RAILROAD MANAGEMENT SYSTEM, TRACK SENSING DEVICE, TRACK SENSING METHOD, CONTROL CIRCUIT, AND STORAGE MEDIUM

Abstract

A railroad management system includes: a plurality of first wireless terminals provided corresponding to a plurality of tracks, and each installed at an end of a platform of a corresponding track; a second wireless terminal installed at an end of a train, and configured to perform communication with the first wireless terminals using an ultra-wide band wireless signal; a distance estimation unit that estimates a distance between each of the plurality of first wireless terminals and the second wireless terminal using the ultra-wide band wireless signal; and a track sensing unit that senses a track that the train is entering based on an estimation result from the distance estimation unit.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a railroad management system using ultra-wide band (UWB) communication, a track sensing device, a track sensing method, a control circuit, and a storage medium.

2. Description of the Related Art

On station platforms, in order to prevent passengers from falling onto the railroad tracks, platform gates are introduced that open only when the train doors are opened after the train stops, or safety of the passengers is monitored using monitoring cameras that capture the platforms. In order to achieve safer railroad systems, it is important to sense which track of the station the train has entered.

Japanese Patent No. 5517706 discloses a technique of associating a platform with a train when the train enters the platform and stops by means of narrow-area communication using a low frequency (LF) band of 30 to 300 KHz.

However, the technique disclosed in Japanese Patent No. 5517706 is problematic in that radio waves travel too far due to the use of the LF band, resulting in a high possibility of erroneous sensing of the track that the train is entering.

SUMMARY OF THE INVENTION

In order to solve the above problem and achieve the object, a railroad management system according to the present disclosure includes: a plurality of first wireless terminals provided corresponding to a plurality of tracks, and each installed at an end of a platform of a corresponding track; a second wireless terminal installed at an end of a train, and configured to perform communication with the first wireless terminals using an ultra-wide band wireless signal; a distance estimation unit to estimate a distance between each of the plurality of first wireless terminals and the second wireless terminal using the ultra-wide band wireless signal; and a track sensing unit to sense a track that the train is entering based on an estimation result from the distance estimation unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a railroad management system according to a first embodiment;

FIG. 2 is a diagram illustrating a configuration of the first UWB terminal illustrated in FIG. 1;

FIG. 3 is a diagram illustrating a configuration of the second UWB terminal illustrated in FIG. 1;

FIG. 4 is a sequence diagram illustrating a communication sequence of the railroad management system according to the first embodiment;

FIG. 5 is a sequence diagram illustrating a communication sequence of the railroad management system according to a second embodiment;

FIG. 6 is a sequence diagram illustrating a communication sequence on the inbound side of the railroad management system according to a third embodiment;

FIG. 7 is a sequence diagram illustrating a communication sequence on the outbound side of the railroad management system according to the third embodiment;

FIG. 8 is a sequence diagram illustrating a communication sequence of the railroad management system according to a fourth embodiment;

FIG. 9 is a diagram illustrating a configuration of a railroad management system according to a fifth embodiment;

FIG. 10 is a diagram illustrating a functional configuration of the first UWB terminal illustrated in FIG. 9;

FIG. 11 is a diagram illustrating a functional configuration of the second UWB terminal illustrated in FIG. 9;

FIG. 12 is a diagram illustrating a functional configuration of the communication terminal illustrated in FIG. 9;

FIG. 13 is a sequence diagram illustrating a communication sequence of the railroad management system according to the fifth embodiment;

FIG. 14 is a diagram illustrating a functional configuration of a communication terminal according to a sixth embodiment;

FIG. 15 is a sequence diagram illustrating a communication sequence of the railroad management system according to the sixth embodiment;

FIG. 16 is a diagram illustrating a configuration of a railroad management system according to a seventh embodiment;

FIG. 17 is a diagram illustrating a functional configuration of the second UWB terminal illustrated in FIG. 16;

FIG. 18 is a sequence diagram illustrating a communication sequence of the railroad management system according to the seventh embodiment;

FIG. 19 is a diagram illustrating a configuration of a railroad management system according to an eighth embodiment;

FIG. 20 is a sequence diagram illustrating a communication sequence of the railroad management system according to the eighth embodiment;

FIG. 21 is a diagram illustrating a configuration of a railroad management system according to a ninth embodiment;

FIG. 22 is a diagram illustrating a functional configuration of the communication terminal illustrated in FIG. 21;

FIG. 23 is a sequence diagram illustrating a communication sequence of the railroad management system according to the ninth embodiment;

FIG. 24 is a diagram illustrating a configuration of a railroad management system according to a tenth embodiment;

FIG. 25 is a sequence diagram illustrating a communication sequence of the railroad management system according to the tenth embodiment;

FIG. 26 is a diagram illustrating a configuration of a railroad management system according to an eleventh embodiment;

FIG. 27 is a diagram illustrating a functional configuration of the on-board wireless device illustrated in FIG. 26;

FIG. 28 is a diagram illustrating a functional configuration of the camera wireless device illustrated in FIG. 26;

FIG. 29 is a sequence diagram illustrating a communication sequence of the railroad management system according to the eleventh embodiment;

FIG. 30 is a sequence diagram illustrating a communication sequence of the railroad management system according to a twelfth embodiment;

FIG. 31 is a diagram illustrating a configuration of a railroad management system according to a thirteenth embodiment;

FIG. 32 is a diagram illustrating a functional configuration of the camera wireless device illustrated in FIG. 31;

FIG. 33 is a diagram illustrating a functional configuration of the core server illustrated in FIG. 31;

FIG. 34 is a sequence diagram illustrating a communication sequence of the railroad management system according to the thirteenth embodiment;

FIG. 35 is a diagram illustrating dedicated hardware for implementing the functions of the components of the railroad management systems according to the first to thirteenth embodiments; and

FIG. 36 is a diagram illustrating an example of a control circuit for implementing the functions of the components of the railroad management systems according to the first to thirteenth embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a railroad management system, a track sensing device, a track sensing method, a control circuit, and a storage medium according to embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the technical scope of the present disclosure is not limited by the following embodiments.

First Embodiment

FIG. 1 is a diagram illustrating a configuration of a railroad management system 1 according to the first embodiment. The railroad management system 1 includes first UWB terminals 12-a-1 to 12-d-1 and 12-a-2 to 12-d-2, which are a plurality of first wireless terminals installed at the ends of the platforms, and second UWB terminals 14-a and 14-b, which are second wireless terminals installed at the ends of a train 13 and configured to perform ultra-wide band wireless communication with the first wireless terminals. Note that four railroad tracks are provided for the platforms of the station illustrated in FIG. 1, and each railroad track is denoted by a number. Hereinafter, the four railroad tracks are referred to as the tracks 11-a to 11-d. The first UWB terminals 12-a-1 to 12-d-1 and 12-a-2 to 12-d-2 are provided corresponding to the tracks 11-a to 11-d, respectively. Here, ultra-wide band wireless communication, also called UWB, is a wireless technology defined by the Federal Communication Commission (FCC), and uses wireless signals having a fractional bandwidth (FBW) of 20% or more or 500 MHz or more. Wireless signals that are used in ultra-wide band wireless communication are called ultra-wide band wireless signals, UWB signals, and the like.

Here, the train 13 can travel in a first direction or a second direction opposite to the first direction, and the traveling direction illustrated in FIG. 1 is the first direction. Here, the route on which the train 13 travels connects an urban area and a suburb, and the first direction is the outbound direction from the urban area to the suburb. Hereinafter, the front side with respect to the train 13 traveling in the first direction may be referred to as the outbound side, and the rear side with respect to the train 13 traveling in the first direction may be referred to as the inbound side. The pair of first UWB terminals 12-a-1 and 12-a-2 are installed at the both ends of the platform of the track 11-a. Specifically, the first UWB terminal 12-a-1 is installed on the inbound side, and the first UWB terminal 12-a-2 is installed on the outbound side. The pair of first UWB terminals 12-b-1 and 12-b-2 are installed at the both ends of the platform of the track 11-b. Specifically, the first UWB terminal 12-b-1 is installed on the inbound side, and the first UWB terminal 12-b-2 is installed on the outbound side. The pair of first UWB terminals 12-c-1 and 12-c-2 are installed at the both ends of the platform of the track 11-c. Specifically, the first UWB terminal 12-c-1 is installed on the inbound side, and the first UWB terminal 12-c-2 is installed on the outbound side. The pair of first UWB terminals 12-d-1 and 12-d-2 are installed at the both ends of the platform of the track 11-d. Specifically, the first UWB terminal 12-d-1 is installed on the inbound side, and the first UWB terminal 12-d-2 is installed on the outbound side. The second UWB terminal 14-a is installed at the inbound-side end of the train 13, and the second UWB terminal 14-b is installed at the outbound-side end of the train 13. The tracks 11-a and 11-b belong to a route 15-a, and the tracks 11-c and 11-d belong to a route 15-b. The train 13 travels on a railroad track of the route 15-a. FIG. 1 illustrates the train 13 about to enter the track 11-b. Hereinafter, components having similar functions are distinguished from each other by being denoted by a common number with a hyphen and a different alphabet letter or a different number. In cases where a plurality of components having similar functions need not be distinguished from each other, they may be denoted by only a common number. For example, in cases where the first UWB terminals 12-a-1 to 12-d-1 and 12-a-2 to 12-d-2 need not be distinguished from each other, they are simply referred to as the first UWB terminal (s) 12.

FIG. 2 is a diagram illustrating a configuration of the first UWB terminal 12 illustrated in FIG. 1. Note that FIG. 2 illustrates functions necessary for the description of the first embodiment, and the first UWB terminal 12 may have functions other than those illustrated in FIG. 2. The first UWB terminal 12 includes a preamble signal generation unit 121, a data signal generation unit 122, a signal detection unit 123, a reception timing estimation unit 124, a data signal demodulation unit 125, and an UWB antenna 126.

The preamble signal generation unit 121 generates a preamble signal that is a signal detection signal for use in detecting a signal on the reception side, and outputs the generated preamble signal to the data signal generation unit 122. The data signal generation unit 122 modulates the data to be transmitted, generates a transmission signal that is a data signal based on the modulated data and the preamble signal, and outputs the generated transmission signal to the UWB antenna 126. The signal detection unit 123 detects the preamble signal included in the reception signal received by the UWB antenna 126, and notifies the reception timing estimation unit 124 and the data signal demodulation unit 125 of the timing of detection of the preamble signal. The reception timing estimation unit 124 estimates the reception timing of the signal based on the timing of detection of the preamble signal at the signal detection unit 123. The data signal demodulation unit 125 demodulates the data signal included in the reception signal received by the UWB antenna 126 based on the timing of detection of the preamble signal provided from the signal detection unit 123. The UWB antenna 126 outputs the reception signal that is the signal received to the signal detection unit 123 and the data signal demodulation unit 125, and transmits the transmission signal generated by the data signal generation unit 122.

FIG. 3 is a diagram illustrating a configuration of the second UWB terminal 14 illustrated in FIG. 1. Note that FIG. 3 illustrates functions necessary for the description of the first embodiment, and the second UWB terminal 14 may have functions other than those illustrated in FIG. 3. The second UWB terminal 14 includes the preamble signal generation unit 121, the data signal generation unit 122, the signal detection unit 123, the reception timing estimation unit 124, the data signal demodulation unit 125, the UWB antenna 126, a distance estimation unit 141, and a track sensing unit 142. Note that components having the same functions as those of the first UWB terminal 12 illustrated in FIG. 2 are denoted by the same reference signs, and a detailed description thereof will be omitted. Hereinafter, differences from the first UWB terminal 12 will be mainly described.

