Method and device for active control of the roll of an aircraft
View Patent ↗A control device a determination device for determining a roll objective, and a calculation device for calculating, on the basis of the roll objective, a deflection order which is applied exclusively to ailerons of the aircraft.
1. A method of active control of a roll of an aircraft, comprising:
a) generating a roll objective, which is expressed as a roll parameter related to the roll and which is applied to the aircraft;
b) determining effective values of parameters of the aircraft;
c) calculating a deflection order Sp on the basis of said roll objective and of said effective values; and
d) applying said deflection order δp exclusively to airfoils of the aircraft, which are efficient on a roll axis, so as to control the roll,
wherein in step c):
a first value is calculated on the basis of said roll objective; and
said deflection order δp is calculated on the basis of the first value and of said effective values which comprise the effective value of the roll rate, by using at least one integration function, and wherein
c1) a roll acceleration order is calculated on the basis of said roll objective; and
c2) said deflection order Sp is calculated with the aid of the following expressions:
{
δ
p
=
(
P
1
-
F
+
Δ
RMI
)
G
F
=
ρ
V
2
SlCl
2
I
G
=
ρ
V
2
Sl
(
∂
C
l
∂
δ
p
)
2
·
I
Δ
RMI
=
K
(
-
Peff
+
∫
(
F
+
G
δ
peff
-
Δ
RMI
)
·
ⅆ
t
)
in which:
P1 represents said roll acceleration order;
ρ is the density of the air;
V is the speed of the aircraft;
S is a reference area of the aircraft;
l is a reference length of the aircraft;
Cl represents a roll coefficient;
I represents the roll inertia of the aircraft
∂Cl/∂δp represents an effectiveness coefficient;
K represents a predetermined coefficient;
Peff represents the effective value of the roll rate;
∫ illustrates an integration function; and
δpeff is the effective deflection angle of ailerons of the aircraft.
2. The method as claimed in claim 1 , wherein in step a), said roll objective is generated by an automatic control device of the aircraft.
3. The method as claimed in claim 1 , wherein in step a), said roll objective is generated by a stick system comprising a roll control stick which is configured to be actuated by a pilot of the aircraft.
4. The method as claimed in claim 1 , wherein said roll objective is expressed as a roll angle.
5. The method as claimed in claim 1 , wherein said roll objective is expressed as a roll rate.
6. The method as claimed in claim 1 , wherein:
the effective value Peff of said roll rate is measured; and
in step c1), said roll acceleration order P1 is calculated with the aid of the following expression:
P 1=ω( PO−Peff )
in which:
PO represents said roll objective; and
ω represents an adjustable angular frequency.
7. The method as claimed in claim 1 , wherein said roll coefficient is determined with aid of a neural net.
8. The method as claimed in claim 1 , wherein said effectiveness coefficient ∂Cl/∂δl is determined with the aid of a neural net.
9. A method of active control of a roll of an aircraft, comprising:
a) generating a roll objective, which is expressed as a roll parameter related to the roll and which is applied to the aircraft;
b) determining effective values of parameters of the aircraft;
c) calculating a deflection order δp on the basis of said roll objective and of said effective values; and
d) applying said deflection order δp exclusively to airfoils of the aircraft, which are efficient on a roll axis, so as to control the roll,
wherein in step c):
a first value is calculated on the basis of said roll objective; and
said deflection order δp is calculated on the basis of the first value and of said effective values which comprise the effective value of the roll rate, by using at least one integration function,
wherein in step c), said deflection order δp is calculated with aid of the following expression:
δ p=Ka∫ (φ com−φeff ) dt+Kbφeff+KcPeff
in which:
Ka, Kb and Kc are predetermined coefficients;
∫ illustrates an integration function;
φeff is the effective value of the lateral attitude of the aircraft;
Peff is the effective value of the roll rate of the aircraft; and
φcom is a controlled value of the lateral attitude, which is determined with the aid of said roll parameter.
10. The method as claimed in claim 9 , wherein said effective value φeff of a lateral attitude is limited by predetermined threshold values.
11. The method as claimed in claim 9 , wherein a direct deflection order is calculated, and is applied at a same time to ailerons and to spoilers of the aircraft.
12. The method as claimed in claim 9 , wherein in step a), said roll objective is generated by an automatic control device of the aircraft.
13. The method as claimed in claim 9 , wherein in step a), said roll objective is generated by a stick system comprising a roll control stick which is configured to be actuated by a pilot of the aircraft.
14. The method as claimed in claim 9 , wherein said roll objective is expressed as a roll angle.
15. The method as claimed in claim 9 , wherein said roll objective is expressed as a roll rate.
16. A device for active control of a roll of an aircraft, said device comprising:
a generating device for generating a roll objective, which is expressed as a roll parameter related to the roll and which is applied to the aircraft;
a measuring device for measuring effective values of parameters of the aircraft;
a calculation device for calculating, on the basis of said roll objective and of said effective values, a deflection order; and
an actuating device for actuating airfoils of the aircraft which are efficient on a roll axis, to which is transmitted said deflection order which is applied exclusively to said airfoils to control the roll of the aircraft,
wherein said calculation device calculates:
on the basis of said roll objective, a first value;
said deflection order on the basis of the first value and of said effective values which comprise the effective value of the roll rate by using at least one integration function;
on the basis of said roll objective, a roll acceleration order; and
said deflection order δp with the aid of the following expressions:
{
δ
p
=
(
P
1
-
F
+
Δ
RMI
)
G
F
=
ρ
V
2
SlCl
2
I
G
=
ρ
V
2
Sl
(
∂
C
l
∂
δ
p
)
2
I
Δ
RMI
=
K
(
-
Peff
+
∫
(
F
+
G
δ
peff
-
Δ
RMI
)
·
ⅆ
t
)
in which:
P1 represents said roll acceleration order;
ρ is the density of the air;
V is the speed of the aircraft;
S is a reference area of the aircraft;
l is a reference length of the aircraft:,
Cl represents a roll coefficient;
I represents the roll inertia of the aircraft;
∂Cl/∂δp represents an effectiveness coefficient;
K represents a predetermined coefficient;
Peff represents the effective value of the roll rate;
∫ illustrates an integration function; and
δpeff is the effective deflection angle of ailerons of the aircraft.
17. An aircraft, comprising a device as defined in claim 16 .
18. A device for active control of a roll of an aircraft, said device comprising:
a generating device for generating a roll objective, which is expressed as a roll ammeter related to the roll and which is applied to the aircraft;
a measuring device for measuring effective values of parameters of the aircraft;
a calculation device for calculating, on the basis of said roll objective and of said effective values, a deflection order; and
an actuating device for actuating airfoils of the aircraft which are efficient on a roll axis, to which is transmitted said deflection order which is applied exclusively to said airfoils to control the roll of the aircraft,
wherein said calculation device calculates:
on the basis of said roll objective, a first value;
said deflection order on the basis of the first value and of said effective values which comprise the effective value of the roll rate by using at least one integration function; and said deflection order δp with the aid of the following expression:
δ p=Ka ∫(φ com−φeff ) dt+Kbφeff+KcPeff
in which:
Ka, Kb and Kc are predetermined coefficients;
∫ illustrates an integration function;
φeff is the effective value of the lateral attitude of the aircraft;
Peff is the effective value of the roll rate of the aircraft; and
φcom is a controlled value of the lateral attitude, which is determined with the aid of said roll parameter.