Method and device for lateral control of a taxiing aircraft

Patent metadata

Field	Value
Publication number	US-9604719-B2
Application number	US-201414167095-A
Country	US
Kind code	B2
Filing date	Jan 29, 2014
Priority date	Jan 30, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A device for lateral control of an aircraft includes a calculating unit for automatically applying, if conditions for turning of the aircraft are met, a symmetrical braking value at a brake assembly. Subsequently, in the course of the turn, the device automatically distributes this symmetrical braking value in differential braking between a braking device of the left main landing gear and a braking device of the right main landing gear of the aircraft. Distribution of the symmetrical breaking is performed as a function of current directional command orders in such a way as to maintain a constant overall braking level for, at least for directional command orders below a predetermined threshold.

First claim

What is claimed is:

1. A method of lateral control of an aircraft, said aircraft equipped with an orientable nose wheel provided with an orientation system, wherein, in event of a breakdown of the orientation system, said method implementing an emergency automatic asymmetrical braking, comprising:
receiving directional command orders relating to a command of an orientation of said nose wheel;
automatically determining braking orders for a brake assembly of the aircraft on a basis of said directional command orders, wherein the brake assembly comprises a first braking device for at least one left main landing gear and a second braking device for at least one right main landing gear and which is capable of generating a lateral movement of the aircraft about a vertical axis with an asymmetrical action,
wherein said braking orders are determined to generate a lateral movement on the aircraft which is substantially identical to the lateral movement which would have been generated by an application of said directional command orders to said nose wheel when they are applied to the brake assembly; and
automatically applying said braking orders to said brake assembly,
wherein the method also comprises:
automatically determining braking orders for the brake assembly of the aircraft on the basis of said directional command orders comprises automatically verifying whether conditions for turning the aircraft are met in the event of activation of the emergency automatic asymmetrical braking; and
if the conditions for turning the aircraft are met and for as long as the conditions are met:
automatically applying a symmetrical braking value at said brake assembly; and
automatically distributing the symmetrical braking value in differential braking between the first braking device of the left main landing gear and the second braking device of the right main landing gear as a function of current directional command orders, in such a way as to maintain a constant overall braking level, at least for directional command orders below a predetermined threshold;

wherein the symmetrical braking value is generated in the form of a symmetrical pressure (Ps);
wherein said symmetrical pressure (Ps) is combined with a commanded pressure (Pc), which is representative of said directional command orders, in order to form a high pressure (Ph) and a low pressure (Pb), of which one of the Ph or Pb is applied to the first braking device of the left landing gear and of which the other is applied to the second braking device of the right landing gear, as a function of the direction relative to said directional command orders; and
wherein Ps and Pc are combined such that, if Pc is greater or equal to twice Ps, then Ph is set equal to Pc and Pb is set equal to zero; and if Pc is less than twice Ps, then Ph is set equal to the sum of Ps and half of Pc and Pb is set equal to the difference between Ps and half of Pc.

2. The method according to claim 1 , wherein said symmetrical pressure (Ps) depends upon characteristics of the aircraft and is defined such that an associated asymmetrical braking reserve covers, while turning the aircraft, the resistive moment of landing gears of the aircraft, as well as orders below the predetermined threshold.

3. The method according to claim 1 , wherein the high pressure (Ph) and the low pressure (Pb) are calculated on the basis of the symmetrical pressure (Ps) and of the commanded pressure (Pc), with aid of the following expressions:
if Pc= 0, Ph=Pb=Ps;
if Pc< 2* Ps,Ph=Ps+Pc/ 2 and Pb=Ps−Pc/ 2; and
if Pc≧ 2* Ps,Ph=Pc and Pb= 0.

4. The method according to claim 1 , wherein the conditions for turning the aircraft are met when the following conditions are simultaneously met:
the emergency automatic asymmetrical braking is activated;
a ground speed of the aircraft is lower than a predetermined speed; and
a directional command order of said directional command orders is higher than a selected threshold value.

5. The method according to claim 1 , wherein, when the conditions for turning the aircraft are met, the symmetrical braking value is applied progressively over a predetermined length of time.

6. The method according to claim 1 , wherein, when the conditions for turning the aircraft are no longer met, and the symmetrical braking value continues to be applied for a predetermined duration, then the symmetrical braking is progressively cancelled over a predetermined length of time.

7. The method according to claim 1 , wherein said symmetrical braking value, representing an asymmetrical braking reserve, is combined with a thrust reserve, and said thrust reserve is applied to a mode of propulsion of the aircraft during turning of said aircraft.

8. A device for lateral control of an aircraft, said aircraft equipped with an orientable nose wheel provided with an orientation system, wherein said device includes, at least in order to implement emergency automatic asymmetrical braking in the event of breakdown of the orientation system:
a receiving device that is configured to receive directional command orders relating to a command of the orientation of said nose wheel;
a determining device that is configured to automatically determine, on a basis of said directional command orders, braking orders for a brake assembly of the aircraft, wherein the brake assembly comprises a first braking device for at least one left main landing gear and second braking device for at least one right main landing gear and which is capable of generating a lateral movement of the aircraft about a vertical axis with an asymmetrical action, said braking orders determined in such a way as to generate on the aircraft, when the braking orders are applied to the brake assembly, a lateral movement which is substantially identical to the lateral movement which would have been generated by an application of said directional command orders to said nose wheel; and
a first application device that is configured to automatically apply said braking orders to said brake assembly,
wherein said brake assembly further comprises a verification device that is configured to automatically verify, in the event of activation of the emergency automatic asymmetrical braking, whether conditions for turning the aircraft are met;
a second application device that is configured to automatically apply, if the conditions for turning the aircraft are met and for so long as the conditions are met, a symmetrical braking value at said brake assembly, then in the course of the turn automatically distributing this symmetrical braking value in differential braking between the first braking device of the left main landing gear and the second braking device of the right main landing gear, as a function of current directional command orders, in such a way as to maintain a constant overall braking level, at least for directional command orders below a predetermined threshold;
wherein the second application device is configured to generate the symmetrical braking value in the form of a symmetrical pressure (Ps);
wherein said symmetrical pressure (Ps) is combined with a commanded pressure (Pc), which is representative of said directional command orders, in order to form a high pressure (Ph) and a low pressure (Pb), of which one of the Ph or Pb is applied to the first braking device of the left landing gear and of which the other is applied to the second braking device of the right landing gear, as a function of the direction relative to said directional command orders; and
wherein Ps and Pc are combined such that, if Pc is greater or equal to twice Ps, then Ph is set equal to PC and Pb is set equal to zero; and if Pc is less than twice Ps, then Ph is set equal to the sum of Ps and half of Pc and Pb is set equ

Assignees

• Airbus Operations Sas

Inventors

• Mayolle Matthieu
• Acanfora Caroline
• Romana Louis-Emmanuel
• Fontan Julien

Classifications

• B64C25/48 Primary

  differentially operated for steering purposes · CPC title

• B64C25/50

  Steerable undercarriages; Shimmy-damping · CPC title

• B60T8/1703

  for aircrafts · CPC title

• B60T2201/16

  Curve braking control, e.g. turn control within ABS control algorithm · CPC title