FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
OBSTACLE DETECTION DEVICE AND OBSTACLE DETECTION 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
5
2
DESCRIPTION
Field
5 [0001] The present disclosure relates to an obstacle
detection device to be installed on a train and an obstacle
detection method.
Background
10 [0002] Conventionally, a train includes sensors such as
a camera and a radar, and monitors whether or not there is
an obstacle on a route. Such a technique is disclosed in
Patent Literature 1. It is difficult for a sensor such as
a camera or a radar to accurately monitor the entire range
15 on the route of the train due to a focal point set by each
device. Therefore, the train can perform effective
monitoring by determining a reference distance from the
train in consideration of a braking distance and the like
and performing monitoring by narrowing a region on the
20 basis of the reference distance.
Citation List
Patent Literature
[0003] Patent Literature 1: Japanese Patent Application
25 Laid-open No. 2019-188846
Summary
Technical Problem
[0004] However, according to the conventional technique
30 described above, in a case where an obstacle cannot be
detected due to a cause that disturbs a visual field of the
sensor, the train needs to change a distance in the
monitoring process to enable detection of the obstacle.
3
The cause that disturbs the visual field of the sensor is,
for example, a weather condition such as fog or storm, and
presence of a shielding object such as a building or a
natural object around a railway track. In this case, when
5 the monitoring distance is changed, there is a possibility
that an unmonitored region may be made on the route of the
train, and there has been a problem that the train may miss
an obstacle on the route.
[0005] The present disclosure has been made in view of
10 the above, and an object thereof is to obtain an obstacle
detection device capable of changing a monitoring distance
without missing an obstacle on a route of a train.
Solution to Problem
15 [0006] In order to solve the above problem and achieve
the object, an obstacle detection device according to the
present disclosure is installed on a train. The obstacle
detection device includes: a sensor to monitor a monitoring
region and output a monitoring result; an obstacle
20 detection unit to determine presence or absence of an
obstacle on a route of the train based on the monitoring
result, and output a detection result; a monitoring
distance determination unit to use the detection result to
determine a monitoring distance from the train to a
25 reference for monitoring by the sensor in front of the
train; and a monitoring region determination unit to use
the monitoring distance to determine the monitoring region
to be monitored by the sensor. When changing the
monitoring distance, the monitoring distance determination
30 unit acquires the monitoring region from the monitoring
region determination unit, and changes the monitoring
distance such that a part of a first monitoring region that
has been monitored overlaps with a part of a second
4
monitoring region based on the changed monitoring distance,
in order not to generate a region that is not monitored by
the sensor on a route of the train.
5 Advantageous Effects of Invention
[0007] According to the present disclosure, there is an
effect that the obstacle detection device can change a
monitoring distance without missing an obstacle on a route
of a train.
10
Brief Description of Drawings
[0008] FIG. 1 is a diagram illustrating a configuration
example of a train including an obstacle detection device
according to a first embodiment.
15 FIG. 2 is a diagram illustrating an example of a state
in which an obstacle is present between the train and a
monitoring region when the obstacle detection device
according to the first embodiment monitors the monitoring
region.
20 FIG. 3 is a diagram illustrating imagery of a change
in monitoring region when the obstacle detection device
according to the first embodiment changes a monitoring
distance.
FIG. 4 is a flowchart illustrating an action of the
25 obstacle detection device according to the first embodiment.
FIG. 5 is a diagram illustrating an example of a case
where processing circuitry included in the obstacle
detection device according to the first embodiment is
configured with a processor and a memory.
30 FIG. 6 is a diagram illustrating an example of a case
where processing circuitry included in the obstacle
detection device according to the first embodiment is
configured with dedicated hardware.
5
FIG. 7 is a diagram illustrating a configuration
example of a train including an obstacle detection device
according to a second embodiment.
FIG. 8 is a diagram illustrating a state in which a
5 monitoring distance determination unit of the obstacle
detection device according to the second embodiment
shortens a monitoring distance as a shielding object is
present.
FIG. 9 is a diagram illustrating imagery of a change
10 in monitoring distance when the monitoring distance
determination unit of the obstacle detection device
according to the second embodiment returns the monitoring
distance to an original state as the shielding object is no
longer present.
15 FIG. 10 is a flowchart illustrating an action of the
obstacle detection device according to the second
embodiment.
FIG. 11 is a diagram illustrating a configuration
example of a train including an obstacle detection device
20 according to a third embodiment.
FIG. 12 is a diagram illustrating a locational
relationship between the train and a monitoring region
based on a monitoring distance determined when there is no
obstacle by a monitoring distance determination unit of the
25 obstacle detection device according to the third embodiment.
FIG. 13 is a diagram illustrating a locational
relationship between the train and a monitoring region
based on a monitoring distance determined at a time of
obstacle tracking by the monitoring distance determination
30 unit of the obstacle detection device according to the
third embodiment.
FIG. 14 is a flowchart illustrating an action of the
obstacle detection device according to the third embodiment.
6
FIG. 15 is a diagram illustrating a configuration
example of a train including an obstacle detection device
according to a fourth embodiment.
FIG. 16 is a flowchart illustrating an action of the
5 obstacle detection device according to the fourth
embodiment.
Description of Embodiments
[0009] Hereinafter, an obstacle detection device and an
10 obstacle detection method according to embodiments of the
present disclosure will be described in detail with
reference to the drawings.
[0010] First Embodiment.
FIG. 1 is a diagram illustrating a configuration
15 example of a train 10 including an obstacle detection
device 30 according to a first embodiment. The train 10
includes a train control device 20 and the obstacle
detection device 30. During operation, the train 10
monitors whether or not there is an obstacle on a route by
20 using the obstacle detection device 30.
[0011] The train control device 20 controls traveling of
the train 10. Specifically, the train control device 20
detects a location and a speed of the train 10 by using a
ground coil (not illustrated) installed on the ground, an
25 on-board antenna (not illustrated) installed on the train
10, a tachometer generator, and the like. The train
control device 20 outputs train location information
indicating the detected location of the train 10 and train
speed information indicating the detected speed of the
30 train 10, to the obstacle detection device 30. A location
detection method of the train 10 in the train control
device 20 is a general method similar to a conventional
method. In addition, upon acquiring a detection result
7
indicating that an obstacle has been detected from an
obstacle detection unit 32 to be described later, the train
control device 20 performs control to stop or decelerate
the train 10.
5 [0012] The obstacle detection device 30 is installed on
the train 10 and monitors whether or not there is an
obstacle on the route of the train 10. A configuration of
the obstacle detection device 30 will be described. As
illustrated in FIG. 1, the obstacle detection device 30
10 includes a sensor 31, the obstacle detection unit 32, a
monitoring distance determination unit 33, and a monitoring
region determination unit 34.
