1
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
TERMINAL DEVICE AND DATA MANAGEMENT METHOD
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED
AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
5 Field
[0001] The present invention relates to a terminal
device including a plurality of processing devices and a
data management method.
10 Background
[0002] In railway systems in related art, a central
control device transmits data to on-board control devices
on trains and to ground control devices, to share data to
control operations of the trains. Patent Literature 1
15 discloses a technology by which an activation informing
signal is transmitted upon power-on of an on-board control
device of a train, and a central control device in receipt
of the activation informing signal downloads the latest
data to be stored in an on-board database onto an on-board
20 control device, and downloads the latest data to be stored
in a ground database onto a ground control device, so that
the latest data are shared among the devices. In addition,
the on-board control device described in Patent Literature
1 can include two on-board databases including an on-board
25 database for normal use and an on-board database for backup
in order to improve reliability.
Citation List
Patent Literature
30 [0003] Patent Literature 1: Japanese Patent Application
Laid-open No. 2006-321264
Summary
3
Technical Problem
[0004] The technology of the related art is based on the
assumption that the two on-board databases store the same
data. If a situation in which one of the on-board
databases cannot receive data occurs 5 in the process of
storage of data in the on-board databases, the data in one
of the two on-board databases becomes different from that
in the other on-board database. When the operation is
switched from the on-board database for normal use to the
10 on-board database for backup under such a situation, there
is a problem of the difference in the stored data between
the two databases being a possible source of an accident.
[0005] The present invention has been made in view of
the above, and an object thereof is to provide a terminal
15 device including a plurality of processing devices, the
terminal device being capable of reducing the difference
between data stored in databases of the processing devices.
Solution to Problem
20 [0006] To solve the aforementioned problems and achieve
the object, the present invention provides a terminal
device comprising a plurality of processing devices,
wherein the processing devices each includes: a database; a
state managing unit to manage data stored in the database;
25 a request managing unit to determine data to request from
an external system and an order in which the data is to be
requested from the external system on the basis of a
management state of the data in the state managing unit, a
management state of data in a state managing unit of
30 another processing device, and a type of predetermined
event requiring data in a case where the predetermined
event has occurred, the request managing unit being capable
of requesting data from the external system on the basis of
4
the order; and an obtainment managing unit to manage a
state of obtainment of data from the external system. A
request managing unit of a predetermined processing device
requests data from the external system.
5
Advantageous Effects of Invention
[0007] According to the present invention, the terminal
device including a plurality of processing devices produces
an advantageous effect of reducing the difference between
10 the data stored in the databases of the processing devices.
Brief Description of Drawings
[0008] FIG. 1 is a diagram illustrating an example of a
configuration of a train control system.
15 FIG. 2 is a diagram illustrating an example of a
configuration of a safety device included in a train.
FIG. 3 is a chart illustrating an example of timings
at which processing devices receive data from a traffic
control system in the safety device.
20 FIG. 4 is a block diagram illustrating an example of a
configuration of a processing device included in the safety
device.
FIG. 5 is a table illustrating an example of version
management information held by a state managing unit of the
25 processing device.
FIG. 6 is a table illustrating an example of a second
request queue generated by a request managing unit of the
processing device.
FIG. 7 is a table illustrating an example of data
30 obtainment management information held by an obtainment
managing unit of the processing device.
FIG. 8 is a first flowchart illustrating a process of
requesting data from the traffic control system by the
5
processing device in the safety device.
FIG. 9 is a second flowchart illustrating the process
of requesting data from the traffic control system by the
processing device in the safety device.
FIG. 10 is a third flowchart illustrating 5 the process
of requesting data from the traffic control system by the
processing device in the safety device.
FIG. 11 is a diagram illustrating an example of a case
where processing circuitry included in the safety device is
10 implemented by a processor and a memory.
FIG. 12 is a diagram illustrating an example of a case
where processing circuitry included in the safety device is
constituted by dedicated hardware.
15 Description of Embodiment
[0009] A terminal device and a data management method
according to an embodiment of the present invention will be
described in detail below with reference to the drawings.
Note that the present invention is not limited to the
20 embodiment.
[0010] Embodiment
FIG. 1 is a diagram illustrating an example of a
configuration of a train control system 60 according to an
embodiment of the present invention. The train control
25 system 60 includes a traffic control system 50, and trains
11, 12, 13, 21, 31, and 32. The train control system 60 is
a system in which the traffic control system 50 controls
operations of trains 11, 12, 13, 21, 31, and 32 via a
communication network 40.
30 [0011] The communication network 40 is a network
connecting the traffic control system 50 with the trains 11,
12, 13, 21, 31, and 32. The communication network 40 may
be a dedicated network, or a general-purpose network such
6
as the Internet.
[0012] The traffic control system 50 includes a database
51. The database 51 stores the latest data necessary for
controlling operations of the trains 11, 12, 13, 21, 31,
and 32. The traffic control system 5 50, which is an
external system, transmits data stored in the database 51
to the individual trains and shares the data with the
individual trains for controlling the operations of the
individual trains. In addition, the traffic control system
10 50 transmits, to the trains 11, 12, 13, 21, 31, and 32,
data version information indicating the latest version of
data stored in databases of the individual trains.
