Abstract:
An electronic control system ( 20 ) for an electropneumatic brake for a rail vehicle having a power trainline ( 18 ), comprising a battery ( 34 ); a functional control module ( 30 ) and a power management module; wherein the functional control module ( 30 ) includes a brake controller for the electropneumatic brake, an interface to the power trainline, a transceiver for receiving brake signals, a power supply circuit deriving a power supply from the power trainline ( 18 ), and a control management controller for the transceiver and the power supply circuit; and wherein the power management module includes a battery charging circuit connected to the power supply and a power controller for the battery charging circuit and the power supply circuit.

Description:
BACKGROUND AND SUMARY OF THE INVENTION  
       [0001]     The present invention relates to electropneumatic brake control on a train and more specifically to the electronic portion of the car electropneumatic brake control.  
         [0002]     Electropneumatic brake control valves are well known in the passenger railroad art and the mass transit railroad art. Because the trains are short and are not involved generally in a mix and match at an interchange of different equipment the ability to provide pneumatic and electrical control throughout the train has been readily available in the passenger and the mass transit systems. In freight trains, the trains may involve as much as 100 cars stretching over one mile or more. The individual cars may lay idle in harsh environments for up to a year without use. Also, because of the long distance they travel, the cars are continuously moved from one consist to another as it travels to its destination. Thus, the use of electropneumatic-pneumatic valves in the freight trains has been very limited.  
         [0003]     A prior art system with electropneumatic train brake controls is illustrated in  FIG. 1 . An operator control stand  10  generally has a pair of handles to control the train braking. It controls a brake pipe controller  12  which controls the brake pipe  14  running throughout the train. It also includes a trainline controller  16  with power source  17  which controls the trainline  18  which is a power line as well as an electrical communication line. The operator control stand  10 , the brake pipe controller  12  and the trainline controller  16  are located in the locomotive.  
         [0004]     Each car includes a car control device  20  having a car ID module  22  and a sensor  24  connected to the trainline  18 . The pneumatic portion of the car brakes include a brake cylinder  26 , a reservoir  28  and a vent valve  29 . The car control device  20  is also connected to the brake pipe  14  and the trainline  18 . The brake pipe controller  12  is available from New York Air Brake Corporation as CCBII® and described in U.S. Pat. No. 6,098,006 to Sherwood et al. The trainline controller  16  and the CCD  20  are also available from New York Air Brake as a product known as EP60®. The car control device is described in U.S. Pat. No. 5,967,620 to Truglio et al. and U.S. Pat. No. 6,049,296 to Lumbis, et al. Each of these patents and products are incorporated herein as necessary for the understanding of the present patent. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIG. 1  is an electropneumatic brake control system of the prior art.  
         [0006]      FIG. 2  is a block diagram of the car control device according to the principles of the present invention.  
         [0007]      FIG. 3  is a block diagram of the functional control module of the car control device of the present invention.  
         [0008]      FIG. 4  is a block diagram of the trainline gateway module of the functional control module according to the principles of the present invention.  
         [0009]      FIG. 5  is a block diagram of the control management module of the functional control module according to the principles of the present invention.  
         [0010]      FIG. 6  is a block diagram of the brake control module of the functional control module according to the principles of the present invention.  
         [0011]      FIG. 7  is a block diagram of the power management module according to the principles of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]     The car control device  20  is shown in detail in  FIG. 2 . It includes a functional control module  30  which is connected to the trainline T/L to receive power off the trainline  18  as well as to communicate to the trainline controller  16  over the trainline. It also provides power and communication to the car ID  22 , the sensor  24  and a vibration sensor (not shown). Other auxiliary devices, for example, empty/load, hot wheel detector, may be connected to and powered by the CCD 20 . As described in the Lumbis U.S. Pat. No. 6,049,296, the car ID  22  and its sensor are used in an automatic train serialization. The car vibration sensor preferably is within the car control device  20  for added protection reduced wire length and improved accuracy of measurement.  
         [0013]     The car control device  20  also includes a power management module  32  connected to the functional control module  30  to control the charging of battery  34 . The battery is charged off the trainline T/L and used in combination with an off-line power source included in the functional control module  30  to provide the necessary power for the car control device  20 . The functional control module  30  and power management module  32  are on individual circuit boards and one in a common housing with the battery.  
