U.S. patent application number 11/731003 was filed with the patent office on 2007-10-04 for device for activation and monitoring of a light-signal system for railway traffic.
This patent application is currently assigned to Tiefenbach GmbH. Invention is credited to Gotz Dittmar, Walter Pyschny, Ralf Siebelds.
Application Number | 20070228223 11/731003 |
Document ID | / |
Family ID | 38191099 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070228223 |
Kind Code |
A1 |
Dittmar; Gotz ; et
al. |
October 4, 2007 |
Device for activation and monitoring of a light-signal system for
railway traffic
Abstract
A method for operating the signal installation of a railroad
trackage block, whereby at least one first local control unit and
one second local control unit are dedicated to the signal
installation. Each local control unit is capable of transmitting at
least one control signal so that the signal installation is
operated in a first functional mode when at least one control unit
transmits the said minimum of one control signal, the signal
installation is operated in a second functional mode when the first
and the second control units transmit a control signal independent
of each other, and the signal installation is operated in the first
functional mode when the control signal of the first control unit
and that of the second control unit are mutually inconsistent
(malfunction). The method and the associated device advantageously
permit the safe operation of the signal installation of a railroad
block.
Inventors: |
Dittmar; Gotz; (Bochum,
DE) ; Pyschny; Walter; (Duisburg, DE) ;
Siebelds; Ralf; (Koln, DE) |
Correspondence
Address: |
CESARI AND MCKENNA, LLP
88 BLACK FALCON AVENUE
BOSTON
MA
02210
US
|
Assignee: |
Tiefenbach GmbH
|
Family ID: |
38191099 |
Appl. No.: |
11/731003 |
Filed: |
March 29, 2007 |
Current U.S.
Class: |
246/28R |
Current CPC
Class: |
B61L 27/0061 20130101;
B61L 5/1881 20130101 |
Class at
Publication: |
246/028.00R |
International
Class: |
B61L 21/00 20060101
B61L021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2006 |
DE |
10 2006 014 802.9 |
Apr 12, 2006 |
DE |
10 2006 017 628.6 |
Claims
1. A method for operating a signal installation of a rail-road
trackage block, whereby at least one first local control unit and
one second local control unit are dedicated to said signal
installation, each local control unit being capable of transmitting
at least one control signal, characterized in that the signal
installation is operated in a first functional mode when at least
one control unit transmits the control signal for the safe-state
traffic signal (e.g. stop mode), the signal installation is
operated in a second functional mode when, in mutually independent
fashion, the first control unit and the second control unit
transmit the said minimum of one control signal (go mode), and the
signal installation is operated in the first functional mode when
the control signal of the first control unit and that of the second
control unit are mutually inconsistent (malfunction)
2. The method as in claim 1, whereby the control signals of the
first control unit and the second control unit are compared in at
least one of the control units.
3. The method as in claim 2, whereby said comparison of the control
signals is performed over a preselectable time span.
4. The method as in claim 1 or 2, whereby a central signal
controller transmits a single- or dual-channel control command to
the control units.
5. The method as in claim 4, whereby, based on said control
command, the control units determine a setpoint functional mode and
transmit a corresponding control signal.
6. The method as in claim 5, whereby each control unit monitors
whether the signal installation is operating in the setpoint
functional mode and transmits a control signal that can be assigned
to the monitored functional mode of the signal installation.
7. The method as in claim 4, whereby the central signal controller
communicates with the first control unit and the second control
unit via at least one of the following means: a) Electromagnetic
radiation; b) Light; c) Bus systems (e.g. RS485, TCP/IP); d)
Supply-voltage modulation.
8. The method as in claim 1 or 2, whereby each control unit
compares the control signal of at least one other control unit with
its own control signal.
9. The method as in claim 1 or 2, whereby troubleshooting is
performed on at least part of the signal installation and/or on the
control units.
10. The method as in claim 1 or 2, whereby a second control signal
is assigned to the second functional mode and the signal
installation is again operated in the second functional mode when,
in mutually independent fashion, the first control unit and the
second control unit transmit said second control signal.
11. The device for operating a signal installation of a railroad
trackage block, encompassing at least one first local control unit
and one second local control unit, each control unit being capable
of transmitting at least one control signal, characterized in that
each control unit comprises means for monitoring the functional
mode of the signal installation, means for comparing the detected
functional mode with a control signal of another control unit, as
well as means for transmitting the functional mode detected in the
form of a control signal, each control unit being so designed as to
permit the operation of the signal installation in a first
functional mode when at least one control unit transmits a first
control signal while also permitting the operation of the signal
installation in that first functional mode when the control signals
of the first control unit and of the second control unit are
mutually inconsistent.
12. The device as in claim 11, in which the control units are
designed to permit the operation of the signal installation in a
second functional mode when, in mutually independent fashion, the
first control unit and the second control unit transmit the said
minimum of one control signal.
13. The device as in claim 11, in which the control units are
designed to permit the operation of the signal installation in a
second functional mode when, in mutually independent fashion, the
first control unit and the second control unit transmit a second
control signal.
14. The device as in one of the claims 11 to 13, equipped with at
least one communication interface for maintaining a connection to a
central signal processor.
15. The device as in claim 14, in which the communication interface
(9) permits data transmission via at least one of the following
means: a) Electromagnetic radiation; b) Light; c) Bus systems (e.g.
RS485, TCP/IP); d) Supply-voltage modulation.
16. The device as in one of the claims 11 to 13, in which at least
one of the control units (3, 4) is so designed as to permit the
troubleshooting of at least part of the signal installation (2)
and/or of the device (1).
17. The device as in one of the claims 11 to 13, in which the local
control units (3, 4) are electrically separated from each
other.
18. The device as in claim 14, in which the communication interface
(9) is electrically and/or optically separated from the local
control units (3, 4).
19. The device as in one of the claims 11 to 13, in which the
device (1) is provided with a housing that constitutes an
electromagnetic shield at least around parts of the device.
