FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
FORWARD MONITORING DEVICE AND FORWARD MONITORING 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
FORWARD MONITORING DEVICE AND FORWARD MONITORING METHOD
5
Field
[0001] The present disclosure relates to a forward
monitoring device and a forward monitoring method each for
monitoring an area in the travelling direction of a train.
10
Background
[0002] Trains conventionally monitor an area on the
track in the travelling direction to detect an obstacle.
Patent Literature 1 discloses technology for allowing a
15 vehicle radar system to emit a radio wave from the train,
and measure a reflected wave, thereby detecting an obstacle
present on and by the track.
Citation List
20 Patent Literature
[0003] Patent Literature 1: Japanese Patent Application
Laid-open No. 2001-116840
Summary
25 Technical Problem
[0004] For the foregoing conventional technology,
unfortunately, the reflected wave may undergo a change
under the influence of a structure etc. alongside the track
even when the condition on the track in the travelling
30 direction does not change. When a change occurs in the
reflected wave, it is impossible to determine whether a
cause of that change is an obstacle on the track or a
structure located alongside the track. This presents a
3
problem of obstacle recognition rate being not high, that
is, a problem of possibility of misidentification of an
obstacle.
[0005] The present disclosure has been made in view of
5 the foregoing, and it is an object of the present
disclosure to provide a forward monitoring device capable
of reducing or preventing misidentification of an obstacle
in monitoring an area in the travelling direction of a
train.
10
Solution to Problem
[0006] To solve the above problem and achieve the
object, the present disclosure provides a forward
monitoring device to be installed on a train, the forward
15 monitoring device comprising: a map information storage
unit to store track information representing a location and
a track geometry of a track on which the train is to run; a
train information acquisition unit to obtain train location
information on the train; and an interceptor presence20 absence determination unit to determine, on a basis of the
track information, the train location information, and
interceptor candidate information, whether there is an
interceptor between the train and a first monitoring scope,
when the forward monitoring device monitors an obstacle on
25 the track in the first monitoring scope, the interceptor
being not the obstacle, the interceptor blocking a view of
the first monitoring scope from the train, the interceptor
candidate information indicating candidates for the
interceptor that blocks a view from the train, the first
30 monitoring scope including a spot on the track at a first
distance from the train along the track in a travelling
direction of the train.
4
Advantageous Effects of Invention
[0007] According to the present disclosure, the forward
monitoring device can provide an advantage of reducing or
preventing misidentification of the obstacle when
5 monitoring an area in the travelling direction of the
train.
Brief Description of Drawings
[0008] FIG. 1 is a diagram illustrating an example
10 configuration of a forward monitoring device according to a
first embodiment.
FIG. 2 is a first diagram illustrating an example of
operation of the forward monitoring device according to the
first embodiment.
15 FIG. 3 is a second diagram illustrating an example of
operation of the forward monitoring device according to the
first embodiment.
FIG. 4 is a third diagram illustrating an example of
operation of the forward monitoring device according to the
20 first embodiment.
FIG. 5 is a flowchart illustrating an operation of the
forward monitoring device according to the first
embodiment.
FIG. 6 is a diagram illustrating an example in which a
25 combination of a processor and a memory forms a processing
circuitry included in the forward monitoring device
according to the first embodiment.
FIG. 7 is a diagram illustrating an example in which a
dedicated hardware element forms the processing circuitry
30 included in the forward monitoring device according to the
first embodiment.
FIG. 8 is a diagram illustrating an example
configuration of a forward monitoring device according to a
5
second embodiment.
FIG. 9 is a first diagram illustrating an example of
operation of the forward monitoring device according to the
second embodiment.
5 FIG. 10 is a second diagram illustrating an example of
operation of the forward monitoring device according to the
second embodiment.
FIG. 11 is a third diagram illustrating an example of
operation of the forward monitoring device according to the
10 second embodiment.
FIG. 12 is a flowchart illustrating an operation of
the forward monitoring device according to the second
embodiment.
15 Description of Embodiments
[0009] A forward monitoring device and a forward
monitoring method according to embodiments of the present
disclosure will be described in detail below with reference
to the drawings.
20 [0010] First Embodiment.
FIG. 1 is a diagram illustrating an example
configuration of a forward monitoring device 12 according
to a first embodiment. The forward monitoring device 12 is
installed on a train 10. The train 10 monitors whether
25 there is an obstacle on a track 20 in the travelling
direction, using the forward monitoring device 12 during
running on the track 20. The train 10 includes a train
control device 11, the forward monitoring device 12, and an
output device 19. The forward monitoring device 12 is
30 connected to the train control device 11 and to the output
device 19. The forward monitoring device 12 includes a map
information storage unit 13, a train information
acquisition unit 14, an interceptor presence-absence
6
determination unit 15, a monitoring scope determination
unit 16, a monitoring unit 17, and an obstacle decision
unit 18.
[0011] The train control device 11 detects the location
5 and the speed of the train 10, using devices such as a
wayside device (not illustrated) installed on the ground
and an on-vehicle device and a tachogenerator (both not
illustrated) installed on the train 10. The train control
device 11 outputs, to the forward monitoring device 12,
10 train location information representing the detected
location of the train 10 and train speed information
indicating the detected speed of the train 10. The train
control device 11 detects the location of the train 10,
using a common method similarly to conventional cases.
