Patent Publication Number: US-8538608-B2

Title: Control system and method for remotely isolating powered units in a rail vehicle system

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to powered rail vehicle systems. 
     Known powered rail vehicle systems include one or more powered units and, in certain cases, one or more non-powered rail cars. The powered units supply tractive force to propel the powered units and cars. The non-powered cars hold or store goods and/or passengers. (“Non-powered” rail car generally encompasses any rail car without an on-board source of motive power.) For example, some known powered rail vehicle systems include a rail vehicle system (e.g., train) having locomotives and cars for conveying goods and/or passengers along a track. Some known powered rail vehicle systems include several powered units. For example, the systems may include a lead powered unit, such as a lead locomotive, and one or more remote or trailing powered units, such as trailing locomotives, that are located behind and (directly or indirectly) coupled with the lead powered unit. The lead and remote powered units supply tractive force to propel the vehicle system along the track. 
     The tractive force required to convey the powered units and cars along the track may vary during a trip. For example, due to various parameters that change during a trip, the tractive force that is necessary to move the powered units and the cars along the track may vary. These changing parameters may include the curvature and/or grade of the track, speed limits and/or requirements of the system, and the like. As these parameters change during a trip, the total tractive effort, or force, that is required to propel the vehicle system along the track also changes. 
     While the required tractive effort may change during a trip, the operators of these powered rail vehicle systems do not have the ability to remotely turn the electrical power systems of remote powered units on or off during the trip. For example, an operator in a lead locomotive does not have the ability to remotely turn one or more of the trailing locomotives&#39; electrical power on or off, if the tractive effort required to propel the train changes during a segment of the trip while the rail vehicle system is moving. Instead, the operator may only have the ability to locally turn on or off the remote powered units by manually boarding each such unit of the rail vehicle system. 
     Some known powered rail vehicle systems provide an operator in a lead locomotive with the ability to change the throttle of trailing locomotives (referred to as distributed power operations). But, these known systems do not provide the operator with the ability to turn the trailing locomotives off. Instead, the operator must turn down the throttle of the trailing locomotives that he or she wants to turn off and wait for an auto engine start/stop (AESS) device in the trailing locomotives to turn the locomotives off. Some known AESS devices do not turn the trailing locomotives off until one or more engine- or motor-related parameters are within a predetermined range. For example, some known AESS devices may not shut off the engine of a trailing locomotive until the temperature of the engine decreases to a predetermined threshold. If the time period between the operator turning down the throttle of the trailing locomotives and the temperature of the engines decreasing to the predetermined threshold is significant, then the amount of fuel that is unnecessarily consumed by the trailing locomotives can be significant. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, a control system for a rail vehicle system including a lead powered unit and a remote powered unit is provided. The system includes a user interface, a master isolation module, and a slave controller. The user interface is disposed in the lead powered unit and is configured to receive an isolation command to turn on or off the remote powered unit. The master isolation module is configured to receive the isolation command from the user interface and to communicate an instruction based on the isolation command. The slave controller is configured to receive the instruction from the master isolation module. The slave controller causes the remote powered unit to supply tractive force to propel the rail vehicle system when the instruction directs the slave controller to turn on the remote powered unit. The slave controller causes the remote powered unit to withhold the tractive force when the instruction directs the slave controller to turn off the remote powered unit. 
     In another embodiment, a method for controlling a rail vehicle system that includes a lead powered unit and a remote powered unit is provided. The method includes providing a user interface in the lead powered unit to receive an isolation command to turn on or off the remote powered unit and a slave controller in the remote powered unit. The method also includes communicating an instruction based on the isolation command to the slave controller and directing the slave controller to cause the remote powered unit to supply tractive force to propel the rail vehicle system when the instruction directs the slave controller to turn on the remote powered unit and to cause the remote powered unit to withhold the tractive force when the instruction directs the slave controller to turn off the remote powered unit. 
     In another embodiment, a computer readable storage medium for a control system of a rail vehicle system is having a lead powered unit and a remote powered unit is provided. The lead powered unit includes a microprocessor and the remote powered unit includes a slave isolation module and a slave controller. The computer readable storage medium includes instructions to direct the microprocessor to receive an isolation command to turn on or off the remote powered unit. The instructions also direct the microprocessor to communicate an instruction based on the isolation command. The slave controller receives the instruction to cause the remote powered unit to supply tractive force to propel the rail vehicle system when the instruction directs the slave controller to turn on the remote powered unit and to withhold the tractive force when the instruction directs the slave controller to turn off the remote powered unit. 
     In another embodiment, a method for controlling a train having a lead locomotive and a remote locomotive is provided. The method includes communicating an instruction that relates to an operational state of the remote locomotive from the lead locomotive to the remote locomotive. The method also includes controlling an engine of the remote locomotive at the remote locomotive based on the instruction into one of an on operational state and an off operational state. The engine does not combust fuel during at least a portion of a time period when the engine is in the off operational state. 
     As should be appreciated, the control system, method, and computer readable storage medium remotely adjust the tractive force provided by powered units in a powered rail vehicle system by turning powered units in the system on or off. Such a system, method, and computer readable storage medium can improve some known rail vehicle systems by reducing the amount of fuel that is consumed during a trip. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration of a rail vehicle system that incorporates an isolation control system constructed in accordance with one embodiment. 