The reception timing estimation unit 124 notifies the distance estimation unit 141 of the estimated reception timing. The data signal demodulation unit 125 outputs the demodulated data signal to the distance estimation unit 141. The distance estimation unit 141 estimates the distance between the second UWB terminal 14 and each of the plurality of first UWB terminals 12 based on the reception timing estimated by the reception timing estimation unit 124 and the demodulated data signal output by the data signal demodulation unit 125. The distance estimation unit 141 outputs the estimation result to the track sensing unit 142. The track sensing unit 142 senses the track that the train 13 equipped with the second UWB terminal 14 is entering based on the estimation result output by the distance estimation unit 141. The track sensing unit 142 transmits a track sensing signal indicating the sensed track to the first UWB terminal 12 corresponding to the sensed track.

FIG. 4 is a sequence diagram illustrating a communication sequence of the railroad management system 1 according to the first embodiment. FIG. 4 illustrates the communication sequence in which the train 13 is traveling in the traveling direction from the urban area to the suburb and is about to enter the track 11-b of the platform of the station as illustrated in FIG. 1. Among the second UWB terminals 14-a and 14-b installed on the train 13, the second UWB terminal 14-b located on the front side in the traveling direction periodically transmits a ranging start signal 16 for announcing the presence of the second UWB terminal 14-b (step S10).

Here, suppose that the first UWB terminals 12-a-1 to 12-d-1 installed on the inbound side of the platforms have successfully received the ranging start signal 16. In this case, if each of the first UWB terminals 12-a-1 to 12-d-1 has not sensed any other vehicle entering the corresponding tracks 11-a to 11-d, the first UWB terminals 12-a-1 to 12-d-1 respectively transmit response signals 17-a to 17-d to the second UWB terminal 14-b at a predetermined timing in response to receiving the ranging start signal 16 (step S11). The response signals 17-a to 17-d include information indicating the track 11 on which the corresponding first UWB terminals 12-a-1 to 12-d-1 are installed. The distance estimation unit 141 of the second UWB terminal 14-b that has received the response signals 17-a to 17-d estimates the distance to each of the first UWB terminals 12-a-1 to 12-d-1 based on the timing of receiving the response signals 17-a to 17-d, and outputs the estimation result to the track sensing unit 142. The track sensing unit 142 senses the track 11 that the train 13 is entering based on whether the estimation result of the distance satisfies a predetermined condition. For example, when the estimated distance to some first UWB terminal 12 becomes equal to or below a predetermined threshold, the track sensing unit 142 senses the track 11 corresponding to this first UWB terminal 12 as the track 11 that the train 13 is entering.

When there is no estimation result satisfying the condition, the second UWB terminal 14-b transmits the ranging start signal 16 again (step S12). The first UWB terminals 12-a-1 to 12-d-1 that have received the ranging start signal 16 respectively transmit the response signals 17-a to 17-d again (step S13). The second UWB terminal 14-b that has received the response signals 17-a to 17-d repeats the process of estimating the distance to each of the first UWB terminals 12-a-1 to 12-d-1 and the process of track sensing.

When there is an estimation result satisfying the condition, the second UWB terminal 14-b sets the track 11 corresponding to the first UWB terminal 12 associated with the estimation result of the distance satisfying the condition as the track 11 that the train 13 is entering. The second UWB terminal 14-b transmits a track sensing signal 18 indicating the sensed track 11-b to the first UWB terminal 12-b-1 installed on the sensed track 11-b (step S14). The track sensing signal 18 includes the identifier of the train 13 and indicates that the train 13 has entered the track 11-b.

As described above, the railroad management system 1 according to the first embodiment senses the track 11 that the train 13 is entering based on the estimation result of the distance between the first UWB terminal 12 and the second UWB terminal 14 using ultra-wide band wireless. Because ultra-wide band wireless has a narrower reach of radio waves than radio waves in the LF band and the like and is suitable for track sensing, it is possible to reduce erroneous sensing of the track 11 and to improve the accuracy of sensing the track 11 that the train 13 is entering. Because the track sensing signal 18 indicating the track 11 sensed by the second UWB terminal 14-b is transmitted to the first UWB terminal 12-b-1, it is possible to enhance the safety of the railroad management system 1 by controlling the railroad management system 1 using information of the track 11 sensed with high accuracy, which is not described in detail in the first embodiment.

Second Embodiment

In the second embodiment, the railroad management system 1 has a configuration similar to that in the first embodiment. Hereinafter, differences from the first embodiment will be mainly described. FIG. 5 is a sequence diagram illustrating a communication sequence of the railroad management system 1 according to the second embodiment.

The second UWB terminal 14-b located on the front side in the traveling direction of the train 13 periodically transmits a ranging start signal 16A using the preamble signal generated using the route identifier indicating the route 15-a to which the train 13 belongs (step S20).

Each of the first UWB terminals 12-a-1 to 12-d-1 that has received the ranging start signal 16A performs signal detection processing using the route identifier indicating the route to which the track 11 corresponding to each of the first UWB terminals 12-a-1 to 12-d-1 belongs. Therefore, among the first UWB terminals 12-a-1 to 12-d-1, the first UWB terminals 12-a-1 and 12-b-1 whose route identifiers match with each other can detect the ranging start signal 16A, and the other first UWB terminals 12 cannot detect the ranging start signal 16A. The first UWB terminals 12-a-1 and 12-b-1 that have detected the ranging start signal 16A transmit response signals 17A-a and 17A-b using the preamble signal generated using the route identifier indicating the route 15-a at a predetermined timing (step S21). The response signals 17A-a and 17A-b include information indicating the tracks 11-a and 11-b on which the corresponding first UWB terminals 12-a-1 and 12-b-1 are installed. The distance estimation unit 141 of the second UWB terminal 14-b that has received the response signals 17A-a and 17A-b estimates the distance to each of the first UWB terminals 12-a-1 and 12-b-1 based on the timing of receiving the response signals 17A-a and 17A-b, and outputs the estimation result to the track sensing unit 142. The track sensing unit 142 senses the track 11 that the train 13 is entering based on whether the estimation result of the distance satisfies a predetermined condition. For example, when the estimated distance to some first UWB terminal 12 becomes equal to or below a predetermined threshold, the track sensing unit 142 senses the track 11 corresponding to this first UWB terminal 12 as the track 11 that the train 13 is entering.

When there is no estimation result satisfying the condition, the second UWB terminal 14-b transmits the ranging start signal 16A again (step S22). Among the first UWB terminals 12-a-1 to 12-d-1 that have received the ranging start signal 16A, the first UWB terminals 12-a-1 and 12-b-1 that have successfully detected the ranging start signal 16A transmit the response signals 17A-a and 17A-b again (step S23). The second UWB terminal 14-b that has received the response signals 17A-a and 17A-b repeats the process of estimating the distance to each of the first UWB terminals 12-a-1 and 12-b-1 and the process of track sensing.

When there is an estimation result satisfying the condition, the second UWB terminal 14-b sets the track 11 corresponding to the first UWB terminal 12 associated with the estimation result of the distance satisfying the condition as the track 11 that the train 13 is entering. The second UWB terminal 14-b transmits the track sensing signal 18 indicating the sensed track 11-b to the first UWB terminal 12-b-1 installed on the sensed track 11-b (step S24). The track sensing signal 18 includes the identifier of the train 13 and indicates that the train 13 has entered the track 11-b.

As described above, in the railroad management system 1 according to the second embodiment, the second UWB terminal 14 transmits the ranging start signal 16A using the preamble signal generated using the route identifier of the corresponding track 11, and the first UWB terminal 12 performs signal detection processing using the preamble signal generated using the route identifier of the corresponding track 11. Therefore, the first UWB terminal 12, which is a first wireless terminal, uses a signal detection signal different for each route of the corresponding track 11, and the second UWB terminal 14, which is a second wireless terminal, uses a signal detection signal different for each route of the train 13 equipped with the second UWB terminal 14. As a result, the process of estimating the distance and sensing the track 11 is performed only between the first UWB terminal 12 and the second UWB terminal 14 associated with the same route, and it is possible to accurately sense the track 11 to enter for each route.

In the first and second embodiments, the second UWB terminal 14 installed on the train 13 transmits the ranging start signals 16 and 16A, and performs the process of estimating the distance to the first UWB terminal 12 installed on each platform. However, the ranging start signals 16 and 16A may be transmitted from the first UWB terminal 12. In the case where the first UWB terminal 12 transmits the ranging start signals 16 and 16A, the first UWB terminal 12 has the configuration illustrated in FIG. 3 and the second UWB terminal 14 has the configuration illustrated in FIG. 2.

Third Embodiment

The configuration of the railroad management system 1 according to the third embodiment is similar to that in the first embodiment. Hereinafter, differences from the first embodiment will be mainly described. FIG. 6 is a sequence diagram illustrating a communication sequence on the inbound side of the railroad management system 1 according to the third embodiment. FIG. 7 is a sequence diagram illustrating a communication sequence on the outbound side of the railroad management system 1 according to the third embodiment. FIGS. 6 and 7 illustrate communication sequences that occur after the train 13 enters the track 11-b and stops.

In the third embodiment, after the track 11 that the train 13 is entering is sensed, the process of estimating the distance between the first UWB terminal 12 and the second UWB terminal 14 using ultra-wide band wireless is performed, and the process of track sensing is performed based on the estimation result. At this time, among the first UWB terminals 12-a-1 to 12-d-1 and 12-a-2 to 12-d-2 installed at the both ends of the platforms, the first UWB terminals 12-a-1 to 12-d-1 installed on the inbound side of the platforms use preamble signals different from the preamble signals of the first UWB terminals 12-a-2 to 12-d-2 installed on the outbound side of the platforms, and identical to the preamble signal of the second UWB terminal 14-a installed on the inbound side among the second UWB terminals 14-a and 14-b installed at the both ends of the train 13. The first UWB terminals 12-a-2 to 12-d-2 installed on the outbound side of the platforms use the same preamble signal as the second UWB terminal 14-b installed on the outbound side of the train 13. The inbound side of the platforms or the train 13 can be rephrased as the rear side with respect to the train 13 traveling in the first direction which is the traveling direction illustrated in FIG. 1, and the outbound side of the platforms or the train 13 can be rephrased as the front side with respect to the train 13 traveling in the first direction. The fact that the first UWB terminal 12 and the second UWB terminal 14 use the same preamble signal means that the reception side can detect the signal transmitted by the transmission side among the first UWB terminal 12 and the second UWB terminal 14.

