method of claim 19, wherein generating the lateral
deviation marks includes computing terrain-tracing projection lines
at a number of fixed angles matching an emission beam pattern from
a runway beacon.
21. The method of claim 19, further including displaying the
lateral deviation marks on the screen so that the lateral deviation
marks are centered about the centerline symbol.
22. The method of claim 19, further including displaying the
lateral deviation marks on the screen so that the lateral deviation
marks are centered about the aircraft symbol.
23. The method of claim 14, wherein the centerline symbol is
displayed on the screen if a runway is selected and an aircraft's
distance to the runway is less than a threshold value.
24. The method of claim 14, wherein the screen is a component of a
head-up display.
25. The method of claim 14, wherein the screen is a component of a
heads-down display.
Description
FIELD
[0001] The present invention relates generally to display
symbology, and more particularly, relates to terrain augmented
display symbology.
BACKGROUND
[0002] A pilot uses flight instruments and associated displays to
navigate an aircraft. The easier it is for the pilot to obtain and
understand the information provided by these instruments and
displays, the more likely that the pilot will be able to
successfully navigate the aircraft. This is especially true during
approach and landing on a runway.
[0003] Currently, instrument landing systems (ILS), microwave
landing systems (MLS), or satellite landing systems (SLS) are used
to guide aircraft during landing. These systems typically use a
deviation bar on a horizontal indicator to indicate lateral
deviation from the approach course and a glide scope indicator to
indicate vertical deviation from the glide scope. The deviation bar
and the glide scope indicator provide flight path deviation
information to the pilot, allowing the pilot to make flight path
corrections while landing.
[0004] Because looking at the horizontal indicator causes the pilot
to look away from the cockpit window, some aircraft have
incorporated a head-up display. The head-up display projects
symbology representing the deviation bar and glide scope indicator
onto a screen integrated into the cockpit window, so that the pilot
can simultaneously view both the symbology and conditions outside
the cockpit. This solution improves safety because the pilot can
continue to monitor the situational progress of the flight while
obtaining flight data. In addition, pilot fatigue is reduced by
reducing the number of instruments needing to be scanned.
[0005] Initially, the symbology used on the head-up display to
represent the information previously provided by the horizontal
indicator was not intuitive. The pilot had to be trained to
understand what data the symbology represented and how to interpret
the data. By making the symbology more intuitive, aircraft
navigation is simplified, pilot error and fatigue is reduced, and
safety is increased.
[0006] An improvement to symbology format is addressed in U.S. Pat.
No. 5,745,863 titled "Three Dimensional Lateral Displacement
Display Symbology Which Is Conformal To The Earth," which is
assigned to the same assignee as the present invention and is
hereby incorporated by reference in its entirety. U.S. Pat. No.
5,745,863 describes using two-dimensional lines to depict an
extended course centerline, which extends towards a vanishing point
near a horizon line on the display, and two-dimensional deviation
marks on either side of an aircraft symbol.
[0007] While U.S. Pat. No. 5,745,863 describes some improvements
regarding display symbology, additional improvements can be made.
These additional improvements may further simplify aircraft
navigation, reduce pilot error and fatigue, and increase
safety.
SUMMARY
[0008] A system and method for providing terrain augmented display
symbology is described. The symbology includes a terrain-tracing
centerline that provides a visual cue of terrain elevations along
an approach course to a runway. The symbology also includes
terrain-tracing lateral deviation marks representing deviations
from the centerline. An aircraft symbol shaped like an airplane may
also be used to indicate the direction of flight.
[0009] A graphics processor receives data from a variety of sources
including avionic systems and a terrain database. The terrain
database includes elevation data that corresponds to geographic
coordinates. The graphics processor uses the data received from the
avionics systems and the terrain database and generates the
symbology. The symbology is then displayed on a screen, such as the
screen in a head-up display or a heads-down display with synthetic
terrain image background.
[0010] These as well as other aspects and advantages will become
apparent to those of ordinary skill in the art by reading the
following detailed description, with reference where appropriate to
the accompanying drawings. Further, it is understood that this
summary is merely an example and is not intended to limit the scope
of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Presently preferred embodiments are described below in
conjunction with the appended drawing figures, wherein like
reference numerals refer to like elements in the various figures,
and wherein:
[0012] FIG. 1 is a block diagram of a flight system, according to
an example;
[0013] FIG. 2 illustrates a flight display, according to an
example;
[0014] FIG. 3 illustrates a flight display, according to another
example;
[0015] FIG. 4 illustrates a flight display, according to another
example;
[0016] FIG. 5 illustrates a flight display, according to another
example; and
[0017] FIG. 6 is a flow diagram depicting a method for providing
terrain augmented display symbology, according to an example.
DETAILED DESCRIPTION
[0018] FIG. 1 is a block diagram of a flight system 100. The flight
system 100 includes a variety of avionic systems, including an air
data computer 102, a navigation system 104, a mode panel 106, and a
radio altimeter 108. These, as well as other avionic systems, may
provide data to a graphics processor 110. For example, the air data
computer 102 may provide barometric altitude, the navigation system
104 may provide glide slope deviation, the mode panel 106 may
provide glide path angle and other runway information, and the
radio altimeter 108 may provide radio altitude to the graphics
processor 110. Additionally, the graphics processor 110 may receive
data from a variety of other sources, including a terrain database
112. The terrain database 112 includes elevation data that
corresponds to geographic coordinates.
