Method of assisting in the navigation of a rotorcraft by dynamically displaying a representation of the outside world constructed in flight in instantaneous and/or deferred manner

Patent metadata

Field	Value
Publication number	US-9441972-B2
Application number	US-201514597407-A
Country	US
Kind code	B2
Filing date	Jan 15, 2015
Priority date	Jan 20, 2014
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A method of assisting in the navigation of a rotorcraft by displaying in flight a dynamic representation of the outside world (Me) in the event of a loss of visibility (brown-out/white-out). Front maps with incorporated localization are generated on the basis of front images captured by a set of front cameras. Terrain elevation data is generated from images captured by complementary sets of lateral and rear cameras. In the event of a loss of visibility, a reconstituted world (Mr) is prepared from the front maps with incorporated localization. On request of the pilot, an extrapolated world (Mex) is prepared by adding terrain elevation data to the front maps with incorporated localization, in compliance with the common time and the relative positions of the various sets of cameras between one another.

First claim

What is claimed is:

1. A method of operating a navigation assistance system of a rotorcraft by constructing and dynamically displaying in flight a representation of the outside world (Me) on a screen, said method comprising the following operations performed in flight:
on request of the pilot, sequentially capturing front images relating to the environment outside the rotorcraft by means of at least one set of front cameras on board the rotorcraft and oriented along a common front line of sight;
sequentially preparing by calculation front maps with incorporated localization on the basis of the front images and of navigation data of the rotorcraft provided by the on-board instrumentation simultaneously with the front images being captured sequentially, and then storing said front maps with incorporated localization in a first database; and
identifying a loss-of-visibility situation leading to a dynamic representation of the outside world (Me) referred to as the “reconstituted” world (Mr) being constructed by calculation and being displayed on the screen on the basis of sequentially extracting front maps with incorporated localization stored in the first database in compliance with variation in the current navigation data of the rotorcraft as compared with the navigation data incorporated in the front maps with incorporated localization;
simultaneously with capturing front images, sequentially capturing complementary images relating to the environment outside the rotorcraft by means of complementary sets of cameras, stereoscopic images delivered individually by the cameras of the various sets of cameras of the rotorcraft being referred to as “captured” images, the complementary sets of cameras comprising at least one set of right lateral cameras, at least one set of left lateral cameras, and at least one set of rear cameras, the cameras in any given complementary set of cameras being oriented on a common line of sight;
allocating by calculation to each of the captured images both time data delivered by the on-board instrumentation and origin data relating to the identity of the set of cameras from which the captured images stem, by generating metadata for each captured image, the metadata associating at least the captured images, said time data and said origin data, and including front metadata specific to the front images and incorporated in the maps with incorporated localization that are stored in said first database and also complementary metadata specific to the complementary images delivered by given respective sets of complementary cameras;
storing the complementary metadata in a second database and preparing sequentially by calculation said front maps with incorporated localization; and
on request of the pilot, constructing by calculation and displaying on the screen a dynamic representation of the outside world (Me) referred to as the “extrapolated” world (Mex), the extrapolated world (Mex) being made up of the front maps with incorporated localization as extracted sequentially from the first database in compliance with variation in the current navigation data of the rotorcraft as compared with the navigation data incorporated in the front maps with incorporated localization, which front maps with incorporated localization have added thereto complementary terrain elevation data coming from the complementary data, said adding being performed by correlating the time data and the origin data respectively allocated to the front images and to the complementary images, said correlation making use of the variation in the current navigation data of the rotorcraft to identify the relative positions between the front maps with incorporated localization and the complementary terrain elevation data from the captured images delivered at a given instant by the various sets of cameras.

2. The method according to claim 1 , wherein the complementary terrain elevation data is constituted at least in part by the complementary metadata that is selectively extracted from the second database and added to the front maps with incorporated localization.

3. The method according to claim 2 , wherein following the request from the pilot for construction and dynamic display of the extrapolated world (Mex), the method further comprises the following operations:
as the display of the extrapolated world (Mex) varies dynamically, verifying by calculation the availability of complementary maps with incorporated localization suitable for being correlated with the front maps with incorporated localization in order to construct and display the extrapolated world (Mex); then
if complementary maps with incorporated localization are available, constructing and displaying the extrapolated world (Mex), otherwise:
preparing complementary maps with incorporated localization needed for constructing and displaying the extrapolated world (Mex), providing the navigation assistance system has calculation capacity that is evaluated as being available relative to the calculation capacity threshold; else
extracting by calculation from the second database the complementary metadata needed for constructing and displaying the extrapolated world (Mex).

4. The method according to claim 3 , wherein the operation of extracting by calculation from the second database the complementary metadata needed for constructing and dynamically displaying the extrapolated world (Mex) depends on the pilot making a request.

5. The method according to claim 1 , wherein the complementary terrain elevation data is constituted at least in part by complementary maps with incorporated localization previously constructed and stored in a third database, the complementary maps with incorporated localization being constructed from the complementary metadata incorporating the navigation data of the rotorcraft as delivered by the on-board instrumentation simultaneously with sequentially capturing the complementary images, the prior construction of the complementary maps with incorporated localization being performed, providing the navigation assistance system has calculation capacity that is evaluated as being available in comparison with a predetermined calculation capacity threshold.

6. The method according to claim 1 , wherein during the operation of sequentially capturing the captured images, the method includes a step of selecting captured images by calculation in application of at least one predefined pertinence criterion relating to territorial continuity between the various captured territories picked up at a given instant by the various sets of cameras, the captured images that are deduced as not being pertinent relative to said pertinence criterion being eliminated prior to being processed by the navigation assistance system.

7. The method according to claim 6 , wherein at least one pertinence criterion is predefined depending on at least one of the following calculation parameters:
a first distance threshold between the rotorcraft and a captured territory that is picked up at a given instant by any of the sets of cameras; and
a second distance threshold between the various captured territories that are picked up at a given instant by the various sets of cameras of the rotorcraft.

8. The method according to claim 1 , wherein during the operation of sequentially capturing the captured images, the method includes a step of identifying at least one captured territory referred to as the “territory of interest”, by applying at least one predefined criterion of interest relating to the suitability of said territory of interest for being used by the rotorcraft, at the end of which identification step, data of interest is selectively incorporated in the metadata from which the captured images relating to said territory of interest is der

Assignees

• Airbus Helicopters

Inventors

• Belanger Nicolas
• Filias Francois-Xavier
• Pertuisot Geoffroy
• Damiani Nicolas

Classifications

• G01C21/1656

  with passive imaging devices, e.g. cameras · CPC title

• G06T7/593

  from stereo images · CPC title

• B64D43/00

  Arrangements or adaptations of instruments · CPC title

• G01C21/165

  combined with non-inertial navigation instruments · CPC title

• G01C21/005 Primary

  with correlation of navigation data from several sources, e.g. map or contour matching (G01C21/30 takes precedence) · CPC title