[0013] In the train control system 60, different kinds
of trains may operate. In FIG. 1, assume, for example,
15 that the trains 11, 12, and 13 are trains from A Company,
the train 21 is a train from B Company, and the trains 31
and 32 are trains from C Company. Pieces of data necessary
for the operations of the different kinds of trains can
differ from one another. In other words, data necessary
20 for train operations may vary among the trains 11, 12, and
13 in an A Company group 10, the train 21 in a B Company
group 20, and the trains 31 and 32 in a C Company group 30.
In such a case, in the train control system 60, upon
receiving from each of the trains a request for data, the
25 traffic control system 50 transmits the requested data to
the corresponding one of the trains. As a result, each
train can obtain data necessary for the operation of the
train, and data can be shared between the traffic control
system 50 and the individual trains.
30 [0014] A description will be made as to a process
through which, for example, the train 11 obtains, from the
traffic control system 50, data necessary for the operation
thereof. FIG. 2 is a diagram illustrating an example of a
7
configuration of a safety device 100 of the train 11
according to the present embodiment. The train 11 includes
the safety device 100, and external interface (hereinafter
referred to as I/F) devices 71 and 72. Note that, in FIG.
2, only components necessary for the 5 train 11 to obtain
data from the traffic control system 50 are illustrated,
but common components are not illustrated.
[0015] The safety device 100 is a terminal device
including an active processing device 200, and a standby
10 processing device 300. The active processing device 200
controls the operation of the train 11 during normal
operation. The active processing device 200 includes
processing devices 201 and 202. The processing devices 201
and 202 of the active processing device 200 perform
15 identical computation processes, and when the computation
results match each other, the active processing device 200
controls the operation of the train 11 on the basis of the
computation results. The standby processing device 300
controls the operation of the train 11 instead of the
20 active processing device 200 when the active processing
device 200 is not operating normally because of, for
example, a breakdown. The standby processing device 300
includes processing devices 301 and 302. The processing
devices 301 and 302 of the standby processing device 300
25 perform identical computation processes, and when the
computation results match each other, the standby
processing device 300 controls the operation of the train
11 on the basis of the computation results.
[0016] As discussed above, the safety device 100
30 includes a plurality of processing devices 201, 202, 301,
and 302. Assume that the processing devices 201, 202, 301,
and 302 have similar configurations. The processing
devices 201, 202, 301, and 302 are central processing units
8
(CPUs), for example. The processing devices 201, 202, 301,
and 302 each include a database 1 for storing data
necessary for performing identical computation processes.
[0017] In the safety device 100, the processing devices
201, 202, 301, and 302 perform computation 5 processes
asynchronously and independently. As illustrated in FIG. 2,
the processing devices 201 and 202 obtain data necessary
for the operation of the train 11 from the traffic control
system 50 via the communication network 40 and the external
10 I/F device 71. Similarly, the processing devices 301 and
302 obtain data necessary for the operation of the train 11
from the traffic control system 50 via the communication
network 40 and the external I/F device 72. The processing
devices 201, 202, 301, and 302 of the safety device 100 can
15 receive data from the traffic control system 50 at
different timings because, for example, the processing
devices 201, 202, 301, and 302 perform computation
processes independently of each other, or the external I/F
devices 71 and 72 differ from each other in communication
20 condition.
[0018] FIG. 3 is a chart illustrating an example of the
timings at which the processing devices 201, 202, 301, and
302 receive data from the traffic control system 50 in the
safety device 100 according to the present embodiment. In
25 FIG. 3, vertically long rectangles represent data. As
illustrated in FIG. 3, the processing devices 201, 202, 301,
and 302 receive data at different timings. In such a
situation, in some cases, some processing devices
successfully receive data but others not. In other words,
30 the processing devices 201, 202, 301, and 302, which
perform identical computation processes, may hold different
pieces of date.
[0019] For example, if the data held in the processor
9
201 is different from that in the processor 202, the
computation results of the processing devices 201 and 202
can fail to match each other, with the result that the
active processing device 200 can fail to control the
operation of the train 11. If the 5 data held in the
processor 301 is different from that in the processor 302,
the computation results of the processing devices 301 and
302 can fail to match each other, with the result that the
standby processing device 300 can fail to control the
10 operation of the train 11 in the event of a breakdown of
the active processing device 200. If the data held in the
processing devices 201 and 202 is different from that in
the processing devices 301 and 302, the standby processing
device 300 holding the different data from that held by the
15 active processing device 200 provides the different
computation result from that provided by the active
processing device 200, which can be a source of accident in
the event that the processing device to control the train
11 is switched from active processing device 200 to the
20 standby processing device 300.
[0020] In the present embodiment, each processing device
of the safety device 100 manages the states of data held by
the processing devices 201, 202, 301, and 302, and a
predetermined one of the processing devices requests data
25 from the traffic control system 50. This makes it less
likely or unlikely to result in the situation where the
data held by one of the processing devices 201, 202, 301,
and 302 of the safety device 100 differs from that held in
the others.
30 [0021] Because the processing devices 201, 202, 301, and
302 have similar configurations as described above, the
configuration and the operations thereof will be described
with reference to the processor 201 as an example. FIG. 4
10
is a block diagram illustrating an example of a
configuration of the processor 201 included in the safety
device 100 according to the present embodiment. In FIG. 4,
the illustration of the processing devices 202, 301, and
302 is simplified. The processing device 5 201 includes the
database 1, a communication unit 2, a state managing unit 3,
a request managing unit 4, an obtainment managing unit 7,
and a computation unit 8. The request managing unit 4
includes a priority calculating unit 5, and a request
10 sorting unit 6.