15 [0012] The map information storage unit 13 stores track
information indicating the location and the track geometry
of the track 20 on which the train 10 is to run. The map
information storage unit 13 also stores location
information on track-side features including structures
20 such as a signal and a building alongside the track 20, and
natural objects such as a tree and a cliff alongside the
track 20. The map information storage unit 13 stores the
track information and the location information on trackside features collectively, the track information and the
25 location information defining map information. The track
information may be represented using a kilometrage from a
location defined as the start point, the latitude and the
longitude, coordinates providing three-dimensionally
measured points, etc., or a combination thereof. The
30 location of a track-side feature may be represented by the
latitude and the longitude, coordinates based on threedimensionally measured points, a combination of location
information on the immediately previous station and the
7
kilometrage, etc., or a combination thereof. When, for
example, the track information and the location information
on track-side features are represented using threedimensional coordinate values, the map information can be
5 generated by a mobile mapping system (MMS), etc. A trackside feature that is three-dimensionally measured using the
MMS can be represented by coordinates of points that form
that track-side feature, but coordinates of a single point
among the points that form that track-side feature may be
10 used as a representative value. Alternatively, a threedimensional shape model, which represented by an
approximate contour of each track-side feature, is
generated from points that define that feature, and the
thus generated model is defined as the location information
15 on a track-side feature. A single point Pi of a threedimensionally measured track-side feature can be expressed
as a three-dimensional coordinate value Pi(xi, yi, zi),
using coordinate values along three axes in an x-axis
direction, a y-axis direction, and a z-axis direction.
20 [0013] The map information storage unit 13 stores, as
the representative value of each track-side feature, for
example, data on coordinate values along three axes in the
x-axis direction, the y-axis direction, and the z-axis
direction, or stores that data representing a three25 dimensional shape model or points themselves. The map
information storage unit 13 also stores data on a
coordinate values along three axes in the x-axis direction,
the y-axis direction, and the z-axis direction, of each of
locations at predetermined intervals on the track 20
30 indicated in terms of the kilometrage, for example. Note
that the x-axis direction, the y-axis direction, and the zaxis direction can be defined such that, for example, the
x-y axes form the horizontal plane using the planar
8
cartesian coordinate system provided by the announcement of
Ministry of Land, Infrastructure and Transport used in
Japan, and the z-axis extends in the height direction.
Another usable coordinate system has the origin at any
5 point, e.g., the origin at the start point in kilometrage,
and the x-axis direction extending in the east direction,
the y-axis direction extending in the north direction, and
the z-axis direction extending in the vertically upward
direction. The unit of data representing the coordinate
10 values of each point can be, but not limited to, meters (m)
or the like. The map information storage unit 13 can store
a location coordinate of the track 20 represented by a
three-dimensional coordinate value by storing threedimensional coordinate values at individual locations in
15 kilometrage, e.g., at every one meter, on the track 20. In
the present embodiment, the map information storage unit 13
stores the track information and the location information
on track-side features, using a combination of a value in
kilometrage and a three-dimensional coordinate value. The
20 map information storage unit 13 may store the map
information during running of the train 10, that which was
measured in advance, or a combination thereof. Note that
the track information may be design information used for
laying the track 20.
25 [0014] The train information acquisition unit 14
obtains, from the train control device 11, the train
location information representing the location of the train
10 and the train speed information representing the speed
of the train 10. The train information acquisition unit 14
30 outputs the train location information and the train speed
information of the train 10 to the interceptor presenceabsence determination unit 15. Note that the train
information acquisition unit 14 may be configured to obtain
9
only the train location information, and output the train
location information to the interceptor presence-absence
determination unit 15.
[0015] The interceptor presence-absence determination
5 unit 15 obtains the track information from the map
information storage unit 13, and receives the train
location information and the train speed information from
the train information acquisition unit 14. In the present
embodiment, the interceptor presence-absence determination
10 unit 15 also obtains the location information on track-side
features from the map information storage unit 13, the
location information being defined as interceptor candidate
information that provides candidates for an interceptor
that blocks the view from the train 10. In monitoring an
15 obstacle on the track 20 in a first monitoring scope
including a spot on the track 20 at a first distance L1
from the train 10 along the track in the travelling
direction of the train 10, the interceptor presence-absence
determination unit 15 determines whether there in an
20 interceptor between the train 10 and the first monitoring
scope on the basis of the track information, the train
location information, the train speed information, and the
interceptor candidate information. The interceptor, which
is an object that blocks the view of the first monitoring
25 scope from the train 10, is neither present on the track 20
nor is an obstacle. In the present embodiment, the
interceptor presence-absence determination unit 15
determines whether a track-side feature will act as an
interceptor. When the interceptor presence-absence
30 determination unit 15 determines that there is an
interceptor, the interceptor presence-absence determination
unit 15 outputs interceptor information indicating that
there is an interceptor. For example, the interceptor
10
presence-absence determination unit 15 outputs, to the
monitoring scope determination unit 16, the interceptor
information that is interceptor location information
representing the location of the interceptor. Note that
5 the interceptor presence-absence determination unit 15 may
determine whether there is an interceptor between the train
10 and the first monitoring scope, on the basis of the
track information, the train location information, and the
interceptor candidate information, without using the train
10 speed information.
[0016] The monitoring scope determination unit 16
receives, from the interceptor presence-absence
determination unit 15, the interceptor information, i.e.,
the interceptor location information. The monitoring scope
15 determination unit 16 also receives the track information,
the train location information, and the train speed
information from the interceptor presence-absence
determination unit 15. Note that the monitoring scope
determination unit 16 may obtain the track information
20 directly from the map information storage unit 13, and may
obtain the train location information and the train speed
information directly from the train information acquisition
unit 14. On the basis of the interceptor location
information, the track information, the train location
25 information, and the train speed information, the
monitoring scope determination unit 16 calculates a second
distance L2 over which the view from the train 10 is not
blocked by the interceptor. The second distance L2 is a
distance from the train 10 shorter than the first distance
30 L1, on the track 20 along the track in the travelling
direction of the train 10. The monitoring scope
determination unit 16 determines that a second monitoring
scope, which includes a spot at the second distance L2, is
11
the monitoring scope for an obstacle. In addition, when
the monitoring scope determination unit 16 no longer
receives the interceptor location information from the
interceptor presence-absence determination unit 15, the
5 monitoring scope determination unit 16 returns the
monitoring scope for an obstacle, from the second
monitoring scope to the first monitoring scope. The
monitoring scope determination unit 16 outputs, to the
monitoring unit 17, information on the determined
10 monitoring scope.