[0019] The graphics processor 110 may generate the symbology
described herein using techniques substantially the same as prior
art symbols, such as a runway symbol. Based on the data received,
the graphics processor 110 controls what is displayed on a display
114. In a preferred embodiment, the display 114 is a heads-down or
a head-up display.
[0020] However, other displays now known or developed in the future
may be used. For example, the display 114 may be a helmet mounted
display.
[0021] In an aircraft using a head-up display, the screen of the
display 114 is incorporated into the cockpit window of an aircraft.
Thus, the pilot is able to view the symbology on the screen while
monitoring conditions outside the aircraft. In a heads-down
display, synthetic terrain images are used on a background in which
flight symbology are displayed as schematic overlays.
[0022] FIG. 2 illustrates a flight display 200. The flight display
200 includes example terrain augmented display symbology generated
by the graphics processor 110. The flight display 200 depicts a
centerline 202 ending at a runway 204. The centerline 202 is a
symbolic guide used by the pilot to adjust the aircraft's flight
path during the approach to the runway 204.
[0023] Also shown in FIG. 2 is a flight path marker 206, which is a
primary guidance cue for aircraft controls and for turning and
aligning with the runway 204. The flight path marker 206 depicts
the current position of the aircraft in relationship to the
centerline 202. FIG. 2 also depicts an aircraft symbol 208 which
may be used by the pilot to monitor aircraft roll conditions.
Additional flight information may also be depicted on the flight
display 200.
[0024] The centerline 202 is a terrain-tracing, three-dimensional
extended runway centerline. In some instances, the presence of
terrain and other sensitive areas requires an. approach course line
that differs from the runway centerline. The centerline 202 traces
the terrain surface, which provides the pilot with more guidance
than a two-dimensional. (i.e., straight line) centerline. As a
result, the pilot can more easily plan course adjustments during
approach to the runway 204 based on the terrain elevation. For
example, the pilot may adjust the course of the aircraft so as to
avoid a mountain peak upon approach to the runway 204.
[0025] The centerline 202 may be calculated using runway position
data and terrain data located in the terrain database 112. More
specifically, the centerline 202 may be generated by computing
lateral line coordinates extended from a runway end point along the
runway 204 direction or along the direction of a selected approach
course. The runway position data may be obtained from an on-board
navigation database and/or from a data link. The computed lateral
line coordinates may then be used to obtain corresponding elevation
data, which may be obtained from the terrain database 112.
[0026] FIG. 3 illustrates a flight display 300. The flight display
300 includes additional terrain augmented display symbology
generated by the graphics processor 110. The flight display 300
depicts a centerline 302 ending at a runway 304. The centerline 302
is similar to the centerline 202 depicted in FIG. 2, but located on
different terrain.
[0027] Also shown in FIG. 3 is an aircraft symbol 306 shaped like
an airplane. Additionally, terrain-tracing, three-dimensional,
lateral deviation marks 308 are depicted on the flight display 300.
While four lateral deviation marks 308 are depicted in FIG. 3, more
or less than four lateral deviation marks may be used. Both the
aircraft symbol 306 and the lateral deviation marks 308 point
towards an ILS source location (i.e., an ILS beacon located at an
endpoint of a runway) providing the pilot with direction
information via guidance symbology that can be understood
intuitively. Additional flight information may also be depicted on
the flight display 300.
[0028] The lateral deviation marks 308 are lateral deviation
indicators used to provide additional visual cues for determining
terrain and deviation line closure rate. The lateral deviation
marks 308 are used to represent both present deviations from the
centerline 302 and direction of aircraft movement. Thus, the
lateral deviation marks 308 provide a visual guide for closure rate
to the centerline 302 allowing the pilot to more easily align the
aircraft with the runway 304.
[0029] The graphics processor 110 generates the lateral deviation
marks 308 based on current aircraft parameters obtained from the
navigation system 104 and/or other avionic systems. The lateral
deviation marks 308 may be generated by computing terrain-tracing
projection lines at a number of fixed angles matching an emission
beam pattern of the runway ILS beacon. Sections of the
terrain-tracing lines in the forward looking perspective display
view may be used to generate the lateral deviation marks 308.
[0030] The lateral deviation marks 308 are depicted in FIG. 3 as
being centered about the centerline 302. The lateral deviation
marks 308 may be located at a predetermined distance from the
centerline 302. For example, the lateral deviation marks 308
located closest to the centerline 302 may be displayed one degree
of deviation from the centerline 302, while the next closest
lateral deviation marks 308 may be two degrees of deviation from
the centerline 302 as measured from the runway beacon beam
location. Other. predetermined distances, such as a fixed distance
(e.g., 1000 feet) may be used for rendering the lateral deviation
marks 308 with respect to the centerline 302.
