(EXTRACTED FROM WIPO)

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
WHEEL TREAD ROUGHNESS ESTIMATION DEVICE AND WHEEL TREAD
ROUGHNESS ESTIMATION METHOD;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED
AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-
3, MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
TITLE OF THE INVENTION:
WHEEL TREAD ROUGHNESS ESTIMATION DEVICE AND WHEEL TREAD
5 ROUGHNESS ESTIMATION METHOD
Field
[0001] The present disclosure relates to a wheel tread
roughness estimation device and a wheel tread roughness
10 estimation method intended for wheel treads of railway
vehicles.
Background
[0002] A regenerative brake and an air brake (or
15 pneumatic brake) have been used in combination as brakes
for a railway vehicle, with the regenerative brake mainly
used under normal conditions. The air brake is used for
only tens of milliseconds until the regenerative brake
starts or to prevent a stopping railway vehicle from
20 rolling to move. In order to provide an immediate braking
effect during regenerative braking of the railway vehicle,
the air brake is placed in a precharge state by being
operated with a precharge brake cylinder (BC) pressure. In
cases where a tread brake device is used as the air brake,
25 a pressing position in the precharge state is where a
friction material is in light contact with a wheel tread of
the railway vehicle. Therefore, surface roughness of the
wheel tread decreases, causing the wheel tread to become a
mirror surface. When wheel treads become mirror surfaces,
30 problems arise, including insufficient adhesion that
results in a slide when the air brake is operated for the
railway vehicle with a high speed or insufficient
decelerating to bring to a specified deceleration when
3
emergency braking is operated for the railway vehicle in an
emergency state, or the like. In general, even during
normal running of the railway vehicle, friction between a
rail surface and the wheel tread may decrease the surface
5 roughness of the wheel tread, so that the wheel tread
advances to become the mirror surface and causes similar
problems. Therefore, when the wheel tread of the railway
vehicle becomes the mirror surface, wheel tread roughening
is required, using a tread brake, namely the air brake that
10 presses the friction material against the wheel tread.
[0003] Accurate roughening control for the railway
vehicle requires accurate information on the wheel tread
roughness. For example, Patent Literature 1 discloses a
technique for a wheel measurement device to measure a wheel
15 profile (or a wheel shape) of a railway vehicle running on
a rail by directing a line beam to a wheel from a line
illumination unit, capturing an image of reflected light of
the line beam, and processing the captured image.
20 Citation List
Patent Literature
[0004] Patent Literature 1: Japanese Patent Application
Laid-open No. 2006-118912
25 Summary of Invention
Problem to be solved by the Invention
[0005] However, the above conventional technique
requires installation of a high-accuracy sensor near
wheels. Therefore, a measurement result may be
30 significantly influenced by vibration of the running
railway vehicle, leading to a problematic decrease in
accuracy.
[0006] The present disclosure has been made in view of
4
the above, and an object of the present disclosure is to
obtain a wheel tread roughness estimation device capable of
accurate estimation of wheel tread roughness without being
affected by vibration of a railway vehicle even during
5 running.
Means to Solve the Problem
[0007] In order to solve the above problem and achieve
the object, a wheel tread roughness estimation device
10 according to the present disclosure includes: a driving
information acquisition unit to obtain driving information
of a railway vehicle; a vehicle information acquisition
unit to obtain vehicle information of the railway vehicle
in service; a wheel tread roughness computation unit to
15 determine a set value on a basis of the driving information
and the vehicle information and compute an up-to-date wheel
tread roughness by adding the set value to a preceding
wheel tread roughness indicating a previously computed
roughness of a wheel tread; and an output unit to output
20 the up-to-date wheel tread roughness computed by the wheel
tread roughness computation unit as wheel tread roughness
information.
Effect of the Invention
25 [0008] The wheel tread roughness estimation device
according to the present disclosure has an effect of
accurately estimating the wheel tread roughness without
being affected by vibration of the railway vehicle even
during running.
30
Brief Description of Drawings
[0009] FIG. 1 is a block diagram illustrating a
configuration example of a wheel tread roughness estimation
5
device according to a first embodiment.
FIG. 2 is a diagram illustrating a configuration
example of a brake system of a railway vehicle equipped
with the wheel tread roughness estimation device and a
5 wheel tread roughening control device according to the
first embodiment.
FIG. 3 is a diagram illustrating an example of a set
value table stored in a database of the wheel tread
roughness estimation device according to the first
10 embodiment.
FIG. 4 is a flowchart illustrating an operation of the
wheel tread roughness estimation device according to the
first embodiment.
FIG. 5 is a diagram illustrating a configuration
15 example of processing circuitry implemented with a
processor and a memory as processing circuitry that
implements the wheel tread roughness estimation device
according to the first embodiment.
FIG. 6 is a diagram illustrating a configuration
20 example of processing circuitry configured as dedicated
hardware to serve as the processing circuitry that
implements the wheel tread roughness estimation device
according to the first embodiment.
FIG. 7 is a block diagram illustrating a configuration
25 example of a wheel tread roughness estimation device
according to a second embodiment.
FIG. 8 is a flowchart illustrating an operation of the
wheel tread roughness estimation device according to the
second embodiment.
30
Description of Embodiments
[0010] With reference to the drawings, a detailed
description is hereinafter provided of wheel tread
6
roughness estimation devices and wheel tread roughness
estimation methods according to embodiments of the present
disclosure.