After the train 13 stops, the second UWB terminal 14-a installed on the train 13 transmits a ranging start signal 16-a (step S30-1), and the second UWB terminal 14-b transmits a ranging start signal 16-b (step S30-2). Different preamble signals are used for the ranging start signal 16-a and the ranging start signal 16-b, respectively. Each of the first UWB terminals 12-a-1 to 12-d-1 that has received the ranging start signal 16-a performs signal detection using the same preamble signal as the second UWB terminal 14-a; therefore, the first UWB terminals 12-a-1 to 12-d-1 are capable of detecting the ranging start signal 16-a, and transmit response signals 17-a-1 to 17-d-1 at a predetermined timing (step S31-1). Each of the first UWB terminals 12-a-2 to 12-d-2 that has received the ranging start signal 16-b performs signal detection using the same preamble signal as the second UWB terminal 14-b; therefore, the first UWB terminals 12-a-2 to 12-d-2 are capable of detecting the ranging start signal 16-b, and transmit response signals 17-a-2 to 17-d-2 at a predetermined timing (step S31-2). At this time, the first UWB terminals 12-a-1 to 12-d-1 respectively transmit the response signals 17-a-1 to 17-d-1 using a preamble signal that can be detected by the second UWB terminal 14-a, and the first UWB terminals 12-a-2 to 12-d-2 respectively transmit the response signals 17-a-2 to 17-d-2 using a preamble signal that can be detected by the second UWB terminal 14-b. For the response signals 17-a-1 to 17-d-1, preamble signals different from those for the response signals 17-a-2 to 17-d-2 are used. The response signal 17 includes information indicating the track 11 on which the corresponding first UWB terminal 12 is installed.

The second UWB terminal 14-a that has received the response signals 17-a-1 to 17-d-1 estimates, at the distance estimation unit 141, the distance to each of the first UWB terminals 12-a-1 to 12-d-1 installed on the platforms using the response signals 17-a-1 to 17-d-1. In addition, the second UWB terminal 14-b that has received the response signals 17-a-2 to 17-d-2 estimates, at the distance estimation unit 141, the distance to each of the first UWB terminals 12-a-2 to 12-d-2 installed on the platforms using the response signals 17-a-2 to 17-d-2. Each of the second UWB terminals 14-a and 14-b determines at the track sensing unit 142 whether the estimation result of the distance satisfies the condition based on the estimation result from the distance estimation unit 141.

When the estimation result does not satisfy the condition, the second UWB terminal 14-a transmits the ranging start signal 16-a again (step S32-1), and the response signals 17-a-1 to 17-d-1 are transmitted respectively from the first UWB terminals 12-a-1 to 12-d-1 in response to the ranging start signal 16-a (step S33-1). Similarly, when the estimation result does not satisfy the condition, the second UWB terminal 14-b transmits the ranging start signal 16-b again (step S32-2), and the response signals 17-a-2 to 17-d-2 are transmitted respectively from the first UWB terminals 12-a-2 to 12-d-2 in response to the ranging start signal 16-b (step S33-2). The second UWB terminal 14-a that has received the response signals 17-a-1 to 17-d-1 repeats the estimation of the distance to each of the first UWB terminals 12-a-1 to 12-d-1 and the process of track sensing using the response signals 17-a-1 to 17-d-1. When the estimation result satisfies the condition, the second UWB terminal 14-a transmits the track sensing signal 18 indicating the sensed track 11 to the first UWB terminal 12-b-1 (step S34-1), and the second UWB terminal 14-b transmits the track sensing signal 18 indicating the sensed track 11 to the first UWB terminal 12-b-2 (step S34-2). The communication sequence illustrated in FIG. 6 and the communication sequence illustrated in FIG. 7 described above may be executed simultaneously in parallel, and can be executed asynchronously.

Note that the second UWB terminals 14-a and 14-b installed at the both ends of the train 13 can separately perform the process of track sensing and transmit the track sensing signals 18 indicating the respective sensing results to the first UWB terminals 12 installed on the platforms. Alternatively, upon finding the track 11 associated with the estimation result of the distance equal to or less than the threshold, the second UWB terminals 14-a and 14-b may notify each other of the sensing results of the tracks 11, and generate and transmit the track sensing signals 18 to the first UWB terminals 12 at the time when both of the second UWB terminals 14-a and 14-b sense the track 11 to enter.

As described above, in the railroad management system 1 according to the third embodiment, when the distance is estimated between the first UWB terminal 12 and the second UWB terminal 14, the first UWB terminals 12-a-1 to 12-d-1 and the second UWB terminal 14-a installed on the inbound side and the first UWB terminals 12-a-2 to 12-d-2 and the second UWB terminal 14-b installed on the outbound side use different preamble signals. Therefore, the respective processes of distance estimation can be performed asynchronously.

In the third embodiment, the ranging start signal 16 is transmitted from the second UWB terminal 14 installed on the train 13 toward the first UWB terminal 12 installed on the platform, and the process of distance estimation and the process of track sensing are performed in the second UWB terminal 14. However, the ranging start signal 16 may be transmitted from the first UWB terminal 12 installed on the platform, and the process of distance estimation and the process of track sensing may be performed in the first UWB terminal 12.

Fourth Embodiment

The configuration of the railroad management system 1 according to the fourth embodiment is similar to that in the first embodiment. Hereinafter, differences from the first embodiment will be mainly described. FIG. 8 is a sequence diagram illustrating a communication sequence of the railroad management system 1 according to the fourth embodiment.

The first UWB terminals 12-a-1 to 12-d-1 respectively transmit annunciation signals 19-a-1 to 19-d-1 in a time division manner (step S1). Upon receiving the annunciation signals 19-a-1 to 19-d-1, the second UWB terminal 14-b selects, based on the received annunciation signals 19-a-1 to 19-d-1, the first UWB terminal 12 to be subjected to ranging from among the first UWB terminals 12-a-1 to 12-d-1-that are the transmission sources of the annunciation signals 19-a-1 to 19-d-1. For example, the second UWB terminal 14-b can select the first UWB terminal 12 to be subjected to ranging based on the reception strength of the annunciation signal 19, the position information of the first UWB terminal 12 included in the annunciation signal 19, the position of the first UWB terminal 12 pre-registered in the on-board database, and the like. The second UWB terminal 14-b transmits a ranging start signal 16B (step S2). At this time, the ranging start signal 16B includes information for identifying the selected first UWB terminals 12-a-1, 12-b-1, and 12-c-1, and information indicating the respective transmission timings of the selected first UWB terminals 12-a-1, 12-b-1, and 12-c-1.

Each of the first UWB terminals 12-a-1 to 12-d-1 that have received the ranging start signal 16B determines based on the ranging start signal 16B whether each of the first UWB terminal 12-a-1, 12-b-1, or 12-c-1 itself is selected one, and transmits the response signal 17 at the timing indicated by the ranging start signal 16B in response to determining that it is the first UWB terminal 12 selected to be subjected to ranging. Here, since the first UWB terminals 12 to be subjected to ranging are the first UWB terminals 12-a-1, 12-b-1, and 12-c-1, the first UWB terminals 12-a-1, 12-b-1, and 12-c-1 respectively transmit response signals 17-a-1, 17-b-1, and 17-c-1 (step S3). The second UWB terminal 14-b that has received the response signal 17 estimates the distance to the first UWB terminal 12 based on the received response signal 17. Here, the second UWB terminal 14-b estimates the distance to each of the first UWB terminals 12-a-1, 12-b-1, and 12-c-1, and the process of estimating the distance between the second UWB terminal 14-b and the first UWB terminal 12-d-1 is skipped.

After transmitting the response signal 17, the first UWB terminals 12-a-1 to 12-d-1 respectively transmit the annunciation signals 19-a-1 to 19-d-1 again (step S4), and the process of ranging including the transmission of the ranging start signal 16B (step S5) and the transmission of the response signals 17-a-1 to 17-d-1 (step S6) is repeated. Upon sensing the track 11 that the train 13 is entering based on the estimated distance, the second UWB terminal 14-b transmits the track sensing signal 18 indicating the sensed track 11 (step S7).

As described above, in the railroad management system 1 according to the fourth embodiment, after the annunciation signal 19 is transmitted from the first UWB terminal 12 to the second UWB terminal 14, the second UWB terminal 14 selects the first UWB terminal 12 as a ranging target based on the annunciation signal 19. Then, only the selected first UWB terminal 12 returns the response signal 17, the process of distance estimation is performed only with the selected first UWB terminal 12, and the process of distance estimation with the unselected first UWB terminal 12 is skipped. Therefore, the number of first UWB terminals 12 that transmit the response signal 17 can be reduced, and the efficiency of the process of ranging can be improved.

Fifth Embodiment

FIG. 9 is a diagram illustrating a configuration of a railroad management system 2 according to the fifth embodiment. The railroad management system 2 includes the four tracks 11-a to 11-d, first UWB terminals 22-a-1 to 22-d-1 and 22-a-2 to 22-d-2 provided corresponding to the tracks 11-a to 11-d as first wireless terminals installed at the ends of the platforms of the corresponding tracks, the train 13, second UWB terminals 24-a and 24-b installed at the ends of the train 13 as second wireless terminals that perform ultra-wide band wireless communication with the first wireless terminals, and a communication terminal 26 that can communicate with each of the plurality of first UWB terminals 22-a-1 to 22-d-1 and 22-a-2 to 22-d-2. Hereinafter, functions similar to those of the railroad management system 1 illustrated in FIG. 1 are denoted by the same reference signs, whereby a detailed description thereof will be omitted.

The pair of first UWB terminals 22-a-1 and 22-a-2 are installed at the both ends of the platform of the track 11-a. Specifically, the first UWB terminal 22-a-1 is installed on the inbound side, and the first UWB terminal 22-a-2 is installed on the outbound side. The pair of first UWB terminals 22-b-1 and 22-b-2 are installed at the both ends of the platform of the track 11-b. Specifically, the first UWB terminal 22-b-1 is installed on the inbound side, and the first UWB terminal 22-b-2 is installed on the outbound side. The pair of first UWB terminals 22-c-1 and 22-c-2 are installed at the both ends of the platform of the track 11-c. Specifically, the first UWB terminal 22-c-1 is installed on the inbound side, and the first UWB terminal 22-c-2 is installed on the outbound side. The pair of first UWB terminals 22-d-1 and 22-d-2 are installed at the both ends of the platform of the track 11-d. Specifically, the first UWB terminal 22-d-1 is installed on the inbound side, and the first UWB terminal 22-d-2 is installed on the outbound side. The second UWB terminal 24-a is installed at the inbound-side end of the train 13, and the second UWB terminal 24-b is installed at the outbound-side end of the train 13. Similarly to FIG. 1, FIG. 9 illustrates the train 13 about to enter the track 11-b.

FIG. 10 is a diagram illustrating a functional configuration of the first UWB terminal 22 illustrated in FIG. 9. The first UWB terminal 22 includes the preamble signal generation unit 121, the data signal generation unit 122, the signal detection unit 123, the reception timing estimation unit 124, the data signal demodulation unit 125, the UWB antenna 126, the distance estimation unit 141, a transmission/reception unit 221 for wireless communication, and a communication antenna 222 for wireless communication. The transmission/reception unit 221 performs signal processing for transmission/reception to/from the communication terminal 26. The communication antenna 222 can communicate with the communication terminal 26. The first UWB terminal 22 estimates the distance to the second UWB terminal 24 at the distance estimation unit 141, then generates a signal including the estimation result at the transmission/reception unit 221, and transmits the signal including the estimation result from the communication antenna 222 toward the communication terminal 26.

FIG. 11 is a diagram illustrating a functional configuration of the second UWB terminal 24 illustrated in FIG. 9. The second UWB terminal 24 includes the preamble signal generation unit 121, the data signal generation unit 122, the signal detection unit 123, the reception timing estimation unit 124, the data signal demodulation unit 125, and the UWB antenna 126. Because the second UWB terminal 24 has a functional configuration similar to that of the first UWB terminal 12 illustrated in FIG. 2, a detailed description thereof is omitted here.

