FORM 2 THE PATENTS ACT, 1970
(39 of& 1970) THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
DISTRIBUTION DEVICE, RECEIVING DEVICE, DATA DISTRIBUTION
SYSTEM, AND DATA DISTRIBUTION 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 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED;
2
DESCRIPTION
Field
[0001] The present invention relates to a distribution
5 device for distributing data, a receiving device, a data
distribution system, and a data distribution method.
Background
[0002] There has been a system that collects data
10 continuously generated and analyzes the data in real time
using the collected data. A distribution device that
collects the data from a data source distributes necessary
data to a receiving device that performs the data analysis.
An increase in the number of receiving devices to which the
15 data is distributed results in a delay in distributing the
data from the distribution device due to factors caused by
an increase in the amount of data to be distributed, the
factors including an increase in the processing load and an
increase in the bandwidth used by a network used for the
20 data distribution.
[0003] Patent Literature 1 discloses a technique in
which a stream data processing system that is a data
distribution device transmits difference information
between the latest data and previous data, and a client
25 computer that is a data receiving device restores the
latest data using the previous data and the difference
information newly acquired. In Patent Literature 1,
assuming that the latest data and the previous data have
similar values, the amount of data to be distributed is
30 reduced by transmitting the difference information instead
of the data itself.
Citation List
3
Patent Literature
[0004] Patent Literature 1: Japanese Patent Application
Laid-open No. 2009-134689
5 Summary
Technical Problem
[0005] Also, in a train, a sensor measures a state of
equipment mounted on the train, and a vehicle information
management device collects the measured value measured by
10 the sensor as continuously generated data for use in data
analysis. However, when the technique of Patent Literature
1 is applied to a train, a difference between previous data
and the latest data may be large depending on the travel
route of the train. For example, on a curve, uphill,
15 downhill, or the like, the brake air pressure or the like
changes greatly with time, so that data of a measured item
such as the brake air pressure more often has a large
difference between the previous data and the latest data.
Therefore, an increase in the amount of data to be
20 distributed has resulted in a delay in distributing the
data from the distribution device due to factors such as an
increase in the processing load and an increase in the
bandwidth used by a network.
[0006] The present invention has been made in view of
25 the above, and an object of the present invention is to
provide a distribution device that can reduce an amount of
data when distributing data indicating a state of equipment
mounted on a train.
30 Solution to Problem
[0007] In order to solve the above problem and achieve
the object, the distribution device according to an aspect
of the present invention includes a data acquisition unit
4
to acquire operation data from a vehicle information
management device that collects a measured value indicating
an operating state of equipment mounted on a train, the
operation data including position information indicating a
5 position of the train when the measured value is acquired
and information on the measured value. The distribution
device further includes a history data management unit to
determine a representative value for each position
information, generate history data including the position
10 information and information on the representative value,
store the history data, and distribute the history data to
a receiving device. The distribution device further
includes a connection management unit to read, on a basis
of the position information included in the operation data,
15 the representative value corresponding to the position
information from the history data, calculate a difference
value that is a difference between the measured value
included in the operation data and the representative value,
and distribute difference data including the position
20 information and information on the difference value to the
receiving device.
Advantageous Effects of Invention
[0008] According to the present invention, the
25 distribution device has an effect of being able to reduce
the amount of data when distributing the data indicating
the state of the equipment mounted on the train.
Brief Description of Drawings
30 [0009] FIG. 1 is a diagram illustrating an example of
the configuration of a data distribution system according
to a first embodiment.
FIG. 2 is a block diagram illustrating an example of
5
the configuration of a data distribution device according
to the first embodiment.
FIG. 3 is a table illustrating an example of history
data stored in a history data storage unit according to the
5 first embodiment.
FIG. 4 is a block diagram illustrating an example of
the configuration of a data receiving device according to
the first embodiment.
FIG. 5 is a flowchart illustrating processing in which
10 the data distribution device and the data receiving device
synchronize the history data in the data distribution
system according to the first embodiment.
FIG. 6 is a flowchart illustrating processing in which
the data distribution device stores the history data in the
15 data distribution system according to the first embodiment.
FIG. 7 is a flowchart illustrating processing in which
the data distribution device distributes difference data in
the data distribution system according to the first
embodiment.
20 FIG. 8 is a diagram illustrating an example of a case
where a processing circuit of the data distribution device
according to the first embodiment includes a processor and
a memory.
FIG. 9 is a diagram illustrating an example of a case
25 where the processing circuit of the data distribution
device according to the first embodiment includes dedicated
hardware.
Description of Embodiments
30 [0010] A distribution device, a receiving device, a data
distribution system, and a data distribution method
according to embodiments of the present invention will now
be described in detail with reference to the drawings.
6
Note that the present invention is not limited to the
embodiments.
[0011] First Embodiment.
FIG. 1 is a diagram illustrating an example of the
5 configuration of a data distribution system 10 according to
a first embodiment of the present invention. The data
distribution system 10 is a system mounted on a train 100.
The data distribution system 10 includes a vehicle
information management device 1, a data distribution device
10 2, and data receiving devices 3-1 to 3-4.
[0012] The vehicle information management device 1
collects, from on-board equipment (not shown) mounted on
the train 100, a measured value indicating an operating
state of the on-board equipment. The on-board equipment is,
15 for example, equipment such as a motor for driving wheels,
a brake, an air conditioner, a door, or the like. A
plurality of pieces of the on-board equipment are mounted
on the train 100. The measured value indicating the
operating state of the on-board equipment is a value
20 measured by a sensor (not shown) or the like, and is, for
example, an air pressure value of the air used for an air
brake when the on-board equipment is the air brake. The
measured value indicating the operating state of the onboard
equipment is stream data that is periodically
25 collected by the vehicle information management device 1.
