Patent Description:
The European train control system (ETCS) is a standard system that unifies different train control systems in Europe. This was originally used as a European standard, but has been developed into a global standard.

For example, a train control system that relates to ETCS is disclosed in <CIT>. Another train control system is known from <CIT>.

Detecting a position of a train is one of the most important issues in a train control process. To this end, various techniques have been developed and used to detect the position of the train.

For example, according to Patent Document <NUM> or <CIT>, there has been proposed a conventional train control system using a technique for detecting the position of the train.

Specifically, Patent Document <NUM> or Patent Document <NUM> discloses a configuration in which a vehicle on-board controller equipped in a train detects a position of a train through, e.g., an axle-mounted tachometer, a configuration in which a position of a train is detected through a global positioning system (GPS) receiver equipped in the train, and a configuration in which a position of a train is detected by reading radio frequency identification (RFID) tags installed along a train line.

Meanwhile, railway casualty accidents may occur when a train enters and passes a train line during maintenance operations on the train line or in a state where a passenger has fallen on the train line.

In this regard, according to <CIT>, there has been proposed a configuration in which railway safety-related accidents are prevented by scanning an area of a target train line.

However, the above described conventional techniques have the following problems.

First, the configuration for detecting the position of the train and the configuration for preventing the safety-related accidents are implemented in a completely different manner from each other. Thus, it is required to install the above configurations independently of each other.

Therefore, there arises, e.g., a cost increase problem since it is required to separately provide the configuration, disclosed in Patent Document <NUM> or Patent Document <NUM>, for detecting the position of the train and the configuration, disclosed in Patent Document <NUM>, for preventing the safety-related accidents.

Next, the configuration disclosed in Patent Document <NUM> or Patent Document <NUM> has a further problem that the maintenance cost becomes high and the reliability of the position detection is not guaranteed.

For example, in the configuration for detecting the position of the train using a GPS signal disclosed in Patent Document <NUM>, it is difficult to accurately detect the position of the train in a place such as a tunnel where the reception state of the GPS signal is poor. Further, in the configuration for detecting the position of the train using the tachometer, it is also difficult to accurately detect the position of the train due to maintenance failure or malfunction of the tachometer. Moreover, the tachometers or the receivers for receiving GPS signals are equipped in each of a large number of trains running on the train line to detect a position of each of the trains. In order to more reliably detect the position of each of the trains when using the GPS signals or the tachometers, it is necessary to periodically check the failure or the malfunction of the tachometers or the receivers for receiving the GPS signal equipped in each of the trains. Therefore, there also arises a significant cost increase for maintenance.

Further, for example, in the configurations disclosed in Patent Document <NUM> and Patent Document <NUM>, the position of the train is detected by detecting the RFID tags. Therefore, if there are defective tags among a large number of RFID tags installed along the train line, the position of the train cannot be detected at the places where the defective tags are disposed. This requires maintenance operations for the large number of RFID tags installed along the train line. In addition, it is also necessary to periodically check the failure or the malfunction of antennas in each of the trains running on the train line. Therefore, there also arises a significant cost increase for maintenance in the configuration for detecting the position of the train using the RFID tags.

In view of the above, an object of the present disclosure is to provide a train control system capable of efficiently and accurately detecting a position of a train by using a plurality of unattended ground sensors while minimizing a cost required for maintenance.

Further, another object of the present disclosure is to provide the train control system capable of detecting an obstacle or the presence of a human being around a train line by using the plurality of unattended ground sensors installed to detect the position of the train, thereby preventing railway casualty accidents.

The subject-matter of the claims is presented. In order to achieve the above object, in accordance with the present invention, there is provided a train control system including: a plurality of unattended ground sensors installed along a train line; and a control device configured to perform a third control mode for performing one mode selected, according to a predetermined criterion, from a first operation mode and a second operation mode, wherein in the first operation mode, a first control mode for detecting a position of a train based on data transmitted from the unattended ground sensors when the train travels on the train line is performed together with a second control mode for detecting safety information around the train line based on the data transmitted from the unattended ground sensors when vibrations around the train line is detected, and in the second operation mode, one of the first control mode and the second control mode is performed.

