Apparatus for warning of exceeding speed limit in railway vehicles

Patent metadata

Field	Value
Publication number	US-9718485-B2
Application number	US-201514837918-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Sep 17, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

The present disclosure relates to an apparatus for warning of exceeding speed limit in railway vehicles, wherein a train speed is estimated after a predetermined time, a remaining time is calculated until a train reaches a speed limit based on the estimated speed, and when the calculated time is smaller than a preset reference value, a warning signal is generated. Thus, an adequate warning can be given to cater to a train operation situation because a TTSLC indicator is used that notifies when an emergency braking will be activated by exceeding a set speed limit value after a certain time lapses, resultantly increasing the train operation frequency and the availability of trains.

First claim

What is claimed is:

1. An apparatus for providing a warning of potentially exceeding a speed limit in a railway vehicle, the apparatus comprising: an estimation unit that estimates a future speed of the railway vehicle based on a current speed of the railway vehicle and operational information related to an environment in which the railway vehicle operates; an Automatic Train Protection (ATP) system that automatically applies a braking force to reduce a current speed of the railway vehicle when the current speed exceeds a preset braking speed limit, the automatic braking unit having a corresponding preset ATP warning speed limit at which an automated first warning signal is generated; a determination unit that utilizes the estimated future speed to determine a time period from a current time to a time when the railway vehicle will reach the preset braking speed limit speed; and a warning generation unit that provides a second warning signal when the determined time period is less than a preset reference period, wherein the estimation unit receives the operational information and estimates the future speed based on at least a constant tractive force and a constant braking force applied to the railway vehicle, wherein the operational information comprises at least the tractive force, the braking force, the current speed, track gradient information and track curvature information, and wherein the warning generation unit provides the second warning signal at a speed that is greater than the preset ATP warning speed such that the railway vehicle operates at a speed greater than the preset ATP warning speed without the second warning signal being generated.

2. The apparatus of claim 1 , wherein the estimation unit:
receives the operational information from a propulsion system or a braking system;
generates a dynamics model of the railway vehicle based on a longitudinal dynamics model of the railway vehicle; and
estimates the future speed based on the generated dynamics model.

3. The apparatus of claim 1 , wherein:
the estimation unit estimates the future speed at an nth step subsequent to a current kth step using the following Equation:

v
⁡

(

k
+
n

)

=

v
⁡

(

k
+
n
-
1

)

+

Δ
⁢

⁢
T

m

⁡

[

c
2

⁢

v
⁡

(

k
+
n
-
1

)

-

c
3

⁢

v
⁡

(

k
+
n
-
1

)

2

]

+

Δ
⁢

⁢
T

m

⁡

[

T
e

⁡

(
k
)

-

T
b

⁡

(
k
)

-

mg
⁢

⁢

θ
⁡

(
k
)

-

c
4

r
⁡

(
k
)

]

,

c 2 , c 3 , c 4 are constants;
m is an equivalent mass of the railway vehicle;
g is a gravitational acceleration;
θ is a gradient angle;
r is the radius of curvature;
k and n are steps;
v is a speed of the railway vehicle;
T e is the tractive force;
T b is the braking force; and
ΔT is a sampling period.

4. The apparatus of claim 1 , wherein:
the determination unit calculates TTSLC (Time-To-Speed-Limit-Cr

Assignees

• Lsis Co Ltd

Inventors

• Jung Jongchul
• Cho Yong Gee

Classifications

• B61L15/0072

  On-board train data handling · CPC title

• B61L27/0038

  Operations & Transport · mapped topic

• B61L3/006

  Operations & Transport · mapped topic

• B61L2201/00

  Control methods · CPC title

• B61L25/025

  Absolute localisation, e.g. providing geodetic coordinates · CPC title