Portable ranging device, train operation system, control circuit, storage medium, and method for determining crew presence inside or outside of vehicle

Abstract

Provided is a portable ranging device (20) capable of improving accuracy in determining whether a crew is present inside or outside a vehicle via wireless communication with an in-vehicle ranging device that is installed inside a train and requires no complicated antenna design. The portable ranging device (20) comprises: an in-vehicle ranging device relative distance calculation unit (25) that calculates relative distances between the portable ranging device (20) and a plurality of in-vehicle ranging devices installed inside the train on the basis of propagation delay time in wireless communication between the portable ranging device (20) and the plurality of in-vehicle ranging devices; a notification information analysis unit (27) that analyzes notification information transmitted by the plurality of in-vehicle ranging devices and acquires installation area information indicating the installation area of each of the in-vehicle ranging devices which are transmission sources of the notification information; an inside / outside vehicle determination unit (26) that determines whether the portable ranging device (20) is inside or outside the train on the basis of the relative distances and the installation area information, and outputs the inside / outside vehicle determination results; and a portable ranging device transmission unit (23) that wirelessly transmits the inside / outside vehicle determination results to the in-vehicle ranging devices.

Description

Portable distance measuring device, train operation system, control circuit, storage medium, and method for determining whether a train driver is inside or outside the train

[0001] The present disclosure relates to a portable distance measuring device carried by a train crew member, a train operation system, a control circuit, a storage medium, and a method for determining whether a crew member is inside or outside a train.

[0002] One possible implementation of an automated train driving system is one in which there is no driver or attendant on board, and only a crew member is on board to respond to unexpected train accidents, malfunctions, and other problems. In such an automated train driving system, it is anticipated that in the event of a problem, the crew member will temporarily leave the train to respond. However, if the train mistakenly believes that the crew member has returned to the train when they have not, and automatically starts moving, this could pose a major problem that disrupts train operations. To avoid such a situation, a means is needed for the train to accurately determine whether the crew member is on board or off the train.

[0003] As a means for determining the position of a crew member on a train, Patent Document 1 discloses a technology for a train operation system that estimates the position of a crew member using ultra-wide band (UWB) technology. The train operation system described in Patent Document 1 has a plurality of UWB wireless sensors installed inside or outside the train, and measures the distance between each UWB wireless sensor and a UWB wireless tag carried by the crew member, thereby estimating the position of the UWB wireless tag based on Cartesian coordinates with a certain position as the origin.

[0004] Patent No. 7229437

[0005] According to the above-mentioned conventional technology, in order to estimate the position of a driver as coordinates, it is basically necessary to measure the distance between three or more UWB wireless sensors and a UWB wireless tag, and the distance measurement must be relatively accurate. Since UWB wireless calculates the distance based on the propagation delay time of radio waves, in order to perform high-accuracy distance measurement, stable communication using direct waves is required without any objects that may cause obstruction or reflection between the transmitter and receiver. Therefore, when a driver with a UWB wireless tag is outside the vehicle, the UWB wireless sensor must ensure line-of-sight of the radio waves even with the UWB wireless tag outside the vehicle.

[0006] For this reason, the above-mentioned conventional technology discloses a method of installing UWB wireless sensors not only inside but also outside the vehicle as one means for determining whether a crew member is inside or outside the vehicle. However, when installing a UWB wireless sensor outside the vehicle, there are many restrictions on installing it on the outside of the vehicle due to the train's construction gauge, and there are problems in that the UWB wireless sensor itself needs to have high environmental resistance to temperature, wind, rain, etc. The above-mentioned conventional technology also discloses a means for determining whether a train is inside or outside using only an in-vehicle UWB wireless sensor. However, because radio waves are forced to reach the outside of the vehicle from the antenna of the in-vehicle UWB wireless sensor, the UWB wireless sensor needs to be equipped with an antenna with low gain for the inside of the vehicle and high gain for the outside of the vehicle, which complicates the antenna design and makes it difficult to apply a small, inexpensive antenna.

[0007] The present disclosure has been made in consideration of the above, and aims to provide a portable ranging device that can improve the accuracy of crew members' determination of whether the vehicle is inside or outside through wireless communication with an in-vehicle ranging device installed inside the train, which does not require a complex antenna design.

[0008] In order to solve the above-mentioned problems and achieve the object, the present disclosure provides a portable ranging device carried by a train crew member. The portable ranging device is characterized by comprising: an in-car ranging device relative distance calculation unit that calculates the relative distance between the portable ranging device and multiple in-car ranging devices installed in a train car based on a propagation delay time of wireless communication between the portable ranging device and multiple in-car ranging devices installed in the train car; a report information analysis unit that analyzes report information transmitted from the multiple in-car ranging devices and acquires installation area information indicating the installation area of ​​the in-car ranging device that transmitted the report information; an in-car / out-of-car determination unit that determines whether the portable ranging device is located inside or outside the train based on the relative distance and the installation area information and outputs the in-car / out-of-car determination result; and a portable ranging device transmission unit that wirelessly transmits the in-car / out-of-car determination result to the in-car ranging devices.

[0009] The portable ranging device disclosed herein has the advantage of being able to improve the accuracy of train crew's determination of whether the vehicle is inside or outside by wireless communication with an in-car ranging device installed inside the train, which does not require a complex antenna design.

[0010] Figure showing an overview of ranging using a general TWR (Two Way Ranging) method. Figure 1 shows an overview to explain that when an in-car ranging device of embodiment 1 is installed inside the train near each door, the position of the portable ranging device can be estimated by calculating the distances between the in-car ranging device and the portable ranging device. Figure 2 shows an overview to explain that when an in-car ranging device of embodiment 1 is installed inside the train near each door, the position of the portable ranging device can be estimated by calculating the distances between the in-car ranging device and the portable ranging device. Figure 3 shows an example of the determination conditions for the in-car / out-of-car determination method for the portable ranging device of embodiment 1. Figure showing an example configuration of a train operation system of embodiment 1. Figure showing an example configuration of an in-car ranging device of embodiment 1. Figure showing an example configuration of a portable ranging device of embodiment 1. Flowchart showing the operation of the portable ranging device of embodiment 1. When the processing circuit realizing the portable ranging device of embodiment 1 is configured with a processor and a memory. FIG. 1 shows an example of the configuration of a processing circuit in the case where the processing circuit realizing the portable ranging device of embodiment 1 is configured with dedicated hardware. FIG. 1 shows an example of the transition over time of the vehicle inside / outside determination result by the vehicle inside / outside determination unit of the portable ranging device of embodiment 2. FIG. 2 shows an example of the transition over time of the vehicle inside / outside determination result by the vehicle inside / outside determination unit of the portable ranging device of embodiment 2. FIG. 3 shows an example of the correction of the vehicle inside / outside determination result by the vehicle inside / outside determination unit of the portable ranging device of embodiment 2. FIG. 4 shows an example of the configuration of a portable ranging device of embodiment 2. Flowchart showing the operation of the portable ranging device of embodiment 2. Schematic diagram for explaining the concept of vehicle inside / outside determination in the portable ranging device of embodiment 3. FIG. 5 shows an example of the configuration of a portable ranging device of embodiment 3. Schematic diagram for explaining the concept of vehicle inside / outside determination in the portable ranging device of embodiment 4. FIG. 6 shows an example of the configuration of a portable ranging device of embodiment 5.

[0011] Hereinafter, a portable distance measuring device, a train operation system, a control circuit, a storage medium, and a method for determining whether a crew member is inside or outside a train according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0012] First Embodiment First, an example of a method for measuring distance by wireless communication, which is the premise of the first embodiment, will be described. FIG. 1 is a diagram showing an outline of distance measurement using a general TWR method. The mobile device 2 transmits transmission time data (transmission time T1) to the fixed device 1. When the fixed device 1 receives the transmission time data (transmission time T1) from the mobile device 2, it responds by adding transmission time data (transmission time T2) for returning a response to the mobile device 2 in addition to the received reception time data (reception time R1). The mobile device 2 can grasp the reception time data (reception time R2) at which it received the response from the fixed device 1, and as a result, it can grasp the time data for the transmission time T1, reception time R1, transmission time T2, and reception time R2.

[0013] The distance between fixed device 1 and mobile device 2 can be calculated from the propagation delay time between fixed device 1 and mobile device 2. This propagation delay time can be calculated in two ways: R1-T1 and R2-T2. If the average of these two propagation delay times is defined as TD, TD can be calculated using the following equation (1).

[0014] TD={(R1-T1)+(R2-T2)}÷2...(1)

[0015] Here, if complete time synchronization is not achieved between the fixed device 1 and the mobile device 2, there will be a difference, even if it is minute, between the times of the two. If it is assumed that the time of the fixed device 1 is off by α compared to the time of the mobile device 2, then R1 should be converted to R1 + α, and T2 should be converted to T2 + α. In this case, equation (1) can be converted to the following equation (2).

[0016] TD=[{(R1+α)-T1}+{R2-(T2+α)}]÷2 = {(R1-T1)+(R2-T2)}÷2...(2)

[0017] In other words, even if there is a time difference α between fixed device 1 and mobile device 2, α cancels out and equation (2) becomes the same as equation (1). Therefore, it is possible to correctly calculate the propagation delay time between fixed device 1 and mobile device 2 regardless of the value of α, and it is possible to calculate the distance between fixed device 1 and mobile device 2 from the result.

