JP7671259B2 - On-board communication device and self-diagnosis method for on-board communication device - Google Patents

Description

The present invention relates to an on-board communication device and a self-diagnosis method for the on-board communication device.

The on-board transponder equipment on the vehicle transmits and receives telegram information to and from ground communication equipment installed on the track. Data such as the vehicle's speed limit and position information obtained from the ground communication equipment is used for important vehicle operation control, such as vehicle speed control. There are two types of ground communication equipment: powered ground communication equipment that receives power from ground equipment, and unpowered ground communication equipment that receives power from power waves from the on-board transponder equipment and is activated. Both types of ground communication equipment transmit telegram information at a frequency different from the power waves to the on-board communication equipment. Here, as mentioned above, communication between the on-board communication equipment and the ground communication equipment can affect the safety of vehicle operation, so the on-board communication equipment is required to communicate reliably with the ground communication equipment.

In particular, to start up the non-powered ground communication device and reliably communicate with it, it is essential to transmit stable power from the on-board transponder device to the ground communication device. Therefore, it is important to perform self-diagnosis of the power wave transmission circuit and reliably detect any faults.

JP 2015-222907 A

Self-diagnosis of the power wave is performed by a monitor function that monitors the power wave transmission level. The monitor function measures the power wave transmission output and constantly checks whether it is outputting a level that can activate the ground coil. In addition, self-diagnosis of this monitor function itself is also necessary, and the power wave output level is deliberately lowered to check that the monitor function detects the drop in power wave level and detects a fault. This self-diagnosis of the monitor function cannot be performed while the train is moving, as it changes the power wave transmission level, and is instead performed when the on-board transponder device is activated.

If there is a metal bridge plate installed in a ground coil or a depot pit near the on-board transponder equipment, the impedance will increase due to coupling with the ground coil or the effect of eddy currents generated in the bridge plate, which will shift the resonance frequency of the on-board equipment. This makes it difficult for the power wave current to flow, lowering the monitor value and causing the on-board equipment to be judged as faulty even though there is nothing wrong with it.

Patent Document 1 shows a method in which, when an on-board device is activated near a ground coil, the ground coil is activated by outputting a power wave at the same level as when the train is moving, causing the ground coil to transmit an information wave, and when the information wave from the ground coil is detected, the threshold value of the power wave monitor value is lowered below normal to perform diagnosis.

However, according to the above method described in Patent Document 1, it is necessary to set in advance the threshold for the decrease in the power wave monitor value when a ground coil is detected, and if the installation height of the on-board coil is different, the degree of influence of the ground coil changes, so it is necessary to set the threshold value according to the installation height. Furthermore, because a gangway does not transmit information waves, it is not possible to detect that it is near a gangway, and there is an issue that the threshold for the power wave monitor value cannot be changed.

The present invention has been made in consideration of the above, and one of its objectives is to enable normal self-diagnosis of the power wave monitor in an on-board communication device, even if a ground coil or gangway is present near the on-board coil.

In order to solve the above problems, one aspect of the present invention is an on-board communication device mounted on a vehicle traveling on a track, comprising: an on-board coil that transmits power waves to a ground coil installed on the track and receives information waves from the ground coil; an information wave receiving unit that transmits data obtained by demodulating the information waves received by the on-board coil to a control unit; a power wave transmitting circuit that transmits power waves to the on-board coil in accordance with a power wave transmission instruction output from the control unit; a power wave monitor that outputs a power wave monitor signal based on the power wave level of the power wave transmitting circuit; and a control unit that performs a health diagnosis of the power wave monitor based on the power wave monitor signal, and is characterized in that the device is equipped with a simulated load having an impedance equivalent to the on-board coil, and a load switching circuit that switches the connection destination of the power wave transmitting circuit between the on-board coil and the simulated load.

According to the present invention, for example, in an on-board communication device, normal self-diagnosis of the power wave monitor is possible even if a ground coil or a gangway is present near the on-board coil.

FIG. 1 is a diagram illustrating an example of the configuration of an on-board communication device according to a first embodiment. FIG. 2 is a diagram showing in detail an example of the configuration of an on-board communication device according to the first embodiment. FIG. 2 is a diagram showing a configuration example of a load switching circuit of the on-board communication device according to the first embodiment. FIG. 13 is a diagram for explaining an image of power wave output characteristics. A diagram to explain the traveling distance when the disablement of the output of the power wave fault detection signal when the on-board device is activated directly above the gangway is released. FIG. 13 is a diagram showing an example of the configuration of an on-board communication device according to a second embodiment.

