Patent Publication Number: US-2005121971-A1

Title: Serial train communication system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is related to and claims priority from U.S. Provisional Patent Application Ser. No. 60/527,505 filed on Dec. 5, 2003. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates, in general, to a train communication system and, more particularly, the instant invention relates to a serial train communication system for a railway train consisting of at least one locomotive and a predetermined plurality of railway cars coupled thereto and, yet more particularly, the invention relates to a serial train communication system utilizing sound transmission and, still more particularly, the present invention relates to a serial train communication system utilizing sound transmission for controlling brakes of the railway car.  
     BACKGROUND OF THE INVENTION  
      The following background information is provided to assist the reader to understand the environment in which the invention will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless specifically stated otherwise in this document.  
      In an attempt to improve operation of railway cars, various Railroads have been deploying and testing new systems and methods of controlling various equipment installed on such railway cars in general and, particularly, controlling main pneumatic braking systems of the railway car. The two systems that have received the most attention are an Electrically Controlled Pneumatic (EP) braking system and Electronically Controlled Pneumatic (ECP) braking system.  
      An EP braking system uses several train wires to operate individual valves to control brakes. While offering a direct brake release and improved air pressure consumption, most of these systems use a second train line for main reservoir air supply and they do not have built-in two-way communication capabilities. Furthermore, the EP braking system is primarily used in rapid transit urban operations and long haul passenger trains in combination with electric traction and multiple unit control.  
      An ECP braking system has been introduced in an attempt to overcome the drawbacks of the air brake system on long freight trains. The ECP braking system, a highly integrated braking control system, uses an electronic signal along an on-train communication network to initiate braking applications and releases. It also enables a two-way communication between components of the braking system and an onboard computer providing a train Engineer with the information on the status and condition of such components.  
      To apply the brakes, the Engineer utilizes the lead control unit disposed in a vicinity of the engineer&#39;s console to select the amount of desired brake cylinder pressure (or percentage of braking effort). The lead control unit codes the selected pressure and broadcasts a brake command in a data form to control units disposed in each ECP braking system on all railway cars. This brake command enables a supply of the compressed air from reservoirs to the brake cylinder in each ECP braking system until the desired cylinder pressure is achieved. A control unit continuously monitors brake cylinder pressure against leakage and maintains the desired pressure.  
      To enact either partial or a full brake release, the Engineer selects a new desired brake pressure level. Again, the brake command is broadcast and results in a reduction of the brake cylinder pressure within each ECP braking system. If the Engineer requires only a partial reduction of the braking effort, he can increase the braking pressure again as needed without performing a full brake release first. The control unit on each car further constantly monitors brake pipe, reservoir tank and brake cylinder pressures.  
      When braking commands are not being transmitted, operational status information is being broadcast between the lead and last car in the train consist and is being monitored by each railway car control unit within such train consist.  
      The main expected advantage of the ECP braking system is a reduced braking distance, in return allowing higher train speeds, improved fuel efficiency and improved rail system throughput. The subsequent improved train handling reduces slack action, breakaways and derailment thus potentially leading to a safer and easier train operation, reduction in maintenance of the key components, such as draft gears, and reduction in the operating crew size.  
      There are also several disadvantages of the current ECP braking systems causing limited application within railways.  
      In a first aspect, there is a significant voltage drop over an entire car freight train consist. In order to have at least 12 Volts on the last car, the first car must have at least 220 Volts resulting in a voltage drop of about 200 Volts. An additional disadvantage is the use of heavy 6 to 8 gage wire, potentially shielded from transients and other noise inducing factors.  
      In a second aspect, a greater brake shoe wear has been documented due to a more frequent use of the brakes.  
      In a third aspect, a simultaneous brake operation is required to minimize problems related to draft/buff conditions within the railway train.  
      In a fourth aspect, ECP braking system requires significant capital expenditures due to high implementation costs. Even though the system was first introduced in 1993, the Return On Investment (ROI) has not yet been fully realized.  
      Several other communication systems have their inherent disadvantages. For example, use of RF communication is impeded by problems of communication with wrong cars within or outside of its own train consist. Infrared and optical based communication systems suffer from the dirty and dusty environment degrading the operational capabilities of the infrared and optical sensor components respectively.  