Moreover, the vehicle information management device 1
periodically acquires position information of the train 100.
The position information is indicated by kilometrage from a
point serving as a starting point. The position
30 information also includes information on the direction of
travel on a line on which the train 100 operates. The
information on the direction of travel is, for example,
information such as an up line or a down line. The vehicle
7
information management device 1 distributes, as operation
data, the position information indicating the position of
the train 100 when a measured value is acquired,
information on a measured item corresponding to the
5 measured value, and information on the measured value to
the data distribution device 2. The vehicle information
management device 1 periodically distributes the operation
data to the data distribution device 2 during the operation
of the train 100. Note that the vehicle information
10 management device 1 may include, in the operation data,
other information such as time information when the
measured value is acquired.
[0013] The data distribution device 2 is a distribution
device that acquires the operation data from the vehicle
15 information management device 1 and distributes, on the
basis of a distribution request acquired from the data
receiving devices 3-1 to 3-4, information on a measured
value of a measured item specified in the distribution
request to the data receiving devices 3-1 to 3-4. The data
20 distribution device 2 distributes, to the data receiving
devices 3-1 to 3-4, difference data of the information on
the measured value of the measured item specified in the
distribution request among the operation data received from
the vehicle information management device 1. The
25 difference data has a small amount of data as compared to a
case where the information on the measured value is
distributed as is. Details of the difference data will be
described later. The data distribution device 2
periodically distributes the difference data to the data
30 receiving devices 3-1 to 3-4 during the operation of the
train 100. The data distribution device 2 also distributes
history data to the data receiving devices 3-1 to 3-4 after
the start of the train 100 and before distributing the
8
difference data. The history data is data required for the
data receiving devices 3-1 to 3-4 to restore the measured
value using the difference data. Note that the data
distribution device 2 may distribute the history data to
5 the data receiving devices 3-1 to 3-4 after the data
distribution device 2 and the data receiving devices 3-1 to
3-4 are all started.
[0014] The data receiving devices 3-1 to 3-4 are
receiving devices that make the distribution request to the
10 data distribution device 2 and periodically acquire the
difference data of the measured item specified in the
distribution request during the operation of the train 100.
The data receiving devices 3-1 to 3-4 restore the measured
value collected by the vehicle information management
15 device 1 using the history data acquired from the data
distribution device 2 after the train 100 is started and
the difference data periodically distributed. Note that
the data receiving devices 3-1 to 3-4 are mounted on
different vehicles of the train 100 in FIG. 1 as an example,
20 but the data receiving devices 3-1 to 3-4 may be mounted on
the same vehicle. Moreover, the data distribution device 2
and the data receiving devices 3-1 to 3-4 may be connected
via a wired network or may be connected via a wireless
network. In the case where the data distribution device 2
25 and the data receiving devices 3-1 to 3-4 are connected via
a wireless network, the data receiving devices 3-1 to 3-4
may be located outside the train 100. The data receiving
devices 3-1 to 3-4 will be referred to as a data receiving
device 3 when not distinguished from one another.
30 [0015] Next, the configuration of the data distribution
device 2 will be described. FIG. 2 is a block diagram
illustrating an example of the configuration of the data
distribution device 2 according to the first embodiment.
9
The data distribution device 2 includes a data acquisition
unit 21 and a data distribution unit 22. The data
distribution unit 22 includes a connection management unit
23 and a history data management unit 27.
5 [0016] The data acquisition unit 21 acquires the
operation data from the vehicle information management
device 1. The data acquisition unit 21 duplicates the
operation data acquired and outputs the operation data to
the connection management unit 23 and the history data
10 management unit 27 of the data distribution unit 22.
[0017] On the basis of the distribution request acquired
from the data receiving device 3, the data distribution
unit 22 extracts the measured value of the measured item
specified in the distribution request from the operation
15 data acquired by the data acquisition unit 21. The data
distribution unit 22 generates the difference data on the
basis of the measured value of the measured item extracted,
and distributes the difference data to the data receiving
device 3. The data distribution unit 22 also distributes
20 the history data to the data receiving device 3 after the
start of the train 100 and before distributing the
difference data.
[0018] In the data distribution unit 22, the history
data management unit 27 includes a history data calculation
25 unit 28, a history data storage unit 29, and a history data
synchronization unit 30.
[0019] The history data calculation unit 28 uses the
operation data acquired from the data acquisition unit 21
to determine, for each measured item, a representative
30 value for each position information using measured values
of the operation data acquired at different times. The
measured values of the operation data acquired at different
times include, for example, a measured value of the latest
10
operation data and a measured value of the operation data
acquired in the past. The history data calculation unit 28
for example calculates, for each measured item, an average
value using the measured value of the latest operation data
5 and the measured value of the operation data acquired in
the past for each position information, and determines the
average value calculated to be the representative value.
The history data calculation unit 28 may determine a median
value of a plurality of measured values to be the
10 representative value. The following description relates to
the case where the representative value is the average
value. The history data calculation unit 28 causes the
history data storage unit 29 to store the position
information, information on the measured item, and
15 information on the average value as the history data. The
history data calculation unit 28 may store the operation
data acquired in the past in a built-in storage unit or in
the history data storage unit 29.