20. A system for the activation and monitoring of a
railroad-traffic signal installation, with a central signal
controller and with transmission lines connecting to the signal
installation for the activation and deactivation as well as the
monitoring of the signals, characterized in that, provided in close
proximity to the signal installation is a local light-signal
operating device comprising two local control units, each of which
is connected via at least one transmission line to the central
signal processor, to the signal installation at the other end as
well as to means serving to monitor the functional mode, in a
manner whereby each control unit, independent of the respective
other control unit, can perform the activation, deactivation and
monitoring of the signal installation, and that both control units
are mutually interconnected and programmed in a manner whereby each
control unit monitors the status of the respective other control
unit and switches the signal installation into the first functional
mode if within a predefined time span after each switching
operation the signal status of the other control unit is not
identical to its own signal status.
Description
[0001] The object of this invention is a method and a device for
operating a signal installation within a railroad trackage block
based on the modular activation of local control units either at
the site of the signal installation or as locally dedicated units,
as conceptually specified in claim 1 and claim 10,
respectively.
[0002] Prior art has employed control devices for railroad
installations where each signal installation is centrally
controlled from a telecontrol master station. The term signal
installation in this case refers in particular to a light signal
which, for example, directs the access to a track section by
appropriate signal switching.
[0003] Against that background it is the objective of this
invention to introduce a method and a device for operating a signal
installation of a railroad block by means of which it is possible
to ensure safest, modular operation and configuration of the signal
installation.
[0004] This objective is achieved by means of a method and a device
with the characterizing features specified in the respective
independent claims. The various dependent sub-claims are aimed at
advantageous design enhancements.
[0005] According to the invention, the method for operating the
signal installation of a railroad block, whereby at least one first
local control unit and one second local control unit are dedicated
to the signal installation, each control unit capable of
transmitting at least one control signal, is based on a concept
whereby the signal installation is operated in a first functional
mode when [0006] at least one control unit transmits a minimum of
one control signal (OR-relation) [0007] the signal installation is
operated in a second functional mode when the first and the second
control units transmit the said minimum of one control signal
(AND-relation), and [0008] the signal installation is operated in
the first functional mode when the control signal of the first
control unit and the control signal of the second control unit are
mutually inconsistent.
[0009] Specifically, the term first functional mode refers to a
safe condition in which any endangerment of the railroad traffic
can be reliably prevented. A safe functional mode, in particular,
is a state in which the signal installation displays a warning
signal and especially a stop or comparable signal. In that fashion,
the inventive method ensures at all times the operation in the safe
functional mode even if only one of the dedicated local control
units transmits the first control signal. That first control signal
is the control signal which in normal operation is designed to
switch the signal installation into the first functional mode. The
minimum of one second functional mode encompasses all other
functional modes of the signal installation. In particular, it may
include the display of various different signals implemented in the
signal installation. For example, each of these second functional
modes may have assigned to it a second control signal of its own,
so that the transmission of the second control signal triggers the
corresponding second functional mode, which may in turn take place
via the AND-relation. According to the invention, the signal
installation will be switched into or operated in a second
functional mode only when both control units transmit the
appropriate second control signal. In the event of a discrepancy
between the control signals transmitted by the first and the second
control units, specifically if one control unit transmits the first
control signal and the other control unit transmits a second
control signal, the signal installation will run in the first
functional mode, thus preventing any endangerment of the rail
traffic. The control units are preferably implemented with a
suitable microprocessor. A control signal as defined for the
purpose of this patent application specifically is constituted of a
signal that switches the signal installation into a particular
functional mode and a signal by means of which the status of a
functional mode determined by the control unit is transmitted.
[0010] In a desirable enhancement of the method according to the
invention, the control signals of the first and the second control
units are mutually compared in at least one of the control
units.
[0011] Each of the control units is preferably designed to permit
an internal comparison of the control signals. Specifically, the
intrinsic control signal of each control unit also defines a
functional mode determined and monitored by the control unit
concerned.
[0012] In another advantageous implementation of the method
according to the invention, the comparison of the control signals
extends over a preselectable length of time.
[0013] It is thus possible by the selection of a suitable length of
time to compensate for system lag. Advantageously, the length of
time is so selected as to take into account the usual time lag of
the control units. This will have the desirable effect of
preventing the signal installation from being operated in the first
functional mode even though both control units are transmitting
identical control signals but not in parallel due to system
inertia.
[0014] In another advantageous implementation of the method
according to the invention, a central signal controller transmits a
single- or dual-channel control command to the control units.
[0015] This central signal controller may be constituted of or
integrated in a signal-and-points control box. The central signal
controller transmits to the control units a control command in
response to which the signal installation is to be switched into a
particular second functional mode. The control units receive and
process that control command. Specifically, a given control command
of the controller is transferred to the signal installation to
cause it to operate in the appropriate functional mode specified by
that control command.
[0016] In this connection a particular advantage is offered in
that, based on the control command, a setpoint functional mode is
determined in the control units, triggering a corresponding control
signal.
[0017] In another advantageous implementation of the method
according to the invention, each control unit monitors the signal
installation for proper operation in the setpoint functional mode
and transmits a control signal that can be associated with the
functional mode of the signal installation being monitored.
[0018] As a useful feature, the control signal, transmitted in
essentially continuous fashion, thus permits the determination of
the current functional mode of the signal installation. Since each
control unit transmits a corresponding control signal that
represents the detected setpoint functional mode, a comparison of
the control signals of the individual control units permits the
monitoring of the overall system. As a result, according to the
invention, the signal installation will be operated in the safe
first functional mode whenever there is a discrepancy between the
control signals of the control units.
[0019] In another advantageous implementation of the method
according to the invention, the central signal controller and the
first and second control units communicate with one another via at
least one of the following means:
a) electromagnetic radiation;
b) light;
c) bus systems (e.g. RS485, TCP/IP), and
d) modulation of the supply voltage.
[0020] The term communication via electromagnetic radiation in this
case refers in particular to wireless communication preferably
based on electromagnetic radiation in the radio frequency range.