[0018] On the other hand, there are methods for calculating distance from the power of a received signal. However, because the power of a received signal tends to fluctuate due to complex weakening and strengthening interactions, such as when reflected waves are present, distance measurement based on the propagation delay time of communication, as described above, generally provides a more accurate distance calculation than distance measurement based on the received power. Therefore, in the first embodiment, distance measurement is performed using a method similar to distance measurement based on the propagation delay time between a fixed device 1 and a mobile device 2, as shown in FIG. 1 . While any wireless signal may be used between the fixed device 1 and the mobile device 2, it is preferable to use, for example, a UWB signal. A UWB signal is an ultrashort pulse signal in the time domain. Using a UWB signal allows the transmission and reception timing of communication to be determined with high precision, enabling highly accurate distance measurement. Furthermore, a UWB signal has the advantage of being able to perform not only highly accurate distance measurement but also data communication in parallel.

[0019] In the following description, a system is assumed in which multiple fixed devices 1 are installed inside a train car, and the system determines whether the train crew is inside or outside the car by determining whether the mobile devices 2 carried by the train crew are inside or outside the car. The fixed devices 1 inside the car are referred to as in-car ranging devices 10, and the mobile devices 2 carried by the train crew are referred to as portable ranging devices 20. It is also assumed that the in-car ranging devices 10 are installed inside the car near each door of the train. Near each door of the train means, for example, above each door, or positions on the left and right of each door, but is not limited to these. The multiple in-car ranging devices 10 are installed inside the train car within a specified range from each door of the train.

[0020] 2 is a first diagram illustrating a schematic diagram for explaining that the position of the portable ranging device 20 can be estimated by calculating the distances between the in-car ranging devices 10a, 10b and the portable ranging device 20 when the in-car ranging devices 10a, 10b according to the first embodiment are installed on the inside of the train near each door. FIG. 3 is a second diagram illustrating a schematic diagram for explaining that the position of the portable ranging device 20 can be estimated by calculating the distances between the in-car ranging devices 10a, 10b and the portable ranging device 20 when the in-car ranging devices 10a, 10b according to the first embodiment are installed on the inside of the train near each door. Note that the in-car ranging devices 10a, 10b are the same as the in-car ranging device 10 described above. Here, FIG. 2 illustrates an example in which the portable ranging device 20 is located inside the train, and FIG. 3 illustrates an example in which the portable ranging device 20 is located outside the train. 2 and 3 show an example in which there are two in-vehicle distance measuring devices 10, but the number of in-vehicle distance measuring devices 10 does not need to be two.

[0021] The portable distance measuring device 20 estimates the distance between the portable distance measuring device 20 and each of the in-vehicle distance measuring devices 10a and 10b by wirelessly exchanging signals with the in-vehicle distance measuring devices 10a and 10b, as in the mobile device 2 and the fixed device 1 shown in FIG. 1 . When the distance measurement result r1 between the portable distance measuring device 20 and the in-vehicle distance measuring device 10a can be estimated, the portable distance measuring device 20 can determine that it exists on a circumference 30a with a radius of r1 centered on the in-vehicle distance measuring device 10a. Similarly, when the distance measurement result r2 between the portable distance measuring device 20 and the in-vehicle distance measuring device 10b can be estimated, the portable distance measuring device 20 can determine that it exists on a circumference 30b with a radius of r2 centered on the in-vehicle distance measuring device 10b. Here, the circumferences 30a and 30b in FIGS. 2 and 3 are depicted assuming that no distance measurement error occurs. 2 and 3, if no distance measurement error occurs, the intersection of the circumferences 30a and 30b is determined to be one point, and the portable distance measuring device 20 is located at that point. Note that the examples in Figures 2 and 3 assume that the portable distance measuring device 20 is located on a straight line passing through the two in-vehicle distance measuring devices 10.

[0022] However, in reality, particularly when the portable ranging device 20 is located outside the vehicle, ranging errors may occur due to obstructions, reflections, etc. during radio wave propagation between the in-vehicle ranging device 10 installed inside the vehicle and the portable ranging device 20 located outside the vehicle. As a result, the intersection of the circle may not be determined to be a single point, and the portable ranging device 20 may not be able to obtain correct position coordinates, resulting in inability to determine whether the vehicle is inside or outside. Furthermore, if the portable ranging device 20 is out of the line of sight of radio waves between some of the in-vehicle ranging devices 10 and can only perform ranging processing with a single in-vehicle ranging device 10, it may not be able to draw multiple circles, and since no intersections are generated, it may not be able to obtain position coordinates, making it impossible to determine whether the vehicle is inside or outside. Therefore, it is desirable to be able to determine whether the vehicle is inside or outside using only information such as the absolute value and relative relationship of the distance between the portable ranging device 20 and the in-vehicle ranging device 10, without estimating the position coordinates of the portable ranging device 20.

[0023] 2 and 3, the upper side is represented as the left side of the train in the direction of travel, and the lower side is represented as the right side of the train in the direction of travel. Also, assume that an in-car ranging device 10 is installed on both the left and right sides of the train in the direction of travel, as shown in FIGS. 2 and 3. Based on the absolute value of the distance measurement result r1 from the in-car ranging device 10a on the left side of the train in the direction of travel, the absolute value of the distance measurement result r2 from the in-car ranging device 10b on the right side of the train in the direction of travel, and the relative relationship between these, we consider determining whether the portable ranging device 20 is located inside or outside the train near each door of the train, and if it is outside the train, whether it is located on the left side or the right side of the train in the direction of travel.

[0024] For example, if the portable distance measuring device 20 is located outside the vehicle on the right side of the vehicle, and the boundary distance from the in-vehicle distance measuring device 10a on the left side of the vehicle to the boundary between the inside and outside of the vehicle at the door on the right side of the vehicle is d1, the distance measurement result r1 should be equal to or greater than the boundary distance d1. Note that it is assumed here that the signal transmitted from the in-vehicle distance measuring device 10a on the left side of the vehicle can be received by the portable distance measuring device 20 outside the vehicle through the door window on the right side of the vehicle.

[0025] On the other hand, with regard to the distance measurement result r2 from the in-vehicle distance measuring device 10b on the right side of the vehicle, the in-vehicle distance measuring device 10b on the right side of the vehicle is installed inside the vehicle, and the distance between the in-vehicle distance measuring device 10b on the right side of the vehicle and the portable distance measuring device 20 located outside the vehicle on the right side of the vehicle is basically outside the line of sight of radio waves. Therefore, the distance measurement result r2 is basically not the result of distance measurement using direct waves, but is the result of distance measurement using diffracted waves, reflected waves, etc. that arrive via other paths, and is expected to be a larger value than the straight-line distance using direct waves, but is thought to be a smaller value than the distance measurement result r1.

[0026] Considering the above, for example, if the following two conditions are met, it is considered that the portable distance measuring device 20 is located outside the vehicle on the right side of the direction of travel. (Condition 1A) The distance measurement result r1 from the in-vehicle distance measuring device 10a on the left side of the direction of travel is equal to or greater than the boundary distance d1. (Condition 1B) The distance measurement result r1 is equal to or greater than the distance measurement result r2 from the in-vehicle distance measuring device 10b on the right side of the direction of travel.

[0027] Furthermore, based on a similar concept, for example, if the following two conditions are met, it is considered that the portable ranging device 20 is located outside the vehicle on the left side of the direction of travel. (Condition 2A) The ranging result r2 from the in-vehicle ranging device 10b on the right side of the direction of travel is greater than or equal to the boundary distance d2. (Condition 2B) The ranging result r1 from the in-vehicle ranging device 10a on the left side of the direction of travel is less than the boundary distance r2. Under the above conditions, boundary distance d2 is the distance from the in-vehicle ranging device 10b on the right side of the direction of travel to the inside / outside vehicle determination boundary of the door on the left side of the direction of travel, and is assumed to be equal to boundary distance d1 due to the structure of the vehicle in which the in-vehicle ranging devices 10a and 10b are installed.

[0028] Furthermore, for example, if it is determined based on the above conditions that the portable ranging device 20 is neither outside the vehicle on the left side nor outside the vehicle on the right side of the direction of travel, the portable ranging device 20 is considered to be inside the vehicle. For simplicity, the above description uses Figures 2 and 3 to explain the case where the portable ranging device 20 is located on a line passing through two in-vehicle ranging devices 10. However, if the portable ranging device 20 is located at a point other than on a line passing through two in-vehicle ranging devices 10, two intersections may occur even if there is no distance measurement error. However, this embodiment is a method for achieving vehicle interior / exterior determination, focusing mainly on the position of the portable ranging device 20 in the direction perpendicular to the direction of travel, and centering around the door. Therefore, there is no difference in the vehicle interior / exterior determination results between these two intersections, and this does not pose any particular problem.

