FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
IN-VEHICLE EQUIPMENT AND DETERIORATION DETERMINING METHOD
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
Technical Field
[0001] The present disclosure relates to an in-vehicle device and a method of
determining degradation.
5 Background Art
[0002] Housings of in-vehicle devices installed in vehicles accommodate electronic
equipment including power converters, circuit breakers, and transformers, for example.
These housings are provided with openings that allow for inspection and maintenance of
the internal electronic equipment. The openings are covered with covers that can be
10 opened and closed so as to inhibit contaminants, such as dust and water drops, from
entering the housings. A typical example of these types of in-vehicle devices is
disclosed in Patent Literature 1.
Citation List
Patent Literature
15 [0003] Patent Literature 1: Unexamined Japanese Patent Application Publication
No. 2014-8802
Summary of Invention
Technical Problem
[0004] The control device for a railway vehicle disclosed in Patent Literature 1,
20 which is an example of the in-vehicle device, includes a housing that accommodates an
inverter unit and a control unit, for example. The housing has an opening for
maintenance covered with an attachable and detachable cover. The opening may be
provided with a sealing member there around in order to improve the dust resistance and
waterproofness of the in-vehicle device. The sealing member is held between the cover
25 and the housing while the cover is closed, and thereby inhibits contaminants, such as dust
and water drops, from entering the housing through the opening. Unfortunately, when
the resilience of the sealing member decreases due to degradation of the sealing member,
3
for example, a gap is formed between the sealing member and the cover or the housing
while the cover is closed, thereby impairing the waterproofness and dust resistance of the
in-vehicle device.
[0005] An objective of the present disclosure, which has been accomplished in
5 view of the above situations, is to provide an in-vehicle device and a method of
determining degradation that can determine whether any degradation occurs in a sealing
member.
Solution to Problem
[0006] In order to achieve the above objective, an in-vehicle device according to an
10 aspect of the present disclosure is installed in a vehicle, and includes a housing, a cover, a
sealing member, at least one first vibration sensor, and a degradation determiner. The
housing has an opening. The cover is disposed over the opening and is openable and
closable. The sealing member is disposed around the opening such that the sealing
member is held between the housing and the cover when the cover is closed. The at
15 least one first vibration sensor measures mechanical vibration of the cover. The
degradation determiner determines, based on the mechanical vibration measured by the at
least one first vibration sensor while the cover is closed, whether any degradation occurs
in the sealing member.
Advantageous Effects of Invention
20 [0007] The in-vehicle device according to an aspect of the present disclosure can
determine whether any degradation occurs in the sealing member, on the basis of the
mechanical vibration of the cover measured by the at least one first vibration sensor.
Brief Description of Drawings
[0008] FIG. 1 is a perspective view of an in-vehicle device according to
25 Embodiment 1;
FIG. 2 is another perspective view of the in-vehicle device according to
Embodiment 1;
4
FIG. 3 is a partial sectional view of the in-vehicle device according to Embodiment
1 taken along the line A-A of FIG. 1;
FIG. 4 is a perspective view of a cover according to Embodiment 1;
FIG. 5 is a block diagram illustrating a degradation determiner according to
5 Embodiment 1;
FIG. 6 illustrates an exemplary hardware configuration of the degradation
determiner according to Embodiment 1;
FIG. 7 is a flowchart illustrating exemplary steps of a degradation determining
process executed by the degradation determiner according to Embodiment 1;
10 FIG. 8 is a perspective view of an in-vehicle device according to Embodiment 2;
FIG. 9 is another perspective view of the in-vehicle device according to
Embodiment 2;
FIG. 10 is a perspective view of a cover according to Embodiment 2;
FIG. 11 is a block diagram illustrating a degradation determiner according to
15 Embodiment 2;
FIG. 12 is a flowchart illustrating exemplary steps of a degradation determining
process executed by the degradation determiner according to Embodiment 2;
FIG. 13 is a perspective view of an in-vehicle device according to Embodiment 3;
FIG. 14 is a partial sectional view of the in-vehicle device according to
20 Embodiment 3 taken along the line B-B of FIG. 13;
FIG. 15 is a block diagram illustrating a degradation determiner according to
Embodiment 3;
FIG. 16 is a flowchart illustrating exemplary steps of a degradation determining
process executed by the degradation determiner according to Embodiment 3;
25 FIG. 17 is a perspective view of an in-vehicle device according to Embodiment 4;
FIG. 18 is another perspective view of the in-vehicle device according to
Embodiment 4;
5
FIG. 19 is a block diagram illustrating a degradation determiner according to
Embodiment 4; and
FIG. 20 is a flowchart illustrating exemplary steps of a degradation determining
process executed by the degradation determiner according to Embodiment 4.
5 Description of Embodiments
[0009] An in-vehicle device and a method of determining degradation according to
embodiments of the present disclosure are described in detail below with reference to the
accompanying drawings. In the drawings, the components identical or corresponding to
each other are provided with the same reference symbol.
10 [0010] Embodiment 1
A typical example of an in-vehicle device installed in a vehicle is a control device
for a railway vehicle including a power converter, a circuit breaker, and a transformer, for
example. An in-vehicle device 1 according to Embodiment 1 is described below
focusing on an exemplary control device installed under the floor of a railway vehicle.
15 As illustrated in FIG. 1, the in-vehicle device 1 includes a housing 10 to be fixed under
the floor of the railway vehicle with fitting members, which are not illustrated, an
openable and closable cover 11, and two support members 12 to support the cover 11.
[0011] The in-vehicle device 1 also includes a first vibration sensor 13 to measure
mechanical vibration of the cover 11. As illustrated in FIG. 2, which is a perspective
20 view of the in-vehicle device 1 after removal of the cover 11, the housing 10 is provided
with an opening 10a. As illustrated in FIG. 2, the in-vehicle device 1 further includes a
sealing member 14 disposed around the opening 10a such that the sealing member 14 is
held between the housing 10 and the cover 11 when the cover 11 is closed.
[0012] In FIGS. 1 and 2, the Z axis indicates the vertical direction, the Y axis
25 indicates the direction in which the opening 10a extends through the housing 10, and the
X axis extends in the horizontal direction along the surface of the housing 10 provided
with the opening 10a. The X, Y, and Z axes are orthogonal to each other.
6
[0013] In the case where no degradation with age occurs in the sealing member 14,
the sealing member 14 held and pressed between the housing 10 and the cover 11 while
the cover 11 is closed has a sufficiently high resilience. As illustrated in FIG. 3, which
is a partial sectional view taken along the line A-A of FIG. 1, this configuration can
5 prevent a gap from being formed between the cover 11 and the housing 10. The
structure with no gap can inhibit contaminants, such as dust and water drops, from
entering the housing 10 through the opening 10a. FIG. 3 does not illustrate electronic
equipment 71.
[0014] Unfortunately, when the resilience of the sealing member 14 decreases due
10 to degradation with age, for example, a gap is formed between the sealing member 14
and the cover 11 or the housing 10 while the cover 11 is closed. This gap may allow
contaminants, such as dust and water drops, to enter the housing 10 through the opening
10a.
[0015] When a gap is formed between the sealing member 14 and the cover 11 or
15 the housing 10, the mechanical vibration of the cover 11 during running of the vehicle
becomes bigger than that in the case of no gap between the sealing member 14 and the
cover 11 or the housing 10. In view of these facts, the in-vehicle device 1 further
includes a degradation determiner 31, which is described below, to determine whether
any degradation occurs in the sealing member 14 on the basis of the mechanical vibration
20 measured by the first vibration sensor 13 while the cover 11 is closed. The in-vehicle
device 1 can therefore determine whether any degradation occurs in the sealing member
14.
[0016] The individual components of the in-vehicle device 1 are described in detail
below.
25 As illustrated in FIG. 2, the housing 10 accommodates the electronic equipment 71
including a power converter, a circuit breaker, and a transformer, for example. The
housing has the opening 10a on a side surface of the housing 10. This opening 10a
7
allows for maintenance of the electronic equipment 71 accommodated in the housing 10.
[0017] As illustrated in FIGS. 1 and 2, the cover 11 is disposed over the opening
10a and the circumference of the opening 10a. The cover 11 has an outer surface 11a
that faces the outside of the housing 10, and the outer surface 11a is provided with two
5 engaging members 11b fixed with fastening members. Each of the engaging members
11b has a through hole. The engaging members 11b engage with the respective support
members 12 while the support members 12 are inserted in the respective through holes of
the engaging members 11b. The engaging members 11b are rotatable about a rotational
axis AX1 while the support members 12 are inserted in the respective through holes.
10 The cover 11 is thus supported by the two support members 12 so as to be rotatable about
the rotational axis AX1, and openable and closable by rotating about the rotational axis
AX1. In FIG. 1, the rotational axis AX1 is represented by the dashed and single-dotted
line. The rotational axis AX1 extends in the X-axis direction, that is, the horizontal
direction.
15 [0018] The cover 11 has an inner surface 11c that faces the inside of the housing 10,
and the inner surface 11c is provided with the first vibration sensor 13, as illustrated in
FIG. 4. FIG. 4 illustrates the cover 11 as viewed from the inside of the housing 10 while
the cover 11 is closed.
[0019] As illustrated in FIGS. 1 and 2, the two support members 12 are fixed with
20 fastening members on the surface of the housing 10 provided with the opening 10a.
Specifically, the two support members 12 are arranged in the X-axis direction at positions
above the opening 10a in the vertical direction. Each of the support members 12 has
protrusions extending in a direction away from the housing 10, and each of the
protrusions has a notch. The protrusions of the support member 12 are inserted in each
25 of the through holes of the engaging members 11b and the engaging member 11b
engages with the notches of the support member 12, so that the two support members 12
support the cover 11 such that the cover 11 is rotatable about the rotational axis AX1.
8
[0020] The first vibration sensor 13 is mounted on the cover 11 and measures
mechanical vibration of the cover 11. A typical example of the first vibration sensor 13
is a contact acceleration sensor.