[0017] The monitoring unit 17 monitors the monitoring
scope received from the monitoring scope determination unit
16 to detect an object. The object includes, as described
above, track-side features, which are structures such as a
15 signal and a building alongside the track 20 and natural
objects such as a tree and a cliff alongside the track 20.
In addition, the object includes an obstacle that hinders
running of the train 10 on the track 20. An obstacle is,
for example, an automobile or a person who has entered the
20 track 20 with a grade crossing closed, a rock fallen off a
cliff, a passenger fallen from a station platform, or a
passenger on a wheelchair left on a grade crossing. The
monitoring unit 17 is a device capable of detecting the
track-side feature and the obstacle, and is, for example, a
25 stereo camera including two or more cameras, a light
detection and ranging (LIDAR), a radio detection and
ranging (RADAR), or the like. The monitoring unit 17 may
be configured to include two or more devices.
[0018] The monitoring unit 17 generates a distance image
30 from data obtained by monitoring the monitoring scope, and
outputs the generated distance image to the obstacle
decision unit 18. The distance image is a monitoring
result which the monitoring unit 17 provides as a result of
12
monitoring area around the train 10. The distance image
includes one or both of a two-dimensional image, and a
three-dimensional image including distance information.
The monitoring unit 17 is installed on the leading vehicle
5 of the train 10. When the train 10 includes multiple
vehicles, the monitoring unit 17 is installed in each of
the leading and trailing vehicles as the leading vehicle
becomes the trailing vehicle or vice versa, depending on
the travelling direction. For example, when the train 10
10 is a ten-car train made up of vehicles no. 1 to no. 10,
vehicle no. 1 or vehicle no. 10 will be the leading
vehicle, depending on the travelling direction. In this
case, the monitoring unit 17 is provided on each of vehicle
no. 1 and vehicle no. 10 of the train 10. The forward
15 monitoring device 12 uses the monitoring unit 17 provided
on the leading vehicle in the travelling direction of the
train 10.
[0019] The obstacle decision unit 18 determines presence
or absence of an obstacle in the travelling direction of
20 the train 10 on the basis of the distance image received
from the monitoring unit 17. When the obstacle decision
unit 18 determines that the distance image includes an
obstacle, the obstacle decision unit 18 generates obstacle
detection information, which is information indicating that
25 an obstacle has been detected, and outputs the generated
obstacle detection information to the output device 19.
The obstacle detection information may be information
merely indicating that an obstacle has been detected, or
may include information on the location where the obstacle
30 has been detected.
[0020] Upon receiving the obstacle detection information
from the obstacle decision unit 18, the output device 19
outputs, to, for example, the driver of the train 10,
13
information indicating that an obstacle has been detected.
The output device 19 may provide a monitor, etc. that
indicates, for example, to the driver of the train 10, that
an obstacle has been detected. Alternatively, the output
5 device 19 may provide may provide a speaker, etc. that
emits, to that train driver, etc. voice that indicates that
an obstacle has been detected.
[0021] An operation of the forward monitoring device 12
will next be described. FIG. 2 is a first diagram
10 illustrating an example of operation of the forward
monitoring device 12 according to the first embodiment. In
FIG. 2, the train 10 runs in a direction from left to right
of FIG. 2 as indicated by the arrow above the train 10.
This also applies to the next and subsequent figures. FIG.
15 2 illustrates a situation in which the train 10 running on
the track 20 is trying to detect an obstacle 31 on the
track 20 in the travelling direction of the train 10. In
an attempt to detect the obstacle 31 on the track 20, the
train 10 does not monitor the entire area on the track 20
20 extending the first distance L1, which is a predetermined
distance, from the train 10, but monitors the monitoring
scope 30 that is the first monitoring scope including the
location at the first distance L1 from the train 10. This
is because the forward monitoring device 12 uses a stereo
25 camera, a LIDAR, a RADAR, or the like as the monitoring
unit 17, which may result in an unclear image except in the
monitoring scope 30 in focus in the train 10. The train 10
had monitored the area over the first distance L1 between
the train 10 and the monitoring scope 30 before the train
30 10 reached the location illustrated in FIG. 2. That is,
the train 10 monitored that area over the distance L1
between the train 10 and the monitoring scope 30 when the
train 10 was running on a section (not illustrated in FIG.
14
2) located on the left of the train 10. Note that the
location at the first distance L1 on the track 20 from the
train 10 may be the center of the first monitoring scope,
or may be a location nearer to the train 10 in the first
5 monitoring scope.
[0022] The track geometry of the track 20 on which the
train 10 is to run may not always be linear, but may curve
to the right or left as illustrated in FIG. 2. In
addition, the track 20 may be on a rising or falling slope.
10 In the example of FIG. 2, the train 10 is unable to view
the monitoring scope 30 on the track 20 located the first
distance L1 ahead of the train 10 in the travelling
direction because a natural object 22 alongside the track
20 blocks the train 10 viewing the monitoring scope 30. In
15 this case, the monitoring unit 17 of the forward monitoring
device 12 fails to detect the obstacle 31 in the monitoring
scope 30 as the natural object 22 blocks the monitoring
unit 17 viewing the obstacle 31. When the track 20 curves
to the left with respect to the travelling direction of the
20 train 10, opposite to the case of FIG. 2, the train 10 may
be unable to view the monitoring scope 30 on the track 20
located the first distance L1 ahead of the train 10 in the
travelling direction because a structure 21 alongside the
track 20 blocks the train 10 viewing the monitoring scope
25 30. In this case, the monitoring unit 17 of the forward
monitoring device 12 may fail to detect the obstacle 31 in
the monitoring scope 30 as the structure 21 blocks the
monitoring unit 17 viewing the obstacle 31.
