Terrestrial video reception control device

Abstract

An on-board video transmission control device (100) comprises: a public 5G on-board communication unit (101) that performs first wireless communication by means of a first wireless communication scheme; a train wireless on-board communication unit (102) that performs second wireless communication by means of a second wireless communication scheme different from the first wireless communication scheme; a measurement unit (103) that measures the communication quality of the first wireless communication and the communication quality of the second wireless communication; a determination unit (105) that determines whether to use the first wireless communication or the second wireless communication for transmission of video information on the basis of the measurement result from the measurement unit (103); and an output control unit (106) that converts the output format of the video information on the basis of the determination result from the determination unit (105), and outputs the converted video information to the public 5G on-board communication unit (101) or the train wireless on-board communication unit (102).

Description

On-board video transmission control device, ground video reception control device, video transmission system, control circuit, storage medium, on-board video transmission control method, and ground video reception control method

[0001] The present disclosure relates to an on-board video transmission control device that controls video transmission, a ground video reception control device, a video transmission system, a control circuit, a storage medium, an on-board video transmission control method, and a ground video reception control method.

[0002] Conventionally, when a train driver discovers an event that could affect the running of the train, such as a falling rock or tree, he or she would contact the control center that manages train operations using the train radio, and information about the event that the driver discovered would be shared between the driver and the control center dispatcher. However, with communication methods that rely solely on conversation via the train radio, it was difficult to accurately convey the event that the driver discovered to the control center dispatcher.

[0003] To address this issue, Patent Document 1 discloses a technology for a monitoring system in which photographic information, including still images or video images captured by a camera mounted on a train, is transmitted to a monitoring center, and events discovered by the driver are shared between the driver and staff at the monitoring center. Patent Document 1 assumes that the communication method for transmitting the photographic information will be a Long Term Evolution (LTE) or a wireless local area network (LAN) capable of transmitting video images, and these communication methods have higher communication speeds than the communication methods used in conventional train radios.

[0004] International Publication No. 2018 / 173694

[0005] However, according to the above-mentioned conventional technology, communication equipment for communication methods such as LTE and wireless LAN can be either a private network or a public network. However, in the case of a private network, in order to enable communication throughout the entire area where the train runs, it is necessary to install equipment in addition to conventional wireless communication, which is costly and time-consuming. In the case of a public network, if there are areas in the area where the train runs that the public network cannot be used, there will be areas where the photographed information cannot be transmitted. Furthermore, in order for the control center's dispatcher to accurately grasp an event discovered by the driver, video footage is preferable to still images. Generally, transmitting video footage contains more information than transmitting still images, but the above-mentioned conventional technology does not consider when to include still images or video footage in the photographed information.

[0006] The present disclosure has been made in view of the above, and aims to provide an on-board video transmission control device that can transmit appropriate video information depending on the communication situation.

[0007] In order to solve the above-mentioned problems and achieve the object, the on-board video transmission control device of the present disclosure is characterized by comprising: a first on-board communication unit that performs first wireless communication using a first wireless communication method; a second on-board communication unit that performs second wireless communication using a second wireless communication method different from the first wireless communication method; a measurement unit that measures the communication quality of the first wireless communication and the communication quality of the second wireless communication; a determination unit that determines whether to use the first wireless communication or the second wireless communication to transmit video information based on the measurement result of the measurement unit; and an output control unit that converts the output format of the video information based on the determination result of the determination unit and outputs the converted video information to the first on-board communication unit or the second on-board communication unit.

[0008] The on-board video transmission control device according to the present disclosure has the effect of being able to transmit appropriate video information depending on the communication situation.

[0009]

[0010] Below, an on-board video transmission control device, a ground video reception control device, a video transmission system, a control circuit, a storage medium, an on-board video transmission control method, and a ground video reception control method according to embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] Embodiment 1. FIG. 1 is a diagram showing an example of the configuration of a video transmission system 50 according to embodiment 1. The video transmission system 50 includes an on-board video transmission control device 100 and a trackside video reception control device 400. The on-board video transmission control device 100 is mounted on a railway vehicle 10. The on-board video transmission control device 100 is connected to a forward monitoring camera 11a installed at the front of the railway vehicle 10 for capturing images of obstacles 15 that affect the running of the railway vehicle 10. The on-board video transmission control device 100 is also connected to an interior security camera 11b installed in a position capable of capturing images of the passenger compartment of the railway vehicle 10 for capturing images of suspicious individuals 16. In the following description, the forward monitoring camera 11a and the interior security camera 11b will be referred to as camera 11 unless otherwise distinguished. The camera 11 outputs captured video information to the on-board video transmission control device 100. Here, it is assumed that the video information output from the camera 11 to the on-board video transmission control device 100 is in video format. The on-board video transmission control device 100 transmits video information captured by the camera 11 to the wayside equipment 40 by wireless communication using a fifth generation mobile communication system (hereinafter referred to as 5G (5th Generation)) or wireless communication using existing train radio that has been used for some time. The wayside equipment 40 is, for example, a control center that manages the operation of the railway vehicle 10.

[0012] The on-board video transmission control device 100 is connected to a 5G terminal 12 mounted on the railway vehicle 10, and transmits video information via the 5G terminal 12. When the on-board video transmission control device 100 transmits video information via 5G, the wayside equipment 40 receives the video information at a router 41 via a telecommunications carrier facility 20 of a telecommunications carrier providing 5G services, specifically, a 5G base station 22, a 5G core 23, and a router 24. The 5G communication area of ​​the telecommunications carrier facility 20 is the 5G area 21 shown in FIG. 1. The on-board video transmission control device 100 is also connected to a train radio terminal 13 mounted on the railway vehicle 10, and transmits video information via train radio via the train radio terminal 13. When the on-board video transmission control device 100 transmits video information via train radio, the wayside equipment 40 receives the video information at a train radio control station 42 via a train radio base station 30. The train radio communication area of ​​the train radio base station 30 is the train radio area 31 shown in FIG. 1.

[0013] In the wayside equipment 40, when the router 41 or the train radio control station 42 receives video information, the wayside video reception control device 400 converts the video information received by the router 41 or the train radio control station 42 into a format that can be displayed on the display device 43, and displays the video information on the display device 43. This allows a ground operator 44 of the wayside equipment 40 to understand events captured by the camera 11 provided on the railway vehicle 10. Although not shown in Fig. 1, the railway vehicle 10 may use a display device or the like installed in the driver's cab so that an on-board operator 14 such as a driver or conductor can check the video information captured by the camera 11 and output from the camera 11.

[0014] In the video transmission system 50, the communication speed of 5G is faster than the communication speed of train radio. Also, in the video transmission system 50, as shown in FIG. 1 , the 5G area 21 is smaller than the train radio area 31. In communication situations where 5G can be used, the video transmission system 50 can achieve high-capacity, highly reliable, and low-latency wireless communication using 5G. In communication situations where 5G cannot be used but train radio can be used, the video transmission system 50 performs wireless communication using train radio.

[0015] Next, a detailed configuration and operation of the on-board video transmission control device 100 mounted on the railway vehicle 10 will be described. Fig. 2 is a first block diagram showing an example configuration of the on-board video transmission control device 100 according to embodiment 1. The on-board video transmission control device 100 includes a public 5G on-board communication unit 101, a train radio on-board communication unit 102, a measurement unit 103, an on-board memory unit 104, a determination unit 105, and an output control unit 106.

[0016] The public 5G on-board communication unit 101 is a first on-board communication unit that performs first wireless communication using a first wireless communication method. Here, the first wireless communication method is 5G, and the first wireless communication is wireless communication using 5G. The public 5G on-board communication unit 101 transmits the video information converted by the output control unit 106 to the terrestrial video reception control device 400 using the first wireless communication, receives a message transmitted from the terrestrial video reception control device 400 using the first wireless communication, and outputs the message to the determination unit 105.

[0017] The train radio on-board communication unit 102 is a second on-board communication unit that performs second wireless communication by a second wireless communication method different from the first wireless communication method. Here, the second wireless communication method is train radio, and the second wireless communication is wireless communication by train radio. The train radio on-board communication unit 102 transmits the video information converted by the output control unit 106 to the ground video reception control device 400 by the second wireless communication, receives a message transmitted by the ground video reception control device 400 by the second wireless communication, and outputs the message to the determination unit 105.

[0018] The measurement unit 103 measures the communication quality of the first wireless communication in the public 5G on-board communication unit 101 and the communication quality of the second wireless communication in the train radio on-board communication unit 102. The communication quality may be, for example, received power, packet error rate, SNR (Signal to Noise Ratio), etc., but is not limited to these. The measurement unit 103 may measure not only one measurement item but also multiple measurement items for the communication quality. The measurement unit 103 stores the measurement results of the measured communication quality in the on-board memory unit 104 as state information 110.