In the train control system according to the present invention, the control device may detect a current position of the train based on time (T1) at which a seismic wave generated by the train arrives at a first unattended ground sensor of the unattended ground sensors, time (T2) at which the seismic wave arrives at a second unattended ground sensor of the unattended ground sensors, a propagation velocity (v) of the seismic wave and a distance (D) between the first unattended ground sensor and the second unattended ground sensor.

Further, in the train control system according to the present invention, one or more of the unattended ground sensors may be connected to the train line through sensing lines, respectively.

Further, in the train control system according to the present invention, a distance between two adjacent unattended ground sensors of the unattended ground sensors installed along the train line may be set to be equal to or greater than <NUM>/<NUM> but equal to or less than <NUM>/<NUM> of a maximum sensing distance of each of the unattended ground sensors.

Further, in the train control system according to the present invention, the control device may be further configured to perform a fourth control mode for dynamically selecting the first unattended ground sensor and the second unattended ground sensor based on an operating state of each of the unattended ground sensors.

Further, in the train control system according to the present invention, the control device may be further configured to perform a fifth control mode for detecting a maintenance-required unattended ground sensor among the unattended ground sensors based on an operating state of each of the unattended ground sensors.

Further, in the train control system according to the present invention, the unattended ground sensors may communicate with one another through an ad-hoc wireless network.

Further, in the train control system according to the present invention, the train control system may further include at least one gateway configured to enable communication between the unattended ground sensors and the control device.

In accordance with the present invention, it is possible to provide the train control system capable of efficiently and accurately detecting the position of the train by using the plurality of unattended ground sensors while minimizing the cost required for maintenance.

Further, it is also possible to provide the train control system capable of detecting an obstacle or the presence of a human being around a train line by using the plurality of unattended ground sensors installed to detect the position of the train, thereby preventing railway casualty accidents.

Hereinafter, a train control system in accordance with the present invention will be described in detail with reference to the accompanying drawings.

<FIG> is a block diagram showing an exemplary configuration of a train control system according to the present invention.

Referring to <FIG>, the train control system includes a plurality of unattended ground sensors <NUM> and a control device <NUM>, and may further include a gateway <NUM>. However, it should be noted that the configurations of the train control system are not limited thereto, and the train control system may further include various configurations for the train control in addition to the unattended ground sensors <NUM>, the control device <NUM> and the gateway <NUM>.

In this embodiment, two or more unattended ground sensors <NUM> are provided. For example, an unattended ground sensor <NUM>-<NUM>, an unattended ground sensor <NUM>-<NUM>, and an unattended ground sensor <NUM>-<NUM> up to an unattended ground sensor <NUM>-n (where 'n' is a natural number of <NUM> or more) are provided.

It is preferable that all of the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> up to the unattended ground sensor <NUM>-n have the same configuration. However, it may be possible for some of the unattended ground sensors <NUM> to have a configuration different from that of the other unattended ground sensors <NUM>.

Each of the unattended ground sensors <NUM> is a sensor for detecting vibrations, e.g., seismic waves caused by an earthquake or the like. Each of the unattended ground sensors <NUM> is configured to detect the seismic waves and transmit the detected data to the control device <NUM> through a wired or wireless communication network. Specifically, each of the unattended ground sensors <NUM> may transmit data directly to the control device <NUM>, or some of the unattended ground sensors <NUM> may collect data from other unattended ground sensors <NUM> and transmit the collected data to the control device <NUM>. Alternatively, each of the unattended ground sensors <NUM> may transmit data to the control device <NUM> through the gateway <NUM>, which will be described later.

<FIG> shows an example of an arrangement of the unattended ground sensors <NUM> in the train control system according to the present invention.

Referring to <FIG>, four of the unattended ground sensors <NUM>, i.e., the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> are shown for the sake of explanation. However, the number of the unattended ground sensors <NUM> is not limited thereto.

The unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> are respectively installed along a train line <NUM>. The unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> may be installed to be spaced apart from the train line <NUM> by predetermined intervals.

Further, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> may be connected to the train line <NUM> through sensing lines <NUM>-<NUM> to <NUM>-<NUM>, respectively. In order to receive operating power and/or more accurately detect seismic waves by receiving the seismic waves transmitted through the train line <NUM> that is a constant medium, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> may be connected to the train line <NUM> through the sensing lines <NUM>-<NUM> to <NUM>-<NUM>, respectively.