         [0014]     The electropneumatic brake valve  36  is also connected to the functional control module  30  and is in the common housing. A pressure sensor module PSM, which includes pressure sensors for brake pipe BP, brake cylinder BC, a reservoir ER and the brake control # 16 , communicates with the functional control module  30 . The functional control module  30  also provides control of the electropneumatic valves supply valve, exhaust valve and electropneumatic isolation valve EPI. The control brake cylinder relay BC RELAY, which provides signals to the brake cylinder port BC. It also includes a port VV for the vent valve  29  of  FIG. 1 . The details of the electropneumatic brake valve  36  are described in detail in the Truglio et al. U.S. Pat. No. 5,967,620.  
         [0015]     Although the illustrations in  FIGS. 1 and 2  are for a stand alone system, which is only electropneumatic braking, it will also apply to an overlay system wherein the electropneumatic brake valve  36  may be used with a full pneumatic brake control valve, for example, a DB60 available from New York Air Brake. Such illustrations are shown in the Truglio et al. U.S. Pat. No. 5,967,620.  
         [0016]     While the functional control module  30  includes a transceiver for communication on a network over the trainline  18 , it also includes a neuron network to interconnect with various neuron nodes within the functional control module  30  and to communicate with the power management module  32 , also in the neuron network. The network of choice by the industry is Lonworks.  
         [0017]     The functional control module FCM  30 , illustrated in detail in  FIG. 3 , includes three sections, namely a trainline gateway module TLGM  40 , a brake control module BCM  60  and a control management module CMM  50 . The trainline gateway module TLGM provides an interface between the trainline T/L and power management module  32  and the functional control module  30 . Inputs/outputs T/L+ and T/L− are to the trainline  18 . The interface with the power management module  32  includes a system voltage +SYSV, ground GND and network ports NETA and NETB. NETA and NETB are the network communications of the network between the modules and the nodes. As will be explained below, the control signal is the pulse width modulating signal PWM received from the power management module  32  to control the system off-line power source in the trainline gateway module  40 .  
         [0018]     Within the functional control module  30 , the trainline gateway module  40 , the brake control module  60  and the control management module  50  are interconnected in a network by NETA and NETB.  
         [0019]     The trainline gateway module  40  includes a power supply circuit, a trainline transceiver and the trainline gate circuit. The power supply circuit produces a power supply driven off the trainline. It provides a trainline status signal T/L STATUS to the control management module CMM. The control management module  50  also provides a DISABLE and a SHUT DOWN signal to the trainline gateway module TLGM. The SHUT DOWN signal activates a switch to shut down the connection to the trainline and offer high impedance.  
         [0020]     The DISABLE signal disables the transceiver in the trainline gateway module  40 . A resynchronization signal RESYNC received from the CMM restarts and resynchronizes the trainline transceiver.  
         [0021]     A transmission level signal XMIT LEVEL from the CMM is provided to a sensor circuit in the TLGM which determines whether the transceiver is transmitting or not. A current limit signal CURRENT LIMIT is also provided from the CMM to the TLGM where it is used in a current limiting circuit to determine whether the current is too high and thereby modify the system power supply in combination with the CONTROL signal PWM from the power management module  32 . The trainline gateway module TLGM will be described in detail with respect to  FIG. 4 .  
         [0022]     The brake control module BCM  60  has four analog inputs AD 0 , AD 1 , AD 2  and AD 3  from the pressure sensor module PSM of  FIG. 2  as well as a power terminal plus +5 REFA and ground AGND. The brake control module BCM also includes output signals, APPLY, RELEASE and EPI to control the solenoid valves in the control valve module CVM of  FIG. 2 . The brake control module BCM will be discussed in detail with respect to  FIG. 6 .  
         [0023]     The control management module CMM  50  includes a transceiver to communicate with a car ID module  22  and the sensor  24  at ports FTNETA and FTNETB. It also provides power to the car ID  22  at terminals CAR ID PWR, to the 24 at terminal SENSOR PWR as well as the ground signals GND. CMM  50  would send commands to the car ID module  22  to collect the ID to be reported, command applying a load during serialization to collect detected current in the trainline during serialization and to collect the current detection in the load during serialization. The control management module CMM also provides power to the vibration sensor at terminal UIB PWR and GND and receives a signal from the vibration sensor at terminal VIB. If the vibration sensor is a node, the signals can be received on FTNETA, FTNETB.  
         [0024]     The control management module CMM also receives a signal OVERLAY on its overlay terminal which indicates whether the car control device is operating at stand alone or overlay mode. This signal OVERLAY may be produced by a switch or a jump wire connected to the OVERLAY terminal and the adjacent GND terminal in the CVM. Other auxiliary inputs and power outputs may be provided to the car control device  20  through the functional control module  30 . These could include an empty/load device, hot wheel detector, etc.  