[0019] The on-board storage unit 104 stores the measurement results of the communication quality measured by the measurement unit 103 as status information 110. Furthermore, the on-board storage unit 104 stores one or more profiles 111 describing image conversion parameters for converting the image information acquired from the camera 11 in the output control unit 106 into an output format for the first wireless communication, as will be described later, and one or more profiles 111 describing image conversion parameters for converting the image information acquired from the camera 11 in the output control unit 106 into an output format for the second wireless communication. Although the illustration is simplified in FIG. 2 , the on-board storage unit 104 actually stores a plurality of profiles 111.

[0020] The determination unit 105 determines whether to use the first wireless communication or the second wireless communication to transmit the video information based on the status information 110 stored in the on-board storage unit 104, i.e., the measurement results of the measurement unit 103. As described above, the communication speed of the first wireless communication, which is 5G, is faster than the communication speed of the second wireless communication, which is train radio. Therefore, the determination unit 105 determines that the output control unit 106 should transmit the converted video information using the public 5G on-board communication unit 101 when the communication quality of the first wireless communication is equal to or higher than the specified communication quality, and determines that the output control unit 106 should transmit the converted video information using the train radio on-board communication unit 102 when the communication quality of the first wireless communication is lower than the specified communication quality and the communication quality of the second wireless communication is equal to or higher than the specified communication quality. The determination unit 105 reads out a profile 111 that matches the determination result from the on-board storage unit 104 and outputs the read profile 111 to the output control unit 106 together with the determination result.

[0021] The output control unit 106 converts the output format of the video information acquired from the camera 11 based on the determination result of the determination unit 105, and outputs the converted video information to the public 5G on-board communication unit 101 or the train radio on-board communication unit 102. Specifically, when the determination unit 105 determines, based on the determination result and profile 111 acquired from the determination unit 105, that the converted video information is to be transmitted using the public 5G on-board communication unit 101, the output control unit 106 converts the video information acquired from the camera 11 into the output format of the first wireless communication and outputs it to the public 5G on-board communication unit 101. Alternatively, when the determination unit 105 determines, based on the determination result and profile 111 acquired from the determination unit 105, that the converted video information is to be transmitted using the train radio on-board communication unit 102, the output control unit 106 converts the video information acquired from the camera 11 into the output format of the second wireless communication and outputs it to the train radio on-board communication unit 102. When the output control unit 106 converts the video information acquired from the camera 11 into the output format for the second wireless communication, it reduces at least one of the resolution and the compression rate compared to when the output control unit 106 converts the video information acquired from the camera 11 into the output format for the first wireless communication.

[0022] Here, the output format of the first wireless communication is video information converted into a moving image format based on specified video conversion parameters, and the output format of the second wireless communication is video information converted into a still image format based on specified video conversion parameters. That is, when the public 5G on-board communication unit 101, which is capable of transmitting larger volumes of data than the train radio on-board communication unit 102, is available, the on-board video transmission control device 100 transmits video information in moving image format to the wayside equipment 40 using the public 5G on-board communication unit 101. When the public 5G on-board communication unit 101 is unavailable and the train radio on-board communication unit 102 is available, the on-board video transmission control device 100 transmits video information in still image format to the wayside equipment 40 using the train radio on-board communication unit 102.

[0023] 3 is a diagram showing an example of a profile 111 stored in the on-board storage unit 104 of the on-board video transmission control device 100 according to the first embodiment. The profile 111 describes various video conversion parameters required when the output control unit 106 converts video information. In the example of FIG. 3, No. 1 and No. 2 are profiles 111 for still images, and No. 3 and No. 4 are profiles 111 for moving images. Furthermore, for each profile 111, video conversion parameters such as resolution, compression method, compression ratio, and frame rate are set. Note that the example shown in FIG. 3 is merely an example, and the on-board storage unit 104 may store three or more profiles 111 for still images, or three or more profiles 111 for moving images. Furthermore, video conversion parameters other than resolution, compression method, compression ratio, and frame rate may be set for each profile 111.

[0024] 4 is a flowchart showing an example of an operation performed by the measurement unit 103 of the on-board video transmission control device 100 according to embodiment 1 to measure the communication quality of the first wireless communication in the public 5G on-board communication unit 101 and the communication quality of the second wireless communication in the train radio on-board communication unit 102. In the on-board video transmission control device 100, the measurement unit 103 starts a timer for counting the timing of measurement (step S101). If a designated time indicating a predetermined measurement period has not elapsed (step S102: No), the measurement unit 103 waits. If the designated time indicating the measurement period has elapsed (step S102: Yes), the measurement unit 103 measures the communication quality of the first wireless communication in the public 5G on-board communication unit 101 and the communication quality of the second wireless communication in the train radio on-board communication unit 102 (step S103). The measurement unit 103 stores the communication quality measurement results as state information 110 in the on-board storage unit 104, i.e., outputs the communication quality measurement results (step S104). The measurement unit 103 resets the timer (step S105) and returns to the operation of step S102. After that, the measurement unit 103 repeats the above operation while the on-board video transmission control device 100 is running.

[0025] 5 is a flowchart showing an example of an operation of the on-board video transmission control device 100 according to the first embodiment to transmit video information to the ground video reception control device 400 of the trackside equipment 40. In the on-board video transmission control device 100, the determination unit 105 acquires the measurement result of the measurement unit 103, i.e., the status information 110 from the on-board storage unit 104 (step S201). The determination unit 105 determines whether the public 5G on-board communication unit 101 is usable (step S202). Specifically, the determination unit 105 determines that the public 5G on-board communication unit 101 is usable if the communication quality of the first wireless communication is equal to or higher than a specified communication quality, and determines that the public 5G on-board communication unit 101 is unusable if the communication quality of the first wireless communication is lower than the specified communication quality. If the public 5G on-board communication unit 101 is usable (step S202: Yes), the determination unit 105 selects a profile 111 corresponding to the first wireless communication from the profiles 111 stored in the on-board storage unit 104 (step S203). The determination unit 105 outputs the selected profile 111 together with the determination result that the public 5G on-board communication unit 101 is usable to the output control unit 106. Based on the determination result and profile 111 obtained from the determination unit 105, the output control unit 106 converts the video information obtained from the camera 11 into the output format of the first wireless communication, i.e., video format (step S204), and outputs it to the public 5G on-board communication unit 101. The public 5G on-board communication unit 101 transmits the video format video information obtained from the output control unit 106 to the wayside equipment 40 (step S205). The on-board video transmission control device 100 then returns to the operation of step S201.

[0026] If the public 5G on-board communication unit 101 is unavailable (step S202: No), the determination unit 105 determines whether the train radio on-board communication unit 102 is available (step S206). Specifically, the determination unit 105 determines that the second wireless communication is available when the communication quality of the second wireless communication is equal to or higher than a specified communication quality, and determines that the second wireless communication is unavailable when the communication quality of the second wireless communication is lower than the specified communication quality. If the train radio on-board communication unit 102 is available (step S206: Yes), the determination unit 105 selects a profile 111 corresponding to the second wireless communication from the profiles 111 stored in the on-board storage unit 104 (step S207). The determination unit 105 outputs the selected profile 111 to the output control unit 106 together with the determination result that the train radio on-board communication unit 102 is available. The output control unit 106 converts the video information acquired from the camera 11 into the output format of the second wireless communication, i.e., the still image format, based on the determination result acquired from the determination unit 105 and the profile 111 (step S208), and outputs the converted video information to the train radio on-board communication unit 102. The train radio on-board communication unit 102 transmits the video information in the still image format acquired from the output control unit 106 to the wayside equipment 40 (step S209). The on-board video transmission control device 100 then returns to the operation of step S201.

[0027] If the determination unit 105 determines that the train radio on-board communication unit 102 is unavailable (step S206: No), the on-board video transmission control device 100 then returns to the operation of step S201. In this way, if the public 5G on-board communication unit 101 is unavailable and the train radio on-board communication unit 102 is unavailable, the on-board video transmission control device 100 does not transmit video information to the wayside equipment 40.

[0028] Next, a detailed configuration and operation of the ground video reception control device 400 installed in the ground facility 40 will be described. The ground video reception control device 400 is a device in the ground facility 40 that manages the operation of the railway vehicle 10, that receives video information from the on-board video transmission control device 100 mounted on the railway vehicle 10 and displays it on a display device 43. Figure 6 is a first block diagram showing an example configuration of the ground video reception control device 400 according to the first embodiment. The ground video reception control device 400 includes a public 5G ground communication unit 401, a train radio ground communication unit 402, and a matching unit 403.

[0029] The public 5G ground communication unit 401 is a first ground communication unit that performs first wireless communication using a first wireless communication method and receives video information from the on-board video transmission control device 100. As in the case of the on-board video transmission control device 100, the first wireless communication method is 5G and the first wireless communication is wireless communication using 5G. The public 5G ground communication unit 401 receives the video information transmitted from the on-board video transmission control device 100 via the first wireless communication and outputs it to the matching unit 403.