[0021] The vibration of the cover 11 generated during running of the vehicle varies
5 depending on the position in the cover 11. Specifically, the vibration of the cover 11 is
bigger at a position more distant from the engaging members 11b supported by the
support members 12. The first vibration sensor 13 is thus preferably disposed at a
position at least a first distance away from each of the support members 12 while the
cover 11 is closed. The first distance is defined in view of the parameters, such as the
10 size of the cover 11 and the positions of the support members 12. For example, the first
distance is defined to be equal to the half of the length of the cover 11 in the transverse
direction.
[0022] More preferably, the first vibration sensor 13 is mounted on the inner
surface 11c of the cover 11 at the position so as to maximize the distance from the
15 support members 12 while the cover 11 is closed, among the mountable positions in the
inner surface 11c of the cover 11. In the example illustrated in FIG. 4, the first vibration
sensor 13 is mounted on the inner surface 11c of the cover 11 at the position in the center
in the X-axis direction in the vertically bottom portion.
[0023] The first vibration sensor 13 is connected to a cable 15. The first vibration
20 sensor 13 is fed with electric power and transmits measured values to the degradation
determiner 31 via the cable 15. The first vibration sensor 13 is preferably fed with
electric power from the electronic equipment 71.
[0024] The sealing member 14 has a groove 14a to engage with an edge 10b of the
opening 10a, as illustrated in FIG. 3. The engagement of the groove 14a of the sealing
25 member 14 with the edge 10b of the opening 10a allows the sealing member 14 to be
attached to the housing 10 while being disposed around the opening 10a. When the
cover 11 is closed, the sealing member 14 is held between the housing 10 and the cover
9
11. The sealing member 14 is made of a material resilient to pressure, such as synthetic
rubber or resin, for example.
[0025] The degradation determiner 31 is accommodated in the housing 10, and
determines whether any degradation occurs in the sealing member 14 on the basis of the
5 oscillation frequency of the mechanical vibration of the cover 11. In detail, as illustrated
in FIG. 5, the degradation determiner 31 includes a sampling circuit 41 to sample values
measured by the first vibration sensor 13, an FFT circuit 42 to generate a piece of
frequency-domain data from the sampled values measured by the first vibration sensor 13,
a determination circuit 43 to calculate an oscillation frequency from the piece of
10 frequency-domain data and determine whether the calculated oscillation frequency falls
within a predetermined frequency range, a communication circuit 44 to transmit a result
of determination performed by the determination circuit 43 to a train information
management system 91, and a control circuit 45 to control the individual components of
the degradation determiner 31.
15 [0026] The individual components of the degradation determiner 31 are described
in detail below.
The sampling circuit 41 samples a value measured by the first vibration sensor 13
every predetermined sampling period, and outputs the sampled values measured by the
first vibration sensor 13 to the FFT circuit 42.
20 [0027] The FFT circuit 42 executes fast Fourier transform (FFT) on the values
measured by the first vibration sensor 13 and sampled by the sampling circuit 41 and
thereby generates a piece of frequency-domain data. The FFT circuit 42 then outputs
the piece of frequency-domain data to the determination circuit 43.
[0028] The determination circuit 43 calculates an oscillation frequency from the
25 peak value of the piece of frequency-domain data. The determination circuit 43 then
determines whether the calculated oscillation frequency falls within a predetermined
frequency range. For example, the determination circuit 43 includes a peak detecting
10
circuit to detect the peak value, and a comparator to compare the peak value detected by
the peak detecting circuit with each of the upper limit and the lower limit of the frequency
range. When the oscillation frequency falls within the predetermined frequency range,
this situation can be deemed that no degradation occurs in the sealing member 14. In
5 contrast, when the oscillation frequency does not fall within the predetermined frequency
range, this situation implies big vibration of the cover 11 and can be deemed that any
degradation occurs in the sealing member 14.
[0029] The frequency range is defined on the basis of possible values of the
oscillation frequency calculated from the values measured by the first vibration sensor 13,
10 in the case where the cover 11 is considered to be certainly closed in view of the
parameters, such as the air tightness necessary for the in-vehicle device 1, the material of
the sealing member 14, and the materials of the housing 10 and the cover 11. In detail,
possible values of the oscillation frequency calculated from the values measured by the
first vibration sensor 13 in the case where the cover 11 is considered to be certainly
15 closed are calculated on the basis of simulations or test runs, and a value range
encompassing the calculated possible values of the oscillation frequency is applied as the
frequency range.
[0030] When the determination circuit 43 determines that the oscillation frequency
does not fall within the predetermined range, the communication circuit 44 transmits a
20 determination result indicating that any degradation occurs in the sealing member 14 to
the train information management system 91. The train information management
system 91 is an in-vehicle system to control devices, such as a power conversion
apparatus, air conditioners, and lighting equipment. When the train information
management system 91 receives the determination result indicating that any degradation
25 occurs in the sealing member 14 from the degradation determiner 31, the train
information management system 91 causes a display device of a cab to display the
determination result or transmits the determination result to a monitoring system installed
11
in a direction center.
[0031] The control circuit 45 controls the initiation, termination, and
synchronization of processes of the individual components of the degradation determiner
31, that is, the sampling circuit 41, the FFT circuit 42, the determination circuit 43, and
5 the communication circuit 44.
[0032] As illustrated in FIG. 6, the degradation determiner 31 is achieved by a
processor 61, a memory 62, and an interface 63. The processor 61, the memory 62, and
the interface 63 are connected to each other via buses 60. The processor 61 is connected
to each of the first vibration sensor 13 and the train information management system 91
10 via the buses 60 and the interface 63. The process of determining the occurrence of
degradation executed by the degradation determiner 31 is achieved by the processor 61
executing a program stored in the memory 62.
[0033] The interface 63 serves to connect the degradation determiner 31 to each of
the first vibration sensor 13 and the train information management system 91 and
15 establish connection therebetween. The interface 63 is pursuant to multiple types of
interface standards as necessary. Although the degradation determiner 31 includes a
single processor 61 and a single memory 62 in the example illustrated in FIG. 6, the
degradation determiner 31 may include multiple processors 61 and multiple memories
62.
20 [0034] The following description is directed to a degradation determining process
executed by the degradation determiner 31 of the in-vehicle device 1 having the
above-described configuration.
After the closing and fastening of the cover 11 and the start of running of the
vehicle, the degradation determiner 31 initiates the degradation determining process
25 illustrated in FIG. 7. For example, an interlock mechanism is preferably provided to
allow a contactor to be closed and electrically connect the electronic equipment 71
accommodated in the housing 10 to a power source only when the cover 11 is closed and
12
fastened. In this case, in response to the closing and fastening of the cover 11 and the
closing of the contactor, the electronic equipment 71 is connected to the power source
and feeds electric power to the degradation determiner 31. In other words, the
degradation determiner 31 is preferably allowed to execute the degradation determining
5 process when the cover 11 is closed and fastened. Examples of the method for fastening
the closed cover 11 include fixation by means of a latching mechanism, and engagement
of the cover 11 with the housing 10.
[0035] The vibration of the cover 11 becomes big during acceleration or
deceleration of the vehicle in comparison to that during coasting of the vehicle. In order
10 to avoid erroneous determination of occurrence of degradation in the sealing member 14
on the basis of the mechanical vibration of the cover 11 during acceleration or
deceleration of the vehicle, the degradation determiner 31 preferably determines whether
any degradation occurs in the sealing member 14 on the basis of the mechanical vibration
measured by the first vibration sensor 13 during coasting of the vehicle. The
15 degradation determiner 31 in Embodiment 1 thus acquires a driving instruction for
designating an acceleration of the vehicle from the train information management system
91 and then determines whether the vehicle is coasting on the basis of the driving
instruction. When determining that the vehicle is coasting, the degradation determiner
31 determines whether any degradation occurs in the sealing member 14.
20 [0036] The driving instruction is input to the train information management system
91 in response to a manipulation on a master controller installed in the cab. Specifically,
the driving instruction may include a power running instruction for instructing the vehicle
to increase the speed or a braking instruction for instructing the vehicle to decrease the
speed, or may include neither of the power running instruction and the braking instruction.
25 The power running instruction designates a positive acceleration, and the braking
instruction designates a negative acceleration. When the driving instruction does not
include the power running instruction or the braking instruction, the vehicle can be
13
deemed to be coasting.
[0037] The degradation determining process executed by the degradation
determiner 31 is described in detail below with reference to FIG. 7.
At the initiation of the degradation determining process, the communication circuit
5 44 acquires a driving instruction from the train information management system 91 (Step
S11). When the driving instruction includes a power running instruction or a braking
instruction (Step S12; Yes), the communication circuit 44 repeats Step S11. In contrast,
when the driving instruction does not include the power running instruction or the
braking instruction (Step S12; No), the sampling circuit 41 acquires measured values
10 from the first vibration sensor 13, and samples a value measured by the first vibration
sensor 13 every sampling period (Step S13).
[0038] The FFT circuit 42 executes FFT on the values measured by the first
vibration sensor 13 and sampled in Step S13, and thereby generates a piece of
frequency-domain data (Step S14). The determination circuit 43 calculates an
15 oscillation frequency from the piece of frequency-domain data generated in Step S14
(Step S15).
[0039] The determination circuit 43 determines whether the oscillation frequency
calculated in Step S15 falls within the predetermined frequency range. When the
oscillation frequency calculated in Step S15 falls within the frequency range (Step S16;
20 Yes), the individual components of the degradation determiner 31 repeat the
above-described steps from Step S11.
[0040] In contrast, the oscillation frequency calculated in Step S15 does not fall
within the predetermined range (Step S16; No), the communication circuit 44 transmits a
determination result to the train information management system 91 (Step S17). In
25 detail, the communication circuit 44 transmits a determination result indicating that any
degradation occurs in the sealing member 14 to the train information management system
91. After completion of Step S17, the degradation determiner 31 terminates the
14
degradation determining process.
[0041] As described above, the degradation determiner 31 included in the
in-vehicle device 1 according to Embodiment 1 determines whether any degradation
occurs in the sealing member 14 on the basis of the mechanical vibration measured by the
5 first vibration sensor 13 while the cover 11 is closed. The degradation determiner 31
then transmits a determination result to the train information management system 91.