[0013] The sensor 31 performs monitoring in a monitoring
region acquired from the monitoring region determination
15 unit 34 to be described later, and detects an object. The
object includes an obstacle that hinders traveling of the
train 10 on the route of the train 10. The obstacle is,
for example, an automobile or a person entering a railway
track while a railroad crossing is blocked, a fallen rock
20 from a cliff, a passenger who has fallen from a station
platform, a wheelchair left behind at a railroad crossing,
or the like. The sensor 31 is a measuring instrument
capable of detecting these obstacles, and is, for example,
a stereo camera including two or more cameras, light
25 detection and ranging (LIDAR), radio detection and ranging
(RADAR), or the like. The sensor 31 may include two or
more measuring instruments.
[0014] The sensor 31 outputs a monitoring result, which
is a result obtained by monitoring the monitoring region,
30 to the obstacle detection unit 32. The monitoring result
is a result of monitoring the monitoring region by the
sensor 31, and is, for example, a two-dimensional image, a
three-dimensional image, or the like. The sensor 31 is
8
installed on a head car of the train 10. In a case where
the train 10 is configured with a plurality of cars, the
head car is changed according to a traveling direction, and
thus the sensors 31 are installed on cars at both ends.
5 For example, in a case where the train 10 is a 10-car train
including the first to 10th cars, the first car or the 10th
car is to be the head car according to the traveling
direction. In this case, the sensors 31 are installed in
the first car and the 10th car of the train 10. The
10 obstacle detection device 30 uses the sensor 31 installed
in the head car in the traveling direction of the train 10.
[0015] The obstacle detection unit 32 determines
presence or absence of an obstacle on the route of the
train 10 on the basis of the monitoring result acquired
15 from the sensor 31. The obstacle detection unit 32 outputs
a detection result indicating, in the monitoring result,
the presence or absence of an obstacle, that is, whether or
not an obstacle has been detected, to the train control
device 20 and the monitoring distance determination unit 33.
20 The detection result may be only information indicating
whether or not an obstacle has been detected, or may
include information on a location of the obstacle when the
obstacle has been detected. Here, the sensor 31 monitors
the route of the train 10 from the train 10 to the
25 monitoring region. In a case where there is an obstacle
between the train 10 and the monitoring region, the
monitoring result may include, although not clear,
information indicating that an obstacle is present.
Therefore, the obstacle detection unit 32 may output
30 information indicating that there is a possibility of
presence of an obstacle in a region other than the
monitoring region, as a detection result to the train
control device 20 and the monitoring distance determination
9
unit 33.
[0016] The monitoring distance determination unit 33
uses the detection result acquired from the obstacle
detection unit 32, to determine a monitoring distance from
5 the train 10 to a reference for monitoring by the sensor 31
in front of the train 10. In a case where the acquired
detection result indicates that no obstacle has been
detected, the monitoring distance determination unit 33
determines, as the monitoring distance, a monitoring
10 distance defined based on performance of the sensor 31, a
speed of the train 10, and the like. In a case where the
acquired detection result indicates that an obstacle has
been detected, the monitoring distance determination unit
33 determines, as the monitoring distance, a monitoring
15 distance calculated based on a location or the like of the
obstacle. The monitoring distance determination unit 33
outputs the determined monitoring distance to the
monitoring region determination unit 34. The monitoring
distance determination unit 33 may determine the monitoring
20 distance by using the train location information, the train
speed information, and the like acquired from the train
control device 20. In addition, the monitoring distance
determination unit 33 calculates a recommended train speed,
which is a speed recommended in the train 10, together with
25 the train control device 20 on the basis of the determined
monitoring distance, the braking distance of the train 10,
and the like.
[0017] The monitoring region determination unit 34
determines a monitoring region to be monitored by the
30 sensor 31, by using the monitoring distance acquired from
the monitoring distance determination unit 33. For example,
the monitoring region determination unit 34 adds a first
distance defined in a front-rear direction in the traveling
10
direction of the train 10 to the monitoring distance, adds
a second distance defined in a left-right direction of the
train 10, which is a direction perpendicular to the
traveling direction of the train 10, to the monitoring
5 distance, to determine a region indicated by the added
range as the monitoring region. The monitoring region
determination unit 34 may acquire the train location
information and the train speed information from the train
control device 20 via the monitoring distance determination
10 unit 33, and change the first distance and the second
distance by using the train location information, the train
speed information, and the like. In addition, the
monitoring region determination unit 34 may set a range in
a height direction of the monitoring region. A shape and a
15 range of the monitoring region may be identical or
different on a side closer to the train 10 and a side
farther from the train 10. The monitoring region
determination unit 34 outputs the determined monitoring
region to the sensor 31.
20 [0018] Next, an action of the obstacle detection device
30 will be described. In the present embodiment, the
monitoring distance determination unit 33 acquires the
monitoring region from the monitoring region determination
unit 34, when the monitoring distance is changed based on
25 the detection result or the like acquired from the obstacle
detection unit 32. The monitoring distance determination
unit 33 changes the monitoring distance such that a part of
a monitored first monitoring region overlaps with a part of
a second monitoring region based on the changed monitoring
30 distance, in order not to generate a region not monitored
by the sensor 31 on the route of the train 10. For example,
in a case where the monitoring distance determination unit
33 acquires a detection result indicating that there is a
11
possibility of presence of an obstacle in a region other
than the monitoring region from the obstacle detection unit
32, the monitoring distance determination unit 33
determines the monitoring distance so as to be nearer, that
5 is, shorter than the current monitoring distance, in order
to check whether or not an obstacle is present.
[0019] After shortening the monitoring distance, in a
case where the obstacle is no longer present on the route
of the train 10 as the obstacle has moved or the like, the
10 monitoring distance determination unit 33 returns the
monitoring distance to an original monitoring distance. At
this time, if the monitoring distance determination unit 33
suddenly changes the monitoring distance, there is a
possibility that a region not monitored by the sensor 31
15 may be generated on the route of the train 10. Therefore,
the monitoring distance determination unit 33 changes the
monitoring distance such that a part of a monitored first
monitoring region overlaps with a part of a second
monitoring region based on the changed monitoring distance,
20 in order not to generate the region not monitored by the
sensor 31 on the route of the train 10. Note that the
monitoring distance determination unit 33 assumes that a
size of the monitoring region determined by using a
previous monitoring distance and a size of the monitoring
25 region determined by using a latest monitoring distance
after the change are identical, for the monitoring region
determined by the monitoring region determination unit 34.