      Additional disadvantages with electrical based communication and control systems are associated with the need to route new electrical wires, starting with the locomotive, as well as route these wires in extremely close proximity to the air brake hose. Such air brake hose, as is well known, drops low to the ground when not properly adjusted hitting the objects at the railroad crossings and thus severing air and electrical connection.  
      As it can be seen from the above discussion, there is a need for an improved communication system for freight railway trains requiring smaller capital expenditures and offering a more reliable operation.  
     SUMMARY OF THE INVENTION  
      A train communication system of the present invention overcomes difficulties associated with other types of train communication systems by employing ultrasonic transmission means for transmitting and receiving a sound wave of a predetermined frequency, wherein the sound wave is associated with at least a command signal. The ultrasonic transmission means have various advantages. They are capable of detecting small objects over long operating distances. Further, ultrasonic transmission means are impervious to target materials, surface and color and such ultrasonic transmission means are resistant to external disturbances such as vibration, infrared radiation, and ambient noise and EMI radiation. Additionally, they are not affected by dust, dirt or high-moisture environments and they have a virtually unlimited maintenance-free lifespan.  
      The serial train communication system comprises a power source and a controller coupled to such power source. The power source is a simple battery due to the low power requirements. The controller is capable of executing a predetermined software algorithm. The controller and power source can be mounted in any place or to any apparatus of the railway car.  
      The ultrasonic transmission means includes a transmitter mounted at one end of the railway car or the locomotive and a receiver mounted at the opposite end of the railway car or the locomotive in alignment with the transmitter. Both the receiver and transmitter are coupled to the controller and to the power source.  
      A command signal from the locomotive cab causes the controller installed on the locomotive to enable its transmitter to transmit a sound wave of a predetermined frequency which is above a range of human hearing in a first direction and such sound wave is received by the receiver on the railway car producing the output signal to its controller. The controller then enables the transmitter mounted at the opposite end of the railway car to transmit the sound way in the first direction toward the next car, thus establishing a serial train communication.  
      The controller may also be coupled to various apparatuses disposed on the railway car, such as brakes or hand brakes, for enabling operation thereof upon receiving an output signal from the receiver.  
      Further, the ultrasonic transmission means includes a transceiver in combination with the transmitter and the receiver which enables transmission of the sound wave in a second direction toward the locomotive for providing an operational status feedback signal to the locomotive cab.  
      The transceivers are mounted within an air brake line having a plurality of air brake pipes and air brake hoses which run along the entire railway train for operation of the brake systems disposed within a wheel set of the railway car or the locomotive.  
      Since the train communication system is battery powered and uses non-contact ultrasonic transceivers for communication, each system is a stand alone system enabling ease of retrofit onto existing railway cars and reduction of capital expenditures associated with other types of communication systems.  
     OBJECTS OF THE INVENTION  
      It is a primary object of the present invention to provide a serial train communication system utilizing a sound transmission means.  
      It is another object of the present invention to provide a serial train communication system utilizing a sound transmission means which is unaffected by environmental factors.  
      It is yet another object of the present invention to provide a serial train communication system utilizing a sound transmission means which enables operational control of apparatuses locally mounted on a railway car.  
      It is a further object of the present invention to provide a serial train communication system utilizing a sound transmission means which can be integrated with control equipment and an event recorder located in a locomotive cab.  
      It is yet a further object of the present invention to provide a serial train communication system utilizing a sound transmission means which has capabilities for future interface with EP and ECP braking systems.  
      It is additional object of the present invention to provide a serial train communication system utilizing a sound transmission means which requires reduced capital investment and expenditure.  
      Although a number of objects and advantages of the present invention have been described in some detail above, various additional objects and advantages of the serial train communication system of the present invention will become more readily apparent to those persons who are skilled in the art from the following more detailed description of the invention, particularly when such detailed description of the invention is taken in conjunction with both the attached drawing figures and with the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a diagrammatic representation of a prior art railway train consisting of a locomotive and a plurality of railway freight cars;  
       FIG. 2  is a diagrammatic representation of a serial train communication system of one embodiment of the present invention showing installation of the ultrasonic sensors at each end of a railway car;  
       FIG. 3  is a schematic representation of a serial train communication system of  FIG. 2 , showing a component interface;  
       FIG. 4  is a diagrammatic representation of a serial train communication system of another embodiment of the present invention showing attachment of the ultrasonic transceivers at each end of the railway car and showing attachment of the controller and the power source;  
       FIG. 5  is a schematic representation of a serial train communication system of  FIG. 4 , showing a component interface and an interface with an automatic set and release hand brake; and  
       FIG. 6  is a diagrammatic representation of a serial train communication system of yet another embodiment of the present invention showing installation of the ultrasonic transceivers within an air brake pipe.  