[0029] FIG. 4 shows a table summarizing the determination conditions for the vehicle interior / exterior determination method based on the above-described concept. FIG. 4 illustrates an example of the determination conditions for the vehicle interior / exterior determination method for the portable ranging device 20 according to embodiment 1. The contents of FIG. 4 are similar to those described above or obtained from FIGS. 2 and 3 , and therefore a description of the vehicle interior / exterior determination results based on each determination condition will be omitted. In this manner, by utilizing the absolute value of the distance measurement result r1 between the portable ranging device 20 and the in-vehicle ranging device 10a installed near the left door in the direction of travel, the absolute value of the distance measurement result r2 between the portable ranging device 20 and the in-vehicle ranging device 10b installed near the right door in the direction of travel, and the relative relationship between these, it is possible to determine whether the portable ranging device 20 is inside or outside the vehicle without estimating the position coordinates of the portable ranging device 20. 4 shows an example in which the vehicle is determined to be outside the vehicle (to the right of the traveling direction) when r1≧d1, r2≧d1, and r1≧r2 are satisfied at the top, but the part where r1=r2 is determined to be outside the vehicle (to the left of the traveling direction) because this is a boundary condition for determination between the right side of the traveling direction and the left side of the traveling direction. Also, strictly speaking, since it is not possible to determine whether the vehicle is outside or inside the vehicle, the vehicle inside / outside determination result may be output as "indeterminate," or the most recent vehicle inside / outside determination result may be retained.

[0030] Depending on the positional relationship between the in-car ranging device 10 and the portable ranging device 20, there is a possibility that the distance measurement result itself cannot be obtained because the distance measurement result is completely out of sight. In such a case, the portable ranging device 20 may determine whether the vehicle is inside or outside by utilizing the information that distance measurement was not possible. For example, the portable ranging device 20 may be located at a location extremely far from the in-car ranging device 10 that was unable to measure distance, or may be located in a positional relationship that is basically out of sight of radio waves because the train body is sandwiched between them, as in the positional relationship between the in-car ranging device 10b on the right side of the direction of travel and the portable ranging device 20 located outside the vehicle on the right side of the direction of travel shown in Figure 3, and perform the inside or outside of the vehicle determination based on the information that distance measurement was not possible.

[0031] Figure 5 is a diagram showing an example configuration of a train operation system 50 according to the first embodiment. The train operation system 50 includes multiple in-car ranging devices 10, a portable ranging device 20, and an in-car information aggregation device 40. In the example of Figure 5, the train operation system 50 includes in-car ranging devices 10a-1, 10a-2, 10b-1, and 10b-2 as the multiple in-car ranging devices 10. Here, it is assumed that multiple in-car ranging devices 10 are installed on the inside of the train near each door, and that a crew member who is to be determined as being inside or outside the train carries a portable ranging device 20. Figure 5 also shows an example in which an in-car ranging device 10a-1 is installed on the inside of the car near the left train door A on the left side of the direction of travel, an in-car ranging device 10a-2 is installed on the inside of the car near the left train door B on the left side of the direction of travel, an in-car ranging device 10b-1 is installed on the inside of the car near the right train door A on the right side of the direction of travel, and an in-car ranging device 10b-2 is installed on the inside of the car near the right train door B on the right side of the direction of travel.

[0032] The portable ranging device 20 wirelessly communicates with multiple in-vehicle ranging devices 10 to estimate the distance to each in-vehicle ranging device 10 from the propagation delay time of the signals transmitted and received via wireless communication. The portable ranging device 20 determines whether the device itself, i.e., the portable ranging device 20, is located inside or outside the vehicle using the relative distances measured with each in-vehicle ranging device 10 and information about the installation locations of each in-vehicle ranging device 10. When the portable ranging device 20 performs the in-vehicle / out-of-vehicle determination based on the determination conditions shown in FIG. 4, for example, the portable ranging device 20 can simultaneously determine whether the outside area is on the left side of the vehicle in the direction of travel or on the right side of the vehicle in the direction of travel. Furthermore, when the in-vehicle ranging device 10 transmits information such as an ID (identification) that can identify the in-vehicle ranging device 10, the portable ranging device 20 can also determine which train door the inside or outside of the vehicle it is located near.

[0033] Specifically, when the portable ranging device 20 is outside the vehicle, it can determine, in the example of Fig. 5, whether the portable ranging device 20 is in area A outside the vehicle on the left side of the traveling direction, area B outside the vehicle on the left side of the traveling direction, area A outside the vehicle on the right side of the traveling direction, or area B outside the vehicle on the right side of the traveling direction. Even when the portable ranging device 20 is inside the vehicle, it can determine, in the example of Fig. 5, whether the portable ranging device 20 is in area A inside the vehicle or area B inside the vehicle, based on information such as the ID of the in-vehicle ranging device 10 with which it is communicating wirelessly. The portable ranging device 20 wirelessly transmits the result of the in-vehicle / out-of-vehicle determination to the in-vehicle ranging device 10.

[0034] The in-vehicle ranging device 10 receives the vehicle inside / outside determination result of the portable ranging device 20 wirelessly transmitted from the portable ranging device 20, and transmits the received vehicle inside / outside determination result to the in-vehicle information aggregation device 40. The in-vehicle ranging device 10 may transmit the vehicle inside / outside determination result to the in-vehicle information aggregation device 40 via wired communication or wireless communication.

[0035] Based on the received train interior / exterior determination result, the in-train information aggregation device 40 automatically controls the running of the train on which the crew member carrying the portable distance measuring device 20 is on duty. The in-train information aggregation device 40 automatically controls, for example, the opening and closing of the train doors, the departure of the train, and the like as the automatic control of the running of the train.

[0036] 6 is a diagram showing an example of the configuration of an in-vehicle ranging device 10 according to embodiment 1. The in-vehicle ranging device 10 includes an antenna 11, a circulator 12, an in-vehicle ranging device transmitting unit 13, and an in-vehicle ranging device receiving unit 14. Although the antenna 11 is shown as being external to the in-vehicle ranging device 10 in FIG.

[0037] The circulator 12 is connected to the antenna 11 and separates the radio signal to be transmitted to the portable ranging device 20 from the radio signal transmitted from the portable ranging device 20 and received. The circulator 12 outputs the radio signal output from the in-vehicle ranging device transmitting unit 13 to the antenna 11, and outputs the radio signal received by the antenna 11 to the in-vehicle ranging device receiving unit 14.

[0038] The in-vehicle ranging device transmitter 13 transmits a radio signal via the circulator 12 and the antenna 11. The in-vehicle ranging device 10 not only transmits a signal necessary for calculating the relative distance between the in-vehicle ranging device 10 and the portable ranging device 20 to the portable ranging device 20, but also transmits an ID that can identify the in-vehicle ranging device 10 in the notification information. The portable ranging device 20 associates the ID that can identify the in-vehicle ranging device 10 with installation area information of the in-vehicle ranging device 10 in advance, so that the installation area of ​​each in-vehicle ranging device 10 can be determined by receiving the ID that can identify the in-vehicle ranging device 10 from the in-vehicle ranging device 10. The installation area information of the in-vehicle ranging device 10 refers to, for example, information on the absolute position of the in-vehicle ranging device 10 or information indicating the installation area of ​​the in-vehicle ranging device 10, such as which door the in-vehicle ranging device 10 is installed near on the left or right side of which vehicle number in the direction of travel. In addition, the in-vehicle ranging device 10 may transmit the installation area information itself directly to the portable ranging device 20 via the notification information. In this way, the ID capable of identifying the in-vehicle ranging device 10 included in the notification information may be information such as coordinates capable of specifying the installation location of the in-vehicle ranging device 10, or information indicating which door the in-vehicle ranging device 10 is installed near on the left or right side of the vehicle in the direction of travel of which vehicle number. Information such as coordinates capable of specifying the installation location of the in-vehicle ranging device 10 may be coordinate information based on a specified position. The in-vehicle ranging device transmitter 13 may also transmit information such as the in-vehicle / out-of-vehicle determination conditions exemplified in FIG. 4 and information on the boundary distance d1 required for the determination as notification information to the portable ranging device 20.

[0039] The in-vehicle distance measuring device receiving unit 14 receives the radio signal transmitted from the portable distance measuring device 20 via the antenna 11 and the circulator 12 .

[0040] When the TWR method shown in FIG. 1 is applied, in the in-vehicle distance measuring device 10, the in-vehicle distance measuring device receiving unit 14 measures the reception time R1, and the in-vehicle distance measuring device transmitting unit 13 measures the transmission time T2.

[0041] 7 is a diagram showing an example of the configuration of a portable distance measuring device 20 according to embodiment 1. The portable distance measuring device 20 includes an antenna 21, a circulator 22, a portable distance measuring device transmitter 23, and a portable distance measuring device receiver 24. Although the antenna 21 is shown as being external to the portable distance measuring device 20 in FIG.

[0042] The circulator 22 is connected to the antenna 21 and separates the radio signal to be transmitted to the in-vehicle ranging device 10 from the radio signal transmitted from and received from the in-vehicle ranging device 10. The circulator 22 outputs the radio signal output from the portable ranging device transmitting unit 23 to the antenna 21, and outputs the radio signal received by the antenna 21 to the portable ranging device receiving unit 24.

[0043] The portable ranging device receiving unit 24 receives the radio signal transmitted from the in-vehicle ranging device 10 via the antenna 21 and the circulator 22. The portable ranging device receiving unit 24 includes an in-vehicle ranging device relative distance calculation unit 25, an in-vehicle / out-of-vehicle determination unit 26, and a notification information analysis unit 27.

