Patent Application
20190308649
Disclosed embodiments are generally related to railway road crossing warning systems and, more particularly, to a system for detecting presence and movement of a railway vehicle within a detection area of a railroad track, and control of the railway road crossing warning system using a railway-vehicle sensing system electrically-decoupled from the railroad track.
Railway road crossing warning systems provide protection of crossings by detecting train presence and motion, and activating crossing warning devices such as bells, lights, crossing gate arms, within a specified time period before the arrival of a train at the road crossing. Train presence near the crossing and motion towards/away from the crossing has been traditionally detected by transmitting electrical signals on the railroad tracks. For example, train presence may be detected by receiving a voltage as propagated over the railroad track, as a transmission medium. Train motion may be determined by monitoring the current and voltage applied to the railroad track to determine the impedance of the track, from the crossing to the train. See U.S. Pat. No. 7,254,467 and International Publication Number WO 2014/059487 A1 for respective examples of railway road crossing warning systems.
One disclosed embodiment is directed a railway road crossing warning system including a railway-vehicle sensing system electrically-decoupled from a railroad track where a railway-vehicle travels. A railway road crossing control unit is responsive to at least one signal received from the railway-vehicle sensing system to process the received at least one signal and determine whether the railway-vehicle is in a detection area of the railroad track. The railway road crossing control unit is configured to activate at least one crossing warning device upon determining, based on the received at least one signal, a presence of the railway-vehicle in the detection area of the railroad track, and is further configured to deactivate said at least one crossing warning device upon determining, based on the received at least one signal, an absence of the railway-vehicle from the detection area of the railroad track.
Another disclosed embodiment is directed to a railway road crossing warning system including a railway road crossing control unit that may be selectively set by a mode selector unit to a primary mode of operation or a secondary mode of operation. In the primary mode of operation, the railway road crossing control unit is responsive to a primary activation signal received from a primary activation-signal source, such as a positive train control (PTC) system, to activate the at least one crossing warning device.
In the event the activation signal from the primary activation-signal source is not available, the railway road crossing control unit is set by the mode selector unit to the secondary mode of operation. In the secondary mode of operation, the railway road crossing control unit is responsive to at least one signal received from a secondary activation-signal source.
The secondary activation signal-source comprises a railway-vehicle sensing system electrically-decoupled from a railroad track where a railway-vehicle travels. The railway road crossing control unit is configured to process the received at least one signal and determine whether the railway-vehicle is within a detection area of the railroad track. The railway road crossing control unit is configured to activate the least one crossing warning device upon determining, based on the received at least one signal, a presence of the railway-vehicle in the detection area of the railroad track, and is further configured to deactivate the at least one crossing warning device upon determining, based on the received at least one signal, an absence of the railway-vehicle from the detection area of the railroad track.
Without limiting disclosed embodiment to any particular jurisdiction, in view of requirements mandated in the United States by the Federal Railroad Administration (FRA), the railroad industry in the United States has made a substantial investment in the infrastructure needed to implement a Positive Train Control (PTC) system. Consequently, the railroad industry has pursued applications to leverage that investment into other areas beyond the original mandate of train control to increase safety and operating efficiency in such other areas. One known application is to use train position and speed knowledge obtained by the PTC system to activate the grade crossing warning devices. This eliminates wired connections to the track rails and makes the system robust in the presence of changing weather and avoids variable electrical ballast conditions that otherwise would develop across the rails. This also makes the system impervious to alternating current (AC) electrical interference that can develop across the rails.
The inventors of the present invention have recognized some practical limitations regarding the foregoing application of the PTC system. For instance, in this application of the PTC system, there is no longer the ability to use traditional island circuits to activate the grade crossing warning devices. This is not an issue so long as the PTC system is fully functional; however, there will be instances when the PTC system may not be available for any one of a variety of reasons. Based on typical designs of current grade crossing warning systems, in these instances, one may need to rely on cumbersome techniques for activating the grade crossing warning devices in the absence of a PTC actuating signal. These techniques may involve train stoppage, which decreases efficiency of railroad operation regarding both timeliness and energy consumption. Additionally, train stoppage increases a possibility of cargo damage on the train.
In view of such recognition, the present inventors propose an innovative technical solution involving no wired connections to the track rails. The proposed technical solution maintains robustness in the presence of changing weather and avoids variable electrical ballast conditions that otherwise would develop across the rails, while providing a cost-effective and reliable backup capability for a PTC-started crossing system.
In the following detailed description, various specific details are set forth in order to provide a thorough understanding of such embodiments. However, those skilled in the art will understand that disclosed embodiments may be practiced without these specific details that the aspects of the present invention are not limited to the disclosed embodiments, and that aspects of the present invention may be practiced in a variety of alternative embodiments. In other instances, methods, procedures, and components, which would be well-understood by one skilled in the art have not been described in detail to avoid unnecessary and burdensome explanation.