Below, an embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to this embodiment. In the drawings, the same parts are denoted by the same reference numerals. In addition, sub-numbers are added to the same reference numerals to distinguish between multiple identical components. In addition, in the description of the embodiments described later, differences from the previously described embodiments will be mainly described, and duplicated description will be omitted.

[Embodiment 1]
1 is a diagram illustrating a schematic configuration example of an on-board communication device 1 according to the first embodiment. The on-board communication device 1 is mounted on a vehicle traveling on a track such as a railway. The on-board communication device 1 generates a power wave in a power wave transmission circuit 10 in response to a power wave transmission command received from a control unit 2, and transmits the power wave to a ground coil 3 installed on the track via a load switching circuit 12 and an on-board coil 13. At this time, an output control unit 11 monitors the output of the power wave transmission circuit 10, and when the output level falls outside a specified range, determines that the power wave transmission circuit 10 or the on-board coil 13, which is a load, has failed, and transmits a failure detection signal to the control unit 2.

The on-board communication device 1 also has an on-board coil 13 and a dummy load 14 having an impedance equivalent to that of the on-board coil 13 as output destinations of the power wave transmission circuit 10. The power wave transmission circuit 10 is equipped with a load switching circuit 12 that connects to either the on-board coil 13 or the dummy load 14. The load switching circuit 12 connects the on-board coil 13 or the dummy load 14 to the power wave transmission circuit in accordance with a load switching signal 118.

Figure 2 is a diagram showing in detail an example of the configuration of the on-board communication device 1 according to the first embodiment. The power wave transmission circuit 10 has an oscillator 101, a preamplifier 102 that amplifies the output of the oscillator 101, a variable attenuator 103 that attenuates the output of the preamplifier 102 to adjust the level, an output stage amplifier 104 that amplifies the power wave whose level has been adjusted by the variable attenuator 103, and a low pass filter (LPF) 105 that removes distortion of the output waveform of the output stage amplifier 104.

The output control unit 11 has a power wave control unit 111 that controls the frequency setting and output ON/OFF of the power wave in response to a power wave transmission command received from the control unit 2, a power wave monitor 113a that measures the output current of the power wave transmission circuit 10 and outputs a power wave monitor signal 117a of the power wave transmission circuit 10 according to the power wave level based on the output current, an A/D converter 112a that converts the output of the power wave monitor 113a into a digital signal, and a D/A converter 114 that converts the power wave output level control signal 116 output from the power wave control unit 111 to an analog signal to control the variable attenuator 103. The output control unit 11 transmits a failure detection signal 115 to the control unit 2 when the power wave monitor signal 117a falls outside a specified range.

The information wave receiving unit 15 has a bandpass filter 151 that removes unnecessary frequencies from the information wave received from the on-board coil 13, a preamplifier 152 that amplifies the output of the bandpass filter 151, an A/D converter 112 that converts the output of the preamplifier 152 into a digital signal, and an information wave control unit 153 that demodulates the converted digital signal and transmits the message received from the ground coil to the control unit 2.

The on-board communication device 1 also includes a transformer 16 for isolation and balanced-to-unbalanced conversion between the power wave transmission circuit 10 and the on-board terminal 13, and a load switching circuit 12 for connecting either the on-board terminal 13 or the dummy load 14 to the power wave transmission circuit 10.

The electric power wave control unit 111 controls the load switching circuit 12 so that the load of the electric power wave transmission circuit 10 becomes the dummy load 14 immediately after the on-board communication device 1 is started. Furthermore, the electric power wave control unit 111 changes the electric power wave output level control signal 116 for self-diagnosis of the electric power wave monitor 113a, and confirms that when the electric power wave output level control signal 116 causes the output level of the electric power wave transmission circuit 10 to be outside the specified range, the electric power wave monitor signal 117a also becomes outside the specified range. After the self-diagnosis of the electric power wave monitor 113a is completed, the electric power wave control unit 111 switches the load switching circuit 12 so that the load of the electric power wave transmission circuit 10 becomes the on-board coil 13, and transitions to normal operation.

Figure 3 is a diagram showing an example of the configuration of the load switching circuit 12 of the on-board communication device 1 according to the first embodiment. The load switching circuit 12 connects either the on-board coil 13 or the dummy load 14 as the load of the power wave transmission circuit 10 in accordance with the load switching signal 118. The load switching circuit 12 connects the load to the on-board coil 13 during normal operation, and to the dummy load 14 during self-diagnosis of the power wave monitor 113a.

