WO2001091083A1

WO2001091083A1 - Self-testing train detection system

Info

Publication number: WO2001091083A1
Application number: PCT/US2001/016584
Authority: WO
Inventors: Joseph R. Pace; Joseph A. Pace
Original assignee: Eva Signal Corporation
Priority date: 2000-05-25
Filing date: 2001-05-23
Publication date: 2001-11-29
Also published as: AU2001274897A1

Abstract

The present invention is directed to a train detection system (10) for detecting the velocity, presence, and direction of a railroad car (52) which may be utilized in existing railroad crossing installations. The train detection system (10) is suitable for self-testing of its components and if an anomaly has been detected, the train detection system (10) is capable of placing the system in a fail-safe state. The train detection system (10) of the present invention is also capable of constant communication between the sensor (100) of the system and the implementing device (105) of the train detection system (10) via a wireless link (210, 212).

Description

SELF-TESTING TRAIN DETECTION SYSTEM CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of United States Application Serial No.

09/448,953 filed November 24, 1999, which is a continuation of United States Application Serial No. 09/344,477 filed June 25, 1999, which is a continuation-in-part of United States Application

Serial No. 09/056,201 filed April 6, 1998, now U. S. Patent No. 5,954,299 issued September 21,

1999; which is a divisional of United States Application Serial No. 08/710,147 filed September 16,

1996, nowU.S. Patent No.5,735,492, issued April 7, 1998, which is a continuation-in-part of United

States Application Serial No. 08/601,902 filed February 15, 1996. Said Application Serial No. 08/601,902 claimed the benefit under 35 U.S.C. § 119 of United States Provisional Application

Serial No. 60/009,857 filed January 12, 1996.

The present application is also a continuation-in-part of U.S. Application Serial No 09/084,

863 filed May 26, 1998, which is a continuation-in-part of U.S. Application Serial No. 08/601,902 filed February 15, 1996. SaidU.S. Application Serial No. 08/601,902 claims the benefit under 35 U.S.C. § 119 of U.S. Provisional Application No. 60/009,857.

The following related commonly owned U.S. Patents and Applications are incorporated herein by reference in their entirety:

Applicant(s) Serial No. Filing Date Patent No. Issue Date P Paaccee,, JJ.. 0 099//444488,,995533 November 24, 1999

Pace, J. 09/344,477 June 25, 1999

Pace, J. 09/084,863 May 26, 1998

Pace, J. 08/601,902 February 15, 1996

Pace, J. 08/710,147 September 16, 1996 5,735,492 April 7, 1998 P Paaccee,, JJ.. 0 099//005566,,220011 April 6, 1998 5,954,299 September 21, 1999

Pace, J. 60/009,857 January 12, 1996 FIELD OF THE INVENTION The present invention relates generally to traffic warning systems and more particularly to an improved train detection system for alerting motorists approaching a railroad grade crossing to the presence of an oncoming railroad train. BACKGROUND OF THE INVENTION

Known to the art are active railroad crossing warning systems utilizing the railroad tracks themselves to detect an approaching train and activate a warning signal apparatus such as warning lights and bells. These systems known to the art warn motorists when a train is detected at a predetermined distance from the crossing. However, present active warning systems do not take into account the velocity, size, or location of the train and thus make no allowance for the time it will take the train to reach the crossing. For example, a fast moving train may reach the crossing in only a few seconds after it is detected, while a slow moving train may fail to reach the crossing until several minutes have passed. Motorists may become impatient waiting for slow moving trains to reach the crossing. Consequently, some motorists may begin to ignore the warnings and attempt to cross the tracks possibly causing an accident should a fast moving train be encountered.