[0023] In view of this, in the present embodiment, the
30 forward monitoring device 12 of the train 10 reduces the
distance to the monitoring scope 30 monitored by the train
10, to a distance to a location viewable from the train 10.
That is, the forward monitoring device 12 reduces the
15
distance to the monitoring scope 30 to a distance to a
location where the monitoring unit 17 can detect the
obstacle 31. FIG. 3 is a second diagram illustrating an
example of operation of the forward monitoring device 12
5 according to the first embodiment. FIG. 3 illustrates a
situation in which the distance to the monitoring scope 30
for monitoring the obstacle 31 on the track 20 in the
travelling direction of the train 10 is reduced by the
train 10 from the first distance L1 to the second distance
10 L2. In FIG. 3, the second distance L2, which is a distance
on the track 20 from the train 10, allows an area between
the train 10 and the monitoring scope 30 not to be blocked
by an interceptor such as the structure 21 or the natural
object 22. That is, the forward monitoring device 12
15 monitors the obstacle 31, with the monitoring scope 30 that
is the second monitoring scope including the location at
the second distance L2 less than the first distance L1.
Note that, in FIG. 3, an already-monitored scope 32 is the
area that had been monitored before the train 10 reached
20 the location illustrated in FIG. 3. By reducing the
distance to the monitoring scope 30 to the second distance
L2, the forward monitoring device 12 of the train 10 can
check whether the obstacle 31 is present on the track 20 in
the monitoring scope 30 located the second distance L2
25 ahead of the train 10. Note that the location at the
second distance L2 on the track 20 from the train 10 may be
the center of the second monitoring scope, or may be a
location in the second monitoring scope on a side of the
train 10.
30 [0024] The train 10 continues running, such that the
train 10 travels past the natural object 22, i.e., an
interceptor, and comes to view a location at the first
distance L1 on the track 20. At this point, the forward
16
monitoring device 12 of the train 10 returns the distance
to the monitoring scope 30 for monitoring the obstacle 31,
from the second distance L2 to the first distance L1. FIG.
4 is a third diagram illustrating an example of operation
5 of the forward monitoring device 12 according to the first
embodiment. FIG. 4 illustrates a situation in which as a
result of running in the travelling direction, i.e., in a
direction from left to right of the figure in the example
of FIG. 4, past the natural object 22, i.e., an
10 interceptor, the train 10 comes to view the location at the
first distance L1. In this process, the forward monitoring
device 12 gradually extends the distance to the monitoring
scope 30 from the second distance L2 such that the distance
is brought back to the first distance L1, thereby making it
15 possible to avoid occurrence of an unmonitored scope. As
discussed above, the forward monitoring device 12 of the
train 10 reduces the distance to the monitoring scope 30 to
the second distance L2 when the forward monitoring device
12 attempts to monitor presence or absence of the obstacle
20 31 on the track 20 in the monitoring scope 30 located the
first distance L1 ahead, but fails to view the spot at the
first distance L1 because a track-side feature such as the
structure 21 or the natural object 22 acts as an
interceptor.
25 [0025] An operation of the forward monitoring device 12
will next be described using a flowchart. FIG. 5 is a
flowchart illustrating an operation of the forward
monitoring device 12 according to the first embodiment. In
the forward monitoring device 12, the interceptor presence30 absence determination unit 15 obtains the track information
from the map information storage unit 13 (step S101). The
interceptor presence-absence determination unit 15 receives
the train location information and the train speed
17
information of the train 10 from the train information
acquisition unit 14 (step S102). The interceptor presenceabsence determination unit 15 obtains, from the map
information storage unit 13, the location information on
5 track-side features as the interceptor candidate
information (step S103). Note that the interceptor
presence-absence determination unit 15 may simultaneously
obtain the track information and the location information
on track-side features from the map information storage
10 unit 13. In addition, the interceptor presence-absence
determination unit 15 may obtain all the location
information on track-side features stored in the map
information storage unit 13, or may obtain only the train
location information on the train 10 and the location
15 information of track-side features in an area including the
first monitoring scope. The interceptor presence-absence
determination unit 15 determines whether there is an
interceptor that blocks the view, in an area from the train
10 to the first monitoring scope including the first
20 distance L1 in the travelling direction of the track 20
(step S104).
[0026] The interceptor presence-absence determination
unit 15 determines whether there is an interceptor at step
S104, in the following manner. Consider a line-of-sight
25 vector having a start point that is the train location
obtained from the train location information, and an end
point that is the spot at the first distance L1 in the
travelling direction of the track 20. When there exists
the structure 21 or the natural object 22 crossing this
30 line-of-sight vector, the interceptor presence-absence
determination unit 15 determines that there is an
interceptor that blocks the view, and otherwise, determines
that there is no interceptor. When the location
18
information on track-side features is in the form of a
three-dimensional shape model, the determination of whether
track-side features cross the line-of-sight vector is made
in accordance with based on whether a surface of that
5 three-dimensional shape model crosses the line-of-sight
vector. When the location information on track-side
features is in the form of points, the interceptor
presence-absence determination unit 15 determines that
there is an interceptor when, for example, points defining
10 the track-side feature exist in a vicinity of, e.g., within
5 cm from, the line-of-sight vector. When the location
information on track-side features is in the form of a
representative point, the interceptor presence-absence
determination unit 15 determines that there is an
15 interceptor when, for example, the representative point
defining the track-side feature exists in a vicinity of,
e.g., within 1 m from, the line-of-sight vector. The
height of the start point of the line-of-sight vector may
be defined as the level of the track or as the height of
20 the cab of the train 10. Similarly, the height of the end
point of the line-of-sight vector may be defined as the
level of the track or as a certain height above the track,
e.g., 1 m.
