Abstract:
A system and method for automatically establishing a wireless network between multiple units in a locomotive consist. A leading locomotive may transmit through the MU cable a ping signal to a remote unit that is directly or indirectly connected to the leading locomotive. When the remote unit replies to the ping, the leading locomotive may transmit through the MU cable network setup information to the remote unit. The remote unit may automatically setup its network controls using the data provided by the leading locomotive to communicate with the leading locomotive through a wireless network.

Description:
TECHNICAL FIELD 
     The present disclosure relates to locomotive consist communication and networking. More particularly, the present disclosure relates to systems and methods for automatically synchronizing a network of multiple locomotives or units in a locomotive consist using an Internet Protocol (IP) address associated with each MU. 
     BACKGROUND 
     A locomotive is a railway vehicle that provides the motive power for a train. Generally, a locomotive carries no payload of its own, and its sole purpose is to move the train along the tracks. In contrast, self-propelled payload-carrying vehicles may be referred to as motor coaches or railcars. 
     Locomotives can be operated as single traction engines to pull or push strings of non-powered cars that together form a train. The locomotive power required to get a train from one point to another depends on various sources of resistance that need to be overcome. These resistances include the length of the train, drag from bearing friction, rail/wheel deflection, head wind, terrain, etc. 
     Continuous sources of drag can prevent the operation of a train at a desired speed. Additionally, propelling a train up steep grades or on slippery rail can exceed a single locomotive&#39;s power or the amount of tractive effort it can supply. A trailing locomotives may be connected to what could be considered the “lead” locomotive to provide the additional horse power or torque to push or pull a train. 
     A “locomotive consist” is a group of two or more locomotives. The locomotive consist as indicated earlier includes a lead locomotive and one or more trailing locomotives that are mechanically coupled and could be electrically coupled. 
     The mechanical coupling could be accomplished with a “coupler” and the electrical connection could be accomplished using the 27-pin control plug, cable and receptacle. The power and braking systems could use this control plug, cable and receptacle for communication so that the group of locomotives function together as a single unit. This 27-pin conductor cable is often referred to in the industry as the MU cable in that it physically connects multiple locomotives/units together. This connection could allow the lead locomotives to communicate to trailing units. The Association of American Railroads (AAR) specifies which functions are assigned to which pins. MU cables have been used since the 1930s to link the control systems which originally primarily consisted of relays and analog circuitry, typically communicating a simple ON/OFF state. 
     With advances in technology and computing devices, this basic link is no longer adequate. The ability to communicate more information, bi-directionally, and at a faster rate allows for the implementation of new processes and applications such as fuel management, advanced diagnostics, redundancy of components at a consist level, etc. 
     There are a number of ways to create an intra-consist network. Communication may be accomplished by adding high-speed network cables to the locomotives, or wirelessly. A wireless connection has various advantages, including retrofitting relatively easily existing locomotives, and providing a communication means between locomotives that are part of the consist but that are not electrically connected using the MU cable. 
     As of yet, establishing a communication network between units of a locomotive consist required the intervention of an operator. The operator would manually configure computers in each of the units by supplying each computer with the data required to connect to the network, including a password, a key code, and/or various parameters required for network communication. This process is time consuming, inefficient and prone to human errors. 
     The networked inter-locomotive communication systems in the prior art require considerable user intervention for setting up a network, and they are unable to automatically restore themselves in the event of an interruption. 
     There is a need for an intra-consist networked communication systems and methods that overcomes the above-mentioned shortcomings. 
     SUMMARY 
     One aspect of the present disclosure provides a method of automatically setting up a wireless communication network in a locomotive consist. The method includes transmitting from a leading locomotive a ping to a first trailing locomotive through a first MU cable, receiving from the first trailing locomotive a reply ping through the first MU cable, and transmitting wireless network setup information through the first MU cable from the leading locomotive to the first trailing locomotive. 
     Another aspect of the present disclosure provides a communication control system for automatically setting up a wireless communication network in a locomotive consist. The system includes a first controller in a leading unit, a second controller in a trailing unit, and an MU cable connecting the leading unit with the trailing unit, wherein the first controller is adapted to communicate to the second controller a ping through the MU cable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of locomotive consist equipped with an automatically synchronizing wireless communication system, according to an embodiment of the present invention. 
