Method for managing braking in a degraded adhesion condition for a vehicle system
A system and method for managing braking in a degraded adhesion condition for a vehicle system including at least one vehicle comprising setting a target deceleration value, applying a non-degraded braking force via a braking system of the vehicle system, detecting a presence of a degraded adhesion condition between the vehicle system and a route along which the vehicle system moves. Responsive to the degraded adhesion condition not being detected, maintaining the application of the non-degraded braking force, or responsive to the degraded adhesion condition being detected, applying a degraded braking force, activating recovery means to control deceleration of the vehicle system, determining a compensation deceleration value, and applying at least one of the braking system or recovery means to control the deceleration of the vehicle system.
1. A method comprising:
setting a target deceleration value to be reached by a vehicle system comprising at least one vehicle, the target deceleration value set using one or more processors of a brake management system, the target deceleration value set to allow the vehicle system to reach a zero traveling speed within a target stopping distance and within a first time;
applying a non-degraded braking force using at least one braking system of the vehicle system, a value of the non-degraded braking force calculated by the one or more processors of the brake management system to obtain the target deceleration value;
checking a presence of a degraded adhesion condition between the vehicle system and a route along which the vehicle system moves using the one or more processors of the brake management system; and one or more of:
(a) responsive to the degraded adhesion condition not being detected, maintaining application of the non-degraded braking force with the at least one braking system of the vehicle system, which will allow the vehicle system to reach the target deceleration value within a first time and allow the vehicle system to achieve accordingly a zero traveling speed within the target stopping distance; or
(b) responsive to the degraded adhesion condition being detected:
applying a degraded braking force with the at least one braking system that is lower than the non-degraded braking force and coinciding with an upper limit braking force based on the degraded adhesion condition;
activating a rail vehicle sandbox, a magnetic shoe, a magnetic track brake, or an eddy current brake to control deceleration of the vehicle system using the one or more processors of the brake management system, the rail vehicle sandbox, the magnetic shoe, the magnetic track brake, or the eddy current brake allowing the vehicle system to reach the target deceleration value within a second time that is greater than the first time to allow the vehicle system to reach a zero traveling speed within a degraded stopping distance that is greater than the target stopping distance;
determining a compensation deceleration value as a function of the degraded stopping distance based on one or more difference between the degraded braking force and the non-degraded braking force using the one or more processors of the brake management system, the compensation deceleration value being arranged by the one or more processors of the brake management system to allow the vehicle system to reach a zero traveling speed within the target stopping distance; and
applying at least one of: the at least one braking system or the rail vehicle sandbox, the magnetic shoe, the magnetic track brake, or the eddy current brake to control one or more of the deceleration of the vehicle system or a compensation braking force using the one or more processors of the brake management system, the compensation braking force being greater than the non-degraded braking force and based on the compensation deceleration value, to the compensation braking force allowing the vehicle system to reach the compensation deceleration value and to reach the zero traveling speed within the target stopping distance.
2. The method of claim 1 , wherein the target stopping distance is based on one or more of an initial traveling speed of the vehicle system, an average deceleration value based on an average of one or more deceleration values obtained during application of the non-degraded braking force, up to when the vehicle system reaches the zero traveling speed, and a target braking time obtained through a ratio between an initial traveling speed of the vehicle system and the average deceleration value.
3. The method of claim 2 , wherein the target stopping distance is represented by Dis obb and is calculated based on:
Dis
obb
=
Initial
speed
*
target
braking
time
-
1
2
Average
deceleration
*
target
braking
time
2
.
4. The method of claim 1 , wherein the compensation braking force is lower than a braking limit.
5. The method of claim 1 , further comprising:
providing a signal to an operator of the vehicle system responsive to the compensation braking force exceeding a value of non-degraded force.
6. The method of claim 1 , wherein the degraded stopping distance is determined at certain instants of time based on:
D
i
s
d
e
g
(
t
)
=
∫
0
t
(
∫
0
t
Dec
(
t
)
dt
-
∫
0
t
D
i
s
o
b
b
dt
)
dt
where Dis deg (t) is the degraded stopping distance measured at a time t, Dec(t) is an instantaneous deceleration value measured at the time t and Dis obb is the target deceleration value.
7. The method of claim 1 , wherein the at least one braking system comprises one of an electromechanical brake, an electro-pneumatic brake, an electrodynamic brake, a pneumatic brake, or a hydraulic brake.