This configuration can maintain the waterproofness and dust resistance of the in-vehicle
device 1. In detail, the in-vehicle device 1 determines whether any degradation occurs
in the sealing member 14, and suggests maintenance involving replacement of the sealing
10 member 14 when any degradation occurs in the sealing member 14. This configuration
can inhibit contaminants, such as dust and water drops, from entering the in-vehicle
device 1 due to degradation of the sealing member 14.
[0042] The frequency range applied to determination of occurrence of degradation
in the sealing member 14 may be defined depending on the oscillation frequency of the
15 mechanical vibration of the cover 11 in the state where the air tightness necessary for the
housing 10 of the in-vehicle device 1 is achieved despite of occurrence of degradation in
the sealing member 14. This configuration can determine whether any degradation
occurs in the sealing member 14 at the stage before losing the air tightness necessary for
the housing 10. The configuration can suggest maintenance involving replacement of
20 the sealing member 14 before losing the air tightness necessary for the housing 10.
[0043] Embodiment 2
The first vibration sensor 13 is not necessarily disposed at the position in the
example illustrated in Embodiment 1 and may also be disposed at any position provided
that the first vibration sensor 13 can measure mechanical vibration of any cover included
25 in the in-vehicle device. The description of Embodiment 2 is directed to an in-vehicle
device 2 further including a first vibration sensor 18 disposed at a position different from
that in Embodiment 1.
15
[0044] As illustrated in FIG. 8, the in-vehicle device 2 includes the housing 10, the
cover 11, and the two support members 12, as in Embodiment 1. As illustrated in FIG.
9, which is a perspective view of the in-vehicle device 2 after removal of the cover 11, the
in-vehicle device 2 includes the sealing member 14, as in Embodiment 1. The
5 in-vehicle device 2 further includes an openable and closable cover 16 disposed over an
opening 10c provided to the housing 10 and the circumference of the opening 10c, a
support member 17 having the same shape as the support members 12 to support the
cover 16, a first vibration sensor 18 to measure vibration of the cover 16, and a sealing
member 19 disposed around the opening 10c such that the sealing member 19 is held
10 between the housing 10 and the cover 16 when the cover 16 is closed.
[0045] The sealing members 14 and 19 are made of the same material. The
sealing member 19 has a groove to engage with the edge of the opening 10c, like the
sealing member 14. The sealing members 14 and 19 are thus expected to degrade at the
same rate.
15 [0046] In the case where no degradation with age occurs in the sealing member 19,
the sealing member 19 held and pressed between the housing 10 and the cover 16 while
the cover 16 is closed has a sufficiently high resilience. This configuration can prevent
a gap from being formed between the cover 16 and the housing 10. This structure with
no gap can inhibit contaminants, such as dust and water drops, from entering the housing
20 10 through the opening 10c.
[0047] Unfortunately, when the resilience of the sealing member 19 decreases due
to degradation with age, for example, a gap is formed between the sealing member 19
and the cover 16 or the housing 10 while the cover 16 is closed. This gap may allow
contaminants, such as dust and water drops, to enter the housing 10 through the opening
25 10c.
[0048] When a gap is formed between the sealing member 19 and the cover 16 or
the housing 10, the mechanical vibration of the cover 16 during running of the vehicle
16
becomes bigger than that in the case of no gap between the sealing member 19 and the
cover 16 or the housing 10. In view of these facts, the in-vehicle device 2 further
includes a degradation determiner 32, which is described below, to determine whether
any degradation occurs in the sealing member 19 on the basis of the mechanical vibration
5 measured by the first vibration sensor 18 while the cover 16 is closed. Since the sealing
members 14 and 19 are expected to degrade at the same rate, the determination of
occurrence of degradation in the sealing member 19 can also achieve determination of
occurrence of degradation in the sealing member 14. The in-vehicle device 2 can
therefore determine whether any degradation occurs in the sealing members 14 and 19.
10 [0049] The individual components of the in-vehicle device 2 are described in detail
below.
As illustrated in FIG. 9, the side surface of the housing 10 included in the
in-vehicle device 2 has the opening 10c, separate from the opening 10a that allows for
maintenance of the electronic equipment 71 accommodated in the housing 10. The
15 opening 10c does not need to have the identical shape as the opening 10a. In the
example illustrated in FIG. 9, the opening 10c has a smaller area than the opening 10a.
[0050] As illustrated in FIGS. 8 and 9, the cover 16 is disposed over the opening
10c and the circumference of the opening 10c. The cover 16 has an outer surface 16a
that faces the outside of the housing 10, and the outer surface 16a is provided with an
20 engaging member 16b fixed with fastening members. The engaging member 16b has a
through hole, like the engaging member 11b. The engaging member 16b engages with
the support member 17 while the support member 17 is inserted in the through hole of the
engaging member 16b. The engaging member 16b is rotatable about a rotational axis
AX2 while the support member 17 is inserted in the through hole. The cover 16 is thus
25 supported by the support member 17 so as to be rotatable about the rotational axis AX2,
and openable and closable by rotating about the rotational axis AX2. In FIG. 8, the
rotational axis AX2 is represented by the dashed and double-dotted line. The rotational
17
axis AX2 extends in the X-axis direction, that is, the horizontal direction.
[0051] The cover 16 has an inner surface 16c that faces the inside of the housing 10,
and the inner surface 16c is provided with the first vibration sensor 18, as illustrated in
FIG. 10. FIG. 10 illustrates the cover 16 as viewed from the inside of the housing 10
5 while the cover 16 is closed. The cover 16 is preferably made of the same material as
the cover 11.
[0052] The support member 17 is fixed with fastening members on the surface of
the housing 10 provided with the opening 10a, like the support member 12. Specifically,
the support member 17 is disposed at a position above the opening 10c in the vertical
10 direction. The support member 17 has protrusions extending in a direction away from
the housing 10, and each of the protrusions has a notch. The protrusions of the support
member 17 are inserted in the through hole of the engaging member 16b and the
engaging member 16b engages with the notches of the support member 17, so that the
support member 17 supports the cover 16 such that the cover 16 is rotatable about the
15 rotational axis AX2.
[0053] The first vibration sensor 18 has the configuration identical to that of the
first vibration sensor 13. The first vibration sensor 18 is mounted on the cover 16 and
measures mechanical vibration of the cover 16. In detail, the first vibration sensor 18 is
mounted on the inner surface 16c of the cover 16 in a vertically bottom portion.
20 [0054] The first vibration sensor 18 is connected to the cable 15. The first
vibration sensor 18 is fed with electric power and transmits measured values to the
degradation determiner 32 via the cable 15. The first vibration sensor 18 is preferably
fed with electric power from the electronic equipment 71.
[0055] The degradation determiner 32 is accommodated in the housing 10, and
25 determines whether any degradation occurs in the sealing member 19 on the basis of the
measured values of the mechanical vibration of the cover 16. In detail, as illustrated in
FIG. 11, the degradation determiner 32 includes a sampling circuit 41 to sample values
18
measured by the first vibration sensor 18, a comparison circuit 46 to determine whether
the sampled values measured by the first vibration sensor 18 exceed an amplitude
threshold, a counter circuit 47 to determine whether the number of times that the
comparison circuit 46 determines the sampled values to exceed the amplitude threshold is
5 larger than a predetermined number of times, a communication circuit 44 to transmit a
determination result to the train information management system 91, and a control circuit
45 to control the individual components of the degradation determiner 32.
[0056] The individual components of the degradation determiner 32 are described
in detail below.
10 The sampling circuit 41 samples a value measured by the first vibration sensor 18
every predetermined sampling period, as in Embodiment 1, and outputs the sampled
values measured by the first vibration sensor 18 to the comparison circuit 46.
[0057] The comparison circuit 46 determines whether the sampled values
measured by the first vibration sensor 18 exceed the amplitude threshold, and outputs a
15 determination result to the counter circuit 47. For example, the comparison circuit 46
provides the counter circuit 47 with a determination result signal, which indicates 1 when
a sampled value measured by the first vibration sensor 18 exceeds the amplitude
threshold and indicates 0 when a sampled value measured by the first vibration sensor 18
is equal to or lower than the amplitude threshold.
20 [0058] The amplitude threshold is defined on the basis of possible values measured
by the first vibration sensor 18 in the case where the cover 16 is considered to be certainly
closed in view of the parameters, such as the air tightness necessary for the in-vehicle
device 2, the material of the sealing member 19, and the materials of the housing 10 and
the cover 16. In detail, possible values measured by the first vibration sensor 18 in the
25 case where the cover 16 is considered to be certainly closed are calculated on the basis of
simulations or test runs, and a value higher than the calculated possible values measured
by the first vibration sensor 18 is applied as the amplitude threshold.
19
[0059] The counter circuit 47 counts the number of times that the sampled values
measured by the first vibration sensor 18 exceed the amplitude threshold within a unit
time, and determines whether the counted number is larger than the predetermined
number of times. In detail, the counter circuit 47 accumulates the number of times that
5 the comparison circuit 46 determines the sampled values to exceed the amplitude
threshold within a unit time, and determines whether the accumulated number is larger
than the predetermined number of times. For example, the counter circuit 47 includes
an accumulator to accumulate values indicated by determination result signals received
from the comparison circuit 46 within a unit time, and a comparator to compare a result
10 of accumulation performed by the accumulator with the predetermined number of times.
[0060] When the number of times that the sampled values measured by the first
vibration sensor 18 exceed the amplitude threshold within a unit time is equal to or
smaller than the predetermined number of times, this situation can be deemed that no
degradation occurs in the sealing member 19. The situation can also be deemed that no
15 degradation occurs in the sealing member 14, which is expected to degrade at the same
rate as the sealing member 19. In contrast, when the number of times that the sampled
values measured by the first vibration sensor 18 exceed the amplitude threshold is larger
than the predetermined number of times, this situation implies big vibration of the cover
16 and can be deemed that any degradation occurs in the sealing member 19. The
20 situation can also be deemed that any degradation occurs in the sealing member 14,
which is expected to degrade at the same rate as the sealing member 19.