[0044] The in-vehicle ranging device relative distance calculation unit 25 calculates the relative distance between the portable ranging device 20 and the multiple in-vehicle ranging devices 10 installed inside the train based on the propagation delay time of wireless communication between the portable ranging device 20 and the multiple in-vehicle ranging devices 10. The in-vehicle ranging device relative distance calculation unit 25 includes relative distance calculation units 251-1 to 251-N, where N is an integer of 2 or more. In the following description, when there is no need to distinguish between the relative distance calculation units 251-1 to 251-N, they will be referred to as relative distance calculation units 251. Each relative distance calculation unit 251 calculates the relative distance between the portable ranging device 20 and one in-vehicle ranging device 10.

[0045] The report information analysis unit 27 analyzes the report information transmitted from the multiple in-vehicle ranging devices 10 and acquires installation area information indicating the installation area of ​​the in-vehicle ranging device 10 that transmitted the report information. If the report information includes an ID that can identify the in-vehicle ranging device 10, the report information analysis unit 27 converts the ID that can identify the in-vehicle ranging device 10 into installation area information, and if the report information includes the installation area information of the in-vehicle ranging device 10 itself, the report information analysis unit 27 extracts the installation area information of the in-vehicle ranging device 10 from the report information. Note that when converting an ID that can identify the in-vehicle ranging device 10 into installation area information, the report information analysis unit 27 previously stores information linking the ID that can identify the in-vehicle ranging device 10 with the installation area information of the in-vehicle ranging device 10. In addition, if the vehicle inside / outside determination conditions and information on the boundary distance d1 required for the determination, such as those illustrated in Figure 4, are included in the notification information transmitted from the in-vehicle ranging device 10, the notification information analysis unit 27 may extract and obtain them from the notification information, or they may be stored in advance in the portable ranging device 20.

[0046] The train inside / outside determination unit 26 determines whether the portable ranging device 20 is located inside or outside the train based on the multiple relative distances calculated by the in-train ranging device relative distance calculation unit 25 and the installation area information of the in-train ranging device 10 acquired by the report information analysis unit 27. The train inside / outside determination unit 26 outputs the train inside / outside determination result, which determines whether the portable ranging device 20 is located inside or outside the train, to the portable ranging device transmission unit 23. In addition, when the train is divided into multiple areas inside and outside the train as shown in Figure 5, the train inside / outside determination unit 26 may determine in which of the multiple areas into which the train's inside and outside areas are divided the portable ranging device 20 is located, and output the determination result as part of the train inside / outside determination result. In the example of Figure 7, the vehicle inside / outside determination unit 26 outputs the vehicle inside / outside determination result to the outside of the portable ranging device 20 in addition to the portable ranging device transmission unit 23, but this is not essential and it is not necessary to output the vehicle inside / outside determination result to the outside of the portable ranging device 20.

[0047] The portable distance measuring device transmitter 23 transmits a radio signal via the circulator 22 and the antenna 21. For example, the portable distance measuring device transmitter 23 wirelessly transmits the vehicle inside / outside determination result to the in-vehicle distance measuring device 10 via the circulator 22 and the antenna 21.

[0048] When the TWR method shown in FIG. 1 is applied, in the portable distance measuring device 20, the portable distance measuring device transmitter 23 measures the transmission time T1, and the portable distance measuring device receiver 24 measures the reception time R2.

[0049] 8 is a flowchart showing the operation of the portable ranging device 20 according to the first embodiment. In the portable ranging device 20, the portable ranging device receiving unit 24 waits if it has not received notification information from the in-vehicle ranging device 10 via the antenna 21 and the circulator 22 (step S101: No). If the portable ranging device receiving unit 24 receives notification information from the in-vehicle ranging device 10 (step S101: Yes), the in-vehicle / out-of-vehicle determining unit 26 of the portable ranging device receiving unit 24 designates multiple in-vehicle ranging devices 10 that should respond in the ranging process (step S102). The designated in-vehicle ranging devices 10 respond to the portable ranging device 20.

[0050] In the portable ranging device 20, the in-vehicle ranging device relative distance calculation unit 25 of the portable ranging device receiving unit 24 estimates the propagation delay time using the response signals from each in-vehicle ranging device 10 and calculates the relative distance between the portable ranging device 20 and each in-vehicle ranging device 10 from the propagation delay time (step S103). The in-vehicle / out-of-vehicle determination unit 26 of the portable ranging device receiving unit 24 performs in-vehicle / out-of-vehicle determination to determine whether the portable ranging device 20 is located inside or outside the vehicle using the multiple relative distances calculated by the in-vehicle ranging device relative distance calculation unit 25, i.e., the relative distances to each in-vehicle ranging device 10 (step S104). The portable ranging device transmitting unit 23 obtains the in-vehicle / out-of-vehicle determination result from the in-vehicle / out-of-vehicle determination unit 26 and wirelessly transmits the obtained in-vehicle / out-of-vehicle determination result to the in-vehicle ranging device 10 via the circulator 22 and the antenna 21 (step S105).

[0051] Next, the hardware configuration of the portable distance measuring device 20 will be described. In the portable distance measuring device 20, the antenna 21 is an antenna element. In the portable distance measuring device 20, the other components are realized by a processing circuit. The processing circuit may be a processor and memory that executes a program stored in memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

[0052] FIG. 9 is a diagram showing an example of the configuration of a processing circuit 90 that implements the portable distance measuring device 20 according to the first embodiment, where the processing circuit is configured with a processor 91 and a memory 92. The processing circuit 90 shown in FIG. 9 is a control circuit and includes a processor 91 and a memory 92. When the processing circuit 90 is configured with the processor 91 and the memory 92, each function of the processing circuit 90 is implemented by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in the memory 92. The processing circuit 90 implements each function by having the processor 91 read and execute the program stored in the memory 92. That is, the processing circuit 90 includes the memory 92 for storing a program that results in the processing of the portable distance measuring device 20 being executed. This program can also be considered a program that causes the portable distance measuring device 20 to execute each function implemented by the processing circuit 90. This program can be provided by a storage medium on which the program is stored or by other means such as a communication medium. The above program can also be considered a program that causes the portable distance measuring device 20 to execute the processing shown in the flowchart of FIG. 8.

[0053] Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor), etc. The memory 92 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0054] 10 is a diagram illustrating an example of a processing circuit 93 that implements the portable distance measuring device 20 according to the first embodiment when the processing circuit is configured with dedicated hardware. The processing circuit 93 illustrated in the figure corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The processing circuit may be partially implemented with dedicated hardware and partially implemented with software or firmware. In this way, the processing circuit can implement each of the above-described functions by dedicated hardware, software, firmware, or a combination thereof.

[0055] The hardware configuration of the portable distance measuring device 20 has been described above, but the in-vehicle distance measuring device 10 also has a similar hardware configuration. In the in-vehicle distance measuring device 10, the antenna 11 is an antenna element. In the in-vehicle distance measuring device 10, other components are realized by a processing circuit. The processing circuit may be a processor and memory that executes a program stored in a memory, or may be dedicated hardware.

[0056] In the first embodiment, an example is shown in which information on a plurality of relative distances is collected on the portable ranging device 20 side to determine whether the vehicle is inside or outside, but this is not limiting. Each in-vehicle ranging device 10 may estimate the relative distance between the in-vehicle ranging device 10 and the portable ranging device 20 from the propagation delay time based on the response signal from the portable ranging device 20, and the relative distance information may be collected in a specific in-vehicle ranging device 10, and the in-vehicle ranging device 10 with the collected relative distance information may determine whether the portable ranging device 20 is inside or outside the vehicle.

[0057] Furthermore, in the first embodiment, an example of an in-vehicle distance measuring method led by the portable distance measuring device 20 has been described in which the in-vehicle distance measuring device 10 constantly and periodically transmits notification information, and upon receiving the notification information, the portable distance measuring device 20 responds and starts the distance measuring process, but this is not limiting. For example, a portable distance measuring method led by the portable distance measuring device 20 may also be used in which the portable distance measuring device 20 constantly and periodically transmits notification information such as the ID of its own device, i.e., the portable distance measuring device 20, and upon receiving the notification information from the portable distance measuring device 20, the in-vehicle distance measuring device 10 responds and starts the distance measuring process.

[0058] As described above, according to this embodiment, with multiple in-car ranging devices 10 installed inside the train near each door, the portable ranging device 20 can determine whether the portable ranging device 20 is inside or outside the train using the absolute value of the distance between the portable ranging device 20 and each in-car ranging device 10 and information on the relative relationship, without estimating position coordinates. As a result, the portable ranging device 20 can determine whether the crew is inside or outside the train and also obtain information on the location of the nearest train door without installing the in-car ranging device 10 outside the train or complicating the antenna design of the in-car ranging device 10. The portable ranging device 20 can improve the accuracy of determining whether the crew is inside or outside the train through wireless communication with the in-car ranging device 10 installed inside the train, which does not require a complex antenna design.

[0059] Embodiment 2. In the first embodiment, as an example, when the inside / outside train area determination is performed based on the inside / outside train determination conditions shown in FIG. 4 , it is possible to simultaneously determine whether the outside train area is the outside train area on the left side of the direction of travel or the outside train area on the right side of the direction of travel. Furthermore, it is also possible to determine which train door the inside / outside train area is located around based on information such as an ID for identifying the inside / outside train area transmitted from the inside / outside train distance measuring device 10. However, if a relatively large distance measurement error occurs due to the influence of reflected waves or the like, and the portable distance measuring device 20 momentarily erroneously determines the inside / outside train area, the portable distance measuring device 20 outputs an incorrect inside / outside train determination result. Therefore, in the second embodiment, a case where the portable distance measuring device 20 corrects the determination result of the inside / outside train area is described. In the second embodiment, differences from the first embodiment are described, and the same parts as those in the first embodiment are omitted.