         FIG. 2  is a schematic illustration of an isolation control system in accordance with one embodiment. 
         FIG. 3  is a schematic diagram of an isolation control system in accordance with another embodiment. 
         FIG. 4  is a flowchart for a method of controlling a rail vehicle system that includes a lead powered unit and a remote powered unit in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. To the extent that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry. Thus, for example, one or more of the functional blocks (for example, processors or memories) may be implemented in a single piece of hardware (for example, a general purpose signal processor, microcontroller, random access memory, hard disk, and the like). Similarly, the programs may be stand alone programs, may be incorporated as subroutines in an operating system, may be functions in an installed software package, and the like. The various embodiments are not limited to the arrangements and instrumentality shown in the drawings. 
     As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. 
     It should be noted that although one or more embodiments may be described in connection with powered rail vehicle systems, the embodiments described herein are not limited to trains. In particular, one or more embodiments may be implemented in connection with different types of rail vehicles (e.g., a vehicle that travels on one or more rails, such as single locomotives and railcars, powered ore carts and other mining vehicles, light rail transit vehicles, and the like) and other vehicles. Example embodiments of systems and methods for remotely isolating remote powered units in a rail vehicle system are provided. At least one technical effect described herein includes a method and system that permits an operator in a lead powered unit to remotely turn a remote powered unit on or off. 
       FIG. 1  is a schematic illustration of a rail vehicle system  100  that incorporates an isolation control system constructed in accordance with one embodiment. The rail vehicle system  100  includes a lead powered unit  102  coupled with several remote powered units  104 ,  106 ,  108 ,  110  and individual rail cars  112 . The rail vehicle system  100  travels along a track  114 . The lead powered unit  102  and the remote powered units  104 - 110  supply a tractive force to propel the rail vehicle system  100  along the track  114 . In one embodiment, the lead powered unit  102  is a leading locomotive disposed at the front end of the rail vehicle system  100  and the remote powered units  104 - 110  are trailing locomotives disposed behind the lead powered unit  102  between the lead powered unit  102  and the back end of the rail vehicle system  100 . The individual rail cars  112  may be non-powered storage units for carrying goods and/or passengers along the track  114 . 
     The remote powered units  104 - 110  are remote from the lead powered unit  102  in that the remote powered units  104 - 110  are not located within the lead powered unit  102 . A remote powered unit  104 - 110  need not be separated from the lead powered unit  102  by a significant distance in order for the remote powered unit  104 - 110  to be remote from the lead powered unit  102 . For example, the remote powered unit  104  may be directly adjacent to and coupled with the lead powered unit  102  and still be remote from the lead powered unit  102 . In one embodiment, the lead powered unit  102  is not located at the front end of the rail vehicle system  100 . For example, the lead powered unit  102  may trail one or more individual cars  112  and/or remote powered units  104 - 110  in the rail vehicle system. Thus, unless otherwise specified, the terms “lead,” “remote,” and “trailing” are meant to distinguish one rail vehicle from another, and do not require that the lead powered unit be the first powered unit or other rail vehicle in a train or other rail vehicle system, or that the remote powered units be located far away from the lead powered unit or other particular units, or that a “trailing” unit be behind the lead unit or another unit. The number of powered units  102 - 110  in the rail vehicle system  100  may vary from those shown in  FIG. 1 . 
     The remote powered units  104 - 110  may be organized into groups. In the illustrated embodiment, the remote powered units  104 ,  106  are organized into a consist group  116 . A consist group  116  may include one or more powered units  102 - 110  that are the same or similar models and/or are the same or similar type of powered unit. For example, a consist group  116  may include remote powered units  104 ,  106  that are manufactured by the same entity, supply the same or similar tractive force, have the same or similar braking capacity, have the same or similar types of brakes, and the like. The powered units  102 - 104  in a consist group  116  may be directly coupled with one another or may be separated from one another but interconnected by one or more other components or units. 
     The remote powered units  108 ,  110  are organized into a distributed power group  118  in the illustrated embodiment. Similar to a consist group  116 , a distributed power group  118  may include one or more powered units  102 - 110 . The powered units  102 - 110  in a distributed power group  118  may be separated from one another but interconnected with one another by one or more other powered units  102 - 110  and/or individual cars  112 . 
     In operation, the lead powered unit  102  remotely controls which of the remote powered units  104 - 110  are turned on and which remote powered units  104 - 110  are turned off. For example, an operator in the lead powered unit  102  may remotely turn one or more of the remote powered units  104 - 110  on or off while remaining in the lead powered unit  102 . The lead powered unit  102  may remotely turn on or off individual remote powered units  104 - 110  or entire groups of remote powered units  104 - 110 , such as the remote powered units  104 ,  106  in the consist group  104 - 106  and/or the remote powered units  108 ,  110  in the distributed power group  116 . The lead powered unit  102  remotely turns the remote powered units  104 - 110  on or off when the rail vehicle system  100  is moving along the track  114  and/or when the rail vehicle system  110  is stationary on the track  114 . 
