Abstract:
A method of serialization including establishing a parameter along a length of the train between a node on one of the cars and one end of the train. The presence of the parameter at each node is determined and the parameter is removed. The sequence is repeated for each node on the train. Finally, serialization of the cars is determined as a function of the number of determined presences of the parameter for each node. The parameter can be established by providing at the individual node, one at a time, an electric load across an electric line running through the length of the train and measuring an electrical property, either current or voltage, at each node. To determine the orientation of a car, each node include two subnodes. The operability of each node is determined by counting the presence and then the absence of a parameter along the whole train.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 08/713,347 filed Sep. 13, 1996 now abandoned. 
    
    
     The present invention relates generally to trainline communications and more specifically, to the serialization of cars in a train. 
     With the addition of electropneumatically operated train brakes to railway freight cars comes a need to be able to automatically determine the order of the individual cars in the train. In an EP brake system utilizing a neuron chip or other &#34;intelligent circuitry&#34;, a wealth of information is available about the status of each car in the train. But unless the location of the car in the train is known, the information is of little value. It has been suggested that each car report in at power-up. While this provides information on which cars are in the train consist, it does not provide their location in the consist. Also, in some trains, the direction the car or locomotive is facing or orientation in the train is required. Typical examples are rotary dump cars and remotely located locomotives. 
     Present systems address this issue by requiring that the order of the cars in the train be manually entered into a data file in the locomotive controller. While this does provide the information necessary to properly locate each car in the train, it is very time consuming when dealing with long trains, and must be manually updated every time the train make-up changes (i.e. when cars are dropped off or picked up). The present invention eliminates the need for manually entering this data by providing the information necessary for the controller to automatically determine the location of each car and EP control module or node in the train. 
     Historically, there has only been a communication link between one or more of the locomotives in a train with more than one locomotive needed. Current EP systems require a communication link between all cars and locomotives in a train or consist. The Association of American Railroads has selected as a communication architecture for EP systems, LonWorks designed by Echelon. Each car will include a Neuron chip as a communication node in the current design. A beacon is provided in the locomotive and the last car or end of train device to provide controls and transmission from both ends of the train. 
     The serialization of locomotives in a consist is well known as described in U.S. Pat. No. 4,702,291 to Engle. As each locomotive is connected, it logs in an appropriate sequence. If cars are connected in a unit train as contemplated by the Engle patent, the relationship of the cars are well known at forming the consist and do not change. In most of the freight traffic, the cars in the consist are continuously changed as well as the locomotives or number of locomotives. Thus, serialization must be performed more than once. 
     The present invention is an automatic method of serialization by establishing a parameter along a length of the train between a node on one of the cars and one end of the train. The presence of the parameter at each node is determined and the parameter is removed. The sequence is repeated for each node on the train. Finally, serialization of the cars is determined as a function of the number of determined presences of the parameter for each node. The parameter can be established by providing, at the individual node one at a time, an electric load across an electric line running through the length of the train. Measuring an electrical property, either current or voltage, at each node determines the presence of the parameter. The line is powered at a voltage substantially lower than the voltage at which the line is powered during normal train operations. Each node counts the number of parameters determined at its node and transmits the count with a node identifier on the network for serialization. 
     To determine the orientation of a car within the train, a local node is provided with a primary and secondary node adjacent a respective end of the car. In the sequence, the parameter is established for the car having a primary and secondary node using at least the primary node. Determination of the presence of the parameter uses both primary and secondary nodes. The use of the primary node alone to establish the parameter is sufficient to determine the orientation of the car. Alternatively, both the primary and secondary node may be sequentially activated to establish a parameter. 
     Prior to establishing a parameter along a length of the train, a count of the number of the cars in the train and their identification of each car is obtained. After the sequence of establishing the number of presences of the parameter for each car is completed, the count of the number of the cars in the train is compared with the number of cars which transmit a count. Preferably, determining the presence of the parameter includes determining the presence of the parameter at each node except for the node which has established the parameter. 
     Testing operability of the nodes includes establishing a parameter along the length of the train and determine the presence of the parameter at each node. The parameter is then removed and the presence of the parameter at each node is again determined. Operability of the node is determined as a function of presences of the parameter which was determined for each node. 
    