[0060] 11 is a first diagram showing an example of the time transition of the result of the train inside / outside determination by the train inside / outside determination unit 26 of the portable ranging device 20 according to embodiment 2. Fig. 11 shows the time transition when the portable ranging device 20 carried by the train crew is initially inside the train, then exits the train through a train door on the right side of the train's direction of travel, and then returns to the train. Fig. 12 also shows an example in which, after exiting the train through a train door on the right side of the train's direction of travel, a ranging error occurs due to the influence of reflected waves, etc., causing the train inside / outside determination unit 26 to momentarily erroneously determine that the portable ranging device 20 is located outside the train on the left side of the train, and then the ranging error is reduced and the train inside / outside determination unit 26 again determines that the portable ranging device 20 is located outside the train on the right side of the train.

[0061] 12 is a second diagram showing an example of the time transition of the vehicle interior / exterior determination result by the vehicle interior / exterior determination unit 26 of the portable distance measuring device 20 according to embodiment 2. In this case, the driver carrying the portable distance measuring device 20 would realistically have to go through the vehicle interior to move from the outside of the vehicle on the right side of the traveling direction to the outside of the vehicle on the left side of the traveling direction, so this time transition can be interpreted as containing a contradiction. Therefore, in embodiment 2, for the time period when the portable distance measuring device 20 momentarily transitioned to the outside of the vehicle on the left side of the traveling direction in the example of FIG. 12, the portable distance measuring device 20 corrects the determination result to indicate that the vehicle was outside of the vehicle on the right side of the traveling direction, as shown in FIG. 13.

[0062] 13 is a diagram showing an example in which the vehicle inside / outside determination result obtained by the vehicle inside / outside determination unit 26 of the portable distance measuring device 20 according to embodiment 2 is corrected. In order to prevent erroneous determination due to such momentary distance measurement errors, it is also considered effective to take measures such as averaging the time-series data of the calculated relative distance before the portable distance measuring device 20 performs the vehicle inside / outside determination process, or providing hysteresis to the vehicle inside / outside determination threshold value applied to the calculated relative distance, and these measures may be used in combination.

[0063] In the second embodiment, the configuration of the in-vehicle distance measuring device 10 is the same as the configuration of the in-vehicle distance measuring device 10 of the first embodiment shown in FIG. 6, and therefore a description of the in-vehicle distance measuring device 10 will be omitted.

[0064] Fig. 14 is a diagram showing an example of the configuration of a portable distance measuring device 20 according to embodiment 2. The portable distance measuring device 20 shown in Fig. 14 is configured by adding an inside / outside vehicle area discrepancy correction unit 28 to the portable distance measuring device receiving unit 24, in comparison with the portable distance measuring device 20 according to embodiment 1 shown in Fig. 7.

[0065] The vehicle inside / outside determination unit 26 operates in the same manner as in the first embodiment, but outputs the vehicle inside / outside determination result to the vehicle inside / outside area inconsistency correction unit 28 instead of the portable distance measuring device transmission unit 23 .

[0066] The vehicle interior / exterior area inconsistency correction unit 28 checks the time transition of the vehicle interior / exterior determination results output from the vehicle interior / exterior determination unit 26, and if it detects an inconsistency in the order of the time transition, it corrects the inconsistency in the vehicle interior / exterior determination results to eliminate the inconsistency.

[0067] FIG. 15 is a flowchart showing the operation of the portable ranging device 20 according to the second embodiment. In the flowchart shown in FIG. 15, the operations from step S101 to step S104 are the same as those from step S101 to step S104 in the flowchart of the first embodiment shown in FIG. In the second embodiment, after step S104, the portable ranging device receiver 24 in the portable ranging device 20 checks the time transition of the vehicle interior / exterior area discrepancy determination result, and if a discrepancy is detected, corrects the vehicle interior / exterior determination result to resolve the discrepancy (step S201). The portable ranging device transmitter 23 wirelessly transmits the vehicle interior / exterior determination result obtained from the vehicle interior / exterior area discrepancy correction unit 28 to the in-vehicle ranging device 10 via the circulator 22 and the antenna 21 (step S105).

[0068] As described above, according to this embodiment, in the portable distance measuring device 20, the vehicle inside / outside area inconsistency correction unit 28 checks the time transition of the vehicle inside / outside determination result, and corrects the inconsistency in the vehicle inside / outside determination result if an inconsistency is detected in the context of the time transition. This allows the portable distance measuring device 20 to reduce the influence of erroneous determination caused by the radio wave environment, such as reflected waves, and achieves more stable vehicle inside / outside determination compared to the first embodiment.

[0069] Embodiment 3. In Embodiments 1 and 2, the portable ranging device 20 performed the vehicle inside / outside determination using the relative distance between the portable ranging device 20 and the in-vehicle ranging device 10. However, in reality, the relative distance refers to the distance between the portable ranging device 20 and the in-vehicle ranging device 10 when considered in three dimensions. When considering whether the portable ranging device 20 is located inside or outside the vehicle, the two-dimensional distance between the portable ranging device 20 and the in-vehicle ranging device 10 when projected onto a plane horizontal to the ground is important. Therefore, in Embodiment 3, in order to perform vehicle inside / outside determination that is more in line with the real environment, information on the height of the installation position of the in-vehicle ranging device 10 and information on the height of the portable ranging device 20 are used to calculate distance information between the portable ranging device 20 and the in-vehicle ranging device 10 when the relative distance between them is projected onto a plane horizontal to the ground, and this distance information is used to perform vehicle inside / outside determination. In the third embodiment, only the differences from the first and second embodiments will be described, and the same parts as the first and second embodiments will not be described.

[0070] FIG. 16 is a schematic diagram illustrating the concept of the train interior / exterior determination using the portable ranging device 20 according to the third embodiment. In FIG. 16, the in-train ranging device 10a is installed on the inside of the train, above the train door. The relative distance between the portable ranging device 20 and the in-train ranging device 10a is the distance measurement result r1. However, comparing this distance measurement result r1 with the boundary distance d1 does not allow for train interior / exterior determination that is appropriate for the actual environment. To achieve this, it is desirable to calculate the horizontal plane relative distance y, which is the distance when the distance measurement result r1, which is the relative distance, is projected onto a plane horizontal to the ground, and then compare this horizontal plane relative distance y with the boundary distance d1 to determine the train interior / exterior. To achieve this, it is necessary to calculate the horizontal plane relative distance y using the height h1 of the installation position of the in-train ranging device 10a and the height h2 of the portable ranging device 20, using the following equation (3):

[0071] y = √(r ２ - |h1-h2| ２ ) … (3)

[0072] In addition, in the formula (3), √(r1２ - |h1-h2| ２ ) is (r1 ２ - |h1-h2| ２ ) to calculate the horizontal plane relative distance y based on equation (3), the portable ranging device 20 needs to know the height h1 of the installation position of the in-vehicle ranging device 10a and the height h2 of the portable ranging device 20. Here, since the in-vehicle ranging device 10a is fixedly installed inside the train, the height h1 of the installation position of the in-vehicle ranging device 10a is a fixed value. Therefore, by the in-vehicle ranging device 10a including information on the height h1 of the installation position of the in-vehicle ranging device 10a in the broadcast information and transmitting it, the portable ranging device 20 can know the height h1 of the installation position of the in-vehicle ranging device 10a. Regarding the information on the height h1 of the installation position of the in-vehicle ranging device 10a, if the ID capable of identifying the in-vehicle ranging device 10a to be included in the broadcast information is information such as the coordinates capable of specifying the installation position of the in-vehicle ranging device 10a, the information may be included in the information such as the coordinates capable of specifying the installation position of the in-vehicle ranging device 10a.

[0073] On the other hand, the height h2 of the portable distance measuring device 20 is the height of the portable distance measuring device 20 carried by the crew member while performing their duties. Therefore, if the crew member significantly changes the position, i.e., the height, at which the portable distance measuring device 20 is carried, the height h2 of the portable distance measuring device 20 also significantly fluctuates, resulting in the problem of difficulty in consistently obtaining an accurate horizontal plane relative distance y. Therefore, by attaching the portable distance measuring device 20 to a cap, helmet, or the like worn by the crew member while performing their duties, the height h2 of the portable distance measuring device 20 can be maintained at an approximately constant value. In other words, the portable distance measuring device 20 is attached to the cap or helmet worn by the crew member. Since the height h2 of the portable distance measuring device 20 during such operation is expected to vary depending on the crew member's height, etc., the portable distance measuring device 20 is configured to be able to be set externally in advance. This allows the portable distance measuring device 20 to calculate the horizontal plane relative distance y based on equation (3), and to perform vehicle inside / outside determination that is more in line with the actual environment.

[0074] In the third embodiment, the configuration of the in-vehicle distance measuring device 10a is similar to the configuration of the in-vehicle distance measuring device 10 of the first embodiment shown in FIG. 6, and therefore a description of the in-vehicle distance measuring device 10a will be omitted.

[0075] Fig. 17 is a diagram showing an example of the configuration of a portable distance measuring device 20 according to embodiment 3. The portable distance measuring device 20 shown in Fig. 17 is configured by adding an in-vehicle distance measuring device relative distance conversion unit 29 and a portable distance measuring device height setting unit 30 to the portable distance measuring device receiving unit 24, compared to the portable distance measuring device 20 according to embodiment 2 shown in Fig. 14.