Therefore, in a case where the previous monitoring distance
acquired from the monitoring distance determination unit 33
30 is different from the latest monitoring distance, the
monitoring region determination unit 34 determines the
monitoring region such that the size of the monitoring
region determined by using the latest monitoring distance
12
is identical to the size of the monitoring region
determined by using the previous monitoring distance.
[0020] FIG. 2 is a diagram illustrating an example of a
state in which an obstacle 50 is present between the train
5 10 and a monitoring region when the obstacle detection
device 30 according to the first embodiment monitors the
monitoring region. FIG. 2 illustrates a state in which the
obstacle detection device 30 determines that the detected
object may be the obstacle 50, shortens the monitoring
10 distance, and changes the monitoring region from a
monitoring region 40 to a monitoring region 41. FIG. 3 is
a diagram illustrating imagery of a change in monitoring
region when the obstacle detection device 30 according to
the first embodiment changes the monitoring distance. FIG.
15 3 illustrates a state in which the obstacle detection
device 30 changes the monitoring distance as the obstacle
50 is no longer present, and changes the monitoring region
from a monitoring region 41a to a monitoring region 41b, a
monitoring region 41c, a monitoring region 41d, a
20 monitoring region 41e, and a monitoring region 41f in this
order. In FIG. 3, a relationship between the monitoring
regions 41a and 41b is that the monitoring region 41a is a
first monitoring region and the monitoring region 41b is a
second monitoring region. This similarly applies to other
25 adjacent monitoring regions. Note that, in FIGS. 2 and 3,
the traveling direction of the train 10 is a direction from
a lower side to an upper side of the figure. In this
manner, in the obstacle detection device 30, the monitoring
distance determination unit 33 changes the monitoring
30 distance such that a region not monitored by the sensor 31
is not generated on the route of the train 10.
[0021] Note that, as a specific example in which the
monitoring distance determination unit 33 changes the
13
monitoring distance, a case where there is an obstacle
between the train 10 and the monitoring region has been
described, but the present disclosure is not limited
thereto. For example, as described above, the monitoring
5 region includes not only the traveling direction of the
train 10 but also the left-right direction of the train 10.
In this case, the objects detected by the sensor 31 include
structures such as traffic lights and buildings on a
wayside of the route of the train 10, and wayside features
10 that are natural objects such as trees and cliffs on a
wayside of the route of the train 10. In a case where the
obstacle detection unit 32 determines, on the basis of the
monitoring result acquired from the sensor 31, that there
is a certain object in a region other than the monitoring
15 region even if the obstacle or the wayside feature cannot
be specified, the obstacle detection unit 32 may output
information indicating that there is a possibility of
presence of an obstacle or a wayside feature in a region
other than the monitoring region, as a detection result to
20 the train control device 20 and the monitoring distance
determination unit 33. When the monitoring distance
determination unit 33 acquires, from the obstacle detection
unit 32, a detection result indicating that there is a
possibility of presence of an obstacle or a wayside feature
25 in a region other than the monitoring region, the
monitoring distance determination unit 33 may change the
monitoring distance such that a part of a monitored first
monitoring region overlaps with a part of a second
monitoring region based on the changed monitoring distance.
30 [0022] An action of the obstacle detection device 30
according to the present embodiment will be described with
reference to a flowchart. FIG. 4 is a flowchart
illustrating an action of the obstacle detection device 30
14
according to the first embodiment. When the train 10 is
activated, in the obstacle detection device 30, the
monitoring distance determination unit 33 provisionally
determines a monitoring distance (step S101). For example,
5 the monitoring distance determination unit 33 provisionally
determines a predetermined monitoring distance as the
monitoring distance. The monitoring distance determination
unit 33 outputs the provisionally determined monitoring
distance to the monitoring region determination unit 34.
10 The monitoring region determination unit 34 provisionally
determines a monitoring region by using the provisionally
determined monitoring distance (step S102). For example,
the monitoring region determination unit 34 provisionally
determines the monitoring region by adding a predetermined
15 distance to the provisionally determined monitoring
distance. The monitoring region determination unit 34
outputs the provisionally determined monitoring region to
the sensor 31.
[0023] The sensor 31 performs monitoring in the
20 monitoring region acquired from the monitoring region
determination unit 34 (step S103). Immediately after
activation of the train 10, the sensor 31 cannot acquire
the monitoring region based on the above-described method
from the monitoring region determination unit 34.
25 Therefore, immediately after activation of the train 10,
the sensor 31 performs monitoring in the provisionally
determined monitoring region. The sensor 31 outputs a
monitoring result to the obstacle detection unit 32. The
obstacle detection unit 32 determines presence or absence
30 of an obstacle on the basis of the monitoring result
acquired from the sensor 31 (step S104). When there is an
obstacle (step S104: Yes), the obstacle detection unit 32
outputs a detection result indicating that an obstacle has
15
been detected, to the train control device 20 and the
monitoring distance determination unit 33 (step S105).
When there is no obstacle (step S104: No), the obstacle
detection unit 32 outputs a detection result indicating
5 that no obstacle has been detected, to the train control
device 20 and the monitoring distance determination unit 33
(step S106).
[0024] The monitoring distance determination unit 33
determines a monitoring distance by using the detection
10 result acquired from the obstacle detection unit 32 (step
S107). The monitoring distance determination unit 33
outputs the determined monitoring distance to the
monitoring region determination unit 34. In addition, the
monitoring distance determination unit 33 calculates a
15 recommended train speed of the train 10 together with the
train control device 20, by using the detection result
acquired from the obstacle detection unit 32 (step S108).
Note that the monitoring distance determination unit 33 may
change the order of the actions in steps S107 and S108, or
20 may perform the actions in parallel. The monitoring region
determination unit 34 determines a monitoring region by
using the monitoring distance acquired from the monitoring
distance determination unit 33 (step S109). The monitoring
region determination unit 34 outputs the determined
25 monitoring region to the sensor 31.
[0025] The obstacle detection device 30 determines
whether or not the operation of the train 10 has ended
(step S110). When the operation of the train 10 has not
ended (step S110: No), the obstacle detection device 30
30 returns to step S103 and repeats the above-described action.
When the operation of the train 10 has ended (step S110:
Yes), the obstacle detection device 30 ends the action.
[0026] Next, a hardware configuration of the obstacle
16
detection device 30 will be described. In the obstacle
detection device 30, the sensor 31 is a measuring
instrument such as a stereo camera or a LIDAR as described
above. The obstacle detection unit 32, the monitoring
5 distance determination unit 33, and the monitoring region
determination unit 34 are implemented by processing
circuitry. The processing circuitry may be a memory and a
processor that executes a program stored in the memory, or
may be dedicated hardware.