[0061] The unit time can be any time that is at least the time necessary for acquiring
an amount of sampled values measured by the first vibration sensor 18 sufficient for
determination of occurrence of degradation in the sealing member 19 on the basis of the
25 values measured by the first vibration sensor 18. The predetermined number of times
may be any value equal to or higher than two so as not to mistake a sudden variation in
the values measured by the first vibration sensor 18 as occurrence of degradation in the
20
sealing member 19.
[0062] When the counter circuit 47 determines that the number of times that the
values exceed the amplitude threshold within a unit time is larger than the predetermined
number of times, the communication circuit 44 transmits a determination result indicating
5 that any degradation occurs in the sealing members 14 and 19 to the train information
management system 91.
[0063] The control circuit 45 controls the initiation, termination, and
synchronization of processes of the individual components of the degradation determiner
32, that is, the sampling circuit 41, the comparison circuit 46, the counter circuit 47, and
10 the communication circuit 44.
[0064] The degradation determiner 32 has the hardware configuration identical to
that of the degradation determiner 31. The degradation determiner 32 is connected to
the first vibration sensor 18 and the train information management system 91 via the
interface 63.
15 [0065] The following description is directed to a degradation determining process
executed by the degradation determiner 32 of the in-vehicle device 2 having the
above-described configuration.
After the start of running of the vehicle, the degradation determiner 32 initiates the
degradation determining process illustrated in FIG. 12. For example, an interlock
20 mechanism is preferably provided to allow a contactor to be closed and electrically
connect the electronic equipment 71 accommodated in the housing 10 to the power
source only when the covers 11 and 16 are closed and fastened. In this case, in response
to the closing and fastening of the covers 11 and 16 and the closing of the contactor, the
electronic equipment 71 is connected to the power source and feeds electric power to the
25 degradation determiner 32. In other words, the degradation determiner 32 is preferably
allowed to execute the degradation determining process when the covers 11 and 16 are
closed and fastened.
21
[0066] When the in-vehicle device 2 accommodates a device, such as fan, which
generates vibration while the vehicle is standing still, the degradation determiner 32 can
determine whether any degradation occurs in the sealing member 19 on the basis of the
mechanical vibration measured by the first vibration sensor 18 while the vehicle is
5 standing still. The degradation determiner 32 in Embodiment 2 thus determines
whether any degradation occurs in the sealing member 19 on the basis of the mechanical
vibration measured by the first vibration sensor 18 while the vehicle is coasting or
standing still. In detail, the degradation determiner 32 acquires a driving instruction and
the speed of the vehicle from the train information management system 91, and
10 determines whether the vehicle is coasting and whether the vehicle is standing still.
When the vehicle is coasting or standing still, the degradation determiner 32 determines
whether any degradation occurs in the sealing member 19.
[0067] The degradation determining process executed by the degradation
determiner 32 is described in detail below with reference to FIG. 12.
15 At the initiation of the degradation determining process, the communication circuit
44 acquires a driving instruction from the train information management system 91 (Step
S21). The communication circuit 44 also acquires the speed of the vehicle from the
train information management system 91 (Step S22). When the driving instruction
includes a power running instruction or a braking instruction and when the vehicle is
20 running (Step S23; Yes), the communication circuit 44 repeats Steps S21 and S22. In
contrast, when the driving instruction does not include the power running instruction or
the braking instruction or when the vehicle is not running (Step S23; No), the sampling
circuit 41 acquires measured values from the first vibration sensor 18 and samples a value
measured by the first vibration sensor 13 every sampling period (Step S24).
25 [0068] The comparison circuit 46 determines whether the values measured by the
first vibration sensor 18 and sampled in Step S24 exceed the amplitude threshold. The
counter circuit 47 then counts the number of times that the comparison circuit 46
22
determines the sampled values to exceed the amplitude threshold within a unit time (Step
S25). When the counted result in Step S25 is equal to or smaller than the predetermined
number of times (Step S26; Yes), the individual components of the degradation
determiner 32 repeat the above-described steps from Step S21.
5 [0069] In contrast, when the counted result in Step S25 exceeds the predetermined
number of times (Step S26; No), the communication circuit 44 transmits a determination
result to the train information management system 91 (Step S27). In detail, the
communication circuit 44 transmits a determination result indicating that any degradation
occurs in the sealing members 14 and 19 to the train information management system 91.
10 After completion of Step S27, the degradation determiner 32 terminates the degradation
determining process.
[0070] As described above, the degradation determiner 32 included in the
in-vehicle device 2 according to Embodiment 2 determines whether any degradation
occurs in the sealing member 19 on the basis of the mechanical vibration measured by the
15 first vibration sensor 18 while the cover 16 is closed. Since the sealing member 14 is
expected to degrade at the same rate as the sealing member 19, the determination of
occurrence of degradation in the sealing member 19 can also achieve determination of
occurrence of degradation in the sealing member 14. The degradation determiner 32
then transmits a determination result to the train information management system 91.
20 This configuration can maintain the waterproofness and dust resistance of the in-vehicle
device 2. In detail, the in-vehicle device 2 determines whether any degradation occurs
in the sealing member 19, and suggests maintenance involving replacement of the sealing
members 14 and 19 when any degradation occurs in the sealing member 19. This
configuration can inhibit contaminants, such as dust and water drops, from entering the
25 in-vehicle device 2 due to degradation in the sealing members 14 and 19.
[0071] The opening 10c is designed to have a size smaller than the opening 10a,
thereby reducing the size of the cover 16 in comparison to the cover 11. Accordingly,
23
the ratio of the area of the cover 16 in contact with the sealing member 19 to the entire
area of the cover 16 is higher than that of the cover 11. The degradation of the sealing
member 19 thus more significantly affects the vibration of the cover 16 than that of the
cover 11. The degradation determiner 32 can therefore more accurately determine
5 whether any degradation occurs in the sealing member 19 in comparison to the
degradation determiner 31.
[0072] Embodiment 3
The occurrence of degradation in the sealing member 14 may also be determined
on the basis of the values measured by multiple vibration sensors. The following
10 description of Embodiment 3 is directed to an in-vehicle device 3 to determine whether
any degradation occurs in the sealing member 14 on the basis of the respective values
measured by the first vibration sensor 13 and a second vibration sensor 20.
[0073] As illustrated in FIG. 13 and FIG. 14, which is a partial sectional view taken
along the line B-B of FIG. 13, the in-vehicle device 3 includes the housing 10, the cover
15 11, the two support members 12, the first vibration sensor 13, and the sealing member 14,
as in Embodiment 1. The in-vehicle device 3 further includes the second vibration
sensor 20 to measure mechanical vibration of the housing 10.
[0074] In the case where no degradation with age occurs in the sealing member 14,
the sealing member 14 held and pressed between the housing 10 and the cover 11 while
20 the cover 11 is closed has a sufficiently high resilience. As illustrated in FIG. 14, this
configuration can prevent a gap from being formed between the cover 11 and the housing
10. This structure with no gap can inhibit contaminants, such as dust and water drops,
from entering the housing 10 through the opening 10a. FIG. 14 does not illustrate the
electronic equipment 71.
25 [0075] Unfortunately, when the resilience of the sealing member 14 decreases due
to degradation with age, for example, a gap is formed between the sealing member 14
and the cover 11 or the housing 10 while the cover 11 is closed. This gap may allow
24
contaminants, such as dust and water drops, to enter the housing 10 through the opening
10a.
[0076] When a gap is formed between the sealing member 14 and the cover 11 or
the housing 10, the mechanical vibration of the cover 11 during running of the vehicle
5 becomes bigger than the mechanical vibration of the housing 10. In view of these facts,
the in-vehicle device 3 further includes a degradation determiner 33, which is described
below, to determine whether any degradation occurs in the sealing member 14 on the
basis of the mechanical vibration measured by the first vibration sensor 13 and the second
vibration sensor 20 while the cover 11 is closed. The in-vehicle device 3 can therefore
10 determine whether any degradation occurs in the sealing member 14.
[0077] The individual components of the in-vehicle device 3 are described in detail
below.
The second vibration sensor 20 is mounted on the housing 10 and measures
mechanical vibration of the housing 10. A typical example of the second vibration
15 sensor 20 is a contact-type acceleration sensor. In detail, the second vibration sensor 20
is mounted on the inner surface of the housing 10 in a vertically top portion.
[0078] The second vibration sensor 20 is connected to a cable 21. The second
vibration sensor 20 is fed with electric power and transmits measured values to the
degradation determiner 33 via the cable 21. The second vibration sensor 20 is
20 preferably fed with electric power from the electronic equipment 71.
[0079] The degradation determiner 33 is accommodated in the housing 10 and
determines whether any degradation occurs in the sealing member 14 on the basis of the
mechanical vibration of the cover 11 and the mechanical vibration of the housing 10.
For example, the degradation determiner 33 determines whether any degradation occurs
25 in the sealing member 14 on the basis of the difference between the maximum amplitude
of the mechanical vibration of the cover 11 and the maximum amplitude of the
mechanical vibration of the housing 10.
25
[0080] In detail, as illustrated in FIG. 15, the degradation determiner 33 includes a
sampling circuit 41 to sample the respective values measured by the first vibration sensor
13 and the second vibration sensor 20, a difference circuit 48 to calculate the difference
between the maximum value of the sampled values measured by the first vibration sensor
5 13 and the maximum value of the sampled values measured by the second vibration
sensor 20, a determination circuit 49 to determine whether the difference calculated by
the difference circuit 48 falls within a predetermined difference range, a communication
circuit 44 to transmit a result of determination performed by the determination circuit 49
to the train information management system 91, and a control circuit 45 to control the
10 individual components of the degradation determiner 33. The degradation determiner
33 has the hardware configuration identical to that of the degradation determiner 31.
The degradation determiner 33 is connected to the first vibration sensor 13, the second
vibration sensor 20, and the train information management system 91 via the interface 63.
[0081] The individual components of the degradation determiner 33 are described
15 in detail below.
The sampling circuit 41 samples a value measured by the first vibration sensor 13
every predetermined sampling period. The sampling circuit 41 also samples a value
measured by the second vibration sensor 20 every predetermined sampling period. The
sampling circuit 41 then outputs the sampled values measured by the first vibration
20 sensor 13 and the sampled values measured by the second vibration sensor 20 to the
difference circuit 48.