[0027] When there is no interceptor (step S104: No), the
25 interceptor presence-absence determination unit 15 does not
output interceptor information (step S105). Note that the
interceptor presence-absence determination unit 15 may
output, to the monitoring scope determination unit 16,
information indicating that there is no interceptor. The
30 interceptor presence-absence determination unit 15 also
outputs the track information, and the train location
information and the train speed information of the train
10, to the monitoring scope determination unit 16. On the
19
basis of the track information, and the train location
information and the train speed information on the train
10, the monitoring scope determination unit 16 determines
that the first monitoring scope including the first
5 distance L1 is the monitoring scope 30 as the monitoring
scope 30 for the monitoring unit 17 to monitor the obstacle
31 (step S106). When receiving no interceptor information
from the interceptor presence-absence determination unit
15, the monitoring scope determination unit 16 determines
10 that the first monitoring scope including the first
distance L1 is the monitoring scope 30 as an initial
setting. The monitoring scope determination unit 16
outputs, to the monitoring unit 17, information on the
first monitoring scope as the monitoring scope 30. The
15 monitoring unit 17 monitors the first monitoring scope as
the monitoring scope 30 (step S107). The obstacle decision
unit 18 determines the presence or absence of the obstacle
31 on the basis of the monitoring result of the monitoring
unit 17 (step S108).
20 [0028] When there is an interceptor (step S104: Yes),
the interceptor presence-absence determination unit 15
outputs interceptor information indicating that there is an
interceptor (step S109). The interceptor information is,
for example, a warning to the driver (not illustrated) of
25 the train 10. The warning to the driver is an alarm, a
display, or the like. Similarly to the output device 19,
the interceptor presence-absence determination unit 15 may
display the presence of an interceptor through a monitor or
the like, or may output voice indicating that there is an
30 interceptor through a speaker or the like. The interceptor
presence-absence determination unit 15 further outputs, to
the monitoring scope determination unit 16, interceptor
location information representing the location of the
20
interceptor as the interceptor information. The
interceptor presence-absence determination unit 15 also
outputs the track information, and the train location
information and the train speed information on the train
5 10, to the monitoring scope determination unit 16. On the
basis of the interceptor location information, the track
information, the train location information on the train
10, and the train speed information on the train 10, the
monitoring scope determination unit 16 calculates the
10 second distance L2 on the track 20 from the train 10, as
the distance to the monitoring scope 30 for the monitoring
unit 17 to monitor the obstacle 31 (step S110). A view over
the second distance L2 is not be blocked by an interceptor.
The monitoring scope determination unit 16 determines that
15 the second monitoring scope including the second distance
L2 is the monitoring scope 30 (step S111). The monitoring
scope determination unit 16 outputs, to the monitoring unit
17, information on the second monitoring scope as the
monitoring scope 30. The monitoring unit 17 monitors the
20 second monitoring scope as the monitoring scope 30 (step
S112). The obstacle decision unit 18 determines the
presence or absence of the obstacle 31 on the basis of the
monitoring result of the monitoring unit 17 (step S108).
[0029] When the obstacle decision unit 18 determines
25 that there is an obstacle (step S113: Yes), the obstacle
decision unit 18 generates obstacle detection information,
which is information indicating that an obstacle has been
detected, and outputs the generated obstacle detection
information to the output device 19 (step S114). When the
30 obstacle decision unit 18 determines that there is no
obstacle (step S113: No), the obstacle decision unit 18
skips the operation at step S114.
[0030] The forward monitoring device 12 periodically
21
repeats the foregoing operation. By reducing the distance
to the monitoring scope 30 to the second distance L2
shorter than the first distance L1, the forward monitoring
device 12 can continue monitoring the obstacle 31 even when
5 there is an interceptor between the train 10 and the
monitoring scope 30 located the first distance L1 ahead.
In addition, when there is no longer an interceptor between
the train 10 and the monitoring scope 30 located the first
distance L1 ahead, the forward monitoring device 12 can
10 return the monitoring condition to an initial condition of
monitoring the obstacle 31 by changing the distance to the
monitoring scope 30 to the first distance L1.
[0031] A hardware configuration of the forward
monitoring device 12 will next be described. In the
15 forward monitoring device 12, the map information storage
unit 13 is a memory. The monitoring unit 17 is, as
described above, a sensor such as a stereo camera or a
LIDAR. The train information acquisition unit 14, the
interceptor presence-absence determination unit 15, the
20 monitoring scope determination unit 16, and the obstacle
decision unit 18 are implemented in a processing circuitry.
The processing circuitry may be a processor that executes a
program stored in a memory, and the memory, or may be a
dedicated hardware element.
25 [0032] FIG. 6 is a diagram illustrating an example in
which a combination of a processor and a memory forms a
processing circuitry included in the forward monitoring
device 12 according to the first embodiment. When the
processing circuitry includes a processor 91 and a memory
30 92, each functionality of the processing circuitry of the
forward monitoring device 12 is implemented in software,
firmware, or a combination of software and firmware. The
software or firmware is described as a program, and is
22
stored in the memory 92. In the processing circuitry, each
functionality is implemented by the processor 91 by reading
and executing a program stored in the memory 92. That is,
the processing circuitry includes the memory 92 for storing
5 programs that cause the processing of the forward
monitoring device 12 to be performed. It can also be said
that these programs cause a computer to perform a procedure
and a method to be performed by the forward monitoring
device 12.
10 [0033] In this respect, the processor 91 may be a
central processing unit (CPU), a processing unit, a
computing unit, a microprocessor, a microcomputer, a
digital signal processor (DSP), or the like. In addition,
the memory 92 is, for example, a non-volatile or volatile
15 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 erasable
programmable ROM (EEPROM) (registered trademark); a
magnetic disk, a flexible disk, an optical disk, a compact
20 disc, a MiniDisc, a digital versatile disc (DVD), or the
like.