[0011] First Embodiment.
5 FIG. 1 is a block diagram illustrating a configuration
example of a wheel tread roughness estimation device 30
according to a first embodiment. The wheel tread roughness
estimation device 30 includes a driving information
acquisition unit 31, a vehicle information acquisition unit
10 32, a tread roughening control information acquisition unit
33, a wheel tread roughness computation unit 34, and an
output unit 38. The wheel tread roughness computation unit
34 includes a database 35, a set value determination unit
36, and a tread roughness estimation unit 37. The wheel
15 tread roughness estimation device 30 is connected to a
wheel tread roughening control device 10, an environment
information acquisition unit 21, and a service route
information acquisition unit 22. As illustrated in FIG. 1,
the wheel tread roughening control device 10 and the wheel
20 tread roughness estimation device 30 constitute a wheel
tread roughness management system 40.
[0012] The driving information acquisition unit 31
obtains driving information of a railway vehicle from a
driver’s stand (or a driver’s seat) (not illustrated) that
25 is installed on the railway vehicle, a vehicle information
management device (not illustrated), or the like. The
driving information is, for example, information on braking
operation performed by a driver of the railway vehicle.
Examples of the information on the braking operation
30 include information indicating whether the railway vehicle
is power running or coasting, information indicating which
brake is used an air brake or a regenerative brake or a
ratio between the air brake and the regenerative brake,
7
information indicating which braking is used service
braking or emergency braking, and information on a current
notch, or the like. The driving information acquisition
unit 31 outputs the obtained driving information to the
5 wheel tread roughness computation unit 34.
[0013] The vehicle information acquisition unit 32
obtains vehicle information of the railway vehicle in
service. For example, the vehicle information acquisition
unit 32 obtains, from the vehicle information management
10 device or sensors installed on the railway vehicle,
information including air suspension (AS) pressure that is
variable load pressure representing a congestion degree of
the railway vehicle, BC pressure, and speed of the railway
vehicle, or the like as the vehicle information. The
15 vehicle information acquisition unit 32 outputs the
obtained vehicle information to the wheel tread roughness
computation unit 34.
[0014] The tread roughening control information
acquisition unit 33 obtains, from the wheel tread
20 roughening control device 10, tread roughening control
information that is information on wheel tread roughening
control in the wheel tread roughening control device 10.
The tread roughening control information is, for example,
information indicating a current ON-OFF status of the tread
25 roughening control in the wheel tread roughening control
device 10. The tread roughening control information
acquisition unit 33 outputs the obtained tread roughening
control information to the wheel tread roughness
computation unit 34.
30 [0015] The wheel tread roughness computation unit 34
determines a set value by selecting, on the basis of the
driving information obtained from the driving information
acquisition unit 31, the vehicle information obtained from
8
the vehicle information acquisition unit 32, and the tread
roughening control information obtained from the tread
roughening control information acquisition unit 33, the
corresponding set value from a set value table configured
5 according to the driving information, the vehicle
information, and the tread roughening control information.
The wheel tread roughness computation unit 34 computes an
up-to-date wheel tread roughness by adding the set value to
a preceding wheel tread roughness indicating a previously
10 computed roughness of a wheel tread. It is to be noted
that without using all of the driving information, the
vehicle information, and the tread roughening control
information, the wheel tread roughness computation unit 34
may select, from the set value table, the corresponding set
15 value based on at least one of the driving information, the
vehicle information, or the tread roughening control
information, when determining the set value.
[0016] The database 35 stores the set value table, which
is used by the wheel tread roughness computation unit 34.
20 The database 35 may store the driving information obtained
from the driving information acquisition unit 31, the
vehicle information obtained from the vehicle information
acquisition unit 32, the tread roughening control
information obtained from the tread roughening control
25 information acquisition unit 33, environment information
obtained from the environment information acquisition unit
21, and service route information obtained from the service
route information acquisition unit 22. An installation
location of the database 35 is not particularly limited.
30 The database 35 may be installed in a brake control unit
103 illustrated in FIG. 2 or another location or externally
to the railway vehicle 100.
[0017] A brief description is provided here of a brake
9
system of the railway vehicle, which is equipped with the
wheel tread roughness estimation device 30 and the wheel
tread roughening control device 10. FIG. 2 is a diagram
illustrating a configuration example of the brake system of
5 the railway vehicle 100, which is equipped with the wheel
tread roughness estimation device 30 and the wheel tread
roughening control device 10 according to the first
embodiment. A speed sensor 101 is installed on each of a
front and a rear truck of each railway vehicle 100, obtains
10 a speed signal 101D of each wheel 110, and outputs the
speed signal 101D to the brake control unit 103. A brake
command unit 102 outputs a brake command 102D for obtaining
a specified deceleration. The brake control unit 103
obtains the brake command 102D output from the brake
15 command unit 102, a variable load signal output from a
variable load device (not illustrated) that detects weight
of each railway vehicle 100, or the like, and outputs a
specified pressure control signal 103D. The pressure
control signal 103D is output from the brake control unit
20 103 through an electro-pneumatic conversion valve 104 to a
relay valve 105 and is used for production of a brake
cylinder pressure 105D. The electro-pneumatic conversion
valve 104 converts the pressure control signal 103D, which
is an electrical signal output from the brake control unit
25 103, into an air signal of a specified pressure. The relay
valve 105 amplifies the pressure control signal 103D that
has been converted into the air signal to a specified value
to improve responsiveness of the brake cylinder pressure
105D. The relay valve 105 is connected to a main air
30 reservoir 112. Since compressed air, which is air having a
specified pressure, is stored in the main air reservoir
112, the relay valve 105 is enabled to produce the
specified brake cylinder pressure 105D by outputting the
10
compressed air 112D corresponding to the pressure control
signal 103D.
