Brake load balance and runway centering techniques
A method for controlling brakes may comprise receiving, by a controller, a yaw rate from an inertial sensor, calculating, by the controller, a force correction, calculating, by the controller, a pressure correction, and adjusting, by the controller, a pressure command for a brake control device.
1. A brake control system, comprising:
an inertial sensor coupled to an aircraft configured to measure a yaw acceleration of the aircraft;
a brake control unit (BCU) configured to receive the yaw acceleration from the inertial sensor, and control a brake control device based on the yaw acceleration,
wherein the BCU is configured to calculate a brake pressure correction using the yaw acceleration and equation
Δ
P
_
j
=
±
Δ
F
d
_
x
*
R
rolling
x
-
I
wh
_
x
*
ω
.
m
a
x
/
m
i
n
A
·
k
·
n
·
R
b
·
μ
cc
wherein ΔP_j is a brake pressure correction, ΔF d _ x is a brake force correction, R rolling x is a rolling radius of a wheel, I wh _ x is a rotational moment of inertia of the wheel, {dot over (ω)} max/min is one of the maximum allowable deceleration of the wheel and a minimum allowable deceleration of the wheel, A is a piston area, k is a number of friction disks, n is a number of brake stacks, R b is a brake force torque arm, and μ cc is a friction coefficient of the friction disks.
2. The brake control system of claim 1 , wherein the BCU is configured to calculate a brake force correction for the brake control device based upon the yaw acceleration.
3. The brake control system of claim 2 , wherein the BCU is configured to calculate the brake force correction based upon the yaw acceleration and configured to calculate a brake pressure correction for the brake control device based upon the brake force correction.
4. The brake control system of claim 1 , further comprising a wheel speed sensor configured to measure a rotational speed of a wheel of the aircraft.
5. The brake control system of claim 4 , wherein the BCU is configured to calculate a wheel deceleration based upon the rotational speed.
6. The brake control system of claim 5 , wherein the BCU is configured to calculate a brake pressure correction based upon the wheel deceleration.
7. A method for controlling brakes, comprising:
receiving, by a brake control unit (BCU), a yaw acceleration from an inertial sensor; and
adjusting, by the BCU, a brake command for a brake control device based upon the yaw acceleration; and
calculating, by the BCU, a brake force correction based upon the yaw acceleration,
wherein the yaw acceleration is a yaw acceleration of an aircraft, and
the brake force correction is calculated using at least one of equation
Δ
F
d
_
x
=
I
L
*
β
¨
1
L
LG
and equation
Δ
F
d
_
x
=
I
L
*
β
¨
1
L
LG
*
1
2
,
where {umlaut over (β)} l is the yaw acceleration, I L is a moment of inertia of an aircraft, L LG is a distance between a landing gear and an aircraft center of gravity, and ΔF d _ x is the brake force correction.
8. The method of claim 7 , wherein the brake force correction is calculated using at least one of equation
Δ
F
d_x
=
I
L
*
β
¨
1
L
LG
and equation
Δ
F
d_x
=
I
L
*
β
¨
1
L
LG
*
1
2
,
where {umlaut over (β)} l is the yaw acceleration, I L is a moment of inertia of an aircraft, L LG is a distance between a landing gear and an aircraft center of gravity, and ΔF d _ x is the brake force correction.
9. The method of claim 7 , further comprising calculating, by the BCU, a brake pressure correction based upon the brake force correction, wherein the brake pressure correction is calculated using the brake force correction.
10. The method of claim 9 , wherein the brake pressure correction is calculated using equation
ΔP
_j
=
±
Δ
F
d_x
*
R
rolling
x
-
I
wh_x
*
ω
·
ma
x
/
m
i
n
A
·
k
·
n
·
R
b
·
μ
cc
,
wherein ΔP_j is a brake pressure correction, ΔF d _ x is a brake force correction, R rolling x is a rolling radius of a wheel, I wh _ x is a rotational moment of inertia of the wheel, {dot over (ω)} max/min is one of a maximum allowable deceleration of the wheel and a minimum allowable deceleration of the wheel, A is a piston area, k is a number of friction disks, n is a number of brake stacks, R b is a brake force torque arm, and μ cc is a friction coefficient of the friction disks.
11. The method of claim 7 , further comprising sending, by the BCU, the adjusted brake command to the brake control device.
12. A method for controlling brakes, comprising:
receiving, by a brake control unit (BCU), a yaw acceleration from an inertial sensor; and
adjusting, by the BCU, a brake command for a brake control device based upon the yaw acceleration; and
calculating, by the BCU, a brake force correction based upon the yaw acceleration,
wherein the yaw acceleration is a yaw acceleration of an aircraft, and
the brake force correction is calculated using at least one of equation
Δ
F
d_x
=
I
L
*
β
¨
1
L
LG
and equation
Δ
F
d_x
=
-
I
L
*
β
¨
1
L
LG
*
1
2
,
where {umlaut over (β)} l is the yaw acceleration, I L is a moment of inertia of an aircraft, L LG is a distance between a landing gear and an aircraft center of gravity, and ΔF d _ x is the brake force correction.
13. The method of claim 12 , further comprising calculating, by the BCU, a brake pressure correction based upon the brake force correction, wherein the brake pressure correction is calculated using the brake force correction.
14. The method of claim 13 , wherein the brake pressure correction is calculated using equation
ΔP
_j
=
±
Δ
F
d_x
*
R
rolling
x
-
I
wh_x
*
ω
·
ma
x
/
m
i
n
A
·
k
·
n
·
R
b
·
μ
cc
,
wherein ΔP_j is a brake pressure correction, ΔF d _ x is a brake force correction, R rolling x is a rolling radius of a wheel, I wh _ x is a rotational moment of inertia of the wheel, {dot over (ω)} max/min is one of a maximum allowable deceleration of the wheel and a minimum allowable deceleration of the wheel, A is a piston area, k is a number of friction disks, n is a number of brake stacks, R b is a brake force torque arm, and μ cc is a friction coefficient of the friction disks.