10 [0027] FIG. 5 is a diagram illustrating an example of a
case where the processing circuitry included in the
obstacle detection device 30 according to the first
embodiment is configured with a processor and a memory. In
a case where the processing circuitry is configured with a
15 processor 91 and a memory 92, each function of the
processing circuitry of the obstacle detection device 30 is
implemented by software, firmware, or a combination of
software and firmware. The software or the firmware is
described as a program and stored in the memory 92. In the
20 processing circuitry, the processor 91 reads and executes
the program stored in the memory 92 to implement each
function. That is, the processing circuitry includes the
memory 92 for storage of a program by which processing of
the obstacle detection device 30 is executed as a result.
25 It can also be said that these programs cause a computer to
execute a procedure and a method of the obstacle detection
device 30.
[0028] Here, the processor 91 may be a central
processing unit (CPU), a processing device, an arithmetic
30 device, a microprocessor, a microcomputer, a digital signal
processor (DSP), or the like. Further, the memory 92
corresponds to a nonvolatile or volatile semiconductor
memory such as a random access memory (RAM), a read only
17
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 disk, a mini disk, or a digital versatile
5 disc (DVD).
[0029] FIG. 6 is a diagram illustrating an example of a
case where the processing circuitry included in the
obstacle detection device 30 according to the first
embodiment is configured with dedicated hardware. In a
10 case where the processing circuitry is configured with
dedicated hardware, processing circuitry 93 illustrated in
FIG. 6 corresponds to, for example, a single circuit, a
composite circuit, a programmed processor, a parallelprogrammed processor, an application specific integrated
15 circuit (ASIC), a field programmable gate array (FPGA), or
a combination thereof. Individual functions of the
obstacle detection device 30 may be implemented by the
processing circuitry 93 for each function, or the
individual functions may be collectively implemented by the
20 processing circuitry 93.
[0030] Note that some of the individual functions of the
obstacle detection device 30 may be implemented by
dedicated hardware, and some of the individual functions
may be implemented by software or firmware. In this manner,
25 the processing circuitry can implement the individual
functions described above by dedicated hardware, software,
firmware, or a combination thereof.
[0031] As described above, according to the present
embodiment, in the obstacle detection device 30, the
30 monitoring distance determination unit 33 acquires the
monitoring region from the monitoring region determination
unit 34 when the monitoring distance is changed by using
the detection result acquired from the obstacle detection
18
unit 32, and changes the monitoring distance such that a
part of a monitored first monitoring region overlaps with a
part of a second monitoring region based on the changed
monitoring distance, in order not to generate a region not
5 monitored by the sensor 31 on the route of the train 10.
As a result, the obstacle detection device 30 can change
the monitoring distance without missing an obstacle on the
route of the train 10.
[0032] Second Embodiment.
10 In a second embodiment, an obstacle detection device
determines a monitoring distance in consideration of a
monitorable region of the sensor 31 under a current
monitoring condition.
[0033] FIG. 7 is a diagram illustrating a configuration
15 example of a train 10a including an obstacle detection
device 30a according to the second embodiment. The train
10a includes the train control device 20 and the obstacle
detection device 30a. During operation, the train 10a
monitors whether or not there is an obstacle on a route by
20 using the obstacle detection device 30a. The obstacle
detection device 30a is installed on the train 10a and
monitors whether or not there is an obstacle on the route
of the train 10a. The obstacle detection device 30a
includes the sensor 31, the obstacle detection unit 32, a
25 monitoring distance determination unit 33a, the monitoring
region determination unit 34, and a monitorable region
determination unit 35. The monitorable region
determination unit 35 includes an unshielded-region
determination unit 36 and a monitorable distance
30 determination unit 37.
[0034] The unshielded-region determination unit 36
determines an unshielded region, which is not subjected to
monitoring interference by a shielding object, which is an
19
object other than an obstacle and hinders monitoring of the
sensor 31 at a location other than the route of the train
10a. The shielding object is, for example, a structure on
a wayside of the route of the train 10a or a wayside
5 feature such as a natural object on a wayside of the route
of the train 10a. For example, the unshielded-region
determination unit 36 holds 3D map information on wayside
features, and determines the unshielded region by using the
3D map information and train location information of the
10 train 10a acquired from the train control device 20 or the
monitoring distance determination unit 33a. Furthermore,
in a case where the sensor 31 is a measuring instrument
that uses a reflected wave of a laser with a laser sensor
or the like, the unshielded-region determination unit 36
15 may determine the unshielded region on the basis of
presence or absence of the reflected wave from the laser.
For example, in a monitoring result of monitoring the
monitoring region by the sensor 31, the unshielded-region
determination unit 36 can determine that there is no object
20 in a region where the reflected wave of the laser has not
returned, and regard as the unshielded region. Furthermore,
in a case where the sensor 31 is a stereo camera, the
unshielded-region determination unit 36 may create a
disparity map, calculate a distance, and determine the
25 unshielded region. Further, when there are a plurality of
shielding objects having a columnar shape in front on the
route of the train 10a, the unshielded-region determination
unit 36 may generate a largest convex closure inscribed in
a region that is not shielded, and set the generated convex
30 closure as the unshielded region, since a monitoring state
is unstable even if a longer distance than the shielding
object is partially seen.
[0035] The monitorable distance determination unit 37
20
determines a monitorable distance, which is a distance that
can be monitored by the sensor 31 under a current
monitoring condition. In a case where the sensor 31 is a
measuring instrument such as a stereo camera or LIDAR as
5 described above, the monitorable distance is affected by
weather conditions, for example, fog, storm, and the like.
Therefore, the monitorable distance determination unit 37
determines the monitorable distance on the basis of the
monitoring result acquired from the sensor 31. For example,
10 in a case where a mast located on a wayside of the route of
the train 10a can be detected in the monitoring result, the
monitorable distance determination unit 37 can estimate the
monitorable distance from an average interval between the
masts based on the number of masts that can be detected.
15 In addition, the monitorable distance determination unit 37
may acquire weather information or the like of a region
where the train 10a travels, from an external network or
the like (not illustrated), and use the information for
determination of the monitorable distance.
20 [0036] The monitorable region determination unit 35
determines the monitorable region of the sensor 31 under a
current monitoring condition on the basis of the unshielded
region determined by the unshielded-region determination
unit 36 and the monitorable distance determined by the
25 monitorable distance determination unit 37. The
monitorable region determination unit 35 outputs the
determined monitorable region to the monitoring distance
determination unit 33a.