Further, installation of current active detection systems may require the installation and resetting of great lengths of track. Further, current detection systems may be susceptible to rail corrosion and degradation over time causing the detection system to malfunction. Additionally, these systems may require the installation of expensive high voltage transformers, relays, and batteries for backup systems. Unfortunately, many rural crossings are not conducive to the installation of active warning systems that require AC electrical power and extensive grade preparation. Consequently, these crossings usually remain inadequately protected. Another disadvantage of railroad warning systems known to the art is that they do not provide fail-safe conditions. For example, some crossings may not provide adequate protection if there is a loss of electrical power or if a component of the detection system has failed. Under such conditions, a railroad warning system may be non-functional without being noticed by railroad personnel and motorists. In order to provide adequate protection to motorists when they encounter a railroad crossing, an improved train detection system is necessary. The impact of high speed rail corridors being proposed across the United States will only exacerbate this need.

SUMMARY OF THE INVENTION

In accordance with this need, the present invention provides a railroad detection system for alerting a motorist approaching a railroad crossing to the presence of an oncoming train. As used herein, "motorist" is intended to refer not only to operators and passengers of motor vehicles, but also to pedestrians, cyclists, bystanders, and the like. Sensors adjacent to the railroad track may be placed at predetermined distances firom the railroad crossing to sense the presence, direction, and velocity of an approaching train. At a predetermined time before the train reaches the crossing, the implementation subsystem may activate a warning system to alert motorists to the presence of the oncoming train. The motorists may then take cautionary or evasive action.

The sensors of the present invention also permit self-testing thus providing a fail-safe condition. The implementation subsystem is in constant communication with the sensors via a hardware or alternatively a wireless connection. Thus, if the sensors or the implementation subsystem should notice an anomaly or are not working properly, the railroad detection system may be placed in a fail-safe condition. Upon entering the fail-safe condition, the warning system located at the railroad crossing may be initiated by the implementation system alerting motorists and railroad personnel that the railroad detection system is non-functional.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and together with the general description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The numerous obj ects and advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:

FIG. 1 is a block diagram of the adaptable and universal nature of the subsystems of the train detection system of the present invention;

FIG. 2 is a highly diagrammatic representation of the primary components of a presently preferred exemplary embodiment of the present invention wherein components of the sensor and implementation subsystem are illustrated; FIG. 3 depicts an exemplary embodiment of a sensor of the present invention;

FIGS .4A and 4B depicts an exemplary embodiment of the magnetic field variation produced by a magneto-resistive chip of the present invention when a train passes near a chip and a digital signal that may be produced utilizing threshold values;

FIG. 5 is a pictorial view of atypical single track grade crossing displaying the location and cross-sectional view of a vault of the present invention;

FIG. 6 is a top plan view of an area surrounding a typical grade crossing depicting the placement of the train detection system's components along the track;

FIG. 7A is an elevational view of the embodiment of the invention shown in FIG. 6 illustrating the operation thereof before an oncoming railroad train reaches the crossing; FIG. 7B is an elevational view of the embodiment of the invention shown in FIG. 6 illustrating the operation thereof after passage of the train; and

FIG. 8 is a flow diagram illustrating an exemplary process of the train detection system of the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT Reference will now be made to a presently preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings.

FIG. 1 depicts the universal and distinct subsystems of an exemplary train detection system 10 of the present invention. In an exemplary embodiment of the present invention, the train detection system 10 comprises a sensor 100 and an implementation subsystem 105. The train detection system 10 may be connected with a warning system 120 in order to adequately alert motorists approaching a railroad crossing to the presence of an oncoming train. Since not all railroad crossings require complete detection and warning systems, the train detection system 10 of the present invention may also be installed with current installations in such a way that the sensor 100 or the implementation subsystem 105 may be installed independently to upgrade current installations. The train detection system 10 of the present invention preferably comprises of subsystems and components that operate separately of the railroad's track, equipment, or systems yet still provide means for detecting an oncoming railroad train.

Referring to FIG. 2, a detailed view of an exemplary embodiment of the train detection system 10 of the present invention displaying the components that comprise the detection system 10 is shown. In a preferred embodiment, the sensors may be capable of operation in different temperature extremes ensuring reliability of the detection system of the present invention. The sensor 100 includes at least two solid state magneto-resistive chips 40 and a processing chip 206.

