Vehicle detection system

• US 8,157,219 B2
• Filed: 01/15/2008
• Issued: 04/17/2012
• Est. Priority Date: 01/15/2007
• Status: Expired due to Fees

• Current Assignee: Central Signal, LLC
• Original Assignee: Central Signal, LLC
• Inventors: Ashraf, Ahtasham, Baldwin, David
• Primary Examiner(s): Morano, S. Joseph
• Assistant Examiner(s): Smith, Jason C
• Application Number:
  US12/014,630
• Publication Number:
  US 20080169385A1
• Time in Patent Office: 1,554 Days
• Field of Search: 246/111, 246/130, 246/122.R, 246/202, 246/208, 246/249, 246/247, 246/360, 246/473.1, 246/293, 246/292, 246/220, 246/125, 246/126
• US Class Current: 246/130
• CPC Class Codes: B61L 29/22 electrically
• CPC Class Codes: B61L 29/28 electrically operated
• CPC Class Codes: B61L 29/282 magnetic or inductive control by the vehicle

Abstract

An vehicle detection system is provided for tracking, detecting, and monitoring vehicles. The system and methods of the present invention are suitable for on track and roadway vehicles. In particular the present invention provides an improved and cost effective system and methods for tracking, detecting and monitoring locomotives and on track vehicles.

Claims

1. A railroad train detection system comprising:

a first multidimensional anisotropic magnetoresistive (AMR) sensor fixed in proximity to a railroad track;

a second multidimensional AMR sensor fixed in proximity to the railroad track and spaced apart from the first AMR sensor;

wherein each AMR sensor is configured to generate multidimensional analog waveform data representative of changes in a generally constant magnetic field environment due to the presence of a railroad train passing on the railroad track;

a signal processor configured to generate multidimensional digital waveform data based on multidimensional analog waveform data generated by the first and second AMR sensors; and

a waveform data transmitter configured to transmit multidimensional digital waveform data from the signal processor to a system processing apparatus, wherein the system processing apparatus is configured to control an active warning device at a railroad track crossing using the transmitted digital waveform data;

wherein the signal processor comprises;

a filter and amplifier configured to convert multidimensional analog waveform data to processed multidimensional analog waveform data;

an analog-to-digital converter configured to convert processed multidimensional analog waveform data to multidimensional digital waveform data; and

an encoder configured to encode multidimensional digital waveform data to generate encoded multidimensional digital waveform data;

further wherein waveform data transmitter transmission of multidimensional digital waveform data comprises transmission of encoded multidimensional digital waveform data; and

further wherein the waveform data transmitter is further configured to transmit using spread spectrum radio transmission.

2. The railroad train detection system of claim 1 wherein the signal processor comprises a bias compensator configured to compensate for changes in the first and second AMR sensors due to at least one of the following:

environmental variations;

flux density variations;

humidity variations;

temperature variations;

component variations;

supply voltage variations.

3. The railroad train detection system of claim 1 further comprising a third AMR sensor and a fourth AMR sensor, the first, second, third and fourth AMR sensors defining a detection zone on the railroad track and further defining a crossing zone within the detection zone, wherein the crossing zone comprises the railroad track crossing.

4. The railroad train detection system of claim 1 wherein the system processing apparatus comprises a failsafe processor apparatus configured to cause operation of the active warning device in a safest condition should any element of the system processing apparatus fail, wherein the failsafe processor apparatus is a closed circuit design.

5. The railroad train detection system of claim 1 wherein multidimensional analog waveform data comprises output along three dimensions of space that correspond to the amount and rate of change of magnetic field monitored by each AMR sensor.

6. The railroad train detection system of claim 1 wherein the system processing apparatus activates the active warning device by removing a normally high output signal at a control interface between the system processing apparatus and the active warning device.

7. A railroad train detection system comprising:

a first multidimensional anisotropic magnetoresistive (AMR) sensor fixed in proximity to a railroad track;

a second multidimensional AMR sensor fixed in proximity to the railroad track and spaced apart from the first AMR sensor;

wherein each AMR sensor is configured to generate multidimensional analog waveform data representative of changes in a generally constant magnetic field environment due to the resence of a railroad train a passing on the railroad track;

a signal processor configured to generate multidimensional digital waveform data based on multidimensional analog waveform data generated by the first and second AMR sensors; and

a waveform data transmitter configured to transmit multidimensional digital waveform data from the signal processor to a system processing apparatus, wherein the system processing apparatus is configured to control an active warning device at a railroad track crossing using the transmitted digital waveform data;

wherein the system processing apparatus comprises at least one of the following;

a vital processing module comprising a plurality of microprocessors coupled to provide vital processing of active warning device control data;

a communications module configured to provide communications between the system processing apparatus and the first and second AMR sensors via the waveform data transmitter, and between the system processing apparatus and the active warning device;

a vital I/O module configured to provide vital I/O control of at least one of the following;

one or more railroad signal relays;

one or more control devices;

a diagnostic testing and logging module configured to provide user access to the system processing apparatus to permit one or more of the following;

entry of site specific information, selection or entry of user variable values, performing set-up or other processes, diagnostic testing and to review, download or upload data log files;

a user interface module;

a remote operations module configured to provide remote communications with the railroad train detection system via cellular or satellite communication to perform at least one of the following;

remote status checking;

alarm notification;

configuration control;

data transfer.