         [0025]     As discussed with respect to the trainline gateway module TLGM, the car management module CMM receives a TRANSMIT signal from TLGM and the trainline status TL STATUS signal from TLGM. It provides to TLGM the current limiting signal CURRENT LIMT, the transmit level signal TXMIT level, a shut down signal SHUT DOWN and the disable signal DISABLE. The CMM uses the TRANSMIT signal to determine whether the trainline transceiver in the TLGM is stuck-on in a transmitting mode. If the trainline transceiver is stuck in transmission, CMM sends out a DISABLE signal to the TLGM. The CMM also uses the trainline status signal T/L STATUS, which is a digital value. The CMM sends a shut down signal SHUT DOWN to the TLGM to shut down the connection to the trainline of the off-trainline power supply. This prevents the power supply from interfering with the trainline during serialization using voltages below the normal operating range. Sequencing is usually conducted in the 20-30 VDC range. A more detailed explanation of the control management module CMM will be discussed in  FIG. 5 .  
         [0026]     The trainline gateway module  40  is illustrated in detail in  FIG. 4 . The trainline terminals T/L are connected to a rectifying bridge  402 . Fuses and varistors (not shown) provide input protection and filter  401  provides AC isolation from the DC trainline T/L. The bridge  402  is connected to a transformer  404  by a high voltage DC bus  406 . Connected to the bus  406  is a voltage sensor  408 . The voltage sensors  408  controls the switch  410 , which when off, disconnects the return path for the primary of transformer  404  and an off-line power supply  414  connected to high power line  406  by line  416 . When the voltage sensor  408  senses that the trainline voltage T/L has risen to a predetermined voltage range, it turns switch  410  on providing the return path. In that the operating voltage is a minimum of 100 volts, this voltage may be in the range of 50-80, for example. A shut down signal SHUT DOWN from the control management module CMM  50 , via optical isolator  411  and line  412 , controls the switch  410  to shut the power supply  414  down and disconnect the transformer  404 .  
         [0027]     The power supply  414 , connected across the primary of the transformer  404 , is shown as DC to DC converter  414 . It is basically a current mode pulsed width modulated controller with an internal MOSFET. The DC to DC converter  414  may be, for example, a TOP,  224 G top switch. A feedback from transformer  404  on line  418  provides a bias voltage for the DC to DC converter  414 . The switch&#39;s duty cycle is regulated by a current which is fed into the control pin  419  so as to maintain a regulated voltage on the output  416 . A feedback network, including a programmable shunt  420 , is connected to and provides drive current into the control pin  419  via optical isolator  421 . The output of the secondary of transformer  404  provides a signal feedback over line  426  to comparator  428 .  
         [0028]     The CURRENT LIMIT signal from the control management module  50  provided on input  430  to the comparator  428  with the signal  426 . The result of this comparison is provided to switch  432 . If the current on  426  at the output of the transformer  404  is greater than the CURRENT LIMIT provided on  430 , switch  432  is activated as an input to programmable shunt  420 . Also provided as an input to programmable shunt  420  is CONTROL or pulse width modulated signal PWM from the power management module  32  on-line  422 . These two signals control the shunt  420  which determines the current that drives pin  419  of the DC to DC converter  414 .  
         [0029]     The supply voltage to the CCD electronics is derived from two sources, namely the off-line DC to DC converter  414  and the battery  34 . The two sources are diode ORed together to provide the system power signal +SYSV. This +SYSV signal on line  424  is provided via line  436  to a voltage regulator  438 . The various voltages are then tapped from line  436  and the output of regulation  438 .  
         [0030]     The shunt  420  is set, for example, at approximately 2.5 volts DC. When the system voltage +SYSV falls below the reference voltage, shunt  420  acts to decrease the sunk current at input  419  to the DC to DC converter  414 .  
         [0031]     The duty cycle of PWM DC to DC converter  414  is inversely proportional to the control current. Thus, this drop at terminal  419  causes the cycle to increase which increases the output voltage of the transformer  404 . As this output voltage increases, the system voltage +SYSV increases. In response thereto, the shunt  420  sends more current, thereby increasing the input at  419  of the PWM DC to DC converter  414  thereby decreasing its duty cycle and the output of transformer  404 . In this manner, the programmable shunt  420  regulates the output voltage of the DC to DC converter  414  and +SYSV.  