[0076] The in-vehicle distance measuring device relative distance calculation unit 25 outputs the calculated relative distances between the portable distance measuring device 20 and the plurality of in-vehicle distance measuring devices 10 a to the in-vehicle distance measuring device relative distance conversion unit 29 .

[0077] The notification information analysis unit 27 performs the same operation as in embodiment 1 or embodiment 2. When the notification information includes information on the height h1 of the installation position of the in-vehicle ranging device 10a, the notification information analysis unit 27 extracts the height h1 of the installation position of the in-vehicle ranging device 10a from the notification information and outputs it to the in-vehicle ranging device relative distance conversion unit 29.

[0078] The portable ranging device height setting unit 30 accepts the height at which the portable ranging device 20 is located, i.e., the height h2 of the portable ranging device 20, and sets it to the in-vehicle ranging device relative distance conversion unit 29. In the portable ranging device 20, if the portable ranging device height setting unit 30 can also accept the height h1 of the installation position of the in-vehicle ranging device 10a, the portable ranging device height setting unit 30 may set the accepted height h1 of the installation position of the in-vehicle ranging device 10a to the in-vehicle ranging device relative distance conversion unit 29.

[0079] The in-vehicle ranging device relative distance conversion unit 29 converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit 25 into a horizontal plane relative distance y between the in-vehicle ranging device 10a and the portable ranging device 20 when projected onto a plane horizontal to the ground. Specifically, the in-vehicle ranging device relative distance conversion unit 29 converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit 25 into a horizontal plane relative distance y using the difference between the height h1 of the installation position of the in-vehicle ranging device 10a, which is fixed in its installation position inside the train, and the height h2 at which the portable ranging device 20 is located. The in-vehicle ranging device relative distance conversion unit 29 includes relative distance conversion units 291-1 to 291-N, where N is an integer equal to or greater than 2. In the following description, when there is no need to distinguish between the relative distance conversion units 291-1 to 291-N, they will be referred to as relative distance conversion units 291. Each relative distance converter 291 converts the relative distance between the portable ranging device 20 and one in-vehicle ranging device 10a into a horizontal plane relative distance y. The in-vehicle ranging device relative distance converter 29 may obtain the height h1 of the installation position of the in-vehicle ranging device 10a from the notification information analyzer 27, from the portable ranging device height setting unit 30, or may store the height h1 in advance.

[0080] The train interior / exterior determination unit 26 determines whether the portable ranging device 20 is located inside or outside the train, based on the multiple horizontal plane relative distances y converted by the in-train ranging device relative distance conversion unit 29 and the installation area information of the in-train ranging device 10a acquired by the alarm information analysis unit 27. The third embodiment differs from the first and second embodiments in that the train interior / exterior determination unit 26 uses the multiple horizontal plane relative distances y converted by the in-train ranging device relative distance conversion unit 29, rather than the multiple relative distances calculated by the in-train ranging device relative distance calculation unit 25. However, the train interior / exterior determination process of the train interior / exterior determination unit 26 in the third embodiment is the same as the train interior / exterior determination process of the train interior / exterior determination unit 26 in the first and second embodiments.

[0081] As described above, according to this embodiment, the portable ranging device 20 converts the calculated relative distance between the in-vehicle ranging device 10a and the portable ranging device 20 using the height h1 of the installation position of the in-vehicle ranging device 10a and the height h2 of the portable ranging device 20 into a horizontal plane relative distance y, which is the relative distance between the in-vehicle ranging device 10a and the portable ranging device 20 in two dimensions when projected onto a plane horizontal to the ground, and performs vehicle inside / outside determination using the horizontal plane relative distance y. This allows the portable ranging device 20 to perform vehicle inside / outside determination that is more suited to the real environment than in embodiments 1 and 2.

[0082] Embodiment 4 In embodiment 3, in order to perform vehicle inside / outside determination that is more in line with the actual environment, the height h2 of the portable distance measuring device 20 is manually set in advance for the portable distance measuring device 20. In embodiment 4, a case will be described in which the height h2 of the portable distance measuring device 20 is not manually set for the portable distance measuring device 20. Note that in embodiment 4, only the differences from embodiment 3 will be described, and a description of the same parts as in embodiment 3 will be omitted.

[0083] In embodiment 4, before starting work, the crew sets the portable ranging device 20 to a specific mode such as ``automatic setting mode,'' then carries the portable ranging device 20 and stands at a predetermined location, and performs wireless communication with a specific in-vehicle ranging device 10.

[0084] FIG. 18 is a schematic diagram for explaining the concept of train interior / exterior determination using the portable ranging device 20 according to the fourth embodiment. In FIG. 18, the horizontal position of the portable ranging device 20 differs from that of FIG. 16 described in the third embodiment. In FIG. 18, the train crew member carrying the portable ranging device 20 is standing at the train interior / exterior boundary at the right train door in the direction of travel. In this case, the horizontal relative distance y between the in-train ranging device 10a and the portable ranging device 20 in the Y-axis direction is equivalent to the train width and is the same as the boundary distance d1. Furthermore, if the relative distance between the in-train ranging device 10a and the portable ranging device 20 when the train crew member is standing at the position shown in FIG. 18 is taken as the distance measurement result r1, the difference |h1-h2| between the height h1 of the installation position of the in-train ranging device 10a and the height h2 of the portable ranging device 20 can be calculated using the following equation (4):

[0085] |h1-h2|=√(r1 ２ -d1 ２ ) … (4)

[0086] In addition, in the formula (4), √(r1 ２ -d1 ２ ) is (r1 ２ -d1 ２ ) is expressed as the square root of |h1-h2|. In this way, the portable ranging device 20 can calculate |h1-h2| from equation (4) simply by measuring the distance with a specific in-vehicle ranging device 10a at a predetermined position before starting work. By automatically storing the value of |h1-h2| before starting work, the portable ranging device 20 does not need to obtain the height h1 of the installation position of the in-vehicle ranging device 10a from notification information from the in-vehicle ranging device 10a, nor does it need to receive the height h2 of the portable ranging device 20 from a crew member or the like. It can automatically calculate the horizontal plane relative distance y using equation (4) for the ranging result r1, which is the relative distance between each in-vehicle ranging device 10a.

[0087] As can be seen from equation (3) described in embodiment 3, the information required to calculate the horizontal plane relative distance y is the distance measurement result r1 and the difference |h1-h2| between the height h1 of the installation position of the in-vehicle distance measuring device 10a and the height h2 of the portable distance measuring device 20. The distance measurement result r1 can be estimated using the method described in embodiment 1 or embodiment 2. In embodiment 3, the height h1 of the installation position of the in-vehicle distance measuring device 10a is set to a fixed value, and the height h2 of the portable distance measuring device 20 is set to a value set by the portable distance measuring device height setting unit 30, and the difference |h1-h2| is calculated using these two values. However, the information required to calculate the horizontal plane relative distance y is the difference |h1-h2| between the height h1 of the installation position of the in-vehicle ranging device 10a and the height h2 of the portable ranging device 20.Therefore, if the difference |h1-h2| between the height h1 of the installation position of the in-vehicle ranging device 10a and the height h2 of the portable ranging device 20 can be obtained from equation (4), then individual information on the height h1 of the installation position of the in-vehicle ranging device 10a and the height h2 of the portable ranging device 20 is not required.

[0088] For example, if the difference |h1-h2| between the height h1 of the installation position of the in-train distance measuring device 10a and the height h2 of the portable distance measuring device 20 is 0.5 m, then h1 = 2.0 m and h2 = 1.5 m may be used, or h1 = 2.3 m and h2 = 1.8 m may be used, and the combination of h1 and h2 is not particularly important. As such, in the fourth embodiment, it is not necessary to set in advance the height h1 of the installation position of the in-train distance measuring device 10a or the height h2 of the portable distance measuring device 20, and therefore the convenience of the train operation system 50 can be improved compared to the third embodiment.

[0089] In the fourth embodiment, the configuration of the in-vehicle distance measuring device 10a is the same as the configuration of the in-vehicle distance measuring device 10 of the first embodiment shown in FIG. 6, and therefore a description of the in-vehicle distance measuring device 10a will be omitted.

[0090] Fig. 19 is a diagram showing a configuration example of a portable distance measuring device 20 according to embodiment 4. The portable distance measuring device 20 shown in Fig. 19 is configured by replacing the portable distance measuring device height setting unit 30 with a height difference calculation unit 31 in the portable distance measuring device 20 according to embodiment 3 shown in Fig. 17.

[0091] When the "automatic setting mode" is set, the height difference calculation unit 31 calculates the difference |h1-h2| between the height h1 of the installation position of the in-car ranging device 10a and the height h2 of the portable ranging device 20. Specifically, the height difference calculation unit 31 calculates the difference |h1-h2| between the height h1 of the installation position of the in-car ranging device 10a and the height at which the portable ranging device 20 is located, i.e., the height h2 of the portable ranging device 20, using the relative distance calculated by the in-car ranging device relative distance calculation unit 25 when the crew member carrying the portable ranging device 20 stands at a specified position inside the train and the portable ranging device 20 performs wireless communication with the specified in-car ranging device 10a, and the boundary distance d1, which is distance information when projected onto a plane horizontal to the ground, between the installation position of the specified in-car ranging device 10a, which is fixed in its installation position inside the train, and the position at which the crew member is standing. If the information on the boundary distance d1 is included in the notification information transmitted from the in-vehicle distance measuring device 10a, the height difference calculation unit 31 may obtain the information on the boundary distance d1 from the notification information analysis unit 27 that extracted the information on the boundary distance d1 from the notification information, or may store the information in advance. The height difference calculation unit 31 sets the calculated difference |h1-h2| in the in-vehicle distance measuring device relative distance conversion unit 29.