[0030] The train radio ground communication unit 402 is a second ground communication unit that performs second wireless communication by a second wireless communication method different from the first wireless communication method and receives video information from the on-board video transmission control device 100. As in the case of the on-board video transmission control device 100, the second wireless communication method is train radio, and the second wireless communication is wireless communication by train radio. The train radio ground communication unit 402 receives video information transmitted by the on-board video transmission control device 100 by the second wireless communication and outputs it to the matching unit 403.

[0031] The matching unit 403 converts the video information received by the first wireless communication by the public 5G ground communication unit 401 or the second wireless communication by the train radio ground communication unit 402 into a format that can be displayed on the display device 43, and outputs the converted video information to the display device 43. Specifically, the matching unit 403 converts the size of the video information according to the screen size, aspect ratio, resolution, etc. of the display device 43, and outputs the converted video information to the display device 43.

[0032] 7 is a flowchart showing an example of the operation of the terrestrial video reception control device 400 according to the first embodiment. In the terrestrial video reception control device 400, the public 5G ground communication unit 401 or the train radio ground communication unit 402 receives video information transmitted from the on-board video transmission control device 100 (step S301). The public 5G ground communication unit 401 or the train radio ground communication unit 402 outputs the received video information to the matching unit 403. The matching unit 403 converts the video information acquired from the public 5G ground communication unit 401 or the train radio ground communication unit 402 into a format that can be displayed on the display device 43 (step S302). The matching unit 403 outputs the converted video information to the display device 43 (step S303).

[0033] FIG. 8 is a sequence diagram showing an example of the operation of the video transmission system 50 according to the first embodiment. In FIG. 8, the train radio base station 30 and the train radio control station 42 are collectively referred to as train radio equipment. This also applies to subsequent similar figures. The camera 11 outputs captured video information to the on-board video transmission control device 100 (step S401). Based on the communication status of the public 5G on-board communication unit 101 and the train radio on-board communication unit 102, the on-board video transmission control device 100 converts the video information acquired from the camera 11 into a video format if the public 5G on-board communication unit 101 is available, and converts the video information acquired from the camera 11 into a still image format if the public 5G on-board communication unit 101 is unavailable but the train radio on-board communication unit 102 is available (step S402).

[0034] When the public 5G on-board communication unit 101 is available, the on-board video transmission control device 100 transmits the converted video information to the ground equipment 40 via the 5G terminal 12, the 5G base station 22, the 5G core 23, and the router 24. In the ground equipment 40, the terrestrial video reception control device 400 converts the video information received by the router 41 into a format that can be displayed on the display device 43, and outputs it to the display device 43. The display device 43 displays the video information acquired from the terrestrial video reception control device 400 (step S403).

[0035] When the public 5G on-board communication unit 101 is unavailable and the train radio on-board communication unit 102 is available, the on-board video transmission control device 100 transmits the converted video information to the wayside equipment 40 via the train radio terminal 13, the train radio base station 30, and the train radio control station 42. In the wayside equipment 40, the ground video reception control device 400 converts the video information received by the train radio control station 42 into a format that can be displayed on the display device 43, and outputs it to the display device 43. The display device 43 displays the video information acquired from the ground video reception control device 400 (step S404).

[0036] In the first embodiment, the case where public 5G provided by a telecommunications carrier is used as the first wireless communication, 5G, has been described, but the present invention is not limited to this. For example, if the railway operator that operates the railway vehicle 10 has its own local 5G facilities, the video transmission system 50 can also use local 5G.

[0037] 9 is a second block diagram showing an example configuration of the on-board video transmission control device 100 according to the first embodiment. The on-board video transmission control device 100 shown in FIG. 9 is obtained by adding a local 5G on-board communication unit 107 to the on-board video transmission control device 100 shown in FIG. 2. The local 5G on-board communication unit 107 is a first on-board communication unit that performs first wireless communication using a first wireless communication method. The local 5G on-board communication unit 107 transmits the video information converted by the output control unit 106 to the terrestrial video reception control device 400 via the first wireless communication, and receives a message transmitted from the terrestrial video reception control device 400 via the first wireless communication and outputs it to the determination unit 105. When both the public 5G on-board communication unit 101 and the local 5G on-board communication unit 107 have a specified communication quality or higher, the on-board video transmission control device 100 may select and use the one with the better communication situation, or when priorities are set in advance for the public 5G on-board communication unit 101 and the local 5G on-board communication unit 107, the one with the higher priority may be used, or both the public 5G on-board communication unit 101 and the local 5G on-board communication unit 107 may be used. Although not shown in the figure, the on-board video transmission control device 100 may also be configured to include only the local 5G on-board communication unit 107 as the first on-board communication unit, and not to include the public 5G on-board communication unit 101.

[0038] In the second embodiment described below and onwards, in order to simplify the explanation, we will explain the case where the on-board video transmission control device 100 only has a public 5G on-board communication unit 101 as the first on-board communication unit, but this is also applicable to the case where the on-board video transmission control device 100 has a public 5G on-board communication unit 101 and a local 5G on-board communication unit 107 as the first on-board communication unit, and to the case where the on-board video transmission control device 100 only has a local 5G on-board communication unit 107 as the first on-board communication unit.

[0039] 10 is a second block diagram showing an example configuration of a terrestrial video reception control device 400 according to embodiment 1. The terrestrial video reception control device 400 shown in FIG. 10 is obtained by adding a local 5G ground communication unit 404 to the terrestrial video reception control device 400 shown in FIG. 6. The local 5G ground communication unit 404 is a first ground communication unit that performs first wireless communication using a first wireless communication method. The local 5G ground communication unit 404 receives video information transmitted from the on-board video transmission control device 100 via the first wireless communication and outputs the video information to the matching unit 403. However, the terrestrial video reception control device 400 uses the public 5G ground communication unit 401 when the on-board video transmission control device 100 uses the public 5G on-board communication unit 101, uses the local 5G ground communication unit 404 when the on-board video transmission control device 100 uses the local 5G on-board communication unit 107, and uses both the public 5G ground communication unit 401 and the local 5G ground communication unit 404 when the on-board video transmission control device 100 uses both the public 5G on-board communication unit 101 and the local 5G on-board communication unit 107. When the matching unit 403 receives the same video information from both the public 5G ground communication unit 401 and the local 5G ground communication unit 404, it only needs to adopt the video information that was received first. Although not shown, the terrestrial video reception control device 400 can also be configured to include only the local 5G ground communication unit 404 as the first ground communication unit, and not to include the public 5G ground communication unit 401.

[0040] In the second embodiment described below and subsequent embodiments, in order to simplify the explanation, we will explain the case where the terrestrial video reception control device 400 only has a public 5G terrestrial communication unit 401 as the first terrestrial communication unit, but this is also applicable to the case where the terrestrial video reception control device 400 has a public 5G terrestrial communication unit 401 and a local 5G terrestrial communication unit 404 as the first terrestrial communication unit, and to the case where the terrestrial video reception control device 400 only has a local 5G terrestrial communication unit 404 as the first terrestrial communication unit.

[0041] In the first embodiment, it is assumed that the on-board video transmission control device 100 acquires video information in video format from the camera 11. As described above, the on-board video transmission control device 100 transmits video information in video format when the video information can be transmitted, i.e., when the public 5G on-board communication unit 101 is available, and transmits video information in still image format when the video information cannot be transmitted but can be transmitted in still image format, i.e., when the public 5G on-board communication unit 101 is unavailable and the train radio on-board communication unit 102 is available. However, the method of transmitting video information in the on-board video transmission control device 100 is not limited to this. For example, when the video information output from the camera 11 is in still image format, the on-board video transmission control device 100 does not need to transmit the video information in video format, i.e., by the public 5G on-board communication unit 101, and may transmit the video information in still image format, i.e., only by the train radio on-board communication unit 102. In addition, if the video information output from the camera 11 can be transmitted at low resolution from the train radio on-board communication unit 102, the on-board video transmission control device 100 may transmit it only using the train radio on-board communication unit 102.

[0042] Next, the hardware configuration of the on-board video transmission control device 100 will be described. In the on-board video transmission control device 100, the public 5G on-board communication unit 101, the train radio on-board communication unit 102, and the local 5G on-board communication unit 107 are communication devices. The on-board storage unit 104 is a memory. The measurement unit 103, the determination unit 105, and the output control unit 106 are realized by processing circuits. The processing circuit may be a processor and memory that executes a program stored in a memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

[0043] FIG. 11 is a diagram illustrating an example of the configuration of a processing circuit 90 that implements the on-board video transmission control device 100 according to the first embodiment when the processing circuit is implemented by a processor 91 and a memory 92. The processing circuit 90 illustrated in FIG. 11 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 processor 91 reads and executes the program stored in the memory 92 to implement each function of the processing circuit 90. That is, the processing circuit 90 includes the memory 92 for storing a program that results in the processing of the on-board video transmission control device 100. This program can also be said to be a program that causes the on-board video transmission control device 100 to execute each function implemented by the processing circuit 90. This program may be provided by a storage medium on which the program is stored, or by other means such as a communication medium.

