U.S. patent application number 16/708942 was filed with the patent office on 2020-08-06 for directional lighting fitted to an aircraft, and an associated lighting method.
This patent application is currently assigned to AIRBUS HELICOPTERS. The applicant listed for this patent is AIRBUS HELICOPTERS. Invention is credited to Marc SALESSE-LAVERGNE.
Application Number | 20200247557 16/708942 |
Document ID | / |
Family ID | 1000004970198 |
Filed Date | 2020-08-06 |
United States Patent
Application |
20200247557 |
Kind Code |
A1 |
SALESSE-LAVERGNE; Marc |
August 6, 2020 |
DIRECTIONAL LIGHTING FITTED TO AN AIRCRAFT, AND AN ASSOCIATED
LIGHTING METHOD
Abstract
A directional lighting system fitted to an aircraft and
comprising firstly a light source mounted on a motor-driven support
and secondly a control device serving to control the motor-driven
support. According to the invention, such a directional lighting
system comprises a selector member for selecting a pointing target
that is to be pointed to, a camera for acquiring a plurality of
images of the surroundings outside the aircraft, image processor
means for identifying the selected pointing target, a calculation
unit configured to calculate the current coordinates of the
pointing target, and a servocontrol member of the control device
for servocontrolling the position of the motor-driven support to
occupy an angular orientation as determined by the calculation
unit.
Inventors: |
SALESSE-LAVERGNE; Marc;
(Allauch, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AIRBUS HELICOPTERS |
Marignane Cedex |
|
FR |
|
|
Assignee: |
AIRBUS HELICOPTERS
Marignane Cedex
FR
|
Family ID: |
1000004970198 |
Appl. No.: |
16/708942 |
Filed: |
December 10, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D 47/04 20130101;
B64D 47/08 20130101; F21V 21/15 20130101 |
International
Class: |
B64D 47/04 20060101
B64D047/04; B64D 47/08 20060101 B64D047/08; F21V 21/15 20060101
F21V021/15 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2019 |
FR |
1900910 |
Claims
1. A directional lighting system fitted to an aircraft, the
directional lighting system comprising: at least one light source
mounted on a motor-driven support, the motor-driven support
presenting at least one degree of freedom to move in rotation
relative to a fuselage of the aircraft; a control device serving to
control the motor-driven support to occupy at least one angular
orientation, the at least one angular orientation being relative to
a pointing direction of the light source(s) in a first reference
frame associated with the fuselage of the aircraft; wherein the
directional lighting system comprises: a selector member for
selecting a pointing target that is to be pointed to by the
pointing direction; at least one camera for acquiring a plurality
of images of the surroundings outside the aircraft in the pointing
direction; image processor means for identifying the pointing
target, as selected by the selector member, in at least one image
from among the plurality of images; a calculation unit configured
to calculate current coordinates of the pointing target as
identified by the image processor means, the current coordinates
being determined in the first reference frame from the plurality of
images acquired by the at least one camera, the calculation unit
being configured to use the current coordinates of the pointing
target to determine the at least one angular orientation in the
first reference frame; and a servocontrol member of the control
device to servocontrol a position of the motor-driven support to
occupy at least the at least one angular orientation as determined
by the calculation unit.
2. The system according to claim 1, wherein the servocontrol member
servocontrols the position of the motor-driven support to occupy
the at least one angular orientation as determined by the
calculation unit when the pointing target is selected via the
selector member by a pilot of the aircraft.
3. The system according to claim 1, wherein the directional
lighting system includes measurement means for measuring values of
current components of a speed vector of the aircraft relative to
the ground, the current components being determined in a second
reference frame associated with the ground.
4. The system according to claim 3, wherein the servocontrol member
servocontrols the position of the motor-driven support to occupy a
predetermined angular orientation, the predetermined angular
orientation being variable as a function of at least one of the
values of the current components of the speed vector of the
aircraft relative to the ground, the pointing direction of the at
least one light source ranging from a minimum angle that is
downwardly oriented relative to a direction of advance of the
aircraft, to a maximum downwardly oriented angle corresponding to a
vertical direction parallel to a third axis of the first reference
frame.
5. The system according to claim 4, wherein the directional
lighting system includes a manual control member for controlling
the servocontrol member to servocontrol the position of the
motor-driven support to occupy the predetermined angular
direction.
6. The system according to claim 4, wherein the directional
lighting system includes a manual corrector member for manually
correcting the predetermined angular orientation of the
motor-driven support.
7. The system according to claim 1, wherein the at least one camera
is arranged on the motor-driven support.
8. The system according to claim 7, wherein the directional
lighting system includes a plurality of light sources surrounding
the at least one camera, the plurality of light sources being
arranged coaxially around the at least one camera about the
pointing direction.
9. The system according to claim 8, wherein the plurality of light
sources includes a remote light generator together with bundles of
optical fibers for conveying light from the light generator to the
proximity of the at least one camera.
