Autonomous and automatic landing method and system

Patent metadata

Field	Value
Publication number	US-9260180-B2
Application number	US-201414339220-A
Country	US
Kind code	B2
Filing date	Jul 23, 2014
Priority date	Jul 24, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A system and method are disclosed for automatic landing of an aircraft on a landing runway, including an on-board video camera intended to take images of the ground, image processor to extract from these images visual features of the landing runway, guidance system determining guidance commands of the aircraft to bring it into a nominal approach plane and to align it with the axis of the landing runway, from the respective positions of the visual features of the landing runway, in at least one of the images, where the guidance commands are supplied to a flight control computer.

First claim

The invention claimed is:

1. A system for automatic landing of an aircraft on a landing runway, the system comprising:
at least one on-board video camera on board the aircraft, wherein the on-board video camera is configured to take a series of successive images of the ground;
an image processor configured to extract from the images visual features of the landing runway; and
a guidance system configured to:
determine a horizon line for a first image of the series of successive images;
determine a respective demand position for an axis (Δ) of the landing runway and a touchdown point (P) on the landing runway in the first image to bring the aircraft into a nominal approach plane and to align the aircraft with the axis of the landing runway, wherein the demand position of the axis of the landing runway is based on a median vertical axis of the image, and wherein the demand position of the touchdown point is the point of intersection between the median vertical axis and a line parallel to the horizon line and located under the horizon line at a demand distance from the horizon line;
estimate the distance between the positions of the visual features and the demand positions of the visual features in the first image; and
determine guidance commands of the aircraft based on the estimated distances between the positions of the visual features and the demand positions of the visual features in the first image to bring the visual features to their respective demand positions in the first image.

2. The automatic landing system of claim 1 , wherein the guidance system is configured to estimate the distance between the axis of the runway and the median vertical axis of the image by distance d Ω separating vanishing point Ω and point of intersection H between the median vertical axis of the image and the horizon line, and angle θ r between the axis of the runway and a horizontal axis of the image.

3. The automatic landing system of claim 2 , wherein the demand position for the touchdown point is equal to d P,c =f·(tan(θ+δ 0 )−tan(θ)) where f is the focal distance of the camera, θ is the aircraft's pitch angle and δ 0 is the angle between the nominal approach plane and the horizontal plane.

4. The automatic landing system of claim 2 , wherein the guidance system is configured to determine the guidance commands of the aircraft by:
{dot over (φ)} c =k 1 tan(θ r −θ r,c )+ k 2 Arc tan( d Ω −d Ω,c )+ k 3 φ+k 4 {dot over (φ)}

Nz c =k 5 ( d P −d P,c )+ k 6 {dot over (d)} P

where {dot over (φ)} c is the demand roll speed, Nz c is the demand load factor, φ and {dot over (φ)} are respectively the instantaneous roll angle and roll speed of the aircraft, and k i , i=1, . . . , 6 are predetermined real numbers, θ r,c =0 and d Ω,c is a set point value.

5. The automatic landing system of claim 4 , wherein demand value d Ω,c is an increasing function of the side wind speed, and zero if no such wind is present.

6. The automatic landing system of claim 1 , wherein the image processor is configured to identify at least one landing runway in one image.

7. The automatic landing system of claim 6 , comprising a display device to display the images of the on-board video camera, coupled to a user interface, wherein the user interface enables a visual indicator of a first landing runway to be selected from multiple landing runways in an image displayed by the display device.

8. The automatic landing system of claim 6 , wherein the image processor is configured to determine the axis of the landing runway and the touchdown point on the landing runway.

9. The automatic landing system of claim 1 , comprising a display device to display the images of the video camera, coupled to a user interface, where the user interface enables the axis of the landing runway to be designated on the image, together with a touchdown point on this runway.

10. A method performed by a guidance computer for automatic landing of an aircraft on a landing runway, the method comprising:
taking, using an on-board video camera, a successive series of images of the ground;
using image processing software to extract from the images visual features of the landing runway;
determining a horizon line for a first image of the series of successive images;
determining a respective demand position for an axis (Δ) of the landing runway and a touchdown point (P) on the landing runway in the first image to bring the aircraft into a nominal approach plane and to align the aircraft with the axis of the landing runway, wherein the demand position of the axis of the landing runway is based on a median vertical axis of the image, and wherein the demand position of the touchdown point is the point of intersection between the median vertical axis and a line parallel to the horizon line and located under the horizon line at a demand distance from the horizon line;
estimating the distance between the positions of the visual features and the demand positions of the visual features in the first image; and

determining guidance commands of the aircraft based on the estimated distances between the positions of the visual features and the demand positions of the visual features in the first image to bring the visual features to their respective demand positions of the visual features in the first image.

Assignees

• Airbus Operations Sas

Inventors

• Puyou Guilhem
• Gibert Victor
• Perrin Fabien

Classifications

• B64C13/16 Primary

  actuated automatically, e.g. responsive to gust detectors · CPC title

• G08G5/54 Primary

  for approach or landing · CPC title

• G05D1/0676

  specially adapted for landing · CPC title

• G08G5/025

  Physics · mapped topic