Communication via light waves includes data transmission untethered
to fiber optics conductors, for instance by means of a suitably
operated laser. Communication using light waves may also be in the
form of data transmission via optical conductors such as
appropriately configured fiber optic cables. Modulation of the
supply voltage refers in particular to so-called power-line
communication where a voltage serving to power the control units is
suitably modulated, especially frequency-modulated.
[0021] In another advantageous implementation of the method
according to the invention, each control unit compares the control
signal of at least one other control unit with its own control
signal.
[0022] Yet another advantageous implementation of the method
according to the invention includes an error check of at least part
of the signal installation and/or of the control units.
[0023] The signal installation typically encompasses at least one
light source, preferably at least one incandescent lamp or an LED
array. The signal installation is preferably equipped with 4 to 10
incandescent lamps. In addition to a so-called primary filament
each of these incandescent lamps may feature a so-called secondary
filament. The secondary filament is switched on when a break of the
primary filament has been detected. This constitutes additional
redundancy, since a failure of the primary filament does not cause
a failure of the signal installation, given its continued
operability with the secondary filament pending repair of the
primary filament. Specifically, the control units or at least one
control unit are/is so designed as to permit the testing of the
primary as well as the secondary filaments of the individual
incandescent lamps of the signal installation. In addition, at
least certain components of the control units can be tested. To
further augment the operational reliability of the device [sic]
according to the invention, another advantageous enhancement of the
invention provides for a second control signal to be assigned to
the second functional mode, whereby the signal installation will
again be operated in the second functional mode when the first
control unit and the second control unit transmit the second
control signal in mutually independent fashion.
[0024] Another proposed aspect of this invention consists in a
device for operating the signal installation of a railroad trackage
block. It encompasses at least one first local control unit and one
second local control unit. Each control unit is capable of
transmitting at least one control signal. According to the
invention, each control unit includes means for monitoring the
functional condition of the signal installation and means for
comparing the functional mode detected with a control signal of
another control unit as well as means for transmitting a control
signal. Each control unit is designed to permit the operation of
the signal installation in a first functional mode when at least
one control unit transmits the first control signal, and the
operation of the signal installation in the first functional mode
when the control signal of the first and second control units are
mutually inconsistent.
[0025] Specifically, the device according to the invention can be
employed for implementing the method according to the invention. In
particular, each control unit can be in the form of a suitable
microprocessor. The first functional mode is a so-called safe
functional mode which virtually precludes any endangerment of the
railroad traffic. Specifically, the first functional mode of a
light signal is a STOP signal. Employing two control units provides
redundancy which further enhances the dependability of the signal
installation by virtue of a comparison of the control signals
transmitted by the two control units.
[0026] In an advantageous configuration of the device according to
the invention, the control units are so designed that they permit
the signal installation to be operated in a second functional mode
when the first and second control units transmit at least one
control signal independently of each other. In particular, several
second functional modes are possible to each of which an individual
second control signal is assigned.
[0027] As an alternative aimed at further augmenting the
operational reliability of the device according to the invention,
the control units can be so designed as to permit the operation of
the signal installation in a second functional mode when,
independent of each other, the first control unit and the second
control unit transmit a second control signal.
[0028] Another advantageous design version of the device according
to the invention incorporates a communication interface for
maintaining a link to a central controller.
[0029] Maintaining a link means that a connection is established
and sustained. Specifically, the connection may be in wired or
wireless form. The central controller may for instance be part of
an appropriately configured signal-and-points control box
permitting manual or automatic operation.
[0030] In another advantageous design version of the device
according to the invention, the communication interface permits
data transmission via at least one of the following means:
a) electromagnetic radiation;
b) light;
c) bus systems (e.g. RS485, TCP/IP), and
d) modulation of the supply voltage.
[0031] Modulation of the supply voltage involves so-called
power-line communication whereby the supply voltage for the device
according to the invention or for one or both of the control units
or for other components is suitably modulated for data
transmission. Particularly preferred in this context is frequency
modulation.
[0032] In another advantageous implementation of the device
according to the invention, at least one of the control units is so
designed as to permit error-checking of at least part of the signal
installation.
[0033] Specifically, both control units are so designed that,
through the combined action of these control units, part or all of
the signal installation and/or of the device according to the
invention can be tested.
[0034] In another advantageous design implementation of the device
according to the invention, the control units are electrically
separated from one another.
[0035] Electrical separation advantageously enhances the
reliability of the device according to the invention since it
prevents electric interference of a control unit by one of the
other control units.
[0036] In another desirable design configuration of the device
according to the invention, the communication interface is
electrically and/or optically separated from the control units.
Electrical and/or optical separation of the communication interface
from the control units advantageously minimizes the possibility of
interference pulses traveling from the communication interface to
the control units, and vice versa.
[0037] In another advantageous configuration, the device according
to the invention is provided with an enclosure that forms an
electromagnetic shield around at least certain components of the
device. Specifically, the enclosure constitutes a Faraday cage,
shielding in particular the control units and/or the communication
interface against electromagnetic radiation. The electromagnetic
shield preferably provides protection from electromagnetic pulses
or electrostatic discharges.
[0038] The following will once more explain the implementation of
the method and the functionalities of the device for operating a
signal installation from the perspective of its interaction with
the central signal controller.
[0039] The local light-signal operating system includes two
separate control units for instance in the form of microprocessors.
Data transmission via an appropriate interface allows the two
control units to communicate with the central signal controller.
The system can be expanded in a manner whereby both control units
can individually and independently communicate, via a data
transmission line, with the central signal controller in the
signal-and-points control box. The light-signal operating device is
installed locally near the signal installation and communicates
with the central processor (control circuit board, slave board) of
the central signal controller. This communication between the local
light-signal operating system and the central signal controller can
be implemented through power-line, fiber optic cable, databus or
radio transmission. For example--among others--the following light
signals can be activated: [0040] Warning signals, for instance with
2 lamps simultaneously activated; [0041] Main signals for instance
with 2 red, 1 green and 1 yellow lamp(s); [0042] Lead signals:
yellow and green lamps; [0043] Combination signals with white and
green lamps; [0044] Main and lead light signals with red, green
and/or yellow lamps or light sources; [0045] Main and lead signal
combinations with white lamps
[0046] In its basic configuration the device is capable of
individually activating six lamps. Two of these six lamps feature a
primary and a secondary filament, which secondary filament is
independently activated when a break in the primary filament has
been detected. In a suitably expanded system as many as 28 lamps
can be individually activated and monitored.