         FIG. 2  is a block diagram of locomotive controller, according to an embodiment of the present invention. 
         FIG. 3  is a flow chart of a procedure for automatically synchronizing the wireless communication of a leading locomotive, according to an embodiment of the present invention. 
         FIG. 4  is a flow chart of a procedure for automatically synchronizing the wireless communication of a trailing locomotive, according to an embodiment of the present invention. 
         FIG. 5  is a flow chart of a procedure for manually synchronizing wireless communication of a trailing unit, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a diagram of locomotive consist equipped with an automatically synchronizing wireless communication system, according to an embodiment of the present invention. Locomotive consist  1  includes a group of two or more locomotives  2 ,  3  and  4  linked together to travel along a rail. Locomotive  2  may be considered the lead unit (because this unit has the lead/trail switch set to LEAD), and locomotive  4  would then be considered a trailing unit (because this unit has the lead/trail switch set to TRAIL). The locomotives are equipped with various control system components further described below to control communication and propulsion. The multiple units are connected to each other with MU cable  8  connecting the MU receptacle  7  and MU plug  10  of locomotive  2  to the MU receptacle  5  and MU plug  11  of locomotive  3 . 
     Locomotives may need to communicate an increasing amount of data at a fast rate in order to share the data and communicate control commands throughout the consist. The data could include environmental sensory data, fuel gauge data, diagnostic data, etc. The control commands could include acceleration or deceleration commands. 
     As described in detail below, the MU cables provide a connection which allows the leading locomotive to communicate with the rest of the units in the consist. This communication could be used to setup a high-speed wireless network of communication to share data throughout the consist and issue commands from the leading locomotive to any of the locomotives connected to the network. 
     For example, a leading locomotive may communicate with the last trailing locomotive to coordinate acceleration and deceleration. In the event that a sensor malfunctions in locomotive  2 , the identical sensor in locomotive  3  or locomotive  4  may communicate the sensor information through the data network to locomotive  2 . This redundancy ensures the continued operation of the consist regardless of the occasional failure of certain sensors. The data network between locomotives may use packet switching for transmitting the data throughout the network. Locomotives may be identified using an Internet Protocol (IP) address. 
     The data exchanged between locomotives may be encrypted for security purposes. For example, event recorder data may be encrypted and exchanged between locomotives and saved on multiple locomotives. An encryption module may be integrated within a control unit, or may be separate from the control unit. 
     In an embodiment of the present disclosure, a wireless network is formed to share data throughout the consist. The leading locomotive  2  can transmit data through the MU cables throughout the consist to provide each locomotive with the necessary information to automatically connect to a wireless network established by the lead unit without the intervention of an operator. As described in detail below with respect to  FIGS. 3 and 4 , this process takes place automatically as soon as an MU cable is connected between the leading locomotive and any number of trailing units in the consist. 
       FIG. 2  is an exemplary block diagram of a locomotive controller, according to an embodiment of the present invention. Controller  28  contains various modules to control acceleration and deceleration, manage sensory data and wireless communication, among other tasks. 
     The control module  20  receives data and/or instructions through the MU cable communication unit  22 . The control module  20  may also receive an input from input interface  21 , which may include a keyboard, a touch screen, a computer, a pad, a mobile device, a panel of relays and/or switches, etc. Control module  20  may include a processor, a hard disk, a static or dynamic memory, a parallel to serial data stream converter, and software and/or firmware code. 
     Control module  20  communicates acceleration/deceleration commands to the powertrain control unit  25  through the motor control unit  23  and the brake control unit  24 . Control module  20  also communicates with GPS module  26  in order to obtain global positioning data relating to the location of the MU. Wireless communication control unit  27  manages the wireless transmission of data. Wireless communication control unit  27  may use any type of wireless communication, including WIFI (IEEE 802.11), UWB (IEEE 802.15.3a), 3G, 4G LTE, etc. along with any of the various security protocols such as WPA, WPA2, WPS, etc. For example, the global positioning (GPS) data may be communicated to the leading unit or to the home office via a cellular transmitter integrated in the wireless communication control unit  27 . Another example, the data relating to sensory information may be communicated between locomotives using a commercial long-range WIFI transmitter. 