[0020] The history data storage unit 29 stores the
20 history data including the information on the average value
determined by the history data calculation unit 28. FIG. 3
is a table illustrating an example of the history data
stored in the history data storage unit 29 according to the
first embodiment. The history data illustrated in FIG. 3
25 indicates an average value calculated for each position
information regarding a certain measured item. In FIG. 3,
values represented by numerical values are the average
values. When a difference calculation unit 26 described
later searches the history data in the history data storage
30 unit 29, the position information serves as a key and the
numerical value, that is, the average value, serves as a
value. In the example of FIG. 3, a value representing the
position information is in meters, and the position
11
information is in increments of one meter. Moreover, in
the example of FIG. 3, in order to reduce the storage
capacity of the history data storage unit 29, the history
data calculation unit 28 treats ten meters of the position
5 information as one unit, calculates the average value of
the ten meters, and causes the history data storage unit 29
to store the average value. The history data storage unit
29 stores the history data similar to the table illustrated
in FIG. 3 for each measured item. Note that the history
10 data storage unit 29 may add a numerical value column on
the right side of the numerical value in the table
illustrated in FIG. 3, list values of average values
calculated for a different measured item in the column, and
store history data corresponding to a plurality of measured
15 items in the form of one table. As for the position
information, the history data calculation unit 28 may
calculate the history data for each meter instead of
putting together the plurality of pieces of position
information as illustrated in FIG. 3, and cause the history
20 data storage unit 29 to store the history data.
[0021] The history data synchronization unit 30
distributes the latest history data, which is stored in the
history data storage unit 29 at the time of start of the
train 100, to the data receiving device 3 after the start
25 of the train 100 and before the difference calculation unit
26 described later distributes the difference data. As a
result, the history data stored in the data distribution
device 2 and the data receiving device 3 can be
synchronized. That is, the data distribution device 2 and
30 the data receiving device 3 hold the history data of the
same contents.
[0022] In the data distribution unit 22, the connection
management unit 23 includes a request analysis unit 24, a
12
data extraction unit 25, and the difference calculation
unit 26.
[0023] The request analysis unit 24 analyzes the
distribution request, which is a request acquired from the
5 data receiving device 3, and determines the measured item
within the operation data to be distributed to the data
receiving device 3, from which the distribution request is
acquired, on the basis of the measured item specified in
the distribution request.
10 [0024] On the basis of the specification of the measured
item from the request analysis unit 24, the data extraction
unit 25 extracts the operation data for the measured item
specified from the operation data that is acquired from the
data acquisition unit 21.
15 [0025] On the basis of the position information and
information on the measured item included in the operation
data extracted by the data extraction unit 25, the
difference calculation unit 26 reads the average value
corresponding to the same position information for each
20 measured item from the history data stored in the history
data storage unit 29. Specifically, the difference
calculation unit 26 searches the history data storage unit
29 using the position information as a key, and reads the
average value corresponding to the position information.
25 For each measured item, the difference calculation unit 26
calculates a difference value that is a difference between
the measured value included in the operation data extracted
by the data extraction unit 25 and the average value
included in the history data in the history data storage
30 unit 29 for each position information. The difference
calculation unit 26 distributes difference data to the data
receiving device 3 from which the distribution request is
acquired, the difference data including the position
13
information and information on the measured item included
in the operation data extracted by the data extraction unit
25, and information on the difference value calculated.
[0026] Next, the configuration of the data receiving
5 device 3 will be described. FIG. 4 is a block diagram
illustrating an example of the configuration of the data
receiving device 3 according to the first embodiment. The
data receiving device 3 includes a data acquisition unit 31.
The data acquisition unit 31 acquires the history data from
10 the data distribution device 2. The data acquisition unit
31 also makes the distribution request specifying a
necessary measured item to the data distribution device 2,
and acquires the difference data for the measured item
specified in the distribution request. The data
15 acquisition unit 31 uses the history data and difference
data acquired to restore the measured value of the measured
item specified in the distribution request. The data
acquisition unit 31 includes a connection execution unit 32,
a history data reception unit 35, and a history data
20 storage unit 36.
[0027] The history data reception unit 35 receives the
history data from the history data synchronization unit 30
of the data distribution device 2 after the start of the
train 100. The history data reception unit 35 causes the
25 history data storage unit 36 to store the history data
received.
[0028] The history data storage unit 36 stores the
history data received by the history data reception unit 35.
The content of the history data stored in the history data
30 storage unit 36 is identical to the content of the history
data that is stored in the history data storage unit 29 of
the data distribution device 2 and is used when the
difference calculation unit 26 of the data distribution
14
device 2 calculates the difference value.
[0029] The connection execution unit 32 makes the
distribution request specifying the necessary measured item
to the data distribution device 2, and acquires the
5 difference data based on the measured item specified in the
distribution request. The connection execution unit 32
includes a request transmission unit 33 and a difference
data decoding unit 34.
[0030] The request transmission unit 33 makes the
10 distribution request specifying the necessary measured item
to the data distribution device 2. The request
transmission unit 33 accepts an operation by a user
specifying the measured item from an input unit (not shown),
generates the distribution request specifying the measured
15 item accepted, and transmits the distribution request to
the data distribution device 2.
[0031] The difference data decoding unit 34 acquires,
from the data distribution device 2, the difference data
for the measured item specified in the distribution request
20 by the request transmission unit 33. On the basis of the
position information and information on the measured item
included in the difference data acquired, the difference
data decoding unit 34 reads the average value corresponding
to each position information for each measured item from
25 the history data in the history data storage unit 36. For
each measured item, the difference data decoding unit 34
adds together the difference value included in the
difference data acquired and the average value read for
each position information, and restores the measured value
30 of the measured item specified in the distribution request
by the request transmission unit 33.