    
    
     DETAILED DESCRIPTION OF VARIOUS PREFERRED AND ALTERNATIVE EMBODIMENTS OF THE INVENTION  
      Prior to proceeding with the more detailed description of the invention it should be noted that for the sake of clarity and understanding the invention, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the attached drawing Figures, unless otherwise noted.  
       FIG. 1  shows a railway train, generally designated  10 , having at least one locomotive  12  with a cab  13  and a predetermined plurality of railway cars  14  through  18  serially coupled to such at least one locomotive  12 . As can be understood, railway trains and, particularly, railway freight trains can operate many more cars than shown, and typically, one-hundred to two-hundred and fifty railway freight car trains are not uncommon. While  FIG. 1  only depicts three railway cars  14 - 18  and one locomotive  12 , it is to be understood that multiple railway cars of any length can be used in practicing the invention.  
      The at least one locomotive  12  and each railway freight car  14 - 18  is equipped with a pair of pockets  20  disposed at each end thereof. Each end pocket  20  houses a coupling means  22  for interconnecting such at least one locomotive  12  and predetermined plurality of freight railway cars  14 - 18  into a railway train  10 . The coupling means  22  may be of any well known coupler, articulated coupling, or drawbar.  
      An air brake line  24  consisting of rigid pipe portions  26  and flexible hose portions  28  runs through the entire length of the railway train  10 , starting with the at least one locomotive  12 , for providing an air supply and a brake signal to a plurality of brake systems  30  disposed within a wheel set  29 , which are well known in the art.  
      Each freight railway car  14  through  18  is generally provided with a hand brake  32  having a connection with the brake system  30  via a chain  34  for manually applying such brake system  30  when the railway train  10  is in a parked condition and air supply is not available to the plurality of brake systems  30 .  
      A serial train communication unit, generally designated  50 , of one embodiment is best shown in  FIGS. 2 and 3  and comprises a power source  52 , a controller  54  electrically coupled to the power source  52  via at least one electrical connection  55 , a first sound transmission means  64  rigidly attached to a first end pocket  20  and a second sound transmission means  66  rigidly attached to an opposed second end pocket  20 , such second sound transmission means  66  being aligned with such first sound transmission means  64 . Both the first and second sound transmission means  64  and  66  respectively are electrically coupled to the controller  54  via a pair of control wires  56  and are coupled to the power source via a pair of power wires  58 . In such embodiment, the first sound transmission means  64  is preferably an ultrasonic transmitter  64  capable of transmitting a sound wave  68  of a predetermined frequency above an upper limit of a human hearing and the second sound transmission means  66  is an ultrasonic receiver  66  capable of receiving such sound wave  68 .  
      The controller  54 , preferably, is a microprocessor  54  capable of executing a predetermined software logic algorithm. A power source  52 , preferably, is a simple battery due to the low power requirements of the microprocessor  54  and the ultrasonic transmitter and receiver  64  and  66  respectively. The control wires  56  are of a predetermined size, preferably in a range of  14 - 16  GA, since, as it well known, no significant voltage drop occurs during electrical communication between the controller  54  and the ultrasonic transmitter and receiver  64  and  66  respectively.  
      In reference to  FIG. 2 , which at least partially shows a pair of adjacent railway cars  14  and  16 , the ultrasonic transmitter  64  is rigidly attached to the first end pocket  20  of each railway car  14 ,  16  and the ultrasonic receiver  66  is rigidly attached to the second end pocket  20  of each railway car  14 ,  16 . As is well known, a generally fixed distance between opposed end pockets  20  enables establishing a predetermined distance between the ultrasonic transmitter  64  and the ultrasonic receiver  66 .  