[0018] A pressure sensor 106 detects the brake cylinder
pressure 105D and generates a feedback command 106D based
5 on the brake cylinder pressure 105D to return the feedback
command 106D to the brake control unit 103. A brake
cylinder 107 causes a brake shoe 108 to press against the
wheel 110 in accordance with intensity of the brake
cylinder pressure 105D. The brake shoe 108 is a friction
10 material having a specified friction coefficient. Braking
force of the railway vehicle 100 can be derived from
multiplication of the friction coefficient of the brake
shoe 108 by the brake cylinder pressure 105D. The brake
control unit 103 computes required braking force from
15 variable load information obtained from an air suspension
pressure sensor (not illustrated) and target deceleration
based on the brake command 102D and outputs a regenerative
pattern signal 113D to a regenerative brake control unit
114. The regenerative brake control unit 114, which is
20 installed in a main circuit control device (not
illustrated), outputs actual regenerative braking force
corresponding to actual torque as a regenerative feedback
signal 114D to the brake control unit 103. The brake
control unit 103 performs BC pressure control by
25 subtracting the value of the regenerative feedback signal
114D from the required braking force to obtain an air brake
supplement quantity and outputting the air brake supplement
quantity as the pressure control signal 103D to the
electro-pneumatic conversion valve 104.
30 [0019] When the air brake is frequently used, the wheel
tread of the railway vehicle 100 is roughened, thus
enabling desired braking force to be secured, with a mirror
surface condition of the wheel 110 also eliminated. On the
11
other hand, heavy use of the air brake on the railway
vehicle 100 does not allow for effective use of the
regenerative brake, resulting in no energy-saving effect.
Therefore, the wheel tread roughening control device 10
5 effectively uses the regenerative brake during normal
service braking, and when the wheel 110 is in the mirror
surface condition, the wheel tread roughening control
device 10 uses the air brake that causes the brake shoe
108, which is the friction material, to press against the
10 wheel 110 so as to roughen the tread of the wheel 110, thus
eliminating the mirror surface condition of the wheel 110.
The wheel tread roughness estimation device 30 estimates
and outputs, to the wheel tread roughening control device
10, the wheel tread roughness as wheel tread roughness
15 information.
[0020] A return is made to the description of FIG. 1.
The set value determination unit 36 determines the set
value by selecting, on the basis of the driving
information, the vehicle information, and the tread
20 roughening control information, the set value that
corresponds to the driving information, the vehicle
information, and the tread roughening control information
from the set value table, which is stored in the database
35. Without using all of the driving information, the
25 vehicle information, and the tread roughening control
information, the set value determination unit 36 may
select, from the set value table, the corresponding set
value based on the at least one of the driving information,
the vehicle information, or the tread roughening control
30 information, when determining the set value. The set value
determination unit 36 outputs the determined set value to
the tread roughness estimation unit 37.
[0021] The tread roughness estimation unit 37 computes
12
the up-to-date wheel tread roughness by adding the set
value determined by the set value determination unit 36 to
the preceding wheel tread roughness, thus estimating the
wheel tread roughness of the railway vehicle 100.
5 [0022] The output unit 38 outputs the up-to-date wheel
tread roughness computed by the wheel tread roughness
computation unit 34 as the wheel tread roughness
information to the wheel tread roughening control device
10. While the output unit 38 outputs the wheel tread
10 roughness information to the wheel tread roughening control
device 10 in the example of FIG. 1, the wheel tread
roughening control device 10 is not the limiting
destination for the output of the wheel tread roughness
information. For example, when the wheel tread roughness
15 information is used as information for maintenance or the
like, the output unit 38 may output the wheel tread
roughness information to a storage unit, such as a memory
(not illustrated), or transmit the wheel tread roughness
information to a server or the like that collects data for
20 the maintenance via a communication device (not
illustrated).
[0023] Using the wheel tread roughness information
estimated by the wheel tread roughness estimation device
30, the wheel tread roughening control device 10 performs
25 ON-OFF control of the tread roughening control.
[0024] The environment information acquisition unit 21
obtains the environment information including weather,
temperature, humidity, and others, around the railway
vehicle 100. This is because the weather, the temperature,
30 the humidity, and others affect effectiveness of the brake
on the railway vehicle 100. The environment information
acquisition unit 21 may be installed on the railway vehicle
100 or in a train operation management system disposed on
13
the ground, or the like. The environment information
acquisition unit 21 outputs the obtained environment
information to the wheel tread roughness estimation device
30.
5 [0025] The service route information acquisition unit 22
obtains the service route information, such as information
on a route on which the railway vehicle 100 runs. This is
because presence of any other railway vehicle 100, such as
a preceding railway vehicle 100 or a following railway
10 vehicle 100, is significant for application of the
regenerative brake on the railway vehicle 100, with
frequency of the presence of such other railway vehicle 100
differing, depending on whether the route on which the
railway vehicle 100 runs is suburban or urban. The service
15 route information acquisition unit 22 may be installed on
the railway vehicle 100 or in the train operation
management system disposed on the ground, or the like. The
service route information acquisition unit 22 outputs the
obtained service route information to the wheel tread
20 roughness estimation device 30.