FIG. 12 is a diagram illustrating a functional configuration of the communication terminal 26 illustrated in FIG. 9. The communication terminal 26 includes a communication antenna 261 for wireless communication, a transmission signal generation unit 262, a data signal demodulation unit 263, a track sensing unit 264, and a data server 265. The communication antenna 261 can wirelessly communicate with the second UWB terminal 24 using a scheme different from ultra-wide band wireless, and is configured to transmit the transmission signal output from the transmission signal generation unit 262 and output the reception signal to the data signal demodulation unit 263. The transmission signal generation unit 262 generates the transmission signal to be transmitted by wireless communication, and outputs the generated transmission signal to the communication antenna 261. The data signal demodulation unit 263 demodulates the data signal included in the reception signal received by the communication antenna 261, and outputs the demodulated data to the track sensing unit 264. The track sensing unit 264 causes the data server 265 to store the distance estimation result included in the reception signal from the first UWB terminal 22, and senses the track 11 that the train 13 is entering based on the distance estimation result.

FIG. 13 is a sequence diagram illustrating a communication sequence of the railroad management system 2 according to the fifth embodiment. The first UWB terminals 22-a-1 to 22-d-1 respectively transmit ranging start signals 27-a to 27-d to the second UWB terminal 24-b at a predetermined timing (step S40). After receiving the last ranging start signal 27, the second UWB terminal 24-b installed on the train 13 transmits a response signal 28 (step S41). At this time, the response signal 28 includes the reception timing of the ranging start signal 27 and the transmission timing of the response signal 28.

The first UWB terminals 22-a-1 to 22-d-1 that have received the response signal 28 estimate the distance to the second UWB terminal 24, and respectively transmit distance estimation results 29-a to 29-d to the communication terminal 26 (step S42). The communication terminal 26 saves the received distance estimation results 29-a to 29-d in the data server 265, and performs the process of track sensing based on the distance estimation results 29-a to 29-d.

The first UWB terminals 22-a-1 to 22-d-1 continue the transmission of the ranging start signals 27-a to 27-d, respectively (step S43). The second UWB terminal 24-b that has received the ranging start signals 27-a to 27-d transmits the response signal 28 after receiving the last ranging start signal 27 (step S44).

The first UWB terminals 22-a-1 to 22-d-1 that have received the response signal 28 continue the process of estimating the distance to the second UWB terminal 24 and transmitting the distance estimation results 29-a to 29-d respectively to the communication terminal 26 (step S45). Upon receiving the distance estimation results 29-a to 29-d, the communication terminal 26 saves the received distance estimation results 29-a to 29-d in the data server 265, and performs the process of track sensing based on the distance estimation results 29-a to 29-d. The track sensing unit 264 of the communication terminal 26 can identify the track 11, which corresponds to the first UWB terminal 22 having the distance estimation result 29 with a value equal to or less than the threshold, as the track 11 that the train 13 is entering. For example, when the distance estimation result 29-b received from the first UWB terminal 22-b-1 falls to or below the threshold, the track sensing unit 264 of the communication terminal 26 determines that the train 13 is entering the track 11-b.

As described above, the railroad management system 2 according to the fifth embodiment executes the process of track sensing in the track sensing unit 264 of the communication terminal 26 while collecting the distance estimation results 29 in the database 245 of the communication terminal 26, whereby the first UWB terminal 22 does not need to perform the process of distance estimation and the process of track sensing. In the fifth embodiment, the first UWB terminal 22 and the communication terminal 26 are connected by wireless communication, but the first UWB terminal 22 and the communication terminal 26 may be connected by wire.

Sixth Embodiment

The railroad management system 2 according to the sixth embodiment includes a communication terminal 26A instead of the communication terminal 26 according to the fifth embodiment. FIG. 14 is a diagram illustrating a functional configuration of the communication terminal 26A according to the sixth embodiment. Hereinafter, differences from the fifth embodiment will be mainly described.

The communication terminal 26A includes the communication antenna 261 for wireless communication, the transmission signal generation unit 262, the data signal demodulation unit 263, the track sensing unit 264, a data server 265A, and a stop instruction unit 266.

The data server 265A stores the distance estimation result 29, and stores in advance information indicating the track 11 that each train 13 is scheduled to enter. For example, the data server 265A stores information in which the identifier of the train 13 is associated with the track 11 that the train 13 is scheduled to enter. The stop instruction unit 266 collates the information of the track 11 that the train 13 is entering sensed by the track sensing unit 264 with the information indicating the track 11 that the train 13 is scheduled to enter stored in the data server 265A, generates a stop instruction for the train 13 when the sensed track 11 does not match the track 11 that the train 13 is scheduled to enter, and outputs the stop instruction to the transmission signal generation unit 262.

FIG. 15 is a sequence diagram illustrating a communication sequence of the railroad management system 2 according to the sixth embodiment. Because steps S40 to S45 in the communication sequence are the same as those in FIG. 13, the description thereof is omitted. Upon receiving the distance estimation results 29-a to 29-d, the communication terminal 26A saves the received distance estimation results 29-a to 29-d in the data server 265A, and performs the process of track sensing at the track sensing unit 264 based on the distance estimation results 29-a to 29-d. The stop instruction unit 266 collates the track 11 sensed by the track sensing unit 264 with the track 11 that the train 13 is scheduled to enter, indicated by the information stored in advance in the data server 265A. When the track 11 sensed by the track sensing unit 264 is different from the track 11 that the train 13 is scheduled to enter, the stop instruction unit 266 generates a stop instruction 30 and transmits the stop instruction 30 to the first UWB terminal 22-b-1 (step S46). Upon receiving the stop instruction 30, the first UWB terminal 22-b-1 transfers the received stop instruction 30 to the second UWB terminal 24-b installed on the train 13 (step S47). The train 13 stops based on the stop instruction 30.

As described above, the railroad management system 2 according to the sixth embodiment can confirm whether the train 13 is operating as scheduled by comparing the sensed track 11 with the track 11 that the train 13 is scheduled to enter stored in the data server 265A. In addition, in the event that the train 13 is entering an unscheduled track 11, it is possible to stop the train 13 so that the train 13 can operate more safely.

Seventh Embodiment

FIG. 16 is a diagram illustrating a configuration of a railroad management system 3 according to the seventh embodiment. The railroad management system 3 includes the four tracks 11-a to 11-d, the first UWB terminals 12-a-1 to 12-d-1 and 12-a-2 to 12-d-2 provided corresponding to the tracks 11-a to 11-d as first wireless terminals installed at the ends of the platforms of the corresponding tracks, the train 13, second UWB terminals 34-a and 34-b installed at the ends of the train 13 as second wireless terminals that perform ultra-wide band wireless communication with the first wireless terminals, and platform gates 31-a to 31-d installed on the tracks 11-a to 11-d, respectively.

The platform gate 31 has a plurality of platform doors. Each platform door is provided at a position corresponding to a door of the train 13. The platform door is opened when the door of the train 13 standing at the correct position is opened, and passengers can get off the train 13 on the platform. The term “corresponding” regarding the platform doors and the doors of the train 13 means that the platform doors and the doors of the train 13 corresponding to each other overlap in the longitudinal direction of the platform when the train 13 is standing at the correct position. In addition, the platform gate 31 is equipped with a sensor 43 (not illustrated) that determines whether there is a person around the platform doors. Note that the number of platform doors provided on the platform gate 31 does not necessarily coincide with the number of doors provided on the train 13. For example, the length of the train 13 that stops at the platform may be different for each train 13, in which case the platform gate 31 is provided in accordance with the length of the longest train 13, and when the train 13 having a short length is standing, some of the platform doors are kept closed while the doors of the train 13 are open. Alternatively, door positions may be different for each train 13, in which case the platform doors to be opened are changed in accordance with a type of the train 13.

FIG. 17 is a diagram illustrating a functional configuration of the second UWB terminal 34 illustrated in FIG. 16. The second UWB terminal 34 includes the preamble signal generation unit 121, the data signal generation unit 122, the signal detection unit 123, the reception timing estimation unit 124, the data signal demodulation unit 125, the UWB antenna 126, the distance estimation unit 141, the track sensing unit 142, a stop determination unit 341, a train length estimation unit 342, and a door opening/closing control unit 343. Hereinafter, differences from the second UWB terminal 14 illustrated in FIG. 3 will be mainly described.

The distance estimation unit 141 outputs the estimation result of the distance to the track sensing unit 142 and the stop determination unit 341. The stop determination unit 341 determines whether the train 13 has stopped based on the estimation result of the distance output by the distance estimation unit 141. For example, when the estimation result from the distance estimation unit 141 stops changing, the stop determination unit 341 can determine that the train 13 has stopped. Upon determining that the train 13 has stopped, the stop determination unit 341 notifies the train length estimation unit 342 that the train 13 has stopped, and outputs the estimation result from the distance estimation unit 141 to the train length estimation unit 342.

After the stop determination unit 341 determines that the train 13 has stopped, the train length estimation unit 342 estimates the length of the train 13 based on the estimation result from the distance estimation unit 141. For example, when the train 13 is standing on the front side in the traveling direction of FIG. 16, the train length estimation unit 342 can estimate the length of the train 13 based on the distance between the second UWB terminal 34-a installed on the rear side of the train 13 in the traveling direction and the first UWB terminal 12-b-1 installed at the rear-side end of the platform in the traveling direction. When the train 13 is standing on the rear side in the traveling direction, the train length estimation unit 342 can estimate the length of the train 13 based on the distance between the second UWB terminal 34-b installed on the front side of the train 13 in the traveling direction and the first UWB terminal 12-b-2 installed at the front-side end of the platform in the traveling direction. Alternatively, the estimation results of the distance may be transmitted and received between the second UWB terminals 34-a and 34-b installed at the opposite ends of the train 13, in which case the train length estimation unit 342 may estimate the length of the train 13 based on the distance between the first UWB terminal 12-b-1 and the second UWB terminal 34-a and the distance between the first UWB terminal 12-b-2 and the second UWB terminal 34-b. The train length estimation unit 342 outputs the estimation result of the length of the train 13 to the door opening/closing control unit 343.

The door opening/closing control unit 343 can give an instruction to open or close the platform doors of the platform gate 31 based on the determination result from the stop determination unit 341. Specifically, after the stop determination unit 341 determines that the train 13 has stopped, the door opening/closing control unit 343 can give an instruction to open or close the platform doors. The door opening/closing control unit 343 gives an instruction to open or close the platform doors in accordance with the opening/closing instruction for the doors of the train 13. The door opening/closing control unit 343 may determine the timing to open or close the platform doors based on the sensing result from the sensor 43 provided on the platform gate 31. In addition, the door opening/closing control unit 343 can also determine the platform doors to be opened and closed among a plurality of platform doors of the platform gate 31 based on the length of the train 13 estimated by the train length estimation unit 342. For example, when the number of doors of the train 13 and the number of platform doors of the platform gate 31 are considered to coincide based on the estimation result of the length of the train 13, the door opening/closing control unit 343 can open and close all the platform doors. When the number of doors of the train 13 is considered to be smaller than the number of platform doors of the platform gate 31 based on the estimation result of the length of the train 13, the door opening/closing control unit 343 can open and close some of the platform doors provided on the platform gate 31. The door opening/closing control unit 343 holds in advance information indicating the correspondence relationship between the length of the train 13 and the platform doors to be opened and closed, and can determine the platform doors to be opened and closed based on the correspondence relationship.