[0022] The database 1 is a storage unit that stores data
necessary for the computation unit 8 to perform computation
processes. Data obtained from the traffic control system
50 is added to the database 1. The data stored in the
15 database 1 are updated with data obtained from the traffic
control system 50.
[0023] The communication unit 2 obtains data from the
traffic control system 50 via the communication network 40
and the external I/F device 71. The communication unit 2
20 outputs the obtained data to the obtainment managing unit 7.
The communication unit 2 obtains data version information
from the traffic control system 50 via the communication
network 40 and the external I/F device 71. The data
version information indicates the latest version of data
25 stored in the database 1. The communication unit 2 outputs
the obtained data version information to the state managing
unit 3. Under the control of the request managing unit 4,
the communication unit 2 requests data from the traffic
control system 50 via the external I/F device 71 and the
30 communication network 40.
[0024] The communication unit 2 also obtains, from the
request managing unit 4, a first request queue generated by
the request managing unit 4, and transmit the first request
11
queue to the other processing devices. The first request
queue generated by the request managing unit 4 will be
described later. The communication unit 2 obtains, from
the other processing devices, first request queues
generated by the other processing 5 devices. The
communication unit 2 outputs the obtained first request
queues to the request managing unit 4. Alternatively, the
communication unit 2 may be configured to have separate
functions, such as a transmission unit that performs
10 transmission processes and a reception unit that performs
reception processes.
[0025] The state managing unit 3 manages data stored in
the database 1. More specifically, the state managing unit
3 manages, on a data-unit by data-unit basis, whether or
15 not the version of the data stored in the database 1 is the
same as the latest version indicated by the data version
information obtained from the traffic control system 50
that is an external system. FIG. 5 is a table illustrating
an example of version management information held by the
20 state managing unit 3 in the processing device 201
according to the present embodiment. The version
management information illustrated in FIG. 5 indicates that,
among the data stored in the database 1, the data
identified by the name “data unit 1” is of the latest
25 version, the data identified by the name “data unit 2” is
not of the latest version, the data identified by the name
“data unit 3” is of the latest version, and it is unclear
whether or not data identified by the name “data unit 4” is
of the latest version. The state managing unit 3 outputs
30 the version management information illustrated in FIG. 5 to
the request managing unit 4.
[0026] The request managing unit 4 generates the first
request queue on the basis of the management state of data
12
in the state managing unit 3 and a type of predetermined
event that requires data in a case where the predetermined
event has occurred. The first request queue indicates data
to be requested from the traffic control system 50 and the
order in which the data is to be requested. 5 Among the data
managed in the state managing unit 3, the request managing
unit 4 identifies the data of not the same version as the
latest version, as the data to request from the traffic
control system 50. The case where a predetermined event
10 that requires data has occurred is, for example, a case
where the train 11 with the safety device 100 installed
therein travels within a travel section and reaches a point
a predetermined distance before a switching point between
that travel section and the next travel section. Data
15 required in the case where a predetermined event has
occurred is, for example, data necessary for the train to
travel within the next section, such as a speed limit set
at each point within the next travel section. The request
managing unit 4 outputs the generated first request queue
20 to the other processing devices via the communication unit
2.
[0027] In addition, the request managing unit 4 obtains,
from the other processing devices, first request queues
generated by the other processing devices. The first
25 request queues generated by the other processing devices
are first request queues generated by the request managing
units 4 of the other processing devices on the basis of the
management states of data in the state managing units 3 of
the other processing devices and types of predetermined
30 events that require data in cases where the predetermined
events have occurred. The request managing unit 4 combines
the generated first request queue with the obtained first
request queues to generate a second request queue
13
indicating data to be requested from the traffic control
system 50 by the safety device 100 and the order in which
the data are to be requested. The request managing unit 4
is capable of requesting data from the traffic control
system 50 via the communication unit 2, 5 the external I/F
device 71, and the communication network 40 by using the
second request queue.
[0028] Among the processing devices of the safety device
100 that currently control the train 11 is a processing
10 device for channel 1. The request managing unit 4 of this
processing device for channel 1, for example, requests data
from the traffic control system 50 via the communication
unit 2, the external I/F device, and the communication
network 40 by using the second request queue. Specifically,
15 during normal operation, the request managing unit 4 of the
processing device 201 for channel 1 of the active
processing device 200 request data from the traffic control
system 50 via the communication unit 2, the external I/F
device 71, and the communication network 40 by the second
20 request queue. When the active processing device 200 fails
to operate normally because of, for example, the breakdown,
the request managing unit 4 of the processing device 301
for channel 1 of the standby processing device 300 requests
data from the traffic control system 50 via the
25 communication unit 2, the external I/F device 72, and the
communication network 40 by using the second request queue.
[0029] In the safety device 100, the request managing
unit 4 of a predetermined one of the processing devices
requests data from the traffic control system 50 by using
30 the second request queue. In the safety device 100, that
is, a single processing device alone requests data from the
traffic control system 50. Thus, the safety device 100 can
prevent communication traffic between the safety device 100
14
and the traffic control system 50 from increasing as
compared with a case where a plurality of processing
devices request data from the traffic control system 50.