[0032] In the present embodiment, the data distribution
device 2 does not distribute information on the measured
15
value as is to the data receiving device 3, but distributes
information on the difference value between the average
value of the measured values measured at the same train
position in past travel and the latest measured value. The
5 train 100 travels on a route predetermined by a line. The
route on which the train 100 travels typically includes a
curve, an uphill, a downhill, and the like. For example,
when the train 100 comes to a curve and applies the brakes,
the air pressure of the brakes changes from the air
10 pressure before coming to the curve. Thus, in time
sequence, the air pressure of the brakes varies in the
amount of change, that is, a difference between two pieces
of data that are continuous in time series.
[0033] On the other hand, when the train 100 comes to a
15 curve, the air pressure of the brakes at the train position
where the train 100 comes to the curve is estimated to take
a value similar to the air pressure of the brakes at the
same train position when the train 100 traveled the same
line in the past. In other words, the difference value
20 between the average value of the measured values measured
at the same train position and the latest measured value is
estimated to be smaller than the difference value between
the previous measured value and the latest measured value
that are measured in time series. Also, the difference
25 value between the average value of the measured values
measured at the same train position and the latest measured
value is estimated to fall within a certain range at each
train position and not take a prominent value at a certain
train position.
30 [0034] Therefore, the data distribution device 2
distributes, to the data receiving device 3, the
information on the difference value between the average
value of the measured values measured at the same train
16
position and the latest measured value. The data
distribution device 2 can reduce the bandwidth for
distributing the information on the difference value, that
is, reduce the amount of data, as compared to the case of
5 distributing the measured values as is and the case of
distributing the difference value between the two measured
values measured in time series. The data distribution
device 2 can reduce the amount of data and distribute the
information on the difference value without generating an
10 unnecessary bandwidth.
[0035] Next, data distribution processing in the data
distribution system 10 will be described. First, the
processing of synchronizing the history data between the
data distribution device 2 and the data receiving device 3
15 will be described. FIG. 5 is a flowchart illustrating the
processing in which the data distribution device 2 and the
data receiving device 3 synchronize the history data in the
data distribution system 10 according to the first
embodiment.
20 [0036] In the data distribution device 2, after the
start of the train 100, the history data synchronization
unit 30 refers to the history data storage unit 29, obtains
a difference between the history data at the time of the
start of the train 100 last time and the latest history
25 data acquired by the last operation, and generates
information on the difference obtained as additional
information (step S1). The history data synchronization
unit 30 performs connection processing with the history
data reception unit 35 of the data receiving device 3 to
30 establish a connection therewith, and transmits the
additional information to the history data reception unit
35 (step S2). Here, in the data distribution device 2, the
difference calculation unit 26 calculates the difference
17
value using the latest history data. That is, the
difference calculation unit 26 updates the history data
used for calculating the difference value from the history
data at the time of the start of the train 100 last time to
5 the latest history data. Note that when the train 100 is
started next time, the latest history data used this time
becomes the history data at the time of the start of the
train 100 last time.
[0037] In the data receiving device 3, after the start
10 of the train 100, the history data reception unit 35
performs the connection processing with the history data
synchronization unit 30 of the data distribution device 2
to establish the connection therewith, and receives the
additional information from the history data
15 synchronization unit 30. The history data reception unit
35 updates the history data stored in the history data
storage unit 36 using the additional information received
(step S3). As a result, the data distribution device 2 and
the data receiving device 3 can synchronize the history
20 data and hold the history data having the same content.
[0038] Note that in the data distribution device 2, the
history data synchronization unit 30 may read the history
data stored in the history data storage unit 29 and
transmit the history data to the data receiving device 3,
25 and in the data receiving device 3, the history data
reception unit 35 may overwrite, that is, update the
history data stored in the history data storage unit 36
with the history data received. In the case of
transmitting the history data as is, the history data
30 synchronization unit 30 transmits a large amount of data to
the history data reception unit 35 of the data receiving
device 3 compared to the case of transmitting the
additional information, but can reduce the processing load
18
for generating the addition information. The history data
synchronization unit 30 may transmit the additional
information or the history data as is to the data receiving
device 3 depending on the number of data receiving devices
5 3 to which the data is distributed.
[0039] Next, there will be described the processing in
which the data distribution device 2 acquires the operation
data from the vehicle information management device 1 after
the train 100 starts operating, and stores the history data.
10 FIG. 6 is a flowchart illustrating the processing in which
the data distribution device 2 stores the history data in
the data distribution system 10 according to the first
embodiment.
[0040] In the data distribution device 2, the data
15 acquisition unit 21 periodically acquires the operation
data from the vehicle information management device 1 (step
S11), and duplicates the operation data each time it is
acquired (step S12). The data acquisition unit 21 outputs
the duplicated operation data to the data extraction unit
20 25 and the history data calculation unit 28. The history
data calculation unit 28 calculates, for each measured item,
the average value of the measured values for each position
information every time the operation data is acquired from
the data acquisition unit 21 (step S13). As described
25 above, the history data calculation unit 28 calculates the
average value using the measured value of the latest
operation data and the measured value of the operation data
acquired in the past. Using the average value calculated,
the history data calculation unit 28 causes the history
30 data storage unit 29 to store information on the average
value corresponding to each position information for each
measured item as the history data (step S14). The data
distribution device 2 repeatedly performs the above
19
processing while periodically acquiring the operation data
from the vehicle information management device 1.
[0041] Note that the history data calculation unit 28
does not update the history data used when the difference
5 calculation unit 26 calculates the difference value, but
causes the history data storage unit 29 to store the
history data as another history data. At the end of the
operation of the train 100, two pieces of the history data
are stored in the history data storage unit 29. As
10 described above, after the start of the train 100, the
history data synchronization unit 30 generates the
additional information from the difference between the
history data at the time of the start of the train 100 last
time and the latest history data. The two pieces of the
15 history data stored in the history data storage unit 29 at
the end of the operation of the train 100 serve as the
history data at the time of the start of the train 100 last
time and the latest history data when the train 100 is
started next time.