A positional distance between two adjacent unattended ground sensors, e.g., the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> among the plurality of unattended ground sensors <NUM> is determined based on the maximum sensing distance of each of the unattended ground sensors <NUM>. The positional distance may be determined to be equal to or greater than <NUM>/<NUM> but equal to or less than <NUM>/<NUM> of the maximum sensing distance of each of the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM>.

For example, if the unattended ground sensors <NUM> are identical to each other and the maximum sensing distance of each of the unattended ground sensors <NUM> is <NUM> (meters), then the positional distance between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> is equal to or greater than <NUM> but equal to or less than <NUM>.

The maximum sensing distance of each of the unattended ground sensors <NUM> is determined based on the case where the seismic waves generated from a large-size object such as a train are to be detected.

In the case where two unattended ground sensors are disposed within the maximum sensing distance, even when an operation failure or an error is detected in one of the two unattended ground sensors, the seismic waves can be normally detected by using the other one of the two unattended ground sensors. In the conventional case where a position of a train is detected by using RFID tags, when an error has occurred in one of the RFID tags, the position of the train cannot be detected at a position where the RFID tag having the error is installed. However, according to the present invention, even when errors are detected in some of the unattended ground sensors, the position of the train can be normally detected by using other unattended ground sensors.

Meanwhile, when a movement of a human being, instead of the large-size object such as the train, is to be detected by using the unattended ground sensors <NUM>, a sensing distance of each of the unattended ground sensors <NUM> can be reduced. Each of the unattended ground sensors <NUM> is configured to detect the movement of the human being, e.g., within a range of <NUM> therearound. Therefore, in the train control system according to the present invention, when the control device <NUM> performs a second control mode to be described later, the positional distance between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> is set to be further reduced. In this case, the positional distance between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> may be set to <NUM> or more, and more preferably set to <NUM> or more considering the difference in weight of a human being.

Therefore, it is preferable that the positional distance between the two adjacent unattended ground sensors <NUM>-<NUM> and <NUM>-<NUM> among the unattended ground sensors <NUM> is set to be equal to or greater than <NUM>/<NUM> but equal to or less than <NUM>/<NUM> of the maximum sensing distance of each of the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM>.

Further, referring to <FIG>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> may communicate with one another through an ad-hoc wireless network. In other words, the unattended ground sensors <NUM> can be more efficiently and flexibly installed by allowing the unattended ground sensors <NUM> to communicate with one another through the ad-hoc wireless network without the aid of an access point (AP).

The control device <NUM> is configured to at least perform a first control mode for detecting a position of the train based on the data transmitted from the unattended ground sensors.

The control device <NUM> will be described in detail later.

The gateway <NUM> is configured to enable communication between the unattended ground sensors <NUM> and the control device <NUM>. For example, the gateway <NUM> receives data transmitted directly from each of the unattended ground sensors <NUM> or data transmitted from one or more of the unattended ground sensors <NUM> serving to collect data of other unattended ground sensors <NUM>. Then, the gateway <NUM> transmits the received data to the control device <NUM>.

Further, a plurality of the gateways <NUM> may be disposed. That is, the gateways <NUM> are disposed at different distances, and each of the gateways <NUM> preferably enables communication between the control device <NUM> and those of the unattended ground sensors <NUM> which are arranged within an area where the corresponding gateway is disposed.

As described above, the control device <NUM> is configured to at least perform the first control mode for detecting the position of the train based on the data transmitted from the unattended ground sensors <NUM>.

<FIG> shows an example in which the control device detects the position of the train based on the data transmitted from the unattended ground sensors in the train control system according to the present invention.

Referring to <FIG>, there is shown a configuration in which the position of the train is detected in real time by a first unattended ground sensor and a second unattended ground sensor while the train <NUM> is traveling on the train line <NUM>.

Here, the first unattended ground sensor and the second unattended ground sensor are designated among the unattended ground sensors <NUM>, and may be, e.g., the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> adjacent to each other or the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> that are not adjacent to each other.

In the following description, unless otherwise specified, it is assumed that the first unattended ground sensor is the unattended ground sensor <NUM>-<NUM> and the second unattended ground sensor is the unattended ground sensor <NUM>-<NUM>.