The magneto-resistive chips 40 may be suitable for detecting a ferromagnetic material object such as a train. In a preferred embodiment, the magneto-resistive chips may be manufactured by the HONEYWELL® Corporation, one example of the magneto-resistive chip 40 being part number 1021S-2. The implementation subsystem 105 may comprise a programmable processor 224 and a rechargeable battery 226. The sensor 100 and the implementation subsystem 105 may be interconnected through a serial line or alternatively through a wireless connection. Utilizing a wireless connection, a first transceiver 210 and a second transceiver 212 may be connected to the processing chip 206 and the programmable processor 206 respectively.

Another advantage of an exemplary embodiment of a detection system 10 of the present invention is that the components of the sensor 100 may be placed within a single enclosure.

Referring now to FIG. 3, an exemplary embodiment of a sensor 100 of the present invention is shown. The magneto-resistive chips 40 and the processing chip 206 may be placed on a circuit board 208 or other similar object for mounting chips. The magneto-resistive chips 40, processing chip 206, and the circuit board 208 may be placed within an enclosure 202 suitable for protecting the components of the sensor 100 from elements and temperature changes when placed underground.

In a preferred embodiment, poly vinyl chloride pipe or other suitable material and the like may serve as the enclosure 202. Turning now to the way in which the sensor 100 of the present invention works, an exemplary embodiment of the sensor 100 as depicted in FIG. 3 may be placed just below ground up to seven feet away from the railroad track. This may be beneficial as maintenance performed on the railroad track may not damage the detection system of the present invention while working on or near the railroad track. When a ferromagnetic material object passes over the sensor 100, it will pass over, adjacent, near, or proximate to the first magneto-resistive chip 40a and then will pass over, adj acent, near, or proximate to the second magneto-resistive chip 40b . When the ferromagnetic material object passes over the magneto-resistive chips 40, each magneto-resistive chip 40 may produce a signal which is received by the processing chip 206. Referring now to FIG. 4A, an exemplary embodiment 400 representing the magnetic field variation of a train measured by the magneto-resistive chips 405a and 405b of the present invention. Signals 410, 420 may be produced by the magneto-resistive chips 405a, 405b respectively when a ferromagnetic material object, a train 430 for example, passes the magneto-resistive chips 405a, 405b. Referring to FIG. 4B, in an exemplary embodiment 450 digital signals 460, 470 may be created from the signals 410, 420 produced when a ferromagnetic material object passes a magneto- resistive chip 405a, 405b by utilizing threshold levels to pick out peaks and valleys. When viewing the digital signal 460 created from the magneto-resistive chip 405a, a timer is started and a direction is determined upon the falling edge of the magneto-resistive chip 405a output. The rising edge of the magneto-resistive chip 405b stops the timer which calculates a change in time whereby the velocity of the train may be calculated by dividing the distance between the magneto-resistive chips divided by the change in time. The magneto-resistive chips may be placed about two to four feet apart within the enclosure protecting the chips, preferably the magneto-resistive chips may be placed about thirty-three inches apart. This may provide enough space in order for a processing chip of the sensor to process the signals produced by each magneto-resistive chip 405a, 405b. Another advantage of the sensor of the present invention is that it will be a rare occurrence that an object would come to a stop between the magneto-resistive chips of the sensor. If the distance between chips is large, then its possible an object could pass the first magneto-resistive chip and stop before reaching the second magneto-resistive chip. This may result in an anomaly and may cause the detection system to enter a fail-safe state. By decreasing the distance between the magneto-resistive chips, the chance that an object may stop between that area is less likely. FIG. 5 depicts atypical railroad crossing 56. In apreferred embodiment, the implementation subsystem 105 may be placed within a waterproof underground vault 34 for security and physical protection. The vault 34 may include a steel access door 36 secured by a locking device 38 such as a hasp to receive a padlock or the like. The buried vault 34 may provide physical security for the implementation subsystem 105 and protect the implementation subsystem's components from the extreme temperature changes that could be experienced. Preferably, the vault 34 may be grounded to provide electrostatic shielding to the electronic components contained therein.