20 [0042] Next, there will be described the processing in
which the data distribution device 2 acquires the operation
data from the vehicle information management device 1 after
the train 100 starts operating, calculates the difference
value, and distributes the difference data to the data
25 receiving device 3. FIG. 7 is a flowchart illustrating the
processing in which the data distribution device 2
distributes the difference data in the data distribution
system 10 according to the first embodiment.
[0043] In the data receiving device 3, the request
30 transmission unit 33 receives specification of a measured
item from a user, and generates a distribution request
specifying the measured item desired (step S21). The
request transmission unit 33 establishes a connection with
20
the request analysis unit 24 of the data distribution
device 2, and transmits the distribution request to the
request analysis unit 24 (step S22).
[0044] In the data distribution device 2, the request
5 analysis unit 24 establishes the connection upon receiving
a connection request from the request transmission unit 33
of the data receiving device 3, and acquires the
distribution request from the request transmission unit 33.
The request analysis unit 24 analyzes the distribution
10 request acquired and determines a measured item in the
operation data to be distributed to the data receiving
device 3 from which the distribution request is transmitted
(step S23). On the basis of the specification of the
measured item from the request analysis unit 24, the data
15 extraction unit 25 extracts the operation data for the
measured item specified from the operation data that is
acquired from the data acquisition unit 21 (step S24).
[0045] The difference calculation unit 26 acquires the
position information and information on the measured item
20 from the operation data extracted by the data extraction
unit 25. The difference calculation unit 26 uses the
position information as a key and inquires of the history
data storage unit 29 about the history data for each
measured item, that is, the measured item specified by the
25 data receiving device 3 (step S25). The difference
calculation unit 26 acquires, from the history data storage
unit 29, the average value corresponding to the position
information acquired for each measured item extracted by
the data extraction unit 25 (step S26). Note that the
30 difference calculation unit 26 may acquire the operation
data from the data acquisition unit 21, acquire the
information on the measured item specified by the
distribution target from the request analysis unit 24, and
21
perform the processings in steps S25 and S26 in parallel
with the processing by the data extraction unit 25 in step
S24.
[0046] The difference calculation unit 26 calculates the
5 difference value between the measured value of the
operation data extracted by the data extraction unit 25 and
the average value of the history data (step S27). The
difference calculation unit 26 distributes, to the data
receiving device 3 from which the distribution request is
10 transmitted, the difference data including the position
information and information on the measured item that are
included in the operation data extracted by the data
extraction unit 25 and the difference value calculated
(step S28). If no disconnection request has been made from
15 the data receiving device 3 (No in step S29), the data
distribution device 2 repeatedly performs the processings
from step S24 to step S28. If a disconnection request has
been made from the data receiving device 3 (Yes in step
S29), the data distribution device 2 breaks the connection
20 and ends the processing. When a plurality of the data
receiving devices 3 are connected to the data distribution
device 2, the data distribution device 2 and the data
receiving devices 3 perform the above processing for each
combination of the data distribution device 2 and the data
25 receiving device 3.
[0047] Next, a hardware configuration of the data
distribution device 2 will be described. In the data
distribution device 2, the history data storage unit 29 is
a memory. The other configurations in the data
30 distribution device 2 are implemented by a processing
circuit. That is, the data distribution device 2 includes
the processing circuit that can reduce the amount of data
of the measured value included in the operation data and
22
distribute the data to the data receiving device 3 by using
the position information of the train 100. The processing
circuit may be a memory and a processor executing programs
stored in the memory, or may be dedicated hardware.
5 [0048] FIG. 8 is a diagram illustrating an example of a
case where the processing circuit of the data distribution
device 2 according to the first embodiment includes a
processor and a memory. When the processing circuit
incudes a processor 91 and a memory 92, each function of
10 the processing circuit of the data distribution device 2 is
implemented by software, firmware, or a combination of
software and firmware. The software or firmware is
described as programs and stored in the memory 92. The
processing circuit implements the functions by the
15 processor 91 reading and executing the programs stored in
the memory 92. That is, the processing circuit includes
the memory 92 for storing the programs, the execution of
which results in reducing the amount of data of the
measured values included in the operation data and
20 distributing the data to the data receiving device 3 by
using the position information of the train 100. It can
also be said that these programs cause a computer to
execute procedures and methods related to the data
distribution device 2.
25 [0049] Here, the processor 91 may be a central
processing unit (CPU), a processing unit, an arithmetic
unit, a microprocessor, a microcomputer, or a digital
signal processor (DSP). The memory 92 corresponds to a
non-volatile or volatile semiconductor memory such as a
30 random access memory (RAM), a read only memory (ROM), a
flash memory, an erasable programmable ROM (EPROM), or an
electrically EPROM (EEPROM (registered trademark)), a
magnetic disk, a flexible disk, an optical disk, a compact
23
disc, a mini disc, a digital versatile disc (DVD), or the
like.
[0050] FIG. 9 is a diagram illustrating an example of a
case where the processing circuit of the data distribution
5 device 2 according to the first embodiment includes
dedicated hardware. When the processing circuit includes
dedicated hardware, a processing circuit 93 illustrated in
FIG. 9 corresponds to a single circuit, a complex circuit,
a programmed processor, a parallel-programmed processor, an
10 application specific integrated circuit (ASIC), a field
programmable gate array (FPGA), or a combination of those,
for example. The functions of the data distribution device
2 may be implemented individually or collectively by the
processing circuit 93.