Furthermore, various operations may be described as multiple discrete steps performed in a manner that is helpful for understanding embodiments of the present invention. However, the order of description should not be construed as to imply that these operations need be performed in the order they are presented, nor that they are even order dependent, unless otherwise indicated. Moreover, repeated usage of the phrase “in one embodiment” does not necessarily refer to the same embodiment, although it may. It is noted that disclosed embodiments need not be construed as mutually exclusive embodiments, since aspects of such disclosed embodiments may be appropriately combined by one skilled in the art depending on the needs of a given application.
The terms “comprising”, “including”, “having”, and the like, as used in the present application, are intended to be synonymous unless otherwise indicated. Lastly, as used herein, the phrases “configured to” or “arranged to” embrace the concept that the feature preceding the phrases “configured to” or “arranged to” is intentionally and specifically designed or made to act or function in a specific way and should not be construed to mean that the feature just has a capability or suitability to act or function in the specified way, unless so indicated.
In one non-limiting embodiment, a crossing control system 16 includes a railway road crossing control unit 18 that may be selectively set by a mode selector unit 20 (labeled S/U in the drawings) to a primary mode of operation or a secondary mode of operation. In the primary mode of operation, the railway road crossing control unit is responsive to a primary activation signal 21 received from a primary activation-signal source 22, as may be generated, without limitation, from a positive train control (PTC) system, to activate at least one crossing warning device 24, as may include bells, lights, crossing gate arms, etc.
In this primary mode, when a railway-vehicle 30, e.g., a train, approaches crossing 11, continuous location-tracking and time of arrival calculations performed by the PTC system may be used to generate primary activation signal 21 conveyed to railway road crossing control unit 18 and in turn activate crossing warning device/s 24 at an appropriate time, such as may be configured to ensure an optimum advanced activation time.
In the event primary activation signal 21 from primary activation-signal source 22 is not available, (e.g., PTC system down) railway road crossing control unit 18 is set by mode selector unit 20 to the secondary mode of operation, where railway road crossing control unit 18 is responsive to at least one signal 25 received from a secondary activation-signal source 26.
The secondary activation signal-source includes a railway-vehicle sensing system 28 electrically-decoupled from railroad track 12, where railway-vehicle 30 travels. Non-limiting examples may be railway-vehicles, such as a train, involving a series of connected railway-vehicles, that runs along railroad track 12 to transport cargo or passengers. Other non-limiting examples of railway-vehicles may be discrete railway-vehicles, such as may be used for maintenance of the railroad tracks and other applications.
As elaborated in greater detail below, railway road crossing control unit 18 may be configured to process the received signal/s 25 from railway-vehicle sensing system 28 and determine whether railway-vehicle 30 is within a detection area of the railroad track. It will be appreciated that the size and configuration of the detection area may be appropriately tailored based on the needs of a given application.
Without limitation, railway road crossing control unit 18 may be configured to activate crossing warning device/s 24 upon determining, based on the received signal/s 25, a presence of the railway-vehicle in the detection area of the railroad track. Railway road crossing control unit may be further configured to deactivate crossing warning device/s 24 upon determining, based on the received signal/s 25, an absence of railway-vehicle 30 from the detection area of the railroad track. The description below will proceed to describe various disclosed embodiments of railway-vehicle sensing system 28 that may be used alone, or in combination, if so desired.
In one non-limiting embodiment, as train 30 approaches crossing 11, as schematically illustrated in
As train 30 passes continues to pass over crossing 11, as schematically illustrated in
As train 30 continues to eventually depart from the crossing, as schematically illustrated in
In one non-limiting embodiment, as train 30 approaches crossing 11, as schematically illustrated in
As train 30 continues to pass over crossing 11, as schematically illustrated in
As train 30 continues to eventually depart from the crossing, as schematically illustrated in
In one non-limiting embodiment, as railway vehicle 30 approaches crossing 11, as schematically illustrated in
As train 30 continues to pass over the crossing, as schematically illustrated in
As train 30 departs from the crossing, as schematically illustrated in
In operation, disclosed embodiments offer an innovative technical solution in railway road crossing warning system that involves no wired connections to the track rails. Disclosed embodiments maintain operational robustness in the presence of changing weather and avoid variable electrical ballast conditions that otherwise could develop across the rails, while providing a cost-effective and reliable backup capability for a PTC-started crossing system.
While embodiments of the present disclosure have been disclosed in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the scope of the invention and its equivalents, as set forth in the following claims.