     The remote powered units  104 - 110  supply tractive forces to propel the rail vehicle system  100  along the track  114  when the respective remote powered units  104 - 110  are turned on. Conversely, the individual remote powered units  104 - 110  withhold tractive forces and do not supply a tractive force to propel the rail vehicle system  100  along the track  114  when the respective remote powered units  104 - 110  are turned off. The lead powered unit  102  may control which of the remote powered units  104 - 110  are turned on and which of the remote powered units  104 - 110  are turned off based on a variety of factors. By way of example only, the lead powered unit  102  may turn off some remote powered units  104 - 110  while leaving other remote powered units  104 - 110  on if the remote powered units  104 - 110  that remain on are supplying sufficient tractive force to propel the rail vehicle system  100  along the track  114 . 
     The lead powered unit  102  communicates with the remote powered units  104 - 110  in order to turn the remote powered units  104 - 110  on or off. The lead powered unit  102  may communicate instructions to the remote powered units  104 - 110  via a wired connection  120  and/or a wireless connection  122  between the lead powered unit  102  and the remote powered units  104 - 110 . By way of non-limiting example only, the wired connection  120  may be a wire or group of wires, such as a trainline or MU cables, that extends through the powered units  102 - 110  and cars  112  of the rail vehicle system  100 . The wireless connection  122  may include radio frequency (RF) communication of instructions between the lead powered unit  102  and one or more of the remote powered units  104 - 110 . 
       FIG. 2  is a schematic illustration of the isolation control system  200  in accordance with one embodiment. The isolation control system  200  enables an operator in the lead powered unit  102  (shown in  FIG. 1 ) to remotely change a powered or operational state of one or more of the remote powered units  104 - 110  (shown in  FIG. 1 ). The powered or operational state of one or more of the remote powered units  104 - 110  may be an “on” operational state or an “off” operational state based on whether power is supplied to (or by) engines  228 - 232  of the remote powered units  104 - 110 . For example, a remote powered unit  104  may be turned to an “off” state by shutting off power to the engine  228  in the remote powered unit  104 . Depending on the type of engine involved, this may include one or more of the following: communicating with an engine controller or control system that the engine is to be turned off; shutting off a supply of electricity to the engine, where the electricity is required by the engine to operate (e.g., spark plug operation, fuel pump operation, electronic injection pump); shutting off a supply of fuel to the engine; shutting off a supply of ambient air or other intake air to the engine; restricting the output of engine exhaust; or the like. Turning the engine  228 - 232  of a remote powered unit  104 - 110  off may prevent the engine  228 - 232  in the remote powered unit  104 - 110  from generating electricity. (As should be appreciated, this assumes that the engine output is connected to a generator or alternator, as is common in a locomotive or other powered unit; thus, unless otherwise specified, the term “engine” refers to an engine system including an engine and alternator/generator.) If the engine  228 - 232  is turned off and does not generate electricity, then the engine  228 - 232  cannot generate electricity that is fed to one or more corresponding electric motors  234 - 238  in the remote power units  104 - 110 , and the motors  234 - 238  may be unable to move the axles and wheels of the remote powered unit  104 - 110 . (In this configuration, common among locomotives and other rail powered units, electric motors are connected to the vehicle axles, via a gear set, for moving the powered unit, while the engine is provided for generating electricity for electrically powering the motors.) In one embodiment, a remote powered unit  104 - 110  is turned “off” by directing the engine  228 - 232  in the remote powered unit  104 - 110  to cease or stop supplying tractive effort. For example, the remote powered unit  104 - 110  may be turned off by directing the engine  228 - 232  of the remote powered unit  104 - 110  to stop supplying electricity to the corresponding motor(s)  234 - 238  of the remote powered unit  104 - 110  that provide tractive effort for the remote powered unit  104 - 110 . 
     In another embodiment, a remote powered unit  104 - 110  (shown in  FIG. 1 ) may be turned off by completely shutting down the corresponding engine  228 - 232  of the remote powered unit  104 - 110 . For example, the engine  228 - 232  may be shut down such that the engine  228 - 232  is no longer combusting, burning, or otherwise consuming fuel to generate electricity. A remote powered unit  104 - 110  may be changed to an “off” state by temporarily shutting down the engine  228 - 232  such that the engine  228 - 232  is no longer combusting, burning, or otherwise consuming fuel to generate electricity but for periodic or non-periodic and relatively short time periods where the engine  228 - 232  is changed to an “on” state in order to maintain a designated or predetermined engine temperature. The power that is supplied to the engine  228 - 232  during the short time periods may be sufficient to cause the engine  228 - 232  to combust some fuel while being insufficient to enable the engine  228 - 232  to provide tractive effort to the corresponding remote powered unit  104 - 110 . 
     In one embodiment, the state of an engine  228 - 232  of a remote powered unit  104 - 110  (shown in  FIG. 1 ) is changed to an “off” state when the power that is supplied by the engine  228 - 232  is reduced below a threshold at which an Automatic Engine Start/Stop (AESS) system assumes control of the powered or operating state of the engine  228 - 232 . For example, the engine  228  of the remote powered unit  104  may be shut off by decreasing the power supplied by the engine  228  to the motor  234  until the supplied power falls below a predetermined threshold at which the AESS system takes over control of the engine  228  and determines when to turn the engine  228  completely off. Alternatively, the engines  228 - 232  of the remote powered units  104 - 110  may be individually turned on or off independent of an AESS system. For example, the engine  228 - 232  of a remote powered unit  110  may be turned on or off regardless of whether the engine  228 - 232  is susceptible to control by an AESS system. 