[0026] A description is provided here of the set value
table stored in the database 35. FIG. 3 is a diagram
illustrating an example of the set value table stored in
the database 35 of the wheel tread roughness estimation
25 device 30 according to the first embodiment. As
illustrated in FIG. 3, the database 35 stores the abovementioned set value table where set values are entered for
each AS pressure and each speed. For example, when the AS
pressure is 350 kPa, with the speed of the railway vehicle
30 100 being 50 km/h, the set value determination unit 36
obtains -0.0002 mm as set value 1, +0.02 mm as set value 2,
+0.02 mm as set value 3, -0.002 mm as set value 4, and
+0.003 mm as set value 5. Regardless of the AS pressure
14
and the speed, set value 6 means “no change”. As
illustrated in FIG. 3, the wheel tread roughness
computation unit 34 is to have a negative value for the set
value when the wheel tread is in a situation of becoming a
5 mirror surface and a positive value for the set value when
the wheel tread is in a situation of becoming rough.
Values for each of those set values in the set value table
stored in the database 35 can be appropriately set or
changed, for example, by a person in charge at a railway
10 company that operates the railway vehicle 100 by means of
the wheel tread roughness estimation device 30 or another
device, such as a device external to the wheel tread
roughness estimation device 30. Examples of the device
external to the wheel tread roughness estimation device 30
15 include a vehicle information monitoring and analysis
system, a train control and management system, and a brake
control unit (BCU), or the like.
[0027] While the set value table illustrated in FIG. 3
is divided into three levels with respect to the AS
20 pressure and the speed by thresholds, the set value table
may be divided into two levels, or four or more levels.
While the set value table illustrated in FIG. 3 has the set
values entered for each AS pressure and each speed, set
values may be specified in the set value table solely for
25 the AS pressure or solely for the speed. The set value
table may be defined, using, for example, the BC pressure,
instead of the AS pressure.
[0028] The running of the railway vehicle 100 is
influenced by the environment information, namely the
30 weather, the temperature, the humidity, and others, and is
also influenced by the service route information, namely
the route on which the railway vehicle 100 runs, or the
like. Therefore, the database 35 may store a set value
15
table for each of conditions set for environment
information and a set value table for each of conditions
set for service route information. In that case, the set
value determination unit 36 determines set values by
5 selecting the set values from the set value tables that
match the environment information and the service route
information. As described above, the wheel tread roughness
computation unit 34 may obtain the environment information
including at least one of the weather, the temperature, or
10 the humidity, and determine the set value, using the
environment information. The wheel tread roughness
computation unit 34 may obtain the service route
information, which is the information on the route where
the railway vehicle 100 runs, and determine the set value,
15 using the service route information.
[0029] In a case of, for example, rainy weather or a
lower temperature, the wheel tread easily becomes a mirror
surface compared to when the weather is fine or when the
temperature is higher. In view of this matter, the set
20 value table prestored in the database 35 is configured with
set values that allow for the output of wheel tread
roughening information that causes the tread roughening
control to be easily ON to the wheel tread roughening
control device 10. The regenerative brake is assumed to be
25 more frequent on urban routes than on suburban routes. In
view of this matter, the set value table prestored in the
database 35 is configured with set values that allow for
the output of wheel tread roughening information that
causes the tread roughening control to be easily ON to the
30 wheel tread roughening control device 10. For a train made
up of a plurality of the railway vehicles 100, the wheel
tread roughness computation unit 34 may have the database
35 store a set value table corresponding to the number of
16
railway vehicles 100 making up the train and may change the
set value table to be used in accordance with the number of
railway vehicles 100.
[0030] A description is provided of how the wheel tread
5 roughness estimation device 30 operates. FIG. 4 is a
flowchart illustrating an operation of the wheel tread
roughness estimation device 30 according to the first
embodiment. The wheel tread roughness estimation device 30
obtains the various types of information (step S31).
10 Specifically, in the wheel tread roughness estimation
device 30, the driving information acquisition unit 31
obtains the driving information, the vehicle information
acquisition unit 32 obtains the vehicle information, and
the tread roughening control information acquisition unit
15 33 obtains the tread roughening control information.
[0031] In the wheel tread roughness computation unit 34,
the set value determination unit 36 determines whether or
not the railway vehicle 100 is stopping (step S32). The
set value determination unit 36 can determine whether or
20 not the railway vehicle 100 is stopping on the basis of the
speed of the railway vehicle 100 that is included in the
vehicle information. In cases where position information
of the railway vehicle 100 is obtained, the set value
determination unit 36 may use the position information of
25 the railway vehicle 100 to determine whether or not the
railway vehicle 100 is stopping. If the railway vehicle
100 is stopping (step S32: Yes), the set value
determination unit 36 determines that the set value be 0 to
maintain the current status (step S33).
30 [0032] If the railway vehicle 100 is running (step S32:
No), the set value determination unit 36 determines whether
the railway vehicle 100 is in a state of power running or
coasting or not (step S34). The set value determination
17
unit 36 can determine whether or not the railway vehicle
100 is in the state of power running or coasting on the
basis of the driving information. If the railway vehicle
100 is in the state of power running or coasting (step S34:
5 Yes), the set value determination unit 36 selects a
corresponding set value from the set value table stored in
the database 35 to determine that the set value be set
value 1 (step S35).