[0030] When the request managing unit 4 generates a
first request queue, the priority 5 calculating unit 5
determines, on the basis of the reason for request, the
order in which data is to be requested from the traffic
control system 50. The reason for request is the reason
for which data is to be requested from the traffic control
10 system 50. The priority calculating unit 5 holds a request
reason priority table in which the priorities of individual
reasons for request are set in advance, for example. The
priority calculating unit 5 determines, on the basis of the
request reason priority table, the order in which data are
15 to be requested from the traffic control system 50.
[0031] When the request managing unit 4 generates a
second request queue, the priority calculating unit 5
determines, on the basis of the reasons for request and the
priorities of the individual processing devices, the order
20 in which data is to be requested from the traffic control
system 50. The reasons for request are the reasons for
which data is to be requested from the traffic control
system 50. Note that, when the processing device to
control the train 11 is changed in the safety device 100,
25 the priorities of the processing devices are changed. For
example, when the processing device to control the train 11
is switched from the active processing device 200 to the
standby processing device 300, the priorities of the
processing devices are changed. In this case, when the
30 request managing unit 4 generates a second request queue,
the priority calculating unit 5 determines the order in
which data is to be requested from the traffic control
system 50, on the basis of the reasons for request, that is,
15
the reasons for which data is to be requested from the
traffic control system 50, and the changed priorities of
the individual processing devices. The priorities of the
processing devices may be changed by the request managing
unit 4 or the computation unit 8 that practically 5 controls
the operation of the train 11.
[0032] The priority calculating unit 5 holds the request
reason priority table described above, and a processingdevice
priority table, for example. In the processing10
device priority table, the priorities of the individual
processing devices are set in advance. The priority
calculating unit 5 determines the order in which data are
to be requested from the traffic control system 50, on the
basis of the request reason priority table and the
15 processing-device priority table. When the active
processing device 200 controls the operation, for example,
the processing-device priority table sets the priorities of
the processing device or 201 for channel 1 of the active
processing device 200, the processing device 202 for
20 channel 2 of the active processing device 200, the
processing device 301 for channel 1 of the standby
processing device 300, and the processing device 302 for
channel 2 of the standby processing device 300 in
descending order. The processor priority table may be
25 dynamically changed depending on the operation state of the
safety device 100. When the standby processing device 300
controls the operation, for example, the processing-device
priority table sets the priorities of the processing device
301 for channel 1 of the standby processing device 300, the
30 processing device 302 for channel 2 of the standby
processing device 300, the processing device 201 for
channel 1 of the active processing device 200, the
processing device 202 for channel 2 of the active
16
processing device 200 in descending order.
[0033] The request sorting unit 6 generates the abovedescribed
first request queue by sorting records describing
information on individual data in the order of request
within a request queue on the basis of 5 the order in which
the data is to be requested from the traffic control system
50 determined by the priority calculating unit 5. In
addition, the request sorting unit 6 generates the abovedescribed
second request queue by sorting records
10 describing information on individual data in the order of
request within a request queue on the basis of the order in
which the data are to be requested from the traffic control
system 50 determined by the priority calculating unit 5.
Assume that the “request queue” without the prefix “first”
15 or “second” has records unsorted.
[0034] FIG. 6 is a table illustrating an example of the
second request queue generated by the request managing unit
4 of the processor 201 according to the present embodiment.
The second request queue illustrated in FIG. 6 has records
20 sorted by the request sorting unit 6. The first row in FIG.
6 corresponds to records describing information on
requested data. In FIG. 6, a request ID represents
identification information for identifying individual data.
In FIG. 6, a reason for request represents the reason for
25 which data is to be requested from the traffic control
system 50. In FIG. 6, a requesting processing device
represents the processing device that has determined to
request, from the traffic control system 50, data
identified the request ID. In FIG. 6, the active
30 processing device 200 is represented by System-A, and the
standby processing device 300 is represented by System-B.
In FIG. 6, a state indicates whether or not data is
requested from the traffic control system 50. Note that
17
the first request queue generated by the request managing
unit 4 has a structure similar to the second request queue
illustrated in FIG. 6. In the case of the first request
queue, the processing that generates the first request
queue is shown under the item “requesting 5 processing
device”.
[0035] The obtainment managing unit 7 obtains data from
the traffic control system 50 via the communication network
40, the external I/F device 71, and the communication unit
10 2. When the same data as the obtained data is not present
in the database 1, the obtainment managing unit 7 stores
the obtained data in the database 1. When data of the same
kind as, but in a different version from, the obtained data
is stored in the database 1, the obtainment managing unit 7
15 updates the data stored in the database 1 with the obtained
data. In addition, the obtainment managing unit 7 manages
the state of obtainment of data from the traffic control
system 50. Specifically, the obtainment managing unit 7
manages whether or not the data indicated in the second
20 request queue is requested from the traffic control system
50 and whether or not the data is obtained from the traffic
control system 50.
[0036] FIG. 7 is a table illustrating an example of data
obtainment management information held by the obtainment
25 managing unit 7 of the processor 201 according to the
present embodiment. In FIG. 7, a request ID represents
identification information for identifying data to be
requested from the traffic control system 50. Note that,
as illustrated in FIG. 7, when the data size is large, the
30 data is divided into a plurality of pieces of data, each of
the pieces of data obtained by the division is used as a
data unit to be requested from the traffic control system
50, and identification information is assigned to each data
18
unit. In FIG. 7, the item “request” indicates whether or
not data is requested from the traffic control system 50.
