JP2023093060A - Communication device and communication method - Google Patents

Abstract

To provide a communication device and a communication method with which it is possible to quickly transmit images.SOLUTION: According to an embodiment, a communication device that is installed in a mobile entity comprises a first communication unit, a second communication unit, a storage unit, and a processor. The first communication unit transmits and receives data to and from an external device which is installed on the ground. The second communication unit transmits and receives data to and from a camera. The storage unit stores the data. The processor is connected by a prescribed protocol to the camera through the second communication unit, and acquires, through the second communication unit, image data captured by the camera, compresses the image data to generate a compressed image, and stores the compressed image in the storage unit. When an acquisition command is received from the external device through the first communication unit, the processor transmits the compressed image which is stored in the storage unit to the external device.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD Embodiments of the present invention relate to a communication device and a communication method.

2. Description of the Related Art Some communication devices compress images captured by a camera that captures images in a train or the like according to a predetermined algorithm and transmit the compressed images to an external device. When such a communication device receives a request from an external device, it acquires an image from the camera, compresses the acquired image, and transmits it to the external device.

2. Description of the Related Art Conventionally, a communication device has a problem that it takes time to transmit a compressed image after receiving a request from an external device.

JP 2004-343494 A

In order to solve the above problems, a communication device and communication method capable of rapidly transmitting images are provided.

According to an embodiment, a communication device installed in a mobile includes a first communication unit, a second communication unit, a storage unit, and a processor. The first communication unit transmits and receives data to and from an external device installed on the ground. The second communication unit transmits and receives data to and from the camera. The storage unit stores data. The processor connects to the camera through the second communication unit using a predetermined protocol, acquires image data captured by the camera through the second communication unit, compresses the image data, and generates a compressed image. and stores the compressed image in the storage unit, and upon receiving an acquisition command from the external device through the first communication unit, transmits the compressed image stored in the storage unit to the external device.

FIG. 1 is a schematic diagram of a communication system according to an embodiment. FIG. 2 is a block diagram showing a configuration example of the communication system according to the embodiment. FIG. 3 is a sequence diagram illustrating an operation example of the communication system according to the embodiment; FIG. 4 is a flowchart illustrating an operation example of the gateway according to the embodiment;

Hereinafter, embodiments will be described with reference to the drawings.
A communication system according to an embodiment transmits an image captured by a camera to a server. Here, the communication system transmits an image captured by a camera installed in a train such as a train to a server installed on the ground. That is, the communication system transmits an image captured by the camera to the server in accordance with a request from the server installed on the ground.

FIG. 1 is a schematic diagram of a communication system 1 according to an embodiment. As shown in FIG. 1, the communication system 1 includes a server 20, a vehicle 100, and the like.

A vehicle 100 (moving body) is a vehicle that constitutes a train such as an electric train, Shinkansen, or monorail. A vehicle 100 includes a gateway 10, a camera 60, a door 101, and the like. The gateway 10 and camera 60 are communicably connected.

The gateway 10 (communication device) acquires the image captured by the camera 60 . Also, the gateway 10 transmits the image captured by the camera 60 to the server 20 according to the signal from the server 20 . Gateway 10 will be described in detail later.

A door 101 is an entrance of the vehicle 100 . That is, the door 101 is a door through which a user getting into the vehicle 100 or a user getting off the vehicle 100 passes. The door 101 opens and closes according to the operation of an operator such as a conductor.

Here, the door 101 is composed of eight doors 101a to 101h. Doors 101 a to 101 d are formed on a predetermined surface (first surface) of vehicle 100 . Further, the doors 101e to 101h are formed on a surface (second surface) facing the first surface.

Camera 60 photographs the interior of vehicle 100 . Camera 60 transmits the captured image to gateway 10 . The camera 60 is composed of eight cameras 60a to 60h. Cameras 60a to 60h capture images of users passing through doors 101a to 101h, respectively. For example, cameras 60a to 60h are installed above doors 101a to 101h, respectively.

For example, the camera 60 is composed of a CCD (charge coupled device) image sensor, a CMOS (complementary MOS) image sensor, or the like. For example, camera 60 captures a VGA (Video Graphics Array) image.

Also, the camera 60 may be equipped with a light or the like for illuminating the imaging area.
Moreover, the camera 60 may be one that captures an image of the central portion of the vehicle 100 . The number of cameras 60 or the imaging area is not limited to a specific configuration.

The server 20 (external device) manages images captured by the camera 60 . The server 20 transmits an acquisition command for acquiring an image from the camera 60 to the gateway 10 based on the operation of an operator or the like. Server 20 receives the response including the image from camera 60 from gateway 10 . The server 20 displays the image included in the received response on the display unit or the like.