[0033] If the railway vehicle 100 is not in the state of
10 power running or coasting (step S34: No), the set value
determination unit 36 determines whether the railway
vehicle 100 is in a state of service braking with the
regenerative brake OFF or not (step S36). The set value
determination unit 36 can determine whether or not the
15 railway vehicle 100 is in the state of service braking with
the regenerative brake OFF on the basis of the driving
information. If the railway vehicle 100 is in the state of
service braking with the regenerative brake OFF (step S36:
Yes), the set value determination unit 36 selects a
20 corresponding set value from the set value table stored in
the database 35 to determine that the set value be set
value 2 (step S37).
[0034] If the railway vehicle 100 is not in the state of
service braking with the regenerative brake OFF (step S36:
25 No), the set value determination unit 36 determines whether
emergency braking is in progress or not (step S38). The
set value determination unit 36 can determine whether or
not the railway vehicle 100 is in the state of emergency
braking on the basis of the driving information. If the
30 emergency braking is in progress (step S38: Yes), the set
value determination unit 36 selects a corresponding set
value from the set value table stored in the database 35 to
determine that the set value be set value 3 (step S39).
18
[0035] If the emergency braking is not in progress (step
S38: No), the set value determination unit 36 determines
whether or not the service braking is in progress with the
tread roughening control OFF (step S40). The set value
5 determination unit 36 can determine whether or not the
railway vehicle 100 is in the state of service braking with
the tread roughening control OFF on the basis of the
driving information and the tread roughening control
information. If the service braking is in progress with
10 the tread roughening control OFF (step S40: Yes), the set
value determination unit 36 selects a corresponding set
value from the set value table stored in the database 35 to
determine that the set value be set value 4 (step S41).
[0036] If the state of service braking with the tread
15 roughening control OFF is not the case (step S40: No), the
set value determination unit 36 determines whether or not
the service braking is in progress with the tread
roughening control ON (step S42). The set value
determination unit 36 can determine whether or not the
20 railway vehicle 100 is in the state of service braking with
the tread roughening control ON on the basis of the driving
information and the tread roughening control information.
If the service braking is in progress with the tread
roughening control ON (step S42: Yes), the set value
25 determination unit 36 selects a corresponding set value
from the set value table stored in the database 35 to
determine that the set value be set value 5 (step S43). If
the service braking is not in progress with the tread
roughening control ON (step S42: No), the set value
30 determination unit 36 determines that the set value be 0 to
maintain the current status (the status quo) (step S44).
[0037] The set value determination unit 36 outputs the
set value determined at step S33, S35, S37, S39, S41, S43,
19
or S44 to the tread roughness estimation unit 37. The
tread roughness estimation unit 37 computes an up-to-date
wheel tread roughness by adding the set value to the
previously computed wheel tread roughness which is the
5 current value (step S45). For initial computation after
the railway vehicle 100 begins operating, the tread
roughness estimation unit 37 of the wheel tread roughness
computation unit 34 uses, as the preceding wheel tread
roughness, the up-to-date wheel tread roughness last
10 computed in a preceding operation or a wheel tread
roughness measured in an inspection. The up-to-date wheel
tread roughness last computed in the preceding operation or
the wheel tread roughness measured in the inspection may be
retained by the set value determination unit 36 or retained
15 by the BCU of the railway vehicle 100, or the like. The
tread roughness estimation unit 37 outputs the computed upto-date wheel tread roughness to the output unit 38. The
output unit 38 outputs the up-to-date wheel tread roughness
obtained from the tread roughness estimation unit 37 as the
20 wheel tread roughness information (step S46).
[0038] A description is provided next of a hardware
configuration of the wheel tread roughness estimation
device 30 according to the first embodiment. The driving
information acquisition unit 31, the vehicle information
25 acquisition unit 32, the tread roughening control
information acquisition unit 33, the wheel tread roughness
computation unit 34, and the output unit 38 of the wheel
tread roughness estimation device 30 are implemented with
processing circuitry. The processing circuitry may include
30 a memory that stores programs and a processor that executes
the programs stored in the memory or may be dedicated
hardware. The processing circuitry is also referred to as
control circuitry.
20
[0039] FIG. 5 is a diagram illustrating a configuration
example of processing circuitry 90 implemented with a
processor 91 and a memory 92 as the processing circuitry
that implements the wheel tread roughness estimation device
5 30 according to the first embodiment. The processing
circuitry 90 illustrated in FIG. 5 is control circuitry and
includes the processor 91 and the memory 92. For the
processing circuitry 90 that includes the processor 91 and
the memory 92, the functions of the processing circuitry 90
10 are implemented with software, firmware, or a combination
of software and firmware. The software or the firmware is
described as programs and is stored in the memory 92. In
the processing circuitry 90, the processor 91 reads and
executes the programs stored in the memory 92 to implement
15 the functions. This means that the memory 92 is included
in the processing circuitry 90 to store the programs that
result in the execution of the operations of the wheel
tread roughness estimation device 30. These programs can
be said to be programs that cause the functions that the
20 processing circuitry 90 implements to be performed by the
wheel tread roughness estimation device 30. These programs
may be stored in a storage medium and provided or may be
provided by another means such as a communication medium.