    
     Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a train incorporating electropneumatic brakes and a communication system incorporating the principles of the present invention. 
     FIG. 2 is a block diagram of the electronics in the individual cars of the train incorporating the principles of the present invention. 
     FIG. 3 is a flow chart of the method of serialization according to the principles of the present invention. 
     FIG. 4 is another block diagram of another embodiment of electronics in the individual cars of the train incorporating the principles of the present invention. 
     FIG. 5 is a block diagram of a third embodiment of electronics in the individual cars of the train incorporating the principles of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A train consisting of one or more locomotives and a plurality of cars is shown in FIG. 1. An electropneumatic trainline 10 transmits power and communication to the individual nodes on the cars. A brake pipe 12 provides pneumatic pressure to each of the cars to charge the reservoirs thereon and can fluctuate pressure to apply and release the brakes pneumatically. The locomotive includes a trainline controller 20 which provides the power and the communication and control signals over the EP trainline 10. A brake pipe controller 22 controls the pressure in the brake pipe 12. A power supply 24 receives power from the locomotive low voltage supply and provides the required power for the trainline controller 20 and the EP trainline 10. 
     Each of the cars include car electronics 30 which are capable of operating the electropneumatic brakes as well as providing the necessary communications. The trainline controller 20 and the car electronics 30 are preferably LonWorks nodes in a communication network although other systems and regimens may be used. Car electronics 30 will also provide the necessary monitoring and control functions at the individual cars. With respect to the present serialization method, a sensor 32 is connected to the car electronics 30 to sense the current or voltage of the trainline 10 at each node or car. Preferably, the sensor 32 is a current sensor and may be a Hall effect sensor or any other magnetic field sensor which provides a signal responsive to the current in the trainline 10. Alternatively, the sensor 32 may be a voltage sensor. As will be discussed, the car electronics 30 measures a parameter at its node or car and transmits the results along the trainline 10 to the trainline controller 20. 
     The brake pipe 12 is also connected to the car electronics 30 of each car as well as the air brake equipment(not shown). The car electronics 30 monitors the brake pipe 12 and controls the car&#39;s brake equipment. The trainline&#39;s power and communication is either over common power lines or over power and separate communication lines. The individual communication nodes are also powered from a common power line even though they may include local storage battery sources. 
     A more detailed diagram of the car electronics 30 is illustrated in FIG. 2. The local communication node includes a car control device 31. The car control device 31 includes a Neuron chip, appropriate voltage regulators, memory and a transceiver to power itself and communication with the trainline controller and other cars as a node in the communication network. A LonWorks network is well-known and therefore need not to be described herein. The car control device 31 is capable of operating electropneumatic brakes as well as providing the necessary communication. The car control device 31 can also provide the necessary monitoring control functions of other operations at the individual cars. 
     Cable 36 connects the car control device 31 to the power and communication trainline 10 so as to power the car control device and to provide the necessary communication using the transceiver of the car control device. Preferably, the car electronics includes a battery 33 connected to line 36&#39; of the cable 36 and charged from the trainline 10 by battery charger 35 and power supply 37. The battery 33 provides, for example, 12 volts DC via line 36&#39; and the power supply 37 provides a 24 volts DC via line 36&#34;. The car control device 31 controls the operation of power supply 37 and provides a DC voltage of approximately 12 volts on line 34. The current sensor 32, which is preferably a digital output current sensor, is powered by line 34 and is connected to the trainline 10 by wire 38. The current sensor 32 in combination with load resistor 56, which is selectively connected to the power and communication trainline 10 by relay 54, is used for automatic train serialization. 
     Each of the cars includes a storage device which stores identification data which includes at least the serial number, braking ratio, light weight, and gross rail weight of the car. The storage device is permanently mounted to the car and need not be changed. If there is change in the information, preferably the storage device is programmable. Alternatively, the information may be stored in the car control device 31 if it has sufficient memory. 
     Preferably, a storage device is a communication node 40 of the communication network. The subsidiary node includes a Neuron controller 42 having the car identification data therein and communicates with the car control device 31 by transceiver 44. A DC converter 46 provides, for example, 5 volts power from line 34 to the Neuron 42 and the transceiver 44. The Neuron 42 also receives an output from the digital output current sensor 32 and stores the current information. 
     The Neuron 42 may control an opto-isolator 50 and DC converter 52, which receives its power from line 34, to operate the solid state relay 54 to connect load resistor 56 to the trainline 10. This is used in the current sensing routine for the current sensor 36. The load resistor is part of current sensing and serialization. Alternatively, the car control device 31 may control the opto-isolator 50 and solid state relay 54. 
     The method of train serialization is illustrated in the flow chart of FIG. 3. In order to perform serialization, the head end unit HEU 20 must know the train make up or configuration. After the train is made up, i.e. all cars connected and powered up, the HEU 20 powers up all car control devices 31 using a normal high, for example 230 volts DC, trainline power. The HEU then takes roll call to determine the number and type of cars in the train and stores the information. This roll call can be compared with a manual manifest of the cars. Once the roll call has been taken, the HEU powers down the trainline and then powers up the trainline with a low voltage, for example, 24 volts DC. Once the trainline is powered with 24 volts DC, the HEU requests that each of the car control devices apply a 12 volt DC from their battery 33 to the current sensor 32 and associated serialization electronics. 
     Before the serialization process begins, the current sensors of each car electronics 30 are tested. The head-end unit HEU commands the end of train device EOT to apply its load resistor 56 to the trainline 10. Preferably, this applies a one amp load to the trainline. The head-end device HEU then commands all cars to measure and record the presence of a current. All operable sensors should detect and record a current present. Next, the head-end unit HEU commands the end of train device EOT to remove the load resistor 56. With no load, the head-end unit commands all cars again to measure the presence of current. All operable sensors should measure no current. The results of these two measurements are then transmitted to the head-end unit. All cars that have reported a count of one current detected are operable current sensors. Cars that report zero or two indicate faulty current sensors. The knowledge of operable and inoperable sensors is important to the serialization process. 
     Once the verification of current sensors has taken place, serialization begins. The serialization process will individually and sequentially ask each car to activate its load resistor and request the other cars to determine if trainline current is present. Those cars between the car control device which has applied its load and the head-end unit will detect current. Those cars between the car control device which has the activated load and the end of train will not detect a current. Alternatively, the power supply may be at the end of train device EOT and the presence of current will be from the applied load to the end of the train. At the end of the sequence, the count in each car is reported to the head-end unit which then can perform serialization. 
     As illustrated in FIG. 3, the head-end unit commands one car to apply its load across the train and all car control devices 31 measure the trainline current. If the current sensor 32 senses current, it increments a counter at its car control device. If no current is sensed, it does not increment its counter. The selected car control device then disconnects its load resistor 56 from the line. The head-end unit then determines whether this is the last car in the sequence. If it is not, it repeats the process until all cars have been polled. When the last car has been polled, each car control device reports its present count to the head-end unit. 
     The head-end unit then sorts the cars based on the present counter value. If desired, each car can use the transmitted counts to determine its position in the train consists by comparing its count to those transmitted by other cars. An example of the counts for five nodes as they individually apply a load is illustrated in Table 1 as follows: 
     
