Method for guiding an aircraft during a convoy flight
First Claim
1. A process for guiding a so-called slave aircraft (2) in the context of a convoy flight, behind another so-called master aircraft (1), on one and the same predetermined trajectory and with a preset minimum separation distance DSEP, characterized in that it consists in giving the calculated air speed VCAS,S of the slave aircraft (2) an initial value VCASO,S, in periodically deducing the distance separating the slave aircraft (2) from the master aircraft (1) from the geographical position of the slave aircraft (2) and from that of the master aircraft (1) at one and the same instant, and from the known shape of the trajectory followed by the master (1) and slave (2) aircraft, then in periodically correcting the calculated air speed VCAS,S of the slave aircraft (2) by modifying it with a corrective term E derived from the discrepancy noted between the measured separation distance D and the preset minimum separation distance DSEP, this guidance process being defined by a recurrence relation of the form:
-
Δ
t being the periodicity of the correction, DM and DSEP values updated at the instant (t0+(k−
1)Δ
t).
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Accused Products
Abstract
The invention relates to compliance with the safety distances between aircraft travelling, in a queue, one behind the other, through a prescribed air corridor. It is more especially concerned with a process allowing an aircraft knowing its position and those of the various aircraft flying in its close vicinity, for example by virtue of the ADS-B system, to manage by itself its separation distance with respect to another aircraft taken as reference. Such a process is an aid afforded to the crew of an aircraft and to the control authority regulating the traffic in the relevant air corridor.
34 Citations
21 Claims
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1. A process for guiding a so-called slave aircraft (2) in the context of a convoy flight, behind another so-called master aircraft (1), on one and the same predetermined trajectory and with a preset minimum separation distance DSEP, characterized in that it consists in giving the calculated air speed VCAS,S of the slave aircraft (2) an initial value VCASO,S, in periodically deducing the distance separating the slave aircraft (2) from the master aircraft (1) from the geographical position of the slave aircraft (2) and from that of the master aircraft (1) at one and the same instant, and from the known shape of the trajectory followed by the master (1) and slave (2) aircraft, then in periodically correcting the calculated air speed VCAS,S of the slave aircraft (2) by modifying it with a corrective term E derived from the discrepancy noted between the measured separation distance D and the preset minimum separation distance DSEP, this guidance process being defined by a recurrence relation of the form:
-
Δ
t being the periodicity of the correction, DM and DSEP values updated at the instant (t0+(k−
1)Δ
t).- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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8. The process as claimed in claim 7, characterized in that the safety coefficient k′
- is taken equal to 0.8.
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9. The process as claimed in claim 7, characterized in that a hysteresis phenomenon is introduced around the effective tolerance margin Δ
- Le by giving the latter, when it has just been overshot and for as long as it is overshot, a reduced value deduced from the preset tolerance margin Δ
L, by applying a positive hysteresis coefficient k″
of less than the safety coefficient k.
- Le by giving the latter, when it has just been overshot and for as long as it is overshot, a reduced value deduced from the preset tolerance margin Δ
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10. The process as claimed in claim 9, characterized in that the hysteresis coefficient k″
- is taken equal to 0.5.
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11. The process as claimed in claim 1, characterized in that the corrective term E is taken proportional to the discrepancy noted between the measured separation distance D and the preset minimum separation distance DSEP with a coefficient of proportionality p taken equal to:
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12. The process as claimed in claim 11, characterized in that the consistency coefficient M is taken equal to:
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kts being a speed in knots and Nm a nautical mile.
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13. The process as claimed in claim 1, characterized in that the measured separation distance DM is the horizontal component of the effective separation distance.
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14. The process as claimed in claim 1, characterized in that the measured separation distance DM separating, at a given instant, the slave aircraft (2) from the master aircraft (1) on a rectilinear trajectory, is derived from the locations of the master (1) and slave (2) aircraft by means of the relation:
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15. The process as claimed in claim 1, characterized in that the measured separation distance DM separating, at a given instant, the slave aircraft (2) from the master aircraft (1) while the slave aircraft (2) is situated on a rectilinear part, with heading χ
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p, of the trajectory followed by the two aircraft, and the master airplane (1) on another rectilinear part, with heading χ
s, of this trajectory, which are joined together by an arc of a circle of radius r, starting at a point P1 marking the end of the rectilinear trajectory part traversed by the slave aircraft (2) and terminating at a point P2 marking the start of the rectilinear trajectory part traversed by the master aircraft (1), is taken equal to the sum of the distances separating the slave aircraft (2) from the point P1 and the point P2 from the master aircraft (1) plus the length L of the circular arc taken equal to;
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p, of the trajectory followed by the two aircraft, and the master airplane (1) on another rectilinear part, with heading χ
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16. The process as claimed in claim 1, characterized in that the separation preset distance DSEP is deduced from a minimum timespan preset Δ
- T between the passings of the two aircraft (1, 2) through one and the same point of the trajectory by applying the relation;
- T between the passings of the two aircraft (1, 2) through one and the same point of the trajectory by applying the relation;
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17. The process as claimed in claim 1, characterized in that the separation preset distance DSEP is derived from a defining table giving it as a function of altitude.
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18. The process as claimed in claim 1, characterized in that the separation preset distance DSEP is a distance preset given by an air controller.
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19. The process as claimed in claim 1, characterized in that the location of the master aircraft (1) is transmitted in a cooperative manner by the latter to the slave aircraft (2) by means of an ADS-B system.
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20. The process as claimed in claim 1, characterized in that the slave aircraft (2) acquires the location of the master aircraft (1) by means of an onboard radar.
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21. The process as claimed in claim 1, characterized in that the slave aircraft (2) acquires the location of the master aircraft (1) from a ground-based locating station.
Specification