     The isolation control system  200  may remotely change the powered state of the engine(s) of one or more of the remote powered units  104 - 110  (shown in  FIG. 1 ) in accordance with one or more of the embodiments described above. The isolation control system  200  includes a master isolation unit  202  and several slave controllers  204 ,  206 ,  208 . In one embodiment, the master isolation unit  202  is disposed in the lead powered unit  102 . Alternatively, only a part or subsection of the master isolation unit  202  is disposed in the lead powered unit  102 . For example, a user interface  210  of the master isolation unit  202  may be located in the lead powered unit  102  while one or more other components of the master isolation unit  202  are disposed outside of the lead powered unit  102 . The slave controllers  204 - 208  are disposed in one or more of the remote powered units  104 - 110 . For example, the slave controller  204  may be located within the remote powered unit  104 , the slave controller  206  may be disposed in the remote powered unit  106 , and the slave controller  208  may be located at the remote powered unit  108 . The number of slave controllers  204 - 208  in the isolation control system  200  may be different from the embodiment shown in  FIG. 2 . Similar to the master isolation unit  202 , one or more components or parts of the slave controllers  204 - 208  may be disposed outside of the corresponding remote powered units  104 - 110 . The master isolation unit  202  and/or slave controllers  204 - 208  may be embodied in one or more wired circuits with discrete logic components, microprocessor-based computing systems, and the like. As described below, the master isolation unit  202  and/or the slave controllers  204 - 208  may include microprocessors that enable the lead powered unit  102  (shown in  FIG. 1 ) to remotely turn the remote powered units  104 - 110  on or off. For example, one or more microprocessors in the master isolation unit  202  and/or slave controllers  204 - 208  may generate and communicate signals between the master isolation unit and the slave controllers  204 - 208  that direct one or more of the corresponding engines  228 - 232  of the remote powered units  104 - 110  to change the powered state of the engines  228 - 232  from an “on” state to an “off” state, as described above. 
     The master isolation unit  202  includes the user interface  210  that accepts input from an operator of the master isolation unit  202 . For example, the user interface  210  may accept commands or directions from an engineer or other operator of the lead powered unit  102  (shown in  FIG. 1 ). By way of non-limiting example only, the user interface  210  may be any one or more of a rotary switch, a toggle switch, a touch sensitive display screen, a keyboard, a pushbutton, a software application or module running on a processor-based computing device, and the like. The operator inputs an isolation command  212  into the user interface  210 . The isolation command  212  represents a request by the operator to turn one or more of the remote powered units  104 - 110  on and/or to turn one or more of the remote powered units  104 - 110  off. The user interface  210  communicates the operator&#39;s request to a master isolation module  214 . 
     The master isolation module  214  receives the operator&#39;s request from the user interface  210  and determines which ones of the remote powered units  104 - 110  (shown in  FIG. 1 ) are to be turned on and/or which ones of the remote powered units  104 - 110  are to be turned off. For example, the isolation command  212  may request that a single remote powered unit  106  be turned off or on. Alternatively, the isolation command  212  may request that a group of the remote powered units  104 - 110  be turned on or off. For example, the isolation command  212  may select the remote powered units  104 - 110  in a selected consist group  116  and/or a distributed power group  118  (shown in  FIG. 1 ) be turned off or on. By way of non-limiting example only, the master isolation module  214  may be embodied in any one or more of hardwired circuitry, rotary, or other types, of switches, a microprocessor based device, a software application or module running on a computing device, a discrete logic device, and the like. Based on the operator&#39;s request communicated via the isolation command  212 , the master isolation module  214  conveys an isolation instruction  216  to a master input/output (I/O) device  218 . 
     The master I/O device  218  is a device that communicates the isolation instruction  216  to the remote powered units  104 - 110  (shown in  FIG. 1 ) selected by the master isolation module  214 . For example, if the isolation command  212  from the operator requests that one or more individual remote powered units  104 - 110  be turned off or on, or that the remote powered units  104 - 110  in a selected consist or distributed power group  116 ,  118  be turned off or on, the master I/O device  218  communicates the isolation instruction  216  to at least those remote powered units  104 - 110  selected by the isolation command  212 . By way of non-limiting example only, the master I/O device  218  may be embodied in one or more of a connector port that is electronically coupled with one or more wires joined with the remote powered units  104 - 110  (such as a trainline), an RF transmitter, a wireless transceiver, and the like. In one embodiment, the master I/O device  218  conveys the isolation instruction  216  to all of the remote powered units  104 - 110  in the rail vehicle system  100  (shown in  FIG. 1 ). While the illustrated embodiment shows the isolation instruction  216  being communicated in parallel to the slave controllers  204 - 208 , the isolation instruction  216  may be serially communicated among the slave controllers  204 - 208 . For example, the master I/O device  218  may serially convey the isolation instruction  216  to the remote powered units  104 - 110  along a trainline. The remote powered units  104 - 110  that are to be turned on or off by the isolation instruction  216  receive the isolation instruction  216  and act on the isolation instruction  216 . The remote powered units  104 - 110  that are not to be turned on or off by the isolation instruction  216  ignore the isolation instruction  216 . For example, the remote powered units  104 - 110  may include discrete logic components that are coupled with a trainline and that receive the isolation instruction  216  when the isolation instruction  216  relates to the remote powered units  104 - 110  and ignores the isolation instruction  216  when the isolation instruction  216  does not relate to the remote powered units  104 - 110 . 