Figure 4 is a diagram for explaining the image of the power wave output characteristic, with the horizontal axis representing the strength of the power wave output level control signal 116 and the vertical axis representing the strength of the power wave monitor signal 117. When the power wave transmission circuit 10, the output control section 11, and the load of the power wave transmission circuit 10 are normal, i.e., when there is no ground coil 3 or crossing plate 4 near the on-board coil 13, or when a dummy load 14 is connected, the power wave output characteristic 51 shown in Figure 4 is obtained. The crossing plate 4 is an example of an obstruction that may be present in a certain vicinity of the on-board coil 13 and that interferes with the normal fault detection of the power wave transmission circuit 10 by the power wave monitor 113a.

To check whether a drop in the power wave level is detected as a fault, a test is performed by actually lowering the power wave level. This can be confirmed by checking that the power wave monitor signal 117a is less than the power wave lower limit threshold 55 when the power wave output level control signal 116 is set to a predetermined intensity 54. Also, if the monitor value 56 of the power wave monitor signal 117a is equal to or greater than the power wave lower limit threshold 55 when the power wave output level control signal 116 is set to the power wave output level setting value 53 during normal operation, it can be confirmed that the power wave output characteristic 51 is normal. The health check of these power wave monitors 113a needs to be performed before the device is operated immediately after the device is started up, because the test is performed by changing the power wave level setting value.

When the ground coil 3 or the crossing plate 4 is near the on-board coil 13, the power wave output characteristic 52 appears, which does not match the power wave output characteristic 51 in normal operation, and the soundness of the power wave monitor 113a cannot be confirmed. In other words, it is confirmed that the power wave output characteristic 52, which is based on the level of the power wave monitor signal 117a when the power wave output level control signal 116 is set to a predetermined intensity 54 and the level of the power wave monitor signal 117a when the power wave output level control signal 116 is set to the power wave output level setting value 53 in normal operation, differs from the power wave output characteristic 51 in normal operation.

Therefore, the power wave transmission circuit 10 is connected to a dummy load 14 to check the soundness of the power wave monitor signal 117a, and after the soundness check is completed, the load is switched to the on-board coil 13. If the on-board coil 13 is located directly above the ground coil 3 or the crossing plate 4, switching the load of the power wave transmission circuit 10 to the on-board coil 13 may output a fault detection signal 115, so this is avoided by the following method.

When the on-board coil 13 is directly above the ground coil 3, the power waves transmitted by the on-board coil 13 activate the ground coil 3 and transmit an information wave. When the information wave receiving unit 15 detects the information wave, it transmits information wave detection information and an information wave message to the control unit 2. When the control unit 2 receives the information wave detection information, it disables the output of the fault detection signal 115 to prevent a fault determination. When the vehicle starts moving, it leaves the ground coil 3 and cannot receive information waves, so the information wave detection signal stops, and the control unit 2 enables the output of the disabled fault detection signal 115, thereby resuming fault diagnosis of the power wave transmission circuit 10 based on the power waves output by the power wave transmission circuit 10.

When the on-board unit 13 is directly above the gangway 4, the speed information 21 input to the control unit 2 is used to disable the output of the fault detection signal 115 when the vehicle is stopped, preventing a fault determination. When the vehicle starts to move and detects that it has traveled a specified distance, the control unit 2 enables the output of the fault detection signal 115 that was disabled, thereby resuming fault diagnosis of the power wave transmission circuit 10 based on the power wave output by the power wave transmission circuit 10.

Figure 5 is a diagram for explaining the travel distance when disabling the output of the power wave fault detection signal when the on-board device is activated directly above the gangway is released. Figure 5 shows the relative positional relationship of the on-board coils 13a, 13b, and the gangway 4 in the vehicle travel direction (left-right direction on the page) and vertical direction (up-down direction on the page).

The control unit 2 of the on-board communication device 1 disables the output of the failure detection signal 115 when the on-board terminal 13 moves from the position of the on-board terminal 13a near the crossing board 4 to the position of the on-board terminal 13b. Because the control unit 2 cannot detect the positional relationship between the on-board terminal 13 and the crossing board 4, it is sufficient to use the movement distance from the position of the on-board terminal 13a, which is affected by the crossing board 4, to the position of the on-board terminal 13b to cancel the failure detection signal 115.

