Avoidance method and system for an aircraft
Disclosed is a method and system for avoiding collision between an aircraft A and an intruder aircraft. The method and system involve determining avoidance presets to avoid a collision between the aircraft A and the intruder aircraft, in which the avoidance presets comprise a vertical speed preset. The presets are determined from avoidance information received from an anticollision system, and the determined avoidance presets are transmitted to at least one guidance device that guides the aircraft A based on the avoidance presets.
1. A method of avoiding collision between an aircraft A and an intruder aircraft, while avoiding abrupt variations in load factor, said method comprising the steps of:
a) determining avoidance presets to avoid a collision between the aircraft A and the intruder aircraft, wherein said avoidance presets are determined from avoidance information received from an anticollision system configured for monitoring trajectory of the intruder aircraft in proximity to the aircraft A and producing aircraft collision avoidance information to implement in-flight avoidance between the intruder aircraft and the aircraft A, wherein the avoidance presets are expressed in terms of load factor; and
b) transmitting deflection orders, by an automatic guidance unit, to guide the aircraft A to avoid collision with the intruder aircraft, with the deflection orders being based on the determined avoidance presets,
wherein in step a),
the avoidance presets are determined by a calculation unit configured for: i) determining first resets expressed in terms of vertical seed for avoiding collision between the aircraft A and the intruder aircraft, and ii) transforming the determined first presets into the avoidance presets,
wherein the determined first presets:
are determined from the avoidance information received by the calculation unit from the anticollision system, and
are transformed into said avoidance presets by:
calculating a difference between a first determined vertical speed preset and a measured vertical speed of the aircraft A,
applying a filter to filter variations in the calculated difference over time, and
multiplying the filtered calculated difference by a gain dependent on air speed of the aircraft A.
2. The method of claim 1 , wherein a flight director unit is configured for implementing a display mode to display information representative of the avoidance presets.
3. The method of claim 1 , wherein the first presets are determined to be at substantially zero vertical speed, while complying with the avoidance information.
4. The method of claim 1 , wherein the first presets are determined to minimize deviation between an avoidance trajectory of the aircraft A and an initial trajectory.
5. The method of claim 1 , wherein the avoidance presets comprise auxiliary avoidance presets for avoiding collision in a lateral plane.
6. The method of claim 1 , wherein the automatic guidance unit is configured to trigger an automatic guidance mode when an automatic pilot is engaged.
7. The method of claim 6 , wherein the automatic guidance mode is triggered by pilot actuation of an actuation unit.
8. The method of claim 6 , wherein the automatic guidance mode is triggered by an alarm.
9. The method of claim 6 , wherein the automatic guidance mode is configured to be stopped by pilot actuation of an actuation unit.
10. The method of claim 6 , wherein the automatic guidance mode is configured to be triggered automatically when a pilot engages the automatic pilot.
11. The method of claim 1 , wherein the automatic guidance unit that transmits the orders to guide the aircraft A is actuated to trigger a guidance mode and an automatic pilot is engaged.
12. The method of claim 1 , wherein the automatic guidance unit that transmits the orders to guide the aircraft A is actuated to trigger a guidance mode and a corrective alarm is replaced by a preventive alert while the guidance mode remains operational.
13. The method of claim 1 , wherein the automatic guidance unit that transmits the orders to guide the aircraft A is actuated to trigger a guidance mode and the guidance mode is stopped when:
a pilot disengages an automatic pilot;
the pilot triggers another guidance mode; or
the anticollision system emits an end-of-alarm signal.
14. The method of claim 1 , wherein the determined avoidance presets are transmitted to a flight director unit configured for implementing a display mode to display information representative of the avoidance presets, when an automatic pilot is engaged and when a display mode is triggered to display the information.
15. The method of claim 13 , wherein the displayed information represents the determined avoidance presets.
16. The method of claim 2 , wherein the flight director unit is configured to implement the display mode to:
display a message to warn a pilot of an alarm; and
the display mode is triggered by actuation of an actuation unit by the pilot.
17. The method of claim 13 , wherein the display mode is triggered by an emission of an alarm.
18. The method of claim 13 , wherein the display mode is stopped by actuation of an actuation unit by a pilot.
19. The method of claim 13 , wherein the display mode is triggered by a pilot engaging the flight director unit.
20. The method of claim 13 , wherein the display mode is triggered during emission of an alarm.
21. The method of claim 13 , wherein the display mode is triggered and a corrective alarm is replaced by a preventive alert while the display mode remains operational.