8. A brake management system, comprising:
one or more processors configured to set a target deceleration value to be reached by a vehicle system comprising at least one vehicle, the target deceleration value allowing the vehicle system to reach a zero traveling speed within a target stopping distance and within a first time, the one or more processors configured to direct at least one braking system of the vehicle system to apply a non-degraded braking force, a value of the non-degraded braking force calculated to obtain the target deceleration value, the one or more processors configured to check a presence of a degraded adhesion condition between the vehicle system and a route along which the vehicle system moves, wherein:
responsive to the degraded adhesion condition not being detected, the one or more processors are configured to direct the at least one braking system to maintain application of the non-degraded braking force, which will allow the vehicle system to reach the target deceleration value within a first time and allow the vehicle system to achieve accordingly a zero traveling speed within the target stopping distance; or
responsive to the degraded adhesion condition being detected, the one or more processors are configured to direct the at least one braking system to:
apply a degraded braking force with the braking system that is lower than the non-degraded braking force and coinciding with an upper limit braking force based on the degraded adhesion condition;
activate a recovery means arranged to control deceleration of the vehicle system, the recover means allowing the vehicle system to reach the target deceleration value within a second time that is greater than the first time to allow the vehicle system to reach a zero traveling speed within a degraded stopping distance that is greater than the target stopping distance;
determine a compensation deceleration value as a function of the degraded stopping distance based on one or more difference between the degraded braking force and the non-degraded braking force, the compensation deceleration value being arranged to allow the vehicle system to reach a zero traveling speed within the target stopping distance; and
apply at least one of the braking system or the recovery means to control one or more of the deceleration of the vehicle system or a compensation braking force, the compensation braking force being greater than the non-degraded braking force and based on the compensation deceleration value, to the compensation braking force allowing the vehicle system to reach the compensation deceleration value and to reach the zero traveling speed within the target stopping distance.
9. The brake management system of claim 8 , wherein the one or more processors are configured to determine the target stopping distance based on one or more of an initial traveling speed of the vehicle system, an average deceleration value based on an average of one or more deceleration values obtained during application of the non-degraded braking force, up to when the vehicle system reaches the zero traveling speed, and a target braking time obtained through a ratio between an initial traveling speed of the vehicle system and the average deceleration value.
10. The brake management system of claim 9 , wherein the one or more processors are configured to calculate the target stopping distance as Dis obb based on:
Dis
obb
=
Initial
speed
*
target
braking
time
-
1
2
Average
deceleration
*
target
braking
time
2
.
11. The brake management system of claim 8 , wherein the compensation braking force is lower than a braking limit.
12. A method comprising:
determining a target deceleration value to be reached by a vehicle system within a first time period that causes the vehicle system to stop within a target stopping distance within a first time, the target deceleration value determined using one or more processors of a brake management system;
applying a non-degraded braking force using at least one braking system of the vehicle system that obtains the target deceleration value;
determining whether a degraded adhesion condition between the vehicle system and a route along which the vehicle system moves exists using the one or more processors of the brake management system; and
responsive to the degraded adhesion condition being determined:
applying a degraded braking force with the at least one braking system that is lower than the non-degraded braking force;
controlling deceleration of the vehicle system using the at least one braking system to reach the target deceleration value within a longer second time that is longer than the first time to allow the vehicle system to reach a zero traveling speed within a degraded stopping distance that is longer than the target stopping distance;
determining a compensation deceleration value as a function of the degraded stopping distance using the one or more processors of the brake management system and based on one or more differences between the degraded braking force and the non-degraded braking force; and
applying the braking system using the at least one braking system to control one or more of the deceleration of the vehicle system or a compensation braking force, the compensation braking force being greater than the non-degraded braking force and based on the compensation deceleration value.
13. The method of claim 12 , wherein the target stopping distance is based on one or more of an initial traveling speed of the vehicle system, an average deceleration value based on an average of one or more deceleration values obtained during which the non-degraded braking force is applied, and a target braking time obtained through a ratio between an initial traveling speed of the vehicle system and the average deceleration value.
14. The method of claim 12 , wherein the compensation braking force is smaller than a braking limit.
15. The method of claim 12 , further comprising:
providing a signal to an operator of the vehicle system responsive to the compensation braking force exceeding a value of non-degraded force.
16. The method of claim 12 , wherein the degraded stopping distance is determined based on an instantaneous deceleration value and the target deceleration value.