[0047] The following will explain this invention in more detail
with the aid of the attached figures without limiting the invention
to the implementation examples illustrated therein. In schematic
fashion--
[0048] FIG. 1 depicts a first design example of a device according
to the invention;
[0049] FIG. 2 shows an example of the layout of a control unit;
[0050] FIG. 3 illustrates a second design example of a device
according to the invention;
[0051] FIG. 4 is a first flow chart explaining the method according
to the invention;
[0052] FIG. 5 is a second flow chart explaining the method
according to the invention;
[0053] FIG. 6 is a third flow chart explaining the method according
to the invention;
[0054] FIG. 7 is a fourth flow chart explaining the method
according to the invention;
[0055] FIG. 8 is a first circuit diagram of the signal installation
with a device according to the invention;
[0056] FIG. 9 is a second circuit diagram of the device according
to the invention in conjunction with the signal installation;
[0057] FIG. 10 is a third circuit diagram of the device according
to the invention in conjunction with the signal installation;
[0058] FIG. 11 shows a single-channel data transmission line;
[0059] FIG. 12 shows a dual-channel data transmission line;
[0060] FIG. 13 Flow chart: Response to a command or status
query;
[0061] FIG. 14 Flow chart: Reciprocal check of the
.mu.-processors;
[0062] FIG. 15 Flow chart: A light signal has been activated;
[0063] FIG. 16: Flow chart: A light signal remains activated.
[0064] FIG. 1 depicts a first design example of a device 1
according to the invention serving to operate a signal installation
2 of a railroad trackage block. The device 1 encompasses a first
control unit 3 and a second control unit 4. These control units 3,
4 are designed for local operation, i.e. locally dedicated to the
signal installation 2. Specifically, this means that these units
are not housed in a remote signal-and-points control box but are
located close to the signal installation 2. Each control unit 3, 4
is capable of transmitting a first control signal and at least one
second control signal and of monitoring the functional state of the
signal installation 2.
[0065] FIG. 2 is a detailed schematic illustration of the control
units 3, 4. Each of these control units 3, 4 is provided with means
5 for monitoring the functional state of the signal installation 2,
with means 6 for comparing the functional mode determined with a
control signal of another control unit 3, 4, and with means 7 for
transmitting a control signal.
[0066] According to the invention, each control unit 3, 4 is so
designed as to allow the operation of the signal installation 2 in
a first functional mode when at least one control unit 3, 4
transmits a control signal, and to allow the operation of the
signal installation 2 in a first functional mode when the control
signals of the first control unit 3 and the second control unit 4
are mutually inconsistent. As shown in FIG. 2, the means 5, 6, 7
are connected, via signal lines 8, with one another, with the
signal installation 2 and with the respective other control unit 4,
3. The means 5 for monitoring the functional mode permit the
continuous or discontinuous read-out of the functional mode of the
signal installation 2. As a result of such monitoring, the signal
installation 2 may be operated in a first functional mode or a
second functional mode, or a defect is detected in the signal
installation 2. The comparison means 6 perform a comparison of the
functional mode detected by the means 5 with the control signal of
the respective other control unit 4, 3 and, where indicated, with
its own control signal transmitted by the means 7. In the event the
comparison means 6 detect a discrepancy between the control signals
transmitted by the first control unit 3 and the second control unit
4, the signal installation 2 will automatically be caused to
operate in the first, safe functional mode. In addition, a
corresponding alert message may be sent to a central controller,
advising it of a malfunction in the signal installation 2 and/or
one of the control units 3, 4.
[0067] The device 1 according to the invention includes a
communication interface 9 permitting data transmission via
electromagnetic radiation, a databus, light waves and/or a
modulation of the supply voltage for the device 1 and/or the
control units 3, 4. This may for instance be in the form of a
so-called power-line modem, a fiber optic converter or a wireless
modem. The communication between the control units 3, 4, which are
connected via corresponding links 10 with one another and with the
communication interface 9, preferably takes place through a
so-called RS485 interface. The links 10 are preferably implemented
in redundant fashion so that, if one of the links 10 were to fail,
the device 1 according to the invention can still be operated.
[0068] By way of the communication interface 9, setpoint functional
modes of the signal installation 2 can be communicated to the
control units 3, 4. The functional mode of the signal installation
2 is to be established on the basis of this setpoint functional
mode. By way of the links 10 between the signal installation 2 and
the first and second control units 3, 4, the control units 3, 4 can
read out the respective current functional mode of the signal
installation 2. Similarly by way of these links 10, appropriate
control signals can be transmitted by the control units 3, 4 to the
signal installation 2 in order to change or, as the case may be,
maintain the current functional mode of the signal installation
2.
[0069] According to the invention, the signal installation 2 is
operated in a first functional mode when at least one control unit
3, 4 transmits the first control signal. In other words, a first
control signal transmitted by one of the control units 3, 4 will
switch the signal installation 2 into its first functional mode
and/or will operate it in that mode. In contrast thereto, only both
control units 3, 4 together can bring about a second functional
mode of the signal installation 2 in that both control units 3, 4
transmit the minimum of one matching control signal to the signal
installation 2. That signal congruity is verified in both control
units 3, 4. To that effect the control signal of the control unit 3
or 4 concerned is transmitted via the links 10 to the respective
other control unit 4, 3 for a comparison with its own control
signal and/or with the functional mode of the signal installation 2
as detected by that control unit 4, 3. If one of the control units
3, 4 determines that the control signals of the control units 3, 4
are not identical, the signal installation 2 will automatically
shift into the first functional mode and will be operated in that
mode.
[0070] The inventive method and the inventive device thus permit a
redundant control operation of the signal installation 2 whereby,
if a system component such as a control unit 3, 4 or any part of
the control unit 3 or 4 were to fail, the signal installation 2 is
automatically switched into the safe first functional mode and
operated in that mode.