[0082] The difference circuit 48 calculates the maximum value of the sampled
values measured by the first vibration sensor 13 and the maximum value of the sampled
values measured by the second vibration sensor 20 within a unit time. The difference
25 circuit 48 then calculates the difference between the maximum value of the sampled
values measured by the first vibration sensor 13 and the maximum value of the sampled
values measured by the second vibration sensor 20, and outputs the calculated difference
26
to the determination circuit 49. The unit time may be any time that is at least the time
necessary for acquiring amounts of sampled values measured by the first vibration sensor
13 and sampled values measured by the second vibration sensor 20 sufficient for
determination of occurrence of degradation in the sealing member 14 on the basis of the
5 respective values measured by the first vibration sensor 13 and the second vibration
sensor 20.
[0083] The determination circuit 49 determines whether the difference calculated
by the difference circuit 48 falls within the predetermined difference range. For
example, the determination circuit 49 includes a comparator to compare the difference
10 calculated by the difference circuit 48 with each of the upper limit and the lower limit of
the difference range. When the difference calculated by the difference circuit 48 falls
within the difference range, this situation implies that the vibration of the cover 11 is not
bigger than the vibration of the housing 10 and can be deemed that no degradation occurs
in the sealing member 14. In contrast, when the difference calculated by the difference
15 circuit 48 does not fall within the difference range, this situation implies that the vibration
of the cover 11 is bigger than the vibration of the housing 10 and can be deemed that any
degradation occurs in the sealing member 14.
[0084] The difference range is defined on the basis of possible values of the
difference between the maximum value of the values measured by the first vibration
20 sensor 13 and the maximum value of the values measured by the second vibration sensor
20, in the case where the cover 11 is considered to be certainly closed in view of the
parameters, such as the air tightness necessary for the in-vehicle device 3, the material of
the sealing member 14, and the materials of the housing 10 and the cover 11. In detail,
possible values of the difference between the value measured by the first vibration sensor
25 13 and the value measured by the second vibration sensor 20 in the case where the cover
11 is considered to be certainly closed are calculated on the basis of simulations or test
runs, and a value range encompassing the possible values of the difference between the
27
maximum value of the values measured by the first vibration sensor 13 and the maximum
value of the values measured by the second vibration sensor 20 is applied as the
difference range.
[0085] When the determination circuit 49 determines that the difference calculated
5 by the difference circuit 48 does not fall within the difference range, the communication
circuit 44 transmits a determination result indicating that any degradation occurs in the
sealing member 14 to the train information management system 91.
[0086] The control circuit 45 controls the initiation, termination, and
synchronization of processes of the individual components of the degradation determiner
10 33, that is, the sampling circuit 41, the difference circuit 48, the determination circuit 49,
and the communication circuit 44.
[0087] The following description is directed to a degradation determining process
executed by the degradation determiner 33 of the in-vehicle device 3 having the
above-described configuration.
15 After the start of running of the vehicle, the degradation determiner 33 initiates the
degradation determining process illustrated in FIG. 16. For example, an interlock
mechanism is preferably provided to allow a contactor to be closed and electrically
connect the electronic equipment 71 accommodated in the housing 10 to the power
source only when the cover 11 is closed and fastened. In this case, in response to the
20 closing and fastening of the cover 11 and the closing of the contactor, the electronic
equipment 71 is connected to the power source and feeds electric power to the
degradation determiner 33. In other words, the degradation determiner 33 is preferably
allowed to execute the degradation determining process when the cover 11 is closed and
fastened.
25 [0088] The mechanical vibration of the cover 11 caused by running of the vehicle
significantly varies during sliding of the vehicle. The sliding of the vehicle occurs
because of a decrease in friction coefficient of the contact surface between wheels and
28
rails. Some of the causes of such a decrease in friction coefficient are environmental
factors, such as a place where the vehicle is running, ambient temperature, and weather.
In order to avoid erroneous determination of occurrence of degradation in the sealing
member 14 on the basis of the mechanical vibration of the cover 11 during sliding of the
5 vehicle, the degradation determiner 33 preferably determines whether any degradation
occurs in the sealing member 14 when the vehicle is less likely to slide in view of the
environmental factors. The degradation determiner 33 in Embodiment 3 thus acquires
pieces of environmental information containing at least one of the place where the vehicle
is running, the ambient temperature outside the housing 10, and the weather, and
10 determines whether any degradation occurs in the sealing member 14 when the
environmental conditions defined for the respective pieces of environmental information
are satisfied.
[0089] For example, the degradation determiner 33 may preliminarily retain the
condition that the vehicle is located in a straight course, as the environmental condition
15 related to the place where the vehicle is running. The degradation determiner 33 may
also preliminarily retain the condition of the ambient temperature of at least 20°C and at
most 25°C, as the environmental condition related to the ambient temperature. The
degradation determiner 33 may also preliminarily retain the condition of the sunny
weather, as the environmental condition related to the weather. In this case, when the
20 vehicle is running in a straight course and when the ambient temperature is at least 20°C
and at most 25°C and when the weather is sunny, the degradation determiner 33 may
determine whether any degradation occurs in the sealing member 14.
[0090] The degradation determining process executed by the degradation
determiner 33 is described in detail below with reference to FIG. 16.
25 At the initiation of the degradation determining process, the communication circuit
44 acquires pieces of environmental information from the train information management
system 91 (Step S31). When the environmental conditions defined for the respective
29
pieces of environmental information are not satisfied (Step S32; No), the communication
circuit 44 repeats Step S31. In contrast, when the environmental conditions defined for
the respective pieces of environmental information are satisfied (Step S32; Yes), the
sampling circuit 41 acquires the respective values measured by the first vibration sensor
5 13 and the second vibration sensor 20, and samples a value measured by the first
vibration sensor 13 and a value measured by the second vibration sensor 20 every
sampling period (Step S33).
[0091] The difference circuit 48 calculates the maximum value of the sampled
values measured by the first vibration sensor 13 and the maximum value of the sampled
10 values measured by the second vibration sensor 20 within a unit time, and calculates the
difference between the maximum value of the sampled values measured by the first
vibration sensor 13 and the maximum value of the sampled values measured by the
second vibration sensor 20 (Step S34).
[0092] The determination circuit 49 determines whether the difference calculated in
15 Step S34 falls within the predetermined difference range. When the difference
calculated in Step S34 falls within the difference range (Step S35; Yes), the individual
components of the degradation determiner 33 repeat the above-described steps from Step
S31.
[0093] In contrast, when the difference calculated in Step S34 does not fall within
20 the difference range (Step S35; No), the communication circuit 44 transmits a
determination result to the train information management system 91 (Step S36). In
detail, the communication circuit 44 transmits a determination result indicating that any
degradation occurs in the sealing member 14 to the train information management system
91. After completion of Step S36, the degradation determiner 33 terminates the
25 degradation determining process.
[0094] As described above, the degradation determiner 33 included in the
in-vehicle device 3 according to Embodiment 3 determines whether any degradation
30
occurs in the sealing member 14 on the basis of the mechanical vibration measured by the
first vibration sensor 13 and the second vibration sensor 20 while the cover 11 is closed.
Since the determination of occurrence of degradation in the sealing member 19 is
executed on the basis of the respective values measured by the first vibration sensor 13
5 and the second vibration sensor 20, occurrence of degradation in the sealing member 14
can be determined even during acceleration or deceleration of the vehicle.
[0095] The degradation determiner 33 determines whether any degradation occurs
in the sealing member 14 when the vehicle is less likely to slide in view of the
environmental information. This configuration can improve the accuracy of
10 determination of occurrence of degradation in the sealing member 14.
[0096] Embodiment 4
The above-described degradation determining process is a mere example. The
description of Embodiment 4 is directed to an in-vehicle device 4 to determine whether
any degradation occurs in sealing members 25 on the basis of values measured by first
15 vibration sensors 24 mounted on respective covers 22.
[0097] As illustrated in FIG. 17, the in-vehicle device 4 includes the housing 10, the
openable and closable covers 22, and support members 23 each having the same shape as
the support member 12 to support each of the covers 22, and the first vibration sensors 24
to measure mechanical vibration of the respective covers 22. FIG. 17 can be understood
20 like FIG. 1. As illustrated in FIG. 18, which is a perspective view of the in-vehicle
device 4 after removal of the covers 22, the housing 10 has multiple openings 10d. FIG.
18 can be understood like FIG. 2. As illustrated in FIG. 18, the in-vehicle device 4
further includes the sealing members 25 each of which is disposed around each of the
openings 10d such that the sealing member 25 is held between the housing 10 and each
25 of the covers 22 when the cover 22 is closed, and restricting members 22d to restrict
movement of the covers 22 while the covers 22 are closed.
[0098] In the case where no degradation with age occurs in the sealing members 25,
31
each of the sealing members 25 held between the housing 10 and each of the covers 22
while the cover 22 is closed has a sufficiently high resilience. This configuration can
prevent a gap from being formed between each of the covers 22 and the housing 10.
This structure with no gap can inhibit contaminants, such as dust and water drops, from
5 entering the housing 10 through each of the openings 10d.
[0099] Unfortunately, when the resilience of each of the sealing members 25
decreases due to degradation with age, for example, a gap is formed between each of the
sealing members 25 and each of the covers 22 or the housing 10 while the cover 22 is
closed. This gap may allow contaminants, such as dust and water drops, to enter the
10 housing 10 through each of the openings 10d. The individual sealing members 25 have
the identical shape and are made of the same material, and are therefore expected to
degrade at the same rate.
[0100] When a gap is formed between each of the sealing members 25 and each of
the covers 22 or the housing 10, the mechanical vibration of the cover 22 during running
15 of the vehicle becomes bigger than that in the case of no gap between the sealing member
25 and the cover 22 or the housing 10. In view of these facts, the in-vehicle device 4
further includes a degradation determiner 34, which is described below, to determine
whether any degradation occurs in the sealing members 25 on the basis of the mechanical
vibration measured by the individual first vibration sensors 24 while the covers 22 are
20 closed. The in-vehicle device 4 can therefore determine whether any degradation occurs
in the sealing members 25.