In FIG. 7, the item “receive” indicates whether or not data
is obtained from the traffic control system 50.
[0037] The computation unit 8 performs 5 computation
processes by using data stored in the database 1, and
controls the operation of the train 11 by using the
computation results.
[0038] Next, a process of requesting data from the
10 traffic control system 50 by the processor 201 in the
safety device 100 will be explained. FIG. 8 is a first
flowchart illustrating a process of requesting data from
the traffic control system 50 by the processor 201 in the
safety device 100 according to the present embodiment. FIG.
15 9 is a second flowchart illustrating the process of
requesting data from the traffic control system 50 by the
processor 201 in the safety device 100 according to the
present embodiment. FIG. 10 is a third flowchart
illustrating the process of requesting data from the
20 traffic control system 50 by the processor 201 in the
safety device 100 according to the present embodiment.
[0039] In the processor 201, the state managing unit 3
checks whether or not data version information indicating
the latest version of data stored in the database 1 is
25 obtained from the traffic control system 50 via the
communication network 40, the external I/F device 71, and
the communication unit 2 (step S1). If the data version
information is obtained (step S1: Yes), the state managing
unit 3 compares the version of each data indicated by the
30 data version information with the version of data stored in
the database 1. If data whose version is not the same as
the latest version, that is, data of not the same version
as the latest one is present (step S2: Yes), the state
19
managing unit 3 outputs, to the request managing unit 4,
the identification information on data whose version is not
the same as the latest version, information that the
version is not the same as the latest version, which is the
reason for requesting data, and 5 the identification
information on the processor 201. The request managing
unit 4 registers a record in a request queue (step S3).
This record registered in the request queue indicates that
the identification information on the data of not the same
10 version is “request ID”, being not the same version is
“reason for request”, the identification information on the
processor 201 is “requesting processor”, and the “waiting”
is “state”. The term “waiting” means waiting to be
requested. If the state managing unit 3 has not obtained
15 the data version information (step S1: No), the processing
device 201 skips the processes in steps S2 and S3, and if
data of not the same version as the latest version is not
present in the state managing unit 3 (step S2: No), the
processor 201 skips the process in step S3.
20 [0040] The state managing unit 3 checks whether or not a
predetermined event has occurred in the train 11 (step S4).
If a predetermined event has occurred (step S4: Yes), the
state managing unit 3 outputs, to the request managing unit
4, the identification information on data necessary when a
25 predetermined event has occurred, the identification
information on the occurred event, that is, the
predetermined event, which is the reason for requesting
data, and the identification information on the processor
201. The request managing unit 4 registers a record in the
30 request queue (step S5). The record registered in step 5
indicates that the identification information on the data
necessary when the predetermined event has occurred is
“request ID”, the identification information on the
20
predetermined event is “reason for request”, the
identification information on the processor 201 is
“requesting processor”, and “waiting” is “state”. The term
“waiting” means waiting to be requested. If no
predetermined event has occurred 5 (step S4: No), the
processing device 201 skips the process in step S5.
[0041] The request managing unit 4 checks whether or not
there is some overlap in the data to be requested, that is,
whether or not records with the same request ID are present
10 in the request queue (step S6). If records with the same
request ID are present in the request queue (step S6: Yes),
the request managing unit 4 deletes, from the records with
the same request ID, records other than the record with the
highest priority, leaving this record with the highest
15 priority on the basis of the request reason priority table
(step S7). If there are no records with the same request
ID in the request queue (step S6: No), the request managing
unit 4 skips the process in step S7. The request managing
unit 4 sorts the records registered in the request queue in
20 descending order of the priority on the basis of the
request reason priority table (step S8). The request queue
having the records sorted in descending order of the
priority is the first request queue described above. The
request managing unit 4 transmits the generated first
25 request queue to the other processing devices via the
communication unit 2 (step S9).
[0042] The request managing unit 4 checks whether or not
a first request queue generated by another processing
device is received from the other processing device via the
30 communication unit 2 (step S10). If a first request queue
generated by another processing device is received from the
other processing device (step S10: Yes), the request
managing unit 4 checks whether or not records that are not
21
present in the generated first request queue are present in
the first request queue obtained from the processing device
(step S11). If records that are not present in the
generated first request queue are present in the first
request queue obtained from the processing 5 device (step
S11: Yes), the request managing unit 4 adds the
corresponding records to the generated first request queue
(step S12). In other words, the request managing unit 4
combines the generated first request queue with the first
10 request queue obtained from the processing device. If a
first request queue generated by another processing device
is not received from the other processing device (step S10:
No), the request managing unit 4 skips the processes in
steps S11 and S12, and if records that are not present in
15 the generated first request queue are not present in the
first request queue obtained from the processing device
(step S11: No), the request managing unit 4 skips the
process in step S12.
[0043] The request managing unit 4 sorts the records
20 registered in the request queue after the process in step
S12 in descending order of the priority on the basis of the
request reason priority table and the processing-device
priority table (step S13). The request queue having the
records sorted in descending order of the priority is the
25 second request queue described above. The request managing
unit 4 outputs the generated second request queue to the
obtainment managing unit 7. The obtainment managing unit 7
generates data obtainment management information on the
basis of the second request queue. Note that the request
30 managing unit 4 uses the generated first request queue in
generating the second request queue, and holds the
generated first request queue by, for example, copying the
generated first request queue even after the second request
22
queue is generated.
