Method for constructing a trajectory of an aircraft by state vector

• US 8,930,130 B2
• Filed: 07/24/2013
• Issued: 01/06/2015
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Courteville, Romain, Barnetche, Bertrand
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): BOOMER, JEFFREY C
• Application Number:
  US13/950,187
• Publication Number:
  US 20140032095A1
• Time in Patent Office: 531 Days
• Field of Search: None
• US Class Current: 701/400
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G05D 1/101 specially adapted for aircraft
• CPC Class Codes: G08G 5/0034 Assembly of a flight plan
• CPC Class Codes: G08G 5/0039 Modification of a flight plan

Abstract

A method for constructing a flight trajectory of an aircraft, comprises a step of computing a sequence of state vectors (E_i) representing the trajectory of the aircraft; a state vector (E_i+1) being determined on the basis of the state vector (E_i) preceding it by means of: a step of computing the speed components (V_i+1), consisting in determining: a flight setpoint, by selecting an objective navigation point, a joining strategy adapted to the flight setpoint and to the flight domain (D_V) by means of a predefined library (L_Sr) of joining strategies, a manoeuvre by means of the flight domain (D_V), making it possible to follow the joining strategy towards the flight setpoint; a step of computing the other components of the state vector (E_i+1), on the basis of the components of the speed vector (V_i+1) and of the preceding state vector (E_i).

Claims

1. A computer implemented method for constructing a flight trajectory of an aircraft, deployed in a flight management system, said flight management system configured to determine, on the basis of a flight plan advised by the pilot, an objective navigation point sequence (SPNO), an objective navigation point being characterized at least by a geographical position, and configured to determine a flight domain (D_v) consisting of a set of parameters defining an aerodynamic behaviour of the aircraft, said flight trajectory being defined as a sequence of state vectors, the method comprising two successive steps:

first computing, with the flight management system, state vectors representing the trajectory of the aircraft;

the state vectors having as components at least a time (t_i), a geographical position (X_i,) of the aircraft and components of a speed vector (V_i) of the aircraft;

a state vector (E_i+1) being determined on a basis of the preceding state vector (E_i) preceding it in a sequence by;

computing the components of a following speed vector (V_i+1), including;

determining a flight setpoint, by selecting an objective navigation point from the objective navigation point sequence (S_PNO), then

determining a joining strategy adapted to the flight setpoint and to the flight domain (D_v) by means of a predefined library (L_sr) of joining strategies, then

determining a manoeuvre by means of the flight domain (D_v), allowing the aircraft to follow the joining strategy towards the flight setpoint, and

second computing, with the flight management system, other components of the state vector (E_i+1), on a basis of the components of the following speed vector (V_i+1) and components of the preceding state vector (E_i) in the sequence proceeding it in the sequence.

2. The method according to claim 1, wherein the computation of the flight setpoint comprises computation steps comprising:

associating acknowledgement conditions with the flight setpoint of the preceding state vector (E_i),

determining whether the acknowledgement conditions are satisfied,

determining the flight setpoint of the state vector (E_i+1) as being;

the flight setpoint of the preceding state vector (E_i) in the case of unsatisfied acknowledgement conditions, and

a next objective navigation point in the sequence (SPNO) in the case of satisfied acknowledgement conditions;

the acknowledgement conditions comprising at least one threshold of distance between a geographical position of the preceding state vector (E_i) and of its flight setpoint.

3. The method according to claim 1, wherein the computation of the joining strategy comprises computation steps comprising:

devising a list of joining strategies from among a predefined library (L_Sr) of joining strategies, as a function of the preceding state vector (E_i) and of the flight setpoint,

grading and prioritizing each of the joining strategies of the list as a function of the preceding state vector (E_i), of the flight setpoint and of the flight domain (D_v), and

selecting the joining strategy of highest priority.

4. The method according to claim 1, wherein the geographical position of a state vector (E_i) is characterized by three components (X_i), comprising a latitude, a longitude and altitude, which are defined in a datum related to a geoid of WGS 84 type.

5. The method according to claim 1, wherein the speed vector of a state vector (E_i) is characterized by three components (V_i), comprising a norm, a slope angle with respect to a constant altitude trajectory, and a course angle with respect to geographical North.

6. The method according to claim 1, wherein the state vectors (E_i) also have as component a mass (m_i) of the aircraft.

7. The method according to claim 6, wherein the mass component (m_i+1) of a state vector (E_i+1) is determined by a fuel consumption computation.

8. The method according to claim 1, wherein the state vectors (E_i) also have as component a magnitude characteristic of wind in an environment of the aircraft, or a magnitude characteristic of an aerodynamic configuration of the aircraft.

9. The method according to claim 1, wherein a geographical position components (X_i+1) of a state vector (E_i+1) are determined by integration on a basis of its speed components (V_i+1) and of the preceding state vector (E_i).

10. The method according to claim 8, wherein the geographical position components (X₁₊₁) of a state vector (E₁₊₁) are determined by an Euler scheme by means of the following relation:

X_i+1=X_i+½

*(V_i+V_i+1)*(t_i+1−

t_i)

in which t_i+1, X_i+1, V_i+1 are the time, geographical position and speed components of the state vector E_i+1; and

t_i, X_i, V_i are the time, geographical position and speed components of the preceding state vector E_i.

11. A flight management system comprising instructions of codes making it possible to perform the steps of the computer implemented method for constructing a flight trajectory of an aircraft according to claim 1.