15 [0051] Note that the functions of the data distribution
device 2 may be implemented partly by dedicated hardware
and partly by software or firmware. The processing circuit
can thus implement the aforementioned functions by
dedicated hardware, software, firmware, or a combination of
20 these.
[0052] A hardware configuration of the data receiving
device 3 is similar to the hardware configuration of the
data distribution device 2. In the data receiving device 3,
the history data storage unit 36 is a memory. The other
25 configurations in the data receiving device 3 are
implemented by a processing circuit.
[0053] As described above, according to the present
embodiment, the data distribution device 2 distributes, to
the data receiving device 3, the information on the
30 difference value between the average value of the measured
values measured at the same train position in past travel
and the latest measured value. The data distribution
device 2 can thus reduce the amount of data and distribute
24
the information on the difference value without generating
an unnecessary bandwidth and without being affected by the
route on which the train 100 travels.
[0054] Note that the history data stored in the history
5 data storage unit 29 of the train 100 can be used for
another train running on the same line. For example, when
another train is to be operated on a line different from
the previous one, the other train can easily acquire an
average value based on past measured values by using the
10 history data of the train 100.
[0055] Second Embodiment.
In a second embodiment, the data distribution device 2
and the data receiving device 3 include a plurality of
pieces of history data for each measured item. Differences
15 from the first embodiment will be described.
[0056] The configurations of the data distribution
system 10, the data distribution device 2, and the data
receiving device 3 are similar to those of the first
embodiment. In the train 100, the measured value of each
20 measured item is considered to be a measured value similar
to the measured value that is measured in the past at the
same train position. However, it is assumed that the
characteristics of the measured value vary depending on
conditions such as the operating mode of the train 100, the
25 operation hours of the train 100, and the weather at the
time of operation of the train 100.
[0057] For example, even at the same train position, the
speed of the train 100 is different in a case where the
train 100 is operated as a type of train that stops at each
30 station and in a case where the train is operated as a type
of train that does not stop at all stations such as an
express or rapid train, so that the measured value may
exhibit different characteristics depending on the measured
25
item.
[0058] Also, even when the train 100 is operated as the
same type of train, the speed of the train 100, the level
of congestion of passengers, and the like are different
5 even at the same train position in the morning and evening
commuting hours and in the daytime hours, so that the
measured value may exhibit different characteristics
depending on the measured item. Similarly, even at the
same train position, the speed of the train 100, the level
10 of congestion of passengers, and the like are different in
a case where the train 100 is operated on weekdays and in a
case where the train is operated on holidays, so that the
measured value may exhibit different characteristics
depending on the measured item.
15 [0059] In addition, different weather conditions on the
day on which the train 100 is operated such as rainy, sunny,
and cloudy weather cause differences in the effectiveness
of the brakes, the level of congestion of passengers, and
the like, so that the measured value may exhibit different
20 characteristics depending on the measured item. Similarly,
even at the same train position, the set temperature of an
air conditioner and the like are different in a case where
the temperature of the day on which the train 100 is
operated is high and in a case where the temperature is low,
25 so that the measured value may exhibit different
characteristics depending on the measured item.
[0060] Therefore, in the second embodiment, the vehicle
information management device 1 distributes, to the data
distribution device 2, the operation data while including
30 information such as train type information, time
information, and weather information. In the data
distribution device 2, the history data calculation unit 28
calculates the history data using the operation data under
26
the same condition, and causes the history data storage
unit 29 to store the history data. Specifically, when the
operation data includes the train type information such as
local and express trains, the history data calculation unit
5 28 calculates the history data for each train type. For
example, the history data calculation unit 28 calculates
history data for the local train and history data for the
express train, and causes the history data storage unit 29
to store the history data. When the operation data
10 includes the time information, the history data calculation
unit 28 calculates the history data for each time period.
For example, the history data calculation unit 28
calculates history data for the time period of 7:00 to 8:59
and history data for the time period of 9:00 to 10:59, and
15 causes the history data storage unit 29 to store the
history data. When the operation data includes the weather
information, the history data calculation unit 28
calculates the history data for each weather. For example,
the history data calculation unit 28 calculates history
20 data for the sunny weather and history data for the rainy
weather, and causes the history data storage unit 29 to
store the history data. Note that the history data
calculation unit 28 may calculate the history data using
the information on a plurality of conditions. For example,
25 the history data calculation unit 28 may calculate the
history data for the local train, for the time period of
7:00 to 8:59, and for the sunny weather, and causes the
history data storage unit 29 to store the history data.
The history data calculation unit 28 classifies the
30 operation data into a plurality of types using at least one
of the train type, time period, and weather information,
generates the history data for each type, and causes the
history data storage unit 29 to store the history data for
27
each type.
[0061] The history data storage unit 29 stores all the
history data calculated by the history data calculation
unit 28. The storage capacity of the history data storage
5 unit 29 of the second embodiment is larger than the storage
capacity of the history data storage unit 29 of the first
embodiment.
[0062] The history data synchronization unit 30
generates additional information for all the history data
10 stored in the history data storage unit 29, and transmits
the additional information to the history data reception
unit 35 of the data receiving device 3. Note that the
history data synchronization unit 30 may immediately
acquire the operation data from the train 100 after the
15 train 100 is started, select one piece of history data from
a plurality of pieces of the history data on the basis of
the conditions of the current train operation, generate the
additional information only for the history data selected,
and transmit the additional information to the history data
20 reception unit 35 of the data receiving device 3.
Alternatively, the history data synchronization unit 30 may
immediately acquire the operation data from the train 100
after the train 100 is started, select one piece of history
data from a plurality of pieces of the history data on the
25 basis of the conditions of the current train operation, and
transmit the selected history data as is to the history
data reception unit 35 of the data receiving device 3.