[0037] The monitoring distance determination unit 33a
30 determines the monitoring distance within a range of the
monitorable region determined by the monitorable region
determination unit 35. For example, in a case where a
monitorable region of the sensor 31 under a previous
21
monitoring condition and a monitorable region of the sensor
31 under a current monitoring condition are different, the
monitorable regions being determined by the monitorable
region determination unit 35, the monitoring distance
5 determination unit 33a changes the monitoring distance such
that a part of the first monitoring region overlaps with a
part of the second monitoring region.
[0038] FIG. 8 is a diagram illustrating a state in which
the monitoring distance determination unit 33a of the
10 obstacle detection device 30a according to the second
embodiment shortens the monitoring distance as a shielding
object is present. FIG. 8 illustrates a state in which the
obstacle detection device 30a changes the monitoring region
from the monitoring region 40 to the monitoring region 41
15 when the monitorable region is narrowed as indicated by a
monitorable region 61a by a tunnel 60 which is a shielding
object. FIG. 9 is a diagram illustrating imagery of a
change in monitoring distance when the monitoring distance
determination unit 33a of the obstacle detection device 30a
20 according to the second embodiment returns the monitoring
distance to an original state as the shielding object is no
longer present. FIG. 9 illustrates a state in which the
obstacle detection device 30a changes the monitoring
distance as the monitorable region becomes an original
25 monitorable region 61b as the tunnel 60 as a shielding
object is passed, and the obstacle detection device 30a
changes the monitoring region from the monitoring region
41a to the monitoring region 41b, the monitoring region 41c,
the monitoring region 41d, the monitoring region 41e, and
30 the monitoring region 41f in this order. Note that, in
FIGS. 8 and 9, a traveling direction of the train 10a is a
direction from a lower left side to an upper right side of
the figure. In this manner, in the obstacle detection
22
device 30a, the monitoring distance determination unit 33a
changes the monitoring distance such that a region not
monitored by the sensor 31 is not generated on the route of
the train 10a.
5 [0039] An action of the obstacle detection device 30a of
the present embodiment will be described with reference to
a flowchart. FIG. 10 is a flowchart illustrating an action
of the obstacle detection device 30a according to the
second embodiment. Note that descriptions of parts similar
10 to the action of the obstacle detection device 30 of the
first embodiment will be simplified. When the train 10a is
activated, in the obstacle detection device 30a, the
monitoring distance determination unit 33a provisionally
determines a monitoring distance (step S201). The
15 monitoring region determination unit 34 provisionally
determines a monitoring region by using the provisionally
determined monitoring distance (step S202). The sensor 31
performs monitoring in the monitoring region acquired from
the monitoring region determination unit 34 (step S203).
20 The sensor 31 outputs a monitoring result to the obstacle
detection unit 32 and the monitorable region determination
unit 35.
[0040] The obstacle detection unit 32 determines
presence or absence of an obstacle on the basis of the
25 monitoring result acquired from the sensor 31 (step S204).
When there is an obstacle (step S204: Yes), the obstacle
detection unit 32 outputs a detection result indicating
that an obstacle has been detected, to the train control
device 20 and the monitoring distance determination unit
30 33a (step S205). When there is no obstacle (step S204: No),
the obstacle detection unit 32 outputs a detection result
indicating that no obstacle has been detected, to the train
control device 20 and the monitoring distance determination
23
unit 33a (step S206).
[0041] The unshielded-region determination unit 36
determines an unshielded region that is not subjected to
monitoring interference by a shielding object at a location
5 other than the route of the train 10a (step S207). The
monitorable distance determination unit 37 determines a
monitorable distance by the sensor 31 under a current
monitoring condition (step S208). The monitorable region
determination unit 35 determines a monitorable region on
10 the basis of the unshielded region determined by the
unshielded-region determination unit 36 and the monitorable
distance determined by the monitorable distance
determination unit 37 (step S209). The monitorable region
determination unit 35 outputs the determined monitorable
15 region to the monitoring distance determination unit 33a.
[0042] The monitoring distance determination unit 33a
determines a monitoring distance by using the detection
result acquired from the obstacle detection unit 32 and the
monitorable region acquired from the monitorable region
20 determination unit 35 (step S210). In addition, the
monitoring distance determination unit 33a calculates a
recommended train speed of the train 10a together with the
train control device 20, by using the detection result
acquired from the obstacle detection unit 32 and the
25 monitorable region acquired from the monitorable region
determination unit 35 (step S211). Note that the
monitoring distance determination unit 33a may change the
order of the actions in steps S210 and S211, or may perform
the actions in parallel. The monitoring region
30 determination unit 34 determines a monitoring region by
using the monitoring distance acquired from the monitoring
distance determination unit 33a (step S212). The
monitoring region determination unit 34 outputs the
24
monitoring region to the sensor 31.
[0043] The obstacle detection device 30a determines
whether or not the operation of the train 10a has ended
(step S213). When the operation of the train 10a has not
5 ended (step S213: No), the obstacle detection device 30a
returns to step S203 and repeats the above-described action.
When the operation of the train 10a has ended (step S213:
Yes), the obstacle detection device 30a ends the action.
[0044] Regarding a hardware configuration of the
10 obstacle detection device 30a, the monitoring distance
determination unit 33a and the monitorable region
determination unit 35 are implemented by processing
circuitry. The processing circuitry may be a memory and a
processor that executes a program stored in the memory, or
15 may be dedicated hardware.
[0045] As described above, according to the present
embodiment, in the obstacle detection device 30a, the
monitoring distance determination unit 33a determines the
monitoring distance by using the monitoring result and the
20 monitorable region. As a result, in addition to the
effects of the first embodiment, the obstacle detection
device 30a can avoid unnecessary monitoring, by monitoring
in a monitorable region without monitoring a long distance
in a state where the sensor 31 cannot monitor a long
25 distance.
[0046] Third Embodiment.
In a third embodiment, an obstacle detection device
determines a monitoring distance so as to track an obstacle
detected by the obstacle detection unit 32.
30 [0047] FIG. 11 is a diagram illustrating a configuration
example of a train 10b including an obstacle detection
device 30b according to the third embodiment. The train
10b includes the train control device 20 and the obstacle
25
detection device 30b. During operation, the train 10b
monitors whether or not there is an obstacle on a route by
using the obstacle detection device 30b. The obstacle
detection device 30b is installed on the train 10b and
5 monitors whether or not there is an obstacle on the route
of the train 10b. The obstacle detection device 30b
includes the sensor 31, the obstacle detection unit 32, a
monitoring distance determination unit 33b, a monitoring
region determination unit 34b, and an obstacle tracking
10 unit 38. In the third embodiment, the obstacle detection
unit 32 outputs a detection result to the train control
device 20, the monitoring distance determination unit 33b,
and the obstacle tracking unit 38.