[0031] The lateral deviation marks 308 may also be centered about
the aircraft symbol 306 as seen in flight display 400 depicted in
FIG. 4. The pilot may be able to choose the formatting of the
symbology to be centerline centered or aircraft centered based on
personal preference and/or current flight conditions. Generally,
one mode is selected by the pilot during a landing.
[0032] FIG. 5 illustrates a flight display 500. The flight display
500 is another example of terrain augmented display symbology
generated by the graphics processor 110. The flight display 500
depicts a centerline 502 ending at a runway 504. In addition, the
flight display 500 depicts an aircraft symbol 506 and lateral
deviation marks 508.
[0033] The flight display 500 depicts an image that may be
generated when an ILS signal is not available. In this scenario,
deviation scales and the aircraft's position may be determined
using data from a Flight Management System (FMS) and runway data.
An aircraft symbol 506 provides a visual cue of the aircraft's
current track and/or heading. Once the ILS becomes available, the
graphics processor 110 may transition to providing deviation
measurements using the ILS.
[0034] FIG. 6 is a flow diagram 600 depicting a method for
providing terrain augmented display symbology. At block 602, a
determination is made as to whether a runway is selected for
approach and landing. The graphics processor 110 may check an FMS
flight plan and/or receive input directly from the pilot to
determine if a runway is selected. At block 604, if a runway has
not been selected, the method returns to block 602 to determine
whether a runway is now selected.
[0035] If a runway has been selected, at block 606, runway
information regarding the selected runway is obtained. The graphics
processor 110 may obtain runway information from an on-board FMS
database and/or via a data link. The runway information includes
the size and position of the selected runway. Additional
information regarding the runway may also be available.
[0036] At block 608, the distance from the aircraft to the selected
runway is calculated. The graphics processor 110 calculates the
distance using the runway information obtained at block 606 and the
current position of the aircraft. The current position of the
aircraft may be obtained from the ILS or FMS. When the ILS signal
is available, the current aircraft position may be calculated by
using lateral (angle) deviation data obtained from the avionic
systems 102-108. Without the ILS signal, the current aircraft
position may be determined by the FMS and/or GPS.
[0037] At block 610, the distance to the runway is compared to a
threshold value for determining whether to display approach
symbology. The threshold value may be a predetermined value used to
identify at what distance the pilot should start receiving approach
information. The threshold value may be based on the selected
runway and approach direction. For example, the pilot should not
receive the approach symbology too soon as the symbology may
distract the pilot from more immediate flight concerns. However,
the pilot should receive the approach symbology soon enough to plan
and implement a safe landing on the selected runway.
[0038] If the distance to the runway is greater than the threshold
value, then the method returns to block 608 to determine whether
the distance to the runway is now less than the threshold value.
Otherwise, at block 612, an approach course to the runway is
determined. The approach course and direction may be calculated
based on ILS beam direction, runway direction, and/or final
approach procedure direction.
[0039] At block 614, a terrain-tracing centerline is generated
along the approach course determined at block 612. The graphics
processor 110 generates a terrain-tracing centerline by first
computing lateral coordinates along the centerline and then
retrieving terrain elevation data from the terrain database 112
based on the coordinates. The terrain-tracing centerline may be
displayed in a color that is visible on the rendered terrain
background.
[0040] At block 616, an aircraft symbol is generated. The aircraft
symbol may be rendered in two modes. In a first mode, the aircraft
symbol may be oriented to indicate current track position. In a
second mode, the aircraft symbol may be oriented to indicate both
current track position and the direction of travel. In the second
mode, the aircraft symbol may point towards the ILS beam location.
In both the first and second mode, the aircraft symbol provides
aircraft position information with respect to the centerline.
[0041] The aircraft symbol may be rendered in a color that can
easily be seen by the pilot with respect to the rendered background
terrain. The color of the aircraft symbol may also indicate ILS
signal or FMS position based operation.
[0042] At block 618, lateral deviation marks are generated. The
lateral deviation marks may be computed based on angle emission
lines from the ILS beam location and terrain elevation data from
the terrain database 112. A small segment of the emission lines may
be used to generate the lateral deviation marks.
[0043] The lateral deviation marks may be rendered in a color that
can easily be seen by the pilot with respect to the rendered
background terrain. The color of the lateral deviation marks may
also indicate ILS signal or FMS position based operation. Further,
the lateral deviation marks may be rendered so that they are
centered about the centerline symbol or centered about the aircraft
symbol.
[0044] Terrain augmented conformal lateral deviation display
symbology improves a pilot's spatial awareness during aircraft
approach and landing. The pilot may be able to quickly interpret
the symbology and take actions based on the elevation of the
surrounding terrain. As a result, aircraft navigation may be
simplified, pilot error and fatigue may be reduced, and safety may
be increased.
[0045] It should be understood that the illustrated embodiments are
examples only and should not be taken as limiting the scope of the
present invention. For example, while ILS was used to describe the
invention, the symbology may also be used with MLS and SLS systems.
The claims should not be read as limited to the described order or
elements unless stated to that effect. Therefore, all embodiments
that come within the scope and spirit of the following claims and
equivalents thereto are claimed as the invention.
* * * * *