Patent Application
20090277998
The field of this disclosure relates generally to railways and, more particularly, to methods and systems for detecting railway vacancy.
It is often desirable to designate a given railway segment as being either occupied or vacant to enable a determination to be made as to whether a railcar can enter that particular railway segment. To render a vacancy determination as to a particular railway segment, many known vacancy detection systems use sensing devices that, after detecting a railcar, report the presence of the railcar to a single point accumulation device. Known accumulation devices evaluate the sensing events as they occur to enable a continuous, real-time determination as to the vacancy of the entire railway segment to be performed.
Communication between a sensing device and an accumulation device may be susceptible to interruption, such as, for example, from power failures, signal grounding, and/or electromechanical interference at the sensing device. As such, at least some known vacancy detection systems that rely on continuous, real-time communication between each of the sensing devices and the accumulation device may be susceptible to either an inability to render a designation and/or a possibility of rendering an erroneous designation regarding the status of the railway segment because the detection system cannot reconcile sensing events that may have occurred at one or more sensing devices during the communication interruption(s).
Accordingly, it would be desirable to have a detection system that can reconcile a count of railcars present on the railway after an interruption in communication between the accumulation device and one or more sensing devices.
In one aspect, a method for detecting railway vacancy is provided. The method includes sensing, at a remote sensing unit positioned proximate to a railway, a presence of a railcar traversing the railway. The method also includes storing, in real-time, at the remote sensing unit, a sensing event indicative of the sensed presence of the railcar traversing the railway and transmitting, asynchronously from the time at which the presence of the railcar was sensed at the remote sensing unit, the stored sensing event to a master accumulation unit.
In another aspect, a system for detecting designated vehicle pathway vacancy is provided. The system includes a master accumulation unit and a remote sensing unit in communication with the master accumulation unit. The remote sensing unit is positioned proximate to a pathway, and the remote sensing unit is configured to sense a presence of a vehicle traversing the pathway. The remote sensing unit is also configured to store, in real-time, at the remote sensing unit, a sensing event indicative of a sensed presence of a vehicle traversing the pathway and to transmit, asynchronously from the time at which the presence of the vehicle was sensed, the stored sensing event to the master accumulation unit.
In another aspect, a method for detecting railway vacancy is provided. The method includes receiving, at a master accumulation unit asynchronously from a time at which a presence of a railcar was sensed by a remote sensing unit, a sensing event indicative of the sensed presence of the railcar traversing the railway and rendering a designation as to a vacant or occupied state of the railway.
The following detailed description illustrates exemplary methods and systems for detecting railway vacancy by way of example and not by way of limitation. The description should clearly enable one of ordinary skill in the art to make and use the disclosure, and the description describes several embodiments, adaptations, variations, alternatives, and uses of the disclosure, including what is presently believed to be the best mode of carrying out the disclosure. The disclosure is described herein as being applied to a preferred embodiment, namely, methods and systems for detecting railway vacancy. However, it is contemplated that this disclosure has general application to detecting a presence of any designated vehicle (e.g., an automobile, a marine vessel, etc.) along any pathway and may be applicable in a broad range of transportation systems and/or a variety of other commercial, industrial, and/or consumer applications.
In the exemplary embodiment, MAU 104 is implemented as a part of a computer system (not shown). The computer system, or any component thereof, may be housed within an enclosure that is proximate to railway R, and/or that is located remotely from railway R. The computer system may include a computer, an input device, a display unit, and an interface, for example, to access the Internet. The computer system may also include a processor, which may be connected to a communication bus. The computer may include a memory, which may include a Random Access Memory (RAM) and a Read Only Memory (ROM), as well as a storage device, which may be a hard disk drive or a removable storage drive such as a floppy disk drive, an optical disk drive, and so forth. The storage device is configured to load computer programs and/or other instructions into the computer system. As used herein, the term “processor” is not limited to only integrated circuits referred to in the art as a processor, but broadly refers to a computer, a microcontroller, a microcomputer, microprocessor, a programmable logic controller, an application specific integrated circuit and any other programmable circuit.
The computer system executes instructions, stored in one or more storage elements, to process input data. The storage elements may also hold data or other information, as desired or required, and may be in the form of an information source or a physical memory element in the processing machine. The set of instructions may include various commands that instruct the computer system to perform specific operations, such as the processes of a method. The set of instructions may be in the form of a software program. The software may be in various forms, such as system software or application software. Further, the software may be in the form of a collection of separate programs, a program module within a larger program, or a portion of a program module. The software may also include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, to results of previous processing, or to a request made by another processing machine.
As used herein, the term ‘software’ includes any computer program that is stored in the memory, to be executed by a computer, which includes RAM memory, ROM memory, EPROM memory, EEPROM memory, and non-volatile RAM (NVRAM) memory. The memory types mentioned above are only exemplary and do not limit the types of memory used to store computer programs.