[0044] The above program can also be said to be a program executed by the on-board video transmission control device 100: a first step in which the public 5G on-board communication unit 101 performs a first wireless communication using a first wireless communication method; a second step in which the train radio on-board communication unit 102 performs a second wireless communication using a second wireless communication method different from the first wireless communication method; a third step in which the measurement unit 103 measures the communication quality of the first wireless communication and the communication quality of the second wireless communication; a fourth step in which the determination unit 105 determines whether the first wireless communication or the second wireless communication is to be used for transmitting the video information based on the measurement result of the measurement unit 103; and a fifth step in which the output control unit 106 converts the output format of the video information based on the determination result of the determination unit 105 and outputs the converted video information to the public 5G on-board communication unit 101 or the train radio on-board communication unit 102.

[0045] 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).

[0046] FIG. 12 is a diagram showing an example of a processing circuit 93 when the processing circuit that realizes the on-board video transmission control device 100 according to the first embodiment is configured with dedicated hardware. The processing circuit 93 shown in FIG. 12 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 realized with dedicated hardware and partially realized with software or firmware. In this way, the processing circuit can realize each of the above-described functions by dedicated hardware, software, firmware, or a combination thereof.

[0047] The hardware configuration of the on-board video transmission control device 100 has been described, but the hardware configuration of the ground video reception control device 400 is also similar. In the ground video reception control device 400, the public 5G ground communication unit 401, the train radio ground communication unit 402, and the local 5G ground communication unit 404 are communication devices. The matching unit 403 is 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.

[0048] As described above, according to the present embodiment, the on-board video transmission control device 100 converts video information acquired from the camera 11 into video format and transmits it from the public 5G on-board communication unit 101 to the wayside equipment 40 when 5G, i.e., the public 5G on-board communication unit 101, is available depending on the communication conditions of 5G and train radio. Alternatively, when 5G, i.e., the public 5G on-board communication unit 101, is unavailable and train radio, i.e., the train radio on-board communication unit 102, is available, the on-board video transmission control device 100 converts video information acquired from the camera 11 into still image format and transmits it from the train radio on-board communication unit 102 to the wayside equipment 40. This allows the on-board video transmission control device 100 to transmit appropriate video information depending on the communication conditions. Furthermore, the on-board video transmission control device 100 can reduce transmission delays when the line speed changes suddenly, compared to when the video transmission method, such as the frame rate, is changed depending on the line conditions using RTP (Real-time Transport Protocol) / RTCP (RTP Control Protocol).

[0049] Embodiment 2 In the first embodiment, when the output control unit 106 of the on-board video transmission control device 100 changes the conversion method of the video information, a time lag may occur in the output of the video information. In the second embodiment, a method for reducing the time lag in the output of the video information from the output control unit 106 when the output control unit 106 of the on-board video transmission control device 100 changes the conversion method of the video information will be described.

[0050] In the second embodiment, the configuration of the video transmission system 50 is the same as the configuration of the video transmission system 50 in the first embodiment shown in Fig. 1. Furthermore, the configuration of the on-board video transmission control device 100 is the same as the configuration of the on-board video transmission control device 100 in the first embodiment shown in Fig. 2. Furthermore, the configuration of the terrestrial video reception control device 400 is the same as the configuration of the terrestrial video reception control device 400 in the first embodiment shown in Fig. 6. In the second embodiment, the operation of the output control unit 106 provided in the on-board video transmission control device 100 is different.

[0051] In the second embodiment, the output control unit 106 converts the video information acquired from the camera 11 into the output format of the first wireless communication and also into the output format of the second wireless communication based on the profile 111 acquired from the determination unit 105. Based on the determination result acquired from the determination unit 105, the output control unit 106 outputs the first video information after being converted into the output format of the first wireless communication to the public 5G on-board communication unit 101, or outputs the second video information after being converted into the output format of the second wireless communication to the train radio on-board communication unit 102.

[0052] 13 is a first block diagram showing an example of the configuration of the output control unit 106 included in the on-board video transmission control device 100 according to Embodiment 2. The output control unit 106 includes a conversion unit 121 and a selection unit 122.

[0053] Based on profile 111 acquired from determination unit 105, conversion unit 121 converts the video information acquired from camera 11 into the output format of the first wireless communication, i.e., video information in a moving image format, and also converts the video information acquired from camera 11 into the output format of the second wireless communication, i.e., video information in a still image format. Conversion unit 121 outputs the video information in the moving image format and the video information in the still image format to selection unit 122.

[0054] The selection unit 122 acquires video information in moving image format and video information in still image format from the conversion unit 121. Based on the determination result acquired from the determination unit 105, if the determination unit 105 determines that the converted video information is to be transmitted using the public 5G on-board communication unit 101, the selection unit 122 outputs video information in moving image format to the public 5G on-board communication unit 101, and if the determination unit 105 determines that the converted video information is to be transmitted using the train radio on-board communication unit 102, the selection unit 122 outputs video information in still image format to the train radio on-board communication unit 102.

[0055] As described above, in the second embodiment, the determination unit 105 outputs the profile 111 to the conversion unit 121 and outputs the determination result to the selection unit 122. The output control unit 106 constantly generates video information in moving image format and video information in still image format regardless of the determination result of the determination unit 105, and selects and outputs the video information in moving image format or the video information in still image format based on the determination result of the determination unit 105. When changing the video information to be output, the output control unit 106 simply changes the video information to be selected based on the determination result of the determination unit 105 in the second embodiment. Therefore, compared to the case where the method of converting the video information itself is changed based on the determination result of the determination unit 105 as in the first embodiment, the time lag in the output of the video information from the output control unit 106 can be reduced.

[0056] 14 is a flowchart showing an example of an operation of the on-board video transmission control device 100 according to the second embodiment to transmit video information to the ground video reception control device 400 of the trackside equipment 40. In the on-board video transmission control device 100, the determination unit 105 acquires the measurement result of the measurement unit 103, i.e., the status information 110 from the on-board storage unit 104 (step S501). The determination unit 105 also reads, from the on-board storage unit 104, a profile 111 for when the public 5G on-board communication unit 101 is available and a profile 111 for when the train radio on-board communication unit 102 is available, and outputs the read profiles 111 to the conversion unit 121 of the output control unit 106. Based on the acquired profile 111, the conversion unit 121 of the output control unit 106 converts the video information acquired from the camera 11 into video information in the output format of the first wireless communication, i.e., video information in a moving image format, and converts the video information acquired from the camera 11 into video information in the output format of the second wireless communication, i.e., video information in a still image format. The conversion unit 121 outputs the video information in the moving image format and the video information in the still image format to the selection unit 122 .

[0057] The determination unit 105 determines whether the public 5G on-board communication unit 101 is available (step S502). Specifically, the determination unit 105 determines that the public 5G on-board communication unit 101 is available when the communication quality of the first wireless communication is equal to or higher than a specified communication quality, and determines that the public 5G on-board communication unit 101 is unavailable when the communication quality of the first wireless communication is lower than the specified communication quality. If the public 5G on-board communication unit 101 is available (step S502: Yes), the determination unit 105 outputs a determination result that the public 5G on-board communication unit 101 is available to the selection unit 122 of the output control unit 106. Based on the determination result obtained from the determination unit 105, the selection unit 122 of the output control unit 106 selects video information in video format from the video information obtained from the conversion unit 121 (step S503) and outputs the selected video information to the public 5G on-board communication unit 101. The public 5G on-board communication unit 101 transmits the video information in video format obtained from the output control unit 106 to the ground equipment 40 (step S504). The on-board video transmission control device 100 then returns to the operation of step S501.

[0058] If the public 5G on-board communication unit 101 is unavailable (step S502: No), the determination unit 105 determines whether the train radio on-board communication unit 102 is available (step S505). Specifically, the determination unit 105 determines that the second wireless communication is available when the communication quality of the second wireless communication is equal to or higher than a specified communication quality, and determines that the second wireless communication is unavailable when the communication quality of the second wireless communication is lower than the specified communication quality. If the train radio on-board communication unit 102 is available (step S505: Yes), the determination unit 105 outputs a determination result that the train radio on-board communication unit 102 is available to the selection unit 122 of the output control unit 106. Based on the determination result obtained from the determination unit 105, the selection unit 122 of the output control unit 106 selects video information in a still image format from the video information obtained from the conversion unit 121 (step S506), and outputs the selected video information to the train radio on-board communication unit 102. The train radio on-board communication unit 102 transmits the video information in the still image format acquired from the output control unit 106 to the trackside equipment 40 (step S507). The on-board video transmission control device 100 then returns to the operation of step S501.