FIG. 18 is a sequence diagram illustrating a communication sequence of the railroad management system 3 according to the seventh embodiment. Because steps S10 to S14 are similar to those in FIG. 4, a detailed description thereof is omitted here by replacing the second UWB terminal 14-b in the description of FIG. 4 with the second UWB terminal 34-b. After the second UWB terminal 34-b transmits the track sensing signal 18, the process of estimating the distance is repeated between the first UWB terminals 12-b-1 and 12-b-2 installed on the platform of the sensed track 11 and the second UWB terminals 34-a and 34-b. Specifically, the distance estimation unit 141 of the second UWB terminal 34-a installed on the inbound side of the train 13 estimates the distance to the first UWB terminal 12-b-1 installed on the inbound side of the platform, and the distance estimation unit 141 of the second UWB terminal 34-b installed on the outbound side of the train 13 estimates the distance to the first UWB terminal 12-b-2 installed on the outbound side of the platform (step S50).

The stop determination unit 341 of each of the second UWB terminals 34-a and 34-b determines whether the train 13 has stopped based on the estimation result of the distance. In response to a determination that the train 13 has stopped, the door opening/closing control unit 343 of each of the second UWB terminals 34-a and 34-b transmits an opening/closing instruction 35 for the platform doors to the platform gate 31 in accordance with the opening/closing instruction for the train 13 (step S51). As described above, the door opening/closing control unit 343 may determine the platform doors to be opened and closed among a plurality of platform doors of the platform gate 31 in accordance with the length of the train 13 estimated by the train length estimation unit 342. In this case, the process of estimating the length of the train 13 in the train length estimation unit 342 is interposed between step S50 and step S51, and the door opening/closing control unit 343 transmits the opening/closing instruction 35 designating the platform doors to be opened and closed. Alternatively, the process of determining the platform doors to be opened and closed may be performed in the platform gate 31, in which case the door opening/closing control unit 343 may transmit to the platform gate 31 the opening/closing instruction 35 including information indicating the length of the train 13 estimated by the train length estimation unit 342.

As described above, the railroad management system 3 according to the seventh embodiment can open and close the platform doors of the platform gate 31 in conjunction with the opening and closing of the doors of the train 13 after sensing the track 11 that the train 13 is entering. In addition, the length of the train 13 can be estimated from the estimation result of the distance between the first UWB terminal 12 and the second UWB terminal 34, and the platform doors to be opened and closed can be determined from among a plurality of platform doors of the platform gate 31. In this case, when the number of doors is different for each train 13 and there is no door of the train 13 corresponding to a platform door, the platform door having no corresponding door can be kept closed. Therefore, even when the number of doors is different for each train 13, it is possible to prevent the passengers from falling onto the railroad track, and to enhance the safety of the railroad management system 3.

Eighth Embodiment

FIG. 19 is a diagram illustrating a configuration of a railroad management system 4 according to the eighth embodiment. In addition to the components of the railroad management system 3 illustrated in FIG. 16, the railroad management system 4 further includes a plurality of third UWB terminals 41, which are third wireless terminals installed on the platform gate 31 corresponding to the platform doors, and a plurality of fourth UWB terminals 42, which are fourth wireless terminals installed on the train 13 corresponding to the doors of the train 13. For simplicity, FIG. 19 illustrates a part of the railroad management system 4 after the entry of the train 13 to the track 11-b as viewed from the platform side. In addition, the sensor 43 (not illustrated) that determines whether there is a person around is installed near each platform door of the platform gate 31.

The third UWB terminal 41 has, for example, a configuration similar to that of the first UWB terminal 12 illustrated in FIG. 2. The fourth UWB terminal 42 has, for example, a configuration similar to that of the second UWB terminal 14 illustrated in FIG. 3.

After the train 13 stops, the railroad management system 4 controls the opening and closing of the platform doors and the doors of the train 13 based on the estimation result of the distance between the third UWB terminal 41 and the fourth UWB terminal 42. When the distance between the third UWB terminal 41 and the fourth UWB terminal 42 is equal to or less than the threshold, it can be determined that the door of the train 13 is present at a certain distance from the platform door, and when the door of the train 13 corresponding to the platform door is present, the platform door is opened. When it is determined that there is no door of the train 13 corresponding to the platform door, the platform door is kept closed.

FIG. 20 is a sequence diagram illustrating a communication sequence of the railroad management system 4 according to the eighth embodiment. Note that FIG. 20 illustrates one third UWB terminal 41, one fourth UWB terminal 42 corresponding to the door of the train 13 at the position corresponding to the platform door in the vicinity of the third UWB terminal 41 installed, and one sensor 43 installed corresponding to the same platform door as the third UWB terminal 41. In practice, however, the railroad management system 4 includes a plurality of third UWB terminals 41, a plurality of fourth UWB terminals 42, and a plurality of sensors 43.

Because steps S10 to S50 are similar to those in FIG. 18, the description thereof is omitted here. In step S50, while the estimation of the distance between the first UWB terminal 12 and the second UWB terminal 34 is repeated, the second UWB terminal 34 determines whether the train 13 has stopped based on the estimation result of the distance. Upon determining that the train 13 has stopped, the second UWB terminal 34-a transmits a distance estimation instruction 36 to each of the plurality of fourth UWB terminals 42 installed on the train 13 (step S52).

Upon receiving the distance estimation instruction 36, the fourth UWB terminal 42 estimates the distance between the third UWB terminal 41 and the fourth UWB terminal 42 (step S53). At this time, if the fourth UWB terminal 42 can communicate with a plurality of third UWB terminals 41, interference occurs. Therefore, the preamble signal for use in signal detection between the third UWB terminal 41 and the fourth UWB terminal 42 is different for each combination of the third UWB terminal 41 and the fourth UWB terminal 42. Here, the combination of the third UWB terminal 41 and the fourth UWB terminal 42 refers to the combination of the third UWB terminal 41 and the fourth UWB terminal 42 respectively corresponding to the door of the train 13 and the platform door overlapping in the longitudinal direction of the platform when the train 13 is standing at the correct position on the platform.

The fourth UWB terminal 42 receives a sensor signal 37 from the sensor 43 (step S54). The fourth UWB terminal 42 determines whether the estimation result of the distance in step S53 is equal to or less than a predetermined threshold, and in response to determining that the estimation result is equal to or less than the threshold, transmits an opening/closing instruction 38 for the platform door corresponding to the fourth UWB terminal 42 to the third UWB terminal 41 (step S55). Upon receiving the opening/closing instruction 38, the third UWB terminal 41 transfers the received opening/closing instruction 38 to the platform gate 31 (step S56). Note that the fourth UWB terminal 42 gives an instruction to open or close each door of the train 13 in accordance with the opening/closing instruction 38 for the platform door. At this time, when the fourth UWB terminal 42 confirms that there is no person moving around using the sensor signal 37 from the sensor 43, the fourth UWB terminal 42 can give an instruction to open or close the platform door and the door of the train 13.

As described above, the railroad management system 4 according to the eighth embodiment further includes the third UWB terminal 41 corresponding to each platform door of the platform gate 31 and the fourth UWB terminal 42 corresponding to each door of the train 13, and the opening and closing of the platform doors and the doors of the train 13 are controlled for each door based on the estimation result of the distance between the third UWB terminal 41 and the fourth UWB terminal 42. Since the third UWB terminal 41 is installed near the platform door of the platform gate 31 and the fourth UWB terminal 42 is installed near each door of the train 13, the distance between the third UWB terminal 41 and the fourth UWB terminal 42 can be considered the distance between the platform door and the door of the train 13. Only when the distance between the platform door and the door of the train 13 is equal to or less than the threshold, the platform door and the door of the train 13 are opened and closed, and when the distance exceeds the threshold, the platform door and the door of the train 13 are not opened and closed, which is advantageous in cases where, for example, the train 13 is operated by automatic operation without the driver and the surrounding situation cannot be visually confirmed, because the opening and closing of the doors of the train 13 can be implemented in conjunction with the platform gate 31.

Ninth Embodiment

FIG. 21 is a diagram illustrating a configuration of a railroad management system 5 according to the ninth embodiment. In addition to the components of the railroad management system 2 illustrated in FIG. 9, the railroad management system 5 further includes the platform gate 31, a ground wireless device 51 installed on the platform gate 31, and an on-board wireless device 53 installed on the train 13. In addition, the railroad management system 5 includes a communication terminal 52 instead of the communication terminal 26 of the railroad management system 2. For simplicity, FIG. 21 illustrates a part of the railroad management system 5, specifically, a part of the track 11-b that the train 13 is entering. The ground wireless device 51 and the on-board wireless device 53 can each wirelessly connect to the communication terminal 52. In addition, the ground wireless device 51 can control the platform gate 31, and can open and close the platform doors of the platform gate 31 in accordance with an instruction from the communication terminal 52. The on-board wireless device 53 can open and close the doors of the train 13 in accordance with an instruction from the communication terminal 52.

FIG. 22 is a diagram illustrating a functional configuration of the communication terminal 52 illustrated in FIG. 21. The communication terminal 52 includes the communication antenna 261 for wireless communication, the transmission signal generation unit 262, the data signal demodulation unit 263, the track sensing unit 264, the data server 265, the stop determination unit 341, the train length estimation unit 342, and a door opening instruction unit 521. The communication terminal 52 wirelessly connects to the first UWB terminals 22, and collects the estimation result of the distance to the second UWB terminal 24 estimated by each of the plurality of first UWB terminals 22. Because the communication antenna 261, the transmission signal generation unit 262, the data signal demodulation unit 263, the track sensing unit 264, and the data server 265 are similar to those of the communication terminal 26 illustrated in FIG. 12, a detailed description thereof is omitted here. Because the stop determination unit 341 and the train length estimation unit 342 are similar to those of the second UWB terminal 34 illustrated in FIG. 17, a detailed description thereof is omitted here. Hereinafter, differences from the communication terminal 26 illustrated in FIG. 12 will be mainly described.

The data signal demodulation unit 263 outputs the demodulated data to the stop determination unit 341 in addition to the track sensing unit 264. The stop determination unit 341 determines whether the train 13 has stopped based on the estimation result of the distance between the first UWB terminal 22 and the second UWB terminal 24 included in the demodulated data. The stop determination unit 341 collects the estimation result of the distance calculated by each of the first UWB terminals 22, and determines whether the train 13 has stopped based on the collected estimation results. The criterion for the stop determination unit 341 to determine whether the train 13 has stopped is similar to that in the seventh embodiment.

The train length estimation unit 342 estimates the length of the train 13 based on the estimation result of the distance between the first UWB terminal 22 and the second UWB terminal 24. The method for the train length estimation unit 342 to estimate the length of the train 13 is similar to that in the seventh embodiment. The train length estimation unit 342 outputs the estimation result of the length of the train 13 to the door opening instruction unit 521.

The door opening instruction unit 521 generates an instruction for opening the platform doors of the platform gate 31 and the doors of the train 13 based on the determination result from the stop determination unit 341 and the estimation result from the train length estimation unit 342, and transmits a signal including the generated instruction to both the ground wireless device 51 and the on-board wireless device 53. At this time, the door opening instruction unit 521 can determine the timing to open the doors based on the determination result from the stop determination unit 341, and determine the doors to be opened among the plurality of doors based on the estimation result of the length of the train 13. The door opening instruction unit 521 can perform control to allow or not allow opening for each door, and can keep the platform door that does not correspond to any door of the train 13 closed.

FIG. 23 is a sequence diagram illustrating a communication sequence of the railroad management system 5 according to the ninth embodiment. Because steps S40 to S45 are similar to those in FIG. 13, a detailed description thereof is omitted by replacing the communication terminal 26 with the communication terminal 52.