         [0032]     Also connected to the trainline T/L+ and T/L− is a transceiver  444  via transformer  440  and filter  442 . Transceiver  444 , for example, may be a PLT- 10 A. The transceiver  444  is connected to the internal network NETA and NETB by a trainline gateway node  446 . This may be a neuron. A current sensor  448 , for example, a current mirror, senses the current drawn by the transceiver  414  and provides it as a voltage input to a comparator  450 . The other input to comparator  450  is the transmit level TXMIT LEVEL received from the car management module CMM 50 . The transceiver  444  uses more current in the transmission mode than in the receiving mode. The transmit level signal TXMIT LEVEL on  452  is greater than the receiving mode current and less than the transmitting node current. Thus, the output of converter  450  determines that the transceiver  454  is in the transmitting mode. The TRANSMIT signal is provided back to the CMM  50  to be used in a stuck on transmitter detector.  
         [0033]     Reset circuit  456  generates a reset signal during power up to reset terminals  458  for the trainline gateway node  446  and  460  of the transceiver  444 . The reset terminals are interconnected by a diode  462 . Also connected to these reset terminals is the RESYNC signal at line  464  received from the CMM  50 . The reset signal  456  or the resynchronization signal RESYNC are simultaneously applied to both the reset terminals  458  and  460 . The DISABLE signal on line  466  from the CMM  50  is provided to the reset terminal  460  of the transceiver  444 . This disables the transceiver  44  without resetting the trainline gateway node  446 . The diode  462  prevents this from occurring. The DISABLE signal retains the transceiver  444  at its reset state which stops the transceiver  444  from transmitting. As shown in  FIG. 5 , the car management module node  50  includes a transceiver  501  transmitting signals between the neuron on the car ID circuit and the trainline sensor circuit and the control management node  506  via router  524 . The transceiver may be, for example, an FTT-10 transmitting over twisted pairs. A switch  508 , a switch  510  and a switch  511  connect the output of the car module controller  506  to the car ID power, the line sensor and vibration sensor modules. Latches  512  and  513  monitor the output of the switches and feeds it back to the control management node  506 . The car ID and vibration sensor modules provide signals to the control management node  506  via FTNETA, B. A latch  514  also holds the OVERLAY input from the control valve module CVM at the input of the control management node  506 .  
         [0034]     The control management node  506  receives the TRANSMIT signal signifying the transmitting mode of the trainline transceiver  444  from TLGM  40 . It measures the amount of time that the transmit signal is present and if it exceeds a predetermined time, it considers this a stuck on transmitter. This time, for example, may be a ½ of a second. The CMN  506  will then transmit a DISABLE signal to the TLGM  40  to disable the transceiver  444 . If the CMN decides to reinitialize and resynchronize the transceiver  444  and the TL gateway node  446 , it transmits a RESYNC output to the TLGM  40 . A latch  516  maintains the RESYNC signal high until reset.  
         [0035]     A digital to analog converter  518  takes the digital outputs of the CMN  506  and provides analog signals CURRENT LIMIT and XMIT LEVEL to the TLGM  40 . A latch  520  also latches the value of the trainline T/L STATUS received from TLGM  40 . The CMN  506  may also provide a SHUT DOWN signal to TLGM  40  to shut down the DC to DC converter  414 .  
         [0036]     Four indicators or light emitting diodes LEDS  522  are controlled by the CMN  506 . They indicate health, T/L status, comm status and brake control status. A router  512  is also provided on the NETA and NETB terminals of the CMN  506 .  
         [0037]     The CMN  506  via transceiver  501  may receive signals from the trainline controller  116  to limit the amount of watts drawn from the trainline  18 . This value can be used to set the current limit which is an input to the control circuit for the DC to DC converter  414 . Also, upon receipt of a signal from the trainline, it may issue the SHUT DOWN signal. Battery charging may also be performed using the method described in U.S. Pat. No. 5,647,562 to Lumbis, et al.  
         [0038]     The brake control module  60  is illustrated in  FIG. 6 . A brake control node  602 , which is shown as a neuron, is connected by NETA and NETB to the trainline gateway module  40  and the control management module  50 . The digital control signals for the APPLY, RELEASE and EPI valves of the EP brake valve  36  are provided on lines  604 ,  606  and  608  respectfully to latch  610 . The latch  610  is reset by a watchdog circuit reset  612  via line  613 . The watchdog circuit  612  responds to the absence of a strobe signal on line  611  from brake control node  602 . The output of the latch  610  drives switches  614 ,  616  and  618  to provide an analog signal to the apply, release and output lines respectfully.  