[0044] The obtainment managing unit 7 checks whether or
not data is obtained from the traffic control system 50 via
the communication network 40, the external I/F device 71,
and the communication unit 2 (step 5 S14). If data is
obtained from the traffic control system 50 (step S14: Yes),
and when the corresponding data are present in the data
obtainment management information, the obtainment managing
unit 7 takes the corresponding data as “received” in the
10 field “receive”. In addition, the obtainment managing unit
7 outputs the identification information on the obtained
data to the request managing unit 4. Upon obtaining the
identification information on the obtained data from the
obtainment managing unit 7, the request managing unit 4
15 check whether or not a record of data with the request ID
corresponding to the identification information on the
obtained data is present in the first request queue (step
S15). If the record of data with the request ID
corresponding to the identification information on the
20 obtained data is present in the first request queue (step
S15: Yes), the obtainment of the data is completed, after
which the request managing unit 4 of the processing device
201 changes the records of data with the corresponding
request ID in the first request queue and the second
25 request queue such that the state of the record indicating
the processor 201 as the requesting processing device is
changed to “complete” (step S16). If data is not obtained
from the traffic control system 50 (step S14: No), the
processing device 201 skips the processes in steps S15 and
30 S16, and if no record of data with the request ID
corresponding to the identification information of the
obtained data is present (step S15: No), the processing
device 201 skips the process in step S16.
23
[0045] The request managing unit 4 obtains a first
request queue generated by another processing device from
the other processing device via the communication unit 2,
and checks whether or not a record with the state being
“complete” is present in the obtained first 5 request queue
(step S17). If the record with the state being “complete”
is present in the obtained first request queue (step S17:
Yes), the request managing unit 4 updates the state of the
corresponding record in the second request queue to
10 “complete” (step S18). If no record with the state being
“complete” is present in the obtained first request queue
(step S17: No), the request managing unit 4 skips the
process in step S18.
[0046] The request managing unit 4 checks whether or not
15 a plurality of records with the same request ID are present
in the second request queue, the state of some of which
being “requesting”, and a predetermined time has passed in
this state (step S19). If the predetermined time has
passed (step S19: Yes), the request managing unit 4
20 requests the data from the traffic control system 50 again
(step S20). Note that, in step S20, only the request
managing unit 4 of the predetermined processing device
practically requests the data from the traffic control
system 50 again. The request managing units 4 of the other
25 processing devices do not request the data from the traffic
control system 50 again.
[0047] If the predetermined time has not passed (step
S19: No), and if the states of all the records with the
same request ID are “complete” in the second request queue,
30 the request managing unit 4 deletes the corresponding
records (step S21). If no records with the state being
“requesting” are present, that is, if the states of all the
records are “waiting” in the second request queue, the
24
request managing unit 4 requests data with the request ID
of the record at the top of the second request queue from
the traffic control system 50, and changes the state of the
corresponding record to “requesting” (step S22). In a
manner similar to step S20, only the request 5 managing unit
4 of the predetermined processing device practically
requests the data from the traffic control system 50 in
step S22. The request managing units 4 of the other
processing devices do not request the data from the traffic
10 control system 50.
[0048] In the safety device 100, each of the processing
devices repeats the processes in the flowcharts illustrated
in FIGS. 8 to 10. In this manner, each of the processing
devices can update the second request queue into the latest
15 state.
[0049] The request managing unit 4 of the processing
device generates a first request queue, obtains first
request queues generated by the other processing device
from the other processing devices, and combines the
20 generated first request queue with the obtained first
request queues to generate a second request queue. It is
noted that the second request queue may be generated in
other manners. Although generating a first request queue,
the request managing unit 4 of each of the processing
25 devices does not request data from the traffic control
system 50 by using the first request queue. Thus, records
in the first request queues need not be sorted on the basis
of the priority of the reason for request.
[0050] The request managing unit 4 of the processing
30 device can determine the data to request from the traffic
control system 50, and the order in which data are to be
requested from the traffic control system 50, on the basis
of the management states of data in the state managing unit
25
3 of that processing device, a type of predetermined event
that requires data in a case where the predetermined event
has occurred in that processor, the management states of
data in the state managing units 3 of the other processing
devices, and the types of events that require 5 data in cases
where the predetermined events have occurred in the other
processing devices. The request managing unit 4 can
generate a second request queue by determining data to
request from the traffic control system 50 and the order in
10 which the data is to be requested from the traffic control
system 50.
[0051] Specifically, the request managing unit 4 can
determine data to request from the traffic control system
50 and the order in which the data is to be requested from
15 the traffic control system 50 on the basis of the
management states of data in the state managing unit 3, the
management states of data in the state managing units 3 of
the other processing devices, a type of predetermined event
that requires data in a case where the predetermined event
20 has occurred. In this case, the request managing unit 4 of
the processing device identifies, as the data to request
from the traffic control system 50, the data of not the
same version as the latest version, among the data managed
in the state managing unit 3 of that processing device and
25 the state managing units 3 of the other processing devices.