[0059] If the determination unit 105 determines that the train radio on-board communication unit 102 is unavailable (step S505: No), the on-board video transmission control device 100 then returns to the operation of step S501. In this way, if the public 5G on-board communication unit 101 is unavailable and the train radio on-board communication unit 102 is unavailable, the on-board video transmission control device 100 does not transmit video information to the wayside equipment 40.

[0060] In the second embodiment, the function of the conversion unit 121 included in the output control unit 106 can also be provided as a separate device outside the on-board video transmission control device 100. FIG. 15 is a second block diagram showing a configuration example of the output control unit 106 included in the on-board video transmission control device 100 according to the second embodiment. The output control unit 106 includes a selection unit 122. A conversion unit 17 is also connected to the on-board video transmission control device 100. Although not shown, the conversion unit 17 is assumed to be mounted on the railway vehicle 10, similar to the on-board video transmission control device 100. The function of the conversion unit 17 is the same as the function of the conversion unit 121 described above. Since the conversion unit 17 is located outside the on-board video transmission control device 100, when updating, for example, adding or changing the conversion method for converting video information acquired from the camera 11, this can be done more easily than in the configuration shown in FIG. 13. In addition, even in the on-board video transmission control device 100 of embodiment 1, it is possible for the output control unit 106 to have the function of converting video information as a separate device outside the on-board video transmission control device 100, but in this case, the on-board video transmission control device 100 does not need to be equipped with the output control unit 106.

[0061] As described above, according to this embodiment, in the on-board video transmission control device 100, the output control unit 106 always generates video information in moving image format and video information in still image format regardless of the determination result of the determination unit 105, and selects and outputs the video information in moving image format or the video information in still image format based on the determination result of the determination unit 105. As a result, compared to the first embodiment, the output control unit 106 can reduce the time lag in outputting video information from the output control unit 106 when changing the conversion method for the video information to be output.

[0062] Third Embodiment In a third embodiment, a case will be described in which an on-board operator 14 of the railway vehicle 10 selects a profile 111 to be used by the output control unit 106.

[0063] 16 is a diagram illustrating an example of the operation of the on-board video transmission control device 100 according to the third embodiment. The on-board operator 14 of the railway vehicle 10 selects a requested profile 111 from the profiles 111 stored in the on-board storage unit 104 of the on-board video transmission control device 100. The determination unit 105 outputs the profile 111 selected by the on-board operator 14 aboard the railway vehicle 10 to the output control unit 106. This enables the output control unit 106 to convert the video information acquired from the camera 11 using the profile 111 selected by the on-board operator 14. The on-board operator 14 may select the profile 111 via a terminal (not shown) capable of communicating with the on-board video transmission control device 100, or may select the profile 111 by directly operating the on-board video transmission control device 100 if the on-board video transmission control device 100 is capable of accepting operations from the on-board operator 14.

[0064] As described above, the on-board storage unit 104 stores the profiles 111 shown in FIG. 3 . For example, if the on-board operator 14 is currently transmitting video information in a moving image format converted using the video conversion parameters of profile No. 3 111 and wants to transmit video information in a moving image format with higher image quality, the on-board operator 14 selects profile No. 4 111. This allows the on-board video transmission control device 100 to transmit video information in a moving image format with higher image quality than before the on-board operator 14 selected profile 111. Similarly, for example, if the on-board operator 14 is currently transmitting video information in a still image format converted using the video conversion parameters of profile No. 1 111 and wants to transmit video information in a still image format with higher image quality, the on-board operator 14 selects profile No. 2 111. This allows the on-board video transmission control device 100 to transmit video information in a still image format with higher image quality than before the on-board operator 14 selected profile 111. In addition, the on-board operator 14 may select the profile 111 either before the output control unit 106 of the on-board video transmission control device 100 starts converting the video information, or after the output control unit 106 of the on-board video transmission control device 100 starts converting the video information.

[0065] As described above, according to this embodiment, the on-board video transmission control device 100 can change the image quality of the video information to be transmitted, depending on the selection of the on-board operator 14 of the railway vehicle 10. This allows the on-board video transmission control device 100 to transmit video information of the image quality requested by the on-board operator 14 to the track video reception control device 400.

[0066] Fourth Embodiment In a fourth embodiment, a case will be described in which a ground operator 44 of the ground facility 40 selects a profile 111 to be used in the output control unit 106.

[0067] 17 is a diagram illustrating an example of the operation of the on-board video transmission control device 100 according to the fourth embodiment. The ground operator 44 of the on-board equipment 40 operates the ground video reception control device 400 using the display device 43 as an operation terminal, and selects a desired profile 111 from the profiles 111 stored in the on-board storage unit 104 of the on-board video transmission control device 100. The determination unit 105 acquires an instruction from the ground operator 44 to select the profile 111 from the ground video reception control device 400 of the on-board equipment 40 via the public 5G on-board communication unit 101 or the train radio on-board communication unit 102. The determination unit 105 outputs the profile 111 selected by the ground operator 44 of the on-board equipment 40 to the output control unit 106. This enables the output control unit 106 to convert the video information acquired from the camera 11 using the profile 111 selected by the ground operator 44. In addition, the timing at which the ground operator 44 selects the profile 111 may be before the output control unit 106 of the on-board video transmission control device 100 starts converting the video information, or after the output control unit 106 of the on-board video transmission control device 100 starts converting the video information.

[0068] Fig. 18 is a block diagram showing an example of the configuration of a terrestrial video reception control device 400 according to embodiment 4. The terrestrial video reception control device 400 of embodiment 4 shown in Fig. 18 is obtained by adding a terrestrial storage unit 405, a control unit 406, and a message generation unit 407 to the terrestrial video reception control device 400 of embodiment 1 shown in Fig. 6.

[0069] The ground storage unit 405 stores one or more profiles 111 describing video conversion parameters used by the on-board video transmission control device 100 to convert the video information acquired by the on-board video transmission control device 100 from the camera 11 into an output format for the first wireless communication, and one or more profiles 111 describing video conversion parameters used by the on-board video transmission control device 100 to convert the video information acquired by the on-board video transmission control device 100 from the camera 11 into an output format for the second wireless communication. Although the illustration is simplified in FIG. 18 , the ground storage unit 405 actually stores multiple profiles 111. The profiles 111 are similar to the profile 111 shown in FIG. 3 and stored in the on-board storage unit 104 of the on-board video transmission control device 100. That is, the on-board video transmission control device 100 and the ground video reception control device 400 store a common profile 111. The ground storage unit 405 also stores railway vehicle information 410, which is information about multiple railway vehicles 10 whose operation is managed by the ground equipment 40. The ground storage unit 405 acquires and stores the railway vehicle information 410, for example, from a server (not shown) that actually manages the operation of the railway vehicle 10 in the ground facility 40. The railway vehicle information 410 includes, for example, but is not limited to, identification information for identifying each railway vehicle 10, the running position of each railway vehicle 10, and identification information of a base station to which each railway vehicle 10 is connected for wireless communication.

[0070] The control unit 406 acquires operation information received by the display device 43 from the ground operator 44 of the ground equipment 40, and selects the profile 111 to be used by the on-board video transmission control device 100 from the ground storage unit 405 based on the operation information. The operation information is information about the profile 111 requested by the ground operator 44, received by the display device 43 from the ground operator 44. The control unit 406 outputs the selected profile 111 to the message generation unit 407. Note that since the profile 111 is similar to the profile 111 shown in FIG. 3 , the control unit 406 can determine whether the selected profile 111 is in a video format or a still image format. Therefore, the control unit 406 may instruct the message generation unit 407 whether the message should be output to the public 5G ground communication unit 401 or the train radio ground communication unit 402. Specifically, if the selected profile 111 is in video format, the control unit 406 instructs the public 5G ground communication unit 401 to output the message, and if the selected profile 111 is in still image format, the control unit 406 instructs the train radio ground communication unit 402 to output the message.

[0071] The message generation unit 407 acquires the profile 111 from the control unit 406. The message generation unit 407 generates a message instructing the on-board video transmission control device 100 on the profile 111 to be used, and outputs the generated message to the public 5G ground communication unit 401 or the train radio ground communication unit 402. The message generation unit 407 may include, in the generated message, video conversion parameters corresponding to the profile 111 actually selected by the control unit 406, or may include only information such as a number for identifying each profile 111, for example, No. 1 shown in FIG. 3 . If the message generation unit 407 has received an instruction from the control unit 406 regarding the output destination of the message, the message generation unit 407 outputs the message in accordance with the instruction from the control unit 406. Note that, although not shown, if the message generation unit 407 has acquired information from the matching unit 403 regarding whether the video information was received by the public 5G ground communication unit 401 or the train radio ground communication unit 402, the message generation unit 407 may determine the output destination of the message based on the information acquired from the matching unit 403.

[0072] In the ground video reception control device 400, the public 5G ground communication unit 401 transmits a message obtained from the message generation unit 407 to the on-board video transmission control device 100 via a first wireless communication, or the train radio ground communication unit 402 transmits a message obtained from the message generation unit 407 to the on-board video transmission control device 100 via a second wireless communication.