[0048] The obstacle tracking unit 38 uses a time-series
15 detection result of the obstacle detected by the obstacle
detection unit 32, to track the detected obstacle in
association. The obstacle tracking unit 38 outputs
tracking information indicating a location of the obstacle,
to the monitoring distance determination unit 33b and the
20 monitoring region determination unit 34b. The obstacle
tracking unit 38 may include information such as a size and
a shape of the obstacle and a moving speed of the obstacle,
in the tracking information.
[0049] The monitoring distance determination unit 33b
25 determines a monitoring distance by using the detection
result acquired from the obstacle detection unit 32 and the
tracking information acquired from the obstacle tracking
unit 38. For example, the monitoring distance
determination unit 33b determines, as the monitoring
30 distance, a distance from the train 10b to the location of
the obstacle indicated by the tracking information. In a
case where the obstacle is not moving, in a case where the
obstacle is moving away at a speed lower than a speed of
26
the train 10b, or in a case where the obstacle is moving
toward the train 10b, the monitoring distance determination
unit 33b changes the monitoring distance to be short.
[0050] The monitoring region determination unit 34b
5 determines a monitoring region by using the monitoring
distance acquired from the monitoring distance
determination unit 33b and the tracking information
acquired from the obstacle tracking unit 38. The
monitoring region determination unit 34b may change a size
10 of the monitoring region in accordance with the distance
between the train 10b and the obstacle, and may change a
size, a shape, and the like of the monitoring region in
accordance with a size, a shape, and the like of the
obstacle when the tracking information includes information
15 of the size, the shape, and the like of the obstacle.
[0051] FIG. 12 is a diagram illustrating a locational
relationship between the train 10b and a monitoring region
based on a monitoring distance determined when there is no
obstacle by the monitoring distance determination unit 33b
20 of the obstacle detection device 30b according to the third
embodiment. FIG. 12 illustrates a state in which the
obstacle detection device 30b monitors the monitoring
region 41 based on a constant monitoring distance when
there is no obstacle. FIG. 13 is a diagram illustrating a
25 locational relationship between the train 10b and a
monitoring region based on a monitoring distance determined
at a time of obstacle tracking by the monitoring distance
determination unit 33b of the obstacle detection device 30b
according to the third embodiment. FIG. 13 illustrates a
30 state in which a distance between the train 10b and the
monitoring region 41 is becoming shorter as the obstacle
detection device 30b has changed the monitoring distance in
accordance with a location of the obstacle 50. Note that,
27
in FIGS. 12 and 13, a traveling direction of the train 10b
is a direction from a right side to a left side of the
figure. Also in such a case, in the obstacle detection
device 30b, the monitoring distance determination unit 33b
5 changes the monitoring distance such that a region not
monitored by the sensor 31 is not generated on the route of
the train 10b. That is, also when the distance between the
train 10b and the obstacle 50 is changed in the obstacle
tracking unit 38, the monitoring distance determination
10 unit 33b changes the monitoring distance such that a part
of the first monitoring region overlaps with a part of the
second monitoring region.
[0052] An action of the obstacle detection device 30b of
the present embodiment will be described with reference to
15 a flowchart. FIG. 14 is a flowchart illustrating an action
of the obstacle detection device 30b according to the third
embodiment. Note that descriptions of parts similar to the
action of the obstacle detection device 30 of the first
embodiment will be simplified. When the train 10b is
20 activated, in the obstacle detection device 30b, the
monitoring distance determination unit 33b provisionally
determines a monitoring distance (step S301). The
monitoring region determination unit 34b provisionally
determines a monitoring region by using the provisionally
25 determined monitoring distance (step S302). The sensor 31
performs monitoring in the monitoring region acquired from
the monitoring region determination unit 34b (step S303).
[0053] The obstacle detection unit 32 determines
presence or absence of an obstacle on the basis of a
30 monitoring result acquired from the sensor 31 (step S304).
When there is an obstacle (step S304: Yes), the obstacle
detection unit 32 outputs a detection result indicating
that an obstacle has been detected, to the train control
28
device 20, the monitoring distance determination unit 33b,
and the obstacle tracking unit 38 (step S305). When there
is no obstacle (step S304: No), the obstacle detection unit
32 outputs a detection result indicating that no obstacle
5 has been detected, to the train control device 20, the
monitoring distance determination unit 33b, and the
obstacle tracking unit 38 (step S306).
[0054] The obstacle tracking unit 38 uses a time-series
detection result of the obstacle detected by the obstacle
10 detection unit 32, to track the detected obstacle in
association (step S307). The obstacle tracking unit 38
outputs tracking information to the monitoring distance
determination unit 33b and the monitoring region
determination unit 34b.
15 [0055] The monitoring distance determination unit 33b
determines a monitoring distance by using the detection
result acquired from the obstacle detection unit 32 and the
tracking information acquired from the obstacle tracking
unit 38 (step S308). In addition, the monitoring distance
20 determination unit 33b calculates a recommended train speed
of the train 10b together with the train control device 20
by using the detection result acquired from the obstacle
detection unit 32 and the tracking information acquired
from the obstacle tracking unit 38 (step S309). Note that
25 the monitoring distance determination unit 33b may change
the order of the actions in steps S308 and S309, or may
perform the actions in parallel. The monitoring region
determination unit 34b determines a monitoring region by
using the monitoring distance acquired from the monitoring
30 distance determination unit 33b and the tracking
information acquired from the obstacle tracking unit 38
(step S310).
[0056] The obstacle detection device 30b determines
29
whether or not the operation of the train 10b has ended
(step S311). When the operation of the train 10b has not
ended (step S311: No), the obstacle detection device 30b
returns to step S303 and repeats the above-described action.
5 When the operation of the train 10b has ended (step S311:
Yes), the obstacle detection device 30b ends the action.
[0057] Regarding a hardware configuration of the
obstacle detection device 30b, the obstacle tracking unit
38 is implemented by processing circuitry. The processing
10 circuitry may be a memory and a processor that executes a
program stored in the memory, or may be dedicated hardware.
[0058] As described above, according to the present
embodiment, in the obstacle detection device 30b, the
monitoring distance determination unit 33b determines the
15 monitoring distance by using the monitoring result and the
tracking information. As a result, in addition to the
effects of the first embodiment, the obstacle detection
device 30b can further perform monitoring according to a
state of the obstacle.