In this manner, the request managing unit 4 can generate a
second request queue when information necessary for
generating a first request queue is present instead of the
state of the first request queue. In this case, the safety
30 device 100 can reduce the processing loads on the
processing devices in sorting records for generating first
request queues. The request managing unit 4 combines the
generated first request queue with the obtained first
26
request queues to generate the second request queue in the
embodiment, which processing is similar, in view of the
information used, to that in the case of determining data
to request from the traffic control system 50 and the order
in which the data is to be requested 5 from the traffic
control system 50 on the basis of the management states of
data in the state managing unit 3, the management states of
data in the state managing units 3 of the other processing
devices, and the types of predetermined events that require
10 data in cases where the predetermined events have occurred.
[0052] Next, a hardware configuration of the safety
device 100 will be described. In the safety device 100,
while the processing devices 201, 202, 301, and 302 are
CPUs as described above, the processing devices 201, 202,
15 301, and 302 each may alternatively be implemented by
processing circuitry. The processing circuitry may be
constituted by a processor that executes programs stored in
a memory and the memory, or may be dedicated hardware.
[0053] FIG. 11 is a diagram illustrating an example of a
20 case where the processing circuitry included in the safety
device 100 according to the present embodiment is
implemented by a processor and a memory. In the case where
the processing circuitry is constituted by the processor 91
and the memory 92, the functions of the processing
25 circuitry of the safety device 100 are implemented by
software, firmware, or a combination of software and
firmware. The software or firmware is described in the
form of programs and stored in the memory 92. The
processing circuitry implements the functions by reading
30 and executing the programs stored in the memory 92 by the
processor 91. Specifically, the processing circuitry
includes the memory 92 for storing programs that results in
execution of processes of the safety device 100. In other
27
words, these programs cause a computer to execute the
procedures and the methods of the safety device 100.
[0054] Note that the processor 91 may be a CPU, a
processing device, a computing device, a microprocessor, a
microcomputer, a digital signal processor 5 (DSP), or the
like. In addition, the memory 92 is a nonvolatile or
volatile semiconductor memory such as a random access
memory (RAM), a read only memory (ROM), a flash memory, an
erasable programmable ROM (EPROM), or an electrically EPROM
10 (EEPROM: registered trademark), a magnetic disk, a flexible
disk, an optical disk, a compact disc, a mini disc, a
digital versatile disc (DVD) or the like, for example.
[0055] FIG. 12 is a diagram illustrating an example of a
case where the processing circuitry included in the safety
15 device 100 according to the present embodiment is
constituted by dedicated hardware. In the case where the
processing circuitry is constituted by dedicated hardware,
the processing circuitry 93 illustrated in FIG. 12 is a
single circuit, a composite circuit, a programmed processor,
20 a parallel-programmed processor, an application specific
integrated circuit (ASIC), a field programmable gate array
(FPGA), or a combination thereof, for example. The
functions of the safety device 100 may be implemented
separately by the processing circuitry 93, or may be
25 implemented collectively by the processing circuitry 93.
[0056] Note that some of the functions of the safety
device 100 may be implemented by dedicated hardware, and
others may be implemented by software or firmware. As
described above, the processing circuitry is capable of
30 implementing the above-described functions by dedicated
hardware, software, firmware, or a combination thereof.
[0057] As described above, according to the present
embodiment, in the train control system 60, the safety
28
device 100 includes a plurality of processors, each of the
processors determines data to request from the traffic
control system 50 and the order in which the data are to be
requested, and one of the processors requests data from the
traffic control system 50. As a result, 5 the safety device
100, when including a plurality of processors, can reduce
differences between data stored in the databases of the
processors.
[0058] In addition, the safety device 100 request data
10 in descending order of priority. As a result, the safety
device 100 can update necessary data and obtain necessary
data while reducing the influence on the control of the
operation of the train 11. In addition, the safety device
100 repeats the process of generating the second request
15 queue. As a result, the safety device 100 can update the
second request queue with the latest state.
[0059] While the case where the safety device 100
including a plurality of processors requests and obtains
data from the traffic control system 50 in the train
20 control system 60 has been described in the present
embodiment, this is an example, and a data control system
may be used instead of the traffic control system 50. This
is also applicable to other uses. For example, this is
also applicable to a system including autonomous driving
25 vehicles, which are automobiles that automatically operate,
and a control device for transmitting data to the
autonomous driving vehicles in a case where each autonomous
driving vehicle requests and obtains necessary data from
the control device. In this case, a device that requests
30 data in each autonomous driving vehicle corresponds to the
terminal device, and the control device that transmits data
to each autonomous driving vehicle corresponds to the
external system.
29
[0060] The configurations presented in the embodiment
above are examples of the present invention, and can be
combined with other known technologies or can be partly
omitted or modified without departing from the scope of the
5 present invention.
Reference Signs List
[0061] 1, 51 database; 2 communication unit; 3 state
managing unit; 4 request managing unit; 5 priority
10 calculating unit; 6 request sorting unit; 7 obtainment
managing unit; 8 computation unit; 10 A Company group; 11,
12, 13, 21, 31, 32 train; 20 B Company group; 30 C
Company group; 40 communication network; 50 traffic
control system; 60 train control system; 71, 72 external
15 I/F device; 100 safety device; 200 active processing
device; 201, 202, 301, 302 processor; 300 standby
processing device.
30
We Claim :
1. A terminal device comprising a plurality of processing
devices, wherein the processing devices each includes:
a database;
a state managing unit to manage 5 data stored in the
database;
a request managing unit to determine data to request
from an external system and an order in which the data is
to be requested from the external system on the basis of a
10 management state of the data in the state managing unit, a
management state of data in a state managing unit of
another processing device, and a type of predetermined
event requiring data in a case where the predetermined
event has occurred, the request managing unit being capable
15 of requesting data from the external system on the basis of
the order; and
an obtainment managing unit to manage a state of
obtainment of data from the external system, and
a request managing unit of a predetermined processing
20 device requests data from the external system.