[0063] The difference calculation unit 26 selects one
piece of history data from the plurality of pieces of the
30 history data stored in the history data storage unit 29 on
the basis of the conditions of the current train operation,
and calculates a difference value using a representative
value of the selected history data. The difference
28
calculation unit 26 may acquire information on the history
data to be used from the history data synchronization unit
30.
[0064] In the data receiving device 3, the history data
5 reception unit 35 receives the history data corresponding
to the current operation of the train 100 from the data
distribution device 2, and then causes the history data
storage unit 36 to store the history data. The difference
data decoding unit 34 restores the measured value using the
10 history data distributed from the data distribution device
2 and stored in the history data storage unit 36. Note
that the processing in which the data receiving device 3
transmits the distribution request to the data distribution
device 2, and the data distribution device 2 generates the
15 difference data on the basis of the distribution request
and distributes the difference data to the data receiving
device 3 is similar to that of the first embodiment.
[0065] As described above, according to the present
embodiment, the data distribution device 2 stores the
20 plurality of pieces of the history data for each condition
on the basis of the conditions of the train 100 at the time
of operation, generates the difference data using the
history data that matches the conditions at the time of
operation, and distributes the difference data to the data
25 receiving device 3. The magnitude of the difference value
at each train position can be expected to be smaller than
that of the first embodiment. Therefore, the data
distribution device 2 can further reduce the amount of data
when distributing the difference data as compared to the
30 case of the first embodiment.
[0066] Third Embodiment.
In a third embodiment, the data distribution device 2
generates difference data for all measured items included
29
in the operation data acquired, and transmits the
difference data to the data receiving device 3.
Differences from the first embodiment will be described.
[0067] As described above, the data receiving device 3
5 can be connected to the data distribution device 2 via a
wireless network. In this case, the data receiving device
3 can be installed in a ground facility and used as a
device for collecting information on the operating state of
the train 100 on the ground side. For example, in the data
10 receiving device 3, the request transmission unit 33
specifies, in the distribution request to the data
distribution device 2, all the measured items included in
the operation data generated by the vehicle information
management device 1. The data distribution device 2
15 generates the difference data for all the measured items
and distributes the data to the data receiving device 3.
As a result, the data receiving device 3 can acquire all
the information included in the operation data generated by
the vehicle information management device 1 via the data
20 distribution device 2.
[0068] Moreover, when the data distribution device 2 has
not received the distribution request from the data
receiving device 3 within a specified time after
establishing a connection with the data receiving device 3,
25 the data distribution device 2 may determine that the
distribution request for all the measured items has been
made from the data receiving device 3. The data
distribution device 2 generates the difference data for all
the measured items and distributes the data to the data
30 receiving device 3. As a result, the data receiving device
3 can acquire all the information included in the operation
data generated by the vehicle information management device
1 via the data distribution device 2 without transmitting
30
the distribution request. Here, all the measured items
need only include necessary measured items that are
specified in advance between the data receiving device 3
and the data distribution device 2 when the distribution
5 request is not transmitted.
[0069] When only the data receiving device 3 on the
ground side is connected to the data distribution device 2,
the data distribution device 2 may generate the difference
data for all the measured items after establishing a
10 connection with the data receiving device 3 and distribute
the data to the data receiving device 3. As a result, the
data receiving device 3 can acquire all the information
included in the operation data generated by the vehicle
information management device 1 via the data distribution
15 device 2 without transmitting the distribution request.
Here, all the measured items need only include necessary
measured items that are specified in advance between the
data receiving device 3 and the data distribution device 2
when the distribution request is not transmitted.
20 [0070] As described above, according to the present
embodiment, the data distribution device 2 generates the
difference data for all the measured items and distributes
the data to the data receiving device 3 when the
distribution request specifying all the measured items is
25 acquired from the data receiving device 3, or when the
specified condition is met. As a result, the data
receiving device 3 can acquire all the information included
in the operation data generated by the vehicle information
management device 1.
30 [0071] The configurations illustrated in the
aforementioned embodiment merely illustrate examples of the
content of the present invention, and can thus be combined
with another known technique or partially omitted and/or
31
modified without departing from the scope of the present
invention.
Reference Signs List
5 [0072] 1 vehicle information management device; 2 data
distribution device; 3, 3-1 to 3-4 data receiving device;
10 data distribution system; 21, 31 data acquisition
unit; 22 data distribution unit; 23 connection management
unit; 24 request analysis unit; 25 data extraction unit;
10 26 difference calculation unit; 27 history data
management unit; 28 history data calculation unit; 29, 36
history data storage unit; 30 history data synchronization
unit; 32 connection execution unit; 33 request
transmission unit; 34 difference data decoding unit; 35
15 history data reception unit; 100 train.
32
We Claim:
1. A distribution device comprising:
a data acquisition unit to acquire operation data from
5 a vehicle information management device that collects a
measured value indicating an operating state of equipment
mounted on a train, the operation data including position
information indicating a position of the train when the
measured value is acquired and information on the measured
10 value;
a history data management unit to determine a
representative value for each position information,
generate history data including the position information
and information on the representative value, store the
15 history data, and distribute the history data to a
receiving device; and
a connection management unit to read, on a basis of
the position information included in the operation data,
the representative value corresponding to the position
20 information from the history data, calculate a difference
value that is a difference between the measured value
included in the operation data and the representative value,
and distribute difference data including the position
information and information on the difference value to the
25 receiving device.
2. The distribution device according to claim 1, wherein
the operation data further includes information on a
measured item,
30 the history data management unit determines the
representative value for each measured item and generates
the history data including the position information, the
measured item, and the representative value, and
33
when the connection management unit acquires a
distribution request specifying a measured item from the
receiving device, the connection management unit calculates
a difference value for the measured item specified, and
5 distributes difference data of the measured item specified
to the receiving device from which the distribution request
is acquired.