                       TABLE 1______________________________________FIG. 2 - not counting self    Neuron ID-Load           Nodes Sensing CurrentApplied     ID1      ID2    ID3    1D4  ID5______________________________________ID3         1        1      0      0    0  ID1           0     0    0     0     0  ID2           1     0    0     0     0  ID5           1     1    1     1     0  ID4           1     1    1     0     0  Total         4    3   2   1    0______________________________________ 
    
     Preferably, the head-end unit commands all cars except the car with the load across the line to measure the presence of the current. Thus, the last car will have a count of zero and the car closest to the head-end unit would have the highest count. 
     A validity check of the serialization can be performed by checking the number of cars that are reported against the number of cars having operable sensors. Only a car with a good current sensor and a count of zero can be the last car. 
     After completion of serialization, the head-end unit switches off the 24 volt DC power from the trainline. It also commands each car control device 31 to terminate the serialization function by turning off the power to their current sensors 32. The head-end unit then applies its normal operating 230 volts DC to the trainline. Alternatively, the serialization may be carried out at the 230 volt DC on the trainline with appropriate protection of the electronic elements. 
     For certain cars, it is important to determine which direction the car is facing or orientation in the train. These may be, for example, rotary dump cars or remotely located locomotives. The method of the present invention may determine the orientation of the car and the locomotive using the embodiment of FIGS. 4 and 5. In FIG. 4, the car whose orientation is required would include a primary communication node 40A and a secondary communication node 40B connected to the car control device 31. It should be noted that the power source connections in FIGS. 4 and 5 have been deleted for sake of clarity. The primary node 40A includes as a current sensor 32, the car ID Neuron 42, the transceiver 44, the opto-isolator 50, the solid state relay 54 and load resistor 56. The secondary node would include only the car ID Neuron 42, the transceiver 44 and the current sensor 32. 
     By locating the load resistor 56 at the primary communication node, the orientation of the cars can be determined. While only the primary node would be used in the sequence of applying the load for the car, both of the current sensors and the car ID Neuron would count the presence of the variable and provide it to the car control device 31. The count of both of the primary and secondary nodes would be transmitted for use in determining the orientation of car as well as the position of the car in the train. The car ID Neurons 40 of the primary and secondary circuits would include the same car ID with an additional bit or letter indicating a particular end of the car or whether it is a primary or secondary circuit. 
     Table 2 illustrates the presence of current at the primary and secondary nodes on five of the cars using the circuit of FIG. 4 and not including its self in the count when it applies the load. 
     