8. The railroad train detection system of claim 7 wherein the signal processor comprises a bias compensator configured to compensate for changes in the first and second AMR sensors due to at least one of the following:

environmental variations;

flux density variations;

humidity variations;

temperature variations;

component variations;

supply voltage variations.

9. The railroad train detection system of claim 7 wherein

the signal processor comprises:

a filter and amplifier configured to convert multidimensional analog waveform data to processed multidimensional analog waveform data;

an analog-to-digital converter configured to convert processed multidimensional analog waveform data to multidimensional digital waveform data; and

an encoder configured to encode multidimensional digital waveform data to generate encoded multidimensional digital waveform data;

further wherein waveform data transmitter transmission of multidimensional digital waveform data comprises transmission of encoded multidimensional digital waveform data; and

further wherein the waveform data transmitter is further configured to transmit using spread spectrum radio transmission.

10. The railroad train detection system of claim 9 wherein the signal processor further comprises a bias compensator configured to compensate for changes in the first and second AMR sensors due to at least one of the following:

environmental variations;

flux density variations;

humidity variations;

temperature variations;

component variations;

supply voltage variations.

11. The railroad train detection system of claim 10 wherein the system processing apparatus comprises a failsafe processor apparatus configured to cause operation of the active warning device in a safest condition should any element of the system processing apparatus fail, wherein the failsafe processor apparatus is a closed circuit design.

12. The railroad train detection system of claim 11 wherein multidimensional analog waveform data comprises output along three dimensions of space that correspond to the amount and rate of change of magnetic field monitored by each AMR sensor.

13. The railroad train detection system of claim 12 wherein the system processing apparatus activates the active warning device by removing a normally high output signal at a control interface between the system processing apparatus and the active warning device.

14. The railroad train detection system of claim 13 wherein the system processing apparatus comprises a plurality of redundant microprocessors, wherein each microprocessor monitors heartbeats from any other microprocessor in the system processing apparatus and further wherein the active warning device is activated if any heartbeats do not agree.

15. The railroad train detection system of claim 14 wherein encoded multidimensional digital waveform data received by the system processing apparatus is used to determine at least one of the following:

the presence of a train that is stationary on the railroad track;

train speed;

train direction of movement;

train length;

train size;

train identification;

type of rail car in a given train;

train position on the railroad track;

stopping of a train on the railroad track;

reversal of direction of a train on the railroad track.

16. A railroad train detection system comprising:

a plurality of multidimensional anisotropic magnetoresistive (AMR) sensors fixed in proximity to a railroad track, wherein the plurality of multi-dimensional AMR sensors define a train detection zone on the railroad track;

wherein each AMR sensor is configured to generate multidimensional analog waveform data representative of changes in the Earth'"'"'s generally constant magnetic field due to the presence of one or more nearby railroad train cars in the detection zone;

a signal processor configured to generate multidimensional digital waveform data based on multidimensional analog waveform data generated by the plurality of AMR sensors;

a waveform data transmitter configured to transmit multidimensional digital waveform data from the signal processor to a system processing apparatus; and

the system processing apparatus configured to receive, process and compare waveform data from the plurality of AMR sensors, wherein the system processing apparatus is further configured to determine at least one of the following;

speed of a train in the detection zone;

direction of movement of a train in the detection zone;

length of a train in the detection zone;

size of a train in the detection zone;

stopping and reversing direction by a train in the detection zone;

stopping of a train in the detection zone;

changes in speed of a train in the detection zone;

decoupling of one or more train cars by a train in the detection zone;

multidimensional representation of magnetic fields in the detection zone.

17. The railroad train detection system of claim 16 wherein the plurality of AMR sensors are spaced apart by a spacing of at least 10 meters.

18. The railroad train detection system of claim 17 wherein the waveform data transmitter is a wireless transmitter using radio signals.

19. The railroad train detection system of claim 17 further comprising one or more bias compensators configured to maintain approximately optimum bias for each of the plurality of AMR sensors.

20. The railroad train detection system of claim 16 further comprising a vital processing module, the vital processing module comprising two redundant microprocessors and redundant relay driver circuits, wherein the redundant microprocessors are configured to perform health checks of each other using heartbeat signals.

21. A railroad train detection system comprising:

a plurality of sensor devices fixed in proximity to a railroad track, wherein each sensor device comprises one or more multidimensional anisotropic magnetoresistive (AMR) sensors, further wherein the plurality of sensor devices define a train detection zone on the railroad track;

wherein each AMR sensor is configured to generate multidimensional analog waveform data representative of changes in the Earth'"'"'s generally constant magnetic field due to the presence of one or more nearby railroad train cars in the detection zone;

at least one signal processor configured to generate multidimensional digital waveform data based on multidimensional analog waveform data generated by one or more of the AMR sensors;

a waveform data transmitter configured to transmit multidimensional digital waveform data from the signal processor to a system processing apparatus; and

the system processing apparatus configured to receive, process and compare waveform data from the plurality of AMR sensors, wherein the system processing apparatus is further configured to determine at least one of the following;

speed of a train in the detection zone;

direction of movement of a train in the detection zone;

length of a train in the detection zone;

size of a train in the detection zone;

stopping and reversing direction by a train in the detection zone;

stopping of a train in the detection zone;

changes in speed of a train in the detection zone;

decoupling of one or more train cars by a train in the detection zone;

multidimensional representation of magnetic fields in the detection zone.