      In operation, the ultrasonic transmitter  66  mounted on the second end pocket of the first railway car  14  will receive the sound wave  68  having such predetermined frequency from the at least one locomotive  12 . The ultrasonic receiver  66  will then provide an output signal to the controller  54  on the first railway car  14  via the control wire  56  where the output signal will be processed according to the predetermined software logic algorithm. The controller  54  on the first railway car  14  will enable the ultrasonic transmitter  64  mounted on the first end pocket thereof to send the sound wave  68  in a direction  70  toward the ultrasonic receiver  66  mounted on the second end pocket of the second railway car  16 . The ultrasonic receiver  66  will then provide an output signal to the controller  54  on the second railway car  16  via the control wire  56  where the output signal will be processed according to the predetermined software logic algorithm. The controller  54  on the second railway car  16  will enable its own ultrasonic transmitter  64  (not shown) mounted at the opposite end thereof to transmit the sound wave  68  in the direction  70  toward the next railway car  18  thus enabling a communication within the railway train  10 , which is serial in its nature.  
      The serial train communication unit  50  disposed within the at least one locomotive  12  is generally referred to as a lead unit and is coupled to a control equipment including but not limited to a brake control lever and an event recorder located in the locomotive cab  13  which are not shown but are well known in the art.  
      Advantageously, the operation of the ultrasonic transmitter  64  and the ultrasonic receiver  66  is resistant to external disturbances such as vibration, infrared radiation, ambient noise and EMI radiation and is not affected by dust, dirt or high-moisture environments. Thus, the control wires  56  will not require shielding.  
      It will be understood that the ultrasonic transmitter  64  and the ultrasonic receiver  66  may be mounted directly to a wall structure of the first and second railway cars  14  and  16  respectively in an alignment with each other.  
      Employment of a dedicated power source  52  eliminates routing of the electrical wires associated with EP and ECP braking systems thus simplifying installation effort, reducing capital expenditures and providing a more reliable operation.  
       FIGS. 4 and 5  show another embodiment of the present invention, wherein a first sound transmission means  60  is a first ultrasonic transceiver rigidly attached to the first end pocket  20  of each railway car  14 ,  16  and a second transmission means  61  is a second ultrasonic transceiver rigidly attached to the second end pocket  20  of each railway car  14 ,  16  in alignment with such first sound transmission means  60  and being disposed at the predetermined distance thereto.  
      Each ultrasonic transceiver  60 ,  61  comprises the transmitter member  64 , and the receiver member  66  and may include a housing  62  having a mounting means (not shown).  
      In operation, the transmitter member  64  of the first ultrasonic transceiver  60  mounted on the first end pocket of the railway car  14  will send the sound wave  68  having the predetermined frequency above the upper limit of human hearing in a first direction  70  toward the receiver member  66  of the second ultrasonic transceiver  61  mounted on the second end pocket of the second railway car  16 . The first ultrasonic transceiver  60  will then receive and process a returned sound echo produced by the receiver member  66  in a second direction  72 . The first ultrasonic transceiver  60  will then provide an output signal to the controller  54  on the first railway car  14  via the control wire  56  where the output signal will be processed according to the predetermined software logic algorithm. It will be understood that the return sound echo will be associated with the presence of such receiver member  66  and, more particularly, will be associated with presence of the railway car  16 . Accordingly, the second ultrasonic transceiver  61  will send its own sound wave toward the first ultrasonic transceiver  60  in the second direction  72  receiving a feedback echo sound in the first direction  70  and providing an output signal to the controller  54  mounted on the second railway car  16 . By measuring a time increment for the sound echo to return and knowing a speed of sound, each controller  54  can determine the distance between the pair of ultrasonic transceivers  60  and  61  to validate a communication therebetween, and, more importantly, to validate the communication between a pair of adjacent railway freight cars  14  and  16 .  
      In a like manner, the controller  54  on the first railway car  14  will enable a second ultrasonic transceiver  61  mounted at the opposite end thereof to transmit the sound wave  68  in the second direction  72  toward the at least one locomotive  12 . The controller  54  on the second railway car  16  will enable a first ultrasonic transceiver  60  mounted at the opposite end thereof to transmit the sound wave  68  in the first direction  70  toward the next railway car  18  thus enabling a communication within the train  10 , which is serial in its nature. It will be understood that the communication in the first direction  70  will provide a command signal from the at least one locomotive  12  to each railway car  14 - 18 , while the communication in the second direction  72  will provide an operational status feedback signal to the at least one locomotive  12 .  