[0034] FIG. 7 is a diagram illustrating an example in
which a dedicated hardware element forms the processing
circuitry included in the forward monitoring device 12
25 according to the first embodiment. When the processing
circuitry includes a dedicated hardware element, a
processing circuitry 93 illustrated in FIG. 7 is, for
example, a single circuit, a set of multiple circuits, a
programmed processor, a parallel programmed processor, an
30 application specific integrated circuit (ASIC), a field
programmable gate array (FPGA), or a combination thereof.
The functionalities of the forward monitoring device 12 may
be implemented in the processing circuitry 93 on a
23
function-by-function basis, or may be implemented in the
processing circuitry collectively as a whole.
[0035] Each functionality of the forward monitoring
device 12 may be implemented partially in a dedicated
5 hardware element, and partially in software or firmware.
Thus, the processing circuitry can implement each
functionality described above in a dedicated hardware
element, software, firmware, or a combination thereof.
[0036] As described above, according to the present
10 embodiment, the interceptor presence-absence determination
unit 15 of the forward monitoring device 12 obtains, as
interceptor candidate information, location information on
track-side features such as the structure 21 and the
natural object 22, stored in the map information storage
15 unit 13, and determines whether there is an interceptor
that blocks the view from the train 10 to the monitoring
scope 30 that is the first monitoring scope. This can
prevent the forward monitoring device 12 from
misidentifying an interceptor present between the train 10
20 and the monitoring scope 30, as the obstacle 31. In
addition, when an interceptor blocks a view of the
monitoring scope 30 that is the first monitoring scope, the
forward monitoring device 12 reduces the distance from the
train 10 to the monitoring scope 30 to the second distance
25 L2 less than the first distance L1. By thus reducing the
distance to the monitoring scope 30, the forward monitoring
device 12 can continue monitoring the obstacle 31 and also
avoid unnecessary monitoring operation as the forward
monitoring device 12 does not monitor the scope which the
30 forward monitoring device 12 cannot directly monitor
because the view from the forward monitoring device 12 to
that scope is blocked.
[0037] Moreover, when the train 10 travels past the
24
natural object 22, i.e., an interceptor, and comes to view
a location at the first distance L1, the forward monitoring
device 12 gradually extends the distance to the monitoring
scope 30 such that the distance is brought from the second
5 distance L2 back to the first distance L1, thereby making
it possible to avoid occurrence of an unmonitored scope.
Note that the first distance L1 in the present embodiment
can be, but not limited to, for example, 300 m as a
distance for the train 10 to stop after applying a brake.
10 In addition, although the present embodiment has been
described assuming that the first distance L1 is a
constant, the forward monitoring device 12 may be
configured to change the first distance L1 according to the
train speed information or the running location of the
15 train 10.
[0038] Second Embodiment.
The first embodiment is based on the assumption that
track-side features such as the structure 21 and the
natural object 22 alongside the track 20 may act as an
20 interceptor. A second embodiment will next be described
giving an example in which another train running on a
parallel track acts as an interceptor.
[0039] FIG. 8 is a diagram illustrating an example
configuration of a forward monitoring device 12a according
25 to the second embodiment. The forward monitoring device
12a is installed on a train 10a. The train 10a monitors
whether there is the obstacle 31 on a track 20a in the
travelling direction, using the forward monitoring device
12a during running on the track 20a. In the present
30 embodiment, the train 10a is connected to a train traffic
control device 50 via wireless communication. The train
10a includes the forward monitoring device 12a in place of
the forward monitoring device 12 of the train 10 of the
25
first embodiment. The forward monitoring device 12a
includes an interceptor presence-absence determination unit
15a in place of the interceptor presence-absence
determination unit 15 of the forward monitoring device 12
5 of the first embodiment.
[0040] Similarly to the interceptor presence-absence
determination unit 15 of the first embodiment, the
interceptor presence-absence determination unit 15a obtains
the track information from the map information storage unit
10 13, and receives the train location information and the
train speed information of the train 10 from the train
information acquisition unit 14. In addition, the
interceptor presence-absence determination unit 15a of the
present embodiment obtains, from the train traffic control
15 device 50, location information on another train running on
a track extending along the track 20a as interceptor
candidate information that provides candidates for an
interceptor that blocks the view from the train 10a. In
monitoring the obstacle 31 on the track 20a in the first
20 monitoring scope including the first distance L1 from the
train 10a on the track 20a in the travelling direction of
the train 10a, the interceptor presence-absence
determination unit 15a determines, on the basis of the
track information, the train location information, the
25 train speed information, and the interceptor candidate
information, whether there is an interceptor between the
train 10a and the first monitoring scope, the interceptor
being not the obstacle 31, but blocking the view of the
first monitoring scope from the train 10a. In the present
30 embodiment, the interceptor presence-absence determination
unit 15a determines whether another train acts as an
interceptor. When the interceptor presence-absence
determination unit 15a determines that there is an
26
interceptor, the interceptor presence-absence determination
unit 15a outputs interceptor information indicating that
there is an interceptor. For example, the interceptor
presence-absence determination unit 15a outputs, to the
5 monitoring scope determination unit 16, interceptor
location information as the interceptor information.
[0041] The train traffic control device 50 manages
operation of the train 10a and other trains (not
illustrated), collecting the location information on these
10 individual trains train from the train 10a and the other
trains.
[0042] An operation of the forward monitoring device 12a
will next be described. FIG. 9 is a first diagram
illustrating an example of operation of the forward
15 monitoring device 12a according to the second embodiment.
In FIG. 9, the train 10a runs in a direction from left to
right of FIG. 9 as indicated by the arrow above the train
10a. In FIG. 9, also, in contrast to the train 10a running
on the track 20a in a direction from left to right of FIG.