Specifically, if the length 113 of the on-board coil 13 in the vehicle travel direction is L1 and the length 41 of the crossing plate 4 in the vehicle travel direction is L2, then the distance 134 at which the disablement of the output of the power wave fault detection signal is released is expressed as L1 + L2. Therefore, if the travel distance calculated from the speed information 21 after the output of the fault detection signal 115 is disabled exceeds the previously registered L1 + L2, the control unit 2 releases the disablement of the output of the fault detection signal 115 (i.e., enables the output of the fault detection signal 115), thereby making it possible to prevent erroneous detection of a fault and transition to operation.

[Embodiment 2]
Fig. 6 is a diagram showing an example of the configuration of an on-board communication device 1B according to embodiment 2. The configuration of the on-board communication device 1B is the same as that of the on-board communication device 1 (Fig. 2) according to embodiment 1, except that it has an output control unit 11B instead of the output control unit 11. The output control unit 11B is obtained by adding a power wave monitor 113b for detecting a power wave level between the load switching circuit 12 and the dummy load 14, an A/D converter 112b, and a power wave monitor signal 117b.

When the load switching circuit 12 is normal and the dummy load 14 is selected as the load for the power wave transmission circuit 10, the output of the power wave transmission circuit 10 is entirely supplied to the dummy load 14, so the power wave monitor signal 117a and the power wave monitor signal 117b match. Also, when the on-board coil 13 is selected as the load for the power wave transmission circuit 10, the output of the power wave transmission circuit 10 is not supplied to the dummy load 14, so the power wave monitor signal 117b is zero. In these cases, the control unit 2 diagnoses that the load switching circuit 12 is normal.

In addition, if the contacts of the load switching circuit 12 are stuck and both the on-board terminal 13 and the dummy load 14 are connected as loads to the power wave transmission circuit 10, the power wave monitor signal 117b will not match the power wave monitor signal 117a and will not become zero, which can be detected as an abnormality. At this time, the control unit 2 diagnoses the load switching circuit 12 as being faulty (stuck in connection to both the on-board terminal 13 and the dummy load 14).

Similarly, if all of the contacts of the load switching circuit 12 become loose, the power wave monitor signal 117a does not reach the specified level, and this can be detected. At this time, the control unit 2 diagnoses that the load switching circuit 12 is broken (loose contact at all of the contacts of the on-board unit 13 and the dummy load 14).

According to the above-described embodiment, when the vehicle is started, such as when it leaves the depot, the load of the power wave transmission circuit 10 is connected to the dummy load 14 when the on-board communication devices 1, 1B are started. This prevents the load impedance of the power wave transmission circuit 10 from fluctuating even if the ground coil 3 or the crossing plate 4 is present near the on-board coil 13, and allows the self-diagnosis of the power wave monitor 113a to be performed under stable conditions. This makes it possible to prevent erroneous detection of a failure due to the influence of the ground coil 3 or the crossing plate 4, even when the on-board communication devices 1, 1B are functioning normally.

The variable attenuator 103, the power wave monitors 113a and 113b, the A/D converters 112a and 112b, and the D/A converter 114 are one of the means for realizing the above-mentioned embodiment, and the above-mentioned embodiment does not limit these configurations. For example, the power wave level may be controlled using a variable amplifier instead of the variable attenuator 103, or the power wave voltage may be divided and input to the D/A converter 114 without going through the power wave monitor 113a.

The preamplifier 102, output stage amplifier 104, low-pass filter 105, and transformer 16 are not essential components of the above-described embodiment, and may be deleted if not required. In addition to those shown in FIG. 2 and FIG. 6, a signal conversion circuit, a filter, etc. may be added as necessary.

Furthermore, the control of the load switching circuit 12 may be performed by the control unit 2 rather than by the power wave control unit 111.

The disclosed technology is not limited to the above-described embodiment, and various changes and modifications are possible by those skilled in the art within the scope of the technical ideas disclosed in this application, and various modified examples are included. Furthermore, the above-described embodiment is an example given to clearly explain the disclosed technology, and is not necessarily limited to those having all of the configurations described. Furthermore, it is possible to add or replace part of the configuration of the above-described embodiment with the configuration of another embodiment or modified example, or to delete part of the configuration of the above-described embodiment.