RSU controller 206, in the exemplary embodiment, includes an event counter and/or a time-keeper, such that RSU controller 206 performs real-time counting of sensing events and/or real-time storage of time-stamped sensing events in RSU memory 204 and such that RSU controller 206 transmits to MAU 104, asynchronously from the time at which a presence of a railcar was sensed along Railway R, the counted and/or stored sensing event associated with the sensed presence. As used herein, the term real-time refers to outcomes occurring a substantially short period (i.e., a short amount of time has elapsed) after a change in the inputs affect the outcome, with no intentional delay. As used herein, the term asynchronously means that the time of transmission is not a direct function or result of when the event is sensed, but instead may be carried out at a later time.
In one embodiment, RSU sensor 202 is positioned proximate to entry point 106 and/or exit point 108 of one of railway zones (A, B, C, D, E, and/or F), to enable RSU sensor 202 to detect a presence of an object, such as, for example, a railcar axle and/or a railcar wheel, that enters and/or exits railway zone (A, B, C, D, E, and/or F). In one embodiment, RSU sensor 202 may be an electrical circuit and/or an optical sensor, such as, for example, an infra-red sensor. Alternatively, RSU sensor 202 may be any sensing device that enables RSU 102 to function as described herein. In the exemplary embodiment, RSU 102 transmits signals to MAU 104 and/or receives signals from MAU 104 via RSU controller 206 using any suitable communication device and/or communication medium, such as, for example, a copper cable, a fiber optic cable, a radio frequency or other method of wireless communication, and/or any combination thereof.
In the exemplary embodiment, RSU 102 is solar powered. Alternatively, RSU 102 may be powered using any suitable power source, across any suitable medium, such as hardwiring, for example. In one embodiment, RSU 102 may use and/or may be built into a railway switch machine (not shown) that is positioned proximate to railway R. For example, at least one operation of RSU controller 206 may be performed by an evaluator (not shown) housed within the railway switch machine. In such an embodiment, RSU 102 communicates with MAU 104 using either a communication device and/or a communication medium that is used by a railway switch controller (not shown). In an alternative embodiment, RSU 102 may be an independent unit that is installed separately from the railway switch machine.
After receiving 304 the offset quantity of railcars, MAU 104 enters into an idle operating mode and prompts 306 each RSU 102 to enter into a sensing mode. In the sensing mode, MAU 104 waits to receive a signal from each RSU 102 that is indicative of a presence of a railcar on railway R. As described in more detail below, after entering into the sensing mode, each RSU 102 transmits, at predetermined time intervals, a signal to MAU 104 indicative of each sensed presence of a railcar on railway zone (A, B, C, D, E, and/or F). Upon receiving 308 a signal from each RSU 102, at the expiration of each time interval, MAU 104 evaluates the received signal from each RSU 102, reconciles 310 a count of railcars present on each railway zone (A, B, C, D, E, and/or F), and renders 310 a designation as to whether each railway zone (A, B, C, D, E, and/or F) is vacant or occupied. In an alternative embodiment, MAU 104 iteratively requests a signal from each RSU 102 at the expiration of each time interval. In the exemplary embodiment, if MAU 104 does not receive 308 a signal from one or more RSU 102 (hereinafter referred to as “a lost RSU”) within a predetermined time period, MAU 104 defaults 312 to declaring a predetermined state designation (e.g., an “occupied” state designation) for the specific railway zone (A, B, C, D, E, or F) that was being monitored by the lost RSU 102.
In the exemplary embodiment, if an interruption in communication between MAU 104 and the lost RSU 102 exceeds 314 a predetermined time period, MAU 104 declares 316 an unrecoverable out-of-communication fault in system 100. Such a declaration 316 causes operation 300 to re-initiate 302 (i.e., reset and re-synchronize each RSU 102). After re-initiating 302 operation 300, each railway R is re-inspected by an operator, and the offset quantity of railcars present on each railway zone (A, B, C, D, E, and F) is re-input into MAU 104 prior to MAU 104 re-prompting 306 each RSU 102 to re-enter the sensing mode. For example, if MAU 104 declares 316 an unrecoverable out-of-communication fault in system 100, a railway operator may inspect railway R and determine that twelve railcars with four axles each, twelve railcars with two axles each, and three railcars with twelve axles each, are present on railway zone A. In such an example, an offset quantity of one hundred and eight axles is input into MAU 104. In the exemplary embodiment, if MAU 104 declares 316 an unrecoverable out-of-communication fault in system 100, MAU 104 maintains the predetermined default state designation (e.g., the “occupied” state designation) for that specific railway zone (A, B, C, D, E, and/or F) that was being monitored by the lost RSU 102 until system operation 300 is re-initiated 302.
If an interruption in communication between MAU 104 and the lost RSU 102 does not exceed 314 the predetermined time period, MAD 104 evaluates the received signal from each RSU 102, including the lost RSU 102, after the communication is reestablished. A count of railcars present on each railway zone (A, B, C, D, E, and/or F) is then reconciled 310, and a designation as to a vacant or an occupied state of each railway zone (A, B, C, D, E, and F) is rendered 310. After rendering 310 a designation as to whether each railway zone (A, B, C, D, E, and F) is vacant or occupied, MAU 104 re-enters the idle mode and re-prompts 306 each RSU 102 to re-enter the sensing mode. As described below, after communication between MAU 104 and the lost RSU 102 has been restored, MAU 104 relies upon historical information that was transmitted to MAU 104 by each RSU 102, including the lost RSU 102, either before and/or after the restoration in communication, to reconcile 310 a count of railcars present on each railway zone (A, B, C, D, E, and/or F).