20 9, another train 40 is running on a parallel track 20b in a
direction from right to left of FIG. 9, i.e., in the
opposite direction. This also applies to the next and
subsequent figures. In the situation illustrated in FIG.
9, the train 10a may misidentify the other train 40 in the
25 monitoring scope 30 as the obstacle 31 by monitoring the
monitoring scope 30. FIG. 10 is a second diagram
illustrating an example of operation of the forward
monitoring device 12a according to the second embodiment.
In the situation illustrated in FIG. 10, the other train 40
30 acts as an interceptor for the train 10a as the other train
40 blocks the view from the train 10a to the monitoring
scope 30.
[0043] In view of this, in the present embodiment, the
27
forward monitoring device 12a of the train 10a reduces the
distance to the monitoring scope 30 monitored by the train
10a, to a distance to a location viewable from the train
10a. That is, the forward monitoring device 12a reduces
5 the distance to the monitoring scope 30 to a distance to a
location where the monitoring unit 17 can detect the
obstacle 31. The forward monitoring device 12a obtains,
from the train traffic control device 50, the location
information on the other train 40 running on the parallel
10 track 20b. Then, when the other train 40 is included in
the monitoring scope 30, or the other train 40 acts as an
interceptor, the forward monitoring device 12a reduces the
distance to the monitoring scope 30, to a distance to a
location where the monitoring unit 17 can detect the
15 obstacle 31. FIG. 11 is a third diagram illustrating an
example of operation of the forward monitoring device 12a
according to the second embodiment. When the other train
40 is included in the monitoring scope 30 as illustrated in
FIG. 9, or the other train 40 between the train 10a and the
20 monitoring scope 30 acts as an interceptor as illustrated
in FIG. 10, the train 10a reduces the first distance L1 to
the monitoring scope 30 to the second distance L2, and
continues monitoring the obstacle 31. Note that although
not illustrated, after the other train 40 travels past the
25 train 10a, the train 10a returns the distance to the
monitoring scope 30, from the second distance L2 to the
first distance L1 similarly to the train 10 of the first
embodiment.
[0044] An operation of the forward monitoring device 12a
30 will next be described using a flowchart. FIG. 12 is a
flowchart illustrating an operation of the forward
monitoring device 12a according to the second embodiment.
In the forward monitoring device 12a, the interceptor
28
presence-absence determination unit 15a obtains the track
information from the map information storage unit 13 (step
S101). The interceptor presence-absence determination unit
15a receives the train location information and the train
5 speed information of the train 10 from the train
information acquisition unit 14 (step S102). The
interceptor presence-absence determination unit 15a
obtains, from the train traffic control device 50, the
location information on the other train 40 as the
10 interceptor candidate information (step S201). The
interceptor presence-absence determination unit 15a
determines whether there is an interceptor at step S104, in
the following manner. When the line-of-sight vector
crosses the location information on the other train 40, the
15 interceptor presence-absence determination unit 15a
determines that there is an interceptor, and otherwise,
determines that there is no interceptor. The interceptor
presence-absence determination unit 15a determines that the
line-of-sight vector crosses the location information on
20 the other train 40 and thus there is an interceptor when,
for example, the line-of-sight vector extends through the
vicinity of, e.g., a location at 1 m or less from, the
location information on the other train 40. When the
formation of the other train 40 is known, a solid
25 representing the contour of the other train 40 is placed at
the location information on the other train 40. In this
case, when that solid crosses the line-of-sight vector, the
interceptor presence-absence determination unit 15a
determines that there is an interceptor. Alternatively, a
30 scope of the parallel track within which the other train 40
exists is defined. In this case, when the line-of-sight
vector extends through that scope of the parallel track,
the interceptor presence-absence determination unit 15a
29
determines that there is an interceptor. The operation
thereafter is similar to the operation of the forward
monitoring device 12 in the first embodiment illustrated in
FIG. 5.
5 [0045] Note that FIGS. 9 to 11 are based on the
assumption that the other train 40 is a train approaching
the train 10a from the opposite direction, but the other
train 40 is not limited thereto. For example, a four-track
line includes a further parallel track disposed on the left
10 side in the travelling direction of the train 10a, and a
train on this further parallel track in the same travelling
direction as the train 10a, in which case the train 10a may
also obtain, from the train traffic control device 50,
interceptor candidate information that is location
15 information on that train running in the same travelling
direction.
[0046] As described above, according to the present
embodiment, the forward monitoring device 12a obtains the
interceptor candidate information, i.e., the information on
20 the other train 40 running on the parallel track 20b, and
determines whether there is an interceptor that blocks the
view from the train 10a to the monitoring scope 30 that is
the first monitoring scope. Also in this case, the forward
monitoring device 12a can provide an advantage similar to
25 the advantage of the forward monitoring device 12 of the
first embodiment.
[0047] Note that in the present embodiment, the forward
monitoring device 12a uses location information on the
other train 40 as the interceptor candidate information.
30 Alternatively, the forward monitoring device 12a may
further use the location information on track-side
features. Specifically, the forward monitoring device 12a
may perform the operation of step S201 illustrated in FIG.
30
12 before or after the operation of step S103 illustrated
in FIG. 5. This can further prevent the forward monitoring
device 12a from misidentifying an interceptor between the
train 10a and the monitoring scope 30 as the obstacle 31.
5 [0048] The configurations described in the foregoing
embodiments are merely examples. These configurations may
be combined with a known other technology, and
configurations of different embodiments may be combined
together. Moreover, part of the configurations may be
10 omitted and/or modified without departing from the spirit
thereof.