[0071] FIG. 3 is a schematic illustration of a second design
example of a device 1 according to the invention. It differs from
the first design example in that instead of one communication
interface 9 it is equipped with two communication interfaces 9,
each of which is redundantly connected to both control units 3, 4
via appropriate links 10.
[0072] FIG. 4 is a first diagrammatic flow chart explaining the
method according to the invention. In procedural step 100, the
communication interface 9 receives a command intended to switch the
signal installation 2 into a setpoint functional mode. Step 100
also forwards that command via the communication interface 9 to the
control units 3, 4. Preferably, the control units 3, 4 are
addressed individually, allowing the control units 3, 4 in step 101
to determine whether that command is intended for them. In step 102
it is decided that the target address is the address of the control
unit 3, 4. If the control unit 3, 4 finds that it is not the
intended recipient of the command, no further action will take
place. In step 103 the control unit 3 executes the command. In step
104 the command concerned is monitored by the first control unit 3.
In corresponding fashion, the second control unit 4 executes the
command in step 105 and monitors in step 106 the execution of the
command. In step 107 the second control unit 4 relays the
respective status to the first control unit 3. In step 108, the
first control unit 3 compares the status received by the first
control unit 3 through the monitoring of the signal installation 2
with the status received by the second control unit 4 through the
monitoring of the signal installation 2. For the comparison in this
procedural step as in all other procedural steps involving a
comparison, a preselectable length of time is allowed, i.e. there
is a wait for the duration of the preset time period before the
comparison is made.
[0073] If in procedural step 108 the status information of the
first control unit 3 and that of the second control unit 4 are not
identical, then in step 109 the first control unit 3 will cause the
signal installation 2 to be operated in the first functional mode.
In step 110 the first control unit 3 sends its status message to
the communication interface 9 through which the data will be
forwarded to a central controller.
[0074] Step 110 will also be performed when the status messages of
both control units 3, 4 in step 108 are identical. Concurrently in
step 110, the status of the signal installation 2 determined by the
first control unit 3 is sent to the second control unit 4. In step
111, the second control unit 4 compares the status of the signal
installation 2 reported by the first control unit 3 with the status
of the signal installation 2 determined by the second control unit
4. If that status is identical, then in step 112 the second control
unit 4 as well will send its status message to the communication
interface 9 to be forwarded to the central controller. In
procedural step 111, there is again a wait for a predefined length
of time before the comparison is made.
[0075] If the comparison made by the second control unit 4 (in step
111) turns out negative, meaning that the first control unit 3 and
the second control unit 4 have each arrived at a different status
of the signal installation 2, then in step 113 the second control
unit 4 will switch the signal installation 2 into the first
functional mode. In step 114 the second control unit 4 will
transmit that status to the communication interface 9. Through
steps 114 and 110 in which the communication interface 9 and,
beyond it, the central controller have been informed of the current
status of the control units 3, 4, any malfunction that triggers the
switching of the signal installation 2 into its first functional
mode and its operation in that mode will come to the attention of
the central processor, permitting appropriate troubleshooting.
Operation in the first functional mode may in advantageous fashion
allow the activation of an automatic train warning system such as a
so-called inductively operated automatic train-running control.
[0076] FIG. 5 is a flow chart illustrating the communication
between the two control units 3, 4. Such communication between the
two control units 3, 4 is implemented in particular on the basis of
a so-called CAN network (controller area network). In procedural
step 200, the second control unit 4 transmits to the first control
unit 3 the status of the signal installation 2 as detected by it.
In step 201 the first control unit 3 compares the status of the
signal installation 2 as determined by the control unit 3 with the
status of the signal installation 2 as determined and forwarded by
the control unit 4. If the two status messages match, the first
control unit 3 will send to the second control unit 4 the status of
the signal installation 2 as determined by it. If step 201 reveals
that the two status messages do not match, the first control unit 3
will, initially in step 203, address the signal installation 2 so
as to cause it to operate in the first functional mode, while in
step 202 sending to the second control unit 4 the status
information determined by it. In step 204 the second control unit 4
compares the status of the signal installation 2 as determined by
the second control unit 4 with the status of the signal
installation 2 forwarded by the first control unit 3. In steps 204
and 201 a comparison is made with the data from a predefined period
of time, i.e. there is a wait for a preselected duration before the
comparison concerned is made. This allows for the fact that the lag
of the different control units 3, 4 and the run times of the
signals from the control units 3, 4 to the signal installation 2
and back are of a certain duration. If the comparison in step 204
reveals identical status information, the process continues with
step 200. If the check in step 204 reveals diverging status
information, then in step 205 the second control unit 4 will
address the signal installation 2 so as to cause it to operate in
the first functional mode, proceeding from there to procedural step
200.
[0077] The flow chart in FIG. 6 shows how the signal installation 2
is switched into a second functional mode. That may for instance be
the activation or retention of a light signal other than a STOP
signal. The initial premise in step 300 is that the signal
installation 2 is being operated in its first functional mode,
meaning in particular that the signal installation 2 is in the STOP
mode. In step 301 the second control unit 4 receives the command to
operate the signal installation 2 in a different functional mode.
In other words, step 301 relays to the second control unit 4 a
setpoint functional mode. Thereupon, in step 301, the second
control unit 4 causes the signal installation 2 to shift into its
second functional mode. In analogous fashion, the first control
unit 3 receives in step 302 the command to operate the signal
installation 2 in a setpoint functional mode. The first control
unit 3 causes the signal installation 2 to change over into its
setpoint functional mode. In steps 301, 302 a central controller
sends out the commands which are received by the communication
interface 9 and forwarded via the links 10 to the control units 3,
4.