     INDUSTRIAL APPLICABILITY 
       FIG. 3  is a flow chart of a procedure for automatically synchronizing the wireless communication of a leading locomotive, according to an embodiment of the present invention. When the status of a locomotive is switched from “TRAIL” to “LEAD” or the locomotive control system powers up with a “LEAD” setting (step  31 ) the locomotive may disconnect itself from any network it is connect to (step  32 ) and stop the transmission of any heartbeats (step  33 ). A heartbeat may be a form of a ping, as commonly known in the computer networking industry. 
     A ping may operate by sending Internet Control Message Protocol (ICMP) echo request packets to a target host (including any locomotive in the consist) and waiting for an ICMP response. In the process it may measure the time from transmission to reception (round-trip time) and may record any packet loss. The results of the test may be used as statistical summary of the response packets received, including the minimum, maximum, and the mean round-trip times, and sometimes the standard deviation of the mean. 
     Depending on the implementation, the ping command can be run with various command line switches to enable special operational modes. Example options include: specifying the packet size used as the probe, automatic repeated operation for sending a specified count of probes, and time stamping. 
     In step  34  of  FIG. 3 , the leading locomotive may create a new wireless network and broadcast the lead heartbeat/ping/message (step  35 ). In step  36 , the leading locomotive may continuously listen for a reply heartbeat/ping/reply. When the leading locomotive receives a reply it may send network setup information to the remote unit that replied (step  38 ). Once the remote unit is connected to the wireless network, it may continuously transmit a heartbeat/ping to the leading locomotive. The remote unit may remain connected to the wireless network as long as its heartbeat is received by the leading locomotive. If the leading locomotive no longer receives the heartbeat of the remote unit, then the remote unit is disconnected from the network and the process may restart from step  35 . 
       FIG. 4  is a flow chart of a procedure for automatically synchronizing the wireless communication of a trailing locomotive, according to an embodiment of the present invention. When the status of a locomotive is switched from “LEAD” to “TRAIL” or the locomotive control system powers up with a “TRAIL” setting (step  41 ) the locomotive may disconnect itself from any network it is connect to (step  42 ) and stop the transmission of any heartbeats/pings (step  43 ). As discussed above, a heartbeat may be a form of a ping, as commonly known in the computer networking industry. The trailing locomotive may continuously attempt to detect the heartbeat/ping of the leading locomotive. When the leading heartbeat/ping is detected then the trailing locomotive may reply to the lead unit and connect to the wireless network using the wireless network setup data transmitted to it by the leading locomotive via the MU cable. Once connected to the network, the trailing locomotive may continuously transmit wirelessly its heartbeat to the leading locomotive. If the leading locomotive does not detect the heartbeat/ping of the trailing locomotive, then the trailing locomotive may be disconnected from the network and the process may restart at step  44 . 
       FIG. 5  is a flow chart of a procedure for manually synchronizing wireless communication of a trailing unit, according to an embodiment of the present invention. When a trailing unit is unable to receive the leading ping through the MU cable, the wireless network may be setup manually using Input Interface  21 ) shown in  FIG. 2 . The trailing unit may accept input from a Graphical User Interface (GUI) (step  51 ) in order to setup the network for communication (step  52 ) or to disconnect the trailing unit from the wireless network (step  58 ). Then, the trailing unit may continuously transmit wirelessly a ping to the lead (step  53 ) and continuously detect the wireless ping of the leading locomotive (step  54 ). If either (i) the wireless ping of the leading locomotive is not detected by the trailing locomotive, or (ii) the wireless ping of the trailing locomotive is not detected by the leading locomotive, then after a delay (step  57 ) the trailing locomotive will be disconnected from the network (step  58 )and the process may be restarted at step  51 . If, after periodic checks (step  56 ), (i) the wireless ping of the leading locomotive is detected by the trailing locomotive, and (ii) the wireless ping of the trailing locomotive is detected by the leading locomotive, then the trailing unit may stay connected to the wireless network.