10. A directional lighting method for an aircraft, the directional
lighting method comprising at least: a step of lighting at least
one light source mounted on a motor-driven support, the
motor-driven support presenting at least one degree of freedom to
move in rotation relative to a fuselage of the aircraft; a control
step serving to control the motor-driven support to occupy at least
one angular orientation, the at least one angular orientation being
relative to a pointing direction of the at least one light source
in a first reference frame associated with the fuselage of the
aircraft; wherein the directional lighting method comprises a
succession of steps comprising at least: a selection step for
selecting a pointing target that is to be pointed to by the
pointing direction; at least one acquisition step for acquiring a
plurality of images of the surroundings outside the aircraft in the
pointing direction; an image processing step for identifying the
pointing target, as selected in the selection step, in at least one
image from among the plurality of images; a calculation step
configured to calculate current coordinates of the pointing target
as identified during the image processing step, the current
coordinates being determined in the first reference frame from the
plurality of images acquired during the acquisition step, the
calculation step being configured to use the current coordinates of
the pointing target to determine the at least one angular
orientation in the first reference frame; and a servocontrol step
of servocontrolling a control device performing the control step,
the servocontrol step serving to servocontrol a position of the
motor-driven support to occupy at least the at least one angular
orientation as determined during the calculation step.
11. The method according to claim 10, wherein the directional
lighting method includes a measurement step for measuring values of
current components of a speed vector of the aircraft relative to
the ground, the current components being determined in a second
reference frame associated with the ground.
12. The method according to claim 11, wherein the servocontrol step
servocontrols the position of the motor-driven support to occupy a
predetermined angular orientation at least prior to performing the
selection step, the predetermined angular orientation being
variable as a function of at least one of the values of the current
components of the speed vector of the aircraft relative to the
ground as measured in the measurement step, the pointing direction
of the at least one light source ranging from a minimum angle that
is downwardly oriented relative to a direction of advance of the
aircraft, to a maximum downwardly oriented angle corresponding to a
vertical direction parallel to a third axis of the first reference
frame.
13. The method according to claim 12, wherein after performing the
selection step, the directional lighting method includes a manual
control step for controlling the servocontrol step serving to
servocontrol the position of the motor-driven support to occupy the
predetermined angular orientation.
14. The method according to claim 12, wherein the directional
lighting method includes a manual correction step for manually
correcting the predetermined angular orientation of the
motor-driven support.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to French patent
application No. FR 1900910 filed on Jan. 31, 2019, the disclosure
of which is incorporated in its entirety by reference herein.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
[0002] The present invention relates to a system and a method for
providing directional lighting from an aircraft. In particular,
such an aircraft may consist in an airplane, a rotorcraft, or any
type of aircraft that is preferably capable of taking off and/or
landing vertically.
[0003] Also, such aircraft may advantageously carry on board one or
more pilots and/or passengers and/or goods.
[0004] More particularly, the invention relates to the field of
lighting systems comprising a light source mounted on a
motor-driven support presenting at least one degree of freedom to
move in rotation relative to a fuselage of the aircraft, and at
least one control device enabling the motor-driven support to be
controlled to occupy at least one angular orientation, the angular
orientation(s) being relative to a pointing direction of the light
source in a first reference frame associated with the fuselage of
the aircraft.
(2) Description of Related Art
[0005] In general manner, and as described in Documents FR 3 037
042 and U.S. Pat. No. 3,721,499, it is known to make devices for
causing lighting to track automatically a pad site for take-off or
landing of a rotorcraft. Under such circumstances, such a pad site
may be formed by a landing zone arranged on the ground or in a
reference frame of that is itself stationary relative to the
ground.
[0006] Furthermore, that Document FR 3 037 042 also discloses the
use of a system for measuring the altitude and the heading of the
rotorcraft, a two-axis accelerometer, and a radio altimeter so as
to know variations in the position of the rotorcraft relative to
the pad site of coordinates that are constant in a reference frame
associated with the ground.
[0007] Thus, such a tracking device obliges the pilot to perform a
first step of initializing the position of a searchlight in order
to pointed towards the pad site and then a storage step in order to
store the initial position of the searchlight.
[0008] Consequently, such a device does not make it possible for
the lighting to track automatically a pad site that is movable in
the reference frame associated with the ground. By way of example,
a movable landing and/or take-off site may be situated on an
offshore platform, on a ship, or more generally on any type of
vehicle that is moving relative to the ground.
[0009] Furthermore, as described in Document EP 3 231 714, it is
also known to fit an aircraft with a camera to acquire a plurality
of images of the surroundings outside the aircraft. Image processor
means then serve to identify a focus of expansion between two
images so as to make it possible to identify potential deviation of
the approaching aircraft relative to a landing strip and to modify
correspondingly the orientation direction in which a light source
of a lighting system arranged on the aircraft is pointed.
[0010] Nevertheless, such image processor means serve to determine
values of current components of a speed vector of the aircraft
relative to the ground and then to steer the light source as a
function of those values.
[0011] Consequently, and as above, such a device does not make it
possible for the lighting to track automatically a pad site that is
movable in the reference frame associated with the ground.
[0012] Furthermore, such a lighting system is more particularly
adapted to enable an aircraft to provide lighting during a stage of
landing on a strip or runway that is long and not a pad.