Reference Signs List
[0049] 10, 10a train; 11 train control device; 12, 12a
15 forward monitoring device; 13 map information storage
unit; 14 train information acquisition unit; 15, 15a
interceptor presence-absence determination unit; 16
monitoring scope determination unit; 17 monitoring unit;
18 obstacle decision unit; 19 output device; 20, 20a, 20b
20 track; 21 structure; 22 natural object; 30 monitoring
scope; 31 obstacle; 32 already-monitored scope; 40
another train; 50 train traffic control device.
31
We Claim :
1. A forward monitoring device to be installed on a
train, the forward monitoring device comprising:
a map information storage unit to store track
5 information representing a location and a track geometry of
a track on which the train is to run;
a train information acquisition unit to obtain train
location information on the train; and
an interceptor presence-absence determination unit to
10 determine, on a basis of the track information, the train
location information, and interceptor candidate
information, whether there is an interceptor between the
train and a first monitoring scope, when the forward
monitoring device monitors an obstacle on the track in the
15 first monitoring scope, the interceptor being not the
obstacle, the interceptor blocking a view of the first
monitoring scope from the train, the interceptor candidate
information indicating candidates for the interceptor that
blocks a view from the train, the first monitoring scope
20 including a spot on the track at a first distance from the
train along the track in a travelling direction of the
train.
2. The forward monitoring device according to claim 1,
25 wherein
the map information storage unit stores location
information on track-side features including a structure
and a natural object alongside the track, and
the interceptor presence-absence determination unit
30 obtains the location information on track-side features
from the map information storage unit, as the interceptor
candidate information, and determines whether the trackside features act as the interceptor.
32
3. The forward monitoring device according to claim 1 or
2, wherein
the interceptor presence-absence determination unit
5 obtains, from a train traffic control device, location
information on another train running on a parallel track,
as the interceptor candidate information, and determines
whether the other train acts as the interceptor, the train
traffic control device being a device that collects
10 location information on the train, and manages operation of
the train.
4. The forward monitoring device according to any one of
claims 1 to 3, wherein
15 when the interceptor presence-absence determination
unit determines that the interceptor is present, the
interceptor presence-absence determination unit outputs
interceptor information indicating that the interceptor is
present.
20
5. The forward monitoring device according to claim 4,
wherein
the interceptor presence-absence determination unit
outputs interceptor location information as the interceptor
25 information, and
the forward monitoring device further comprises
a monitoring scope determination unit to receive the
interceptor location information from the interceptor
presence-absence determination unit, and determine that a
30 second monitoring scope is a monitoring scope for the
obstacle, the second monitoring scope including a spot at a
second distance from the train on the track along the track
in the travelling direction of the train, over which second
33
distance a view from the train is not blocked by the
interceptor, the second distance being shorter than the
first distance.
5 6. The forward monitoring device according to claim 5,
wherein
when the monitoring scope determination unit no longer
receives the interceptor location information from the
interceptor presence-absence determination unit, the
10 monitoring scope determination unit returns the monitoring
scope for the obstacle to the first monitoring scope.
7. The forward monitoring device according to any one of
claims 1 to 6, wherein
15 the train information acquisition unit further obtains
train speed information on the train, and
the interceptor presence-absence determination unit
determines whether the interceptor is present further using
the train speed information.
20
8. A forward monitoring method for use in a forward
monitoring device to be installed on a train, the forward
monitoring method comprising:
a first step of, by a train information acquisition
25 unit, obtaining train location information on the train;
and
a second step of, by an interceptor presence-absence
determination unit, determining, on a basis of track
information representing a location and a track geometry of
30 a track on which the train is to run, the train location
information, and interceptor candidate information, whether
there is an interceptor between the train and a first
monitoring scope, when the forward monitoring device
34
monitors an obstacle on the track in the first monitoring
scope, the interceptor being not an obstacle, the
interceptor blocking a view of the first monitoring scope
from the train, the interceptor candidate information
5 indicating candidates for the interceptor that blocks a
view from the train, the first monitoring scope including a
spot on the track at a first distance from the train along
the track in a travelling direction of the train.
10 9. The forward monitoring method according to claim 8,
wherein
in the second step, the interceptor presence-absence
determination unit obtains location information on trackside features including a structure and a natural object
15 alongside the track, as the interceptor candidate
information, and determines whether the track-side features
act as the interceptor.
10. The forward monitoring method according to claim 8 or
20 9, wherein
in the second step, the interceptor presence-absence
determination unit obtains, from a train traffic control
device, location information on another train running on a
parallel track, as the interceptor candidate information,
25 and determines whether the other train acts as the
interceptor, the train traffic control device being a
device that collects location information on the train, and
manages operation of the train.
30 11. The forward monitoring method according to any one of
claims 8 to 10, wherein
in the second step, when the interceptor presenceabsence determination unit determines that the interceptor
35
is present, the interceptor presence-absence determination
unit outputs interceptor information indicating that the
interceptor is present.
5 12. The forward monitoring method according to claim 11,
wherein
in the second step, the interceptor presence-absence
determination unit outputs interceptor location information
as the interceptor information, and
10 the forward monitoring method further comprises
a third step of, by a monitoring scope determination
unit, receiving the interceptor location information from
the interceptor presence-absence determination unit, and
determining that a second monitoring scope is a monitoring
15 scope for the obstacle, the second monitoring scope
including a spot at a second distance from the train on the
track along the track in a travelling direction of the
train, over which second distance a view from the train is
not blocked by the interceptor, the second distance being
20 shorter than the first distance.
13. The forward monitoring method according to claim 12,
wherein
in the third step, when the monitoring scope
25 determination unit no longer receives the interceptor
location information from the interceptor presence-absence
determination unit, the monitoring scope determination unit
returns the monitoring scope for the obstacle to the first
monitoring scope.
30
14. The forward monitoring method according to any one of
claims 8 to 13, wherein
in the first step, the train information acquisition
36
unit further obtains train speed information on the train,
and
in the second step, the interceptor presence-absence
determination unit determines whether the interceptor is
5 present further using the train speed information.