[0040] The above programs can also be said to cause the
25 wheel tread roughness estimation device 30 to perform a
first step of obtaining, with the driving information
acquisition unit 31, the driving information of the railway
vehicle 100; a second step of obtaining, with the vehicle
information acquisition unit 32, the vehicle information of
30 the railway vehicle 100 in service; a third step of
determining, with the wheel tread roughness computation
unit 34, the set value on the basis of the driving
information and the vehicle information and computing, with
21
the wheel tread roughness computation unit 34, the up-todate wheel tread roughness by adding the set value to the
preceding wheel tread roughness, which indicates the
computed roughness of the wheel tread; and a fourth step of
5 outputting, with the output unit 38, the up-to-date wheel
tread roughness computed in the third step as the wheel
tread roughness information.
[0041] Here examples of the processor 91 include a
central processing unit (CPU), a processing unit, an
10 arithmetic unit, a microprocessor, a microcomputer, and a
digital signal processor (DSP), or the like. Examples that
each correspond to the memory 92 include nonvolatile and
volatile semiconductor memories, such as a random-access
memory (RAM), a read-only memory (ROM), a flash memory, an
15 erasable programmable ROM (EPROM), and an electrically
EPROM (EEPROM) (registered trademark), a magnetic disk, a
flexible disk, an optical disk, a compact disk, a mini
disk, and a digital versatile disc (DVD), or the like.
[0042] FIG. 6 is a diagram illustrating a configuration
20 example of processing circuitry 93 configured as dedicated
hardware to serve as the processing circuitry that
implements the wheel tread roughness estimation device 30
according to the first embodiment. Examples that each
correspond to the processing circuitry 93 illustrated in
25 FIG. 6 include a single circuit, a composite circuit, a
programmed processor, a parallel programmed processor, an
application-specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), and combinations of these.
The processing circuitry 93 may be realized partly by
30 dedicated hardware and partly by software or firmware. By
including the dedicated hardware, the software, the
firmware or a combination of these, the processing
circuitry 93 is capable of implementing the above
22
functions.
[0043] As described above, the wheel tread roughness
estimation device 30 according to the present embodiment
determines the set value by selecting, using the driving
5 information, the vehicle information, and the tread
roughening control information, the set value from the set
value table, computes the up-to-date wheel tread roughness
by adding the set value to the preceding wheel tread
roughness, and outputs the up-to-date wheel tread roughness
10 as the wheel tread roughness information to the wheel tread
roughening control device 10. Therefore, the wheel tread
roughness estimation device 30 is capable of accurate
estimation of the wheel tread roughness without being
affected by vibration of the railway vehicle 100 even
15 during running.
[0044] Second Embodiment.
In the first embodiment, the wheel tread roughness
estimation device 30 determines the set value by selecting
the set value from the set value table prestored in the
20 database 35. In a second embodiment, a description is
provided of a case of a wheel tread roughness estimation
device that determines a set value by computation.
[0045] FIG. 7 is a block diagram illustrating a
configuration example of the wheel tread roughness
25 estimation device 30a according to the second embodiment.
The wheel tread roughness estimation device 30a includes
the driving information acquisition unit 31, the vehicle
information acquisition unit 32, a wheel tread roughness
computation unit 34a, and the output unit 38. The wheel
30 tread roughness computation unit 34a includes a set value
determination unit 36a and a tread roughness estimation
unit 37a. The wheel tread roughness estimation device 30a
is connected to the wheel tread roughening control device
23
10. As illustrated in FIG. 7, the wheel tread roughening
control device 10 and the wheel tread roughness estimation
device 30a constitute a wheel tread roughness management
system 40a.
5 [0046] The wheel tread roughness computation unit 34a
determines a set value by computing the set value based on
the driving information obtained from the driving
information acquisition unit 31 and the vehicle information
obtained from the vehicle information acquisition unit 32.
10 The wheel tread roughness computation unit 34a computes an
up-to-date wheel tread roughness by adding the set value to
a preceding wheel tread roughness indicating a previously
computed roughness of a wheel tread. Without using all of
the driving information and the vehicle information, the
15 wheel tread roughness computation unit 34a may compute a
set value based on at least one of the driving information
and the vehicle information when determining the set value.
[0047] The set value determination unit 36a determines
the set value by computing the set value based on the
20 driving information and the vehicle information. Without
using all of the driving information and the vehicle
information, the set value determination unit 36a may
compute the set value based on the at least one of the
driving information and the vehicle information when
25 determining the set value. The set value determination
unit 36a outputs the determined set value to the tread
roughness estimation unit 37a.
[0048] The tread roughness estimation unit 37a computes
the up-to-date wheel tread roughness by adding the set
30 value determined by the set value determination unit 36a to
the preceding wheel tread roughness, thus estimating the
wheel tread roughness of the railway vehicle 100.
[0049] A description is provided of how the wheel tread
24
roughness estimation device 30a operates. FIG. 8 is a
flowchart illustrating an operation of the wheel tread
roughness estimation device 30a according to the second
embodiment. The wheel tread roughness estimation device
5 30a obtains the various types of information (step S51).
Specifically, in the wheel tread roughness estimation
device 30a, the driving information acquisition unit 31
obtains the driving information, and the vehicle
information acquisition unit 32 obtains the vehicle
10 information.