The control device <NUM> is configured to perform the first control mode in which the position of the train is detected.

More specifically, a seismic wave is generated when the train <NUM> travels on the train line <NUM>. The seismic wave is transmitted to each of the unattended ground sensors <NUM>, i.e., each of the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> through the ground surface.

A distance D between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> is inputted in advance. Further, a propagation velocity v of the seismic wave is also inputted in advance. Since the propagation velocity v of the seismic wave may vary depending on the state of the medium between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM>, it is preferable that the propagation velocity v is inputted in advance by obtaining it through the measurement.

The control device <NUM> receives data from each of the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> and, based on the received data, calculates time T1 at which the seismic wave generated by the train <NUM> arrives at the unattended ground sensor <NUM>-<NUM> and time T2 at which the seismic wave generated by the train <NUM> arrives at the unattended ground sensor <NUM>-<NUM>.

As shown in <FIG>, when a distance between the train <NUM> and the unattended ground sensor <NUM>-<NUM> is denoted by D1; a distance between the train <NUM> and the unattended ground sensor <NUM>-<NUM> is denoted by D2; and a difference between the time T2 at which the seismic wave arrives at the unattended ground sensor <NUM>-<NUM> and the time T1 at which the seismic wave arrives at the unattended ground sensor <NUM>-<NUM>, i.e., T2-T1, is denoted by Td, the following relationship is derived between the above parameters: <MAT><MAT><MAT><MAT><MAT>.

Therefore, the distance D1 between the train <NUM> and the unattended ground sensor <NUM>-<NUM> can be calculated on the basis of the distance D between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM>; the propagation velocity v of the seismic wave; and the difference between the time T2 at which the seismic wave arrives at the unattended ground sensor <NUM>-<NUM> and the time T1 at which the seismic wave arrives at the unattended ground sensor <NUM>-<NUM>.

Meanwhile, as described above, the unattended ground sensors <NUM>-<NUM> and <NUM>-<NUM> may be connected to the train line <NUM> through the sensing lines <NUM>-<NUM> and <NUM>-<NUM>, respectively. In this case, the propagation velocity v of the seismic wave can be inputted in advance by obtaining it through the measurement using train line <NUM> as the medium. In the case when the unattended ground sensors <NUM>-<NUM> and <NUM>-<NUM> are connected to the train line <NUM> through the sensing lines <NUM>-<NUM> and <NUM>-<NUM>, respectively, the distance D1 between the train <NUM> and the unattended ground sensor <NUM>-<NUM> can also be calculated on the basis of the distance D between the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM>; the propagation velocity v of the seismic wave; and the difference between the time T2 at which the seismic wave arrives at the unattended ground sensor <NUM>-<NUM> and the time T1 at which the seismic wave arrives at the unattended ground sensor <NUM>-<NUM>.

The control device <NUM> of the train control system according to the present invention may be configured to further perform other control modes as well as the first control mode for detecting the position of the train.

<FIG> shows examples of control modes that can be performed by the control device of the train control system according to the present invention.

Referring to <FIG>, the control device <NUM> may be configured to perform the second control mode, a third control mode, a fourth control mode, and a fifth control mode in addition to the first control mode. The third control mode includes a first operation mode and a second operation mode.

More specifically, the control device <NUM> may be configured to perform the second control mode in which safety information around the train line <NUM> is detected based on data transmitted from the unattended ground sensors <NUM>.

For example, the risk of railway casualty accidents is high when an operator performs railway maintenance operation on the train line <NUM> or a person moves around the train line <NUM>.

Therefore, the control device <NUM> detects vibrations around the train line <NUM> based on the data transmitted from the unattended ground sensors <NUM>, and then detects the safety information based on the detected results. For example, in <FIG>, when the control device <NUM> receives data from each of the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM>, the position where the vibration has occurred can be detected as described with reference to <FIG>. Therefore, it is possible to easily detect a specific position around the train line <NUM> where the safety-related problem has currently occurred.

The second control mode may be used to monitor the presence of an intruder around the train line <NUM>. For example, after the train operation is stopped, the control device <NUM> performs the second control mode to detect the vibration in the vicinity of the train line <NUM>. If the vibration is detected in the vicinity of the train line <NUM>, there is a possibility that the safety-related problem has occurred. Therefore, the system manager is able to monitor the train line <NUM> based on the second control mode.

