JP7738620B2 - Wireless communication device and railway vehicle communication system - Google Patents

Description

The present invention relates to a wireless communication device installed in a railway vehicle and a railway vehicle communication system.

In recent years, railway vehicles have been equipped with display devices in passenger compartments to display, for example, the next stop or advertisements. This type of display device has a server installed, for example, in the lead car, and distributes information from there to the displays in each car (see, for example, Patent Document 1).

JP 2010-16575 A

A system like the one described in Patent Document 1 could be installed when manufacturing new vehicles, but installing it on existing vehicles would require modifying the vehicles. In particular, building a network spanning multiple vehicles requires wiring work to the electrical couplers, which increases implementation costs.

Furthermore, if a network has already been established within a vehicle or train configuration, multiple networks must be connected when linking them to form a train. This requires reconfiguring the train's network, which is time-consuming.

The present invention therefore aims to provide a wireless communication device and a railway vehicle communication system that allows network systems to be easily added to existing vehicles.

The invention described in claim 1, which was made to solve the above problem, is a wireless communication device comprising: a radio wave wireless communication unit that receives radio waves from a wireless repeater installed in the railway vehicle and transmits radio waves to the wireless repeater; and an optical wireless communication unit that irradiates an optical signal to another railway vehicle coupled to the railway vehicle and receives an optical signal from the other railway vehicle; the radio wave wireless communication unit converts transmission information contained in the received radio waves into an electrical signal and outputs it to the optical wireless communication unit; the optical wireless communication unit converts the transmission information into an optical signal and irradiates it to the other railway vehicle; the optical wireless communication unit converts transmission information contained in the optical signal received from the other railway vehicle into an electrical signal and outputs it to the radio wave wireless communication unit; and the radio wave wireless communication unit transmits the transmission information in radio waves to the wireless repeater.

According to the present invention, the optical wireless communication unit eliminates the need for wiring to electrical couplers between vehicles. Furthermore, the radio wireless communication unit eliminates the need for additional wired wiring within the vehicle. Therefore, network systems can be easily added to existing vehicles.

1 is a schematic configuration diagram of a railway vehicle communication system according to an embodiment of the present invention; 2 is an example of installation of the optical wireless communication device shown in FIG. 1. FIG. 2 is a functional configuration diagram of the optical wireless communication device shown in FIG. 1 . FIG. 1 is a schematic diagram of a train consisting of multiple cars.

One embodiment of the present invention will now be described with reference to Figures 1 to 4. Figure 1 is a schematic diagram of a railway vehicle communication system according to one embodiment of the present invention. The railway vehicle communication system is installed on a train made up of multiple railway vehicles coupled together, but Figure 1 shows only the essential parts.

The railway vehicle communication system 1 shown in Figure 1 includes an optical wireless communication device 11, a wireless LAN access point 12, in-car display devices 13 and 14, an optical wireless communication device 21, a wireless LAN access point 22, and a video distribution device 23.

Of the components shown in Figure 1, the optical wireless communication device 11, wireless LAN access point 12, and in-car display devices 13 and 14 are provided in train formation A. On the other hand, the optical wireless communication device 21, wireless LAN access point 22, and video distribution device 23 are provided in train formation B.

Train set A consists of one or more cars, including at least railcar Ta. In Figure 1, only railcar Ta is shown as train set A, but it may be made up of multiple cars. Train set B consists of one or more cars, including at least railcar Tb. In Figure 1, only railcar Tb is shown as train set B, but it may be made up of multiple cars. Train sets A and B may be coupled together at a depot, or, for example, during rush hour, train set B may be coupled to train set A at a specified station, etc.

The optical wireless communication device 11 is provided on railway car Ta, which is one of the railway cars that make up formation A and is coupled to formation B. The optical wireless communication device 11 is provided opposite the optical wireless communication device 21 provided on railway car Tb of formation B. The optical wireless communication device 11 is installed, for example, in a window of railway car Ta facing railway car Tb. Figure 2 shows an example of the installation of the optical wireless communication device 11.

Figure 2 shows an example in which the optical wireless communication device 11 is installed behind (inside the window) the front window of a driver's cab located at the end of a railway vehicle Ta. As shown in Figure 2, a front window W is provided above the control panel 51 in the driver's cab. In Figure 2, the optical wireless communication device 11 is installed above the front window W. In Figure 2, the tracks can be seen beyond the front window and a railway vehicle Tb is not coupled, but when constructing a railway vehicle communication system 1, the railway vehicle Tb can be seen through the front window W and the optical wireless communication device 21 can be observed through the front window of the railway vehicle Tb. Note that the location is not limited to above the front window W, and any other location may be used as long as it allows for the transmission and reception of optical signals and does not interfere with the driver's duties in the driver's cab.