[0078] In step 303 the second control unit 4 determines the status
of the signal installation 2 and forwards that status information
to the first control unit 3. In step 304 the first control unit 3
determines the status of the signal installation 2 and forwards
that status information to the second control unit 4. The term
status of the signal installation 2 refers in particular to the
detected setpoint functional mode of the signal installation 2. In
step 305 the control units 3, 4 compare the status determined by
them with the status information received from the respective other
control unit 3, 4. If there is a match (step 306), the result will
be the state shown in 307, whereby the signal installation 2 is
operated in its second functional mode that corresponds to the
predefined setpoint functional mode. If the result of the
comparison in step 305 is as shown in 306, meaning that the two
status messages are not identical, then in step 308 one of the
control units 3, 4 will switch the signal installation 2 into a
second [sic] functional mode, operate it in that mode and send a
corresponding message to the central controller via the
communication interface 9.
[0079] FIG. 7 is another flow chart explaining the method according
to the invention. Following the state shown in 400 where the signal
installation 2 is operated in the first functional mode, the first
control unit 3 checks the status of the signal installation 2 in
step 401. In step 402, the first control unit 3 transmits that
status information, constituting a control signal, to the second
control unit 4 at least once but preferably several times. In step
405 the second control unit 4 checks the status of the signal
installation 2. In step 406 the second control unit 4 transmits
that status information to the first control unit 3 at least once
but preferably several times. In step 403 the first control unit 3
compares the status of the signal installation 2 as determined by
the first control unit 3 with the status of the signal installation
2 as received from the second control unit 4. If there is a match,
the process continues with step 400, with the operation of the
signal installation 2 continuing in the second functional mode.
[0080] In step 408 the second control unit 4 compares the status
determined by the second control unit 4 with the status of the
signal installation 2 reported by the first control unit 3. If the
two status messages are identical, the process continues with
procedural step 400. If in step 403 and in step 408 the status
messages are not identical, the signal installation 2 will be
switched into its first functional mode and a corresponding message
will be transmitted to the central controller via the communication
interface 9.
[0081] FIG. 8 is a schematic diagram of the circuitry that serves
to shift the signal installation 2 into its first functional mode.
A power supply 11 connects to an incandescent lamp 15 via a drop
resistor 12, a first switch 13 and a second switch 14. The first
switch 13 consists of the first control unit 3 or is a component of
it and/or is a switch controlled by it. The second switch 14
consists of the second control unit 4 or is a component of it
and/or is a switch controlled by it. Specifically, these may be
relays that are activated by the associated control unit 3, 4. The
incandescent lamp 15 is an incandescent lamp that is lit in the
first functional mode of the signal installation 2. Specifically,
this is a red incandescent lamp constituting a STOP signal. The
circuitry further includes a first precision resistor 16 and a
second precision resistor 17. These precision resistors 16, 17
function as so-called shunt resistors. Measured in this process is
the voltage drop across these precision resistors 16, 17 or the
current flowing through these precision resistors 16, 17. Applying
Ohm's law, the measured variables can be mutually converted. In
principle it is possible to provide one single precision resistor
16, 17; however, using two precision resistors 16, 17 according to
the invention offers the advantage of a redundant design permitting
a further improvement of the measuring accuracy. With the measured
variables thus established, various test cycles can be run for
testing different components of the signal installation 2 and/or of
the device 1.
[0082] A first test cycle can be run during the transition from the
first functional mode to a second functional mode of the signal
installation 2. In addition to a primary filament of the
incandescent lamp 15 there is a so-called secondary filament which
could be incorporated in the same incandescent lamp or it could
constitute a second incandescent lamp. The control units 3, 4 are
equipped with a so-called automatic secondary-filament activation
circuit which in the event of a defective primary filament in the
incandescent lamp 15 will automatically activate the secondary
filament assigned to it. The test cycle initially causes the first
and the second control units 3, 4 to deactivate the automatic
secondary-filament detection. Next, the second switch 14 of the
second control unit 4 turns off the primary filament of the
incandescent lamp 15. At that point it is possible to check whether
the first switch 13 of the first control unit 3 is closed. This is
accomplished by means of the above-mentioned measured variables,
given that the current flowing through the precision resistors 16,
17 must remain constant. Next, the second switch 14 of the second
control unit 4 reactivates the primary filament of the incandescent
lamp 15. Thereupon the first switch 13 of the first control unit 3
turns off the corresponding primary filament of the incandescent
lamp 15. It can now be checked whether the switch 14 of the second
control unit 4 is closed. In this case as well the current measured
at the precision resistors 16, 17 must remain constant. The first
control unit 3 then turns on the automatic secondary-filament
activation circuit. As the next step, the second switch 14 of the
second control unit 4 deactivates the primary filament of the
incandescent lamp 15. This permits verification of the proper
operating condition of the automatic secondary-filament activation
circuit in the first control unit 3 which must now turn on the
secondary filament. Again, the measured current should remain
constant. Next, the second control unit 4 turns on the automatic
secondary-filament activation circuit while the first control unit
3 turns off its automatic secondary-filament activation circuit.
This allows verification of whether the automatic
secondary-filament activation circuit of the second control unit 4
is intact. Throughout this test cycle, assuming proper operating
condition of all elements, the current measured across the
precision resistors 16, 17 must remain essentially constant.
[0083] With the first functional mode of the signal installation 2
turned off, this test cycle permits the automatic testing of other
components of the control units 3, 4. Additional functions can be
tested when the signal installation 2 is shifted into its first
functional mode, for instance when the STOP signal is activated. To
that effect, for example, both the first control unit 3 and the
second control unit 4 turn off the automatic secondary-filament
activation circuit. Next, the second switch 14 of the second
control unit 4 turns on the primary filament of the incandescent
lamp 15. This allows verification of whether the second switch 14
is closed. The first control unit 3 on its part then activates the
primary filament of the incandescent lamp 15. Next, the second
switch 14 of the control unit 4 turns off the primary filament of
the incandescent lamp 15. This permits verification of whether the
first switch 13 of the first control unit 3 is closed. Thereupon
the second switch 14 of the second control unit 4 reactivates the
primary filament of the incandescent lamp. Next, the automatic
secondary-filament activation circuits of the first and second
control units 3, 4 are turned on again. During the switching of all
elements involved throughout this test cycle the current measured
across the precision resistors 16, 17 must remain essentially
constant.
[0084] This second test cycle, with the second functional mode
turned off, lends itself very well to the testing of the elements
involved.