Conventionally, an additional monitoring system for monitoring an intruder is required to be provided. However, according to the present invention, there is no need to provide the additional monitoring system since such vibration can be detected through the second control mode.

The control device <NUM> is configured to perform the third control mode. The third control mode includes the first operation mode in which the first control mode and the second control mode are performed together and the second operation mode in which one of the first control mode and the second control mode is performed, and the control device <NUM> performs the third control mode by selecting one of the first operation mode and the second operation mode according to a predetermined criterion.

In the first operation mode, the second control mode is performed together with the first control mode even while the train <NUM> is in operation. In this case, while the position of the train <NUM> is detected, the safety information can also be detected by detecting another vibration around the train line <NUM>.

In the second operation mode, for example, one of the first control mode and the second control mode is selected based on whether or not the train <NUM> is in operation, so that the first control mode is performed during which the train <NUM> is in operation and the second control mode is performed during which the train <NUM> is not in operation.

Further, the control device <NUM> may be configured to perform the fourth control mode for dynamically selecting the first unattended ground sensor and the second unattended ground sensor based on the operating state of each of the unattended ground sensors <NUM>. Referring back to <FIG>, four of the unattended ground sensors <NUM>, i.e., the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM>, the unattended ground sensor <NUM>-<NUM> and the unattended ground sensor <NUM>-<NUM> are provided. Further, for example, the position of the train <NUM> may be detected by using the unattended ground sensor <NUM>-<NUM> as the first unattended ground sensor and the unattended ground sensor <NUM>-<NUM> as the second unattended ground sensor, respectively, as shown in <FIG>. However, due to, e.g., the failure of the unattended ground sensor <NUM>-<NUM> or the circumstance around the unattended ground sensor <NUM>-<NUM>, the control device <NUM> may not normally receive data from the unattended ground sensor <NUM>-<NUM>.

Therefore, even when operation failures occur in some of the unattended ground sensors <NUM>, the control device <NUM> may detect the position of the train <NUM> by using other unattended ground sensors that are in normal operation.

Further, the control device <NUM> may be configured to perform the fifth control mode for detecting a maintenance-required unattended ground sensor among the unattended ground sensors <NUM> based on the operating state of each of the unattended ground sensors <NUM>.

As previously described, the control device <NUM> receives data directly from each of the unattended ground sensors <NUM> or from some of the unattended ground sensors that collect the data from other unattended ground sensors <NUM>, or the control device <NUM> receives data through the gateway <NUM>.

Therefore, the control device <NUM> may detect unattended ground sensors that are unable to generate data among the unattended ground sensors <NUM> and set such unattended ground sensor as the maintenance-required unattended ground sensors. The system manager may perform the maintenance operation for the detected unattended ground sensors through the fifth control mode.

Although various embodiments of the present disclosure have been described in detail, the above descriptions merely illustrate the technical idea of the present disclosure.

Therefore, the exemplary embodiments disclosed herein are not used to limit the technical idea of the present disclosure, but to explain the present disclosure, and the scope of the technical idea of the present disclosure is not limited by those embodiments. The scope of protection of the present invention is defined by the features of the following claims.

In accordance with one embodiment of the present disclosure, it is possible to provide a train control system capable of efficiently and accurately detecting a position of a train by using a plurality of unattended ground sensors while minimizing a cost required for maintenance.

Claim 1:
A train control system comprising:
a plurality of unattended ground sensors (<NUM>) installed along a train line (<NUM>); and
a control device (<NUM>) configured to perform a third control mode for performing one operation mode selected, according to a predetermined criterion, from a first operation mode and a second operation mode,
wherein, in the first operation mode, a first control mode for detecting a position of a train (<NUM>) based on data transmitted from the unattended ground sensors (<NUM>) when the train (<NUM>) travels on the train line (<NUM>) is performed together with a second control mode for detecting safety information around the train line (<NUM>) based on the data transmitted from the unattended ground sensors (<NUM>) when vibrations around the train line (<NUM>) is detected, and in the second operation mode, either the first control mode or the second control mode is performed.