The functional configuration of the optical wireless communication device 11 is shown in Figure 3. The optical wireless communication device 11 includes a radio wave wireless communication unit 111, an optical wireless communication unit 112, and a power supply unit 113.

The radio wave wireless communication unit 111 performs wireless communication with the wireless LAN access point 12 using radio waves as the medium. Specifically, it can use wireless LAN (Local Area Network) communication standards such as IEEE 802.11. As shown in Figure 3, the radio wave wireless communication unit 111 includes a radio wave receiving unit 111a, a radio wave transmitting unit 111b, and an antenna 111c.

The radio wave receiving unit 111a receives radio waves transmitted from the wireless LAN access point 12 via the antenna 111c. The radio wave receiving unit 111a extracts data (transmission information) to be transmitted to train set B from, for example, IEEE 802.11 frames contained in the received radio waves, and outputs the extracted data to the optical transmitting unit 112a, which will be described later.

The radio wave transmitter 111b receives data (transmission information) output from the optical receiver 112b (described below), converts the input data into, for example, an IEEE 802.11 frame, and transmits it as radio waves via the antenna 111c to the wireless LAN access point 12.

The optical wireless communication unit 112 performs wireless communication using light, such as infrared light, with the optical wireless communication device 21 installed in train set B. In other words, light is used as a medium to propagate through free space between the railway cars. As shown in Figure 2, the optical wireless communication unit 112 includes an optical transmitter 112a and an optical receiver 112b.

The optical transmitter 112a receives the data (transmission information) output from the radio wave receiver 111a. The optical transmitter 112a has a light source such as a light-emitting diode, converts the input data into an optical signal, and transmits (irradiates) it to the optical wireless communication device 21 as, for example, infrared light.

The optical receiver 112b has a light-receiving element such as a photodiode and receives (receives) infrared light, for example, transmitted from the optical wireless communication device 21. The optical receiver 112b converts the received optical signal into an electrical signal, extracts data (transmission information) to be transmitted to the network within formation A (railroad car Ta), and outputs it to the radio wave transmitter 111b.

The power supply unit 113 receives power, for example, from the railway vehicle Ta, and supplies power to operate each functional block within the optical wireless communication device 11.

The wireless LAN access point 12 is a well-known wireless communication device (also called a wireless LAN base station) installed on the railway vehicle Ta. The wireless LAN access point 12 performs wireless radio communication with wireless communication-capable devices installed on the railway vehicle Ta (optical wireless communication device 11, on-board display devices 13, 14) and functions as a wireless repeater that relays communications between these devices.

In-car display devices 13, 14 are on-board equipment installed, for example, above the entrance and exit doors inside the passenger compartment. For example, in-car display devices 13, 14 display the next stop, advertisements, etc. In-car display devices 13, 14 are equipped with wireless communication devices (also called wireless LAN terminals) for wireless communication with wireless LAN access point 12. In-car display devices 13, 14 are capable of receiving video data, etc. transmitted from wireless LAN access point 12, storing it internally, and displaying it. Note that in-car display devices 13 and 14 have the same configuration, but are designated by different reference numerals for convenience.

The optical wireless communication device 21 is provided in railway car Tb, which is one of the railway cars that make up formation B and is coupled to formation A. The optical wireless communication device 21 is provided opposite the optical wireless communication device 11 provided in railway car Ta of formation A. The optical wireless communication device 21 is installed, for example, in a window of railway car Tb that faces railway car Ta. The functional configuration of the optical wireless communication device 21 is similar to that of the optical wireless communication device 11, so a description thereof will be omitted.

The wireless LAN access point 22 is a well-known wireless communication device installed on the railway vehicle Tb. The wireless LAN access point 22 performs wireless communication via radio waves with wireless communication-capable devices (optical wireless communication device 21, video distribution device 23) installed on the railway vehicle Tb. Note that although the wireless LAN access point 12 and the wireless LAN access point 22 have the same configuration, they are referred to by different reference numerals for convenience.