FIG. 2 is a block diagram showing a configuration example of a control system of the communication system 1. As shown in FIG. As shown in FIG. 2, the communication system 1 includes a gateway 10, a server 20, a camera 60, and the like. The server 20 and camera 60 are as described above.

The gateway 10 includes a processor 11, a memory 12, an operation unit 13, a display unit 14, a first communication unit 15, a second communication unit 16, and the like. The processor 11, the memory 12, the operation unit 13, the display unit 14, the first communication unit 15, and the second communication unit 16 are communicably connected via a data bus or a predetermined interface.

In addition to the configuration shown in FIG. 2, the gateway 10 may further include a configuration according to need, or a specific configuration may be excluded from the gateway 10. FIG.

Processor 11 controls the operation of gateway 10 as a whole. For example, processor 11 controls camera 60 . Processor 11 also transmits images captured by camera 60 to server 20 under the control of server 20 .

For example, the processor 11 is composed of a CPU and the like. Also, the processor 11 may be composed of an ASIC (Application Specific Integrated Circuit) or the like. Also, the processor 11 may be composed of an FPGA (Field Programmable Gate Array) or the like.

The memory 12 (storage unit) stores various data. For example, memory 12 functions as ROM, RAM and NVM.
For example, the memory 12 stores control programs, control data, and the like. A control program and control data are installed in advance according to the specifications of the gateway 10 . For example, the control program is a program that supports functions implemented by gateway 10 .

The memory 12 also temporarily stores data being processed by the processor 11 . The memory 12 may also store data necessary for executing the application program, execution results of the application program, and the like.

The memory 12 also stores a storage area 12a for storing image data (for example, a VGA image) captured by the camera 60 and a compressed image obtained by compressing the image data (for example, a QVGA (Quarter VGA) image). and a storage area 12b for storing data.

The operation unit 13 receives input of various operations from the operator. The operation unit 13 transmits a signal indicating the input operation to the processor 11 . The operation unit 13 is composed of a keyboard, buttons, a touch panel, or the like.

The display unit 14 displays information based on control from the processor 11 . For example, the display unit 14 is composed of a lamp or a liquid crystal monitor. When the operation unit 13 is composed of a touch panel, the display unit 14 is composed of a liquid crystal monitor integrally formed with the operation unit 13 .

The first communication unit 15 is an interface for transmitting and receiving data to and from the server 20 . For example, the first communication unit 15 is an interface for connecting to the network to which the server 20 is connected. For example, the first communication unit 15 wirelessly connects to the server 20 .

The second communication unit 16 is an interface for transmitting and receiving data to and from the camera 60 . For example, the second communication unit 16 connects to the camera 60 by wire. For example, the second communication unit 16 is an interface that supports LAN (Local Area Network) connection, USB (Universal Serial Bus) connection, or the like.

Next, functions realized by the gateway 10 will be described. The functions realized by the gateway 10 are realized by the processor 11 executing a program stored in the memory 12 or the like.

First, the processor 11 has a function of connecting (joining) to the camera 60 .

When the processor 11 receives a predetermined command (connection command) from the server 20 through the first communication unit 15, it connects to the camera 60 by IGMP (Internet Group Management Protocol) (predetermined protocol).

Also, the processor 11 sets the port to be connected to each camera 60 . Processor 11 connects with each camera 60 through a port unique to each camera 60 . That is, the processor 11 recognizes in advance the port to which each camera 60 is connected. The processor 11 connects through the port to the camera 60 corresponding to the port.

Processor 11 may also group cameras 60 . For example, the processor 11 groups the cameras 60 (cameras 60a to 60d) formed on the first surface as the first group. The processor 11 also groups the cameras 60 (cameras 60e to 60h) formed on the second surface as a second group.

The processor 11 also has a function of acquiring image data captured by the camera 60 .

When connected to the camera 60, the processor 11 transmits a command to the camera 60 to take a picture. Camera 60 takes an image according to the command and transmits the image data to processor 11 .

Processor 11 acquires image data from camera 60 . After obtaining the image data, the processor 11 stores the obtained image data in the storage area 12a.

After storing the acquired image data in the storage area 12a, the processor 11 acquires the image data from the camera 60 again. For example, processor 11 acquires image data from camera 60 at predetermined intervals (eg, 6 FPS).

The processor 11 stores the acquired image data in the storage area 12a again. The processor 11 may overwrite image data stored in the past. Further, when the storage area 12a stores a predetermined number of pieces of image data, the processor 11 may delete the oldest image data and store new image data in the storage area 12a.

The processor 11 also has a function of compressing image data.