2. The terminal device according to claim 1, wherein
the state managing unit manages, on a data-unit by
data-unit basis, whether or not a version of data stored in
25 the database is the same as a latest version of data stored
in the database, the latest version being indicated by
data version information obtained from the external system,
and
the request managing unit identifies, as data to be
30 requested from the external system, data of not the same
version as the latest version among data managed by the
state managing unit and a state managing unit of another
processing device.
31
3. The terminal device according to claim 1 or 2, wherein
the request managing unit generates a first request
queue indicating the data to request from the external
system and the order in which the data 5 is to be requested
on the basis of the management state of the data in the
state managing unit and the type of predetermined event,
the request management unit obtains, from another
processing device, a first request queue generated on the
10 basis of a management state of data in the other processing
device and a type of predetermined event requiring data in
a case where the predetermined event has occurred, and
the request management unit combines the generated
first request queue with the obtained first request queue
15 to generate a second request queue indicating data to
request from the external system and an order in which the
data is to be requested by the terminal device, and
the request managing unit of the predetermined
processing device requests data from the external system by
20 using the second request queue.
4. The terminal device according to claim 3, wherein
the request managing unit generates the first request
queue by determining the order in which the data is to be
25 requested from the external system on the basis of
priorities of reasons for requesting data, and sorting
records describing information on the individual data in
the order of the request, and
the request managing unit further generates the second
30 request queue by determining the order in which data is to
be requested from the external system on the basis of the
priorities of the reasons for requesting data and
priorities of the individual processing devices, and
32
sorting records describing information on the individual
data in the order of the request.
5. The terminal device according to claim 4, wherein
when a processing device to control 5 the terminal
device is changed, the priorities of the individual
processing devices are changed, and
when the priorities of the individual processing
devices are changed, the request managing unit generates
10 the second request queue by determining the order in which
data is to be requested from the external system on the
basis of the priorities of the reasons for requesting data
and the changed priorities of the individual processing
devices, and sorting records describing information on the
15 individual data in the order of the request.
6. The terminal device according to any one of claims 3
to 5, wherein
the obtainment managing unit manages whether or not
20 data indicated in the second request queue is requested
from the external system, and whether or not the data is
obtained from the external system.
7. A data management method for a terminal device
25 including a plurality of processing devices, the data
management method comprising in each of the processing
devices:
a first step of managing, by a state managing unit,
data stored in a database;
30 a second step of determining, by a request managing
unit, data to request from an external system and an order
in which the data is to be requested from the external
system on the basis of a management state of the data in
33
the state managing unit, a management state of data in a
state managing unit of another processing device, and a
type of predetermined event requiring data in a case where
the predetermined event has occurred; and
a third step of managing, by an obtainment 5 managing
unit, a state of obtainment of data from the external
system, wherein
a request managing unit of a predetermined processing
device requests data from the external system.
10
8. The data management method according to claim 7,
wherein
in the first step, the state managing unit manages, on
a data-unit by data-unit basis, whether or not a version of
15 data stored in the database is the same as a latest version
of data stored in the database, the latest version being
indicated by data version information obtained from the
external system, and
in the second step, the request managing unit
20 identifies, as data to be requested from the external
system, data of not the same version as the latest version
among data managed by the state managing unit and a state
managing unit of another processing device.
25 9. The data management method according to claim 7 or 8,
wherein
in the second step, the request managing unit
generates a first request queue indicating the data to
request from the external system and the order in which the
30 data is to be requested on the basis of the management
state of the data in the state managing unit and the type
of predetermined event, obtains, from another processing
device, a first request queue generated on the basis of a
34
management state of data in the other processing device and
a type of predetermined event requiring data in a case
where the predetermined event requiring data has occurred,
combines the generated first request queue with the
obtained first request queue to generate 5 a second request
queue indicating data to request from the external system
and an order in which the data is to be requested by the
terminal device, and
the request managing unit of the predetermined
10 processing device requests data from the external system by
using the second request queue.
10. The data management method according to claim 9,
wherein
15 in the second step, the request managing unit
generates the first request queue by determining the order
in which the data is to be requested from the external
system on the basis of priorities of reasons for requesting
data, and sorting records describing information on the
20 individual data in the order of the request, and further
generates the second request queue by determining the order
in which data is to be requested from the external system
on the basis of the priorities of the reasons for
requesting data and priorities of the individual processing
25 devices, and sorting records describing information on the
individual data in the order of the request.
11. The data management method according to claim 10,
wherein
30 when a processing device to control the terminal
device is changed, the priorities of the individual
processing devices are changed, and
in the second step, when the priorities of the
35
individual processing devices are changed, the request
managing unit generates the second request queue by
determining the order in which data is to be requested from
the external system on the basis of the priorities of the
reasons for requesting data and the changed 5 priorities of
the individual processing devices, and sorting records
describing information on the individual data in the order
of the request.
10 12. The data management method according to any one of
claims 9 to 11, wherein
in the third step, the obtainment managing unit
manages whether or not data indicated in the second request
queue is requested from the external system, and whether or
15 not the data is obtained from the external system.