Aircraft flight control method and system

Patent metadata

Field	Value
Publication number	US-10386859-B2
Application number	US-201715726641-A
Country	US
Kind code	B2
Filing date	Oct 6, 2017
Priority date	Oct 11, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

A system including a set of computation modules configured to be utilized for computation of gains of at least one piloting law relative to at least one piloting axis of the aircraft and a data capture unit for capturing in at least one computation unit associated with a given piloting axis of the aircraft first values illustrating aerodynamic coefficients of the aircraft and second values defining delay and filter characteristics of the control chain relative to the given piloting axis, the computation unit being configured to compute the gains of the piloting law utilizing at least a part of the set of computation modules and the computation unit computing inputs intended for at least one actuator of a control surface adapted to control the aircraft relative to the given piloting axis in accordance with a corresponding current control value.

First claim

The invention claimed is:

1. A method for controlling the flight of an aircraft with respect to at least one piloting axis of the aircraft, said aircraft being provided with an electrical flight control system, comprising the following steps:
integrating into at least one processing unit of the flight control system of the aircraft a generic set of parameter computation modules in an integration step, at least some of said computation modules being intended to be used for computation of gains of at least one piloting law relative to at least one given piloting axis, said generic set of computation modules utilizing first values illustrating aerodynamic coefficients of the aircraft and second values defining delay and filter characteristics of a control chain relative to the given piloting axis;
capturing by means of a data capture unit in at least one computation unit associated with the given piloting axis of the aircraft, in at least one data capture step, first values illustrating the aerodynamic coefficients of the aircraft and second values defining the delay and filter characteristics of the control chain relative to said piloting axis, said computation unit being configured to compute the gains of the piloting law utilizing at least a part of said generic set of computation modules, the control chain being linearized so as to make it possible to generate inputs intended for at least one actuator of a control surface adapted to control the aircraft relative to said piloting axis in accordance with at least one current control value of the aircraft by means of a controlled variable supplied in a raw state, the control chain being linearized and verifying the following equation:

δ
u

=

F
equi

·

(

K
uc

⁢

u
c

+

K
u

⁢
u

+

K

u
⁢

⁢
dot

⁢

s
·
u

+

K
ui

s

⁢

(

u
c

-
u

)

)

in which:
δ u is the movement of a control surface generated by this control chain;
F equi is a global filter illustrating the modelling of a filter and all of the delays and asynchronisms of the control chain and verifying the following equation:
F equi =pade( T, 2)* B ( s )

in which:
pade(T,2) is a second order Pade filter; and
B(s) is a second order Butterworth filter,
u c is the control value;
u is the non-filtered and non-delayed controlled variable;
s is the Laplace variable; and
K uc , K u , K udot and K ui are gains; and
at least one control step during a flight of the aircraft, comprising
entering into the computation unit said current control value generated by means of a data generation unit and computing the inputs for controlling said aircraft relative to said given piloting axis by means of said computation unit utilizing this current control value, the inputs computed in this way being transmitted to the actuator of the control surface, wherein the actuator of the control surface receives the transmitted inputs and is actuated as a function of the received inputs.

2. The method according to claim 1 , wherein at least some of said gains K uc , K u , K udot and K ui are determined from equations present in said generic set of computation modules.

3. The method according to claim 1 , wherein said generic set of parameter computation modules is utilized by a plurality of control steps to control the flight of the aircraft relative to at least two of the following three piloting axes of the aircraft:
the pitch axis;
the roll axis; and
the yaw axis.

4. The method according to claim 1 , wherein the control step comprises computing an input in the form of a deflection input δq of an elevator of the aircraft from a current control value Nz c corresponding to a load factor Nz that represents a position of a control column that can be actuated by a pilot of the aircraft using the following equation:

δ
⁢

⁢
q

=

F
equi

·

(

K
D

⁢

Nz
c

+

K
Nz

⁢
Nz

+

K
q

·
q

+

K
i

s

⁢

(

Nz
c

-
Nz

)

)

in which:
F equi is a global filter;
s is the Laplace variable;
K Nz , K q and K i are gains; and
K D is a precontrol term.

5. The method according to claim 4 , wherein said

Assignees

• Airbus Operations Sas

Inventors

• Delannoy Stéphane

Classifications

• B64C13/0421

  control sticks for primary flight controls · CPC title

• G05D1/0825

  using mathematical models · CPC title

• B64C13/503

  Fly-by-Wire · CPC title

• G05B11/42 Primary

  for obtaining a characteristic which is both proportional and time-dependent, e.g. P. I., P. I. D. · CPC title

• B64C13/506

  overriding of personal controls; with automatic return to inoperative position · CPC title