In one embodiment, after each designation by MAU 104 that a railway zone (A, B, C, D, E and/or F) is vacant, MAU 104 resets either a counter stored within the MAU 104, and/or the counter stored within each RSU 102 that monitors the railway zone (A, B, C, D, E, and/or F) that was designated vacant. Because each RSU counter has a limited storage capacity, RSU 102 may reach a maximum storage capacity if railway zone (A, B, C, D, E, and/or F) has not been declared vacant in a given period of time. If an RSU 102 reaches its maximum counting capacity, the RSU counter automatically rolls-over and begins counting from a base value (e.g., zero). For example, if the RSU counter has a binary storage capacity (e.g., the RSU counter can only store 1024 counts) and if the RSU counter reaches the binary storage capacity limit, the RSU counter automatically rolls over to avoid missing a count. In one embodiment, MAU 104 is programmed to account for the roll-over of the RSU counter when MAU 104 reconciles 310 the count of railcars present on each railway zone (A, B, C, D, E, and/or F).
In the exemplary embodiment, RSU controller 206 time-stamps each sensing event received 404 from RSU sensor 202. RSU controller 206 is programmed to store 406, in RSU memory 204, as a batch of sensing events, every time-stamped sensing event that occurs during a given time interval. As such, RSU 102 maintains a historical record of every time-stamped sensing event that occurred during each expired time interval.
If, after storing 406 each sensing event, RSU controller 206 determines that the predetermined time interval has not expired 408, RSU controller 206 waits to receive 404 another signal from RSU sensor 202. Upon expiration 408 of each time interval, RSU controller 206 searches 410 for an open communication with MAU 104. If an open communication exists, RSU 102 transmits 412 at least one batch of time-stamped sensing events to MAU 104. In one embodiment, RSU controller 206 is also programmed to transmit 412, after each expired time interval, a pre-selected quantity of batches from previously expired time intervals. As such, MAU 104 can maintain a historic record of sensing events for use in reconciling 310, in the event of a communication loss between MAU 104 and RSU 102, the number of railcars that entered and/or exited each railway zone (A, B, C, D, E, and/or F) at any given time prior to, and/or during, the communication loss. If RSU controller 206 searches 410 for an open communication with MAU 104 and determines that the communication has been interrupted, RSU controller 206 re-initiates sensing mode 400.
In the exemplary embodiment, each RSU time-keeper is time synchronized with every other RSU time-keeper, such that each RSU 102 transmits batches of sensing events to MAU 104 at substantially the same time. Alternatively, a first grouping of RSUs 102 that monitors a first railway zone (A, B, C, D, E, or F) is time synchronized to follow a first time interval, and a second grouping of RSUs 102 that monitors a second railway zone (A, B, C, D, E, or F) is time synchronized to follow a second time interval. Accordingly, in such an embodiment, the first grouping of RSUs 102 and the second grouping of RSUs 102 keep time on different intervals and transmit batches of sensing events to MAU 104 at different times, given that the first and second time intervals expire at different times.
As will be appreciated by one skilled in the art and based on the foregoing specification, the above-described embodiments of the operations of the above-described system 100 for detecting railway vacancy may be implemented using computer programming or engineering techniques including computer software, firmware, hardware or any combination or subset thereof that is configured to control various components of a system for detecting railway vacancy. Any resulting program, having computer-readable code means, may be embodied or provided within one or more computer-readable media, thereby making a computer program product, i.e., an article of manufacture, according to the discussed embodiments of the invention. The computer readable media may be, for example, but is not limited to, a fixed (hard) drive, diskette, optical disk, magnetic tape, semiconductor memory such as read-only memory (ROM), and/or any transmitting/receiving medium such as the Internet or other communication network or link. The article of manufacture containing the computer code may be made and/or used by executing the code directly from one medium, by copying the code from one medium to another medium, or by transmitting the code over a network.
The methods and systems described herein facilitate storing sensing events locally, at a remote sensing unit, during an interruption in communication between the remote sensing unit and a master accumulation unit and facilitate transmitting the sensing events stored during the communication interruption to the master accumulation unit upon restoration of communication, thereby adding analysis and communications protocol to facilitate allowing a railway vacancy detection system to reconcile lost communication with a remote sensing unit. The methods and systems described herein also facilitate compensating for errors in timing and data such that a number of remote sensing units is facilitated being expanded in both complexity and distance, thereby facilitating providing cost-effective and reliable railway vacancy detection in virtually any environment.
Exemplary embodiments of methods and systems for detecting railway vacancy are described above in detail. The methods and systems for detecting railway vacancy are not limited to the specific embodiments described herein, but rather, components of the methods and systems may be utilized independently and separately from other components described herein. For example, the methods and systems described herein may have other industrial and/or consumer applications and are not limited to practice with only railway systems as described herein. Rather, the present invention can be implemented and utilized in connection with many other industries.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