[0013] Furthermore, as described in particular in Documents FR 3
053 821 and WO 2018/035835, is also known to fit an aircraft such
as a rotorcraft or a drone with a camera, with image processor
means, and a calculation unit for calculating current coordinates
of at least one landing zone in a reference frame associated with
the rotorcraft. These current coordinates are determined from the
plurality of images acquired by the camera.
[0014] Finally, in Document FR 3 053 821, a control unit serves to
generate a control setpoint for automatically piloting the
rotorcraft towards a desired landing zone.
[0015] Nevertheless, although such a device enables a rotorcraft to
be piloted automatically towards a landing zone with a
predetermined flight path, it does not serve to control the
orientation of a light source pointed towards a landing zone, and
consequently to track that landing zone automatically.
BRIEF SUMMARY OF THE INVENTION
[0016] An object of the present invention is thus to provide a
lighting system making it possible to be unaffected by the
above-mentioned limitations. Specifically, an object of the
invention is to provide lighting and automatic tracking of a
pointing target that may be movable in a reference frame associated
with the ground, e.g. such as an offshore platform, a ship, or more
generally any vehicle moving relative to the ground.
[0017] As mentioned above, the invention provides a directional
lighting system fitted to an aircraft, the lighting system
comprising:
[0018] at least one light source mounted on a motor-driven support,
the motor-driven support presenting at least one degree of freedom
to move in rotation relative to a fuselage of the aircraft;
[0019] a control device serving to control the motor-driven support
to occupy at least one angular orientation, the orientation(s)
being relative to a pointing direction of the light source(s) in a
first reference frame associated with the fuselage of the
aircraft.
[0020] According to the invention, such a directional lighting
system is remarkable in that it comprises:
[0021] a selector member for selecting a pointing target that is to
be pointed to by the pointing direction;
[0022] at least one camera for acquiring a plurality of images of
the surroundings outside the aircraft in the pointing
direction;
[0023] image processor means for identifying the pointing target,
as selected by the selector member, in at least one image from
among the plurality of images;
[0024] a calculation unit configured to calculate current
coordinates of the pointing target as identified by the image
processor means, the current coordinates being determined in the
first reference frame from the plurality of images acquired by the
camera(s), the calculation unit being configured to use the current
coordinates of the pointing target to determine the angular
orientation(s) in the first reference frame; and
[0025] a servocontrol member of the control device to servocontrol
the position of the motor-driven support to occupy the angular
orientation(s) as determined by the calculation unit.
[0026] In other words, and by way of example, the selector member
serving to select a pointing target may comprise a monitor screen
displaying an image of one or more landing zones towards which the
aircraft is heading. A pilot of the aircraft can then select the
pointing target by using a finger to touch a touch-sensitive zone
of the monitor screen associated with selecting the pointing
target.
[0027] By way of example, such a monitor screen may be integrated
in the control panel of the aircraft cockpit, or it may be a
portable screen, such as a touch tablet, or indeed it may be remote
from the aircraft when the aircraft is remotely controlled and
consequently does not have a pilot on board.
[0028] Furthermore, the camera(s) may advantageously be arranged
below a fuselage of the aircraft and may be stationary or steerable
relative to the fuselage. In particular, the camera(s) may thus be
selected to be of the "pan-tilt-zoom" type, i.e. firstly having two
degrees of freedom to move in rotation through a bearing angle and
an elevation angle relative to a travel direction of the aircraft,
and secondly having the ability to magnify in the direction of the
pointing target.
[0029] The images required by the camera(s) are then transmitted to
the image processor means that are configured to identify the
pointing target, as selected via the selector member, in at least
one image from among the plurality of images. By way of example,
such image processor means may comprise a computer, calculation
means, a processor, an integrated circuit, a programmable system,
or indeed a logic circuit.
[0030] Such identification of a selected pointing target is
performed in a plurality of steps. Initially, it is possible to
proceed with detecting a horizon line using a so-called "gradient"
method. More precisely, such a method consists in using a vertical
"Sobel" filter on an image. Such a method thus serves to amplify
contrast and to detect horizontal lines. Thereafter, it suffices to
find the straight line that passes through the greatest number of
points by using a "Hough" transform. In practice, the horizon line
in the image is not exactly a straight line, but rather an arc of a
parabola.
[0031] Nevertheless, detecting the horizon line approximately is
not troublesome, since detecting the horizon line serves only to
eliminate the top portion of the image that corresponds to the sky
and that is not useful for detecting the pointing target.
[0032] Furthermore, the angle of inclination of the aircraft about
a roll axis is taken into account by the processor means using
auxiliary on-board instruments giving the attitude of the aircraft
at all times, consequently making it possible to determine the
angle of rotation for obtaining an outstanding image corresponding
to the horizontal attitude of the aircraft.
[0033] Once the horizon line has been identified and the sky
eliminated, the processor means perform a so-called "by region"
method as described for another application in a publication by
Arnaud Le Troter, Sebastien Mavromatis, and Jean Sequeira, entitled
"Soccer field detection in video images using color and spatial
coherence--International Conference on Image Analysis and
Recognition Porto, Portugal, October 2004".