Once the track 11 that the train 13 is entering is sensed based on the distance estimation result 29 collected from each of the first UWB terminals 22, the stop determination unit 341 determines whether the train 13 has stopped based on the collected distance estimation result 29. In response to a determination that the train 13 has stopped, the train length estimation unit 342 estimates the length of the train 13 based on the distance estimation result 29. The train length estimation unit 342 outputs the estimation result of the length of the train 13 to the door opening instruction unit 521.

After the stop determination unit 341 determines that the train 13 has stopped, the door opening instruction unit 521 transmits a door opening instruction 55 for opening the doors of the train 13 and the platform doors of the platform gate 31 to both the ground wireless device 51 and the on-board wireless device 53 (step S60). At this time, the communication terminal 52 selects the doors to be opened based on the estimation result from the train length estimation unit 342. When the number of platform doors of the platform gate 31 is larger than the number of doors of the train 13, the door opening instruction unit 521 opens some of the plurality of platform doors of the platform gate 31. For example, given the premise that the train 13 is standing on the outbound side of the platform, the door opening instruction unit 521 determines the number of platform doors to be kept closed based on the estimation result of the length of the train 13, and keeps a determined number of platform doors closed from the inbound side.

As described above, the railroad management system 5 according to the ninth embodiment includes the ground wireless device 51 installed on the platform gate 31, the on-board wireless device 53 installed on the train 13, and the communication terminal 52 capable of communicating with the first UWB terminal 22. The communication terminal 52 collects the estimation result of the distance between the first UWB terminal 22 and the second UWB terminal 24 from the first UWB terminal 22, determines whether the train 13 has stopped based on the collected estimation result, estimates the length of the train 13, and gives an instruction to open the doors of the train 13 and the platform doors. The ground wireless device 51 opens the platform doors in accordance with the instruction from the communication terminal 52, and the on-board wireless device 53 opens the doors of the train 13 in accordance with the instruction from the communication terminal 52. The railroad management system 5 with the above-described configuration is advantageous in cases where, for example, the train 13 is operated by automatic operation without the driver and the surrounding situation cannot be visually confirmed, because the doors of the train 13 can be opened in conjunction with the platform gate 31. In the ninth embodiment, the communication terminal 52 controls only the opening of the doors, but the communication terminal 52 may also give an instruction to close the doors.

Tenth Embodiment

FIG. 24 is a diagram illustrating a configuration of a railroad management system 6 according to the tenth embodiment. In addition to the components of the railroad management system 3 illustrated in FIG. 16, the railroad management system 6 includes a ground wireless device 61 installed on the platform gate 31 and an on-board wireless device 63 installed on the train 13. For simplicity, FIG. 24 illustrates a part of the railroad management system 6, specifically, a part of the track 11-b that the train 13 is entering. In addition, the sensor 43 (not illustrated) that determines whether there is a person around is installed near each platform door of the platform gate 31. The ground wireless device 61 can open and close the platform doors of the platform gate 31 and can acquire sensing results from the sensor 43 installed on the platform gate 31. The on-board wireless device 63 can communicate with the second UWB terminal 34 and can open and close the doors of the train 13.

FIG. 25 is a sequence diagram illustrating a communication sequence of the railroad management system 6 according to the tenth embodiment. Because steps S10 to S50 are similar to those in FIG. 18, a detailed description thereof is omitted here.

Once the distance between the first UWB terminal 12-b-1 and the second UWB terminal 34-a and the distance between the first UWB terminal 12-b-2 and the second UWB terminal 34-b are estimated in step S50, the second UWB terminal 34 determines whether the train 13 has stopped based on the estimation result. In response to a determination that the train 13 has stopped, the door opening/closing control unit 343 of the second UWB terminal 34 transmits stop information 54 for instructing the on-board wireless device 63 to open the platform doors of the platform gate 31 in conjunction with giving the instruction to open the doors of the train 13 (step S61).

Upon receiving the stop information 54 from each of the second UWB terminals 34-a and 34-b, the on-board wireless device 63 transmits the door opening instruction 55 to open the platform doors of the platform gate 31 to the ground wireless device 61 in accordance with the instruction to open the doors of the train 13 (step S62). The ground wireless device 61 opens the platform doors of the platform gate 31 in response to the door opening instruction 55. After opening the platform doors, the ground wireless device 61 transmits a door closing instruction 56 to close the doors of the train 13 to the on-board wireless device 63 at the timing when the safety of the platform side is ensured with no person moving around based on the sensor signal from the sensor 43 (step S63).

As described above, the railroad management system 6 according to the tenth embodiment includes the ground wireless device 61 installed on the platform gate 31 including a plurality of platform doors, and the on-board wireless device 63 installed on the train 13. The on-board wireless device 63 gives an instruction to open the doors of the train 13 in accordance with the stop timing of the train 13 provided from the second UWB terminal 34, and transmits the door opening instruction 55 to open the platform doors to the ground wireless device 61. In addition, the ground wireless device 61 opens the platform doors in response to the door opening instruction 55, thereafter gives an instruction to close the platform doors, and transmits the door closing instruction 56 to close the doors of the train 13 to the on-board wireless device 63. Similarly to the eighth and ninth embodiments, the railroad management system 6 with the above-described configuration is advantageous in cases where, for example, the train 13 is operated by automatic operation without the driver and the surrounding situation cannot be visually confirmed, because the doors of the train 13 can be opened and closed in conjunction with the platform gate 31.

Eleventh Embodiment

FIG. 26 is a diagram illustrating a configuration of a railroad management system 7 according to the eleventh embodiment. In addition to the components of the railroad management system 1 illustrated in FIG. 1, the railroad management system 7 includes a plurality of monitoring cameras 71 that capture each platform, an on-board wireless device 72 installed on the train 13, a camera wireless device 73 connected to the monitoring camera 71, and a data server 74 that saves videos from the monitoring camera 71. The on-board wireless device 72 is connected to the second UWB terminal 14 installed on the train 13. For simplicity, the railroad management system 7 includes one monitoring camera 71 on each platform, but a plurality of monitoring cameras 71 may be installed on one platform. Although the railroad management system 7 includes one camera wireless device 73 and one camera wireless device 73 is connected to the plurality of monitoring cameras 71, the railroad management system 7 may include a plurality of camera wireless devices 73. For example, the railroad management system 7 may include the camera wireless device 73 installed for each platform, or may include a plurality of camera wireless devices 73 on one platform.

FIG. 27 is a diagram illustrating a functional configuration of the on-board wireless device 72 illustrated in FIG. 26. The on-board wireless device 72 includes a communication antenna 721, a transmission signal generation unit 722, and a reception signal processing unit 723. The communication antenna 721 wirelessly connects to other devices, transmits the transmission signal generated by the transmission signal generation unit 722, and outputs the reception signal to the reception signal processing unit 723. The transmission signal generation unit 722 generates the transmission signal to be wirelessly transmitted and outputs the transmission signal to the communication antenna 721. The reception signal processing unit 723 processes the reception signal and extracts data included in the reception signal.

FIG. 28 is a diagram illustrating a functional configuration of the camera wireless device 73 illustrated in FIG. 26. The camera wireless device 73 includes the communication antenna 721, the transmission signal generation unit 722, the reception signal processing unit 723, a video management unit 731, and a memory unit 732 that stores a part of the received data.

The transmission signal generation unit 722 generates the transmission signal to be wirelessly transmitted and causes the communication antenna 721 to output the transmission signal. The reception signal processing unit 723 processes the reception signal and extracts data included in the reception signal. The reception signal processing unit 723 outputs the data extracted from the reception signal to the video management unit 731. Once the reception signal processing unit 723 outputs the monitoring video captured by the monitoring camera 71, the video management unit 731 stores the monitoring video in the memory unit 732 and transmits the monitoring video to the data server 74. In addition, the video management unit 731 is given a notification of the track 11 that the train 13 has entered, then selects the monitoring video to be transmitted to the on-board wireless device 72 from among the monitoring videos stored in the memory unit 732 based on the track 11 indicated by the notification, and starts a process of continuously transmitting the selected monitoring video to the on-board wireless device 72. Specifically, the video management unit 731 selects the video of the monitoring camera 71 capturing the platform related to the track 11 indicated by the notification among the plurality of monitoring cameras 71. The platform related to the track 11 indicated by the notification may be the platform on which the track 11 indicated by the notification is provided, or may be the platform at which the train 13 of the route 15 to which the track 11 indicated by the notification belongs stops. In addition, the video management unit 731 ends the transmission of the video at the timing when the wireless communication link between the on-board wireless device 72 and the camera wireless device 73 is disconnected.

FIG. 29 is a sequence diagram illustrating a communication sequence of the railroad management system 7 according to the eleventh embodiment. Because steps S10 to S13 are similar to those in FIG. 4, a detailed description thereof is omitted here. The monitoring camera 71 always captures the platform and transmits the captured monitoring video to the camera wireless device 73. The camera wireless device 73 stores the received monitoring video in the internal memory unit 732 and transmits the received monitoring video to the data server 74. The data server 74 saves the received monitoring video (step S70). When the capacity of the memory unit 732 of the camera wireless device 73 becomes full, the oldest monitoring video is overwritten with the latest monitoring video. Therefore, the memory unit 732 always stores a predetermined amount of latest monitoring video that depends on its capacity.

Upon sensing the track 11 that the train 13 is entering, the second UWB terminal 14-b transmits the track sensing signal 18 indicating the sensed track to the on-board wireless device 72 (step S71). Upon receiving the track sensing signal 18, the on-board wireless device 72 transfers the received track sensing signal 18 to the camera wireless device 73 (step S72). Upon receiving the track sensing signal 18, the camera wireless device 73 establishes a wireless link with the on-board wireless device 72 (step S73), and selects the monitoring video to be transmitted to the on-board wireless device 72 based on the received track sensing signal 18. The camera wireless device 73 starts continuous transmission of the selected monitoring video from the memory unit 732 to the on-board wireless device 72 (step S74). Thereafter, when the communication link with the on-board wireless device 72 is disconnected, the camera wireless device 73 stops transmitting the monitoring video.

As described above, the railroad management system 7 according to the eleventh embodiment includes a plurality of monitoring cameras that capture the platforms, the on-board wireless device 72 provided on the train 13, and the camera wireless device 73, and the camera wireless device 73 selects a monitoring video from among the monitoring videos captured by the plurality of monitoring cameras 71 based on the track 11-b that the train 13 is entering, and transmits the selected monitoring video to the on-board wireless device 72. Specifically, the camera wireless device 73 selects the monitoring camera 71 that captures the platform of the track 11-b sensed by the track sensing unit 142, and transmits the monitoring video of the selected monitoring camera 71 to the on-board wireless device 72. Because the railroad management system 7 has the above-described configuration, the on-board wireless device 72 installed on the train 13 can acquire the latest monitoring video of the platform of the track 11-b that the train 13 is entering. In addition, the monitoring video may be used for safety confirmation by the station staff and crew. For example, by displaying this monitoring video on a display unit provided on the driver's seat of the train 13, platforms, and the like, the driver can operate the train 13 while checking the state of the platforms shown in the monitoring video, or can open and close the doors while checking the video of the doors and their surroundings, so that the train 13 can be operated safely. In addition, in cases where the train 13 is in automatic operation, the safety of the railroad management system 7 can be enhanced by using this monitoring video for controlling the automatic operation.