After obtaining the image data, the processor 11 compresses the image data according to a predetermined algorithm to generate a compressed image. For example, processor 11 produces a QVGA image as a compressed image.

Processor 11 may generate a compressed image by reducing the resolution of the image data. Also, the processor 11 may generate a compressed image while maintaining the resolution of the image data. The method by which the processor 11 generates the compressed image is not limited to any particular method.

After generating the compressed image, the processor 11 stores the generated compressed image in the storage area 12b.

After storing the generated compressed image in the storage area 12a, the processor 11 waits until new image data is obtained. Upon obtaining the new RAW, processor 11 compresses the new image data to produce a compressed image.

The processor 11 stores the generated compressed image in the storage area 12b again. The processor 11 may overwrite a previously stored compressed image. Further, when the storage area 12b stores a predetermined number of compressed images, the processor 11 may delete the oldest compressed image and store a new compressed image in the storage area 12b.

The processor 11 also has a function of transmitting an image captured by the camera 60 to the server 20 .

The processor 11 receives a command (acquisition command) for acquiring an image captured by the camera 60 from the server 20 through the first communication unit 15 .

The acquisition command designates an image to be acquired from the images captured by each camera 60 . That is, the get command selects one or more cameras 60 from multiple cameras 60 . For example, the acquisition command may specify the port number (port number) to which the camera 60 that captures the image to be acquired is connected. Also, the acquisition command may designate a group of cameras 60 that capture images to be acquired. Also, the acquisition command may acquire each image captured by each camera 60 .

Also, the acquisition command designates image data or a compressed image as an image to be acquired. Also, the acquisition command may specify both the image data and the compressed image.
Also, the acquisition command may acquire the latest image or acquire a past image.

The processor 11 acquires the image data or the compressed image from the storage area 12a or the storage area 12b according to the acquisition command. The processor 11 transmits a response including the acquired image data or compressed image to the server 20 through the first communication unit 15 .

The processor 11 maintains the connection with the camera 60 even after transmitting the response to the server 20 .

First, the processor 11 has a function of disconnecting (leaving) the connection with the camera 60 .

When the processor 11 receives a predetermined command (release command) from the server 20 through the first communication unit 15 , the connection with the camera 60 is released.

Next, an operation example of the communication system 1 will be described.
FIG. 3 is a sequence diagram for explaining an operation example of the communication system 1. FIG.

First, the server 20 transmits a connection command to the gateway 10 (S11).

Processor 11 of gateway 10 receives the connection command through first communication unit 15 . Upon receiving the connection command, the processor 11 connects to the camera 60 through the second communication section 16 (S12).

When the processor 11 is connected to the camera 60, the camera 60 transmits the captured image data to the gateway 10 (S13).

The processor 11 of the gateway 10 acquires image data through the second communication section 16 . After acquiring the image data, the processor 11 stores the acquired image data in the storage area 12a (S14).

After storing the acquired image data in the storage area 12a, the processor 11 compresses the acquired image data to generate a compressed image (S15). After generating the compressed image, the processor 11 stores the compressed image in the storage area 12b (S16).

Here, the server 20 transmits an acquisition command for acquiring an image to the gateway 10 (S17).

The processor 11 of the gateway 10 receives the acquisition command through the first communication section 15 . Upon receiving the acquisition command, the processor 11 transmits a response including image data or a compressed image to the server 20 according to the acquisition command (S18).

Here, the server 20 transmits a release command to the gateway 10 (S19).

Processor 11 of gateway 10 receives the release command through first communication unit 15 . Upon receiving the release command, the processor 11 releases the connection with the camera 60 according to the release command (S20).

When the processor 11 disconnects from the camera 60, the communication system 1 terminates its operation.

Next, an operation example of the gateway 10 will be described.
FIG. 4 is a flowchart for explaining an operation example of the gateway 10. As shown in FIG.

Assume here that the processor 11 of the gateway 10 is not connected to the camera 60 .

First, the processor 11 determines whether or not a connection command has been received from the server 20 through the first communication unit 15 (S21). When determining that the connection command has not been received (S21, NO), the processor 11 returns to S21.

When determining that the connection command has been received (S21, YES), the processor 11 connects to the camera 60 through the second communication section 16 (S22). When connected to the camera 60, the processor 11 acquires image data captured by the camera 60 through the second communication unit 16 (S23).

After obtaining the image data, the processor 11 stores the obtained compressed image in the storage area 12a (S24). After storing the acquired compressed image in the storage area 12a, the processor 11 compresses the acquired image data to generate a compressed image (S25).