[0034] Such a by region method then makes it possible to search for
dominant colors in an image or a zone of interest by color
distribution. That method also makes it possible to search for
image zones that present color coherence, and then it makes use of
an enlargement model on the pixels of the image. Such a model is
known for recognizing color pixels making up images and can make
use of a color representation space such as that known as hue,
saturation, lightness (HSL).
[0035] Such a method by region makes it possible in particular to
detect the sea in a low portion of the image lying below the
horizon line, and the sky in the high portion of the image and
arranged above the horizon line.
[0036] Thereafter, grouping the remaining pixels together in
connected zones serves to obtain zones comprising one (or more)
selected pointing targets. Any connected zones that are present in
the sky only are removed, since they generally correspond to
clouds, smoke, and flying objects, and do not correspond to
potential pointing targets to be identified.
[0037] Coherence zones are formed by allocating an "HSL" zone to
each pixel, or else no HSL zone whenever the color of the pixel
does not lie in any of the dominant HSL zones (or dominant colors
of the image). Thereafter, the processor means serve to create
connected zones of pixels all belonging to the same HSL zone.
[0038] The phenomenon of enlarging a pixel to a zone is performed
by applying a mathematical morphology tool corresponding to a
closure. The structuring element selected for closure is a circle
of size much smaller than the minimum sizes for the landing
target(s) that it is desired to identify in the image. The size
selected for the structuring element is of the order of one tenth
the size of the objects to be detected.
[0039] The zones that are obtained are then identified as potential
pointing targets and they may be displayed independently by the
display means and then selected by the crew.
[0040] Thus, once the selected pointing target has been identified,
the calculation unit then calculates current coordinates for the
pointing target in the first reference frame associated with the
fuselage of the aircraft, and it determines the angular
orientation(s) in the first reference frame.
[0041] Like the above image processor means, such a calculation
unit may, for example, comprise a computer, calculation means, a
processor, an integrated circuit, a programmable system, or indeed
a logic circuit.
[0042] Also, the image processor means and the calculation unit may
be formed by mutually distinct elements, or indeed they may be the
same as each other, e.g. constituting a single computer.
[0043] The servocontrol member then makes it possible at all times
to modify the position of the motor-driven support so as to track
the angular orientation(s) as determined by the calculation unit.
Also, the motor-driven support may advantageously have two degrees
of freedom to move in rotation through both an elevation angle and
also a bearing angle relative to a travel direction of the
aircraft. Under such circumstances, the position of the
motor-driven support may be modified to occupy two distinct angular
orientations, and at all times, the calculation unit determines a
first angular orientation at an elevation angle and a second
angular orientation at a bearing angle.
[0044] In practice, the servocontrol member may servocontrol the
position of the motor-driven support to occupy the angular
orientation(s) as determined by the calculation unit when the
pointing target is selected via the selector member by a pilot of
the aircraft.
[0045] Thus, as soon as the pointing target is selected by a pilot
of the aircraft, the servocontrol member of the control device
servocontrols the position of the motor-driven support to occupy at
least the angular orientation(s) determined by the calculation
unit.
[0046] Advantageously, the directional lighting system may include
measurement means for measuring the values of the current
components of a speed vector of the aircraft relative to the
ground, the current components being determined in a second
reference frame associated with the ground.
[0047] In particular, such measurement means may comprise a member
for measuring the altitude and the heading of the aircraft, one or
more accelerometers, and one or more satellite geolocation modules,
such as a GPS module.
[0048] In an advantageous embodiment of the invention, the
servocontrol member may servocontrol the position of the
motor-driven support to occupy a predetermined angular orientation,
the predetermined angular orientation being variable as a function
of at least one of the values of the current components of the
speed vector of the aircraft relative to the ground, the pointing
direction of the light source(s) ranging from a minimum angle that
is oriented downwardly, i.e. towards the ground, relative to a
direction of advance of the aircraft, to a maximum downwardly
oriented angle corresponding to a vertical direction parallel to a
third axis of the first reference frame.
[0049] In other words, the servocontrol member serves to
servocontrol the position of the motor-driven support to occupy a
predetermined angular orientation of value that can vary as a
function of one or more values of the current components of the
speed vector of the aircraft relative to the ground. Under such
circumstances, the aircraft then includes measurement means as
described above for measuring the values of the current components
of a speed vector.
[0050] Thus, during a stage of hovering flight of the aircraft,
corresponding to current components of zero value for the speed
vector of the aircraft relative to the ground, the servocontrol
member may servocontrol the position of the motor-driven support so
that the pointing direction of the light source(s) is downwardly
oriented perpendicularly to a plane formed by a roll axis and by a
pitching axis of the aircraft.
[0051] In contrast, during a stage of flight in which the speed
vector of the aircraft relative to the ground presents non-zero
current components, the servocontrol member serve to servocontrol
the position of the motor-driven support so that the pointing
direction of the light source(s) points downwards at an angle of
3.degree. relative to the direction of advance and below the plane
formed by a roll axis and by a pitching axis of the aircraft.