Twelfth Embodiment

The configuration of the railroad management system 7 according to the twelfth embodiment is similar to that in the eleventh embodiment illustrated in FIG. 26. Hereinafter, differences from the eleventh embodiment will be mainly described.

FIG. 30 is a sequence diagram illustrating a communication sequence of the railroad management system 7 according to the twelfth embodiment. Upon sensing the track 11-b that the train 13 is entering after receiving the response signals 17-a to 17-d in step S13, the second UWB terminal 14-b transmits the track sensing signal 18 indicating the sensed track 11-b to the first UWB terminal 12-b-1 (step S14).

Upon receiving the track sensing signal 18 from the second UWB terminal 14-b, the first UWB terminal 12-b-1 transfers the received track sensing signal 18 to the camera wireless device 73 (step S75). After the camera wireless device 73 receives the track sensing signal 18, steps S73 and S74 are similar to those in the eleventh embodiment, and thus a detailed description thereof is omitted here.

The second UWB terminal 14-b in the eleventh embodiment transmits the track sensing signal 18 to the camera wireless device 73 via the on-board wireless device 72, whereas the second UWB terminal 14-b in the twelfth embodiment transmits the track sensing signal 18 to the camera wireless device 73 via the first UWB terminal 12-b-1 installed on the track 11-b sensed by the track sensing unit 142. Even with the above-described configuration, the camera wireless device 73 can find the track 11-b that the train 13 is entering. Therefore, similarly to the eleventh embodiment, the on-board wireless device 72 installed on the train 13 can acquire the latest monitoring video of the platform of the track 11-b that the train 13 is entering.

Thirteenth Embodiment

FIG. 31 is a diagram illustrating a configuration of a railroad management system 8 according to the thirteenth embodiment. The railroad management system 8 includes a camera wireless device 83 instead of the camera wireless device 73 of the railroad management system 7 illustrated in FIG. 26, and includes a core server 84 in addition to the components of the railroad management system 7. The core server 84 can communicate with the camera wireless device 83 and the data server 74. In the railroad management system 7, the camera wireless device 73 selects the monitoring video to be transmitted to the on-board wireless device 72 and transmits the monitoring video, whereas in the railroad management system 8, the core server 84 selects the monitoring video to be transmitted to the on-board wireless device 72 and transmits the monitoring video.

FIG. 32 is a diagram illustrating a functional configuration of the camera wireless device 83 illustrated in FIG. 31. The camera wireless device 83 includes the communication antenna 721, the transmission signal generation unit 722, and the reception signal processing unit 723. The functions of the communication antenna 721, the transmission signal generation unit 722, and the reception signal processing unit 723 are similar to those of the respective functional units of the on-board wireless device 72 illustrated in FIG. 27, and thus a detailed description thereof is omitted here.

FIG. 33 is a diagram illustrating a functional configuration of the core server 84 illustrated in FIG. 31. The core server 84 includes a video processing unit 841, an edge server 842, and a memory unit 843. The video processing unit 841 processes data of the monitoring video captured by the monitoring camera 71. The video processing unit 841 stores the processed monitoring video in the memory unit 843. The edge server 842 has a function of selecting the monitoring video to be transmitted to the on-board wireless device 72 of the train 13. In addition, the edge server 842 transmits the monitoring video processed by the video processing unit 841 to the data server 74. Therefore, the data server 74 stores the monitoring video subjected to the processing in the core server 84. The memory unit 843 stores the latest monitoring video.

FIG. 34 is a sequence diagram illustrating a communication sequence of the railroad management system 8 according to the thirteenth embodiment. Because steps S10 to S13 are similar to those in FIG. 4, a detailed description thereof is omitted here.

The monitoring video captured by the monitoring camera 71 is transmitted to the core server 84 via the camera wireless device 83. After being subjected to the video processing in the core server 84, the monitoring video is stored in the memory unit 843 of the core server 84, transferred to the data server 74, and accumulated in the data server 74 (step S80). Thereafter, before track sensing, a wireless link is established between the on-board wireless device 72 and the camera wireless device 83 (step S81).

Upon sensing the track 11-b that the train 13 is entering based on the response signals 17-a to 17-d, the second UWB terminal 14-b transmits the track sensing signal 18 indicating the sensed track 11-b to the on-board wireless device 72 (step S82). Upon receiving the track sensing signal 18, the on-board wireless device 72 transfers the received track sensing signal 18 to the camera wireless device 83 (step S83). Upon receiving the track sensing signal 18, the camera wireless device 83 transfers the received track sensing signal 18 to the core server 84 (step S84).

Upon receiving the track sensing signal 18, the core server 84 selects the monitoring video to be transmitted to the on-board wireless device 72 of the train 13 from among the monitoring videos stored in the memory unit 843 based on the received track sensing signal 18, and continuously transmits the selected monitoring video to the on-board wireless device 72 (step S85). Here, the monitoring video of the monitoring camera 71 installed on the route 15-a is selected.

On the other hand, after the track 11-b that the train 13 is entering is sensed, the second UWB terminal 14 estimates the distance to the first UWB terminal 12 (step S86). Specifically, the second UWB terminal 14-a estimates the distance to the first UWB terminal 12-b-1, and the second UWB terminal 14-b estimates the distance to the first UWB terminal 12-b-2.

When the estimation result of the distance satisfies a predetermined condition, the second UWB terminal 14-b determines that the train 13 has left the platform and transmits a video stop instruction 57 to the core server 84 (step S87). For example, the second UWB terminal 14-b can transmit the video stop instruction 57 when any estimation result exceeds a predetermined threshold. Upon receiving the video stop instruction 57, the core server 84 stops the transmission of the monitoring video.

As described above, in the railroad management system 8 according to the thirteenth embodiment, video processing that requires a heavy processing load can be aggregated in the core server 84, and as in the eleventh and twelfth embodiments, the on-board wireless device 72 installed on the train 13 can acquire the latest monitoring video of the platform of the track 11-b that the train 13 is entering.

In addition, in the railroad management system 8, the second UWB terminal 14 can instruct the core server 84 to stop the transmission of the monitoring video based on the estimation result of the distance to the first UWB terminal 12. As a result, as the train 13 departs and leaves the platform, the transmission of the monitoring video can be automatically stopped.

Next, a hardware configuration of the first UWB terminals 12 and 22, the second UWB terminals 14, 24, and 34, the third UWB terminal 41, the fourth UWB terminal 42, the communication terminals 26, 26A, and 52, the ground wireless devices 51 and 61, the on-board wireless devices 53, 63, and 72, the camera wireless devices 73 and 83, the data server 74, and the core server 84 according to the first to thirteenth embodiments will be described. The functional units included in the first UWB terminals 12 and 22, the second UWB terminals 14, 24, and 34, the third UWB terminal 41, the fourth UWB terminal 42, the communication terminals 26, 26A, and 52, the ground wireless devices 51 and 61, the on-board wireless devices 53, 63, and 72, the camera wireless devices 73 and 83, the data server 74, and the core server 84 are implemented by processing circuitry. The processing circuitry may be implemented by dedicated hardware or may be a control circuit using a central processing unit (CPU).

In a case where the above processing circuitry is implemented by dedicated hardware, the processing circuitry is implemented by processing circuitry 90 illustrated in FIG. 35. FIG. 35 is a diagram illustrating dedicated hardware for implementing the functions of the components of the railroad management systems 1 to 8 according to the first to thirteenth embodiments. The processing circuitry 90 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a combination thereof.

In a case where the above processing circuitry is implemented by a control circuit using a CPU, this control circuit is, for example, a control circuit 91 having the configuration illustrated in FIG. 36. FIG. 36 is a diagram illustrating an example of the control circuit 91 for implementing the functions of the components of the railroad management systems 1 to 8 according to the first to thirteenth embodiments. As illustrated in FIG. 36, the control circuit 91 includes a processor 92 and a memory 93. The processor 92 is a CPU, and is also called an arithmetic device, a microprocessor, a microcomputer, a digital signal processor (DSP), or the like. Examples of the memory 93 include a non-volatile or volatile semiconductor memory, a magnetic disk, a flexible disk, an optical disc, a compact disc, a mini disc, a digital versatile disc (DVD), and the like. Examples of non-volatile or volatile semiconductor memories include a random access memory (RAM), a read only memory (ROM), a flash memory, an erasable programmable ROM (EPROM), an electrically EPROM (EEPROM, registered trademark), and the like.

In a case where the above processing circuitry is implemented by the control circuit 91, the processor 92 reads and executes the program corresponding to the process of each component stored in the memory 93, thereby implementing the processing circuitry. The program may be provided via a communication path or may be provided by being stored in a storage medium. The memory 93 is also used as a temporary memory for each process executed by the processor 92.

The configurations described in the above-mentioned embodiments indicate examples. The embodiments can be combined with another well-known technique and with each other, and some of the configurations can be omitted or changed in a range not departing from the gist.

For example, in the railroad management systems 1 to 8 described in the first to thirteenth embodiments, the train 13 that travels on the route 15 from the urban area to the suburb in the first direction from the urban area to the suburb has been described, but the route 15 may be a loop line. In addition, the traveling direction of the train 13 may be the second direction opposite to the first direction, in which case before the train 13 stops, the distance is estimated between the second UWB terminal 14-a on the front side with respect to the train 13 traveling in the second direction that is the traveling direction among the two second UWB terminals 14 installed on the train 13 and the first UWB terminals 12-a-2 to 12-d-2 on the rear side with respect to the train 13 traveling in the second direction among the plurality of first UWB terminals 12 installed on the platforms, and the track 11 that the train 13 is entering is sensed based on the estimation result.

In addition, both the train 13 traveling in the first direction and the train 13 traveling in the second direction are allowed to enter the station illustrated in the first to thirteenth embodiments. However, for example, at a terminal station, the train 13 traveling in the first direction or the second direction may be allowed to enter the station, and the train 13 traveling in the other direction may not be allowed to enter the station. In this case, the railroad management systems 1 to 8 may include the first UWB terminals 12-a-1 to 12-d-1, and the first UWB terminals 12-a-2 to 12-d-2 may be omitted.

Note that a device including the track sensing unit 142 or 264 can also be referred to as a track sensing device. For example, the second UWB terminal 14 is a track sensing device in the first to fourth and eleventh to thirteenth embodiments, the communication terminals 26 and 26A are track sensing devices in the fifth and sixth embodiments, the second UWB terminal 34 is a track sensing device in the seventh, eighth, and tenth embodiments, and the communication terminal 52 is a track sensing device in the ninth embodiment.

The railroad management system according to the present disclosure can achieve the effect of improving the accuracy of sensing the track that the train is entering.

Claims

1. A railroad management system comprising: a plurality of first wireless terminals provided corresponding to a plurality of tracks, and each installed at an end of a platform of a corresponding track;a second wireless terminal installed at an end of a train, and configured to perform communication with the first wireless terminals using an ultra-wide band wireless signal;distance estimation circuitry to estimate a distance between each of the plurality of first wireless terminals and the second wireless terminal using the ultra-wide band wireless signal; andtrack sensing circuitry to sense a track that the train is entering based on an estimation result from the distance estimation circuitry, whereineach of the first wireless terminals transmits the ultra-wide band wireless signal including a signal detection signal different for each route of the corresponding track, and detects the ultra-wide band wireless signal received using the signal detection signal different for each route of the corresponding track,each of a plurality of the second wireless terminals transmits the ultra-wide band wireless signal including the signal detection signal different for each route of the train equipped with the second wireless terminal, and detects the ultra-wide band wireless signal received using the signal detection signal different for each route of the train equipped with the second wireless terminal, andthe first wireless terminal and the second wireless terminal use the signal detection signal in common when the route of the track corresponding to the first wireless terminal and the route of the train equipped with the second wireless terminal are identical.