The video distribution device 23 is an onboard facility installed in the railway vehicle Tb, and stores video images such as advertisements to be distributed to the onboard display devices 13, 14. The video distribution device 23 is equipped with wireless communication equipment for wireless communication with the wireless LAN access point 22. The video distribution device 23 stores video images from a recording medium or the like connected via a wired connection at, for example, a station or depot. Alternatively, the video distribution device 23 may acquire and store video images via wireless communication from a server device or the like outside the train while the train is running or stopped.

Next, the operation of the railway vehicle communication system 1 configured as described above will be described with reference to Figure 1. First, train set A is coupled to train set B in a depot or the like. At this time, the optical wireless communication device 11 and the optical wireless communication device 21 face each other (they can receive each other's emitted light). This connects train set A's network (the wireless network of train set Ta) and train set B's network (the wireless network of train set Tb). Here, the optical wireless communication device 11 is a device belonging to train set A's network, and the optical wireless communication device 21 is a device belonging to train set B's network. The optical wireless communication device 11 is already capable of communicating with other devices, such as the on-board display device 13, on train set A's network. Meanwhile, the optical wireless communication device 21 is already capable of communicating with other devices, such as the video distribution device 23, on train set B's network.

One-to-one communication is carried out between the optical wireless communication device 11 and the optical wireless communication device 21 using optical signals. No particular identification of the other party is performed at this time. In other words, when the optical receiving unit 112b receives a signal that can be demodulated into an electrical signal, communication is carried out regardless of the SSID (Service Set IDentifier) or address of the other network (train set). Therefore, neither network is involved in communication between vehicles. Therefore, no network configuration is required when coupling train sets A and B. For example, video data from the video distribution device 23 sent from the optical wireless communication device 21 to the optical wireless communication device 11 is treated in train set A as data sent by the optical wireless communication device 11 (radio wave transmitting unit 111b).

When trains A and B are coupled as described above, the video data distributed from the video distribution device 23 is sent to the in-car display devices 13 and 14 via the wireless LAN access point 22, the optical wireless communication device 21, the optical wireless communication device 11, and the wireless LAN access point 12, and the video is displayed or stored on the in-car display device 13.

In this embodiment, the onboard equipment includes onboard display devices 13, 14 and video distribution device 23, but is not limited to these. For example, video data of moving and still images captured by an onboard surveillance camera that captures the interior of the passenger compartment, or a vehicle-side surveillance camera installed on the side of the vehicle that captures passengers getting on and off through the entrance and exit doors, may also be transmitted. The recipient of the transmitted information may also be a monitor installed in the driver's cab and monitored by the driver. Alternatively, operation signals for an emergency notification device or door cock may also be transmitted. Information not limited to visual information for passengers and crew members may also be transmitted, such as audio information or control information sent and received between devices.

Although Figure 1 only shows communication between cars at one location and a wireless network for two cars, it can also be applied to trains with three or more cars. A schematic configuration for three or more cars is shown in Figure 4.

Figure 4 shows an example of a train TR consisting of four railway cars T1 to T4. Railway cars T1 to T3 are each equipped with an optical wireless communication device 11, a wireless LAN access point 12, and an in-car display device 13. Railway car T4 is equipped with an optical wireless communication device 11, a wireless LAN access point 12, an in-car display device 13, and a video distribution device 23. Note that the optical wireless communication device 11 and the optical wireless communication device 21 have the same configuration, so they are shown as the optical wireless communication device 11 in Figure 4. Similarly, the wireless LAN access point 12 and the in-car display device 13 are also shown with the reference numerals of the devices with the same configuration.

In Figure 4, the dashed lines drawn inside railway cars T1 to T4 indicate radio wave-based wireless communication, such as IEEE 802.11, while the solid lines between railway cars (between optical wireless communication devices 11) indicate optical wireless communication. Note that in Figure 4, all railway cars making up train TR use wireless LAN and optical wireless communication, but this may be the case for only some of them, such as railway cars T2 and T3.

Furthermore, as shown in FIG. 4, an in-car display device 13 may also be provided in the railway car T4 in which the video distribution device 23 is provided. In this case, the in-car display device 13 acquires video image data via a wireless network within the railway car T4.

As is clear from the above description, the optical wireless communication devices 11 and 21 function as wireless communication devices according to this embodiment.