     In another embodiment, the master I/O device  218  broadcasts the isolation instruction  216  to all of the remote powered units  104 - 110  (shown in  FIG. 1 ) in the rail vehicle system  100  (shown in  FIG. 1 ). For example, the master I/O device  218  may include a wireless transceiver that transmits data packets comprising the isolation instruction  216  to the remote powered units  104 - 110 . Alternatively, the master I/O device  218  may be an RF transmitter that transits a radio frequency signal that includes the isolation instruction  216 . The remote powered units  104 - 110  may be associated with unique identifiers, such as serial numbers, that distinguish the remote powered units  104 - 110  from one another. The isolation instruction  216  may include or be associated with one or more of the unique identifiers to determine which of the remote powered units  104 - 110  are to receive and act on the isolation instruction  216 . For example, if the unique identifier of a remote powered unit  104 - 110  matches an identifier stored in a header of a data packet of the isolation instruction  216  or communicated in the RF signal, then the remote powered unit  104 - 110  having the mating unique identifier receives and acts on the isolation instruction  216 . 
     A slave input/output (I/O) device  220  receives the isolation instruction  216  from the master I/O device  218 . By way of non-limiting example only, the slave I/O devices  220  may be embodied in one or more of a connector port that is electronically coupled with one or more wires joined with the lead powered unit  102  (such as a trainline), an RF transmitter, a wireless transceiver, and the like. The slave I/O devices  220  convey the isolation instruction  216  to a slave isolation module  222 . 
     The slave isolation module  222  receives the isolation instruction  216  from the slave I/O device  220  and determines if the corresponding remote powered unit  104 - 110  (shown in  FIG. 1 ) is to be turned on or off in response to the isolation instruction  216 . The slave isolation module  222  may include logic components to enable the slave isolation module  222  to determine whether the associated remote powered unit  104 - 110  (shown in  FIG. 1 ) is to obey or ignore the isolation instruction  216 . For example, the slave isolation modules  222  may include one or more of hardwired circuitry, relay switches, a microprocessor based device, a software application or module running on a computing device, and the like, to determine if the associated remote powered unit  104 - 110  is to act on the isolation instruction  216 . 
     If the slave isolation module  222  determines that the corresponding remote powered unit  104 - 110  (shown in  FIG. 1 ) is to be turned on or off in response to the isolation instruction  216 , then the slave isolation module  222  communicates an appropriate command  224  to an engine interface device  226 . The engine interface device  226  receives the command  224  from the slave isolation module  222  and, based on the command  224 , directs the engine  228 ,  230 ,  232  of the corresponding remote powered unit  104 - 110  to turn on or off. For example, the engine interface device  226  associated with the remote powered unit  104  may communicate the command  224  to the engine  228  of the remote powered unit  104 . By way of non-limiting example only, the engine interfaces  226  may be embodied in one or more of a connector port that is electronically coupled with the engines  228 - 232  via one or more wires. Upon receiving the command  224  from the engine interfaces  226 , the engines  228 - 232  may change operational states from “on” to “off,” or from “off” to “on.” As described above, in one embodiment, the engines  228 - 232  may turn off and cease supplying electricity to a corresponding motor  234 - 238  in order to cause the motor  234 - 238  to supply or withhold application of tractive force. For example, if the engine  230  receives a command  224  directing the engine  230  to turn off and the engine  232  receives a command  224  directing the engine  232  to turn on, then the engine  230  shuts down and stops providing electricity to the motor  236 , which in turn stops providing a tractive force to propel the rail vehicle system  100  (shown in  FIG. 1 ), while the engine  232  turns on and begins supplying electricity to the motor  238  to cause the motor  238  to provide a tractive force to propel the rail vehicle system  100 . 
     In one embodiment, the engine  228 - 232  turns on or off within a predetermined time period. For example, an engine  228  that is used to supply tractive effort may shut off within a predetermined time period after the slave isolation module  222  receives the isolation instruction  216 . The predetermined time period may be established or set by an operator of the system  200 . The turning on or off of the engine  228 - 232  within a predetermined time period after the slave isolation module  222  receives the isolation instruction  216  may permit an operator in the lead powered unit  102  (shown in  FIG. 1 ) to send the isolation instruction  216  to the remote powered units  104 - 110  (shown in  FIG. 1 ) to turn off the engines  228 - 232  immediately, or at least relatively soon after the isolation command  212  is input into the user interface  210 . For example, the slave isolation modules  222  may turn off the engines  228 - 232  without waiting for the engines  228 - 232  to cool down to a threshold temperature. 
     The master isolation unit  202  may convey additional isolation instructions  216  to the slave controllers  204 - 208  during a trip. A trip includes a predetermined route between two or more waypoints or geographic locations over which the rail vehicle system  100  (shown in  FIG. 1 ) moves. For example, an operator in the lead powered unit  102  (shown in  FIG. 1 ) may periodically input isolation commands  212  into the master isolation unit  202  to vary the total amount of tractive force supplied by the powered units  102 - 110  (shown in  FIG. 1 ). The operator may vary the number and/or type of powered units  102 - 110  being used to supply tractive force to propel the rail vehicle system  100  during the trip in order to account for various static or dynamically changing factors and parameters, such as, but not limited to, a speed limit of the rail vehicle system  100 , a changing grade and/or curvature of the track  114  (shown in  FIG. 1 ), the weight of the rail vehicle system  100 , a distance of the trip, a distance of a segment or subset of the trip, a performance capability of one or more of the powered units  102 - 110 , a predetermined speed of the rail vehicle system  100 , and the like. 