20 [0059] Fourth Embodiment.
In a fourth embodiment, an obstacle detection device
determines a monitoring distance so as to track an obstacle
detected by the obstacle detection unit 32, in
consideration of a monitorable region of the sensor 31
25 under a current monitoring condition.
[0060] FIG. 15 is a diagram illustrating a configuration
example of a train 10c including an obstacle detection
device 30c according to the fourth embodiment. The train
10c includes the train control device 20 and the obstacle
30 detection device 30c. During operation, the train 10c
monitors whether or not there is an obstacle on a route by
using the obstacle detection device 30c. The obstacle
detection device 30c is installed on the train 10c and
30
monitors whether or not there is an obstacle on the route
of the train 10c. The obstacle detection device 30c
includes the sensor 31, the obstacle detection unit 32, a
monitoring distance determination unit 33c, the monitoring
5 region determination unit 34b, the monitorable region
determination unit 35, and the obstacle tracking unit 38.
In the fourth embodiment, an action of the monitorable
region determination unit 35 is similar to the action of
the monitorable region determination unit 35 of the second
10 embodiment. An action of the obstacle tracking unit 38 is
similar to the action of the obstacle tracking unit 38
according to the third embodiment.
[0061] The monitoring distance determination unit 33c
has both the function of the monitoring distance
15 determination unit 33a of the second embodiment and the
function of the monitoring distance determination unit 33b
of the third embodiment. That is, the monitoring distance
determination unit 33c determines a monitoring distance by
using a detection result acquired from the obstacle
20 detection unit 32 and tracking information acquired from
the obstacle tracking unit 38, within a range of a
monitorable region determined by the monitorable region
determination unit 35.
[0062] An action of the obstacle detection device 30c of
25 the present embodiment will be described with reference to
a flowchart. FIG. 16 is a flowchart illustrating an action
of the obstacle detection device 30c according to the
fourth embodiment. Note that descriptions of parts similar
to the action of the obstacle detection device 30 of the
30 first embodiment will be simplified. When the train 10c is
activated, in the obstacle detection device 30c, the
monitoring distance determination unit 33c provisionally
determines a monitoring distance (step S401). The
31
monitoring region determination unit 34b provisionally
determines a monitoring region by using the provisionally
determined monitoring distance (step S402). The sensor 31
performs monitoring in the monitoring region acquired from
5 the monitoring region determination unit 34b (step S403).
The sensor 31 outputs a monitoring result to the obstacle
detection unit 32 and the monitorable region determination
unit 35.
[0063] The obstacle detection unit 32 determines
10 presence or absence of an obstacle on the basis of the
monitoring result acquired from the sensor 31 (step S404).
When there is an obstacle (step S404: Yes), the obstacle
detection unit 32 outputs a detection result indicating
that an obstacle has been detected, to the train control
15 device 20, the monitoring distance determination unit 33c,
and the obstacle tracking unit 38 (step S405). When there
is no obstacle (step S404: No), the obstacle detection unit
32 outputs a detection result indicating that no obstacle
has been detected, to the train control device 20, the
20 monitoring distance determination unit 33c, and the
obstacle tracking unit 38 (step S406).
[0064] The unshielded-region determination unit 36
determines an unshielded region that is not subjected to
monitoring interference by a shielding object at a location
25 other than the route of the train 10c (step S407). The
monitorable distance determination unit 37 determines a
monitorable distance by the sensor 31 under a current
monitoring condition (step S408). The monitorable region
determination unit 35 determines a monitorable region on
30 the basis of the unshielded region determined by the
unshielded-region determination unit 36 and the monitorable
distance determined by the monitorable distance
determination unit 37 (step S409). The monitorable region
32
determination unit 35 outputs the determined monitorable
region to the monitoring distance determination unit 33c.
[0065] The obstacle tracking unit 38 uses a time-series
detection result of the obstacle detected by the obstacle
5 detection unit 32, to track the detected obstacle in
association (step S410). The obstacle tracking unit 38
outputs tracking information to the monitoring distance
determination unit 33c and the monitoring region
determination unit 34b.
10 [0066] By using the detection result acquired from the
obstacle detection unit 32, the monitorable region acquired
from the monitorable region determination unit 35, and the
tracking information acquired from the obstacle tracking
unit 38, the monitoring distance determination unit 33c
15 determines a monitoring distance (step S411). In addition,
by using the detection result acquired from the obstacle
detection unit 32, the monitorable region acquired from the
monitorable region determination unit 35, and the tracking
information acquired from the obstacle tracking unit 38,
20 the monitoring distance determination unit 33c calculates a
recommended train speed of the train 10c together with the
train control device 20 (step S412). Note that the
monitoring distance determination unit 33c may change the
order of the actions in steps S411 and S412, or may perform
25 the actions in parallel. The monitoring region
determination unit 34b determines a monitoring region by
using the monitoring distance acquired from the monitoring
distance determination unit 33c and the tracking
information acquired from the obstacle tracking unit 38
30 (step S413). The monitoring region determination unit 34b
outputs the monitoring region to the sensor 31.
[0067] The obstacle detection device 30c determines
whether or not the operation of the train 10c has ended
33
(step S414). When the operation of the train 10c has not
ended (step S414: No), the obstacle detection device 30c
returns to step S403 and repeats the above-described action.
When the operation of the train 10c has ended (step S414:
5 Yes), the obstacle detection device 30c ends the action.
[0068] As described above, according to the present
embodiment, in the obstacle detection device 30c, the
monitoring distance determination unit 33c determines the
monitoring distance by using the monitoring result, the
10 monitorable region, and the tracking information. As a
result, in addition to the effects of the first embodiment,
the obstacle detection device 30c can perform monitoring
according to a state of an obstacle while avoiding
unnecessary monitoring, by monitoring in a monitorable
15 region without monitoring a long distance in a state where
the sensor 31 cannot monitor a long distance.
[0069] The configurations illustrated in the above
embodiments illustrate one example and can be combined with
another known technique, and it is also possible to combine
20 embodiments with each other and omit and change a part of
the configuration without departing from the subject matter
of the present disclosure.
Reference Signs List
25 [0070] 10, 10a, 10b, 10c train; 20 train control
device; 30, 30a, 30b, 30c obstacle detection device; 31
sensor; 32 obstacle detection unit; 33, 33a, 33b, 33c
monitoring distance determination unit; 34, 34b monitoring
region determination unit; 35 monitorable region
30 determination unit; 36 unshielded-region determination
unit; 37 monitorable distance determination unit; 38
obstacle tracking unit; 40, 41, 41a to 41f monitoring
region; 50 obstacle; 60 tunnel; 61a, 61b monitorable
34
region.