[0085] A third test cycle can be run while the signal installation
2 is in its first functional mode. To that effect, with the system
in operation, the automatic secondary-filament activation circuits
of the first and second control units 3, 4 are turned off. Next,
the second switch 14 of the second control unit 4 deactivates the
primary filament of the incandescent lamp 15. This allows
verification of whether the switch 13 of the first control unit 3
is closed. In that case the current across the precision resistors
16, 17 will remain essentially constant. Thereupon, the first
control unit 3 turns on the automatic secondary-filament activation
circuit. Next, the first control unit 3 deactivates the primary
filament of the incandescent lamp 15. This permits verification of
whether the automatic secondary-filament activation circuit of the
first control unit 3 is intact.
[0086] In a subsequent step the second control unit 4 turns on the
automatic secondary-filament activation circuit while the first
control unit 3 turns its automatic secondary-filament activation
circuit off. This permits verification of whether the automatic
secondary-filament activation circuit of the second control unit 4
is intact. Following that, the first control unit 3 turns on its
automatic secondary-filament activation circuit. Next, the second
control unit 4 activates the primary filament of the incandescent
lamp 15. This permits verification of whether the second switch 14
of the second control unit 4 is intact. Thereupon the first control
unit 3 reactivates the primary filament of the incandescent lamp
15. Throughout this entire test cycle, if all components tested
function properly, the current measured across the precision
resistors 16, 17 must remain essentially constant.
[0087] FIG. 9 is a schematic diagram of a circuit system serving to
activate an additional light signal, i.e. to operate the signal
installation 2 in a second functional mode. In principle, the
signal installation 2 can be operated in several different
functional modes. In contrast to the schematic diagram shown in
FIG. 8, this circuitry includes a third switch 18 in the first
control unit 3 and a fourth switch 19 in the second control unit 4.
These switches are connected in series so as to activate the second
incandescent lamp 20 when both switches 18 and 19 are closed at the
same time.
[0088] FIG. 10 is another schematic diagram of a circuit system for
the signal installation 2 operating in a second functional mode.
This schematic diagram will show how an additional incandescent
lamp 20, when turned off, can be tested via the control units 3, 4.
Here, the function of the first switch 18 and the second switch 19
is tested as well. To that effect the second control unit 4 is
provided with a fifth switch 21 and the first control unit 3 is
provided with a sixth switch 22. For the test, the second control
unit 4 opens the fifth switch 21 while the first control unit 3
closes the sixth switch 22. Next, the first control unit 3
activates the third switch 18. This allows the detection of a
short-circuit in the fourth switch 18 [sic]. Next, the second
control unit 4 activates the fourth switch 19. This permits the
detection of a broken filament in the second incandescent lamp 20.
Thereupon the first control unit 3 deactivates the third switch 18.
That permits the detection of a short-circuit in the third switch
18. As the next step, the second control unit 4 deactivates the
fourth switch 19. Next, the second control unit 4 opens the sixth
switch 22 while the first control unit 3 closes the fifth switch
21. During the test a low test current flows through the circuit,
low enough not to light up the incandescent lamp 20. This test
serves to check the switches 18, 19, 21, 22 of the control units 3,
4 as well as the corresponding filaments of the second incandescent
lamp 20. This test as well is based on the monitoring of the
current that flows through the precision resistors 16, 17. If all
components are intact, the current should remain essentially
constant throughout the test.
[0089] In FIG. 11, the central controller 23 in the
signal-and-points control box with its PLC modem (or alternatively
with a fiber optics converter, a bus system or a wireless modem) is
connected via two conductors with both the first control unit 3
(hereinafter also referred to as "microprocessor 3" or ".mu.C1")
and the second control unit 4 (hereinafter also referred to as
"microprocessor 4" or ".mu.C2"), locally installed in immediate
proximity to a signal installation (not illustrated). For signal
transmission and for transferring the command signals each of the
microprocessors 3/.mu.C1 and 4/.mu.C2 connects to the signal
installation 2 via a link 10 and to function-mode monitoring means
5 via signal control lines 8. In addition, both microprocessors are
interconnected via (network) links 10. This circuit configuration
performs the following functions: [0090] 1.) In mutually
independent fashion, both .mu.Cs monitor the status of the light
signal. [0091] 2.) By way of (a) CAN interface(s) both .mu.Cs
communicate with each other, reporting to the respective other
.mu.C the current status/functional mode. [0092] 3.) In mutually
independent fashion, each of the .mu.Cs is capable of switching the
light signal into the safe mode in which the light signal indicates
STOP. [0093] 4.) To activate a GO signal both .mu.Cs must perform
identical activation routines. [0094] 5.) Both .mu.Cs receive from
the central signal controller 23 in the signal-and-points control
box the commands transmitted to the interface via a modem or in
general via a data communication device (or even for instance an
RS485 port).
[0095] If, as depicted in FIG. 1, the data transmission between the
central signal controller 23 and the microprocessors employs a
common modem, the following applies: [0096] 1.) Both .mu.Cs send
their status information to the central controller via that sole
modem. [0097] 2.) Both .mu.Cs receive at one of their RS485 ports
that which the respective other .mu.C is sending to the modem.
[0098] 3.) If that status information sent to the modem differs
from its own status information, the .mu.C concerned unilaterally
switches the light signal into the STOP state, which will be
recognized by the other .mu.C.
[0099] If, as illustrated in FIG. 12, the data transmission between
the central signal controller 23 and the microprocessors employs
one modem for each, meaning a total of 2 modems, the following
applies: [0100] 1.) Using separate transmission lines, both .mu.Cs
send their status information to the signal-and-points control box.
[0101] 2.) Both .mu.Cs receive at one of their RS485 ports that
which the respective other .mu.C is sending to the modem. [0102]
3.) If that status information sent to the modem differs from its
own status information, the .mu.C concerned unilaterally switches
the light signal into the STOP state, which will be recognized by
the other .mu.C. [0103] 4.) The decision as to what will take place
next is made by the central controller in the signal-and-points
control box.