       FIG. 3  is a schematic diagram of an isolation control system  300  in accordance with another embodiment. The control system  300  may be similar to the control system  200  (shown in  FIG. 2 ). For example, the control system  300  may be used to remotely turn one or more remote powered units  104 - 110  (shown in  FIG. 1 ) on or off from the lead powered unit  102  (shown in  FIG. 1 ). The control system  300  is a microprocessor-based control system. For example, the control system  300  includes one or more microprocessors  308 ,  320  that permit an operator to manually turn one or more of the remote powered units  104 - 110  on or off. Additionally, the control system  300  may be utilized to automatically turn one or more of the remote powered units  104 - 110  on or off. 
     The control system  300  includes a master isolation unit  302  and a slave controller  304 . The master isolation unit  302  may be similar to the master isolation unit  202  (shown in  FIG. 2 ). For example, the master isolation unit  302  includes a master isolation module  314 , a user interface  310 , and a master I/O device  318 . The user interface  310  may be the same as, or similar to, the user interface  210  (shown in  FIG. 2 ) and the master I/O device  318  may be the same as, or similar to, the master I/O device  218  (shown in  FIG. 2 ). The master isolation module  314  includes a memory  306  and a microprocessor  308 . The memory  306  represents a computer readable storage device or medium. The memory  306  may include sets of instructions that are used by the microprocessor  308  to carry out one or more operations. By way of example only, the memory  306  may be embodied in one or more of an electrically erasable programmable read only memory (EEPROM), a read only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), or FLASH memory. The microprocessor  308  represents a processor, microcontroller, computer, or other electronic computing or control device that is configured to execute executing instructions stored on the memory  306 . (Thus, unless otherwise specified, the term “microprocessor” includes any of the aforementioned devices.) 
     The slave controller  304  may be similar to one or more of the slave controllers  204 - 208  (shown in  FIG. 2 ). For example, the slave controller  304  includes a slave isolation module  322 , an engine interface  326 , and a slave I/O device  320 . The engine interface  326  may be the same as, or similar to, the engine interface  226  (shown in  FIG. 2 ) and the slave I/O device  320  may be the same as, or similar to, the slave I/O device  220  (shown in  FIG. 2 ). The slave isolation module  322  may include a memory  312  and a microprocessor  316 . Alternatively, one or more of the slave controllers  304  in the remote powered units  104 - 110  (shown in  FIG. 1 ) does not include memories  312  and/or microprocessors  316 . The memory  312  may be the same as, or similar to, the memory  306  in the master isolation module  314  and the microprocessor  316  may be the same as, or similar to, the microprocessor  308  in the master isolation module  314 . 
     In operation, the master isolation unit  302  remotely turns the engines  228 - 232  (shown in  FIG. 2 ) on or off in a manner similar to the master isolation unit  202  (shown in  FIG. 2 ). The user interface  310  receives the isolation command  212  and communicates the isolation command  212  to the microprocessor  308  of the master isolation module  314 . The master isolation module  314  receives the isolation command  212  and determines which remote powered units  104 - 110  (shown in  FIG. 1 ) are to be turned on or off based on the isolation command  212 . The master isolation module  314  may query the memory  306  to determine which remote powered units  104 - 110  to turn on or off. For example, if the isolation command  212  requests that the remote powered units  104 - 110  in a selected consist or distributed power group  116 ,  118  (shown in  FIG. 1 ) be turned off, the microprocessor  308  may request a list of the remote powered units  104 - 110  that are in the selected consist or distributed power group  116 ,  118 . The master isolation module  314  then sends the isolation instruction  216  to the master I/O device  318 , which conveys the isolation instruction  216  to the selected remote powered units  104 - 110 . For example, the microprocessor  308  may direct the master I/O device  318  to communicate the isolation instruction  216  only to the remote powered units  104 - 110  selected by the isolation command  212 . In another example, the microprocessor  308  may embed identifying information in the isolation command  212 . As described above, the identifying information may be compared to a unique identifier associated with each remote powered unit  104 - 110  to determine which of the remote powered units  104 - 110  are to act on the isolation instruction  216 . 
     In one embodiment, the master isolation module  314  automatically generates the isolation instruction  216  and communicates the isolation instruction  216  to one or more of the remote powered units  104 - 110  (shown in  FIG. 1 ). For example, the master isolation module  314  may determine a tractive effort needed or required to propel the rail vehicle system  100  (shown in  FIG. 1 ) along a trip or a segment of the trip. The microprocessor  308  may calculate the required tractive effort from information and data stored in the memory  306 . By way of example only, the microprocessor  308  may obtain and determine the required tractive effort based on the distance of the trip, the distance of one or more of the trip segments, the performance capabilities of one or more of the powered units  102 - 110  (shown in  FIG. 1 ), the curvature and/or grade of the track  114  (shown in  FIG. 1 ), transit times over the entire trip or a trip segment, speed limits, and the like. 