[0092] The in-vehicle ranging device relative distance conversion unit 29 converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit 25 into the horizontal plane relative distance y between the in-vehicle ranging device 10a and the portable ranging device 20 when projected onto a plane horizontal to the ground. In the fourth embodiment, the in-vehicle ranging device relative distance conversion unit 29 converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit 25 into the horizontal plane relative distance y using the difference |h1-h2| between the height h1 of the installation position of the in-vehicle ranging device 10a set by the height difference calculation unit 31 and the height at which the portable ranging device 20 is located, i.e., the height h2 of the portable ranging device 20. The in-vehicle ranging device relative distance conversion unit 29 does not need to acquire the height h1 of the installation position of the in-vehicle ranging device 10a from the alarm information analysis unit 27, nor does it need to store it in advance.

[0093] As explained above, according to this embodiment, the portable ranging device 20 automatically sets the difference |h1-h2| between the height h1 of the installation position of the in-car ranging device 10a and the height h2 of the portable ranging device 20 by having the crew member carry the portable ranging device 20 and stand at a specified position inside the train before starting work, and have the portable ranging device 20 measure the distance between the portable ranging device 20 and a specific in-car ranging device 10a. As a result, the portable ranging device 20 can improve the convenience of the train operation system 50 compared to the third embodiment.

[0094] Embodiment 5. In embodiments 3 and 4, it was assumed that the height h1 of the installation position of the in-vehicle distance measuring device 10a was fixed. However, the height h1 of the installation position of the in-vehicle distance measuring device 10a may vary depending on the type of vehicle that makes up the train. Furthermore, even within the same vehicle, the height h1 of the installation position of the in-vehicle distance measuring device 10a may vary depending on the installation location of the in-vehicle distance measuring device 10a. Therefore, in embodiment 5, a case where the height h1 of the installation position of the in-vehicle distance measuring device 10a varies depending on the in-vehicle distance measuring device 10a in the train will be described. Note that in embodiment 5, differences from embodiments 1 to 4 will be described, and descriptions of the same parts as embodiments 1 to 4 will be omitted.

[0095] First, the case of embodiment 3 will be described. In the case of embodiment 3, the portable distance measuring device 20 receives the height h2 of the portable distance measuring device 20 from the portable distance measuring device height setting unit 30. In embodiment 5, the portable distance measuring device 20 receives the height h2 of the portable distance measuring device 20 from the portable distance measuring device height setting unit 30, just like in embodiment 3.

[0096] In the case of the third embodiment, the portable ranging device 20 may extract the height h1 of the installation position of the in-vehicle ranging device 10a from the broadcast information, may obtain it from the portable ranging device height setting unit 30, or may store it in advance. Here, the fifth embodiment assumes that there are in-vehicle ranging devices 10a installed at different heights h1 on the train. Therefore, it is not realistic for the portable ranging device 20 to obtain the height h1 of the installation position of the in-vehicle ranging device 10a from the portable ranging device height setting unit 30 or to store it in advance. Therefore, in the fifth embodiment, in which there are in-vehicle ranging devices 10a installed at different heights h1 on the train, the portable ranging device 20 obtains information on the height h1 of the installation position of the in-vehicle ranging device 10a from the broadcast information broadcast by each in-vehicle ranging device 10a. In the fifth embodiment, the in-vehicle distance measuring device 10a transmits notification information including information on the height h1 of the installation position of the device itself, that is, the in-vehicle distance measuring device 10a.

[0097] As a result, the portable ranging device 20 can determine the height h1 of the installation location of the in-vehicle ranging device 10a that is the source of the reporting information by acquiring notification information from the in-vehicle ranging device 10a in the vicinity where the portable ranging device 20 is located. Once the portable ranging device 20 has acquired information on the height h1 of the installation location of the in-vehicle ranging device 10a and the height h2 of the portable ranging device 20, it can determine whether the crew member is inside or outside the vehicle by performing the same operations as in the third embodiment.

[0098] That is, in the fifth embodiment, the alarm information analysis unit 27 acquires information on the height h1 of the installation position of the in-vehicle ranging device 10a from the alarm information. The in-vehicle ranging device relative distance conversion unit 29 converts the distance measurement result r1, which is the relative distance calculated by the in-vehicle ranging device relative distance calculation unit 25, into a horizontal plane relative distance y using the difference between the height h1 of the installation position of the in-vehicle ranging device 10a acquired by the alarm information analysis unit 27 and the height h2 at which the portable ranging device 20 is located, accepted by the portable ranging device height setting unit 30.

[0099] Next, the case of embodiment 4 will be described. In the case of embodiment 4, the portable distance measuring device 20 did not acquire specific value information for either the height h1 of the installation position of the in-vehicle distance measuring device 10a or the height h2 of the portable distance measuring device 20. Here, the portable distance measuring device 20 can acquire the height h1 of the installation position of the in-vehicle distance measuring device 10a from the notification information from the in-vehicle distance measuring device 10a, as described in the case of embodiment 3 above. Therefore, once the portable distance measuring device 20 can acquire information on the height h2 of the portable distance measuring device 20, it can determine whether the driver is inside or outside the vehicle by performing the same operation as in embodiment 3. Below, a method by which the portable distance measuring device 20 automatically calculates the height h2 of the portable distance measuring device 20 will be described.

[0100] Fig. 20 is a diagram showing a configuration example of a portable ranging device 20 according to embodiment 5. The portable ranging device 20 shown in Fig. 20 is the same as the portable ranging device 20 according to embodiment 4 shown in Fig. 19, except that the height difference calculation unit 31 is replaced with an automatic portable ranging device height calculation unit 32. Note that Fig. 20 also includes arrows indicating the flow of operation in which the notification information analysis unit 27 outputs information about the height h1 of the installation position of the in-vehicle ranging device 10a, which information is obtained from the notification information, to the in-vehicle ranging device relative distance conversion unit 29 and the automatic portable ranging device height calculation unit 32.

[0101] The portable ranging device height automatic calculation unit 32 automatically calculates the height h2 at which the portable ranging device 20 is located and sets this to the in-vehicle ranging device relative distance conversion unit 29. The relationship between the height h1 of the installation position of the in-vehicle ranging device 10a and the height h2 at which the portable ranging device 20 is located is considered to be h1 > h2, since the in-vehicle ranging device 10a is often installed above the doors of trains. Therefore, the portable ranging device height automatic calculation unit 32 can automatically calculate the height h2 at which the portable ranging device 20 is located by modifying equation (4) explained in the fourth embodiment into the following equation (5).

[0102] h2=h1-√(r1 ２ -d1 ２ ) … (5)

[0103] In addition, in the formula (5), √(r1 ２ -d1２ ) represents the square root of (r1 ２ - d1 ２ ). Here, when h1 < h2, it may not be possible to calculate an accurate value from Equation (5). Therefore, the portable distance measuring device height automatic calculation unit 32 may cause the crew to confirm the height h2 at which the automatically calculated portable distance measuring device 20 exists. The portable distance measuring device height automatic calculation unit 32 may display the automatically calculated height h2 at which the portable distance measuring device 20 exists on a display unit (not shown) for the method of causing the crew to confirm, or may output it as audio from a speaker (not shown) or the like. When h1 < h2 always holds, Equation (5) may be transformed as "h2 = h1 + √(r1 ２ - d1 ２ ). The portable distance measuring device height automatic calculation unit 32 may obtain information on the boundary distance d1 from the notification information analysis unit 27 that extracts the information on the boundary distance d1 from the notification information when the information on the boundary distance d1 is included in the notification information transmitted from the in-vehicle distance measuring device 10a, or may hold it in advance. If the portable distance measuring device 20 automatically calculates the height h2 at which the portable distance measuring device 20 exists once using Equation (5), it can then perform the same operations as in the case of Embodiment 3.

[0104] That is, in Embodiment 5, the notification information analysis unit 27 obtains information on the height h1 of the installation position of the in-vehicle distance measuring device 10a from the notification information. The in-vehicle distance measuring device relative distance conversion unit 29 uses the difference between the height h1 of the installation position of the in-vehicle distance measuring device 10a obtained by the notification information analysis unit 27 and the height h2 at which the portable distance measuring device 20 exists calculated by the portable distance measuring device height automatic calculation unit 32 to convert the distance measurement result r1, which is the relative distance calculated by the in-vehicle distance measuring device relative distance calculation unit 25, into the horizontal plane relative distance y.