[0104] As soon as the local signal-operating device 1 detects a
disruption of the communication with the central signal controller
23 (for instance if the timer has run out), the local
signal-operating device must switch over into the safe signal mode.
In other words, the STOP signal will be activated when there is no
communication between the local light-signal operating device 1 and
the central signal controller 23. The STOP signal will also be
activated when there is no communication with the signal control
unit(s), which will be detected by the central signal controller 23
from where a corresponding command will be forwarded to the local
signal operating device 1. Without depending on a command from the
central signal controller 23, a STOP signal is also activated when
the two .mu.Cs show a discrepancy in their monitoring results.
[0105] In the event the light-signal operating device 1 loses
power, the signal will be dark, which is tantamount to a STOP
signal.
[0106] The local light-signal activating device will continuously
check the various "filaments" (PFR, SFR, PFW, position light),
permitting in the event of a failure an immediate message to be
sent to the central signal controller 23 before a line-clear signal
for a track section is needed.
[0107] Similarly, the operation of a signal installation by an
appropriately enabled automatic train stop or warning system (AWS,
an inductive safety system for automatic signal activation by the
train) is controlled by the local light-signal operating device 1.
With the aid of the AWS, a train that runs a STOP signal will be
automatically brought to a stop. The AWS is activated when the
signal is set on STOP. The AWS consists of a track magnet in an
aluminum housing that is "electrically open" toward the top. The
track magnet connects to a parallel-resonant circuit consisting of
a coil and a capacitor that is tuned to a specific frequency, for
instance f.sub.1=500 Hz. If through a contact the resonant circuit
is energized, an electric locomotive that transmits at the same
frequency will be automatically brought to a stop as it reaches the
track magnet. However, if a substitute signal or a written command
is to allow a train to pass a malfunctioning main signal that shows
STOP, without being automatically halted, a special AWS command key
can bypass the frequency-based stop action.
[0108] With reference to the flow charts in FIGS. 13 to 16, the
following will describe and explain the flow of commands and
signals between the central signal controller 23, the
microprocessors 3, 4, the signal operating device 1 and the signal
monitors.
[0109] The two .mu.Cs communicate with each other via the CAN
interface. Since in mutually independent fashion both .mu.Cs
perform the signal activation and monitoring, the communication
between the two .mu.Cs must be continuous. The moment one .mu.C
reports its status to the other, that other .mu.C must check its
own status for congruity: If within a preselected time span an
identical monitoring result is not found, the .mu.C must switch the
signal into the safe functional mode. In this context it should be
noted that either .mu.C can independently set the signal in the
safe mode. Run-related settings (such as MS1, MS2, position light
etc.) can only be made jointly. Therefore, prior to any reciprocal
status check, a certain delay in the progression is needed to give
the other .mu.C enough time to perform the activation
concerned.
[0110] The circuitry is laid out based on the principle of
"non-reactivity and maximum isolation of the internal from the
external system". Therefore, the circuitry is preferably
implemented with optically controlled components, in particular
MOSFETs, photovoltaic relays, fiber-optic couplers, linear
optoelectronic couplers, current sensor modules each with a linear
optoelectronic coupler.
[0111] In conjunction with the shunt resistor it will be necessary
to ensure a high EMC level and thus maximum isolation of the
internal system from the outside system.
[0112] The STOP signals should be turned on and off along a given
sequence to ascertain proper function of the two switches. During
an extended On-state it is possible to test the individual switches
without that being visible from the outside.
[0113] The inventive method and the inventive device 1
advantageously permit the safe operation of the signal
installations 2 of railroad trackage blocks. The method and device
1 according to the invention ensure that in the event of a
malfunction within the control electronics the signal installation
2 will always be operated in a safe first functional mode for
instance in the form of a STOP signal.
LIST OF ABBREVIATIONS
[0114] bps Bits per second (transmission rate) [0115] CAN
Controller Area Network [0116] COMPEX Computer, explosion-proof
[0117] CRC Cyclic redundancy code [0118] LLSAD Local light-signal
activation device [0119] ES European standard [0120] ESD
Electrostatic discharge [0121] PFR Primary filament, red [0122] PFW
Primary filament, white [0123] MLLS Main and lead light signal
[0124] MS Main signal [0125] ID Identifier [0126] AWS Automatic
warning system [0127] kbps 1024 bits per second (transfer rate)
[0128] CS Combination signal [0129] kV 1000 volts (electric
voltage) [0130] LED Light-emitting diode [0131] FOC Fiber-optic
cable [0132] Mbps (1024).sup.2 bits per second (transfer rate)
[0133] SFR Secondary filament, red [0134] P2P Point-to-point,
direct communication [0135] PLC Power-line communication [0136]
RS485 Recommended Standard-485 [0137] SIL Safety integration level
[0138] ST Safety stop (railroad signals, e.g. ST_0, ST_1) [0139]
MLSC Main and lead signal connections [0140] Div Divider [0141]
.mu.C Microprocessor [0142] VAC Volts, alternating current [0143]
VDC Volts, direct current [0144] LS Lead signal [0145] MY
Marshalling yard
LIST OF REFERENCE NUMBERS
[0145] [0146] 1 Device [0147] 2 Signal installation, light signal
activation system [0148] 3 First control unit, microprocessor,
.mu.C1 [0149] 4 Second control unit, microprocessor, .mu.C2 [0150]
5 Means for monitoring the functional mode [0151] 6 Means for
comparison [0152] 7 Means for transmitting the control signal
[0153] 8 Signal cables/junctions [0154] 9 Communication interface
[0155] 10 Links, network, microprocessor interconnection, signal
and command transmission lines [0156] 11 Power supply [0157] 12
Drop resistor [0158] 13 First switch [0159] 14 Second switch [0160]
15 Incandescent lamp [0161] 16 First precision resistor [0162] 17
Second precision resistor [0163] 18 Third switch [0164] 19 Fourth
switch [0165] 20 Second incandescent lamp [0166] 21 Fifth switch
[0167] 22 Sixth switch [0168] 23 Central signal controller (central
processing unit/CPU) [0169] 100 . . . 408 Procedural steps
* * * * *