[0052] Advantageously, the directional lighting system may include
a manual control member for controlling the servocontrol member to
servocontrol the position of the motor-driven support to occupy the
predetermined angular direction.
[0053] In other words, the manual control member can serve to pass
from a first mode of servocontrolling the position of the
motor-driven support to a second mode of servocontrolling the
position of the motor-driven support.
[0054] In the first mode of servocontrol, the motor-driven support
is servocontrolled to occupy the angular orientation(s) as
determined by the calculation unit. In contrast, in the second mode
of servocontrol, the servocontrol member serves to servocontrol the
position of the motor-driven support to occupy the predetermined
angular orientation, which may for example be stored in a storage
unit on board the aircraft or in an external storage unit.
[0055] In an advantageous embodiment of the invention, the
directional lighting system may include a manual corrector member
for manually correcting the predetermined angular orientation of
the motor-driven support.
[0056] By way of example, such a manual corrector member may be a
joystick, or any other manual control member that is movable in
both directions along at least one axis or that presents at least
one degree of freedom to move in rotation while being movable in
both directions of rotation. Such a manual corrector member is thus
suitable for correcting the predetermined angular orientation of
the motor-driven support in both directions of the degree(s) of
freedom that it possesses, e.g. relative to an element of the
aircraft cockpit.
[0057] Advantageously, the camera(s) may be arranged on the
motor-driven support.
[0058] In other words, the camera(s) is/are movable together with
the light source(s). In this way, the camera(s) can constantly
track the pointing direction of the light source(s).
[0059] In practice, the directional lighting system may include a
plurality of light sources surrounding the camera(s), the plurality
of light sources being arranged coaxially around the camera(s)
about the pointing direction.
[0060] Thus, by way of example, the lighting system may include a
central camera with a plurality of light sources that may be
regularly distributed around the central camera. Under such
circumstances, the pointing direction of the assembly formed by the
plurality of light sources then coincides with the orientation of
an optical axis of the central camera.
[0061] Also, the plurality of light sources may be formed by
light-emitting diodes (LEDs) arranged on a plane support and fed
directly with electrical power in order to generate a light
beam.
[0062] In an advantageous embodiment of the invention, the
plurality of light sources may include a remote light generator
together with bundles of optical fibers for conveying light from
the light generator to the proximity of the camera(s).
[0063] Under such circumstances, the light generator may be
arranged in a stationary zone of the aircraft, the stationary zone
being secured to the fuselage of the aircraft and being arranged
not on the motor-driven support. Thus, the bundles of optical
fibers may serve to convey light all around the camera and very
close to the camera.
[0064] Such an embodiment is advantageous since optical fibers
present intrinsic flexibility and are suitable for deforming freely
in order to track the movements of the motor-driven support.
Furthermore, such optical fibers serve to convey a large quantity
of light without generating heat in the proximity of the
camera.
[0065] The present invention also provides a directional lighting
method for an aircraft, the directional lighting method comprising
at least:
[0066] a step of lighting at least one light source mounted on a
motor-driven support, the motor-driven support presenting at least
one degree of freedom to move in rotation relative to a fuselage of
the aircraft;
[0067] a control step serving to control the motor-driven support
to occupy at least one angular orientation, the orientation(s)
being relative to a pointing direction of the light source(s) in a
first reference frame associated with the fuselage of the
aircraft.
[0068] According to the invention, the directional lighting method
is remarkable in that it comprises a succession of steps comprising
at least:
[0069] a selection step for selecting a pointing target that is to
be pointed to by the pointing direction;
[0070] an acquisition step for acquiring a plurality of images of
the surroundings outside the aircraft in the pointing direction; an
image processing step for identifying the pointing target, as
selected in the selection step, in at least one image from among
the plurality of images;
[0071] a calculation step configured to calculate current
coordinates of the pointing target as identified during the image
processing step, the current coordinates being determined in the
first reference frame from the plurality of images acquired during
the acquisition step, the calculation step being configured to use
the current coordinates of the pointing target to determine the
angular orientation(s) in the first reference frame; and
[0072] a servocontrol step of servocontrolling a control device
performing the control step, the servocontrol step serving to
servocontrol the position of the motor-driven support to occupy at
least the angular orientation(s) as determined during the
calculation step.
[0073] In other words, and by way of example, the selection step
serving to select a pointing target may be performed by means of a
monitor screen displaying an image of one or more landing zones
towards which the aircraft is heading. By way of example, the
selection step may then be performed by a pilot of the aircraft
using a finger to touch a touch-sensitive zone of the monitor
screen associated with selecting the pointing target.
[0074] The acquisition step is performed by means of one or more
cameras advantageously arranged under the fuselage of the aircraft
and stationary or steerable relative to the fuselage. As mentioned
above, the camera(s) may thus in particular be of the
"pan-tilt-zoom" type.
[0075] The images acquired by the camera(s) are then transmitted to
image processor means in order to perform the image processing
step. Specifically, the image processor means are configured to
identify the pointing target, as selected during the selection
step, in at least one image from among the plurality of images. By
way of example, such image processor means may comprise a computer,
calculation means, a processor, an integrated circuit, a
programmable system, or indeed a logic circuit.