3. The distribution device according to claim 2, wherein
10 when a plurality of the receiving devices are present
and each make a distribution request specifying a different
measured item, the connection management unit calculates a
difference value for the measured item specified for each
of the receiving devices and distributes difference data of
15 the measured item specified to a corresponding one of the
receiving devices from which the distribution request is
made.
4. The distribution device according to any one of claims
20 1 to 3, wherein
the history data management unit classifies the
operation data into a plurality of types using at least one
condition among a train type, a time period, and weather,
generates and stores the history data for each of the types,
25 selects one history data from a plurality of the history
data on a basis of a condition of a current train operation,
and distributes the history data selected to the receiving
device, and
the connection management unit calculates the
30 difference value using the representative value of the
history data selected.
5. The distribution device according to any one of claims
34
1 to 4, wherein
the representative value is an average value of the
measured values included in the operation data acquired at
different times.
5
6. A receiving device comprising:
a history data storage unit to store history data
acquired from the distribution device according to claim 1;
and
10 a connection execution unit to acquire difference data
from the distribution device and restore, for each position
information, a measured value indicating an operating state
of equipment mounted on a train by using a difference value
included in the difference data and a representative value
15 included in the history data.
7. The receiving device according to claim 6, wherein
the connection execution unit makes a distribution
request specifying a measured item to the distribution
20 device, acquires difference data for the measured item
specified, and restores the measured value of the measured
item specified.
8. A data distribution system comprising:
25 the distribution device according to claim 1; and
the receiving device according to claim 6.
9. The data distribution system according to claim 8,
wherein
30 the receiving device makes a distribution request
specifying a measured item to the distribution device,
acquires difference data for the measured item specified,
and restores a measured value of the measured item
35
specified, and
the distribution device calculates a difference value
for the measured item specified in the distribution request,
and distributes the difference data of the measured item
5 specified to the receiving device from which the
distribution request is made.
10. The data distribution system according to claim 9,
wherein
10 when the distribution device acquires a distribution
request specifying a different measured item from each of a
plurality of the receiving devices present, the
distribution device calculates a difference value for the
measured item specified for each of the receiving devices
15 and distributes difference data of the measured item
specified to a corresponding one of the receiving devices
from which the distribution request is acquired.
11. The data distribution system according to any one of
20 claims 8 to 10, wherein
the distribution device classifies the operation data
into a plurality of types using at least one piece of
information among a train type, a time period, and weather,
generates and stores the history data for each of the types,
25 selects one history data from a plurality of the history
data on a basis of a condition of a current train operation,
distributes the history data selected to the receiving
device, and calculates the difference value using the
representative value of the history data selected, and
30 the receiving device restores the measured value
indicating the operating state of the equipment mounted on
the train by using the history data distributed.
36
12. The data distribution system according to any one of
claims 8 to 11, wherein
the representative value is an average value of the
measured values included in the operation data acquired at
5 different times.
13. A data distribution method comprising:
a data acquisition step of a distribution device
acquiring operation data from a vehicle information
10 management device that collects a measured value indicating
an operating state of equipment mounted on a train, the
operation data including position information indicating a
position of the train when the measured value is acquired
and information on the measured value;
15 a history data distribution step of the distribution
device determining a representative value for each position
information using the operation data, generating history
data including the position information and information on
the representative value, storing the history data, and
20 distributing the history data to a receiving device;
a difference data distribution step of the
distribution device reading, on a basis of the position
information included in the operation data, the
representative value corresponding to the position
25 information from the history data, calculating a difference
value that is a difference between the measured value
included in the operation data and the representative value,
and distributing difference data including the position
information and information on the difference value to the
30 receiving device; and
a restoring step of the receiving device acquiring the
history data and the difference data from the distribution
device and restoring, for each position information, the
37
measured value using the difference value included in the
difference data and the representative value included in
the history data.
5 14. The data distribution method according to claim 13,
further comprising
a requesting step of the receiving device making a
distribution request specifying a measured item to the
distribution device, wherein
10 in the history data distribution step, the
distribution device determines the representative value for
each measured item and generates the history data including
the position information, the measured item, and the
representative value,
15 in the difference data distribution step, the
distribution device calculates a difference value for the
measured item specified in the distribution request, and
distributes difference data of the measured item specified
to the receiving device from which the distribution request
20 is made, and
in the restoring step, the receiving device acquires
the difference data for the measured item specified, and
restores the measured value of the measured item specified.
25 15. The data distribution method according to claim 14,
wherein
in the difference data distribution step, when the
distribution device acquires the distribution request
specifying a different measured item from each of a
30 plurality of the receiving devices present, the
distribution device calculates a difference value for the
measured item specified for each of the receiving devices
and distributes difference data of the measured item
38
specified to a corresponding one of the receiving devices
from which the distribution request is acquired.
16. The data distribution method according to any one of
5 claims 13 to 15, wherein
in the history data distribution step, the
distribution device classifies the operation data into a
plurality of types using at least one piece of information
among a train type, a time period, and weather, generates
10 and stores the history data for each of the types, selects
one history data from a plurality of the history data on a
basis of a condition of a current train operation, and
distributes the history data selected to the receiving
device,
15 in the difference data distribution step, the
distribution device calculates the difference value using
the representative value of the history data selected, and
in the restoring step, the receiving device restores
the measured value using the history data distributed.
20
17. The data distribution method according to any one of
claims 13 to 16, wherein
the representative value is an average value of the
measured values included in the operation data acquired at
25 different times.