DEVICE AND METHOD FOR MEASURING DYNAMIC PARAMETERS OF AN AIRCRAFT PROGRESSING OVER AN AIRPORT ZONE

• US 20080177427A1
• Filed: 01/18/2008
• Published: 07/24/2008
• Est. Priority Date: 01/19/2007
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: MARTY, Nicolas, Meunier, Hugues, Francois, Gilles
• Granted Patent: US 8,073,584 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/20061 Hough transform
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/269 using gradient-based methods
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G08G 5/065 Navigation or guidance aids, e.g. for taxiing or rolling

Abstract

The invention relates to a device for measuring dynamic parameters of an aircraft progressing over an airport zone. The aircraft is in the phase of rolling along a traffic lane. The traffic lane comprises ground markings and notably a center line. The device includes at least one means for acquiring images (101), and means (102) for measuring the deviation of the aircraft with respect to the center line on the basis of the acquired images.

Claims

1. A device for measuring dynamic parameters of an aircraft progressing over an airport zone, the aircraft being in a phase of rolling along a traffic lane, the traffic lane comprising ground markings and notably a center line, the device comprises:

at least one means for acquiring images,

means for measuring the deviation of the aircraft with respect to the center line on the basis of acquired images, said means for measuring the deviation of the aircraft with respect to ground markings on the basis of said acquired images comprising;

means for calculating the coordinates of a first straight line supporting the direction of the center line, and

means for calculating an angular deviation XTK between said first straight line and a second straight line supporting the direction of the current trajectory of the aircraft and for calculating a lateral deviation XTE between the first and the second straight line.

means for measuring speed and position of said aircraft on the basis of said acquired images, said speed and position measuring means comprising;

means for recognizing ground marking elements on the basis of the acquired images,

means for correlating the recognized ground marking elements with referenced elements in an airport database, means for consolidating the speed and position calculated with speed and position estimated by other measuring equipment.

2. The device according to claim 1, wherein the means for acquiring images is composed of at least one radar.

3. The device according to claim 1, wherein the means for acquiring images is composed of at least one LIDAR.

4. The device according to claim 1, wherein the means for acquiring images is composed of at least one camera.

5. The device according to claim 1, wherein the means for measuring speed and position of the aircraft on the basis of said acquired images furthermore comprise:

means for measuring the movement of the aircraft,

means for estimating the speed of the aircraft.

6. The device according to claim 1, wherein it further comprising means for aiding surface navigation.

7. The device according to claim 1, wherein it further comprising display means.

8. The device according to claim 1, wherein it further comprising means of guidance of the aircraft.

9. A method for measuring dynamic parameters of an aircraft progressing over an airport zone, comprising the following steps:

calculating polar coordinates (r,θ

) of a first straight line supporting the direction of the center line, in an acquired image, the calculation of the polar coordinates (r,θ

) of the first straight line comprising the following steps;

detecting straight lines in the acquired image, grouping of said straight lines into sets according to their direction,

if several sets of different directions are created, the choice of a direction to be followed by the aircraft and the calculation of the coordinates of a straight line supporting said direction in a first image reference frame.

calculating an angular deviation XTK between said first straight line and a second straight line supporting the direction of the current trajectory of the aircraft and the calculation of a lateral deviation XTE between the first and the second straight line.

10. The method for measuring dynamic parameters of an aircraft progressing over an airport zone according to claim 9, wherein the step of detecting the straight lines comprises the following steps:

calculating a black and white binary image (I_B) containing solely the contours of the acquired image (I),

the application of an algorithm for extracting lines to the black and white binary image (I_B), making it possible to obtain a third grey level image (I_H),

estimating a number of straight lines (n) to be detected in the black and white binary image (I_B),

the search for local maxima in the third image (I_H),

determining the straight lines exhibiting the largest probability of occurrence in the black and white binary image (I_B), on the basis of the local maxima of the third image (I_H).

11. The method for measuring dynamic parameters of an aircraft progressing over an airport zone according to claim 9, wherein the step of calculating the angular deviation XTK and lateral deviation XTE comprises the following steps:

calculating two parameters (a₁,b₁) of the first straight line in the image reference frame on the basis of the polar coordinates (r,θ

) of said first straight line,

calculating a first series of points (LP₁) on the basis of the two parameters (a₁,b₁),

projecting, in an airplane reference frame, of the first series of points (LP₁) to obtain a second series of points (LP₂),

calculating two parameters (a₂,b₂) of a second straight line in the airplane reference frame passing through the second series of points (LP₂),

calculating the angular deviation XTK and lateral deviation XTE on the basis of the two parameters (a₂,b₂).

12. The method for measuring dynamic parameters of an aircraft progressing over an airport zone according to claim 9, further comprising a preprocessing step comprising the following steps:

applying a filter to the acquired image (I), to obtain a first less noisy filtered image (I_F),

applying a filter of Gaussian Laplacian type to the first filtered image (I_F), to obtain a second filtered image (I_L) where the contours are enhanced.

13. The method for measuring dynamic parameters of an aircraft progressing over an airport zone according to claim 9, wherein it further comprising a ground speed estimation and obstacle detection step comprising the following steps:

acquiring and storing a first image (I_t-1),

acquiring a second image (I_t),

calculating optical fluxes on the basis of the first image (I_t-1) and of the second image (I_t),

detecting a square encompassing an obstacle, on the basis of the optical fluxes,

estimating the speed on the basis of the square encompassing the obstacle,

determining the characteristics of the obstacle, comprising the distance between the aircraft and the obstacle D, the azimuth or bearing of the obstacle ρ and

the height of the obstacle H.