# US 9,004,412 B2 · Rail collision threat detection system

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- Number: US 9,004,412 B2
- Document ID: US9004412B2
- Status: Granted
- Kind: B2
- Application number: 13/547,613
- Filed: 2012-07-12
- Published: 2014-01-16
- Granted: 2015-04-14
- Earliest claimed: 2012-07-12
- Assignees: Electro-Motive Diesel, Inc.
- Applicants: Dale Alexander Brown
- Inventors: Dale Alexander Brown
- Web page: https://patentgrep.com/patent/US9004412B2

## CPC

- B61L 15/0027: {Radio-based, e.g. using GSM-R}
- B61L 15/0054: {Train integrity supervision, e.g. end-of-train [EOT] devices}
- B61L 23/34: for indicating the distance between vehicles or trains by the transmission of signals therebetween
- B61L: GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC (brakes or auxiliary equipment B61H, B61K; point or crossing construction E01B)

## Abstract

A detection system may include a transmitter associated with a first train configured to emit an end-of-train signal. The detection system may include a receiver associated with the transmitter and configured to receive the end-of-train signal from the transmitter. The receiver may also be configured to receive at least one remote signal from a second train and determine whether the second train is a collision threat based on the remote signal from the second train.

## Claims

### Claim 1

A detection system comprising:
a transmitter associated with a first train and configured to emit an end-of-train signal; and
a receiver associated with the transmitter and the first train and configured to:
receive the end-of-train signal from the transmitter;
receive at least one remote signal from a second train;
detect a signal strength of the remote signal;
determine a relative distance of the second train from the first train based on the signal strength of the remote signal; and
determine whether the second train is a collision threat to the first train based on the remote signal from the second train.

### Claim 2 (depends on 1)

The detection system of claim 1, wherein a communication frequency at which the receiver is configured to receive signals is the same frequency used by both the first and second train for end-of-train communications.

### Claim 3 (depends on 1)

The detection system of claim 1, wherein the remote signal comprises an end-of-train signal from a second transmitter associated with the second train.

### Claim 4 (depends on 3)

The detection system of claim 3, wherein the remote signal further includes a track identifier, and the receiver is configured to determine whether the second train is a collision threat based on the track identifier and a track on which the first train is located.

### Claim 5 (depends on 1)

The detection system of claim 1, wherein the receiver is configured to:
determine whether the second train is within a warning range of the receiver; and
in the event the second train is within the warning range, identify the collision threat based on the relative distance and the speed of the second train.

### Claim 6 (depends on 5)

The detection system of claim 5, further including:
a warning system configured to notify at least one of a dispatch and a train operator of the collision threat; and
a braking controller configured to initiate a braking force of the first train.

### Claim 7

A method for detecting a collision threat between a first train and a second train comprising:
receiving on the first train a signal from the second train;
detecting a signal strength of the signal;
determining a relative distance between the first train and the second train based on the signal strength; and
identifying whether the second train is a collision threat to the first train based on the relative distance.

### Claim 8 (depends on 7)

The method of claim 7, further including:
notifying at least one of a dispatch and an operator of the first train of the collision threat; and
sending a command to initiate a braking force of the first train.

### Claim 9 (depends on 8)

The method of claim 8, further including identifying an occupied track, wherein the signal is indicative of a track on which the first train is travelling and identifying whether the second train is a collision threat is further based on whether the track on which the second train is travelling is the same as the occupied track.

### Claim 10 (depends on 9)

The method of claim 9, further including:
identifying a home train; and
determining whether the signal is received from the home train, wherein the signal is indicative of a train identifier.

### Claim 11 (depends on 9)

The method of claim 9, further including:
determining the second train is approaching on a second track based on the relative distance;
determine a time at which the home train and the train will pass based on the relative distance and the relative speed; and
notifying the dispatch that the second train and the home train will pass one another.

### Claim 12 (depends on 7)

The method of claim 7, further including:
receiving a second signal from the second train;
detecting a second signal strength of the second signal; and
determining a relative speed of the second train based on a time between receiving the first and second signals and the difference between the first and second signal strength, wherein identifying whether the second train is a collision threat is further based on the relative speed of the second train.

### Claim 13 (depends on 12)

The method of claim 12, further including determining a travel direction of the second train based on the relative speed of the second train and the second signal strength, wherein identifying whether the second train is a collision threat is further based on the travel direction of the second train.

### Claim 14

A first train comprising:
a locomotive;
a transmitter associated with at least one of the locomotive and a trailing railcar and configured to emit an end-of-train signal; and
a receiver associated with the locomotive and configured to:
receive the end-of-train signal from the transmitter;
receive a remote signal from a second train;
detect a signal strength of the remote signal;
determine a relative distance of the second train from the first train based on the signal strength of the remote signal; and
determine whether the second train poses a collision threat to the first train based on the remote signal.

### Claim 15 (depends on 14)

The first train of claim 14, wherein a communication frequency at which the receiver is configured to receive signals is the same frequency used by both the first and second train for end-of-train communications.

### Claim 16 (depends on 14)

The first train of claim 14, wherein the remote signal comprises an end-of-train signal from a second transmitter associated with the second train.

### Claim 17 (depends on 16)

The first train of claim 16, wherein the second signal further includes a track identifier, and the receiver is configured to determine whether the second train is a collision threat based on the track identifier and a track on which the second train is travelling.

### Claim 18 (depends on 14)

The train of claim 14, wherein the receiver is configured to:
receive a second remote signal from the second train;
detecting a second signal strength of the second remote signal; and
determine a travel direction of the second train based on the relative speed of the second train and the second signal strength.