[0101] The individual components of the in-vehicle device 4 are described in detail
below.
As illustrated in FIG. 18, the side surface of the housing 10 is provided with three
25 openings 10d. These openings 10d allow for maintenance of the electronic equipment
71 accommodated in the housing 10. The three openings 10d have the same size and
are arranged in the X-axis direction.
32
[0102] As illustrated in FIGS. 17 and 18, the covers 22 are disposed over the
respective openings 10d and the circumferences of the respective openings 10d. Each
of the covers 22 has an outer surface 22a that faces the outside of the housing 10, and the
outer surface 22a is provided with an engaging member 22b fixed with fastening
5 members. The engaging member 22b has a through hole, like the engaging member
11b. The engaging member 22b engages with the support member 23 while the support
member 23 is inserted in the through hole of the engaging member 22b. The engaging
member 22b is rotatable about the rotational axis AX1 while the support member 23 is
inserted in the through hole. The covers 22 are thus supported by the respective support
10 members 23 so as to be rotatable about the rotational axis AX1, and openable and
closable by rotating about the rotational axis AX1.
[0103] Each of the covers 22 has an inner surface 22c that faces the inside of the
housing 10, and the inner surface 22c is provided with the first vibration sensor 24. The
covers 22 are preferably made of the same material.
15 [0104] Each of the covers 22 is also provided with the two restricting members 22d
to restrict movement of the cover 22 while the cover 22 is closed. When the cover 22 is
closed, the restricting members 22d can be rotated from the releasing positions to the
restricting positions. The restricting members 22d at the restricting positions engage
with the housing 10 and thereby restrict movement of the cover 22 while the cover 22 is
20 closed, although the detailed mechanism is not illustrated.
[0105] The support members 23 are fixed with fastening members on the surface of
the housing 10 provided with the openings 10d, like the support members 12.
Specifically, the support members 23 are disposed at positions above the respective
openings 10d in the vertical direction. Each of the support members 23 has protrusions
25 extending in a direction away from the housing 10, and each of the protrusions has a
notch. The protrusions of the support member 23 are inserted in the through hole of the
engaging member 22b and the engaging member 22b engages with the notches of the
33
support member 23, so that the support member 23 supports the corresponding cover 22
such that the cover 22 is rotatable about the rotational axis AX1.
[0106] Each of the first vibration sensors 24 has the configuration identical to that
of the first vibration sensor 13. The first vibration sensors 24 are mounted on the
5 respective covers 22 and measure mechanical vibrations of the respective covers 22.
[0107] The vibration of each of the covers 22 generated during running of the
vehicle varies depending on the position in the cover 22. Specifically, the vibration of
the cover 11 is bigger at a position more distant from the engaging member 22b
supported by the support member 23 and from the restricting members 22d to engage
10 with the housing 10 and thereby restrict movement of the cover 22. Each of the first
vibration sensors 24 is thus preferably disposed at a position at least a first distance away
from the support member 23 while the cover 22 is closed, as in Embodiment 1. In
addition, the first vibration sensor 24 is preferably disposed at a position at least a second
distance away from the restricting members 22d. The second distance is defined in
15 view of the parameters, such as the size of the cover 22 and the positions of the restricting
members 22d. For example, the second distance is defined to be equal to the half of the
length of the cover 22 in the transverse direction.
[0108] More preferably, each of the first vibration sensors 24 is mounted on the
inner surface 22c of the cover 22 at the position so as to maximize the sum of the distance
20 from the support member 23 and the distance from the restricting members 22d while the
cover 22 is closed, among the mountable positions in the inner surface 22c of the cover
22. In the example illustrated in FIG. 17, the first vibration sensor 24 is mounted on the
inner surface 22c of the cover 22 at a position in the center in the X-axis direction and in
the center in the Z-axis direction.
25 [0109] The first vibration sensors 24 are fed with electric power and transmit
measured values to the degradation determiner 34 via a cable, which is not illustrated, as
in Embodiment 1. The first vibration sensors 24 are preferably fed with electric power
34
from the electronic equipment 71.
[0110] Each of the sealing members 25 has a groove to engage with the edge of
each of the openings 10d, as in Embodiment 1. The sealing member 25 is thus attached
to the housing 10 while being disposed around the opening 10d. When the covers 22
5 are closed, the sealing members 25 are held between the housing 10 and the respective
covers 22. The sealing members 25 are made of a material resilient to pressure, such as
synthetic rubber or resin, for example.
[0111] The degradation determiner 34 is accommodated in the housing 10, and
determines whether any degradation occurs in the sealing members 25 on the basis of the
10 average calculated from the oscillation frequencies of the mechanical vibration of the
respective covers 22. In detail, as illustrated in FIG. 19, the degradation determiner 34
includes a sampling circuit 41 to sample the respective values measured by the first
vibration sensors 24, an FFT circuit 42 to generate pieces of frequency-domain data from
the sampled values measured by the first vibration sensors 24, and an average circuit 50
15 to calculate oscillation frequencies from the individual pieces of frequency-domain data
and calculate the average of the calculated oscillation frequencies, a determination circuit
51 to determine whether the average calculated by the average circuit 50 falls within a
predetermined average range, a communication circuit 44 to transmit a result of
determination executed by the determination circuit 51 to the train information
20 management system 91, and a control circuit 45 to control the individual components of
the degradation determiner 34. The degradation determiner 34 has the hardware
configuration identical to that of the degradation determiner 31. The degradation
determiner 34 is connected to the individual first vibration sensors 24 and the train
information management system 91 via the interface 63.
25 [0112] The individual components of the degradation determiner 34 are described
in detail below.
The sampling circuit 41 samples the respective values measured by the first
35
vibration sensors 24 every predetermined sampling period. The sampling circuit 41
then outputs the sampled values measured by the first vibration sensors 24 to the FFT
circuit 42.
[0113] The FFT circuit 42 executes FFT on the values measured by the first
5 vibration sensors 24 and sampled by the sampling circuit 41, and thereby generates pieces
of frequency-domain data. The FFT circuit 42 then outputs the pieces of
frequency-domain data to the average circuit 50.
[0114] The average circuit 50 calculates an oscillation frequency from the peak
value of each of the pieces of frequency-domain data. The average circuit 50 calculates
10 the average of the calculated oscillation frequencies, and outputs the calculated average to
the determination circuit 51. For example, the average circuit 50 includes a peak
detecting circuit to detect the peak values, an accumulator to accumulate the peak values
detected by the peak detecting circuit, and a divider to divide the values accumulated by
the accumulator by the number of first vibration sensors 24.
15 [0115] The determination circuit 51 determines whether the average of the
oscillation frequencies calculated by the average circuit 50 falls within the predetermined
average range. For example, the determination circuit 51 includes a comparator to
compare the average calculated by the average circuit 50 with each of the upper limit and
the lower limit of the average range. When the average of the oscillation frequencies
20 calculated by the average circuit 50 falls within the average range, this situation can be
deemed that no degradation occurs in each of the sealing members 25. In contrast,
when the average of the oscillation frequencies calculated by the average circuit 50 does
not fall within the average range, this situation implies big vibration of the covers 22 and
can be deemed that any degradation occurs in the sealing members 25.
25 [0116] The average range is defined on the basis of possible values of the average
of the oscillation frequencies calculated from the respective values measured by the first
vibration sensors 24, in the case where the covers 22 are considered to be certainly closed
36
in view of the parameters, such as the air tightness necessary for the in-vehicle device 4,
the material of the sealing members 25, and the materials of the housing 10 and the
covers 22. In detail, possible values of the oscillation frequencies calculated from the
respective values measured by the first vibration sensors 24 in the case where the covers
5 22 are considered to be certainly closed are calculated on the basis of simulations or test
runs, and a value range encompassing the possible values of the average of the oscillation
frequencies is applied as the average range.
[0117] When the determination circuit 51 determines that the average of the
oscillation frequencies does not fall within the average range, the communication circuit
10 44 transmits a determination result indicating that any degradation occurs in the sealing
members 25 to the train information management system 91.
[0118] The control circuit 45 controls the initiation, termination, and
synchronization of processes of the individual components of the degradation determiner
34, that is, the sampling circuit 41, the FFT circuit 42, the average circuit 50, the
15 determination circuit 51, and the communication circuit 44.
[0119] The following description is directed to a degradation determining process
executed by the degradation determiner 34 of the in-vehicle device 4 having the
above-described configuration.
After the start of running of the vehicle, the degradation determiner 34 initiates the
20 degradation determining process illustrated in FIG. 20. For example, an interlock
mechanism is preferably provided to allow a contactor to be closed and electrically
connect the electronic equipment 71 accommodated in the housing 10 to the power
source only when the covers 22 are closed and fastened. In this case, in response to the
closing and fastening of the covers 22 and the closing of the contactor, the electronic
25 equipment 71 is connected to the power source and feeds electric power to the
degradation determiner 34. In other words, the degradation determiner 34 is preferably
allowed to execute the degradation determining process when the individual covers 22
37
are closed and fastened.
[0120] In order to avoid erroneous determination of occurrence of degradation in
the sealing members 25 on the basis of mechanical vibration of the respective covers 22
during acceleration or deceleration of the vehicle, as in Embodiment 1, the degradation
5 determiner 34 preferably determines whether any degradation occurs in the sealing
members 25 on the basis of the mechanical vibration measured by the first vibration
sensors 24 during coasting of the vehicle. The degradation determiner 34 in
Embodiment 4 thus acquires a driving instruction for designating an acceleration of the
vehicle from the train information management system 91, and then determines whether
10 the vehicle is coasting on the basis of the driving instruction. When determining that the
vehicle is coasting, the degradation determiner 34 determines whether any degradation
occurs in the sealing members 25.
[0121] The degradation determining process executed by the degradation
determiner 34 is described in detail below with reference to FIG. 20.