     As the rail vehicle system  100  (shown in  FIG. 1 ) moves along the track  114  (shown in  FIG. 1 ) during the trip, the microprocessor  308  of the master isolation module  314  may adaptively generate and communicate isolation instructions  216  to the slave controllers  304  of the remote powered units  104 - 110  (shown in  FIG. 1 ) to vary which of the remote powered units  104 - 110  are turned on or off. During some segments of a trip, the required tractive effort may increase. For example, if the grade of the track  114  or the speed limit increases, the microprocessor  308  may determine that additional remote powered units  104 - 110  need to be turned on to increase the total tractive force provided by the powered units  102 - 110  (shown in  FIG. 1 ). The microprocessor  308  may automatically generate an isolation instruction  216  that turns on one or more remote powered units  104 - 110  that previously were turned off. Alternatively, during other segments of a trip, the required tractive effort may decrease. For example, if the grade of the track  114  or the speed limit decreases, the microprocessor  308  may determine that fewer remote powered units  104 - 110  are needed to propel the rail vehicle system  100 . The microprocessor  308  may automatically generate an isolation instruction  216  that turns off one or more remote powered units  104 - 110  that previously were turned on. The selection of which remote powered units  104 - 110  are turned on or off may be based on the performance capabilities of the remote powered units  104 - 110 . The performance capabilities may include the tractive force provided by the various remote powered units  104 - 110 , the rate at which the remote powered units  104 - 110  burn fuel, an exhaust emission of the remote powered units  104 - 110 , an EPA Tier level of the remote powered units  104 - 110 , the horsepower to weight ratio of the remote powered units  104 - 110 , and the like. 
     The slave controllers  304  of one or more of the remote powered units  104 - 110  (shown in  FIG. 1 ) receive the isolation instruction  216  and, based on the isolation instruction  216 , turn the corresponding engines  228 - 232  (shown in  FIG. 2 ) on or off, similar to as described above. In one embodiment, the microprocessors  316  in the slave controllers  304  receive the isolation instruction  216  and determine if the isolation instruction  216  applies to the corresponding remote powered unit  104 - 110 . For example, the microprocessor  316  may compare identifying information in the isolation instruction  216  to a unique identifier stored in the memory  312  and associated with the corresponding remote powered unit  104 - 110 . If the identifying information and the unique identifier match, the microprocessor  316  generates and communicates the command  224  to the engine interface  326 . As described above, the engine interface  326  receives the command  224  and turns the associated engine  228 - 232  on or off based on the command  224 . 
     In one embodiment, the slave controller  304  of one or more of the remote powered units  104 - 110  (shown in  FIG. 1 ) provide feedback  328  to the master isolation unit  302 . Based on the feedback  328 , the master isolation unit  302  may automatically generate and communicate isolation instructions  216  to turn one or more of the remote powered units  104 - 110  on or off. Alternatively, the master isolation unit  302  may determine a recommended course of action based on the feedback  328  and report the recommended course of action to an operator. For example, the master isolation unit  302  may display several alternative courses of action on a display device that is included with or communicatively coupled with the user interface  310 . An operator may then use the user interface  310  to select which of the courses of action to take. The master isolation module  314  then generates and communicates the corresponding isolation instruction  216  based on the selected course of action. 
     The feedback  328  may include different amounts of fuel that are consumed or burned by the remote powered units  104 - 110  (shown in  FIG. 1 ). For example, the microprocessor  316  in at least one of the remote powered units  104 - 110  may calculate the various amounts of fuel that will be consumed by the powered units  102 - 110  (shown in  FIG. 1 ) of the rail vehicle system  100  (shown in  FIG. 1 ) over a time period with different combinations of the powered units  102 - 110  turned on or off. In one embodiment, a microprocessor  316  in each consist group  116  (shown in  FIG. 1 ) and/or distributed power group  118  (shown in  FIG. 1 ) calculates the amount of fuel that will be consumed by the rail vehicle system  100  with the remote powered units  104 - 110  in the corresponding consist or distributed power group  116 ,  118  turned on and the amount of fuel that will be consumed by the rail vehicle system  100  with the remote powered units  104 - 110  in the consist or distributed power group  116 ,  118  turned off. The calculated amounts of fuel are conveyed to the slave I/O device  320  and reported to the master isolation unit  302  as the feedback  328 . Based on the feedback  328 , the master isolation unit  302  determines whether to turn on or off one or more of the remote powered units  104 - 110 . For example, each consist group  116  and/or distributed power group  118  may provide feedback  328  that notifies the master isolation unit  302  of the different amounts of fuel that will be consumed if the various groups  116 ,  118  are turned on or off. The microprocessor  308  in the master isolation unit  302  examines the feedback  328  and may generate automated isolation instructions  216  to turn one or more of the remote powered units  104 - 110  on or off based on the feedback  328 . 
     As described above and as an alternative to microprocessor-based remote control of which remote powered units  104 - 110  (shown in  FIG. 1 ) are turned on or off, the control system  200  (shown in  FIG. 2 ) may use various circuits and switches to communicate the isolation instructions  216  (shown in  FIG. 2 ) and to determine whether particular remote powered units  104 - 110  are to act on the isolation instructions  216 . By way of example only, the powered units  102 - 110  (shown in  FIG. 1 ) may include rotary switches that are joined with a trainline extending through the rail vehicle system  100 . Based on the positions of the rotary switches, the remote powered units  104 - 110  may be remotely turned on or off from the lead powered unit  102 . For example, if the rotary switches in each of the lead powered unit  102  and the remote powered units  104 , 106  are in a first position while the rotary switches in the remote powered units  108 ,  110  are in a second position, then the isolation instruction  216  is acted on by the remote powered units  104 ,  106  while the remote powered units  108 ,  110  ignore the isolation instruction  216 . 