[0105] As explained above, according to this embodiment, even if the height h1 of the installation position of the in-car ranging device 10a varies depending on the in-car ranging device 10a within the same train, the portable ranging device 20 can convert the calculated relative distance between the in-car ranging device 10a and the portable ranging device 20 using the height h1 of the installation position of the in-car ranging device 10a and the height h2 of the portable ranging device 20 into a horizontal plane relative distance y, which is the relative distance between the in-car ranging device 10a and the portable ranging device 20 in two dimensions when projected onto a plane horizontal to the ground, and can perform inside / outside vehicle determination using the horizontal plane relative distance y. As with embodiments 3 and 4, the portable ranging device 20 can perform inside / outside vehicle determination that is more suited to the real environment.

[0106] Embodiment 6. In the trains assumed in embodiments 1 to 5, a display device that displays information about train stops and train operations is often mounted above the interior doors. The in-car ranging device 10 of embodiments 1 to 5 is assumed to be installed inside the train near each door. For this reason, the in-car ranging device 10 and the above-mentioned display device are integrated into one unit, i.e., the in-car ranging device 10 is integrated with a display device installed inside the train that displays information about train operations. This allows for improvements in terms of labor savings and a reduction in the number of wires when installing the in-car ranging device 10.

[0107] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0108] 1 Fixed device, 2 Mobile device, 10, 10a, 10a-1, 10a-2, 10b, 10b-1, 10b-2 In-vehicle distance measuring device, 11, 21 Antenna, 12, 22 Circulator, 13 In-vehicle distance measuring device transmitter, 14 In-vehicle distance measuring device receiver, 20 Portable distance measuring device, 23 Portable distance measuring device transmitter, 24 Portable distance measuring device receiver, 25 In-vehicle distance measuring device relative distance calculation unit, 26 In-vehicle / outside determination unit, 27 Notification information analysis unit, 28 In-vehicle / outside area discrepancy correction unit, 29 In-vehicle distance measuring device relative distance conversion unit, 30 Portable distance measuring device height setting unit, 31 Height difference calculation unit, 32 Portable distance measuring device height automatic calculation unit, 40 In-vehicle information aggregation device, 50 Train operation system, 90, 93 Processing circuit, 91 Processor, 92 Memory, 251-1 to 251-N relative distance calculation units, 291-1 to 291-N relative distance conversion units.

Claims

1. A portable ranging device carried by a train crew member, comprising: an in-car ranging device relative distance calculation unit that calculates the relative distance between the portable ranging device and multiple in-car ranging devices installed inside the train based on the propagation delay time of wireless communication between the portable ranging device and multiple in-car ranging devices; a report information analysis unit that analyzes report information transmitted from the multiple in-car ranging devices and obtains installation area information indicating the installation area of ​​the in-car ranging device that is the sender of the report information; an in-car / out-of-car determination unit that determines whether the portable ranging device is inside or outside the train based on the relative distance and the installation area information and outputs the in-car / out-of-car determination result; and a portable ranging device transmission unit that wirelessly transmits the in-car / out-of-car determination result to the in-car ranging device.

2. The portable ranging device described in claim 1, characterized in that the inside / outside determination unit determines in which of multiple areas the inside and outside of the train are divided into multiple areas the portable ranging device is located, and outputs the determination result together with the inside / outside determination result.

3. The portable distance measuring device of claim 2 further comprises an inside / outside area inconsistency correction unit that checks the time transition of the inside / outside determination result output from the inside / outside determination unit, and corrects the inside / outside determination result to eliminate the inconsistency if an inconsistency is detected in the order of the time transition.

4. A portable ranging device as described in any one of claims 1 to 3, further comprising: an in-vehicle ranging device relative distance conversion unit that converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into a horizontal plane relative distance between the in-vehicle ranging device and the portable ranging device when projected onto a plane horizontal to the ground; and a portable ranging device height setting unit that receives the height at which the portable ranging device is located and sets it in the in-vehicle ranging device relative distance conversion unit, wherein the in-vehicle ranging device relative distance conversion unit converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into the horizontal plane relative distance using the difference between the height at which the in-vehicle ranging device, which is installed in a fixed position within the train, is installed and the height at which the portable ranging device is located.

5. The train further comprises an in-car ranging device relative distance conversion unit that converts the relative distance calculated by the in-car ranging device relative distance calculation unit into a horizontal plane relative distance between the in-car ranging device and the portable ranging device when projected onto a plane horizontal to the ground; and a height difference calculation unit that calculates the difference between the height of the installation position of the in-car ranging device and the height at which the portable ranging device is located, using the relative distance calculated by the in-car ranging device relative distance calculation unit when the crew member carrying the portable ranging device stands at a specified position inside the train and the portable ranging device performs wireless communication with the specified in-car ranging device, and distance information when projected onto a plane horizontal to the ground between the installation position of the specified in-car ranging device, which is fixed in place inside the train, and the position where the crew member is standing, and calculates the difference in height between the installation position of the in-car ranging device and the height at which the portable ranging device is located, and sets the difference in height to the in-car ranging device relative distance conversion unit. A portable ranging device as described in any one of claims 1 to 3, characterized in that the in-vehicle ranging device relative distance conversion unit converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into the horizontal plane relative distance using the difference between the height of the installation position of the in-vehicle ranging device set by the height difference calculation unit and the height at which the portable ranging device is located.

6. A portable ranging device as described in any one of claims 1 to 3, further comprising: an in-vehicle ranging device relative distance conversion unit that converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into a horizontal plane relative distance between the in-vehicle ranging device and the portable ranging device when projected onto a plane horizontal to the ground; and a portable ranging device height setting unit that accepts the height at which the portable ranging device is located and sets it in the in-vehicle ranging device relative distance conversion unit, wherein the notification information analysis unit acquires information on the height of the installation position of the in-vehicle ranging device from the notification information, and the in-vehicle ranging device relative distance conversion unit converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into the horizontal plane relative distance using the difference between the height of the installation position of the in-vehicle ranging device acquired by the notification information analysis unit and the height at which the portable ranging device is located accepted by the portable ranging device height setting unit.

7. A portable ranging device as described in any one of claims 1 to 3, further comprising: an in-vehicle ranging device relative distance conversion unit that converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into a horizontal plane relative distance between the in-vehicle ranging device and the portable ranging device when projected onto a plane horizontal to the ground; and an automatic portable ranging device height calculation unit that automatically calculates the height at which the portable ranging device is located and sets the height at which the portable ranging device is located in the in-vehicle ranging device relative distance conversion unit, wherein the notification information analysis unit obtains information on the height of the installation position of the in-vehicle ranging device from the notification information, and the in-vehicle ranging device relative distance conversion unit converts the relative distance calculated by the in-vehicle ranging device relative distance calculation unit into the horizontal plane relative distance using the difference between the height of the installation position of the in-vehicle ranging device obtained by the notification information analysis unit and the height at which the portable ranging device is located calculated by the automatic portable ranging device height calculation unit.

8. A train operation system comprising: a portable ranging device according to any one of claims 1 to 7; a plurality of on-board ranging devices that receive the inside / outside determination results of the portable ranging devices wirelessly transmitted from the portable ranging devices and transmit the inside / outside determination results to an on-board information aggregation device; and the on-board information aggregation device that automatically controls the running of trains on board that are manned by crew members carrying the portable ranging devices, based on the inside / outside determination results.

9. The train operation system according to claim 8, wherein the plurality of on-board distance measuring devices are installed within a specified range from each door of the train inside the train.

10. The train operation system according to claim 8 or 9, wherein the portable distance measuring device is attached to a hat or helmet worn by the train crew member.

11. A train operation system as described in any one of claims 8 to 10, characterized in that the on-board distance measuring device is integrated with a display device installed inside the train that displays information about train operations.

12. A control circuit for controlling a portable ranging device carried by a train crew member, characterized in that the control circuit causes the portable ranging device to perform the following: calculate the relative distance between multiple on-board ranging devices installed inside the train based on the propagation delay time of wireless communication with the multiple on-board ranging devices; analyze notification information transmitted from the multiple on-board ranging devices and obtain installation area information indicating the installation areas of the multiple on-board ranging devices; determine whether the portable ranging device is inside or outside the train based on the relative distance and the installation area information, and output the inside / outside determination result; and wirelessly transmit the inside / outside determination result to the on-board ranging device.

13. A storage medium storing a program for controlling a portable ranging device carried by a train crew member, characterized in that the program causes the portable ranging device to perform the following: calculate the relative distance between multiple on-board ranging devices based on the propagation delay time of wireless communication with multiple on-board ranging devices installed inside the train; analyze notification information transmitted from the multiple on-board ranging devices and obtain installation area information indicating the installation areas of the multiple on-board ranging devices; determine whether the portable ranging device is inside or outside the train based on the relative distance and the installation area information, and output the inside / outside determination result; and wirelessly transmit the inside / outside determination result to the on-board ranging device.

14. A method for determining whether a crew member is inside or outside the train using a portable ranging device carried by a train crew member, comprising: a first step in which an in-car ranging device relative distance calculation unit calculates the relative distance between the in-car ranging devices and multiple in-car ranging devices installed inside the train based on the propagation delay time of wireless communication with the multiple in-car ranging devices; a second step in which a notification information analysis unit analyzes notification information transmitted from the multiple in-car ranging devices and obtains installation area information indicating the installation areas of the multiple in-car ranging devices; a third step in which an in-car / out-of-car determination unit determines whether the portable ranging device is inside or outside the train based on the relative distance and the installation area information and outputs the in-car / out-of-car determination result; and a fourth step in which a portable ranging device transmission unit wirelessly transmits the in-car / out-of-car determination result to the in-car ranging device.

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