15 At the initiation of the degradation determining process, the communication circuit
44 acquires a driving instruction from the train information management system 91 (Step
S41). When the driving instruction includes a power running instruction or a braking
instruction (Step S42; Yes), the communication circuit 44 repeats Step S41. In contrast,
when the driving instruction does not include the power running instruction or the
20 braking instruction (Step S42; No), the sampling circuit 41 acquires measured values
from the respective first vibration sensors 24, and samples the respective values measured
by the first vibration sensors 24 every sampling period (Step S43).
[0122] The FFT circuit 42 executes FFT on the respective values measured by the
first vibration sensors 24 and sampled in Step S43, and thereby generates pieces of
25 frequency-domain data (Step S44). The average circuit 50 calculates oscillation
frequencies from the respective pieces of frequency-domain data generated in Step S44
(Step S45). The average circuit 50 then calculates the average of the oscillation
38
frequencies calculated in Step S45 (Step S46).
[0123] The determination circuit 51 determines whether the average of the
oscillation frequencies calculated in Step S46 falls within the predetermined average
range. When the average of the oscillation frequencies calculated in Step S46 falls
5 within the average range (Step S47; Yes), the individual components of the degradation
determiner 34 repeat the above-described steps from Step S41.
[0124] In contrast, when the average calculated in Step S46 does not fall within the
average range (Step S47; No), the communication circuit 44 transmits a determination
result to the train information management system 91 (Step S48). In detail, the
10 communication circuit 44 transmits a determination result indicating that any degradation
occurs in the sealing members 25 to the train information management system 91. After
completion of Step S48, the degradation determiner 34 terminates the degradation
determining process.
[0125] As described above, the degradation determiner 34 included in the
15 in-vehicle device 4 according to Embodiment 4 determines whether any degradation
occurs in the sealing members 25 on the basis of the mechanical vibration measured by
the first vibration sensors 24 while covers 22 are closed. The degradation determiner 34
determines whether any degradation occurs in the sealing members 25 on the basis of the
average of the oscillation frequencies calculated from the sampled values measured by
20 the first vibration sensors 24. This configuration can avoid erroneous determination of
occurrence of degradation in the sealing members 25 due to differences in the
measurement accuracies between the first vibration sensors 24.
[0126] The above-described embodiments are not to be construed as limiting the
present disclosure. The above-mentioned hardware configurations and flowcharts are
25 mere examples and may be arbitrarily varied and modified.
[0127] The in-vehicle devices 1 to 4 may also be installed in any other vehicle, such
as automobile, marine vessel, or aircraft, as well as railway vehicle. The in-vehicle
39
devices 1 to 4 may also be provided at any other site, such as on the floor or on the roof,
as well as under the floor.
[0128] The housing 10 may have a shape other than those in the above-described
examples. In one example, the openings 10a, 10c, and 10d may also be provided on the
5 upper surface of the housing 10 in the vertical direction. In another example, the
opening 10c may be provided on a surface of the housing 10 different from the surface
provided with the opening 10a. In another example, the openings 10d may be provided
to mutually different surfaces of the housing 10.
[0129] The closed covers 11, 16, and 22 may be fastened by any method other than
10 the method in the above-described examples, provided that the method can hold and
press the sealing members 14, 19, and 25 between the covers 11, 16, and 22 and the
housing 10, with the covers 11, 16, and 22 fastened, respectively.
[0130] The engaging members 11b, 16b, and 22b may have any shape other than
that in the above-described examples provided that the engaging members 11b, 16b, and
15 22b can engage with the support members 12, 17, and 23, respectively. The engaging
members 11b, 16b, and 22b may be fixed on the covers 11, 16, and 22, respectively, by
any method other than the fastening with the fastening members. For example, the
engaging members 11b, 16b, and 22b may be fixed on the covers 11, 16, and 22,
respectively, with an adhesive or by welding. Alternatively, the engaging members 11b,
20 16b, and 22b may be formed integrally with the covers 11, 16, and 22, respectively.
[0131] The support members 12, 17, and 23 may have any shape other than that in
the above-described examples provided that the support members 12, 17, and 23 can
support the engaging members 11b, 16b, and 22b, respectively. For example, the
support members 12, 17, and 23 may be mounted on the upper surface of the housing 10
25 in the vertical direction, and may have a shape that supports the engaging members 11b,
16b, and 22b that are mounted on the covers 11, 16, and 22, respectively, disposed over
the openings 10a, 10c, and 10d provided to the side surface of the housing 10.
40
Alternatively, the support members 12, 17, and 23 may have structures for respectively
supporting the covers 11, 16, and 22 such that the covers 11, 16, and 22 can be opened
and closed about a rotational axis extending in the vertical direction.
[0132] The numbers and positions of the support members 12, 17, and 23 may be
5 arbitrarily defined in view of the parameters, such as sizes, materials, and weights of the
covers 11, 16, and 22.
The support members 12, 17, and 23 may be fixed on the housing 10 by any
method other than the fastening with the fastening members. For example, the support
members 12, 17, and 23 may be fixed on the housing 10 with an adhesive or by welding.
10 [0133] The sealing member 14 may have any shape other than that in the
above-described examples, provided that the sealing member 14 can surround the
opening 10a such that the sealing member 14 is held between the cover 11 and the
housing 10 when the cover 11 is closed. In one example, the sealing member 14 may
lack the groove 14a and be bonded to the circumference of the opening 10a of the
15 housing 10 with an adhesive. In another example, the sealing member 14 may be fixed
on the cover 11. The same holds true for the sealing members 19 and 25.
[0134] The first vibration sensors 13, 18, and 24 and the second vibration sensor 20
may be fed with electric power from the electronic equipment 71 accommodated in the
housing 10 as in Embodiments 1 to 4, or may include internal power sources.
20 [0135] It is sufficient that each of the in-vehicle devices 1 to 4 includes at least one
of the first vibration sensors 13, 18, and 24, and any number of first vibration sensors 13,
18, and 24 may be provided, other than those in the above-described examples. The
above-mentioned positions of the first vibration sensors 13, 18, and 24 are mere examples.
For example, the cover 11 may be provided with multiple first vibration sensors 13. In
25 this case, the degradation determiner 31 may calculate oscillation frequencies from the
respective values measured by the first vibration sensors 13 and determine whether each
of the oscillation frequencies falls within the frequency range. Alternatively, the
41
degradation determiner 31 may calculate the average of the respective oscillation
frequencies and determine whether the average of the oscillation frequencies falls within
the frequency range.
[0136] Each of the first vibration sensors 13, 18, and 24 is not necessarily a
5 vibration sensor for measuring an acceleration and may also be a vibration sensor for
measuring a speed or displacement. The first vibration sensors 13, 18, and 24 may be
provided to the housing 10 to measure mechanical vibration of the covers 11, 16, and 22,
respectively. In this case, the first vibration sensors 13, 18, and 24 may be a
non-contact-type vibration sensor.
10 [0137] The above-described number and position of the second vibration sensor 20
is a mere example. For example, multiple inner surfaces of the housing 10 may each
have a second vibration sensor 20. In this case, the degradation determiner 33 may
determine whether any degradation occurs in the sealing member 14, on the basis of the
difference between the average of the respective maximum values of the values measured
15 by the second vibration sensors 20 and the maximum value of the values measured by the
first vibration sensor 13.
[0138] The second vibration sensor 20 is not necessarily a vibration sensor for
measuring an acceleration and may be a vibration sensor for measuring a speed or
displacement. The second vibration sensor 20 may be disposed at a position distant
20 from the inner surface of the housing 10. In this case, the second vibration sensor 20
may be a non-contact-type vibration sensor.
[0139] The restricting members 22d may have any shape other than that in the
above-described example, provided that the restricting members 22d can restrict
movement of the covers 22 while the covers 22 are closed.
25 [0140] The degradation determiners 31, 32, 33, and 34 may be achieved as one of
the functions of the electronic equipment 71. For example, the degradation determiners
31, 32, 33, and 34 may be equipped as one of the functions of the power conversion
42
apparatus, which is the electronic equipment 71.
Alternatively, the degradation determiners 31, 32, 33, and 34 may be provided
outside the housing 10. In one example, the degradation determiners 31, 32, 33, and 34
may be achieved as one of the functions of the train information management system 91.
5 In another example, the degradation determiners 31, 32, 33, and 34 are not necessarily
installed in the vehicle including the in-vehicle devices 1 to 4. In this case, the
degradation determiners 31, 32, 33, and 34 may acquire measured values from the first
vibration sensors 13, 18, and 24 and the second vibration sensor 20 via any network.
[0141] The degradation determiners 31, 32, 33, and 34 may cause determination
10 results to be stored into a memory, which is not illustrated, without transmitting the
determination results to the train information management system 91. In this case, a
maintenance terminal may access the memory and read the determination results during
maintenance.
[0142] The above-described processes executed by the degradation determiners 31,
15 32, 33, and 34 are mere examples.
In one example, the degradation determiners 31, 32, 33, and 34 may repeat the
degradation determining process without acquiring a driving instruction or environmental
information. Specifically, the degradation determiner 31 may skip Steps S11 and S12 in
FIG. 7 and execute Step S13 and the following steps. Also, the degradation determiner
20 32 may skip Steps S21 to S23 in FIG. 12 and execute Step S24 and the following steps.
Also, the degradation determiner 33 may skip Steps S31 and S32 in FIG. 16 and execute
Step S33 and the following steps. Also, the degradation determiner 34 may skip Steps
S41 and S42 in FIG. 20 and execute Step S43 and the following steps.
[0143] Steps S21 and S22 in FIG. 12 may be executed in parallel, or Step S22 may
25 be followed by Step S21.
[0144] In another example, the degradation determiner 31 may determine that any
degradation occurs in the sealing member 14, when the number of times that the
43
oscillation frequency deviates from the frequency range is larger than a predetermined
number of times within a predetermined determination period. The determination
period can be any period that is long enough not to mistake a sudden variation in the
mechanical vibration of the cover 11 as occurrence of degradation in the sealing member
5 14.
In another example, the degradation determiner 32 may determine whether any
degradation occurs in the sealing member 19 only when the vehicle is standing still. In
this case, the degradation determiner 32 does not have to acquire a driving instruction
from the train information management system 91.
10 [0145] The degradation determining processes executed by the degradation
determiners 31, 32, 33, and 34 may be arbitrarily combined with each other.