[0050] The set value determination unit 36a of the wheel
tread roughness computation unit 34a determines whether or
not the railway vehicle 100 is stopping (step S52). The
set value determination unit 36a can determine whether or
15 not the railway vehicle 100 is stopping on the basis of the
speed of the railway vehicle 100 that is included in the
vehicle information. In cases where position information
of the railway vehicle 100 is obtained, the set value
determination unit 36a may use the position information of
20 the railway vehicle 100 to determine whether or not the
railway vehicle 100 is stopping. If the railway vehicle
100 is stopping (step S52: Yes), the set value
determination unit 36a determines a set value by computing
the set value (step S53). In this case, the set value
25 determination unit 36a computes the set value according to
Formula (1).
[0051] Set value=Coefficient α×BC pressure×Duration of
BC pressure×Speed (1)
[0052] Formula (1) expresses a cumulative value of
30 pressure applied when the friction material is pressed
against the wheel tread of the railway vehicle 100. At
step S53, since the speed is 0, the set value becomes 0
regardless of a value of the coefficient α. Therefore, the
25
set value determination unit 36a determines that the set
value be 0.
[0053] If the railway vehicle 100 is running (step S52:
No), the set value determination unit 36a determines
5 whether a regenerative brake is ON with the BC pressure in
a precharge state or not (step S54). The set value
determination unit 36a can determine whether or not the
regenerative brake is ON with the BC pressure in the
precharge state for the railway vehicle 100 on the basis of
10 the driving information. If the regenerative brake is ON
with the BC pressure in the precharge state (step S54:
Yes), the set value determination unit 36a determines a set
value by computing the set value (step S55). At this time,
the set value determination unit 36a sets the coefficient α
15 in Formula (1) to a negative value. This means that the
set value computed at step S55 becomes a negative value.
If “the regenerative brake is ON with the BC pressure in
the precharge state” is not the case (step S54: No), the
set value determination unit 36a determines a set value by
20 computing the set value (step S56). At this time, the set
value determination unit 36a sets the coefficient α in
Formula (1) to a positive value. This means that the set
value computed at step S56 becomes a positive value.
[0054] The set value determination unit 36a outputs the
25 set value determined at step S53, S55, or S56 to the tread
roughness estimation unit 37a. The tread roughness
estimation unit 37a computes an up-to-date wheel tread
roughness by adding the set value to the previously
computed wheel tread roughness, namely the current value
30 (step S57). As described above, the set value
determination unit 36a of the wheel tread roughness
computation unit 34a determines the set value by computing
the set value through the use of the specific arithmetic
26
expression that uses the driving information and the
vehicle information. For initial computation after the
railway vehicle 100 begins operating, the tread roughness
estimation unit 37a of the wheel tread roughness
5 computation unit 34a uses the up-to-date wheel tread
roughness last computed in a preceding operation or a wheel
tread roughness measured in an inspection as the preceding
wheel tread roughness. The tread roughness estimation unit
37a outputs the computed up-to-date wheel tread roughness
10 to the output unit 38. The output unit 38 outputs the upto-date wheel tread roughness obtained from the tread
roughness estimation unit 37a as wheel tread roughness
information (step S58).
[0055] In the example of FIG. 8, the set value
15 determination unit 36a computes the set value when a brake
signal is present in the railway vehicle 100; however, this
is not limiting. Even when the brake signal is not present
in the railway vehicle 100, the set value determination
unit 36a may compute a set value, using, for example,
20 values obtained during power running or coasting.
[0056] A description is provided next of a hardware
configuration of the wheel tread roughness estimation
device 30a according to the second embodiment. The driving
information acquisition unit 31, the vehicle information
25 acquisition unit 32, the wheel tread roughness computation
unit 34a, and the output unit 38 of the wheel tread
roughness estimation device 30a are implemented with
processing circuitry. The processing circuitry may include
a memory that stores programs and a processor that executes
30 the programs stored in the memory or may be dedicated
hardware.
[0057] As described above, the wheel tread roughness
estimation device 30a according to the present embodiment
27
determines the set value by computing the set value, using
the driving information and the vehicle information,
computes the up-to-date wheel tread roughness by adding the
set value to the preceding wheel tread roughness, and
5 outputs the up-to-date wheel tread roughness as the wheel
tread roughness information to the wheel tread roughening
control device 10. Therefore, the wheel tread roughness
estimation device 30a is capable of accurate estimation of
the wheel tread roughness without being affected by
10 vibration of the railway vehicle 100 even during running.
[0058] The above configurations illustrated in the
embodiments are illustrative, can be combined with other
techniques that are publicly known, and can be partly
omitted or changed without departing from the gist. The
15 embodiments can be combined with each other.
Reference Signs List
[0059] 10 wheel tread roughening control device; 21
environment information acquisition unit; 22 service route
20 information acquisition unit; 30, 30a wheel tread
roughness estimation device; 31 driving information
acquisition unit; 32 vehicle information acquisition unit;
33 tread roughening control information acquisition unit;
34, 34a wheel tread roughness computation unit; 35
25 database; 36, 36a set value determination unit; 37, 37a
tread roughness estimation unit; 38 output unit; 40, 40a
wheel tread roughness management system; 100 railway
vehicle; 101 speed sensor; 102 brake command unit; 103
brake control unit; 104 electro-pneumatic conversion
30 valve; 105 relay valve; 106 pressure sensor; 107 brake
cylinder; 108 brake shoe; 110 wheel; 112 main air
reservoir; 114 regenerative brake control unit.