[0076] When the selected pointing target is identified during the
image processing step, the calculation step then serves to
calculate the current coordinates of the pointing target in the
first reference frame associated with the fuselage of the aircraft,
and to determine the angular orientation(s) in the first reference
frame.
[0077] Like the above image processing step, such a calculation
step may be performed, for example, by a computer, calculation
means, a processor, an integrated circuit, a programmable system,
or indeed a logic circuit.
[0078] As mentioned above, the image processing step and the
calculation step may be performed by elements that are mutually
distinct, or else by elements that are the same as each other, in
which case they form a single computer, for example.
[0079] The servocontrolling step may modify the position of the
motor-driven support so as to track the angular orientation(s) as
determined during the preceding calculation step. Also, the
motor-driven support may advantageously have two degrees of freedom
to move in rotation through both an elevation angle and also a
bearing angle relative to a travel direction of the aircraft. Under
such circumstances, the position of the motor-driven support may be
modified to occupy two distinct angular orientations, and at all
times, the calculation unit determines a first angular orientation
at an elevation angle and a second angular orientation at a bearing
angle.
[0080] Advantageously, the directional lighting method may include
a measurement step for measuring the values of the current
components of a speed vector of the aircraft relative to the
ground, the current components being determined in a second
reference frame associated with the ground.
[0081] In particular, such a measuring step may make use of a
member for measuring the altitude and the heading of the aircraft,
one or more accelerometers, and one or more satellite geolocation
modules, such as a GPS module.
[0082] In an advantageous implementation of the invention, the
servocontrol step may servocontrol the position of the motor-driven
support to occupy a predetermined angular orientation at least
prior to performing the selection step, the predetermined angular
orientation being variable as a function of at least one of the
values of the current components of the speed vector of the
aircraft relative to the ground as measured in the measurement
step, the pointing direction of the light source(s) ranging from a
minimum angle that is downwardly oriented relative to a direction
of advance of the aircraft, to a maximum downwardly oriented angle
corresponding to a vertical direction parallel to a third axis of
the first reference frame.
[0083] In other words, prior to the step of the pilot selecting the
pointing target, the predetermined angular orientation of the
motor-driven support may vary automatically as a function of at
least one of the values of the current components of the speed
vector of the aircraft relative to the ground. Under such
circumstances, such servocontrol of the position of the
motor-support to occupy a predetermined angular position may
correspond to an initial mode of servocontrol.
[0084] Advantageously, after performing the selection step, the
directional lighting method may include a manual control step for
controlling the servocontrol step serving to servocontrol the
position of the motor-driven support to occupy the predetermined
angular orientation.
[0085] In other words, and by way of example, this manual control
step enables the pilot of the aircraft to go from a first mode of
servocontrolling the position of the motor-driven support to a
second mode of servocontroliing the position of the motor-driven
support. Also, such a second mode of servocontrol may correspond to
the initial mode of servocontrol that is performed prior to the
first mode of servocontrolling the position of the motor-driven
support.
[0086] In practice, the directional lighting method may include a
manual correction step for manually correcting the predetermined
angular orientation of the motor-driven support.
[0087] Thus, by way of example, such a manual correction step may
be performed by actuating a joystick, or any other manual control
member that is movable in both directions along at least one axis
or that presents at least one degree of freedom to move in rotation
while being movable in both directions of rotation. Such a manual
correction step then makes it possible to correct the predetermined
angular orientation of the motor-driven support in both directions
of the degree(s) of freedom that it possesses, e.g. relative to an
element of the aircraft cockpit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0088] The invention and its advantages appear in greater detail in
the context of the following description of embodiments given by
way of illustration and with reference to the accompanying figures,
in which:
[0089] FIG. 1, is a side view of an aircraft fitted with a
directional lighting system in accordance with the invention;
[0090] FIG. 2, is a plan view of an aircraft fitted with a
directional lighting system in accordance with the invention;
[0091] FIG. 3, is a front view of a first variant of a directional
lighting system in accordance with the invention;
[0092] FIG. 4, is a side view of a second variant of a directional
lighting system in accordance with the invention; and
[0093] FIG. 5, is a flowchart showing steps of a directional
lighting method in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0094] Elements that are present in more than one of the figures
are given the same references in each of them.
[0095] As mentioned above, the invention relates to a directional
lighting system for fitting to an aircraft.
[0096] As shown in FIG. 1, such a directional lighting system 1 may
be mounted on an aircraft and serve to light a pointing target, in
particular such as a landing zone.
[0097] Thus, the directional lighting system 1 has at least one
light source 3 mounted on a motor-driven support 4. Also, such a
motor-driven support 4 presents at least one degree of freedom to
move in rotation relative to a fuselage 5 of the aircraft 2, and
preferably two degrees of freedom to move in rotation relative to
the fuselage 5.
