METHOD AND DEVICE FOR GENERATING A YAW SPEED ORDER FOR AN AIRCRAFT DURING A TAXIING

• US 20090150010A1
• Filed: 12/08/2008
• Published: 06/11/2009
• Est. Priority Date: 12/11/2007
• Status: Active Grant

• Current Assignee: Airbus Operations SAS (Airbus SE)
• Original Assignee: Airbus France
• Inventors: Scacchi, Pierre, Villaume, Fabrice
• Granted Patent: US 8,214,090 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: G05D 1/0083 to help an aircraft pilot in the rolling phase
• CPC Class Codes: G08G 5/065 Navigation or guidance aids, e.g. for taxiing or rolling

Abstract

The device (1) comprises means (7A) for calculating a yaw rate on the basis of measured current lateral and longitudinal speeds, as well as on the basis of a current curvature, of a current lateral deviation and of a current angular deviation, which are calculated previously, said yaw rate allowing the aircraft to follow laterally a ground rolling trajectory.

Claims

1. A method of generating a yaw rate command for an aircraft (A) rolling on the ground along a trajectory (TR), according to which method the following successive steps are carried out in a repetitive and automatic manner:

a) the current position, the current heading, the current lateral speed, and the current longitudinal speed of said aircraft (A) are measured;

b) a current curvature at a current target point (H) of the trajectory (TR) is determined on the basis of said trajectory (TR) and of said measured current position;

c) a current lateral deviation (yc) is determined on the basis of said trajectory (TR) and of said measured current position;

d) a current angular deviation (ψ

c) is determined on the basis of said trajectory (TR) and of said measured current heading; and

e) a yaw rate which represents said yaw rate command allowing the aircraft (A) to follow said trajectory (TR) is calculated on the basis of said measured current lateral and longitudinal speeds, as well as on the basis of said current curvature, of said current lateral deviation (yc) and of said current angular deviation (ψ

c),

wherein in step e), said yaw rate command rc is calculated with the aid of the following expression;

rc=(tgβ

·

Vx−

Vy)/LRA

in which;

Vx is the measured current longitudinal speed of the aircraft (A);

Vy is the measured current lateral speed of the aircraft (A);

LRA is a parameter illustrating the longitudinal wheelbase of the aircraft (A); and

β

is an angular parameter.

2. The method as claimed in claim 1, wherein in step b):

a current element (Ec) of said trajectory (TR) comprising a series of successive elements (E1 to En) is determined on the basis of said trajectory (TR) and of said measured current position;

a current target point (H) is determined on this current element (Ec), by taking account of a control point (O) of the aircraft (A) and of said current position; and

the curvature of said current element (Ec) at said current target point (H) is determined so as to obtain said current curvature.

3. The method as claimed in claim 1,

wherein in step c), said current lateral deviation (yc) is determined as the distance between a control point (0) of the aircraft (A) and a current target point (H) of the trajectory (TR).

4. The method as claimed in claim 1,

wherein in step d), said current angular deviation (ψ

c) is determined as the angular deviation between the current heading of the aircraft (A) and the tangent to the trajectory at the level of a current target point (H).

5. The method as claimed in claim 1, wherein said parameter β

depends on the current curvature, on the current lateral deviation (yc), and on the current angular deviation (ψ

c).

6. The method as claimed in claim 1,

wherein:

in step a), the current yaw rate of the aircraft (A) is measured;

a predicted curvature is determined on the basis of said trajectory (TR) and of said measured current position of the aircraft (A); and

said parameter β

is calculated on the basis of the current curvature, the current lateral deviation (yc), the current angular deviation (ψ

c), the current yaw rate, and the predicted curvature.

7. The method as claimed in claim 6,

wherein said predicted curvature corresponds to the curvature of the trajectory (TR) which is scheduled at a predetermined distance from the current position of the aircraft (A).

8. A procedure for the automatic lateral guidance of an aircraft rolling on the ground,

wherein the following series of successive operations is carried out in an automatic and repetitive manner:

A/ a yaw rate command is generated by implementing the method specified under claim 1;

B/ setpoints able to be applied to control means (25) which act on the yaw motion of the aircraft (A) are calculated, said setpoints being such that, applied to said control means (25), the latter pilot the aircraft (A) laterally according to said yaw rate command; and

C/ the setpoints thus calculated are applied to said control means (25).

9. A device for generating a yaw rate command for an aircraft (A) rolling on the ground along a trajectory (TR), said device comprising:

means (2) for receiving said trajectory (TR);

means (3) for measuring the current position, the current heading, the current lateral speed, and the current longitudinal speed of said aircraft (A);

means (4) for determining, on the basis of said trajectory and of said measured current position, a current curvature at a current target point (H) of the trajectory (TR);

means (5) for determining, on the basis of said trajectory and of said measured current position, a current lateral deviation (yc);

means (6) for determining, on the basis of said trajectory and of said measured current heading, a current angular deviation (ψ

c); and

means (7A, 7B) for determining, on the basis of said measured current lateral and longitudinal speeds, as well as on the basis of said current curvature, of said current lateral deviation (yc) and of said current angular deviation (ψ

c), a yaw rate which represents said yaw rate command allowing the aircraft (A) to follow said trajectory (TR),

wherein said means (7A, 7B) for determining said yaw rate are formed so as to calculate said yaw rate command rc with the aid of the following expression;

rc=(tgβ

·

Vx−

Vy)/LRA

in which;

Vx is the measured current longitudinal speed of the aircraft (A);

Vy is the measured current lateral speed of the aircraft (A);

LRA is a parameter illustrating the longitudinal wheelbase of the aircraft (A); and

β

is an angular parameter.

10. A system for the automatic lateral guidance of an aircraft rolling on the ground,

which comprises:

a device (1) such as that specified under claim 9, for generating a yaw rate command;

control means (25) which act on the yaw motion of the aircraft;

means (26) for calculating setpoints able to be applied to said control means (25), said setpoints being such that, applied to said control means (25), the latter pilot the aircraft (A) laterally according to said yaw rate command; and

means (28) for applying the setpoints thus calculated to said control means (25).