                       TABLE 2______________________________________FIG.  4 - not counting self  Neuron  ID- Nodes Sensing CurrentLoad   ID1      ID2      ID3     ID4    ID5Applied  A     B      B   A    A    B    B   A    A   B______________________________________ID3    1     1      1   1    0    0    0   0    0   0  ID1    0    0     0  0     0   0   0   0    0   0  ID2    1    1     1  0     0   0   0   0    0   0  ID5    1    1     1  1     1   1   1   1    0   0  ID4    1    1     1  1     1   1   1   0    0   0  Total   4    4  4   3   2   2 2  1 0   0______________________________________ 
    
     It is noted that cars of ID2 and ID4 are facing in a different direction than cars of ID1, ID3 and ID5. If the primary or secondary counts are the same, the primary node is forward or closest to the head end unit. If the counts are different, the higher count for a car will determine which orientation of the car. This is evident from Table 2. 
     Alternatively by locating the load resistor 56 between the current sensors 32 of the primary and secondary communication nodes, the orientation of the cars can also be determined. Table 2A illustrates the presence of current at the primary and secondary nodes on five of the cars using the circuit of FIG. 4 and including its self in the count when it applies the load. 
     
                       TABLE 2A______________________________________FIG.  4 - counting self  Neuron  ID- Nodes Sensing CurrentLoad   ID1      ID2      ID3     ID4    ID5Applied  A     B      B   A    A    B    B   A    A   B______________________________________ID3    1     1      1   1    1    0    0   0    0   0  ID1    1   0    0   0    0   0   0   0    0   0  ID2    1   1    1   0    0   0   0   0    0   0  ID5 1 1 1 1 1 1 1 1 1 0  ID4    1   1    1   1    1   1   1   0    0   0  Total   5   4 4       3   3 2 2   1 1   0______________________________________ 
    
     Determining which of the primary or secondary counts are higher for a car will determine which orientation of the car. This is evident from Table 2A. 
     Another embodiment of the present invention which has the capability of determining the orientation of the car is illustrated in FIG. 5. Each of the primary and secondary nodes 40A and 40B are identical, each including, not only a current sensor 32, ID Neuron 42 and transceiver 44, but also each includes an opto-isolator 50, solid state relay 54 and a load resistor 56. In this instance, each of the primary and secondary nodes are sequentially actuated and treated as separated nodes. The resulting counts during the sequence as well as the totals are illustrated in Table 3. 
     
                       TABLE 3______________________________________FIG.  5 - not counting self  Neuron  ID- Nodes Sensing CurrentLoad    ID1      ID2      ID3    ID4    ID5Applied A     B      B   A    A   B    B   A    A   B______________________________________ID3  A      1     1    1   1    0   0    0   0    0   0   B    1    1    1   1    1    0   0   0    0   0  ID1 A    0    0    0   0    0    0   0   0    0   0   B    1    0    0   0    0    0   0   0    0   0  ID2 A    1    1    1   0    0    0   0   0    0   0 B    1    1    0   0    0    0   0   0    0   0  ID5 A    1    1    1   1    1    1   1   1    0   0   B 1 1 1 1 1 1 1 1 1 0  ID4 A    1    1    1   1    1    1   1   0    0   0 B    1    1    1   1    1    1   0   0    0   0Total   9     8      7   6    5   4    3   2    1   0______________________________________ 
    
     Table 3 includes not counting the node in which the load is applied. This results in numbers 1-9. If the node which the node load is applied is included in the count, each of the numbers would be increased by 1 and therefore the count would be 1-10. In the example of Table 3, the cars of ID2 and ID4 are facing in a different direction than the cars of ID1, ID3 and ID5. 
     Although the example has shown all car nodes having two nodes, the train could and generally would have only some of the cars requiring orientation information. Thus, either all of the cars could include dual nodes or only those for which orientation information is required. 
     The present serialization method has been described with respect to using a load resistor 56 and current sensors. The current is a parameter which can be measured over a specific length of train and sequentially selected. As previously discussed, a voltage sensor may be used in lieu of a current sensor. Also, the brake pipe 12 may also be used to establish a parameter between one of the cars and an end of the train. This will require the ability to isolate the brake pipe from one car and one end of the train from the brake pipe from the car to the other end of the train and the ability to create difference in pressure in each portion. The car electronics 30 would also require the ability to sense the conditions in the brake pipe. If such equipment and capabilities are available on the car, the present process can be performed by sequentially commanding modification of the brake pipe pressure at each of the cars and monitoring a response at the other cars. 
     Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.