[0098] The directional lighting system 1 also has a control device
to 6 for controlling movements of the motor-driven support 4 to
occupy at least one angular orientation, and preferably to occupy
two angular orientations .alpha., .beta., .alpha.', .beta.'. This,
or these, angular orientation(s) .alpha., .beta., .alpha.', .beta.'
is/are then relative to a pointing direction D1 of the light
source(s) 3 in a first reference frame R1 associated with said
fuselage 5 of the aircraft 2.
[0099] By way of example, such a first reference frame R1 may
comprise a first axis OX.sub.1 aligned with a heading axis of the
aircraft 2 arranged substantially horizontally and capable of being
offset through a drift angle relative to a direction of advance D2
of the aircraft 2. The reference frame R1 then also has a second
axis OY.sub.1 likewise arranged horizontally, being perpendicular
to the first axis OX.sub.1. Finally, the reference frame R1 has a
third axis OZ arranged vertically and thus being perpendicular to
both the first and second axes OX.sub.1 and OY.sub.1.
[0100] Furthermore, the directional lighting system 1 includes a
selector member 7 enabling a pilot of the aircraft to select a
pointing target to which the light source(s) 3 is/are to point, and
thus to which the pointing direction D1 is to point.
[0101] As shown, the directional lighting system 1 includes at
least one camera 8 likewise mounted on the motor-driven support 4
and serving to acquire a plurality of images of the surroundings
outside the aircraft 2 in the pointing direction D1.
[0102] Image processor means 9 arranged on the aircraft 2 then
serve to identify the pointing target, as selected by the selector
member 7, in at least one of the images from among the images
acquired by the camera 8.
[0103] A calculation unit 10, which may likewise be arranged on the
aircraft 2, is then configured to calculate current coordinates of
the pointing target as identified by the image processor means 9.
Such a current coordinates are then determined in the first
reference frame R1 from the images acquired by the camera 8.
Thereafter, the calculation unit 10 is configured to use the
current coordinates of the pointing target to determine the angular
orientation .alpha. in the first reference frame R1.
[0104] Furthermore, the directional lighting system 1 also includes
a servocontrol member 11 of the control device 6 serving to
servocontrol the position of the motor-driven support 4 to occupy
the angular orientation .alpha. determined by the calculation unit
10.
[0105] Furthermore, and as shown, the directional lighting system 1
includes measurement means 12 arranged on the aircraft 2 to measure
the values of current components of a speed vector of the aircraft
2 relative to the ground S, these current components being
determined in a second reference frame R2 associated with the
ground S.
[0106] By way of example, such a reference frame R2 may include a
first axis OX.sub.2 arranged substantially horizontally and
pointing along a first direction. The reference frame R2 then also
has a second axis OY.sub.2 likewise arranged horizontally, being
perpendicular to the first axis OX.sub.2. Finally, the reference
frame R2 has a third axis OZ.sub.2 arranged vertically and thus
being perpendicular to the first and second axes OX.sub.2 and
OY.sub.2.
[0107] Advantageously, the directional lighting system 1 may also
include a manual control device 13, which may for example be
arranged on the aircraft 2 or else be located remotely on the
ground. Such a manual control member 13 then serves to control the
servocontrol member 11 to servocontrol the position of the
motor-driven support 4 to occupy a predetermined angular
orientation .alpha.'. Such a predetermined angular orientation
.alpha.' is then potentially distinct from the angular orientation
.alpha. determined by the calculation unit 10 in the first
reference frame R1.
[0108] Also, such a predetermined angular orientation .alpha.' may
be variable as a function of at least one of the values of the
current components of the speed vector of the aircraft 2 relative
to the ground S. Under such circumstances, the pointing direction
D1 of the light source 3 may then range from a minimum angle
.alpha..sub.1 that is oriented downwardly, i.e. towards the ground,
relative to a direction of advance D2 of the aircraft 2, to a
maximum angle .alpha..sub.2 oriented downwards and corresponding to
a vertical direction D3 parallel to the third axis OZ.sub.1 of the
first reference frame R1.
[0109] Furthermore, and as shown, the directional lighting system 1
may also include a manual correction member 14 making it possible,
if necessary, to correct manually the predetermined angular
orientation .alpha.' of the motor-driven support 4.
[0110] As shown in FIG. 2, the servocontrol member 11 serves to
servocontrol the position of the motor-driven support 4 to occupy
an angular orientation .beta. determined by the calculation unit 10
or indeed to occupy a predetermined angular orientation .beta.'.
Such a predetermined angular orientation .beta.' is then
potentially distinct from the angular orientation .alpha.
determined by the calculation unit 10 in the first reference frame
R1.
[0111] Advantageously, the predetermined angular orientations
.alpha.', .beta.' may be direct functions of the values of the
current components of the speed vector of the aircraft 2 relative
to the ground S, and thus relative to the reference frame R2.
[0112] More precisely, the predetermined angular orientation
.beta.' may be a function of the values of the horizontal
components Vx and Vy of the speed vector of the aircraft 2 along
the first axis OX.sub.2 and the second axis OY.sub.2, while the
predetermined angular orientation .alpha.' may be a function of the
value of a vertical component Vz of the speed vector of the
aircraft 2 along a third axis OZ.sub.2.