         [0039]     Data signals from the BCN  602  on line  620  are converted by a digital to analog converter  622  to digital output signals DA 1  and DA 2  on line  624  and  626  respectfully. An A/D converter  628  receives feedback signals from the APPLY, RELEASE, DA 1  and DA 2  ports and provides them over line  630  as digital input signals to BCN  602 . A/D converter  628  also receives the analog signals AD 0 , AD 1 , AD 2  and AD 3  from the four pressure sensors in the pressure sensing module PSM of the electropneumatic brake valve  36 .  
         [0040]     The power management module  32  is illustrated in detail in  FIG. 7 . The system power supply voltage +SYSV is provided at line  402  and is connected to voltage regulatory  404  that produces voltage B 6 . Line  402  is also connected to the charging/discharging circuit  406 . A charging leg  408  connected to line  402  includes transistor  410  and zener diode  412 . The discharge leg  416  includes transistor  418  and zener diode  420 . The charge and discharges legs are in antiparallel arrangements. A slow charge leg  422  includes zener diode  424  and resistor  426 . This allows slow charging when the charge and discharge legs are not active. They are all connected to line  414  which is the positive terminal of the battery +BTTY.  
         [0041]     The power management node PMN  430  is a neuron and it provides a charge signal over line  432  to control transistor  410  and a discharge signal over line  434  to control discharge transistor  418 . The positive side of the battery on line  414  is connected via line  436  to a battery voltage sensor  438 .  
         [0042]     The battery voltage VBTTY is provided over line  440  to the PMN  430 .  
         [0043]     A battery current sensor  442  is connected to the negative terminal of the battery −BTTY via line  441 . Battery current IBTTY is provided on line  440  to the PMN  430 . The battery current is also provided over line  446  to over current circuit  448 . If the battery current, for example, during charging, is above a preselected limit, then the over current circuit  448  produces an output on line  450  to control switch  452  to turn off transistor  410  of the charging leg  408 . This will override any signal online  432  from the PMN  430 .  
         [0044]     A temperature sensor  454  is provided as one input to a multiplex  458 . The second input is a reference input  456 . The temperature sensor  454  may be a temperature to frequency device whose voltage output is proportional to the temperature. PMN  430  via line  460  determines the state of the multiplexer  450  to determine whether the output of the voltage sensor  454  or the reference in voltage on  456  is provided as an input via line  462  back to the PMN  430 .  
         [0045]     If the input from the temperature sensor  454  is selected, the PMN will then convert the frequency into a voltage. The PMN compares, based on the selected signal on line  462 , the temperature sensor  454  or the reference input  456  with the information received from the battery voltage sensor  438  or the battery current sensor  442  to provide the control signal PWM as an input to the shunt  420  of the DC to DC converter  414  of TLGM  440 . This controls the power supply circuit portion of the system voltage +SYSV. By controlling +SYSV, the value of the battery charged by the charging circuit  406  is adjusted. This adjusts the charging current and ultimately, the final voltage of the battery.  
         [0046]     PMN  430  also has the ability of monitoring the battery capacity. PMN  430  monitors the battery current received from battery current sensor  442  over periods of time and accumulates the current times time period over time. For example, if the battery current is measured every second, the value of the current which can be added directly and accumulated. Thus, the capacity accumulated would be, in for example, milliamps-seconds. Every 3600 seconds, the accumulated value can be converted to milliamps-hours. This value is stored in the PMN  430  and also can be reported out to the network for NETA and NETB.  
         [0047]     PMN  30  assumes that at start up that the battery capacity and power up to zero. Once powered and the battery is connected to the system, the only way for the battery to be disconnected under control is for the battery terminal to drop below a lower limit. Once below this lower limit, which is above zero, the battery is assumed to be exhausted and will have a zero capacity. Should the battery be disconnected by a service technician and be replaced, it would also assume a zero capacity in the accumulator. Upon replacement, the PMN  430  will determine the actual battery capacity by monitoring the charging conditions as it advances through the charging modes and based on how the battery responds. The capacity will only be adjusted based on this determination.  
         [0048]     Although the stuck-on transmission mode has been described with respect to the CCD  20 , the same circuitry can be provided in the trainline controller  16 . Also, other elements of the CCD  20  which are common to the trainline controller  16  may be provided therein.  
         [0049]     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.