[0073] 19 is a sequence diagram showing an example of the operation of the video transmission system 50 according to the fourth embodiment. The display device 43 receives the selection of the profile 111 requested by the ground operator 44 (step S601). The display device 43 outputs the information on the profile 111 requested by the ground operator 44 received from the ground operator 44 as operation information to the terrestrial video reception control device 400. The control unit 406 of the terrestrial video reception control device 400 acquires the operation information from the display device 43 (step S602). The terrestrial video reception control device 400 generates a message indicating the profile 111 requested by the ground operator 44 to the on-board video transmission control device 100 through the operations described above.

[0074] When the public 5G on-board communication unit 101 is available in the on-board video transmission control device 100, that is, when the message generation unit 407 of the terrestrial video reception control device 400 transmits a message from the public 5G ground communication unit 401, the public 5G ground communication unit 401 of the terrestrial video reception control device 400 transmits the message to the on-board video transmission control device 100 via the router 41, the router 24, the 5G core 23, the 5G base station 22, and the 5G terminal 12. The on-board video transmission control device 100 outputs the message received by the public 5G on-board communication unit 101 to the determination unit 105. The determination unit 105 outputs the profile 111 selected by the ground operator 44 of the ground equipment 40 to the output control unit 106. The subsequent operations are the same as those in the third embodiment. This allows the on-board video transmission control device 100 to update the profile 111 used to convert video information (step S603).

[0075] When the public 5G on-board communication unit 101 is unavailable in the on-board video transmission control device 100 and the train radio on-board communication unit 102 is available, i.e., when the message generation unit 407 of the ground video reception control device 400 transmits a message from the train radio ground communication unit 402, the train radio ground communication unit 402 of the ground video reception control device 400 transmits the message to the on-board video transmission control device 100 via the train radio control station 42, the train radio base station 30, and the train radio terminal 13. The on-board video transmission control device 100 outputs the message received by the train radio on-board communication unit 102 to the determination unit 105. The determination unit 105 outputs the profile 111 selected by the ground operator 44 of the ground equipment 40 to the output control unit 106. The subsequent operations are the same as those in the third embodiment. As a result, the on-board video transmission control device 100 can update the profile 111 used for converting video information (step S604).

[0076] For example, if the ground operator 44 is currently transmitting video information in a video format converted using the video conversion parameters of profile 111 No. 3 and requests video information in a video format with higher image quality, the ground operator 44 selects profile 111 No. 4. This allows the on-board video transmission control device 100 to transmit video information in a video format with higher image quality than before the ground operator 44 selected profile 111. Similarly, if the ground operator 44 is currently transmitting video information in a still image format converted using the video conversion parameters of profile 111 No. 1 and requests video information in a still image format with higher image quality, the ground operator 44 selects profile 111 No. 2. This allows the on-board video transmission control device 100 to transmit video information in a still image format with higher image quality than before the ground operator 44 selected profile 111. In addition, the timing at which the ground operator 44 selects the profile 111 may be before the output control unit 106 of the on-board video transmission control device 100 starts converting the video information, or after the output control unit 106 of the on-board video transmission control device 100 starts converting the video information.

[0077] The hardware configuration of the terrestrial video reception control device 400 according to embodiment 4 will now be described. In the terrestrial video reception control device 400, the terrestrial storage unit 405 is a memory. The control unit 406 and message generation unit 407 are realized by processing circuits. The processing circuit may be a processor and memory that executes a program stored in memory, or may be dedicated hardware.

[0078] As described above, according to this embodiment, the on-board video transmission control device 100 can change the image quality of the video information to be transmitted, depending on the selection made by the ground operator 44 of the trackside equipment 40. This allows the on-board video transmission control device 100 to transmit video information of the image quality requested by the ground operator 44 to the ground video reception control device 400.

[0079] Embodiment 5. In Embodiment 4, the on-board video transmission control device 100 changed the image quality of the transmitted video information, etc., depending on the selection of the wayside operator 44. As described above, it is generally assumed that the wayside operator 44 wants to check the video information in detail, so the image quality of the video information will be high. In order to increase the image quality of the video information, the amount of transmitted video information needs to be increased. However, if the wayside equipment 40 does not have sufficient communication capacity, it may not be possible to increase the amount of video information. In Embodiment 5, a case will be described in which the wayside video reception control device 400 transmits a message to lower the image quality of the video information or a message to stop the transmission of video information to on-board video transmission control devices 100 mounted on railway vehicles 10 other than the railway vehicle 10 mounted with the on-board video transmission control device 100 whose video information profile 111 was updated in Embodiment 4.

[0080] In the fifth embodiment, the railway vehicle 10 equipped with the on-board video transmission control device 100 for which the image quality of the video information is to be enhanced is referred to as railway vehicle 10a, and the railway vehicle 10 other than the railway vehicle 10a equipped with the on-board video transmission control device 100 for which the image quality of the video information is to be enhanced is referred to as railway vehicle 10b. It is assumed that the on-board video transmission control devices 100 equipped in the railway vehicles 10a and 10b have the same functions. FIG. 20 is a diagram showing an example of an on-board video transmission control device 100 to which a track-based video reception control device 400 according to the fifth embodiment sends a message to the on-board video transmission control device 100 of the railway vehicle 10a, by performing the same operation as that described in the fourth embodiment. Furthermore, the track-based video reception control device 400 sends a message to the on-board video transmission control device 100 of the railway vehicle 10a, instructing the profile 111 for enhancing the image quality of the video information, or a message instructing the stop of the transmission of the video information, to the on-board video transmission control device 100 of the railway vehicle 10b, which shares the communication bandwidth with the railway vehicle 10a. This allows the ground video reception control device 400 to ensure a communication capacity for the on-board video transmission control device 100 of the railway vehicle 10a to transmit high-quality video information.

[0081] In the trackside video reception control device 400, when the control unit 406 selects a profile 111 for improving the image quality of the video information to be output to the on-board video transmission control device 100 of the first railcar 10a in response to the operation information, i.e., for higher image quality, the control unit 406 selects a profile 111 for lowering the image quality of the video information to be output to the on-board video transmission control device 100 of the second railcar other than the first railcar, i.e., for lowering the image quality, or determines to stop transmission of the video information, based on the railcar information 410. For example, when the on-board video transmission control device 100 of the railcar 10a is using profile No. 1 and is to change it to profile No. 2, the control unit 406 changes the on-board video transmission control device 100 of the railcar 10b to profile No. 1 if it is using profile No. 2. Similarly, the control unit 406 selects a profile 111 for lowering the image quality of the video information to be output to the on-board video transmission control device 100 of the second railcar other than the first railcar, i.e., for lowering the image quality, or determines to stop transmission of the video information, based on the railcar information 410. For example, when the on-board video transmission control device 100 of the railcar 10a is using profile No. 1 and is to change it to profile No. 2, the control unit 406 changes it to profile No. 1 if the on-board video transmission control device 100 of the railcar 10b is using profile No. 2. In the case where the No. 3 profile 111 is currently in use and is to be changed to the No. 4 profile 111, if the on-board video transmission control device 100 of the railway car 10b is using the No. 4 profile 111, the on-board video transmission control device 100 will change to the No. 3 profile 111.

[0082] Regarding a method of determining a railway vehicle 10b that shares a communication band with the railway vehicle 10a, when the on-board video transmission control device 100 and the ground video reception control device 400 are communicating via 5G, the control unit 406 may, for example, select the railway vehicle 10b as the railway vehicle 10 traveling near the railway vehicle 10a based on the railway vehicle information 410 from the traveling position information of the railway vehicles 10a and 10b, or may select the railway vehicle 10b as the railway vehicle 10 with the same 5G connection cell ID (IDentifier), or may select the railway vehicle 10b as the railway vehicle 10 that shares a communication line between the public 5G network router 24 and the router 41 of the ground equipment 40. Furthermore, regarding a method of determining a railway vehicle 10b that shares a communication band with the railway vehicle 10a, when the on-board video transmission control device 100 and the ground video reception control device 400 are communicating via train radio, the control unit 406 may, for example, select the railway vehicle 10b as the railway vehicle 10 connected to the same train radio base station 30 as the railway vehicle 10a based on the railway vehicle information 410.

[0083] When the video information being transmitted by the on-board video transmission control device 100 of the railway car 10b is in moving image format and the lowest image quality profile 111 is already in use, the control unit 406 may stop the transmission of the video information or may change the video information to a still image format. Furthermore, when the video information being transmitted by the on-board video transmission control device 100 of the railway car 10b is in still image format and the lowest image quality profile 111 is already in use, the control unit 406 stops the transmission of the video information.

[0084] The control unit 406 may receive and determine the selection of the railway vehicle 10b and the profile 111 to be used in the railway vehicle 10b from the ground operator 44.