[0113] Also, when the horizontal components Vx and Vy of the speed
vector of the aircraft 2 are zero and when the vertical component
Vz along the third axis OZ.sub.2 exceeds a predetermined threshold
value Vzs, the predetermined angular orientation .alpha.' may then
be maintained equal to the maximum angle .alpha..sub.2. By way of
example, such a predetermined threshold value Vzs may be selected
to be negative, e.g. lying in the range -0.5 to -2.
[0114] In other words, the vertical component Vz along the third
axis OZ.sub.2 may be upwardly limited to a predetermined negative
threshold value so that the searchlight points downwards during
hovering. Such a predetermined threshold value Vzs may thus lie for
example in the range -0.5 to -2.
[0115] Furthermore, and as shown in FIG. 3, such a directional
lighting system 1 may include a plurality of light sources 3
surrounding a camera 8, being arranged on the motor-driven support
4. These light sources 3 then advantageously form a monolithic unit
arranged coaxially around the camera 8 about the pointing direction
D1.
[0116] As shown in FIG. 4, the plurality of light sources 3 may
also include a light generator 15 located remotely from the
motor-driven support 4. By way of example, such a light generator
15 may be secured to the fuselage 5 of the aircraft 2. The
plurality of light sources 3 also includes bundles of optical
fibers 16, thus serving to convey light from the light generator 15
to around the camera 8 arranged on the motor-driven support 4.
[0117] As shown in FIG. 5, and as mentioned above, the invention
also relates to a directional lighting method 20 for an aircraft
2.
[0118] Also, such a directional lighting method 20 may
advantageously include a measurement step 28 serving to measure the
values of the current components of a speed vector of the aircraft
2 relative to the ground S. These current components are then
determined in the second reference frame R2 associated with the
ground S.
[0119] The directional lighting method 20 may then include in
parallel a succession of steps 23, 24, 25, and 26 corresponding to
a first mode of operation, or a step 29 corresponding to a second
mode of operation.
[0120] Thus, in the first mode of operation, a selection step 23
enables at least a pilot of the aircraft 2 to select a pointing
target that is to be pointed to by a pointing direction D1
corresponding to the orientation of a light source 3 in a first
reference frame the R1 associated with the fuselage 5 of the
aircraft 2.
[0121] Thereafter, an acquisition step 24 is performed by at least
one camera 8 and serves to acquire a plurality of images of the
surroundings outside the aircraft 2 in the pointing direction
D1.
[0122] The directional lighting method 20 also includes an image
processing step 25 for identifying the pointing target, as selected
in the selection step 23, in at least one of the plurality of
images. Finally, a calculation step 26 is configured to calculate
the current coordinates of the pointing target as identified during
the image processing step 25. Also, such current coordinates are
determined in the first reference frame R1 from a plurality of
images acquired during the acquisition step 24.
[0123] Furthermore, the calculation step 26 is configured to use
the current coordinates of the pointing target to determine at
least one angular orientation .alpha., .beta. of a motor-driven
support 4 in the first reference frame R1, the light source 3 being
mounted on the motor-driven support 4. Also, such a motor-driven
support 4 presents at least one degree of freedom to move in
rotation relative to a fuselage 5 of the aircraft 2.
[0124] Finally, in this first mode of operation, the directional
lighting method 20 includes a servocontrol step 27 for
servocontrolling a control device 6 performing a step 21 of
lighting the light source 3 and a control step 22 enabling the
motor-driven support 4 to be controlled to occupy at least one
angular orientation .alpha., .beta., .alpha.', .beta.' relative to
the pointing direction D1.
[0125] Thus, in this first mode of operation, such a servocontrol
step 27 enables the position of the motor-controlled support 4 to
be servocontrolled to occupy the angular orientation .alpha.,
.beta. as determined during the calculation step 26.
[0126] Furthermore, the directional lighting method 20 may also
include a second mode of operation in which the servocontrol step
27 serves to servocontrol the position of the motor-driven support
4 to occupy a predetermined angular orientation .alpha.', .beta.'
that may advantageously be variable as a function of the values of
the current components of a speed vector of the aircraft 2 relative
to the ground S.
[0127] This predetermined angular orientation .alpha.', .beta.' may
then be different from the angular orientation .alpha., .beta. as
determined during the calculation step 26 that corresponds to the
first mode of operation.
[0128] Also, in order to engage the second mode of operation, the
directional lighting method 20 may then include a manual control
step 29 for configuring the servocontrol step 27 so as to
servocontrol the position of the motor-driven support 4 to occupy a
predetermined angular orientation .alpha.', .beta.'.
[0129] Finally, such a directional lighting method 20 may
advantageously include a manual correction step 34 manually
correcting the predetermined angular orientation .alpha.', .beta.'
of the motor-driven support 4.
[0130] Naturally, the present invention may be subjected to
numerous variations as to its implementation. Although several
embodiments are described, it should readily be understood that it
is not conceivable to identify exhaustively all possible
embodiments. It is naturally possible to envisage replacing any of
the means described by equivalent means without going beyond the
ambit of the present invention.
* * * * *