We Claim :
[Claim 1] A wheel tread roughness estimation device
comprising:
a driving information acquisition unit to obtain
5 driving information of a railway vehicle;
a vehicle information acquisition unit to obtain
vehicle information of the railway vehicle in service;
a wheel tread roughness computation unit to determine
a set value on a basis of the driving information and the
10 vehicle information and compute an up-to-date wheel tread
roughness by adding the set value to a preceding wheel
tread roughness indicating a previously computed roughness
of a wheel tread; and
an output unit to output the up-to-date wheel tread
15 roughness computed by the wheel tread roughness computation
unit as wheel tread roughness information.
[Claim 2] The wheel tread roughness estimation device
according to claim 1, comprising
20 a tread roughening control information acquisition
unit to obtain tread roughening control information from a
wheel tread roughening control device connected to the
wheel tread roughness estimation device, the tread
roughening control information being information on wheel
25 tread roughening control in the wheel tread roughening
control device, wherein
the wheel tread roughness computation unit selects, on
a basis of the driving information, the vehicle
information, and the tread roughening control information,
30 the corresponding set value from a set value table
configured according to the driving information, the
vehicle information, and the tread roughening control
information, and determines the selected set value as the
29
set value.
[Claim 3] The wheel tread roughness estimation device
according to claim 1 or 2, wherein
5 the wheel tread roughness computation unit obtains
environment information including at least one of weather,
temperature, or humidity and determines the set value,
using the environment information.
10 [Claim 4] The wheel tread roughness estimation device
according to any one of claims 1 to 3, wherein
the wheel tread roughness computation unit obtains
service route information and determines the set value,
using the service route information, the service route
15 information being information on a route where the railway
vehicle runs.
[Claim 5] The wheel tread roughness estimation device
according to claim 1, wherein
20 the wheel tread roughness computation unit computes
the set value through use of a specific arithmetic
expression that uses the driving information and the
vehicle information, and determines the computed set value
as the set value.
25
[Claim 6] The wheel tread roughness estimation device
according to any one of claims 1 to 5, wherein
the wheel tread roughness computation unit is to have
a negative value for the set value when the wheel tread is
30 in a situation of becoming a mirror surface and a positive
value for the set value when the wheel tread is in a
situation of becoming rough.
30
[Claim 7] The wheel tread roughness estimation device
according to any one of claims 1 to 6, wherein
for initial computation after an operation begins, the
wheel tread roughness computation unit uses, as the
5 preceding wheel tread roughness, the up-to-date wheel tread
roughness last computed in a preceding operation or a wheel
tread roughness measured in an inspection.
[Claim 8] A wheel tread roughness estimation method to be
10 performed by a wheel tread roughness estimation device, the
wheel tread roughness estimation method comprising:
a first step of obtaining, by a driving information
acquisition unit, driving information of a railway vehicle;
a second step of obtaining, by a vehicle information
15 acquisition unit, vehicle information of the railway
vehicle in service;
a third step of determining, by a wheel tread
roughness computation unit, a set value on a basis of the
driving information and the vehicle information and
20 computing, by the wheel tread roughness computation unit,
an up-to-date wheel tread roughness by adding the set value
to a preceding wheel tread roughness indicating a
previously computed roughness of a wheel tread; and
a fourth step of outputting, by an output unit, the
25 up-to-date wheel tread roughness computed in the third step
as wheel tread roughness information.
[Claim 9] The wheel tread roughness estimation method
according to claim 8, comprising
30 a fifth step of obtaining, by a tread roughening
control information acquisition unit, tread roughening
control information from a wheel tread roughening control
device connected to the wheel tread roughness estimation
31
device, the tread roughening control information being
information on wheel tread roughening control in the wheel
tread roughening control device, wherein
when determining the set value in the third step, the
5 wheel tread roughness computation unit selects, on a basis
of the driving information, the vehicle information, and
the tread roughening control information, the corresponding
set value from a set value table configured according to
the driving information, the vehicle information, and the
10 tread roughening control information, and determines the
selected set value as the set value.
[Claim 10] The wheel tread roughness estimation method
according to claim 8 or 9, wherein
15 in the third step, the wheel tread roughness
computation unit obtains environment information including
at least one of weather, temperature, or humidity, and
determines the set value using the environment information.
20 [Claim 11] The wheel tread roughness estimation method
according to any one of claims 8 to 10, wherein
in the third step, the wheel tread roughness
computation unit obtains service route information, and
determines the set value using the service route
25 information, the service route information being
information on a route where the railway vehicle runs.
[Claim 12] The wheel tread roughness estimation method
according to claim 8, wherein
30 in the third step, the wheel tread roughness
computation unit computes the set value through use of a
specific arithmetic expression that uses the driving
information and the vehicle information, and determines the
32
computed set value as the set value.
[Claim 13] The wheel tread roughness estimation method
according to any one of claims 8 to 12, wherein
5 in the third step, the wheel tread roughness
computation unit is to have a negative value for the set
value when the wheel tread is in a situation of becoming a
mirror surface and a positive value for the set value when
the wheel tread is in a situation of becoming rough.
10
[Claim 14] The wheel tread roughness estimation method
according to any one of claims 8 to 13, wherein
in the third step, for initial computation after an
operation begins, the wheel tread roughness computation
15 unit uses, as the preceding wheel tread roughness, the upto-date wheel tread roughness last computed in a preceding
operation or a wheel tread roughness measured in an
inspection.