The detection system 10 of the present invention is preferably powered by one or more rechargeable batteries 226 as shown in FIG. 2. Referring once again to FIG. 5, the one or more batteries 226 may be placed in the vault 34 with the programmable processor 224. Recharging of the batteries may be accomplished by means of a solar panel array 45 mounted on a pole, or post 42 near the railroad crossing 56. Use of solar panels 45 may be desirable when the system 10 is to be deployed at crossings located in rural areas where a source of electrical power is not readily available. The solar panel 45 may have a transparent covering comprising ^lA inch thick LEXAN® bullet resistant translucent material or the like to prevent damage due to the environment or vandalism.

FIG. 6 illustrates operation of the detection system 10 to detect an approaching train 52 moving along a railroad track 54. As the train travels towards a railroad crossing 56, it will pass over the sensors 100 as shown in an exemplary embodiment in FIG. 3. _.The sensors 100 may be buried in the right-of-way along the railroad track 54 to protect the sensors 100 from elements and vandalism. The sensors 100 may be connected to the implementation subsystem 105 through a shielded, rodent proof cable 58, or alternatively via a wireless connection. In a hardwire embodiment, the cable 58 may be a foam/skin insulated filled cable meeting REA Specification PE- Alternatively, in another exemplary embodiment the sensor and the implementation subsystem of the present invention may be connected via a wireless connection. Information may be transported from the sensors 100 to the implementation subsystem 105 through signal transmission means. For example, the sensor 100 may be connected with a transceiver suitable for delivering and receiving information to and from the programmable processor of the implementation subsystem. Further, the programmable processor of the implementation subsystem may also be connected with a transceiver suitable for delivering and receiving information. Antennas may be connected with each transceiver in order to aid reception and transmission and increase signal gain of the radio communications link between the sensor and the implementation subsystem. As such, the sensor and the implementation subsystem may be in constant communication with each other, and if the connection malfunctions, the system may be preferably placed into a fail-safe state.

The wireless connection preferably utilizes several bands of spread spectrum channels that does not require a Federal Communications Commission license to operate. Preferably, constant analysis of the bands may be performed in order to ensure best reception. The wireless connection preferably is a dual-tone multiple frequency encoded, spread spectrum modulated transmission to avoid unintended jamming or interference from other frequency resources operating in the vicinity thereby preventing loss of communication or false alarms. Further, in another embodiment the wireless connection may utilize encryption to provide secure transfer of information between the sensor and the implementation subsystem. Also, in yet another embodiment a mobile receiver capable of receiving wireless communication may be utilized, for example, within the train to alert an engineer that the train has been detected by the train detection system.

FIGS. 7A and 7B illustrate operation of the system 10 to sense an approaching train 52 and activate the warning system 120. The train detection system 10 preferably comprises a primary sensor 100a and a secondary or backup sensor 100b. In an exemplary embodiment, the primary sensor 100a comprises at least two solid state magneto-resistive chips positioned on either side of the grade crossing 56 along the track 54 at a predetermined distance from each other. The sensor 100a is preferably located at a sufficient distance from the grade crossing 56 to permit the system 10 to activate the warning signal devices 120 at a predetermined interval of time before the arrival of the train 52 regardless of the train's speed.

A secondary or backup sensor 100b may also be provided should the primary sensor 100a fail to properly sense an approaching train. Like the primary sensor 100a, the backup sensor 100b may include at least two solid-state magneto-resistive chips with a processing chips placed on a circuit board and sealed within an enclosure. This enclosure may be buried in the earth in the right- of-way on either side of the grade crossing 56. Each backup sensor 100b is preferably positioned at a predetermined distance from the crossing 56 along the track 54. During normal operation, the primary sensor, upon proper sensing of a train 52 by at least two of the magneto-resistive chips of the primary sensor 100a, may disable, for example, operation of the backup sensor 100b. If, however, the primary sensor 100a malfunctions or the train 52 is not detected by at least two of the magneto-resistive chips of the primary sensor 100a, the backup sensor 100b provides means of activating the warning signal devices 120 before the train 52 reaches the crossing 56. For example, the approaching train 52 is detected by the first magneto-resistive chip of the primary sensor 100a.