35
WE CLAIM:
1. An obstacle detection device to be installed on a
train, the obstacle detection device comprising:
a sensor to monitor a monitoring region and output a
5 monitoring result;
an obstacle detection unit to determine presence or
absence of an obstacle on a route of the train based on the
monitoring result, and output a detection result;
a monitoring distance determination unit to use the
10 detection result to determine a monitoring distance from
the train to a reference for monitoring by the sensor in
front of the train; and
a monitoring region determination unit to use the
monitoring distance to determine the monitoring region to
15 be monitored by the sensor, wherein
when changing the monitoring distance, the monitoring
distance determination unit acquires the monitoring region
from the monitoring region determination unit, and changes
the monitoring distance such that a part of a first
20 monitoring region that has been monitored overlaps with a
part of a second monitoring region based on the changed
monitoring distance, in order not to generate a region that
is not monitored by the sensor on a route of the train.
25 2. The obstacle detection device according to claim 1,
comprising:
a monitorable region determination unit to determine a
monitorable region of the sensor under a current monitoring
condition, wherein
30 the monitoring distance determination unit determines
the monitoring distance within a range of the monitorable
region determined by the monitorable region determination
unit.
36
3. The obstacle detection device according to claim 2,
wherein
the monitorable region determination unit includes:
5 an unshielded-region determination unit to determine
an unshielded region that is not subjected to monitoring
interference by a shielding object, the shielding object
being an object other than the obstacle and hindering
monitoring of the sensor at a location other than a route
10 of the train; and
a monitorable distance determination unit to determine
a monitorable distance that is a distance that can be
monitored by the sensor under the current monitoring
condition.
15
4. The obstacle detection device according to claim 2 or
3, wherein
in a case where a monitorable region of the sensor
under a previous monitoring condition and a monitorable
20 region of the sensor under the current monitoring condition
are different, the monitorable regions being determined by
the monitorable region determination unit, the monitoring
distance determination unit changes the monitoring distance
such that a part of the first monitoring region overlaps
25 with a part of the second monitoring region.
5. The obstacle detection device according to any one of
claims 1 to 4, comprising:
an obstacle tracking unit to use a time-series
30 detection result of the obstacle detected by the obstacle
detection unit to track the detected obstacle in
association, and output tracking information indicating a
location of the obstacle, wherein
37
the monitoring distance determination unit determines
the monitoring distance by using the detection result and
the tracking information.
5 6. The obstacle detection device according to claim 5,
wherein
when a distance between the train and the obstacle is
changed in the obstacle tracking unit, the monitoring
distance determination unit changes the monitoring distance
10 such that a part of the first monitoring region overlaps
with a part of the second monitoring region.
7. The obstacle detection device according to any one of
claims 1 to 6, wherein
15 the monitoring distance determination unit calculates
a recommended train speed that is a speed recommended in
the train together with a train control device that
controls traveling of the train, based on the monitoring
distance and a braking distance of the train.
20
8. An obstacle detection method for an obstacle detection
device to be installed on a train, the obstacle detection
method comprising:
a step of performing monitoring, by a sensor, to
25 monitor a monitoring region and output a monitoring result;
a step of performing obstacle detection, by an
obstacle detection unit, to determine presence or absence
of an obstacle on a route of the train based on the
monitoring result, and output a detection result;
30 a step of performing monitoring distance determination,
by a monitoring distance determination unit, to use the
detection result to determine a monitoring distance from
the train to a reference for monitoring by the sensor in
38
front of the train; and
a step of performing monitoring region determination,
by a monitoring region determination unit, to use the
monitoring distance to determine the monitoring region to
5 be monitored by the sensor, wherein
in the step of performing monitoring distance
determination, when changing the monitoring distance, the
monitoring distance determination unit acquires the
monitoring region from the monitoring region determination
10 unit, and changes the monitoring distance such that a part
of a first monitoring region that has been monitored
overlaps with a part of a second monitoring region based on
the changed monitoring distance, in order not to generate a
region that is not monitored by the sensor on a route of
15 the train.
9. The obstacle detection method according to claim 8,
comprising:
a step of performing monitorable region determination,
20 by a monitorable region determination unit, to determine a
monitorable region of the sensor under a current monitoring
condition, wherein
in the step of performing monitoring distance
determination, the monitoring distance determination unit
25 determines the monitoring distance within a range of the
monitorable region determined by the monitorable region
determination unit.
10. The obstacle detection method according to claim 9,
30 wherein
the monitorable region determination unit includes an
unshielded-region determination unit and a monitorable
distance determination unit, and
39
the step of performing monitorable region
determination includes:
a step of performing unshielded-region determination,
by the unshielded-region determination unit, to determine
5 an unshielded region that is not subjected to monitoring
interference by a shielding object, the shielding object
being an object other than the obstacle and hindering
monitoring of the sensor at a location other than a route
of the train; and
10 a step of performing monitorable distance
determination, by the monitorable distance determination
unit, to determine a monitorable distance that is a
distance that can be monitored by the sensor under the
current monitoring condition.
15
11. The obstacle detection method according to claim 9 or
10, wherein
in the step of performing monitoring distance
determination, in a case where a monitorable region of the
20 sensor under a previous monitoring condition and a
monitorable region of the sensor under the current
monitoring condition are different, the monitorable regions
being determined by the monitorable region determination
unit, the monitoring distance determination unit changes
25 the monitoring distance such that a part of the first
monitoring region overlaps with a part of the second
monitoring region.
12. The obstacle detection method according to any one of
30 claims 8 to 11, comprising:
a step of performing obstacle tracking, by an obstacle
tracking unit, to use a time-series detection result of the
obstacle detected by the obstacle detection unit to track
40
the detected obstacle in association, and output tracking
information indicating a location of the obstacle, wherein
in the step of performing monitoring distance
determination, the monitoring distance determination unit
5 determines the monitoring distance by using the detection
result and the tracking information.
13. The obstacle detection method according to claim 12,
wherein
10 in the step of performing monitoring distance
determination, when a distance between the train and the
obstacle is changed in the obstacle tracking unit, the
monitoring distance determination unit changes the
monitoring distance such that a part of the first
15 monitoring region overlaps with a part of the second
monitoring region.
14. The obstacle detection method according to any one of
claims 8 to 13, comprising:
20 a step of performing recommended train speed
calculation, by the monitoring distance determination unit,
to calculate a recommended train speed that is a speed
recommended in the train together with a train control
device that controls traveling of the train, based on the
25 monitoring distance and a braking distance of the train.