1, 1B: on-board communication device, 2: control unit, 3: ground coil, 4: gangway, 10: power wave transmitting circuit, 11: output control unit, 12: load switching circuit, 13, 13a, 13b: on-board coil, 14: dummy load, 15: information wave receiving unit.

Claims (8)

An on-board communication device mounted on a vehicle traveling on a railroad track,
an on-board coil that transmits power waves to a ground coil installed on the track and receives information waves from the ground coil;
an information wave receiving unit that transmits data obtained by demodulating the information wave received by the on-board unit to a control unit;
a power wave transmission circuit for transmitting a power wave to the on-board coil in accordance with a power wave transmission instruction output from the control unit;
a power wave monitor that outputs a power wave monitor signal based on a power wave level of the power wave transmission circuit;
a control unit that performs a health diagnosis of the power wave monitor based on the power wave monitor signal,
A simulated load having an impedance equivalent to the on-board coil;
a load switching circuit that switches a connection destination of the power wave transmission circuit between the on-board coil and the dummy load. The on-board communication device according to claim 1,
a second power wave monitor that outputs a second power wave monitor signal based on a power wave level between the load switching circuit and the dummy load;
The control unit is
An on-board communication device characterized in that a fault in the load switching circuit is detected based on the power wave monitor signal and the second power wave monitor signal. The on-board communication device according to claim 2,
The control unit is
When the electric power wave monitor signal and the second electric power wave monitor signal match, the load switching circuit is diagnosed as normal;
When the power wave monitor signal and the second power wave monitor signal do not match and do not become zero, the load switching circuit diagnoses a fault in connection with both the on-board unit and the dummy load;
An on-board communication device characterized in that, when the power wave monitor signal and the second power wave monitor signal do not reach specified levels, the load switching circuit diagnoses a fault due to poor contact in the contacts of both the on-board device and the dummy load. The on-board communication device according to any one of claims 1 to 3,
The load switching circuit includes:
When the on-board communication device is started, the power wave transmission circuit is connected to the dummy load;
An on-board communication device characterized in that, after the health diagnosis is completed, the connection destination of the power wave transmission circuit is switched from the dummy load to the on-board terminal. The on-board communication device according to claim 4,
The control unit is
An on-board communication device characterized in that the power wave monitor is diagnosed as normal when a power wave output characteristic based on a first value where the level of the power wave monitor signal detected by the power wave monitor when the power wave level of the power wave transmission circuit is set to a first predetermined intensity is less than a threshold value, and a second value where the level of the power wave monitor signal detected by the power wave monitor when the power wave level is set to a second predetermined intensity greater than the first predetermined intensity is equal to or greater than the threshold value, matches a power wave output characteristic under normal conditions. The on-board communication device according to claim 4 or 5,
The control unit is
after the health diagnosis is completed, when a fault is detected in the electric power wave transmission circuit when the connection destination of the electric power wave transmission circuit is switched from the dummy load to the on-board unit, output of a fault detection signal indicating a fault in the electric power wave transmission circuit is disabled;
An on-board communication device characterized in that after detecting that the vehicle has traveled a predetermined distance based on speed information input to the control unit, output of the failure detection signal is enabled. The on-board communication device according to claim 6,
An on-board communication device characterized in that the specified distance is determined based on the sum of the lengths in the direction of travel of the vehicle of the on-board unit and an obstacle that may be present in a specified vicinity of the on-board unit and that may prevent the power wave monitor from properly detecting a fault in the power wave transmitting circuit. A self-diagnosis method performed by an on-board communication device mounted on a vehicle traveling on a track, comprising:
The on-board communication device includes:
an on-board coil that transmits power waves to a ground coil installed on the track and receives information waves from the ground coil;
an information wave receiving unit that transmits data obtained by demodulating the information wave received by the on-board unit to a control unit;
a power wave transmission circuit for transmitting a power wave to the on-board coil in accordance with a power wave transmission instruction output from the control unit;
a power wave monitor that outputs a power wave monitor signal based on a power wave level of the power wave transmission circuit;
a control unit that performs a health diagnosis of the power wave monitor based on the power wave monitor signal;
A simulated load having an impedance equivalent to the on-board coil;
a load switching circuit for switching a connection destination of the power wave transmission circuit from the on-board coil to the dummy load,
The load switching circuit,
connecting the electric power wave transmitting circuit to the dummy load in order to perform a health diagnosis of the electric power wave monitor;
a connection destination of the power wave transmission circuit being switched from the dummy load to the on-board terminal after the health diagnosis is completed.

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