However, due to malfunction, the second magneto-resistive chip of the primary sensor 100a fails to sense the train 52. The primary sensor 100a cannot determine the speed of the approaching train 52 in order to determine the appropriate time in which to activate the warning signal devices 120. Preferably the implementation subsystem 105 does not disable the backup subsystem. As the train 52 continues toward the crossing 56, it reaches the first of the magneto-resistive chips of the backup sensor 100b and_. is sensed. The backup sensor 100b provides a signal to the implementation subsystem 105 which may immediately activate the warning signal devices 120.

Alternately, in an exemplary embodiment the backup sensor may comprise an analog magnetometer. In this embodiment, the backup sensor may be disabled during normal operation in which the primary sensor 100a senses a train. If the primary sensor 100a malfunctions, then the backup sensor may provide means for activating the warning signal devices 120 before the train 52 reaches the crossing 56. The sensors of the present invention provide a number of advantages than those well known to the art. First, they may be installed independently of the railroad track and without requiring the resetting of the track. Also, since the sensor may be placed within a single enclosure, this allows for easier installation and maintenance. Further, since the sensors may be buried underground, they resist possible vandalism. The sensors of the present invention are suitable for self-testing. If the sensor senses a condition which may not be normal, the detection system may be placed in a fail-safe state. For example, first magneto-resistive chip senses the presence of a train, however, a second signal is not received from the second magneto-resistive chip by the processing chip, then the detection system may be placed in a fail-safe state. In another example, if a train is sensed and is determined to be traveling at a speed in excess of 200 miles per hour, then the detection system may be placed in a fail-safe state. The process as just described is represented in a flow chart in FIG. 8.

The implementation subsystem of the present invention provides a number of advantages.

If the implementation subsystem notices any anomaly in the information provided to it by the sensors, then it would cause the system to enter a fail-safe state. Also, the sensors will be in constant communication with the implementation subsystem and thus will notice any anomaly instantly. For example, if the cable connecting the implementation subsystem and the sensors was damaged, then the implementation system may be able to notice the problem right away and place the detection system in a fail-safe state. Alternatively, if the wireless connection between the sensor and the implementation subsystem has malfunctioned, then the detection system may be placed in a fail-safe state. The implementation system also may eliminate the possibility of having the warning system active when a train is heading away from a railroad crossing.

Since the implementation subsystem comprises a programmable processor, the parameters at which the train detection system will check may be altered and adjusted in order for the detection system to be suitable for different applications. For example, in an urban area, parameters may be very narrow so that the system may be placed in a fail-safe state if only the slightest deviation in the information occurs. However, in a rural area where there is little traffic, the parameters may be broad so that the detection system is placed in a fail-safe state only if a major anomaly occurs. Upon the placement of the detection system into a fail-safe state, the implementation subsystem sends a signal to the warning system to engage. Therefore, motorists and railroad personnel may be aware that a train is approaching or that there is reason for caution. Without the installation of the detection system of the present invention, when a problem occurs a railroad crossing may not be adequately protected.

In view of the above detailed description of a preferred embodiment and modifications thereof, various other modifications will now become apparent to those skilled i the art. The claims below encompass the disclosed embodiments and all reasonable modifications and variations without departing from the spirit and scope of the invention.

Claims

CLAIMS What is claimed is: 1. A self-testing train detection system, comprising: (a) a train sensor operatively associated with at least one railroad track for detecting at least one railroad car, said train detector producing at least one signal; (b) an implementing device operatively connected to said train sensor and responding to the information appropriately, wherein said implementing device is capable of engaging a warning device if said railroad car has been detected and whereby at least one of said train sensor and said implementing device are capable of placing said train detection system in a fail-safe state if at least one of said train sensor and said implementing device discovers an anomaly.