[0085] The message generation unit 407 generates a message to the on-board video transmission control device 100 of the railway vehicle 10b, instructing it to use a profile 111 to lower the image quality of the video information to be output, i.e., to lower the image quality, or a message instructing it to stop transmitting the video information, and outputs the generated message to the public 5G ground communication unit 401 or the train radio ground communication unit 402.

[0086] In the on-board video transmission control device 100 of the railway car 10a and the on-board video transmission control device 100 of the railway car 10b, the determination unit 105 acquires an instruction to select a profile 111 from the ground video reception control device 400 of the ground equipment 40 via the public 5G on-board communication unit 101 or the train radio on-board communication unit 102. The determination unit 105 outputs the profile 111 selected by the ground equipment 40 to the output control unit 106.

[0087] 21 is a sequence diagram showing an example of the operation when video information is being transmitted in video format in the video transmission system 50 according to embodiment 5. The on-board video transmission control device 100 of the railway car 10b converts the video information acquired from the camera 11 into video format and transmits it to the wayside equipment 40 (step S701). The on-board video transmission control device 100 of the railway car 10a converts the video information acquired from the camera 11 into video format and transmits it to the wayside equipment 40 (step S702). The operation of step S701 in which the on-board video transmission control device 100 of the railway car 10b transmits the video information and the operation of step S702 in which the on-board video transmission control device 100 of the railway car 10a transmits the video information are the same as the operation of step S403 shown in FIG. 8.

[0088] The display device 43 receives a selection of the profile 111 requested by the ground operator 44 for the video information transmitted from the on-board video transmission control device 100 of the railway vehicle 10a (step S703). The display device 43 outputs the information on the profile 111 requested by the ground operator 44 received from the ground operator 44 as operation information to the ground video reception control device 400. The control unit 406 of the ground video reception control device 400 acquires the operation information from the display device 43 (step S704). The ground video reception control device 400 selects the other railway vehicle 10b through the operation described above (step S705). The message generation unit 407 of the ground video reception control device 400 generates a message indicating the profile 111 requested by the ground operator 44 for the on-board video transmission control device 100 of the railway vehicle 10a, and a message indicating the profile 111 for the on-board video transmission control device 100 of the railway vehicle 10b.

[0089] The public 5G ground communication unit 401 of the ground video reception control device 400 transmits a message for the on-board video transmission control device 100 of the railway vehicle 10b to the on-board video transmission control device 100 of the railway vehicle 10b via the router 41, the router 24, the 5G core 23, the 5G base station 22, and the 5G terminal 12 (step S706). The on-board video transmission control device 100 of the railway vehicle 10b outputs the message received by the public 5G on-board communication unit 101 to the determination unit 105. The determination unit 105 outputs the profile 111 set in the ground equipment 40 to the output control unit 106. The subsequent operations are the same as those in the third and fourth embodiments. As a result, the on-board video transmission control device 100 of the railway vehicle 10b can update the profile 111 used to convert video information (step S707). The on-board video transmission control device 100 of the railway vehicle 10b uses the updated profile 111 to convert the video information acquired from the camera 11 into video format and transmits it to the ground equipment 40 (step S708).

[0090] The public 5G ground communication unit 401 of the ground video reception control device 400 transmits a message to the on-board video transmission control device 100 of the railway vehicle 10a via the router 41, the router 24, the 5G core 23, the 5G base station 22, and the 5G terminal 12 to the on-board video transmission control device 100 of the railway vehicle 10a (step S709). The on-board video transmission control device 100 of the railway vehicle 10a outputs the message received by the public 5G on-board communication unit 101 to the determination unit 105. The determination unit 105 outputs the profile 111 selected by the ground operator 44 of the wayside equipment 40 to the output control unit 106. The subsequent operations are the same as those in the third and fourth embodiments. As a result, the on-board video transmission control device 100 of the railway vehicle 10a can update the profile 111 used to convert video information (step S710). The on-board video transmission control device 100 of the railway vehicle 10a uses the updated profile 111 to convert the video information acquired from the camera 11 into video format and transmits it to the ground equipment 40 (step S711).

[0091] 22 is a sequence diagram showing an example of the operation when video information is being transmitted in still image format in the video transmission system 50 according to embodiment 5. The on-board video transmission control device 100 of the railway vehicle 10b converts the video information acquired from the camera 11 into still image format and transmits it to the wayside equipment 40 (step S801). The on-board video transmission control device 100 of the railway vehicle 10a converts the video information acquired from the camera 11 into still image format and transmits it to the wayside equipment 40 (step S802). The operation of step S801 in which the on-board video transmission control device 100 of the railway vehicle 10b transmits the video information and the operation of step S802 in which the on-board video transmission control device 100 of the railway vehicle 10a transmits the video information are the same as the operation of step S404 shown in FIG. 8.

[0092] The display device 43 receives a selection of the profile 111 requested by the ground operator 44 for the video information transmitted from the on-board video transmission control device 100 of the railway vehicle 10a (step S803). The display device 43 outputs the information on the profile 111 requested by the ground operator 44 received from the ground operator 44 as operation information to the ground video reception control device 400. The control unit 406 of the ground video reception control device 400 acquires the operation information from the display device 43 (step S804). The ground video reception control device 400 selects the other railway vehicle 10b through the operation described above (step S805). The message generation unit 407 of the ground video reception control device 400 generates a message indicating the profile 111 requested by the ground operator 44 to the on-board video transmission control device 100 of the railway vehicle 10a, and a message instructing the on-board video transmission control device 100 of the railway vehicle 10b to stop transmitting video information.

[0093] The train radio ground communication unit 402 of the ground video reception control device 400 transmits a message to the on-board video transmission control device 100 of railway car 10b via the train radio control station 42, the train radio base station 30, and the train radio terminal 13 to the on-board video transmission control device 100 of railway car 10b (step S806). The on-board video transmission control device 100 of railway car 10b outputs the message received by the train radio on-board communication unit 102 to the determination unit 105. The determination unit 105 instructs the output control unit 106 to stop transmitting video information. This allows the on-board video transmission control device 100 of railway car 10b to stop transmitting video information (step S807).

[0094] The train radio ground communication unit 402 of the ground video reception control device 400 transmits a message for the on-board video transmission control device 100 of the railway car 10a to the on-board video transmission control device 100 of the railway car 10a via the train radio control station 42, the train radio base station 30, and the train radio terminal 13 (step S808). The on-board video transmission control device 100 of the railway car 10a outputs the message received by the train radio on-board communication unit 102 to the determination unit 105. The determination unit 105 outputs the profile 111 selected by the ground operator 44 of the wayside equipment 40 to the output control unit 106. The subsequent operations are the same as those in the third and fourth embodiments. As a result, the on-board video transmission control device 100 of the railway car 10a can update the profile 111 used for converting video information (step S809). The on-board video transmission control device 100 of the railway vehicle 10a uses the updated profile 111 to convert the video information acquired from the camera 11 into video format and transmits it to the ground equipment 40 (step S810).

[0095] Although the fifth embodiment has been described in a format applied to the fourth embodiment, the present invention is not limited to this. The fifth embodiment can also be applied to the third embodiment. For example, when the image quality of the video information transmitted from the on-board video transmission control device 100 of the railway vehicle 10a is changed from low image quality to high image quality, the trackside video reception control device 400 detects the change in image quality of the video information in the matching unit 403. Although not shown in the figure, when the control unit 406 receives a notification from the matching unit 403 that a change in image quality of the video information has been detected, the control unit 406 can thereafter perform the same operation as when operation information is acquired from the display device 43, i.e., the operation described in the fifth embodiment.

[0096] As described above, according to this embodiment, when the image quality of the video information transmitted from the on-board video transmission control device 100 of the railway car 10a is increased, the ground video reception control device 400 reduces the image quality of the video information transmitted from the on-board video transmission control device 100 of the other railway car 10b, or stops the transmission of video information from the on-board video transmission control device 100 of the other railway car 10b. This allows the ground video reception control device 400 to ensure communication capacity in response to an increase in the amount of information caused by the increased image quality of the video information transmitted from the on-board video transmission control device 100 of the railway car 10a.

[0097] Embodiment 6 In embodiment 3, the on-board video transmission control device 100 changes the image quality of the video information by updating the profile 111 to be used in response to a request from the on-board operator 14, and in embodiment 4, it changes the image quality of the video information by updating the profile 111 to be used in response to a request from the ground operator 44, but the method of updating the profile 111 to be used is not limited to these. The on-board video transmission control device 100 may update the profile 111 to be used based on the analysis results of the on-board video transmission control device 100 or the ground video reception control device 400 analyzing the video information.

[0098] First, a case where the on-board video transmission control device 100 analyzes video information will be described. Fig. 23 is a block diagram showing an example of the configuration of the on-board video transmission control device 100 according to embodiment 6. The on-board video transmission control device 100 of embodiment 6 shown in Fig. 23 is obtained by adding an on-board image analysis unit 108 to the on-board video transmission control device 100 of embodiment 1 shown in Fig. 2.