2. The railroad management system according to claim 1, wherein the first wireless terminal is installed at each of both ends of the platform,the second wireless terminal is installed at each of both ends of the train,the train is capable of traveling in a first direction or a second direction opposite to the first direction, andamong the plurality of first wireless terminals, the first wireless terminal installed at an end on a front side with respect to the train traveling in the first direction uses a signal detection signal that is different from a signal detection signal of the first wireless terminal installed at an end on a rear side with respect to the train traveling in the first direction, and is identical to a signal detection signal of the second wireless terminal installed at an end on the front side among a plurality of the second wireless terminals, and the first wireless terminal installed at an end on the rear side among the plurality of first wireless terminals uses a signal detection signal that is identical to a signal detection signal of the second wireless terminal installed at an end on the rear side.

3. The railroad management system according to claim 1, wherein the second wireless terminal selects the first wireless terminal to be subjected to ranging from among the plurality of first wireless terminals based on an annunciation signal received from each of the plurality of first wireless terminals, andthe distance estimation circuitry estimates a distance between the first wireless terminal selected and the second wireless terminal, and does not estimate a distance between the first wireless terminal unselected and the second wireless terminal.

4. The railroad management system according to claim 1, wherein the second wireless terminal includes the distance estimation circuitry and the track sensing circuitry.

5. The railroad management system according to claim 1, wherein the first wireless terminal includes the distance estimation circuitry and the track sensing circuitry.

6. The railroad management system according to claim 1, wherein the first wireless terminal includes the distance estimation circuitry,the railroad management system further includes a communication terminal including the track sensing circuitry, andthe communication terminal collects the estimation result from the first wireless terminal, and senses a track that the train is entering based on the estimation result collected.

7. The railroad management system according to claim 1, further comprising: stop instruction circuitry to output a stop instruction for the train when a track that the train is scheduled to enter is different from a track sensed by the track sensing circuitry.

8. The railroad management system according to claim 1, further comprising: a platform gate including a plurality of platform doors;stop determination circuitry to determine whether the train has stopped based on the estimation result; anddoor opening/closing control circuitry to control opening and closing of the platform doors based on a determination result from the stop determination circuitry.

9. The railroad management system according to claim 8, further comprising: train length estimation circuitry to estimate a length of the train based on the estimation result, whereinthe door opening/closing control circuitry selects the platform doors to be opened and closed among the plurality of platform doors based on the length of the train estimated.

10. The railroad management system according to claim 1, further comprising: a platform gate including a plurality of platform doors;a third wireless terminal provided on the platform gate corresponding to each of the platform doors; anda fourth wireless terminal provided on the train corresponding to a door of the train, and configured to estimate a distance to the third wireless terminal using ultra-wide band wireless communication and give an opening/closing instruction to the platform doors based on an estimation result.

11. The railroad management system according to claim 10, wherein a plurality of the third wireless terminals are provided corresponding to each of the plurality of platform doors,a plurality of the fourth wireless terminals are provided corresponding to each of a plurality of the doors of the train, andthe fourth wireless terminals give an opening/closing instruction for each platform door when the estimation result is equal to or less than a threshold predetermined, and do not give an opening/closing instruction to the platform doors when the estimation result is larger than the threshold.

12. The railroad management system according to claim 1, further comprising: a platform gate including a plurality of platform doors; anda communication terminal to collect the estimation result, whereinthe first wireless terminal includes the distance estimation circuitry, andthe communication terminal includes:stop determination circuitry to determine whether the train has stopped based on the estimation result collected from the first wireless terminal; anddoor opening/closing control circuitry to control opening and closing of the platform doors and doors of the train based on the estimation result.

13. The railroad management system according to claim 12, further comprising: a ground wireless device provided on the platform gate; andan on-board wireless device provided on the train, whereinthe communication terminal collects the estimation result from the first wireless terminal using wireless communication, and transmits an opening/closing instruction for the platform doors and doors of the train to both the ground wireless device and the on-board wireless device using wireless communication.

14. The railroad management system according to claim 1, further comprising: a platform gate including a plurality of platform doors;a ground wireless device provided on the platform gate; andan on-board wireless device provided on the train and connectable to the second wireless terminal, whereinthe on-board wireless device gives an instruction to open doors of the train in accordance with a stop timing of the train provided from the second wireless terminal, and transmits a door opening instruction to open the platform doors to the ground wireless device, andthe ground wireless device opens the platform doors in response to the door opening instruction, gives an instruction to close the platform doors, and transmits a door closing instruction to close the doors of the train to the on-board wireless device.

15. The railroad management system according to claim 1, further comprising: a plurality of monitoring cameras to capture the platform;an on-board wireless device provided on the train; anda camera wireless device to receive a monitoring video captured by each of the plurality of monitoring cameras, whereinthe camera wireless device selects a monitoring video to be transmitted to the on-board wireless device based on the track sensed by the track sensing circuitry, and transmits the monitoring video selected to the on-board wireless device.

16. The railroad management system according to claim 15, wherein the second wireless terminal includes the track sensing circuitry,the on-board wireless device is connectable to the second wireless terminal, and transmits a track sensing signal received from the second wireless terminal to the camera wireless device, andthe camera wireless device selects the monitoring video based on the track sensing signal received.

17. The railroad management system according to claim 15, wherein the second wireless terminal includes the track sensing circuitry, generates a track sensing signal indicating the track sensed, and transmits the track sensing signal to the first wireless terminal,the first wireless terminal receives the track sensing signal from the second wireless terminal, and transmits the track sensing signal received to the camera wireless device, andthe camera wireless device selects the monitoring video based on the track sensing signal received.

18. The railroad management system according to claim 15, wherein when a communication link with the on-board wireless device is disconnected, the camera wireless device stops transmitting the monitoring video.

19. The railroad management system according to claim 1, further comprising: a plurality of monitoring cameras to capture the platform;an on-board wireless device connectable to the second wireless terminal and provided on the train;a camera wireless device to receive a monitoring video captured by the monitoring camera; anda core server to receive the monitoring video from the camera wireless device, whereinthe second wireless terminal includes the track sensing circuitry, generates a track sensing signal indicating a track sensed, and transmits the track sensing signal to the on-board wireless device,the on-board wireless device transmits the track sensing signal received from the second wireless terminal to the camera wireless device,the camera wireless device transmits the track sensing signal received to the core server, andthe core server selects a monitoring video to be transmitted to the on-board wireless device based on the track sensing signal, and transmits the monitoring video selected to the on-board wireless device.

20. The railroad management system according to claim 19, wherein the second wireless terminal further includes the distance estimation circuitry, and instructs the core server to stop transmitting the monitoring video when an estimation result satisfies a predetermined condition.

21. A track sensing device comprising: track sensing circuitry to sense a track that a train is entering based on an estimation result obtained by estimating a distance between a first wireless terminal and a second wireless terminal using an ultra-wide band wireless signal transmitted and received by: between the first wireless terminal provided corresponding to each of a plurality of tracks and installed at an end of a platform of a corresponding track and the second wireless terminal installed at an end of the train and configured to perform ultra-wide band wireless communication with the first wireless terminal, transmitting, by the first wireless terminal to the second wireless terminal, an ultra-wide band wireless signal including a signal detection signal different for each track corresponding to the first wireless terminal; detecting, by the second wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each route of the train corresponding to the second wireless terminal; transmitting, by the second wireless terminal to the first wireless terminal, the ultra-wide band wireless signal including the signal detection signal different for each route of the train corresponding to the second wireless terminal; and detecting, by the first wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each track corresponding to the first wireless terminal, whereinthe first wireless terminal and the second wireless terminal use the signal detection signal in common when the route of the track corresponding to the first wireless terminal and the route of the train equipped with the second wireless terminal are identical.

22. A track sensing method comprising: estimating a distance between each of a plurality of first wireless terminals and a second wireless terminal using an ultra-wide band wireless signal transmitted and received, the first wireless terminals being provided corresponding to a plurality of tracks, and each installed at an end of a platform of a corresponding track, the second wireless terminal being installed at an end of a train, and configured to perform communication with the first wireless terminals using an ultra-wide band wireless signal, by: transmitting, by the first wireless terminal to the second wireless terminal, an ultra-wide band wireless signal including a signal detection signal different for each track corresponding to the first wireless terminal; detecting, by the second wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each route of the train corresponding to the second wireless terminal; transmitting, by the second wireless terminal to the first wireless terminal, the ultra-wide band wireless signal including the signal detection signal different for each route of the train corresponding to the second wireless terminal; and detecting, by the first wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each track corresponding to the first wireless terminal; andsensing a track that the train is entering based on an estimation result of the distance between each of the plurality of first wireless terminals and the second wireless terminal, whereinthe first wireless terminal and the second wireless terminal use the signal detection signal in common when the route of the track corresponding to the first wireless terminal and the route of the train equipped with the second wireless terminal are identical.

23. A control circuit that controls a track sensing device that senses a track that a train is entering, the control circuit causing the track sensing device to execute: sensing a track that a train is entering based on an estimation result of a distance between each of a plurality of first wireless terminals and a second wireless terminal, the first wireless terminals being provided corresponding to a plurality of tracks, and each installed at an end of a platform of a corresponding track, the second wireless terminal being installed at an end of the train, and configured to perform communication with the first wireless terminals using an ultra-wide band wireless signal, the estimation result being estimated using the ultra-wide band wireless signal transmitted and received by: transmitting, by the first wireless terminal to the second wireless terminal, an ultra-wide band wireless signal including a signal detection signal different for each track corresponding to the first wireless terminal; detecting, by the second wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each route of the train corresponding to the second wireless terminal; transmitting, by the second wireless terminal to the first wireless terminal, the ultra-wide band wireless signal including the signal detection signal different for each route of the train corresponding to the second wireless terminal; and detecting, by the first wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each track corresponding to the first wireless terminal, whereinthe first wireless terminal and the second wireless terminal use the signal detection signal in common when the route of the track corresponding to the first wireless terminal and the route of the train equipped with the second wireless terminal are identical.

24. A storage medium storing a program for controlling a track sensing device that senses a track that a train is entering, the program causing the track sensing device to execute: sensing a track that a train is entering based on an estimation result of a distance between each of a plurality of first wireless terminals and a second wireless terminal, the first wireless terminals being provided corresponding to a plurality of tracks, and each installed at an end of a platform of a corresponding track, the second wireless terminal being installed at an end of the train, and configured to perform communication with the first wireless terminals using the ultra-wide band wireless signal, the estimation result being estimated using the ultra-wide band wireless signal transmitted and received by: transmitting, by the first wireless terminal to the second wireless terminal, an ultra-wide band wireless signal including a signal detection signal different for each track corresponding to the first wireless terminal; detecting, by the second wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each route of the train corresponding to the second wireless terminal; transmitting, by the second wireless terminal to the first wireless terminal, the ultra-wide band wireless signal including the signal detection signal different for each route of the train corresponding to the second wireless terminal; and detecting, by the first wireless terminal, the ultra-wide band wireless signal received using the signal detection signal different for each track corresponding to the first wireless terminal, whereinthe first wireless terminal and the second wireless terminal use the signal detection signal in common when the route of the track corresponding to the first wireless terminal and the route of the train equipped with the second wireless terminal are identical.