22. The method of claim 6 , wherein when a pilot disengages the at least one automatic guidance unit, the triggered guidance mode is exited, and a display mode is triggered on a flight director unit.
23. The method of claim 1 , wherein a preventative alert is emitted under at least one of the following conditions:
the anticollision system is initially in a guidance mode in which the guidance mode varies vertical speed of the aircraft, and a vertical speed maintain mode is engaged to guide the aircraft at current vertical speed; and
the anticollision system is initially in a guidance mode in which the guidance mode guides the aircraft at a constant vertical speed, and the preventative alert is emitted while the guidance mode is maintained.
24. The method of claim 1 , further comprising a step of emitting a corrective alarm and guiding the aircraft A toward a vertical speed target.
25. The method of claim 5 , wherein an alert is emitted under at least one of the following conditions:
the anticollision system is in a lateral guidance mode for avoiding collision in the lateral plane; and
a mode for maintaining a current heading is engaged when the anticollision system is not in the lateral guidance mode.
26. The method of claim 1 , further comprising a step of emitting an alarm and engaging thrust engines of the aircraft in a speed maintain mode.
27. The method of claim 1 , further comprising a step of emitting a preventative alert during guidance and emitting an end-of-alarm signal to exit from guidance based on the avoidance presets.
28. The method of claim 1 , further comprising a step of emitting a corrective alarm during guidance and emitting an end-of-alarm signal to exit from guidance based on the avoidance presets.
29. The method of claim 27 , further comprising the steps of:
engaging a longitudinal vertical speed maintain mode and an altitude capture mode to capture a target altitude to rejoin initial trajectory; and
maintaining a lateral guidance mode.
30. The method of claim 1 , further comprising a step of reinitializing guidance of the aircraft A based on a change of alarm status.
31. The method of claim 1 , further comprising a step of emitting a preventative alert during guidance and maintaining an altitude capture mode.
32. The method of claim 1 , further comprising the steps of:
emitting a corrective alarm,
enabling an altitude capture mode, and
disabling the altitude capture mode when vertical speed is in a prohibited vertical speed domain.
33. The method of claim 1 , wherein the first vertical speed preset is transformed by the calculation unit according to:
NZ com= K ·( VZ current− VZ target)in which:
NZcom represents a value of a commanded load factor, which is used to guide the aircraft A;
VZcurrent is a value of current vertical speed of the aircraft A;
VZtarget is a target vertical speed value; and
K is a variable dependent on a current speed of the aircraft A.
34. The method of claim 1 , further comprising a step of emitting a preventative alert and presenting an enabled avoidance mode to a pilot.
35. The method of claim 1 , further comprising a step of emitting a corrective alarm and presenting an enabled avoidance mode to a pilot.
36. An aircraft collision avoidance system for avoiding collision between an aircraft A and an intruder aircraft, while avoiding abrupt variations in load factor, said system comprising:
an anticollision system configured for measuring trajectory of the intruder aircraft in proximity to the aircraft A and producing aircraft collision avoidance information to implement in-flight avoidance between the intruder aircraft and the aircraft A;
a calculation unit for determining avoidance presets to avoid collision between the aircraft A and the intruder aircraft, wherein the avoidance presets are expressed in terms of load factor, with the calculation unit being configured for:
i) determining first presets expressed in terms of vertical speed for avoiding collision between the aircraft A and the intruder aircraft, wherein the first presets are determined from the avoidance information received from the anticollision system, and
ii) transforming the first presets into the avoidance presets by:
calculating a difference between a first determined vertical speed preset and a measured vertical speed of the aircraft A,
applying a filter to filter variations in the calculated difference over time, and
multiplying the filtered calculated difference by a gain dependent on air speed of the aircraft A; and
an automatic guidance unit, connected to said calculation unit, in which the automatic guidance unit transmits deflection orders to guide the aircraft A to avoid collision with the intruder aircraft based on the determined avoidance presets.
37. The aircraft collision avoidance system of claim 36 , further comprising flight director unit configured for implementing a display mode to display the avoidance presets.
38. The aircraft collision avoidance system of claim 36 , further comprising a pilot actuation unit configured for triggering the automatic guidance unit to guide the aircraft A based on the avoidance presets.
39. The aircraft collision avoidance system of claim 36 , wherein the calculation unit is an automatic pilot.
40. The aircraft collision avoidance system of claim 36 , further comprising a display unit configured to display a warning message.
41. The aircraft collision avoidance system of claim 36 , wherein the automatic guidance unit is configured to transmit the deflection orders to control surfaces of the aircraft A to guide the aircraft A.