After generating the compressed image, the processor 11 stores the generated compressed image in the storage area 12b (S26). After storing the generated compressed image in the storage area 12b, the processor 11 determines whether an acquisition command has been received through the first communication unit 15 (S27).

When determining that the acquisition command has been received (S27, YES), the processor 11 transmits a response including image data or a compressed image to the server 20 through the first communication unit 15 according to the received acquisition command (S28).

If it is determined that the acquisition command has not been received (S27, NO), or if a response including image data or a compressed image has been sent to the server 20 (S28), the processor 11 cancels through the first communication unit 15. It is determined whether a command has been received (S29).

When determining that the release command has not been received (S29, NO), the processor 11 returns to S23.

When determining that the release command has been received (S29, YES), the processor 11 releases the connection with the camera 60 (S30). After disconnecting the camera 60, the processor 11 terminates its operation.

Note that the processor 11 may execute S23 to S26 and S27 to S29 in parallel. In this case, when the processor 11 receives the release command (S29, YES), it stops S23 to S26.

After connecting to the camera 60 (S12, S22), the processor 11 may transmit to the server 20 a response indicating connection to the camera 60 through the first communication unit 15. FIG.

After disconnecting from the camera (S30), the processor 11 may transmit to the server 20 a response indicating that the connection with the camera 60 has been terminated through the first communication unit 15. FIG.

The connection command may also specify an algorithm for compressing the image data. In this case, processor 11 compresses the image data according to the algorithm specified by the connection command to generate a compressed image.

Also, the connection command may specify whether or not compression is necessary. If the connection command specifies that image data compression is not required, processor 11 does not compress the image data. That is, the processor 11 does not execute S15 and S16 (S25 and S26).

Also, the server 20 may transmit to the gateway 10 a command to change the algorithm for compressing the image data or whether compression is necessary while the connection between the gateway 10 and the camera 60 is maintained. The processor 11 of the gateway 10 changes the algorithm for compressing the image data or the necessity of compression according to the command.

Also, the gateway 10 or the camera 60 may be installed at a location other than the vehicle 100 . For example, gateway 10 or camera 60 may be installed on a ship, aircraft, building, or the like. The location where gateway 10 or camera 60 is installed is not limited to a particular configuration.

The gateway thus configured acquires and compresses the image before receiving the command to acquire the image from the server. When the gateway receives the command from the server, it sends the pre-acquired image or the pre-compressed image to the server. As a result, the gateway can send images quickly in response to commands from the server.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1 communication system 10 gateway 11 processor 12 memory 12a storage area 12b storage area 13 operation unit 14 display unit 15 first communication unit 16 second second Communication unit 20 Server 60 (60a to h) Camera 100 Vehicle 101 (101a to h) Door.

Claims (9)

A communication device installed in a mobile body,
a first communication unit that transmits and receives data to and from an external device installed on the ground;
a second communication unit that transmits and receives data to and from the camera;
a storage unit for storing data;
connecting to the camera with a predetermined protocol through the second communication unit;
Acquiring image data captured by the camera through the second communication unit,
After decompressing the image data, recompressing as necessary to generate a compressed image,
storing the compressed image in the storage unit;
transmitting the compressed image stored in the storage unit to the external device when an acquisition command is received from the external device through the first communication unit;
a processor;
A communication device comprising: the acquisition command is a command for acquiring the image data or the compressed image;
The processor
storing the image data in the storage unit;
transmitting the image data or the compressed image stored in the storage unit to the external device according to the acquisition command;
A communication device according to claim 1 . The processor acquires the image data at predetermined intervals through the second communication unit, compresses the image data to generate the compressed image, and stores the compressed image in the storage unit.
A communication device according to claim 1 . The camera is composed of a plurality of cameras,
the get command selects one or more cameras from the plurality of cameras;
The processor transmits the compressed image corresponding to the camera selected by the acquisition command to the external device through the first communication unit.
4. A communication device according to any one of claims 1 to 3. When the processor receives a connection command through the first communication unit, it connects to the camera.
5. A communication device according to any one of claims 1 to 4. the processor disconnects from the camera upon receiving a disconnection command through the first communication unit;
6. A communication device according to any one of claims 1-5. the predetermined protocol is IGMP;
7. A communication device according to any one of claims 1-6. The camera shoots the inside of the vehicle that constitutes the train,
8. A communication device according to any one of claims 1-7. A communication method executed by a processor of a communication device installed in a mobile body,
Connect to the camera with the prescribed protocol,
obtaining image data captured by the camera;
compressing the image data to generate a compressed image;
storing the compressed image in a storage unit;
when receiving an acquisition command from an external device installed on the ground, transmitting the compressed image stored in the storage unit to the external device;
Communication method.

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