According to this embodiment, the optical wireless communication device 11 includes a radio wave wireless communication unit 111 that receives radio waves from a wireless LAN access point 12 installed in the railway vehicle Ta and transmits radio waves to the wireless LAN access point 12, and an optical wireless communication unit 112 that irradiates optical signals to a railway vehicle Tb coupled to the railway vehicle Ta and receives optical signals from the railway vehicle Tb. The radio wave wireless communication unit 111 converts transmission information contained in the received radio waves into an electrical signal and outputs it to the optical wireless communication unit 112, and the optical wireless communication unit 112 converts the transmission information into an optical signal and irradiates it to the railway vehicle Tb. Furthermore, the optical wireless communication unit 112 converts transmission information contained in the optical signal received from the railway vehicle Tb into an electrical signal and outputs it to the radio wave wireless communication unit 111, and the radio wave wireless communication unit 111 transmits the transmission information in radio waves to the wireless LAN access point 12.

By configuring the optical wireless communication device 11 as described above, the optical wireless communication unit 112 eliminates the need for wiring to electrical couplers between railway cars. Furthermore, the radio wireless communication unit 111 eliminates the need for additional wired wiring within the railway car. Therefore, network systems can be easily added to existing cars.

In addition, because optical wireless communication is used between vehicles, even if the connected device changes and the network configuration of the entire train changes, no changes to settings are required and communication is possible immediately.

Furthermore, because the optical wireless communication device 11 is installed, for example, on the front window W of the driver's cab of the railway vehicle Ta, it is possible to communicate over the shortest distance with the optical wireless communication device 21 installed on the coupled railway vehicle Tb. This minimizes the impact of external factors such as weather, ensuring reliable communications. Furthermore, because the optical wireless communication device 11 is installed indoors, there is no need for weatherproofing or other measures, making maintenance easier.

The railway vehicle communication system 1 also includes an optical wireless communication device 11, a wireless LAN access point 12, and, for example, an in-car display device 13. The optical wireless communication device 11 performs optical wireless communication with the railway vehicle Tb, and performs radio-wave wireless communication within the railway vehicle Ta. This makes it possible to build a network without installing wired wiring within the railway vehicle Ta. This makes it possible to easily add a network system to an existing vehicle.

In addition, because the in-car display device 13 is installed above the entrance/exit door of the passenger compartment of the railway vehicle Ta, moving image data and the like to be displayed on the in-car display device 13 can be obtained via wireless communication. Therefore, when installing or adding an in-car display device 13 to an existing vehicle, there is no need to lay wired wiring, making it easy to retrofit the in-car display device.

Furthermore, the present invention is not limited to the above-described embodiments. In other words, those skilled in the art can implement various modifications in accordance with conventional knowledge without departing from the gist of the present invention. As long as such modifications still comprise the configuration of the wireless communication device and railway vehicle communication system of the present invention, they will of course be included in the scope of the present invention.

1 Railway vehicle communication system 11 Optical wireless communication device (wireless communication device)
111 Radio wave wireless communication unit 112 Optical wireless communication unit 12 Wireless LAN access point (wireless repeater)
13. In-car display devices (in-car equipment, display devices)
21 Optical wireless communication device (wireless communication device)
22 Wireless LAN access point (wireless repeater)
23 Video distribution device (in-vehicle equipment)
Ta Railway vehicle Tb Railway vehicle (other railway vehicle)

Claims (4)

a radio wave wireless communication unit that receives radio waves from a radio repeater installed in the railway vehicle and transmits radio waves to the radio repeater;
an optical wireless communication unit that irradiates an optical signal to another railway vehicle coupled to the railway vehicle and receives an optical signal from the other railway vehicle,
the radio wave wireless communication unit converts transmission information included in the received radio waves into an electrical signal and outputs the electrical signal to the optical wireless communication unit, and the optical wireless communication unit converts the transmission information into an optical signal and irradiates the optical signal to the other railway vehicle;
the optical wireless communication unit converts transmission information included in the optical signal received from the other railway vehicle into an electrical signal and outputs the electrical signal to the radio wave wireless communication unit, and the radio wave wireless communication unit transmits the transmission information to the radio wave repeater by incorporating the transmission information into radio waves.
A wireless communication device comprising: The wireless communication device described in claim 1 is installed on the front window of the driver's cab of the railway vehicle. a wireless communication device according to claim 1 or 2;
the wireless repeater;
an on-board facility capable of wirelessly communicating with the wireless repeater via radio waves, the on-board facility being provided in the railway vehicle;
and
the wireless communication device performs optical wireless communication with the other railway vehicle and performs radio wave wireless communication within the railway vehicle;
A communication system for railway vehicles. The railway vehicle communication system described in claim 3, characterized in that the onboard equipment includes a display device provided above the entrance door of the passenger compartment of the railway vehicle.