[0099] The on-board image analysis unit 108 analyzes the video information acquired from the camera 11, and when a specified object such as an obstacle 15 or a suspicious person 16 is detected in the video information, the on-board image analysis unit 108 instructs the determination unit 105 to change the profile 111. For example, the on-board image analysis unit 108 stores information on the shapes of objects specified in advance as the obstacle 15, the suspicious person 16, etc., and when the shape of the specified object is detected in the video information acquired from the camera 11, the on-board image analysis unit 108 determines that the obstacle 15, the suspicious person 16, etc. has been detected. The on-board image analysis unit 108 may also determine that the obstacle 15, the suspicious person 16, etc. has been detected when it detects a characteristic change from the difference between video information acquired in the past and current video information. The on-board image analysis unit 108 may instruct the judgment unit 105 to simply change the profile 111 used by the output control unit 106 to one with higher image quality than the profile 111 currently being used, or may specify the number of each profile 111 if it can refer to the profiles 111 stored in the on-board memory unit 104.

[0100] 23 , in the on-board video transmission control device 100, only the on-board image analysis unit 108 acquires video information from the camera 11, and therefore the on-board image analysis unit 108 outputs the video information acquired from the camera 11 to the output control unit 106. Note that the on-board video transmission control device 100 may be configured so that the on-board image analysis unit 108 and the output control unit 106 can acquire video information from the camera 11, or the output control unit 106 may have the functions of the on-board image analysis unit 108 built in.

[0101] The determination unit 105 outputs the profile 111 selected based on the instruction of the on-board image analysis unit 108 to the output control unit 106 .

[0102] The subsequent operation of the on-board video transmission control device 100 is the same as in the third embodiment.

[0103] Next, a case where the terrestrial video reception control device 400 analyzes video information will be described. Fig. 24 is a block diagram showing an example configuration of the terrestrial video reception control device 400 according to embodiment 6. The terrestrial video reception control device 400 shown in Fig. 24 is obtained by adding a terrestrial image analysis unit 408 to the terrestrial video reception control device 400 shown in Fig. 18.

[0104] The ground image analysis unit 408 analyzes the video information received by the public 5G ground communication unit 401 or the train radio ground communication unit 402, and when it detects a specified object such as an obstacle 15 or a suspicious person 16 in the video information, it instructs the control unit 406 to change the profile 111 used in the on-board video transmission control device 100. For example, the ground image analysis unit 408 stores information on the shapes of objects specified in advance as the obstacle 15, the suspicious person 16, etc., and when it detects the shape of the specified object in the video information acquired from the public 5G ground communication unit 401 or the train radio ground communication unit 402, it determines that the obstacle 15, the suspicious person 16, etc. has been detected. The ground image analysis unit 408 may also determine that the obstacle 15, the suspicious person 16, etc. has been detected when it detects a characteristic change from the difference between previously acquired video information and current video information. The ground image analysis unit 408 may instruct the control unit 406 to simply change the profile 111 used by the on-board video transmission control device 100 to one with higher image quality than the profile 111 currently being used, or if it is possible to refer to the profiles 111 stored in the ground memory unit 405, it may specify the number of each profile 111, etc.

[0105] 24 , in the terrestrial video reception control device 400, the terrestrial image analysis unit 408 acquires video information from the public 5G ground communication unit 401 or the train radio ground communication unit 402, and therefore the terrestrial image analysis unit 408 outputs the video information acquired from the public 5G ground communication unit 401 or the train radio ground communication unit 402 to the matching unit 403. Note that the terrestrial video reception control device 400 may be configured so that the terrestrial image analysis unit 408 and the matching unit 403 can acquire video information from the public 5G ground communication unit 401 or the train radio ground communication unit 402, or the matching unit 403 may have the function of the terrestrial image analysis unit 408 internally.

[0106] The control unit 406 selects the profile 111 to be used by the on-board video transmission control device 100 from the ground storage unit 405 based on an instruction from the ground image analysis unit 408 .

[0107] The message generation unit 407 generates a message instructing the on-board video transmission control device 100 on the profile 111 to be used, and outputs the generated message to the public 5G ground communication unit 401 or the train radio ground communication unit 402.

[0108] The hardware configuration of the on-board video transmission control device 100 according to the sixth embodiment will be described. In the on-board video transmission control device 100, the on-board image analysis unit 108 is 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. Next, the hardware configuration of the terrestrial video reception control device 400 according to the sixth embodiment will be described. In the terrestrial video reception control device 400, the terrestrial image analysis unit 408 is 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.

[0109] As described above, according to this embodiment, at least one of the on-board image analysis unit 108 of the on-board video transmission control device 100 and the ground image analysis unit 408 of the ground video reception control device 400 analyzes video information and, based on the analysis results, can change the profile 111 used by the on-board video transmission control device 100 when converting video information. This allows the on-board video transmission control device 100 to obtain the same effects as in embodiment 3 or embodiment 4, and also reduces the operations performed by the on-board operator 14 in embodiment 3 or the ground operator 44 in embodiment 4.

[0110] 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.

[0111] 10, 10a, 10b Railway vehicle, 11 Camera, 11a Forward monitoring camera, 11b In-car security camera, 12 5G terminal, 13 Train radio terminal, 14 On-board operator, 15 Obstacle, 16 Suspicious person, 17 Conversion device, 20 Telecommunications carrier equipment, 21 5G area, 22 5G base station, 23 5G core, 24, 41 Router, 30 Train radio base station, 31 Train radio area, 40 Ground equipment, 42 Train radio control station, 43 Display device, 44 Ground operator, 50 Video transmission system, 90, 93 Processing circuit, 91 Processor, 92 Memory, 100 On-board video transmission control device, 101 Public 5G on-board communication unit, 102 Train radio on-board communication unit, 103 Measurement unit, 104 On-board memory unit, 105 Determination unit, 106 Output control unit, 107 Local 5G on-board communication unit, 108 On-board image analysis unit, 110 Status information, 111 Profile, 121 Conversion unit, 122 Selection unit, 400 Ground image reception control device, 401 Public 5G ground communication unit, 402 Train radio ground communication unit, 403 Matching unit, 404 Local 5G ground communication unit, 405 Ground memory unit, 406 Control unit, 407 Message generation unit, 408 Ground image analysis unit, 410 Railway vehicle information.

Claims

1. A ground video reception control device in a ground facility that manages the operation of railway vehicles, the ground video reception control device receiving video information from an on-board video transmission control device mounted on the railway vehicle and displaying the video information on a display device, a first ground communication unit that performs a first wireless communication according to a first wireless communication method and receives the video information; a second ground communication unit that performs second wireless communication by a second wireless communication method different from the first wireless communication method and receives the video information; a matching unit that converts the video information received by the first ground communication unit or the second ground communication unit into a format that can be displayed on the display device and outputs the converted video information to the display device; a ground storage unit in which one or more profiles describing video conversion parameters used in the on-board video transmission control device to convert the video information acquired by the on-board video transmission control device into an output format of the first wireless communication, and one or more profiles describing video conversion parameters used in the on-board video transmission control device to convert the video information acquired by the on-board video transmission control device into an output format of the second wireless communication are stored; a control unit that acquires operation information received by the display device from a ground operator of the ground facility from the display device, and selects the profile to be used by the on-board video transmission control device from the ground storage unit based on the operation information; a message generating unit that generates a message for instructing the on-board video transmission control device which profile to use, and outputs the generated message to the first ground communication unit or the second ground communication unit; A terrestrial video reception control device comprising:

2. the ground storage unit stores railway vehicle information which is information about the plurality of railway vehicles whose operation is managed by the ground facility; when selecting the profile for improving the image quality of the video information to be output to an on-board video transmission control device of a first railway vehicle in response to the operation information, the control unit selects the profile for lowering the image quality of the video information to be output to an on-board video transmission control device of a second railway vehicle other than the first railway vehicle and sharing the same communication band as the first railway vehicle, or determines to stop transmission of the video information, based on the railway vehicle information; the message generation unit generates a message for instructing an on-board video transmission control device of the second railway vehicle to use the profile for lowering image quality of the video information to be output, or a message for instructing the on-board video transmission control device of the second railway vehicle to stop transmitting the video information, and outputs the generated message to the first ground communication unit or the second ground communication unit.

2. The terrestrial video reception control device according to claim 1.

3. a ground image analysis unit that analyzes the video information received by the first ground communication unit or the second ground communication unit, and when an object defined in the video information is detected, instructs the control unit to change the profile used in the on-board video transmission control device; Equipped with The control unit selects the profile to be used by the on-board video transmission control device from the ground storage unit based on an instruction from the ground image analysis unit, the message generation unit generates a message instructing the on-board video transmission control device which profile to use, and outputs the generated message to the first ground communication unit or the second ground communication unit.

3. The terrestrial video reception control device according to claim 2.