2. The self-testing train detection system as claimed in claim 1, wherein said implementing device is capable of setting parameters where if information from said train sensors is not within said parameters, then said implementing device may place said train detection system in a fail-safe state.

3. The self-testing train detection system as claimed in claim 1, wherein when at least one of said train sensor and implementation device discovers an anomaly then said implementation device is capable of engaging a warning device to alert motorists to use caution.

4. The self-testing train detection system as claimed in claim 1 , wherein said train sensor is capable of determining the presence, direction, and speed of a moving train.

5. The self-testing train detection system as claimed in claim 1, wherein when power to said train sensor is interrupted said implementing device is capable of placing the train detection system into a fail-safe state.

6. The self-testing train detection system as claimed in claim 1, wherein said train sensor and said implementation device are suitable for independent operation and installation into existing systems.

7. The self-testing train detection system as claimed in claim 1, wherein said train sensor and said implementing device are capable of constant communication between each other.

8. The self-testing train detection system as claimed in claim 7, wherein said train sensor and said implementing device are capable of constant communication between each other via a wireless link.

9. The self-testing train detection system as claimed in claim 8, wherein said wireless link is capable of providing encrypted information suitable for providing secure information between said train sensor and said implementing device.

10. The self-testing train detection system as claimed in claim 1, wherein said sensor is located adjacent to said at least one railroad track.

11. A self-testing train detection system, comprising:

(a) means for detecting the presence, direction, and speed of a moving train,

(b) means for determining if information processed by said detecting means is within prescribed parameters,

(c) means for placing said train detection system into a fail-safe state when said information processed by said train detection system is not within said prescribed parameters, and

(d) means for engaging a warning device if said moving train has been detected or said system has been placed in a fail-safe state.

12. The self-testing train detection system of claim 11, wherein said means for detecting the presence, direction, and speed of a moving train comprises a single sensor.

13. The self-testing train detection system of claim 12, wherein when an interruption in power to said sensor occurs said train detection system is placed into a fail-safe state.

14. The self-testing train detection system of claim 11 , wherein said prescribed parameters may be adjusted and altered in order to be suitable for different applications.

15. The self-testing train detection system of claim 11, wherein said means for detecting the presence, direction, and speed of a moving train and said means for determining if information processed by said detecting means is within prescribed parameters are in constant communication with each other.

16. A self-testing train detection system, comprising (a) a train sensor operatively associated with at least one railroad track capable of detecting the presence of at least one railroad car, comprising at least two solid state magneto-resistive chips and a processing chip suitable for calculating the direction and speed of said railroad car, (b) an implementing device operatively connected to said processing chip of said sensor, wherein said programmable processor of said implementing device may engage a warning device if said railroad car has been detected and when at least one of said processing chip of said sensor and said programmable processor of said implementing device discover an anomaly said detection system is placed into a fail-safe state.

17. The self-testing train detection system of claim 16, wherein said programmable processor of said implementing device is capable of having the parameters of the information said programmable processor validates to be adjusted.

18. The self-testing train detection system as claimed in claim 16, wherein said processing chip of said sensor and said programmable processor of said implementing device are in constant communication with each other.

19. The self-testing train detection system as claimed in claim 18, wherein said wherein said train sensor and said implementing device are capable of constant communication between each other via a wireless link.

20. The self-testing train detection system as claimed in claim 19, wherein said wireless link is capable of providing encrypted information suitable for providing secure information between said train sensor and said implementing device.

21. The self-testing train detection system as claimed in claim 16, wherein said train sensor and said implementation device are suitable for independent operation and installation into existing systems.

22. The self-testing train detection system as claimed in claim 16, wherein said sensor may be fitted within a single enclosure.

23. The self-testing train detection system as claimed in claim 16, wherein if said train sensor loses power then said train detection system is placed into a fail-safe state.

24. The self-testing train detection system as claimed in claim 23, wherein said implementation device engages said warning device when said train detection system has been placed in a fail-safe state.

25. The self-testing train detection system as claimed in claim 16, wherein said implementing device is capable of disengaging said warning device when said railroad car is moving away from a detection area.