       FIG. 4  is a flowchart for a method  400  of controlling a train that includes a lead powered unit and a remote powered unit in accordance with one embodiment. For example, the method  400  may be used to permit an operator in the lead powered unit  102  (shown in  FIG. 1 ) to remotely turn one or more of the remote powered units  104 - 110  (shown in  FIG. 1 ) on or off. At  402 , a user interface is provided in the lead powered unit. For example, the user interface  210 ,  310  (shown in  FIGS. 2 and 3 ) may be provided in the lead powered unit  102 . The master isolation unit  202 ,  302  (shown in  FIGS. 2 and 3 ) also may be provided in the lead powered unit  102 . At  404 , an isolation command is received by the user interface. For example, the isolation command  212  may be received by the user interface  210  or  310 . 
     At  406 , an isolation instruction is generated based on the isolation command. For example, the isolation instruction  216  (shown in  FIG. 2 ) may be generated by the master isolation module  214 ,  314  (shown in  FIGS. 2 and 3 ) based on the isolation command  212 . At  408 - 418 , the isolation instruction is communicated to the slave controllers of the remote powered units in a serial manner. For example, the isolation instruction  216  is serially communicated among the remote powered units  104 - 110  (shown in  FIG. 1 ). Alternatively, the isolation instruction  216  is communicated to the slave controllers  204 - 208 ,  304  (shown in  FIGS. 2 and 3 ) of the remote powered units  104 - 110  in parallel. 
     At  408 , the isolation instruction is communicated to the slave controller of one of the remote powered units. For example, the isolation instruction  216  (shown in  FIG. 2 ) may be communicated to the slave controller  204 ,  304  (shown in  FIGS. 2 and 3 ) of the remote powered unit  104  (shown in  FIG. 1 ). At  410 , the isolation instruction is examined to determine if the isolation instruction directs the slave controller that received the isolation instruction to turn off the engine of the corresponding remote powered unit. If the isolation instruction does direct the slave controller to turn off the engine, flow of the method  400  continues to  412 . At  412 , the engine of the remote powered unit is turned off and flow of the method  400  continues to  418 . On the other hand, if the isolation instruction does not direct the slave controller to turn the engine off, flow of the method  400  continues to  414 . For example, the isolation instruction  216  may be examined by the slave isolation module  222 ,  322  (shown in  FIGS. 2 and 3 ) of the remote powered unit  104  to determine if the isolation instruction  216  directs the remote powered unit  104  to turn off. If the isolation instruction  216  directs the remote powered unit  104  to turn off, the slave controller  204 ,  304  directs the engine  228  (shown in  FIG. 2 ) of the remote powered unit  104  to turn off. Otherwise, the slave controller  204 ,  304  does not direct the engine  228  to turn off. 
     At  414 , the isolation instruction is examined to determine if the isolation instruction directs the slave controller that received the isolation instruction to turn on the engine of the corresponding remote powered unit. If the isolation instruction does direct the slave controller to turn on the engine, flow of the method  400  continues to  416 . At  416 , the engine of the remote powered unit is turned on. For example, the isolation instruction  216  (shown in  FIG. 2 ) may be examined by the slave isolation module  222 ,  322  (shown in  FIGS. 2 and 3 ) of the remote powered unit  104  (shown in  FIG. 1 ) to determine if the isolation instruction  216  directs the remote powered unit  104  to turn on. If the isolation instruction  216  directs the remote powered unit  104  to turn on, the slave controller  204 ,  304  directs the engine  228  (shown in  FIG. 2 ) of the remote powered unit  104  to turn on. On the other hand, if the isolation instruction does not direct the slave controller to turn the engine on, flow of the method  400  continues to  418 . 
     At  418 , the isolation instruction is communicated to the slave controller of the next remote powered unit. For example, after being received and examined by the slave controller  204 ,  304  (shown in  FIGS. 2 and 3 ) of the remote powered unit  104  (shown in  FIG. 1 ), the isolation instruction  216  is conveyed to the slave controller  204 ,  304  of the remote powered unit  106  (shown in  FIG. 1 ). Flow of the method  400  may then return to  410 , where the isolation instruction is examined by the next remote powered unit in a manner similar to as described above. The method  400  may continue in a loop-wise manner through  410 - 418  until the remote powered units have examined and acted on, or ignored, the isolation instruction. 
     In another embodiment, the method  400  does not communicate and examine the isolation instructions in a serial manner through the remote powered units. Instead, the method  400  communicates the isolation instruction to the remote powered units in a parallel manner. For example, each of the remote powered units  104 - 110  (shown in  FIG. 1 ) may receive the isolation instruction  216  (shown in  FIG. 2 ) in parallel and act on, or ignore, the isolation instruction  216  in a manner described above in connection with  410 - 414 . 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the invention, they are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure. 
     This written description uses examples to disclose several embodiments of the invention, including the best mode, and also to enable any person skilled in the art to practice the embodiments of invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.