      It will be appreciated that the serial train communication unit  50  containing ultrasonic transceivers  60 ,  61  having both the transmitter member  64  and the receiver member  66  enables two-way communication between the at least one locomotive  12  and the predetermined plurality of the railway cars  14  through  18 . Such two-way communication is advantageous, where the railway cars  14  through  18  are frequently interchanged between different trains  10  or where the status feedback signal is required for monitoring system performance from the locomotive cab  13 .  
      In reference to  FIG. 4 , the controller  54  and the power source  52  are attached to an underside surface of the railway car  14  intermediate each end thereof for ease of connectivity to various apparatuses disposed thereabout.  
       FIGS. 4 and 5  further show an application of the serial train communication unit  50  of the present invention in combination with an Automatic Set and Release (ASR) hand brake assembly  100  taught in U.S. Pat. No. 6,709,068 entitled “Automatic Set and Release Hand Brake Pneumatic Circuit Design II/Automatic Application Function” and in U.S. Pat. No. 6,394,559 entitled “Control Apparatus for the Application and Release of a Hand Brake, both owned by the assignee of the present invention. The teachings of U.S. Pat. No. 6,709,068 and U.S. Pat. No. 6,394,559 are incorporated herein by reference thereto.  
      The ASR hand brake  100  is connected with the brake system  30  via a chain  34 . The ASR hand brake  100  has an apply valve  110  and a release valve  130  disposed in a control circuit and electrically coupled to the controller  54  with a plurality of auxiliary control wires  59 . To apply the ASR hand brake  100 , the engineer issues an apply signal from the locomotive cab  13 , which is communicated through the plurality of ultrasonic transceivers  60  in a manner described supra to each railway car  14  through  18 . Each controller  54  upon receiving such apply signal, initiates activation of the apply valve  110  electrically coupled thereto to wind up the chain  34  and engage the brake system  30  with the wheel set  29 . Accordingly, a release signal sent from the locomotive cab  13  will be received by the controller  54  to initiate the release valve  130  in order to release the chain  34  and subsequently disengage the brake system  30  from the wheel set  29 .  
      An apply sensor  120  attached to the ASR hand brake  100  and electrically coupled to the controller  54  may be included to confirm winding of the chain  34 . Accordingly, a release sensor  140  may be included to confirm release of the chain  34 . Such status information may be communicated via the serial train communication unit  50  to the event recorder (not shown) located in the locomotive cab  13 .  
      It will be appreciated that the predetermined software algorithm executed by the controller  54  will be modified to enable interface with the ASR hand brake  32 . Accordingly, such predetermined software algorithm may be further modified to enable interface with other various equipment installed on the railway car, including EP and ECP braking systems.  
      In reference to  FIG. 5 , the controller  54  and the power source  52  may be rigidly attached to the ASR hand brake  100  thus further reducing installation costs and capital expenditures associated with adapting the railway car  14  for mounting of such components.  
       FIG. 6  illustrates yet another embodiment of the present invention wherein the ultrasonic transceiver  60  is installed within a housing  76  disposed within a portion of the brake pipe  26  enabled by, as it generally known, their relative small size. Such embodiment will be particularly advantageous in employing a single ultrasonic transceiver  60  within each railway car  14 - 18  and will be further advantageous in communicating within a mixed configuration of railway cars in the railway train  10 , wherein only a partial quantity of railway cars is equipped with the serial train communication unit  50  of the present invention.  
      Those skilled in the relevant art would easily understand that the aforementioned serial train communication system is capable of controlling and monitoring operation of the brake system  30  by coupling to a control means thereof as well as controlling and monitoring other apparatuses found on a typical railway car in a manner as described supra for application of the ASR hand brake  100 . The additional status information collected and communicated to the cab event recorder (not shown) may include: brake cylinder piston travel measurement, p/m worn brake shoe detection, truck derailment detection, brake pipe pressure, brake cylinder pressure, hot bearing detection/ confirmation, p/m truck/wheel set maintenance needs, and other operational parameters.  
      It will be further understood that ultrasonic transceivers  60 , the controller  54  and the power source  52  may be mounted on any such apparatus as best suitable for a particular application.  
      Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It will be understood that variations, modifications, equivalents and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.  
      For example, the ultrasonic transceiver  60  may be installed within an air hose assembly  28  further reducing retrofit costs of the existing railways cars  14 - 18 .