In one example, the degradation determiner 31 may acquire a driving instruction
and pieces of environmental information, and execute Step S13 in FIG. 7 when the
driving instruction does not include the power running instruction or the braking
15 instruction and when the environmental conditions defined for the respective pieces of
environmental information are satisfied.
[0146] In another example, the degradation determiner 32 may acquire a driving
instruction, the speed of the vehicle, and pieces of environmental information, and
execute Step S24 in FIG. 12 when the driving instruction does not include the power
20 running instruction or the braking instruction or when the vehicle is standing still and
when the environmental conditions defined for the respective pieces of environmental
information are satisfied.
[0147] In another example, the degradation determiner 33 may acquire a driving
instruction and pieces of environmental information, and execute Step S33 in FIG. 16
25 when the driving instruction does not include the power running instruction or the
braking instruction and when the environmental conditions defined for the respective
pieces of environmental information are satisfied.
44
[0148] In another example, the degradation determiner 34 may acquire a driving
instruction and pieces of environmental information, and execute Step S43 in FIG. 20
when the driving instruction does not include the power running instruction or the
braking instruction and when the environmental conditions defined for the respective
5 pieces of environmental information are satisfied.
[0149] In another example, the degradation determiners 32, 33, and 34 may execute
the degradation determining process on the basis of oscillation frequencies, like the
degradation determiner 31. For example, the degradation determiner 32 may determine
whether the oscillation frequency calculated from the value measured by the first
10 vibration sensor 18 falls within a frequency range.
[0150] For example, the degradation determiner 33 may determine whether the
difference between the oscillation frequency calculated from the value measured by the
first vibration sensor 13 and the oscillation frequency calculated from the value measured
by the second vibration sensor 20 falls within a difference range. In this case, the
15 difference range may be defined on the basis of possible values of the oscillation
frequency of the mechanical vibration of the cover 11 and possible values of the
oscillation frequency of the mechanical vibration of the housing 10.
[0151] For example, the degradation determiner 34 may determine whether the
average of the respective maximum values of the values measured by the first vibration
20 sensors 24 within a unit time falls within an average range. In this case, the average
range may be defined on the basis of possible values of the maximum amplitude of the
mechanical vibration of the covers 22.
[0152] The sealing members 25 having different shapes or made of different
materials are expected to degrade at different rates. In this case, the degradation
25 determiner 34 may determine whether any degradation occurs in the sealing members 25
on the basis of the dispersion of the oscillation frequencies calculated from the respective
values measured by the first vibration sensors 24.
45
[0153] Specifically, the degradation determiner 34 may determine whether the
difference between the oscillation frequency calculated from the value measured by any
one first vibration sensor 24 and the average of the oscillation frequencies calculated from
the values measured by another first vibration sensors 24 falls within a difference range.
5 When the difference between the oscillation frequency calculated from the value
measured by the one first vibration sensors 24 and the average of the oscillation
frequencies calculated from the values measured by another first vibration sensors 24
does not fall within the difference range, this situation can be deemed that any
degradation occurs in the sealing member 25 disposed around the opening 10d covered
10 with the cover 22, which is the measurement target of the one of the first vibration
sensors 24.
[0154] The degradation determiner 32 may determine whether the vehicle is
standing still on the basis of information other than the speed of the vehicle. In one
example, the degradation determiner 32 may acquire a signal for controlling the opening
15 or closing of doors from the train information management system 91, and execute the
degradation determining process when the opening-closing control signal indicates that
the doors are open. In another example, the degradation determiner 32 may acquire a
pulse signal from a pulse generator mounted on an axle, and execute the degradation
determining process when the rotational frequency calculated from the pulse signal can
20 be deemed as 0.
[0155] The degradation determiner 31 may determine whether any degradation
occurs in the sealing member 14 using a frequency range that varies depending on
environmental information. Specifically, the vehicle is more likely to slide and may
cause big vibration of the cover 11 in rainy weather in comparison to the vehicle in sunny
25 weather. The degradation determiner 31 may therefore use a broader frequency range in
rainy weather than that in sunny weather. Also, the amplitude threshold, the difference
range, and the average range may vary depending on environmental information.
46
[0156] The foregoing describes some example embodiments for explanatory
purposes. Although the foregoing discussion has presented specific embodiments,
persons skilled in the art will recognize that changes may be made in form and detail
without departing from the broader spirit and scope of the invention. Accordingly, the
5 specification and drawings are to be regarded in an illustrative rather than a restrictive
sense. This detailed description, therefore, is not to be taken in a limiting sense, and the
scope of the invention is defined only by the included claims, along with the full range of
equivalents to which such claims are entitled.
Reference Signs List
10 [0157] 1, 2, 3, 4 In-vehicle device
10 Housing
10a, 10c, 10d Opening
10b Edge
11, 16, 22 Cover
15 11a, 16a, 22a Outer surface
11b, 16b, 22b Engaging member
11c, 16c, 22c Inner surface
12, 17, 23 Support member
13, 18, 24 First vibration sensor
20 14, 19, 25 Sealing member
14a Groove
15, 21 Cable
20 Second vibration sensor
22d Restricting member
25 31, 32, 33, 34 Degradation determiner
41 Sampling circuit
42 FFT circuit
47
43, 49, 51 Determination circuit
44 Communication circuit
45 Control circuit
46 Comparison circuit
5 47 Counter circuit
48 Difference circuit
50 Average circuit
60 Bus
61 Processor
10 62 Memory
63 Interface
71 Electronic equipment
91 Train information management system
AX1, AX2 Rotational axis
48
WE CLAIM:
1. An in-vehicle device installable in a vehicle, the device comprising:
a housing having an opening;
a cover that is disposed over the opening and openable and closable;
5 a sealing member disposed around the opening such that the sealing member is
held between the housing and the cover when the cover is closed;
at least one first vibration sensor to measure mechanical vibration of the cover; and
a degradation determiner to determine, based on the mechanical vibration
measured by the at least one first vibration sensor while the cover is closed, whether any
10 degradation occurs in the sealing member.
2. The in-vehicle device according to claim 1, wherein, in a case where the
vehicle is coasting, the degradation determiner determines whether any degradation
occurs in the sealing member.
15
3. The in-vehicle device according to claim 2, wherein the degradation
determiner acquires a driving instruction for designating an acceleration of the vehicle
and determines, based on the driving instruction, whether the vehicle is coasting.
20 4. The in-vehicle device according to any one of claims 1 to 3, wherein, in a
case where the vehicle is standing still, the degradation determiner determines whether
any degradation occurs in the sealing member.
5. The in-vehicle device according to any one of claims 1 to 4, wherein the
25 degradation determiner determines, based on an oscillation frequency of the mechanical
vibration measured by the at least one first vibration sensor, whether any degradation
occurs in the sealing member.
49
6. The in-vehicle device according to any one of claims 1 to 4, wherein the
degradation determiner determines, based on an amplitude of the mechanical vibration
measured by the at least one first vibration sensor, whether any degradation occurs in the
5 sealing member.
7. The in-vehicle device according to any one of claims 1 to 4, wherein
the at least one first vibration sensor comprises a plurality of the first vibration
sensors, and
10 the degradation determiner determines, based on an average calculated from
oscillation frequencies of mechanical vibration measured by the plurality of respective
first vibration sensors, whether any degradation occurs in the sealing member.
8. The in-vehicle device according to any one of claims 1 to 4, wherein
15 the at least one first vibration sensor comprises a plurality of the first vibration
sensors, and
the degradation determiner determines, based on an average calculated from
maximum amplitudes of mechanical vibration measured by the plurality of respective
first vibration sensors, whether any degradation occurs in the sealing member.
20
9. The in-vehicle device according to any one of claims 1 to 8, wherein the at
least one first vibration sensor is mounted on an inner surface of the cover.
10. The in-vehicle device according to any one of claims 1 to 9, further
25 comprising a support member to support the cover, wherein
the at least one first vibration sensor is disposed at a position at least a first distance
away from the support member when the cover is closed.
50
11. The in-vehicle device according to any one of claims 1 to 10, wherein the at
least one first vibration sensor operates upon reception of electric power fed from
electronic equipment accommodated in the housing and measures the mechanical
5 vibration of the cover.
12. The in-vehicle device according to any one of claims 1 to 11, further
comprising a restricting member to restrict movement of the cover while the cover is
closed, wherein
10 the at least one first vibration sensor is disposed at a position at least a second
distance away from the restricting member when the cover is closed.
13. The in-vehicle device according to any one of claims 1 to 4, further
comprising at least one second vibration sensor to measure mechanical vibration of the
15 housing, wherein
the degradation determiner determines whether any degradation occurs in the
sealing member, based on the mechanical vibration of the cover measured by the at least
one first vibration sensor while the cover is closed and the mechanical vibration of the
housing measured by the at least one second vibration sensor while the cover is closed.
20
14. The in-vehicle device according to claim 13, wherein the degradation
determiner determines whether any degradation occurs in the sealing member, based on a
difference between a maximum amplitude of the mechanical vibration of the cover
measured by the at least one first vibration sensor and a maximum amplitude of the
25 mechanical vibration of the housing measured by the at least one second vibration sensor.
15. The in-vehicle device according to claim 13 or 14, wherein the at least one
51
second vibration sensor is mounted on an inner surface of the housing.
16. The in-vehicle device according to any one of claims 13 to 15, wherein the at
least one second vibration sensor operates upon reception of electric power fed from
5 electronic equipment accommodated in the housing and measures the mechanical
vibration of the housing.
17. The in-vehicle device according to any one of claims 1 to 16, wherein the
degradation determiner acquires environmental information including at least one of a
10 place where the vehicle is running, a temperature outside the housing, or weather, and
determines whether any degradation occurs in the sealing member when an
environmental condition defined for each piece of environmental information is satisfied.
18. A degradation determining method, comprising:
15 determining, based on mechanical vibration of a cover, whether any degradation
occurs in a sealing member, the cover being disposed over an opening of a housing
included in an in-vehicle device installed in a vehicle, the sealing member being disposed
around the opening such that the sealing member is held between the housing and the
cover when the cover is closed.